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Domiciliary treatment of pulmonary tuberculosis with combined chemotherapy
December 1951
256
Domiciliary Treatment of Pulmonary Tuberculosis with Combined Chemotherapy By DAVID L. PUGH Chest Physician, Mid-Kent Area, South-East Metropolitan Regional Hospital Board, at the Chest Clinic, Maidstone Honorary Clinical Assistant, Brompton Hospital. E. R. JONES
Consultant Pathologist, South-East Metropolitan Regional Hospital Board, at the Kent County Laboratory, Maidstone With Approval of the Statistical Evidence by W. J. MARTIN From the Medical Research Council's Statistical Research Unit, London School of Hygiene and Tropical Medicine TABLE I In a recent communication [i] on the PAS and assessment of Sodium PAS as a domiciliary Sodium PAS and thiosemi- Triple measure in the treatment o f a d u h puhnonary Group PAS slreplono'cbz carbazone combined tuberculosis, we put forward the concept that A 27 z6 lo 4 no one agent could be considered to be a B 9 2 4 z panacea for the treatment of tuberculous lesions; rather it is necessary for a planned Total 36 x8 x4 5 combined operation of various methods, making adjustments as and when necessary R e g i m e n o f Treatment to meet the different manifestations of the Three drugs were used in this investigation disease. Under such a system, combined as shown on Table I; 36 cases were given chemotherapy has, we believe, a definite and sodium PAS alone, 18 sodium PAS and valuable place, and its use is justified as a streptomycin and 14 PAS and thic/semitherapeutic and preventive measure. To carbazone (TBI/698) and 5 the triple comthat end we have extended our regimen of bination of sodium PAS, streptomycin and treatment and. accordingly our observations TB I/698. include various combinations of the drugs These drugs were given as follows: available and the findings obtained form the basis of this report. (i) Sodium P A S . - T h e dosage consisted The patients were classified into two of x2 grammes daily for a period of twelve groups according to the type of lesion- weeks, given in cachet form (prepared by Group A, of chronic exudative lesions with Herts Pharmaceuticals Limited) in four or without cavitation and Group B, consist- doses of 3 grammes each. This was combined ing of cases already receiving some form of with x rag. vit. BI daily throughout tile collapse therapy who have been given course, prolonged administration of sodium chemotherapy as a supporting measure. PAS tending to produce a vit. B deficiency. The patients in each of the tWO groups 9 Mist. pot. cit. 89fluid ounce three times daily have been divided into four series dependent after meals was also given during the last on the method of treatment adopted as two weeks of the course in the belief that shown in Table I. such alkalinization of the urine might It will be observed that each series may prevent albuminuria and haematuria. With thus be compared with each of the other this method the toxic effects to which refertreated series. In each series the type of ence was made in our previous comnmnicalesion is similar. tion [2] occurred infrequently and consisted
December
1951
T U BERC LE
of mild gastro-intcstinai upset during the first three weeks of treatment. This was controlled by Benadxs, l given as 5o mg. capsules b.d. in most cases and in those not responding quickly to this treatment the dosage was reduced to one-half with a gradual increase in amount each day, until the normal dosage was obtained. (2) Sodium PAS and Streptono'cin. - Sodium PAS was given in the dosage mentioned above, and continued for a period of sixteen ~,vecks. Strcptomycin was givcn as DihydroStrcptomycin Sulphate ( G l a x o ) i n a daily dosagc of i grammc intramuscularly for thc first six wccks and the last six wccks of thc coursc, sodium PAS bcing givcn alonc for thc intcrvcning four w c c ~ ' pcriod. (3) Sodium PAS and ~ Thiosemicarbazone ( T B z / 6 9 8 ) . - S o d i u m PAS was given as above for a period of twenty-six weeks. rI"hiosemicarbazone (Herts Pharmaceuticals Limited) was commenced at the same-time as PAS and in the following dosage, 5 ~ mg. daily for the first week, zoo mg. for the second week, 15o mg. for the third week, and 2oo rag. for the following twenty-three weeks of the course subject to laboratory investigation to which reference will be made below. (4) Sodium PAS, Streptomycin and TB1]698 (triple combined therapy). - The dosage for the three drugs was that set out above, the treatment being continued for sixteen weeks. Toxk side-effects of thc thrcc drugs conccrncd arc varicd and in some cascs of scrious import to thc paticnt. In thc PAS scrics, onc paticnt in Group A and thrce i n Group B had gastro-int.estinal upsets which responded to treatment. In addition, one patient in Group A demonstrated a confusional state in the twelfth week of the course. In the PAS and streptomycin series, one patient in Group A and one in Group B showed gastro-intestinal symptoms which responded to the regimen described above.
257
One patient in Group A also had vertigo but this disappeared oxl reduction of the streptomycin to o. 5 grannne daily for three weeks and did not return when the dose was subsequently raised to I.O gramme daily. In the PAS and TBx ]698 series, 3 patients in Group A showed toxic changes suggestive of liver damage as revealed b y a positive serum colloidal gold reaction. One of these patients was unable to complete the full course of TBz]698 and was given PAS alone. I11 addition, I patient in Group A and I in Group B had mild gastro-intestinal disturbance. In the triple combined series, one patient in Group A showed hallucinations and vertigo with deafness late in the course. These symptoms disappeared when the antibiotic was withhelcl though the PAS was continued. A report on this case showed that the patient was suffering from streptomycin 'drunkenness', resulting from a degeneration of the vestibular section of the eighth cranial nerve, with some associated involvement of the basal turn of the cochlea. In this series also, one patient in Group B showed a mild gastro-intestinal disturbance and the same patient showed an allergic response to thiosemicarbazone, revealed by the presence of a papular eruption with conjunctivitis. This condition responded to a reduction of the dosage from 2oo mg. daily to zoo mg. daily for three weeks and did not return 'when the dose was increased by the usual stages to the 2oo mg., which dosage was maintained until the end of the course with no recrudescence of symptoms. The results of the clinical, radiological and laboratory investigations may now be reviewed. Combined Clinical and Radiological Assessment
Table II gives the results obtained from an assessment of the combined clinical and radiological findings, the former being based on the weight changes, the erythrocyte sedimentation rate (Westergren) and the
258
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December 1951
TABLE II.--CLINICAL AND R A D I O L O G I C A L ASSESSMENT PAS and PAS and Triple PAS streptono'cin TB I/698 combined NC D T I NC D T I NC D T I NC D T
Group
I
A
i6
9
,2
27
12
4
o
z6
8
2
o
IO
2
2
o
B
6
3
o
9
,2
o
o
~
3
I
o
4
l
o
o
l
Total 22 Percent 6I
i2 32
,2 6
36 ~
o o
z8 ~
zz 79
3 2x
o o
14 3 - - 6o
2 4~
o o
5 --
I4 4 78 ,22
4
I = improved. NC = no change. D = deterioration. T = Total. Assessment based on - l, weight. 2, E.S.R. 3, sputum. 4, x-ray findings. sputum results. These four factors, which were given equal value in the assessment, were chosen so that the errors of subjective vfiluation may be overcome. It will be scen from the table that 2 patients in Group A of the PAS series showed deterioration. In the PAS series, 22 (6z per cent) out of 36 patients were found to be improved and I2 (32 per cent) showed no change. In the PAS and streptomycin series, 14 (78 per c e n t ) o u t of z8 showed improvement and 4 (2,2 per cent) showed no change. In the PAS and thiosemicarbazone series, I I (79 per cent) out of 14 improved while 3 (2I per cent) were unchanged, and in the small triple combined series 3 out of 5 patients improved and 2 showed no change. A more detailed analysis of the contributing factors in this assessment revealed interesting features. Gain in weight was most marked in the PAS and thiosemicarbazone series, tile next best being the PAS and streptomycin series, but tile difference is not statistically significant. The erythrocyte sedimentation rate was reduced to the greatest extent in the PAS and streptomycin series, the only change of significance. Marked changes occurred in the sputum resuhs in all groups. There was a reduction in the number Of patients with a positive sputum after treatment, and a significant rise in the number showing a negative sputum or no sputum. Excluding the small triple combined series this change was largest in the PAS and thiosemicarbazone series, next in the PAS and streptomycin series and next in the PAS series. For allseries the combined
number of patients with positive sputum decreased from 46 (63 per cent) before treatment to 12 (I 6 per cent) after treatment, a statistically significant difference.
Radiological Assessment Table I I I shows the results of this assessment and reveals a marked improvement in all series as the result of t r e a t m e n t ; i n no case was any deterioration found. A radiological improvement in 6o per cent or over of the cases in the type of lesion treated is an indication of the success of the therapeutic regimen adopted, though it would have been more convincing had it been poss!ble to have had larger numbers in some of the series. The figures reveal an improvement in both groups. In the PAS series 28 (78 per cent) out of 36, PAS and streptomycin series t6 (89 per cent) out of I8, PAS and thiosemicarbazone series 13 (93 per cent) out of z4, and triple combined series 3 out of 5 cases showed improvement. Thus tile improvement was most marked in the PAS and thiosemicarbazone and the PAS and streptomycin 9 serics.
Cavitation
Table IV shows the presence of cavitation in patients in each series and in each group before treatment and after treatment. In the PAS series half the number of patients in each group showed cavitation, and in these in approximately 25 per cent cavity closure was obtained. In the PAS and streptomycin series z3 out of I8 patients showed cavitation and in only 2 was there cavity closure. The PAS and thiosemicarbazone series gave a
December 1951
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259
TABLE I I I - X-RAY ASSESSMENT PAS and PAS and streptomycin thiosemicarbazone T I NC D T I NC D T I
Sodium PAS NC D
Triple combined NC D T
Group
I
A B
"20 8
7 1
o o
27 9
14 2
2 o
o o
16 2
9 4
z o
o o
1o 4
,, z
2 o
o o
4 1
28 78
8 22
o o
36 --
z6 89
2 I1
o o
z8 --
13 93
1
o o
14 --
3 6o
2 4~
o o
5
7
Total Per cent
I = improved. NC = no change. D = deteriorated. T = Total. *I'ABLE IV - CAVITATION
Series Groups Total .... Cavity present .. Cavity closure 99 Cavity persisting ..
Sodium PAS A B T
PAS and streptomycin A B T
27 I3 3
9 4 3
36 x7 6
i6 ix 2
2 2 o
18 x3 2
io 9 4
4 i o
x4 IO 4
4 4 o
x z I
5 5 I
zo
I
Iz
9
2
I
5
I
6
4
o
4
b e t t e r result in that 4 ~ p e r cent showed cavity closure, while in the triple c o m b i n e d series the cavity was closed in I case in 5. T h e r e was a close a p p r o x i m a t i o n o f the p e r c e n t a g e i m p r o v e m e n t shown in all series, the best results being o b t a i n e d with the combinations o f PAS with streptomycin and PAS a n d thiosemicarbazone. T h e observations confirmed the desirability o f c o m b i n e d c h e m o t h e r a p y in the t r e a t m e n t o f p u l m o n a r y tuberculous lesions. Laboratory
Investigations
In addition to s p u t u m examinations for tubercle bacilli, certain o t h e r l a b o r a t o r y investigations were carried out during this investigation. These i n c l u d e d culture o f tubercle bacilli with special reference to t h e d e v e l o p m e n t o f bacillary resistance to the drugs employed, and, in the case of those patients receiving T B I / 6 9 8 , liver function tests in view o f the possibility o f liver d a m a g e developing as reported b y the G e r m a n clinicians.
Haematology A total c o u n t o f red cells a n d leucocytes, a differential c o u n t and a h a e m o g l o b i n estimation were m a d e on three occasions on all patients receiving PAS a n d PAS plus streptomycin, one i m m e d i a t e l y before the
PAS and thiosemicarbazone combined A B T A B T
c o m m e n c e m e n t o f treatment, one n e a r the
middle o f the course and the third within a d a y or two o f completing the course. I n the" case o f patients receiving thiosemicarbazonethe above blood examinations were m a d e at: m o n t h l y intervals with leucocyte and differential counts, haemoglobin estimation a n d m e a n corpuscular haemoglobin concentration on each o f the intervening weeks. Tile more f r e q u e n t tests on thiosemicarbazone patients were m a d e because cases o f h a e m o lyric a n a e m i a and agranulocytosis had been r e p o r t e d by G e r m a n workers, a n d we had no previous experience o f the use o f this drug. With the dosage of thiosemicarbazone used, no cases o f agranulocytosis or of severe haemolysis, due to the possible liberation o f p h e n y l h y d r a z i n e as a b r e a k d o w n p r o d u c t o f the thiosemicarbazone, were encountered d u r i n g this investigation.
Culture and Development to Drugs
of
Resistance
Specimens o f s p u t u m were obtained whenever available d u r i n g the course o f t r e a t m e n t for microscopic and cultural examination, a n d w h e n positive p r i m a r y cuhures were obtained, the sensitivity o f the organisms to the various drugs were tested by the m e t h o d described previously [2]. Sensitivity to PAS
260
T U B ERC L E
was dctcrmined on Lowenstein's nacdium containing varying concentrations of PAS. This medium proved unsatisfactory for the determination of streptomycin sensitivity and Herrold's egg-yolk agar gave better results. Both these solid media were found unsuitable for TBI/698 sensitivity tests and Dubos' fluid media was used. On these media and using the technique described (loc. cit.) normal tubercle bacilli, isolated from patients who had not received any of the drugs, were found to be sensitive to o.~ 5 rag. and resistant to o.o25 mg. PAS per IOO ml. medium, sensitive to 5 units and resistant to i unit streptomycin per ml. medium, sensitive to o.I and resistant to o.oi ing. TBI/698 per IOO ml. medium. Many of the patients had no sputum shortly after commencing treatment, others were microscopically and culturally negative throughout, and from some on combined therapy specimens were not always available during the period when the patients happened to be on two or more drugs at tile same time. In 4 cases microscopic examination was positive but the organism failed to grow on an artificial medium, and from a fifth patient, one specimen was microscopically positive and culturally negative, whereas previous specimens were positive both microscopically and on culture. In all these specimens, microscopic examination revealed mainly morphologically degenerate forms of bacilli. In a previous investigation on the development of strains of tubercle bacilli resistant to PAS [2] it was stated that over the limited period during which the cases had been followed, the indications were that once resistant strains had developed, the change in the nature of the organisms was permanent. A m o r e extended follow-up of these cases showed that this was not ahvays the case. After an interval of three to five months without PAS, the resistance of the tubercle bacilli retttrned more or less to their original level, but increased when the patients were put on PAS again.
December 1951
In the same investigation it was stated that 5 cases where tubcrcle bacilli resistant to 6"4 rag. PAS per IOO ml. were given a further course of PAS since the patients were to have a course of streptomycin in the hope that the PAS might prevent the development of strains resistant to streptomycin. It has been found, however, that PAS does not prevent the development of streptomycin-resist ant strains. It is not possible to give a simple classification of the results obtained from our sensitivity tests, but the following general statements may be made: (I) In most, but not all, cases after prolonged use (up to six months) the tubercle bacilli develop a resistance to PAS greater than tile average therapeutic level obtainable in the serum of the patient. (2) PAS used in conjunction with streptomycin or TBI/698 does not prevent the development of resistance to the latter chemotherapeutic agents, nor is the resistance of the bacilli to PAS influenced by the simultaneous administration of streptomycin or TBI/698. (3) O f the 4 cases in which resistance tests to PAS and TBI/698 could be carried out, one developed a strain resistant to o.I rag. and sensitive to I mg. per cent TBr/698; jn the other 3 cases, when examined, the organisms were of normal resistance. Liver Function Tests
The liver function tests carried out weekly on all patients on TBI/698 were albumin and globulin estimations, serum colloidal gold tests, alkaline phosphatase estimations, and bilirubin determinations when considered necessary. The serum of these patients has a greenish-yellow tinge and several quantitative van den Bergh tests were carried out, but in no case was the bilirubin content increased above the normal. The serum colloidal gold reaction is a sensitive indicator of active hepatic disease and a strongly positive reaction is considered to be almost diagnostic of parenchymatous
December 1951
TUBERCLE
261
O f the x8 patients in.the PAS and streptodisease. Hence cases who had more than a I + colloidal gold before treatment were not mycin series, 2 had an existing thoracoplasty put on TBI/698 except in one case who had and 3 were recommended for this operation. a 3-t- reaction. After five weeks' treatment, 4 patients were given a further course of this patient's serum colloidal gold reaction chemotherapy, 3 being given PAS and was 5 + and further treatment with TBI/698 streptomycin and x being given PAS and thiosemicarbazone. The remainder had no was discontinued. Two cases showed a 2 + further form of active treatment. and 5 a I + reaction during treatment. O f the 14 patients in the PAS and thioA raised serum alkaline phosphatase is found in various types of liver damage in- semicarbazone series, 2 patients had an A.P. cluding tuberculosis. None of the patients in maintained, 2 had an A.P. abandoned, 2 the series had a phosphatase level above 13 were recommended for thoracoplasty and units, the upper limit of normal, before the one for PAS and streptomycin. The remaincommencement of treatment. During treat- der had no further form of active treatment. In the small triple combined series of 5 ment, there were marked weekly variations, some rising slightly above 13 units, and then patients, i had an A.P. maintained and the falling except in one case where the level same patient had a collapse of the other rose steadily to 37 units, but even in this lung by means o f a n osteoplastic pneumolysis, case, there w a s no clinical evidence of and one patient was given a course of PAS and thiosemicarbazone. The remainder had increasing liver damage. Before treatment 12 of the 19 patients no further form of active treatment. In no case were the results of this Second had an albumin-globulin ratio of less than course of chemotherapy included in this I to I, but after treatment the ratio was report even though the combination differed greater than x to I in 15 of the 19 patients, from thai of the original course. thus confirming the findings of previous workers that Till/698 tends to reverse the Discussion albumin-globulin ratio in the direction of The problem of the evaluation of any drug normal. or combination of drugs in the treatment of As all these TBI/698 patients were having pulmonary tuberculosis is difficult and it is either PAS or streptomycin as well, it is not only after a considerable time has elapsed possible to assess how much these changes that it may be possible to make a conclusive were due to the TBI/698 alone. statement that might be of scientific value. It is, however, established that chemotherapy C o n t i n u a t i o n of T r e a t m e n t is an effective means of treating pulmonary At the end of the course of treatment the tuberculosis under certain conditions, though patients in each series were kept under it is only one method; all other proved observation and close surveillance and were methods continue [o be necessary and cannot divided into three sub-sections-those re- be discarded at the present time. As the quiting no further active treatment, those report of the clinical sub-committee of requiring further chemotherapy and t h o s e Antimicrobial Therapy in Tuberculosis of requiring some other form of treatment. the American Trudeau Society [3] states: In the PAS series, of the 3 6 patients, one 'the administration of antimicrobial ~/gents had an existing A.P. continued and one should be carefully correlated with an overalready had a thoracoplasty. 3 patients had all programme of medical and surgical their A.P. abandoned, 5 were recommended treatment. The emergence of drug-resistant for thoracoplasty, and 3 were given a further strains of the tubercle bacilli may be delayed course of chemotherapy, PAS and strepto- by the simultaneous administration of certain mycin. The remainder had no further form combinations of antimicroblals and the best combination available today is one of of active treatment.
262
T U B ERC L E
the streptomycin drugs together with some form of PAS.' The report advocates this treatment being undertaken in hospital, but Westergren [4] has stated that 'in favourable circumstances such treatment may be conducted outside hospital' with the proviso that only doctors with experience in this field should plan and observe the effects of chemotherapy in tuberculosis. Heilmeyer [5] believes that while permanent cure with chemotherapy alone may be obtained in cases free from cavities, the majority of cavitating lesions require some form of surgery for their elimination. Lesions of recent origin respond better than those of long duration and it may be that these lesions show improvement on conservative measures alone. Chemotherapy, however, reduces the time factor in such lesions by producing stabilization much earlier. Furthermore, it is unwise to withhold a proven regimen of treatment in the interest of conservatism if there is reason to fear that progressive disease is likely to develop. Chemotherapy is also of value in" supporting existing collapse therapy and may be used as an 'umbrella' to cover the abandonment of collapse therapy rendered necessary by spontaneous obliteration of the pleural space or the evidence of a frozen hmg. The present review demonstrates clearly the value of domiciliary combined chemotherapy in exudative lesions and as a support for existing collapse therapy. The present results reveal marked improvement in all tile series of cases by clinical, radiological and laboratory findings. Each case has been initially reviewed in the light of a 'planned combined operation' of treatment, in which bed-rest and chemotherapy at home have formed the first and early stages, progressing where necessary to active surgical intervention. Success is not claimed in all cases, but there is to be found in the data ample justification for the procedure adoptcd. In an 'over-all' review of the series, we believe that the combinations of PAS and streptomycin and PAS and thiosemicar-
December 1951
bazone are the most effective. The results of the latter series have been more favourable than we anticipated at the outset, while the triple combined series, included as a matter of interest, is too small for statistical significance. Toxic effects due to the drugs used have been negligible, only one severe case of neurotoxicity to streptomycin and only one case of hepatic damage possibly due to thiosemicarbazone having occurred. VCe have observed, however, the onset of a manic-depressive type of syndrome in 2 of the cases in the series and in x other not included owing to his admission to hospital for the further treatment of his tuberculous lesion. In all these cases, PAS has formed the basis of treatment and we do not believe that the symptoms are attributable to the salicylic radicle; rather is it a confusional state arising as a delayed reaction at the end of a twelve weeks' course of treatment or when tile stress of a return to take up a normal position in the economic world proves to be too great. One further theory may be added. The work of Hetzel and Hine [6] postulates that the therapeutic effects of salicylates occur by virtue of their stimulation of the pituitary and suprarenal glands. This concept finds no support from the experiments of Meade and Smith [7]. If, however, this theory is proven then it may well be that the prolonged stimulation of these glands by Na PAS therapy may cause a decrease in their secretion due to over-stimulation with the production of hypocorticoidism. This condition may, according to Selye [8], give rise to mental symptoms such as sudden psychic disturbances including acute spells of maniac excitement, in which the ability of concentration and thinking is impaired. Whether the syndrome is connected with stimulation of the pituitary gland by the PAS, or with the hypopotassaemia which may accompany the treatment, or is a toxic confusional state, are matters for further investigation. Cavitating lesions have not responded as a general rule, the number of cases in which there has been cavity closure being limited.
December 1951
T U BERC L E
263
Resistant strains of the tubercle bacillus have developed and the use of PAS in conjunction with streptomycin and thiosemicarbazone does not prevent the development of resistance to the latter agents. The change Summary in nature of the organisms in response to The domiciliary use of combinations of PAS therapy is not always permanent. chemotherapeutic agents in the treatment Our thanks are due to the members of the of pulmonary tuberculosis is reviewed. staffs of the Maidstone Chest Clinic, and the The majority of patients in all series Kent County Laboratory, and the Pharmashowed improvement by clinical, radiologieal cist of the West Kent General Hospital for and laboratory findings. their continued assistance. The regimen of treatment adopted formed part of a 'planned combined operation'. References Fhe combinations of PAS with strepto- [I] Pugh, D. L.,Jones, E. R., and Martin, W . j . (195o) Lancet, II, 92. mycin and PAS with thiosemicarbazone [2] Pugh, D. L., Jones, E. R., and Martin, W.J. (x95z) were found to be most effective, the latter Tubercle, xxxH (3), 5 ~ Trudeau Society (z95 Q American Review of being more favourable than originally [3] American Tuberculosis,/_xm, 5, 6z7. [4] Westergren, A. (195o) Word. Med., x/-m, 4o3 . anticipated. [5] lleilmeyer, L. 095 o) LM.H;, eL, 75, 473. Toxic side-effects have been negligible. [6] Itetzel, B. S., and Iline, D. C. (195 l) Lancet, u, 94. Cavitating lesions have not shown a good [7] Meade, B. W., and Smith, M. J. II. (195 Q Lancet, Letters to the Editor, n, 224. response but surgical intervention had been [8] Selye, H. (x949) Textbook of Endocrinology. made possible as a result of chemotherapy. Montreal, Ed. n, 147.
Surgical intervention has been recommended for a proportion of these cases, and this has been made possible as a result of the chemotherapeutic measures employed.
B.53 and B.283 By M. L. CONALTY Laboratories, Medical Research Council of Ireland
that B.53 in a concentration of z/4oo is bactericidal for H37 Rv in a quarter to one hour in the presence of 289 per cent serum. I f the serum concentration is increased to 5 per cent no bactericidal action is noted within twelve hours. We have observed that the growth of gram-negative organisms, B. typhosus, B. toll, B. proteus and B. pyocyaneus, was not B.53 B.53 is the sodium salt of the mixed isomeric inhibited by B.53 at a concentration of monoethyl esters of a-methyl-cx'-n-dodecyl 2,o0o micrograms per millilitre in nutrient horseflesh broth over three days. Gramsuccinic acid [3]. It completely inhibits [3, 4] the growth of positive organisms are inhibited by lower M. tuberculosis H 37 Rv for six weeks at a concentrations of B.53 under the same condilution of 2oo,ooo-4oo,ooo in nutrient ditions but there is a strong antagonism by horseflesh broth but this activity is reduced scrum. C. diphtheriae mills is inhibited at a to IO,OOOin the presence of 5 per cent pooled concentration of IO tLg.]mil, btit in the presence of serum 2oo tLg./mil, is necessary. human serum. Conalty and Chambers have found [5] Inhibitory figures for other organisms are:
Recently [z, 2] increased attention has been paid to two new substances of value in tile chemotherapy of'tuberculosis. These substances which have the code names B.53 and B.283 have been developed in Dublin by a Medical Research Council of Ireland team under the leadership ofV. C. Barry, D.Sc.
256
Domiciliary Treatment of Pulmonary Tuberculosis with Combined Chemotherapy By DAVID L. PUGH Chest Physician, Mid-Kent Area, South-East Metropolitan Regional Hospital Board, at the Chest Clinic, Maidstone Honorary Clinical Assistant, Brompton Hospital. E. R. JONES
Consultant Pathologist, South-East Metropolitan Regional Hospital Board, at the Kent County Laboratory, Maidstone With Approval of the Statistical Evidence by W. J. MARTIN From the Medical Research Council's Statistical Research Unit, London School of Hygiene and Tropical Medicine TABLE I In a recent communication [i] on the PAS and assessment of Sodium PAS as a domiciliary Sodium PAS and thiosemi- Triple measure in the treatment o f a d u h puhnonary Group PAS slreplono'cbz carbazone combined tuberculosis, we put forward the concept that A 27 z6 lo 4 no one agent could be considered to be a B 9 2 4 z panacea for the treatment of tuberculous lesions; rather it is necessary for a planned Total 36 x8 x4 5 combined operation of various methods, making adjustments as and when necessary R e g i m e n o f Treatment to meet the different manifestations of the Three drugs were used in this investigation disease. Under such a system, combined as shown on Table I; 36 cases were given chemotherapy has, we believe, a definite and sodium PAS alone, 18 sodium PAS and valuable place, and its use is justified as a streptomycin and 14 PAS and thic/semitherapeutic and preventive measure. To carbazone (TBI/698) and 5 the triple comthat end we have extended our regimen of bination of sodium PAS, streptomycin and treatment and. accordingly our observations TB I/698. include various combinations of the drugs These drugs were given as follows: available and the findings obtained form the basis of this report. (i) Sodium P A S . - T h e dosage consisted The patients were classified into two of x2 grammes daily for a period of twelve groups according to the type of lesion- weeks, given in cachet form (prepared by Group A, of chronic exudative lesions with Herts Pharmaceuticals Limited) in four or without cavitation and Group B, consist- doses of 3 grammes each. This was combined ing of cases already receiving some form of with x rag. vit. BI daily throughout tile collapse therapy who have been given course, prolonged administration of sodium chemotherapy as a supporting measure. PAS tending to produce a vit. B deficiency. The patients in each of the tWO groups 9 Mist. pot. cit. 89fluid ounce three times daily have been divided into four series dependent after meals was also given during the last on the method of treatment adopted as two weeks of the course in the belief that shown in Table I. such alkalinization of the urine might It will be observed that each series may prevent albuminuria and haematuria. With thus be compared with each of the other this method the toxic effects to which refertreated series. In each series the type of ence was made in our previous comnmnicalesion is similar. tion [2] occurred infrequently and consisted
December
1951
T U BERC LE
of mild gastro-intcstinai upset during the first three weeks of treatment. This was controlled by Benadxs, l given as 5o mg. capsules b.d. in most cases and in those not responding quickly to this treatment the dosage was reduced to one-half with a gradual increase in amount each day, until the normal dosage was obtained. (2) Sodium PAS and Streptono'cin. - Sodium PAS was given in the dosage mentioned above, and continued for a period of sixteen ~,vecks. Strcptomycin was givcn as DihydroStrcptomycin Sulphate ( G l a x o ) i n a daily dosagc of i grammc intramuscularly for thc first six wccks and the last six wccks of thc coursc, sodium PAS bcing givcn alonc for thc intcrvcning four w c c ~ ' pcriod. (3) Sodium PAS and ~ Thiosemicarbazone ( T B z / 6 9 8 ) . - S o d i u m PAS was given as above for a period of twenty-six weeks. rI"hiosemicarbazone (Herts Pharmaceuticals Limited) was commenced at the same-time as PAS and in the following dosage, 5 ~ mg. daily for the first week, zoo mg. for the second week, 15o mg. for the third week, and 2oo rag. for the following twenty-three weeks of the course subject to laboratory investigation to which reference will be made below. (4) Sodium PAS, Streptomycin and TB1]698 (triple combined therapy). - The dosage for the three drugs was that set out above, the treatment being continued for sixteen weeks. Toxk side-effects of thc thrcc drugs conccrncd arc varicd and in some cascs of scrious import to thc paticnt. In thc PAS scrics, onc paticnt in Group A and thrce i n Group B had gastro-int.estinal upsets which responded to treatment. In addition, one patient in Group A demonstrated a confusional state in the twelfth week of the course. In the PAS and streptomycin series, one patient in Group A and one in Group B showed gastro-intestinal symptoms which responded to the regimen described above.
257
One patient in Group A also had vertigo but this disappeared oxl reduction of the streptomycin to o. 5 grannne daily for three weeks and did not return when the dose was subsequently raised to I.O gramme daily. In the PAS and TBx ]698 series, 3 patients in Group A showed toxic changes suggestive of liver damage as revealed b y a positive serum colloidal gold reaction. One of these patients was unable to complete the full course of TBz]698 and was given PAS alone. I11 addition, I patient in Group A and I in Group B had mild gastro-intestinal disturbance. In the triple combined series, one patient in Group A showed hallucinations and vertigo with deafness late in the course. These symptoms disappeared when the antibiotic was withhelcl though the PAS was continued. A report on this case showed that the patient was suffering from streptomycin 'drunkenness', resulting from a degeneration of the vestibular section of the eighth cranial nerve, with some associated involvement of the basal turn of the cochlea. In this series also, one patient in Group B showed a mild gastro-intestinal disturbance and the same patient showed an allergic response to thiosemicarbazone, revealed by the presence of a papular eruption with conjunctivitis. This condition responded to a reduction of the dosage from 2oo mg. daily to zoo mg. daily for three weeks and did not return 'when the dose was increased by the usual stages to the 2oo mg., which dosage was maintained until the end of the course with no recrudescence of symptoms. The results of the clinical, radiological and laboratory investigations may now be reviewed. Combined Clinical and Radiological Assessment
Table II gives the results obtained from an assessment of the combined clinical and radiological findings, the former being based on the weight changes, the erythrocyte sedimentation rate (Westergren) and the
258
T U BERC L E
December 1951
TABLE II.--CLINICAL AND R A D I O L O G I C A L ASSESSMENT PAS and PAS and Triple PAS streptono'cin TB I/698 combined NC D T I NC D T I NC D T I NC D T
Group
I
A
i6
9
,2
27
12
4
o
z6
8
2
o
IO
2
2
o
B
6
3
o
9
,2
o
o
~
3
I
o
4
l
o
o
l
Total 22 Percent 6I
i2 32
,2 6
36 ~
o o
z8 ~
zz 79
3 2x
o o
14 3 - - 6o
2 4~
o o
5 --
I4 4 78 ,22
4
I = improved. NC = no change. D = deterioration. T = Total. Assessment based on - l, weight. 2, E.S.R. 3, sputum. 4, x-ray findings. sputum results. These four factors, which were given equal value in the assessment, were chosen so that the errors of subjective vfiluation may be overcome. It will be scen from the table that 2 patients in Group A of the PAS series showed deterioration. In the PAS series, 22 (6z per cent) out of 36 patients were found to be improved and I2 (32 per cent) showed no change. In the PAS and streptomycin series, 14 (78 per c e n t ) o u t of z8 showed improvement and 4 (2,2 per cent) showed no change. In the PAS and thiosemicarbazone series, I I (79 per cent) out of 14 improved while 3 (2I per cent) were unchanged, and in the small triple combined series 3 out of 5 patients improved and 2 showed no change. A more detailed analysis of the contributing factors in this assessment revealed interesting features. Gain in weight was most marked in the PAS and thiosemicarbazone series, tile next best being the PAS and streptomycin series, but tile difference is not statistically significant. The erythrocyte sedimentation rate was reduced to the greatest extent in the PAS and streptomycin series, the only change of significance. Marked changes occurred in the sputum resuhs in all groups. There was a reduction in the number Of patients with a positive sputum after treatment, and a significant rise in the number showing a negative sputum or no sputum. Excluding the small triple combined series this change was largest in the PAS and thiosemicarbazone series, next in the PAS and streptomycin series and next in the PAS series. For allseries the combined
number of patients with positive sputum decreased from 46 (63 per cent) before treatment to 12 (I 6 per cent) after treatment, a statistically significant difference.
Radiological Assessment Table I I I shows the results of this assessment and reveals a marked improvement in all series as the result of t r e a t m e n t ; i n no case was any deterioration found. A radiological improvement in 6o per cent or over of the cases in the type of lesion treated is an indication of the success of the therapeutic regimen adopted, though it would have been more convincing had it been poss!ble to have had larger numbers in some of the series. The figures reveal an improvement in both groups. In the PAS series 28 (78 per cent) out of 36, PAS and streptomycin series t6 (89 per cent) out of I8, PAS and thiosemicarbazone series 13 (93 per cent) out of z4, and triple combined series 3 out of 5 cases showed improvement. Thus tile improvement was most marked in the PAS and thiosemicarbazone and the PAS and streptomycin 9 serics.
Cavitation
Table IV shows the presence of cavitation in patients in each series and in each group before treatment and after treatment. In the PAS series half the number of patients in each group showed cavitation, and in these in approximately 25 per cent cavity closure was obtained. In the PAS and streptomycin series z3 out of I8 patients showed cavitation and in only 2 was there cavity closure. The PAS and thiosemicarbazone series gave a
December 1951
T U BERC L E
259
TABLE I I I - X-RAY ASSESSMENT PAS and PAS and streptomycin thiosemicarbazone T I NC D T I NC D T I
Sodium PAS NC D
Triple combined NC D T
Group
I
A B
"20 8
7 1
o o
27 9
14 2
2 o
o o
16 2
9 4
z o
o o
1o 4
,, z
2 o
o o
4 1
28 78
8 22
o o
36 --
z6 89
2 I1
o o
z8 --
13 93
1
o o
14 --
3 6o
2 4~
o o
5
7
Total Per cent
I = improved. NC = no change. D = deteriorated. T = Total. *I'ABLE IV - CAVITATION
Series Groups Total .... Cavity present .. Cavity closure 99 Cavity persisting ..
Sodium PAS A B T
PAS and streptomycin A B T
27 I3 3
9 4 3
36 x7 6
i6 ix 2
2 2 o
18 x3 2
io 9 4
4 i o
x4 IO 4
4 4 o
x z I
5 5 I
zo
I
Iz
9
2
I
5
I
6
4
o
4
b e t t e r result in that 4 ~ p e r cent showed cavity closure, while in the triple c o m b i n e d series the cavity was closed in I case in 5. T h e r e was a close a p p r o x i m a t i o n o f the p e r c e n t a g e i m p r o v e m e n t shown in all series, the best results being o b t a i n e d with the combinations o f PAS with streptomycin and PAS a n d thiosemicarbazone. T h e observations confirmed the desirability o f c o m b i n e d c h e m o t h e r a p y in the t r e a t m e n t o f p u l m o n a r y tuberculous lesions. Laboratory
Investigations
In addition to s p u t u m examinations for tubercle bacilli, certain o t h e r l a b o r a t o r y investigations were carried out during this investigation. These i n c l u d e d culture o f tubercle bacilli with special reference to t h e d e v e l o p m e n t o f bacillary resistance to the drugs employed, and, in the case of those patients receiving T B I / 6 9 8 , liver function tests in view o f the possibility o f liver d a m a g e developing as reported b y the G e r m a n clinicians.
Haematology A total c o u n t o f red cells a n d leucocytes, a differential c o u n t and a h a e m o g l o b i n estimation were m a d e on three occasions on all patients receiving PAS a n d PAS plus streptomycin, one i m m e d i a t e l y before the
PAS and thiosemicarbazone combined A B T A B T
c o m m e n c e m e n t o f treatment, one n e a r the
middle o f the course and the third within a d a y or two o f completing the course. I n the" case o f patients receiving thiosemicarbazonethe above blood examinations were m a d e at: m o n t h l y intervals with leucocyte and differential counts, haemoglobin estimation a n d m e a n corpuscular haemoglobin concentration on each o f the intervening weeks. Tile more f r e q u e n t tests on thiosemicarbazone patients were m a d e because cases o f h a e m o lyric a n a e m i a and agranulocytosis had been r e p o r t e d by G e r m a n workers, a n d we had no previous experience o f the use o f this drug. With the dosage of thiosemicarbazone used, no cases o f agranulocytosis or of severe haemolysis, due to the possible liberation o f p h e n y l h y d r a z i n e as a b r e a k d o w n p r o d u c t o f the thiosemicarbazone, were encountered d u r i n g this investigation.
Culture and Development to Drugs
of
Resistance
Specimens o f s p u t u m were obtained whenever available d u r i n g the course o f t r e a t m e n t for microscopic and cultural examination, a n d w h e n positive p r i m a r y cuhures were obtained, the sensitivity o f the organisms to the various drugs were tested by the m e t h o d described previously [2]. Sensitivity to PAS
260
T U B ERC L E
was dctcrmined on Lowenstein's nacdium containing varying concentrations of PAS. This medium proved unsatisfactory for the determination of streptomycin sensitivity and Herrold's egg-yolk agar gave better results. Both these solid media were found unsuitable for TBI/698 sensitivity tests and Dubos' fluid media was used. On these media and using the technique described (loc. cit.) normal tubercle bacilli, isolated from patients who had not received any of the drugs, were found to be sensitive to o.~ 5 rag. and resistant to o.o25 mg. PAS per IOO ml. medium, sensitive to 5 units and resistant to i unit streptomycin per ml. medium, sensitive to o.I and resistant to o.oi ing. TBI/698 per IOO ml. medium. Many of the patients had no sputum shortly after commencing treatment, others were microscopically and culturally negative throughout, and from some on combined therapy specimens were not always available during the period when the patients happened to be on two or more drugs at tile same time. In 4 cases microscopic examination was positive but the organism failed to grow on an artificial medium, and from a fifth patient, one specimen was microscopically positive and culturally negative, whereas previous specimens were positive both microscopically and on culture. In all these specimens, microscopic examination revealed mainly morphologically degenerate forms of bacilli. In a previous investigation on the development of strains of tubercle bacilli resistant to PAS [2] it was stated that over the limited period during which the cases had been followed, the indications were that once resistant strains had developed, the change in the nature of the organisms was permanent. A m o r e extended follow-up of these cases showed that this was not ahvays the case. After an interval of three to five months without PAS, the resistance of the tubercle bacilli retttrned more or less to their original level, but increased when the patients were put on PAS again.
December 1951
In the same investigation it was stated that 5 cases where tubcrcle bacilli resistant to 6"4 rag. PAS per IOO ml. were given a further course of PAS since the patients were to have a course of streptomycin in the hope that the PAS might prevent the development of strains resistant to streptomycin. It has been found, however, that PAS does not prevent the development of streptomycin-resist ant strains. It is not possible to give a simple classification of the results obtained from our sensitivity tests, but the following general statements may be made: (I) In most, but not all, cases after prolonged use (up to six months) the tubercle bacilli develop a resistance to PAS greater than tile average therapeutic level obtainable in the serum of the patient. (2) PAS used in conjunction with streptomycin or TBI/698 does not prevent the development of resistance to the latter chemotherapeutic agents, nor is the resistance of the bacilli to PAS influenced by the simultaneous administration of streptomycin or TBI/698. (3) O f the 4 cases in which resistance tests to PAS and TBI/698 could be carried out, one developed a strain resistant to o.I rag. and sensitive to I mg. per cent TBr/698; jn the other 3 cases, when examined, the organisms were of normal resistance. Liver Function Tests
The liver function tests carried out weekly on all patients on TBI/698 were albumin and globulin estimations, serum colloidal gold tests, alkaline phosphatase estimations, and bilirubin determinations when considered necessary. The serum of these patients has a greenish-yellow tinge and several quantitative van den Bergh tests were carried out, but in no case was the bilirubin content increased above the normal. The serum colloidal gold reaction is a sensitive indicator of active hepatic disease and a strongly positive reaction is considered to be almost diagnostic of parenchymatous
December 1951
TUBERCLE
261
O f the x8 patients in.the PAS and streptodisease. Hence cases who had more than a I + colloidal gold before treatment were not mycin series, 2 had an existing thoracoplasty put on TBI/698 except in one case who had and 3 were recommended for this operation. a 3-t- reaction. After five weeks' treatment, 4 patients were given a further course of this patient's serum colloidal gold reaction chemotherapy, 3 being given PAS and was 5 + and further treatment with TBI/698 streptomycin and x being given PAS and thiosemicarbazone. The remainder had no was discontinued. Two cases showed a 2 + further form of active treatment. and 5 a I + reaction during treatment. O f the 14 patients in the PAS and thioA raised serum alkaline phosphatase is found in various types of liver damage in- semicarbazone series, 2 patients had an A.P. cluding tuberculosis. None of the patients in maintained, 2 had an A.P. abandoned, 2 the series had a phosphatase level above 13 were recommended for thoracoplasty and units, the upper limit of normal, before the one for PAS and streptomycin. The remaincommencement of treatment. During treat- der had no further form of active treatment. In the small triple combined series of 5 ment, there were marked weekly variations, some rising slightly above 13 units, and then patients, i had an A.P. maintained and the falling except in one case where the level same patient had a collapse of the other rose steadily to 37 units, but even in this lung by means o f a n osteoplastic pneumolysis, case, there w a s no clinical evidence of and one patient was given a course of PAS and thiosemicarbazone. The remainder had increasing liver damage. Before treatment 12 of the 19 patients no further form of active treatment. In no case were the results of this Second had an albumin-globulin ratio of less than course of chemotherapy included in this I to I, but after treatment the ratio was report even though the combination differed greater than x to I in 15 of the 19 patients, from thai of the original course. thus confirming the findings of previous workers that Till/698 tends to reverse the Discussion albumin-globulin ratio in the direction of The problem of the evaluation of any drug normal. or combination of drugs in the treatment of As all these TBI/698 patients were having pulmonary tuberculosis is difficult and it is either PAS or streptomycin as well, it is not only after a considerable time has elapsed possible to assess how much these changes that it may be possible to make a conclusive were due to the TBI/698 alone. statement that might be of scientific value. It is, however, established that chemotherapy C o n t i n u a t i o n of T r e a t m e n t is an effective means of treating pulmonary At the end of the course of treatment the tuberculosis under certain conditions, though patients in each series were kept under it is only one method; all other proved observation and close surveillance and were methods continue [o be necessary and cannot divided into three sub-sections-those re- be discarded at the present time. As the quiting no further active treatment, those report of the clinical sub-committee of requiring further chemotherapy and t h o s e Antimicrobial Therapy in Tuberculosis of requiring some other form of treatment. the American Trudeau Society [3] states: In the PAS series, of the 3 6 patients, one 'the administration of antimicrobial ~/gents had an existing A.P. continued and one should be carefully correlated with an overalready had a thoracoplasty. 3 patients had all programme of medical and surgical their A.P. abandoned, 5 were recommended treatment. The emergence of drug-resistant for thoracoplasty, and 3 were given a further strains of the tubercle bacilli may be delayed course of chemotherapy, PAS and strepto- by the simultaneous administration of certain mycin. The remainder had no further form combinations of antimicroblals and the best combination available today is one of of active treatment.
262
T U B ERC L E
the streptomycin drugs together with some form of PAS.' The report advocates this treatment being undertaken in hospital, but Westergren [4] has stated that 'in favourable circumstances such treatment may be conducted outside hospital' with the proviso that only doctors with experience in this field should plan and observe the effects of chemotherapy in tuberculosis. Heilmeyer [5] believes that while permanent cure with chemotherapy alone may be obtained in cases free from cavities, the majority of cavitating lesions require some form of surgery for their elimination. Lesions of recent origin respond better than those of long duration and it may be that these lesions show improvement on conservative measures alone. Chemotherapy, however, reduces the time factor in such lesions by producing stabilization much earlier. Furthermore, it is unwise to withhold a proven regimen of treatment in the interest of conservatism if there is reason to fear that progressive disease is likely to develop. Chemotherapy is also of value in" supporting existing collapse therapy and may be used as an 'umbrella' to cover the abandonment of collapse therapy rendered necessary by spontaneous obliteration of the pleural space or the evidence of a frozen hmg. The present review demonstrates clearly the value of domiciliary combined chemotherapy in exudative lesions and as a support for existing collapse therapy. The present results reveal marked improvement in all tile series of cases by clinical, radiological and laboratory findings. Each case has been initially reviewed in the light of a 'planned combined operation' of treatment, in which bed-rest and chemotherapy at home have formed the first and early stages, progressing where necessary to active surgical intervention. Success is not claimed in all cases, but there is to be found in the data ample justification for the procedure adoptcd. In an 'over-all' review of the series, we believe that the combinations of PAS and streptomycin and PAS and thiosemicar-
December 1951
bazone are the most effective. The results of the latter series have been more favourable than we anticipated at the outset, while the triple combined series, included as a matter of interest, is too small for statistical significance. Toxic effects due to the drugs used have been negligible, only one severe case of neurotoxicity to streptomycin and only one case of hepatic damage possibly due to thiosemicarbazone having occurred. VCe have observed, however, the onset of a manic-depressive type of syndrome in 2 of the cases in the series and in x other not included owing to his admission to hospital for the further treatment of his tuberculous lesion. In all these cases, PAS has formed the basis of treatment and we do not believe that the symptoms are attributable to the salicylic radicle; rather is it a confusional state arising as a delayed reaction at the end of a twelve weeks' course of treatment or when tile stress of a return to take up a normal position in the economic world proves to be too great. One further theory may be added. The work of Hetzel and Hine [6] postulates that the therapeutic effects of salicylates occur by virtue of their stimulation of the pituitary and suprarenal glands. This concept finds no support from the experiments of Meade and Smith [7]. If, however, this theory is proven then it may well be that the prolonged stimulation of these glands by Na PAS therapy may cause a decrease in their secretion due to over-stimulation with the production of hypocorticoidism. This condition may, according to Selye [8], give rise to mental symptoms such as sudden psychic disturbances including acute spells of maniac excitement, in which the ability of concentration and thinking is impaired. Whether the syndrome is connected with stimulation of the pituitary gland by the PAS, or with the hypopotassaemia which may accompany the treatment, or is a toxic confusional state, are matters for further investigation. Cavitating lesions have not responded as a general rule, the number of cases in which there has been cavity closure being limited.
December 1951
T U BERC L E
263
Resistant strains of the tubercle bacillus have developed and the use of PAS in conjunction with streptomycin and thiosemicarbazone does not prevent the development of resistance to the latter agents. The change Summary in nature of the organisms in response to The domiciliary use of combinations of PAS therapy is not always permanent. chemotherapeutic agents in the treatment Our thanks are due to the members of the of pulmonary tuberculosis is reviewed. staffs of the Maidstone Chest Clinic, and the The majority of patients in all series Kent County Laboratory, and the Pharmashowed improvement by clinical, radiologieal cist of the West Kent General Hospital for and laboratory findings. their continued assistance. The regimen of treatment adopted formed part of a 'planned combined operation'. References Fhe combinations of PAS with strepto- [I] Pugh, D. L.,Jones, E. R., and Martin, W . j . (195o) Lancet, II, 92. mycin and PAS with thiosemicarbazone [2] Pugh, D. L., Jones, E. R., and Martin, W.J. (x95z) were found to be most effective, the latter Tubercle, xxxH (3), 5 ~ Trudeau Society (z95 Q American Review of being more favourable than originally [3] American Tuberculosis,/_xm, 5, 6z7. [4] Westergren, A. (195o) Word. Med., x/-m, 4o3 . anticipated. [5] lleilmeyer, L. 095 o) LM.H;, eL, 75, 473. Toxic side-effects have been negligible. [6] Itetzel, B. S., and Iline, D. C. (195 l) Lancet, u, 94. Cavitating lesions have not shown a good [7] Meade, B. W., and Smith, M. J. II. (195 Q Lancet, Letters to the Editor, n, 224. response but surgical intervention had been [8] Selye, H. (x949) Textbook of Endocrinology. made possible as a result of chemotherapy. Montreal, Ed. n, 147.
Surgical intervention has been recommended for a proportion of these cases, and this has been made possible as a result of the chemotherapeutic measures employed.
B.53 and B.283 By M. L. CONALTY Laboratories, Medical Research Council of Ireland
that B.53 in a concentration of z/4oo is bactericidal for H37 Rv in a quarter to one hour in the presence of 289 per cent serum. I f the serum concentration is increased to 5 per cent no bactericidal action is noted within twelve hours. We have observed that the growth of gram-negative organisms, B. typhosus, B. toll, B. proteus and B. pyocyaneus, was not B.53 B.53 is the sodium salt of the mixed isomeric inhibited by B.53 at a concentration of monoethyl esters of a-methyl-cx'-n-dodecyl 2,o0o micrograms per millilitre in nutrient horseflesh broth over three days. Gramsuccinic acid [3]. It completely inhibits [3, 4] the growth of positive organisms are inhibited by lower M. tuberculosis H 37 Rv for six weeks at a concentrations of B.53 under the same condilution of 2oo,ooo-4oo,ooo in nutrient ditions but there is a strong antagonism by horseflesh broth but this activity is reduced scrum. C. diphtheriae mills is inhibited at a to IO,OOOin the presence of 5 per cent pooled concentration of IO tLg.]mil, btit in the presence of serum 2oo tLg./mil, is necessary. human serum. Conalty and Chambers have found [5] Inhibitory figures for other organisms are:
Recently [z, 2] increased attention has been paid to two new substances of value in tile chemotherapy of'tuberculosis. These substances which have the code names B.53 and B.283 have been developed in Dublin by a Medical Research Council of Ireland team under the leadership ofV. C. Barry, D.Sc.