Abortions in early pregnancy and recurrent miscarriages

781

Biomed. & Pharmacother., 43 (1989) 781-784 8 Elsevier, Paris

Neurofibromatosis-2. Neurofibromatosis-2 (formerly known as “central” or “bilateral acoustic neurofibromatosis”) is characterized by the emergence of multiple nerve sheath tumors (meningiomas, acoustic neuromas, gliomas, ependymomas) and lack of skin signs typical of NF-1 (“cafe au lait” spots, neurotibromas, pheochromocytoma, etc.). Patients with multiple nerve sheath tumors or with similarly affected relatives are suspect NF-2, and autosomal dominant disorder of probably nearly complete penetrance. Presymptomatic diagnosis of NF-2 poses difficulties and is based on cranial and spinal CT and MRI studies. Besides tumoral signs, non-tumoral calcifications in unusual areas of the choroid plexus, away from the glomus, or in unusual configurations on the falx may be a prodromic sign. Simultaneous use of D22Sl and IGLV DNA markers to study coinheritance of NF-2 in 22 patients and unaffected relatives from a large kindred indicated that the locus for the disease in near the long arm ofchromosome 22 (22qll.l-22q13.1). None of the 22 patients met the diagnostic criteria of NF-1. W. Wertelecki (1) University of South Alabama, Mobile AL 36688, USA

Renal impairment in hyperteasive patients. Thirty-four patients with mild-to-moderate essential hypertension and apparently normal renal function and 22 healthy controls were submitted to an amino acid infusion to test the ability of their kidney to increase glomerular filtration rate. While in all controls basal creatinine clearance increased after amino acid infusion (mean 27.9 ml/min, CI : l&2--37.6), in hypertensive Patients the overall change was lower (mean 13.4 ml/min, CI : 8.3-18.5) and in 11 out 34 (32.3 %) patients there was no increase at all. In the group of non-responder patients, systolic blood pressure was higher (mean 23.73 kPa) (178.5 mm Hg) than in the responders (mean 20.93 kPa) (157 mm Hg). Mean urinary albumin excretion was abnormal in hypertensive patients (mean 93.3 mg/24 h, CI : 44.2-142.4); in particular, 8 out 11 non-responders had an albumin excretion above the normal range (> 20 mg/24 h). In these patients without renal functional reserve a positive correlation (r-0.695)between basal creatinine clearance and albumin excretion was found. Since consumed renal reserve and albuminuria are markers of glomerular hyperliltration, we conclude that the study of renal function before and after amino acid

infusion helps in singling out hypertlltering hypertensive patients that are at risk of progressive renal damage. A. Losito (2) Poiiclinico, Servizio di Nefrologia e Dialisi 06100 Perugia, Italy

Double-stranded tioa.

DNA transfer during reverse transcrip-

Retroviruses are RNA-containing viruses that replicate through a DNA intermediate in a wide variety of vertebrate hosts including man. Human pathogens include HIV-l and 2 which cause AIDS and HTLV-I and II which cause T-cell leukemia. Each retrovirus contains two copies of the plus-stranded RNA genome which, following infection, are used in the formation of viral DNA by the process of reverse transcription. However, since each individual molecule contains sufficient genetic information for the generation of a DNA copy, the presence of two RNA molecules in the virus is enigmatic. To investigate the role of the two RNA molecules in the formation of the viral DNA, heterozygous virion particles were generated that contained distinguishable nucleic acid sequences at the ends of the viral RNA The fate of these genetic markers was then followed by characterization of the viral DNA that resulted from reverse transcription. These DNAs all contained a distinctive pattern of terminal nucleic acid markers indicating that both RNAs of the virus contribute to the genetic makeup of the DNA copy. Reverse transcription begins by using one RNA template and then is continued using the other RNA in a precise manner. An implication of this pattern of nucleic acid replication is that situations that give rise to heterozygous virion particles, such as the infection of a single cell by two different virus types, would be expected to yield recombinants at high efficiency. Such recombinants might then possess new biological properties. A. Panganiban (3) University of Wisconsin, Madison, WI 53706, USA

Abortions in early pregnancy and recurreat miscarriages. It has been proposed that unexplained recurrent miscarriages are caused by maternal immune rejection of the genetically foreign fetus. This presumed problem has been treated by immunisation with paternal leuco(2) Br. Med. J. (1988) 296, 1562.

(1) N. Engl. J. Med. (1988) 319, 278.

(3) Science (1988) 241, 1064.

782 cytes, the beneficial effect being attributed to the induction of maternal anti-paternal antibodies that block this rejection response. However, there is no direct evidence that immune rejection occurs, SO that the rationale for immunotherapy is, at best, based on circumstance. We have therefore measured maternal cell-mediated immunity to fetal (paternal) antigens, maternal cytotoxic alloantibody production and the blocking effect of maternal sera on maternal lymphocyte activation, before conception, in early pregnancy and at the time of miscarriage. The results provide evidence that cell-mediated immunity may be changed in some women who abort recurrently but show that circulating immunological blocking factors are not relevant to the success of pregnancy. Their induction by maternal immunisation with paternal leucocytes does not explain why this procedure prevents recurrent spontaneous abortions. LL. Bargent(1) John Radcliff Hospital, Oxford OK3 9DU, UK Cytoruega!ovJrusInfection. CMV infections in kidney transplant recipients require a rapid diagnosis since they can be life-threatening. In this context, detection of granulocyte-associated immunoglobulins was compared to conventional virological methods for diagnosis of CMV infection in 71 kidney transplant recipients. The granulocyte-associated immunoglobulin test was found positive in 31 out of 34 patients with proven CMV mfections on the day of admission. On the basis of conventional virological criteria the diagnosis of active CMV infection could be ascertained only 3-24 days later. On the contrary, GAIT remained negative in 14 healthy transplant, recipients. However, it was positive in 9 of 23 patients with non-CMV related post-transplantation complications. In such cases, however, immunoglobulins were also found either on red cells or on platelets and GAIT positivity could be related to the presence of antibiotics or anti-lymphocytes globulins immuniza. tion. The granuiocyte-associated immunoglobulin test, which is not a virilogicai Imethod, can be a useful’tool for rapid diagnosis of CMV infection since its sensitiv. ity and specificity are respectively 0.91 and 0.82 and its processing time is 3 hours.

implementation of cross-infection control measures can prevent spread of the yeast and thereby save lives. Several different typing systems have been developed for C. albicans, but these have had to be used in combination to achieve sufficient reproducibility and discrimination to reliably identify an outbreak. DNA fingerprinting was found to be a major advance in typing C. albicans, as it provided a means by which outbreaks could be reliably identified in a matter of a few days. Four out of 5 outbreaks were identified by DNA fingerprinting alone, without the need to use it in combination with other typing systems. R. Matthews(3) St. Bartholomew’sHospital, London EC 1A 7BE, UK

Methicillin resistance strains of Stap~~ylococcusaureus were recognized almost immediately aftL.7the introduction of methtcihin (i961). However, they occurred only sporadically and caused no particular problems. In contrast, strains resistant to methiciilin and aminoglycosides - which are the subject of this review appeared only some 10 years ago, and have been a constant source of trouble in hospitals all over the world. They are virulent and highly multi-resistant, the only generally available antibiotics active against them being vancomycin and teicoplanin. The review summarizes resistance patterns and mechanisms, the detection and the epidemiology of such strains. Particular attention is paid to the various control measures used, which need to be codified and field-tested, and the review ends by reminding readers that preventian is better than cure. J.M.T. Hamilton-Miller (4) The Royal Free Hospital, London NW3 2QG, UK Cerebral malaria.

Systemic candidiasis has a high mortality of over 70 %. Outbreaks due to cross-infection with a single strain of COndid a&ans were first described in 1985. Prompt

Cerebral malaria is the commonest form of severe Fulciparum malaria. The patient loses consciousness and suffers from generalised convulsions and may develop a variety of neurological signs. About 20 % of patients with cerebral malaria die of the disease. Ignorance of the underlying mechanism of cerebral disturbances has been a major obstacle to improving treatment. Currently, the most compelling explanation for cerebral malaria is that erythrocytes containing immature forms of Plasmodiumfakiparum stick to the walls of cerebral venules, producing an obstruction to blood flow and hence reducing the supply of oxygen and other important nutrients to the brain. Cytoadherence of parasitised erythrocytes leads to their sequestration in cerebral blood vessels. Predicted physiological

(1) Lam-et(1988) ii, 1099. (2) Lancet (1988) ii, 1338.

(3) Br. Med. J. (1989) 298, 354. (4) Lancet (1989) i, 537.

H. Kreiss (2) HGpitalNecker, 75015 Paris, France DNA lingerprinting

in systemic candidiasis.