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The clinical significance of serum triiodothyronine assay
A B S T R A C T S O F A N N U A L M E E T I N G 1974
65
FURTHER STUDIES OF THE MAJOR LIPOPROTEINS MADE POSSIBLE BY THE ADSORPTION TO MAGNESIUM COMPOUNDS TRAILL, M. A. Royal Park Psychiatric Hospital, Parkville, Victoria The adsorption techniques for removing the 8-lipoprotein and both the a-lipoprotein and the 8-lipoprotein from sera have been examined. New findings include:
1. A prep-lipoprotein: 8-lipoprotein cholesterol ratio greater than 0.4 in the Frederickson types 111, IV and V; 2. A good correlation between the cholesterol and the triglyceride in the prep-lipoprotein and a poor correlation in the 8-lipoprotein; 3. The characteristics of a ‘midp-lipoprotein’ which moves between the ,%lipoprotein and the preplipoprotein during electrophoresis in agar. It is not adsorbed by light magnesium carbonate yet is adsorbed by the mixture of light magnesium carbonate and magnesium trisilicate, can be found in normal sera, appears increased in Frederickson’s type I I b phenotype, apparently still has a-lipoprotein antigenic determinants, and seems to bind very little cholesterol; 4. Estimations for corrections that may be applied to allow for the a-lipoprotein cholesterol that is removed by the adsorption with light magnesium carbonate. Approximately 38-4014 of the alipoprotein cholesterol is removed, yet the carrier protein appears relatively resistant to adsorption even by the magnesium carbonate and trisilicate. The removal of a-lipoprotein cholesterol causes the 8-lipoprotein cholesterol to be read too high unless corrections are applied. PARAN 01A, LY M PH 0 EDEMA, MACROG LO BU LI NAEM IA AN D LYMPHOCYTOPENIA: WHIPPLE’S LIPODYSTROPHY IN DISGUISE TRAILL, M. A. Mont Park Pathology Centre, Victoria
A man of 64, thin, ill-nourished and hallucinated, had oedema of the legs and some skin cancers. He later developed recurrent cellulitis of the legs, numerous skin cancers which were excised, and his mental status cleared. At the age of 74, when presenting with another attack of cellulitis it was noted that he had virtually no lymphocytes in the peripheral blood, a macroglobulinaemia with the IgM greater than 1Og/l and lymphoedema of the legs. Bone marrow examination revealed 10-20% plasma cells. Three years later he died of cardiac failure and bronchopneumonia. At autopsy the small bowel had a grossly thickened and yellow submucosa, the muscle being thin and brown. Lymph nodes could not be located macrascopically. Microscopically the bowel had masses of lipid-laden macrophages resembling those found in Whipple’s disease; occasional ones were PAS-positive. The tissues about the major lymphatic ducts appeared fibrotic. The bone marrow had no evidence of any infiltration. The patient appears to have had Whipple’s disease of long standing, held in partial remission and modified by the courses of antibiotic therapy used for cellulitis in his legs, the latter no doubt predisposed by the sclerosis of the lymphatic system due to the underlying disease. THE CLINICAL SIGNIFICANCE OF SERUM TRIIODOTHYRONINE ASSAY WELLBY, M. L., KANAGASABAPATHY, A. S., GRAYCAR, LINDSAY E. and MARSHALL,JANETM. Departmmt of Clinical Chemistry, The Queen Elizabeth Hospital, Woodville, South Australia Triiodothyronine (T,)normally contributes about 70% of the total metabolic activity of the thyroid hormones in man. There are certain situations where this percentage is greatly exceeded and where the assay of serum total T, concentration is more important than the assay of total thyroxine (TJ. Radioimmunoassay (RIA) on unextracted serum samples was used for T, in this study, the mean level for 60 euthyroid normal volunteers being 136 ng/dl and standard deviation 26 (the reference range is 84-188ng/dl). The sensitivityof the assay is 12.5 pg/tube and the ‘between assay’ precision has a coefficient of variation of 8.9y0. The main clinical applications for serum T, were found to be as follows: 1. The diagnosis of the rare primary T, thyrotoxicosis.
66
THE ROYAL COLLEGE OF PATHOLOGISTS OF AUSTRALIA
2. For confirming the thyroid status of thyrotoxic patients previously treated with radioactive iodine (I3lI). Only 64.3””of euthyroid treated thyrotoxicosis patients had total T, in the reference range, whereas the total T, concentration was always in the reference range. 3. In thyrotrophin releasing hormone (RH) ’I stimulation studies. Normally serum T S H responses to T R H suffice but in patients with borderline clinical primary hypothyroidism, studies of serum T, responses were also very useful. In patients with 1311-treated thyrotoxicosis, it was shown that measurement of T:,responses to T R H is as essential as the response in TSH.
LABORATORY MANAGEMENT AND WORKLOAD RECORDING
WILLIAMS,MARJORIE J.
Veterans Adminisrration, Washinston, D.C.
Presented on behalf of rhe College of American Pathologists The College of American Pathologists is concentrating considerable effort in developing methods for measurement of the various components in laboratory management. Among its accomplishments is the development in conjunction with the Canadian Association of Pathologists of a Workload Recording Method for Clinical Laboratories, which is rapidly becoming a standard in North America. The precision of its nomenclature and definitions permit valid measurement while the unit values (weighting factors) add discrimination. Valuable information is accumulating on ranges of productivity for technical-clerical staff in hospitals and independent laboratories. Productivity is generally similar in all hospitals with more than 50 beds and the median approximates 45 unit values/paid man-hour in general hospitals. Productivity tends to be somewhat higher in independent laboratories with their more circumscribed operations. The continuing value of the Workload Recording Method is now assured with the establishment of procedures for self-renewal. A ‘universal’ protocol is availabk for collection of data for timing studies with centralized computer analysis support. New timing studies are accepted only after joint agreement on their validity. The Workload Recording Method through measurement of productivity can identify staffing requirements and, since salaries are major laboratory costs, the unit values become important in cost-finding procedures. Standard cost-finding techniques using the Workload Recording Method are now in preparation by the College and will be followed by the development of charts of accounts and publication of a manual.
SEQUENTIAL PATHOLOGICAL CHANGES SEEN I N CONTROLLED TRAUMA TO THE SPINAL CORD OF THE SHEEP
YEO,J. D. and PAYNE,W. H. Spinal Znjurizs Unit and Department of Clinical Pathology, The Royal North Shore Hospital of Sydney
Many patients with spinal cord damage suffer permanent paralysis and loss of sensation although the cord was severely bruised rather than lacerated by the displacement of the vertebral column. Experimental work has suggested that this apparently irreversible injury may be caused by ischaemia and could be at least partly reversed by the early introduction of physical or chemical treatment. In our experiment a controlled contusion injury is inflicted on the spinal cord of sheep. This shows swelling of the cord caused by congestion, haemorrhage and swollen axons and myelin sheaths. Between 2 and 4 h after the injury, breakdown and coalescence of myelin sheaths is the earliest structural evidence of permanent damage to the cord. When isotope rather than contrast myelography is used there is usually only partial obstruction to the flow of CSF so that the cord swelling alone is probably not responsible for the ischaemia. A local noradrenalin effect was suspected and a catecholamine antagonist injected within 1 h of the injury some reduction of the functional deficit and the size of the central cystic lesion in the cord was achieved. Further experiments are planned to measure the effect of alpha-methyl paratyrosine (a catecholamine antagonist) on the levels of noradrenalin in the blood and spinal cord.
65
FURTHER STUDIES OF THE MAJOR LIPOPROTEINS MADE POSSIBLE BY THE ADSORPTION TO MAGNESIUM COMPOUNDS TRAILL, M. A. Royal Park Psychiatric Hospital, Parkville, Victoria The adsorption techniques for removing the 8-lipoprotein and both the a-lipoprotein and the 8-lipoprotein from sera have been examined. New findings include:
1. A prep-lipoprotein: 8-lipoprotein cholesterol ratio greater than 0.4 in the Frederickson types 111, IV and V; 2. A good correlation between the cholesterol and the triglyceride in the prep-lipoprotein and a poor correlation in the 8-lipoprotein; 3. The characteristics of a ‘midp-lipoprotein’ which moves between the ,%lipoprotein and the preplipoprotein during electrophoresis in agar. It is not adsorbed by light magnesium carbonate yet is adsorbed by the mixture of light magnesium carbonate and magnesium trisilicate, can be found in normal sera, appears increased in Frederickson’s type I I b phenotype, apparently still has a-lipoprotein antigenic determinants, and seems to bind very little cholesterol; 4. Estimations for corrections that may be applied to allow for the a-lipoprotein cholesterol that is removed by the adsorption with light magnesium carbonate. Approximately 38-4014 of the alipoprotein cholesterol is removed, yet the carrier protein appears relatively resistant to adsorption even by the magnesium carbonate and trisilicate. The removal of a-lipoprotein cholesterol causes the 8-lipoprotein cholesterol to be read too high unless corrections are applied. PARAN 01A, LY M PH 0 EDEMA, MACROG LO BU LI NAEM IA AN D LYMPHOCYTOPENIA: WHIPPLE’S LIPODYSTROPHY IN DISGUISE TRAILL, M. A. Mont Park Pathology Centre, Victoria
A man of 64, thin, ill-nourished and hallucinated, had oedema of the legs and some skin cancers. He later developed recurrent cellulitis of the legs, numerous skin cancers which were excised, and his mental status cleared. At the age of 74, when presenting with another attack of cellulitis it was noted that he had virtually no lymphocytes in the peripheral blood, a macroglobulinaemia with the IgM greater than 1Og/l and lymphoedema of the legs. Bone marrow examination revealed 10-20% plasma cells. Three years later he died of cardiac failure and bronchopneumonia. At autopsy the small bowel had a grossly thickened and yellow submucosa, the muscle being thin and brown. Lymph nodes could not be located macrascopically. Microscopically the bowel had masses of lipid-laden macrophages resembling those found in Whipple’s disease; occasional ones were PAS-positive. The tissues about the major lymphatic ducts appeared fibrotic. The bone marrow had no evidence of any infiltration. The patient appears to have had Whipple’s disease of long standing, held in partial remission and modified by the courses of antibiotic therapy used for cellulitis in his legs, the latter no doubt predisposed by the sclerosis of the lymphatic system due to the underlying disease. THE CLINICAL SIGNIFICANCE OF SERUM TRIIODOTHYRONINE ASSAY WELLBY, M. L., KANAGASABAPATHY, A. S., GRAYCAR, LINDSAY E. and MARSHALL,JANETM. Departmmt of Clinical Chemistry, The Queen Elizabeth Hospital, Woodville, South Australia Triiodothyronine (T,)normally contributes about 70% of the total metabolic activity of the thyroid hormones in man. There are certain situations where this percentage is greatly exceeded and where the assay of serum total T, concentration is more important than the assay of total thyroxine (TJ. Radioimmunoassay (RIA) on unextracted serum samples was used for T, in this study, the mean level for 60 euthyroid normal volunteers being 136 ng/dl and standard deviation 26 (the reference range is 84-188ng/dl). The sensitivityof the assay is 12.5 pg/tube and the ‘between assay’ precision has a coefficient of variation of 8.9y0. The main clinical applications for serum T, were found to be as follows: 1. The diagnosis of the rare primary T, thyrotoxicosis.
66
THE ROYAL COLLEGE OF PATHOLOGISTS OF AUSTRALIA
2. For confirming the thyroid status of thyrotoxic patients previously treated with radioactive iodine (I3lI). Only 64.3””of euthyroid treated thyrotoxicosis patients had total T, in the reference range, whereas the total T, concentration was always in the reference range. 3. In thyrotrophin releasing hormone (RH) ’I stimulation studies. Normally serum T S H responses to T R H suffice but in patients with borderline clinical primary hypothyroidism, studies of serum T, responses were also very useful. In patients with 1311-treated thyrotoxicosis, it was shown that measurement of T:,responses to T R H is as essential as the response in TSH.
LABORATORY MANAGEMENT AND WORKLOAD RECORDING
WILLIAMS,MARJORIE J.
Veterans Adminisrration, Washinston, D.C.
Presented on behalf of rhe College of American Pathologists The College of American Pathologists is concentrating considerable effort in developing methods for measurement of the various components in laboratory management. Among its accomplishments is the development in conjunction with the Canadian Association of Pathologists of a Workload Recording Method for Clinical Laboratories, which is rapidly becoming a standard in North America. The precision of its nomenclature and definitions permit valid measurement while the unit values (weighting factors) add discrimination. Valuable information is accumulating on ranges of productivity for technical-clerical staff in hospitals and independent laboratories. Productivity is generally similar in all hospitals with more than 50 beds and the median approximates 45 unit values/paid man-hour in general hospitals. Productivity tends to be somewhat higher in independent laboratories with their more circumscribed operations. The continuing value of the Workload Recording Method is now assured with the establishment of procedures for self-renewal. A ‘universal’ protocol is availabk for collection of data for timing studies with centralized computer analysis support. New timing studies are accepted only after joint agreement on their validity. The Workload Recording Method through measurement of productivity can identify staffing requirements and, since salaries are major laboratory costs, the unit values become important in cost-finding procedures. Standard cost-finding techniques using the Workload Recording Method are now in preparation by the College and will be followed by the development of charts of accounts and publication of a manual.
SEQUENTIAL PATHOLOGICAL CHANGES SEEN I N CONTROLLED TRAUMA TO THE SPINAL CORD OF THE SHEEP
YEO,J. D. and PAYNE,W. H. Spinal Znjurizs Unit and Department of Clinical Pathology, The Royal North Shore Hospital of Sydney
Many patients with spinal cord damage suffer permanent paralysis and loss of sensation although the cord was severely bruised rather than lacerated by the displacement of the vertebral column. Experimental work has suggested that this apparently irreversible injury may be caused by ischaemia and could be at least partly reversed by the early introduction of physical or chemical treatment. In our experiment a controlled contusion injury is inflicted on the spinal cord of sheep. This shows swelling of the cord caused by congestion, haemorrhage and swollen axons and myelin sheaths. Between 2 and 4 h after the injury, breakdown and coalescence of myelin sheaths is the earliest structural evidence of permanent damage to the cord. When isotope rather than contrast myelography is used there is usually only partial obstruction to the flow of CSF so that the cord swelling alone is probably not responsible for the ischaemia. A local noradrenalin effect was suspected and a catecholamine antagonist injected within 1 h of the injury some reduction of the functional deficit and the size of the central cystic lesion in the cord was achieved. Further experiments are planned to measure the effect of alpha-methyl paratyrosine (a catecholamine antagonist) on the levels of noradrenalin in the blood and spinal cord.