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Biomedical subjects

P Jacobs

Publications and source records attributed to P Jacobs.

At least 505 records · Page 28Linked to original sources
PubMed1980

Effect of maternal age on autosomal trisomies.

The effect of maternal age on the genesis of trisomy was studied by comparing data from 362 trisomic and 790 chromosomally normal spontaneous abortions. As a group the trisomies were associated with a substantial increase in maternal age but there were considerable differences in the magnitude of the effect for different trisomies. The effect of increasing maternal age was most pronounced for trisomies involving the small chromosomes, both acrocentric and non-acrocentric. However, trisomy 16 was conspicuously different from trisomies for all the other small chromosomes, both in the reduced importance of increased maternal age and in the high frequency with which it occurred. The effect of increasing maternal age on trisomies for chromosomes in groups A, B and C was less clear than that for the small chromosomes. However, the evidence suggested that trisomy for these chromosomes was associated with a moderate increase in maternal age. It was suggested that the maternal age-dependent trisomies might result from precocious disjunction of the bivalents and random segregation of the resulting univalents, a process which would affect chromosomes with the fewest number of chiasmata and which might be more prevalent if oocytes of older women. It was further suggested that true non-disjunction, that is, the failure of bivalents to separate at anaphase, might also result in the production of trisomies. This process might be independent of, or only slightly influenced by, increasing maternal age but be affected by the presence of large blocks of heterochromatin.

Abortion, Spontaneous↗
PubMed1980

Expert explores avenues of economic alternatives.

"Economics focuses on relevant alternatives," asserts this author, and in the context of fund raising management, they can be incorporated into the solicitation process necessary to raise those big dollars. This author discusses three.

Financial Management↗
PubMed1979

An evaluation of the Ramco kit for serum ferritin assay.

The determination of serum ferritin levels may be of diagnostic importance in medicine. To establish whether values obtained using a commercially available kit (Ramco) were adequate for this purpose, a comparison was undertaken using a two-site immunoradiometric assay that had been developed and standardized in our laboratories. Over the range 6 micrograms/l to greater than 2 000 micrograms/l there was a correlation coefficient between the two methods of 0,8284 (P less than 0.001). It is concluded that the Ramco kit is suitable for use in clinical practice.

Blood Chemical Analysis↗
PubMed1979

Effects of the sulphonylurea drugs gliclazide and glibenclamide on blood glucose control and platelet function.

Platelet aggregation and adhesion are commonly increased in diabetes mellitus. These abnormalities may in part be responsible for the increased incidence of vascular disease in diabetics. We have investigated the effects of diet, diet plus glibenclamide, and diet plus gliclazide on plasma glucose control and platelet function in 10 newly diagnosed maturity-onset diabetics who had not previously been treated. Before treatment, the mean postprandial plasma glucose value was 13,4 +/- 0,8 mmol/l, which fell insignificantly on dietary treatment, to 12,2 +/- 1,0 mmol/l (P greater than 0,05). Both glibenclamide and gliclazide, when added to the diet, significantly lowered mean plasma glucose values to 9,3 +/- 0,8 mmol/l and 7,8 +/- 0,8 mmol/l respectively (P less than 0,05). Platelet aggregation in response to 1 mumol adenosine diphosphate (ADP) was increased in the diet period, whereas aggregation in response to 10 mumol and 100 mumol was normal. This suggests an increased sensitivity of the platelets to ADP in diabetic patients. The addition of both glibenclamide and gliclazide reduced the magnitude of the response to within the normal range. Platelet aggregation in response to 10 mumol adrenaline and 750 micrograms/ml collagen was significantly reduced by glibenclamide (P less than 0,05). We conclude that sulphonylurea therapy appears to reduce the increased platelet aggregation which occurs in diabetics. This may play a role in the prevention of vascular disease.

Adult↗
PubMed1979

Absorption of iron polymaltose and ferrous sulphate in rats and humans. A comparative study.

Free iron in the circulation in contrast to iron complexed with protein or carbohyrdate, is intensely toxic. The annual morbidity and mortality from accidental overdose with iron salts is significant and has directed attention to the evaluation of safer forms of therapy. Comparative studies between oral ferrous sulphate and iron polymaltose in rats established an LD100 of 350 mg/kg for the salt, whereas neither morbidity nor mortality could be produced in doses exceeding 1 000 mg/kg for the complex. Bio-availability of iron from salt and complex for haemoglobin synthesis was then compared both in rats and in man with a twin-isotope technique. In experimental animals and in the human studies, venesected individuals were used to reproduce the iron deficiency state where treatment would be indicated. It was concluded that bioavailability is comparable for therapeutic doses of ferrous sulphate and iron polymaltose in iron-deficient subjects. The marginally lower absorption of complex was offset by a greater degree of gastrointestinal tract tolerance; the wide margin of safety may be of importance in reducing the danger of accidental iron overdose.

Anemia, Hypochromic↗
PubMed1979

Agnogenic myeloid metaplasia and spinal cord compression.

A 55-year-old White male with agnogenic myeloid metaplasia, proved on bone marrow trephine biopsy, underwent splenectomy for abdominal discomfort. Six months later he developed paraparesis and on myelography multiple extradural obstructions were seen. In the absence of other obvious diagnostic possibilities, these were attributed to areas of extramedullary haematopoiesis, and he was treated with local radiotherapy. However, the neurological deficit progressed and emergency laminectomy and decompression were undertaken. Tissue obtained at this time confirmed the diagnosis of agnogenic myeloid metaplasia. A repeat myelogram showed complete relief of the obstruction, but the patient developed fulminating septicaemia and died. These findings are reported in view of the great rarity of spinal cord compression due to multiple areas of extramedullary haematopoiesis.

Humans↗
PubMed1979

Fatal veno-occlusive disease of the liver after chemotherapy, whole-body irradiation and bone marrow transplantation for refractory acute leukaemia.

Rapid onset of liver failure with fatal outcome occurred in a young woman after successful bone marrow transplantation undertaken for refractory acute leukaemia. Centrilobular necrosis was demonstrated at autopsy and was attributed to prior cytotoxic chemotherapy, possibly potentiated by the total-body irradiation that was used in preparation for the transplant. This association between liver damage and prolonged drug therapy, coupled with the short median survival currently achieved within these chemotherapy regimens, has initiated an evaluation of bone marrow transplantation in patients with leukaemia during the first complete remission, rather than at a later stage when cumulative drug toxicity to the liver may have taken place.

Adolescent↗
PubMed1979

A comparative randomized trial of heparin versus streptokinase in the treatment of acute proximal venous thrombosis: an interim report of a prospective trial.

A controlled, prospective study comparing streptokinase and heparin treatment has been completed in 51 patients presenting with acute proximal venous thrombosis of less than 8 days' clinical duration. Patients were studied by means of pre-treatment, post-treatment, 3- and 12-monthly phlebography and pulmonary perfusion scanning and were followed up at 3-monthly intervals. Of the 26 patients randomized to receive streptokinase, therapy was stopped in 3 because of complications. Phlebography 5 days after starting treatment showed 80--100 per cent lysis in 17 of the 23 patients who completed the course of streptokinase. Two patients later developed partial rethrombosis. One patient developed an asymptomatic pulmonary embolus during treatment. During follow-up (mean 19 months) only 1 of the 17 patients with 80--100 per cent lysis developed postphlebitic symptoms, 3 patients died of unrelated causes and 1 patient was lost to follow-up. In patients randomized to heparin therapy no significant lysis was achieved in any of the 25 patients and only 2 of these patients were found to have asymptomatic legs on follow-up. Two patients in this group died and autopsy confirmed massive pulmonary embolus during treatment. These data suggest that streptokinase is superior to heparin in the treatment of acute proximal venous thrombosis of less than 1 week's clinical duration especially if the thrombus is largely non-occlusive. It must be stressed that in order to avoid the bleeding complications of thrombolytic therapy, streptokinase must not be used within 10 days of major surgery, or even longer after vascular, neurosurgical or eye operations.

Adult↗