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Biomedical subjects

M N Lowenthal

Publications and source records attributed to M N Lowenthal.

At least 37 records · Page 2Linked to original sources
PubMed1993

Resolution of hypertensive retinopathy despite persistent high diastolic pressure.

Four patients with exudative retinopathy due to hypertension were observed for periods ranging from 12 to 35 months. Despite multiple drug therapy in high dosage and some clinic attendance, blood pressure was not controlled and remained severely elevated. Even though severe hypertension persisted, however, exudative phenomena disappeared and renal function remained stable during the follow-up period. Neither the pathogenesis nor the natural course of hypertensive retinopathy is yet fully understood. It is accepted that antihypertensive therapy causes gradual regression of the retinal changes of hypertensive retinopathy. There are no data concerning the natural course and progress of hypertensive retinopathy in patients with severe untreated hypertension. It is unclear why the patients in our study had complete regression of hypertensive retinopathy.

Adult↗
PubMed1990

Calcitonin in Ghanaians and Israelis.

Calcitonin (CT) in serum was measured in a group of (black) Ghanaian traumatic fracture patients (GFP) and in two healthy control groups, (black) Ghanaian (GMS) and (white) Israeli (IMS) medical students. CT (mean +/- SD) in GFP, GMS and IMS was, respectively, 17.2 +/- 6.4, 15.5 +/- 2.8 and 7.6 +/- 3.3 pmol/l. The mean difference between the GFP and GMS was not significant, but that between the Ghanaian groups combined and IMS was 8.8 pmol/l, 95% CI 4.1-13.7, P less than 0.001. Observations elsewhere that CT levels in adult blacks in the tropics are higher than those in whites are confirmed.

Adult↗
PubMed1990

Acromegaly and proximal femoral fracture in an aged person: bone histomorphometry, vitamin D metabolites and parathormone.

Osteoporosis and fractures are rare in acromegaly. An 84-year-old acromegalic woman sustained a fractured neck of femur in a fall. Histomorphometric analysis of an iliac crest biopsy showed marked osteoporosis and augmented resorption parameters. Cortical plates were very thin and bone volume was 8.5%; 12.5% is the reference value for women at this age. The total resorption surfaces were 23.7% compared with the reference value of 8%. We conjecture that postmenopausal and involutional osteoporosis were far advanced before the development of acromegaly, explaining the coexistence of the two conditions. Parathormone (65 pmol/l) and 24,25-dihydroxyvitamin D (1.34 ng/ml) levels were within normal limits, but those of 25-hydroxyvitamin D (5.6 ng/ml) and 1,25-dihydroxyvitamin D (15 pg/ml) were markedly decreased.

Acromegaly↗
PubMed1988

Vitamin D-deficiency in the elderly: treatment with ergocalciferol and hydroxylated analogues of vitamin D3.

The purpose of the present work was to study the effect of vitamin D and its metabolites in correcting hypovitaminosis D in the elderly. Thirty elderly people (mean age 78.4 years) participated in this study. They all had low serum levels of 25-hydroxyvitamin D (25-OH-D), of 24,25-dihydroxyvitamin D [24,25(OH)2D] and of 1,25-dihydroxyvitamin D [1,25(OH)2D]. These low levels did not increase in nine subjects after oral administration of vitamin D2 (3,000 IU/day for 12 weeks). However, administration of 1 alpha-hydroxyvitamin D3 (1 alpha-OH-D3) to 12 other subjects (0.5 micrograms/day for 8 weeks) led to a significant increase in the serum levels of 1,25(OH)2D. The other vitamin D metabolite levels remained unchanged. A significant increase in the levels of all three main vitamin D metabolites was obtained following administration of 25-hydroxyvitamin D3 (25-OH-D3) to a third group of nine subjects (25 micrograms/day for 1 week). These results suggest that vitamin D nutrition in elderly people insufficently exposed to the sun could be maintained by regular administration of 25-OH-D, whereas the administration of native vitamin D (ergocalciferol) in the doses used was inadequate for vitamin D nutrition.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Cardiomegaly in Northern Zambia: clinico-pathological observations.

Massive cardiomegaly (heart weight above 400 g in females and 450 g in males) was studied in 26 Zambians examined post mortem. The aetiologies found were: hypertensive heart disease alone in six cases; hypertensive and alcoholic heart disease in two cases; alcoholic heart disease alone in five; alcoholic and pulmonary heart disease in one; alcohol with possible hypertensive heart disease in one. Eleven cases were classified as being idiopathic mainly due to lack of data and in five of these hypertension was suspected as being the cause. The series qualitatively represented the spectrum of non-rheumatic heart disease seen in patients admitted to the Central Hospital, Ndola, Zambia. Hypertension had a central role in the causation of massive cardiomegaly. Follow-up of several patients enabled observations on the cardiac effects of hypertension and alcoholism operating simultaneously and on the relationship between hypertension and congestive cardiomyopathy.

Adult↗
PubMed1980

Massive splenomegaly in Northern Zambia. I. Analysis of 344 cases.

Massive splenomegaly is common in Northern Zambia. Nearly 40% of 344 patients were diagnosed as Tropical Splenomegaly Syndrome of malarial origin. Portal hypertension, lymphoreticular and haemopoietic malignancies, and schistosomiasis accounted for another 46%. The common causes of splenomegaly show differences of frequency within Zambia and also between Zambia and other African countries.

Adolescent↗
PubMed1980

Massive splenomegaly in Northern Zambia. II. Schistosomal splenomegaly and elevated IgG.

Twenty-three patients from Northern Zambia with massive splenomegaly due to chronic schistosomiasis were studied. The mean serum IgG levels were found to be extremely high compared with local blood donors and local patients with Tropical Splenomegaly Syndrome (TSS). Mean serum IgG levels also appear to be higher in Zambians with schistosomal splenomegaly than in those reported in patients from most other areas. Mean IgM levels of patients with schistosomal splenomegaly were higher than those of local blood donors, but not as high as in the TSS. IgG and IgM estimations are sometimes of value in the differential diagnosis of splenomegaly in the tropics.

Adolescent↗
PubMed1979

Hypertensive heart disease and cardiomyopathy in blacks. Diagnostic confusion.

Four Black South African patients, representative of a larger group, are described in detail. The common features were long periods of observation, multiple hospital admissions in both normotensive and hypertensive cardiac failure, hypertensive retinopathy and good renal function. All had been diagnosed as having cardiomyopathy. Two of the patients in a normotensive phase became hypertensive after responding to therapy for heart failure. One patient with malignant hypertension showed the features of idiopathic cardiomyopathy at necropsy. These cases are regarded as evidence in favour of the hypothesis that many cases of cryptogenic heart disease (cardiomyopathy, congestive cardiomyopathy, idiopathic cardiomegaly) are in fact cases of hypertension presenting with normotensive cardiac failure.

Adult↗