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J A Cuthbert

Publications and source records attributed to J A Cuthbert.

59 records · Page 4Linked to original sources
PubMedDate not supplied

Primary pulmonary hypertension: an unusual case associated with extrahepatic portal hypertension.

A patient with both extrahepatic portal hypertension and primary pulmonary hypertension is reported. The pulmonary hypertension developed without a surgical portal-systemic shunt, and at autopsy there was no evidence of a large spontaneous shunt. This association of pulmonary arterial hypertension and portal venous hypertension without either intrinsic liver disease or a large portal-systemic anastomosis has not been reported previously. Our case supports the concept that portal hypertension with its attendant portal-systemic collateral circulation may be the major predisposing cause of pulmonary hypertension both in intrinsic liver disease and extrahepatic portal vein obstruction.

Adolescent↗
PubMedDate not supplied

Bone disease in primary biliary cirrhosis: increased bone resorption and turnover in the absence of osteoporosis or osteomalacia.

The role of vitamin D in hepatic osteodystrophy was examined. Eleven unselected patients with primary biliary cirrhosis (PBC) were assessed for disorders of mineral and vitamin D metabolism. Six were not receiving supplementary vitamin D, and five were being treated with oral vitamin D (50,000 IU daily). Serum levels of 25-hydroxyvitamin D were normal in all patients receiving oral therapy and in 4 of 6 untreated patients. Levels of serum 1,25-dihydroxyvitamin D and 24,25-dihydroxyvitamin D were normal or near normal in all patients. Studies were repeated after 6 months of therapy with parenteral vitamin D2 (100,000 IU i.m. monthly) in 7 patients. Initial bone histomorphometry revealed no evidence of osteomalacia or osteoporosis. However, the bone resorption surface of trabecular bone was increased. This abnormality was no longer present on repeat bone biopsies obtained after parenteral vitamin D therapy, and bone formation had decreased. In addition, trabecular bone volume remained normal in the face of the lower rate of bone formation. Increased bone resorption surface in the absence of osteoporosis or osteomalacia has not been previously described in PBC. Improvement in this bone parameter, associated with the finding of a decrease in the formation of bone and in hydroxyproline excretion in urine after parenteral vitamin D, suggests that increased turnover may be an early feature of the bone disease which complicates PBC and that parenteral vitamin D may retard the rate at which hepatic osteodystrophy develops in chronic cholestatic liver disease.

Adult↗
PubMedDate not supplied

Identification of low density lipoprotein receptor abnormalities by assaying functional receptors on proliferating lymphocytes.

Lymphocyte proliferation stimulated by mitogenic lectins is dependent on exogenously supplied cholesterol when endogenous cholesterol synthesis is blocked with the specific inhibitor mevinolin. Lymphocytes from patients homozygous for familial hypercholesterolemia (FH) lack low density lipoprotein (LDL) receptors, and, therefore, these patients cannot use LDL cholesterol to support proliferation when endogenous sterol synthesis is blocked. Thus, LDL receptors are required for the uptake of exogenous lipoprotein cholesterol by proliferating lymphocytes. As a result, the number of functional receptors can be assessed when endogenous sterol synthesis is inhibited and when limiting concentrations of LDL are employed to support lymphocyte proliferation. Lymphocytes from patients heterozygous for LDL receptor abnormalities can be distinguished from normal lymphocytes since the former require twice the concentration of LDL for proliferation. By contrast, in hyperlipidemia not caused by FH, lymphocyte LDL receptor activity is normal, indicating that plasma cholesterol levels do not account for abnormalities in LDL receptor function assayed in this way. Therapy with cholesterol-lowering drugs, however, can alter lymphocyte LDL receptor activity in patients with heterozygous FH. Patients with heterozygous FH respond to therapy with mevinolin and a bile-acid-binding resin by lowering plasma cholesterol levels. In some patients, treatment with cholesterol-lowering plasma cholesterol levels. In some patients, treatment with cholesterol-lowering plasma cholesterol agents is also associated with normalization of functional lymphocyte LDL receptor activity, thereby providing direct evidence that therapy can alter LDL receptor expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Cycle↗