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Biomedical subjects

J M Little

Publications and source records attributed to J M Little.

At least 199 records · Page 11Linked to original sources
PubMed1979

Arterial reconstruction with polytetrafluoroethylene: a preliminary report.

Early results of arterial reconstruction with reinforced expanded polytetrafluoroethylene (PTFE) in the lower extremity have been obtained by reviewing 55 patients undergoing 59 operations - 38 femoropopliteal bypasses and 21 long bypasses distal to the popliteal artery. The one-year accumulated patency rates were 73% for the femoropopliteal bypass group and 50% for the long bypass group. Early results suggest that PTFE is superior to Dacron and is an acceptable substitute for autogenous saphenous vein when the latter is unavailable or of inadequate calibre.

Adult↗
PubMed1979

The carcinoid tumour.

Carcinoid tumours are by no means rare. The wide range of sites in which they occur is explained by their origin from APUD cells of the neural crest. These cells migrate to all parts of the alimentary tract during embryonic life, and ultimately are found as well in various gut derivatives such as the respiratory, pancreatic and biliary systems. On the basis of a series of 31 carcinoid tumours seen at the Royal Prince Alfred Hospital in a five-year period, the distinctive clinical and histological features of carcinoids of foregut, midgut and hindgut origin are reviewed. Diagnosis, treatment and results are discussed, and recommendations regarding management of the patient with a carcinoid tumour are given.

Adolescent↗
PubMed1979

Synthesis of taurocholate by rat fetal liver in organ culture: effects of cortisol in vitro.

Taurocholate production by fetal hepatic organ cultures was measured by radioimmunoassay. Taurocholate production was maximal on day 1 of in vitro incubation, but was demonstrable in organ cultures maintained for periods up to 15 days. Explants obtained from fetuses of 18 gestational days of age produced only 82 pmol taurocholate per milligram dry weight of tissue during the first 24 h of incubation. Explants obtained from fetuses 21 gestational days of age produced 1,043 pmol taurocholate per milligram dry weight. The presence of cortisol (2.0 X 10(-6) M) in the incubation medium increased synthesis of taurocholate by rat fetal liver in which total taurocholate rose 50-fold above control after 120 h of incubation. In increasing concentrations from 2.0 X 10(-9) M to 2.0 X 10(-7) M, cortisol produced an incremental rise in taurocholate. However, additional increases in cortisol dose failed to provide further stimulation, and taurocholate production was inhibited by cortisol concentrations of 2.0 X 10(-5) M. The results provide further validation for the technique of fetal hepatic organ culture. They demonstrate that taurocholate synthesis is increasing rapidly during the final stages of gestation and show that cortisol augments taurocholate synthesis in a dose-response pattern.

Animals↗
PubMed1979

Taurocholate pool size and distribution in the fetal rat.

Taurocholate concentrations in fetal and neonatal rats were determined by radioimmunoassay. Total body taurocholate pool size varied from 0.0049 +/- 0.0008 to 203 +/- 8 nmol/g body weight from day 5 of gestation to 5 d after birth. A 50-fold increase in taurocholate pool size was observed between days 15 and 19 of gestation. The distribution of taurocholate between liver, intestine, and the remainder of the carcass was determined for rats of gestational age 19 d to 5 d after birth. The major fraction of total body taurocholate was in the liver and intestine, with less than 15% in the remainder of the carcass. The ratio of taurocholate in intestine to taurocholate in liver, which was 1:17 at 19 d of gestation, had altered substantially to a ratio of 6:1 by 5 d after birth. Treatment of pregnant rats with 60 microgram/d of dexamethasone from gestational day 9 until sacrifice increased fetal taurocholate pool size by 80% at 15 d, 40% at 19 d, and 16% at 1 d after birth. Administration of dexamethasone to the mother also changed the ratio of taurocholate in intestine to taurocholate in liver. At 19 d of gestation, dexamethasone-treated mothers had fetuses with approximately equal amounts of taurocholate in intestine and liver. This suggested that adrenocorticosteroids stimulate the early maturation of factors controlling taurocholate pool size and tissue distribution in the rat fetus.

Animals↗
PubMed1978

Liver tumours associated with oral contraceptives.

Five young women have been encountered with unusual forms of hepatic neoplasms in a ten year period. Each had been taking an oral contraceptive. Two of the four women with benign lesions noted the presence of their tumours, and another woman presented with abdominal pain. Each of these tumours was resected successfully. The fourth patient had the diagnosis made at laparotomy following the development of haemoperitoneum after an attempt at percutaneous liver biopsy. A fifth patient developed jaundice and investigation revealed a hepatocellular carcinoma which was invading the biliary tree. This experience illustrates the need for periodic physical examination of young women who are taking oral contraceptives.

Adenoma↗
PubMed1978

Optic nerve in globoid leukodystrophy (Krabbe's disease). Ultrastructural changes.

Globoid leukodystrophy (Krabbe's disease) was diagnosed in an infant in whom a progressive neurological disorder and optic atrophy developed. At autopsy, ultrastructural examination of the optic nerves and cerebral white matter revealed characteristic tubular inclusions in globoid-epithelioid cells. Thinning of the nerve fiber and ganglion cell layers of the retina appeared to be due to retrograde degeneration of the optic nerve related to the abnormal metabolism of myelin. We discuss the pathogenesis of the clinical and pathological ocular findings, with regard to the inherited absence of the enzyme galactocerebroside beta-galactosidase and the accumulation in the optic nerve and brain of its substrates, galactocerebroside and psychosine.

Brain↗
PubMed1978

Bleeding oesophageal varices.

At the Royal Prince Alfred Hospital, most patients with bleeding varices have been poor-risk alcoholics. A high proportion were receiving a State pension. The early mortality due to bleeding varices was 53%. This figure comprised a 60% mortality following conservative management and 40% after urgent shunt. All patients having urgent operations which were not portal decompression died. No patient who had an elective shunt died. In a mean follow-up period of 15.4 months, a further 14% of survivors died. No form of conservative management appeared to have much effect on the natural history of the bleeding. A blood replacement of more than five litres indicated that spontaneous cessation of haemorrhage was unlikely. Shunt operations usually controlled haemorrhage, but hepatorenal failure was common after the urgent shunts. The cost of operation was greater than that of conservative management, but in neither case was it considered excessive.

Adolescent↗
PubMed1977

Alcohol: its effect on the kidney.

The effect of ethanol feeding on renal function, gross and microscopic morphology and constituent analysis was determined and compared to similar studies in isocalorically fed animals ingesting the same diet except that dextrimaltose was isocalorically substituted for ethanol. Alcohol-fed animals have significantly reduced renal function (p less than 0.01) and interstitial edema compared to their isocaloric controls. When renal mass and renal constituent analysis were normalized for body weight, alcohol-fed animals were found to have renal hypertrophy characterized by significantly increased absolute amounts of protein (p less than 0.01), fat (p less than 0.01) and water (p less than 0.01). All of these constituents increased in proportion to their percentage of total renal mass in control animals. In contrast, DNA content per kidney was similar for alcohol and isocalorically fed animals.

Animals↗
PubMed1977

Dietary protein level and experimental aortic atherosclerosis.

White Carneau pigeons were fed diets containing three levels of protein (compensated for by changes in the dextrin level); all other dietary constituents, including cholesterol, were at the same level, and these diets were fed for nine months, when the birds were killed and necropsied. Group A, which was fed the lowest level of dietary protein (10%), which is considerably less than that in Pigeon Chow Checkers, showed a high mortality rate (50%) and the survivors showed a significant loss in body weight. The birds in the other two groups, B and C (20 and 40% protein respectively) showed no significant changes in body weight during the experiment. When the mean serum uric acid values for the last four blood sampling periods, at two months intervals, in the last seven months of the experiment were compared with the values for A, only Group C showed a significant increase. There was no significant difference in serum total cholesterol concentrations, when compared in the same way. There were no significant changes in either the aorta atherosclerosis indices or the mean aorta cholesterol concentrations, determined after necropsy. If one compares the serum total cholesterol concentration for the groups of pigeons, of the blood samples drawn the day before they were killed, there were significant increases observed for Groups B and C. This work does not support the suggestion previously made that the dietary protein cholesterol interact in determining the concentration of aorta cholesterol and the atherosclerosis index in this breed of pigeon.

Animals↗
PubMed1977

Alcohol: its effect on the kidney.

The effect of ethanol feeding on renal function, gross and microscopic morphology, and constituent content was determined in alcohol-fed rats and compared to similar studies in isocalorically fed animals ingesting the same diet except that dextrimaltose was isocalorically substituted for ethanol. Alcohol-fed animals have significantly reduced renal function and interstitial edema compared to their isocaloric controls. When renal mass and renal constituent analysis were normalized for body weight, alcohol-fed animals were found to have renal hypertrophy characterized by significantly increased absolute amounts of protein (p less than 0.01), fat (p less than 0.01), and water (p less than 0.01). All of these constituents increased in proportion to their percentage of total renal mass in control animals. In contrast, DNA content per kidney was similar for alcohol and isocalorically fed animals.

Alanine Transaminase↗
PubMed1977

Benign non-parasitic cysts of the liver: a review of 18 cases.

Benign non-parasitic cysts of the liver are a clinical and pathological curiosity except when they cause symptoms or are incorrectly diagnosed as metastases in patients with abdominal malignancy. It is difficult to make a correct diagnosis of benign liver cysts in spite of the armamentarium of modern diagnostic aids available, and on many occasions the diagnosis is made at laparotomy. This is a report of 18 patients with benign cysts of the liver, two of whom suffered complications which we believe have not previously been reported.

Adolescent↗
PubMed1977

Fetal bile salt metabolism. The intestinal absorption of bile salt.

The intestinal absorption of sodium taurocholate was studied in the near-term fetal and neonatal dog. Absorption rates were measured in vivo in isolated loops of fetal jejunum and ileum. Absorption was also measured in vitro in everted sacs and rings of fetal and neonatal jejunum and ileum. The maximal rates of taurocholate absorption observed after instillation of 1 micronmol taurocholate into closed segments of fetal jejunum and ileum with intact blood supply were not significantly different (P less than 0.2), and equalled 0.282+/-0.026 (mean+/-SEM) and 0.347+/-0.051 micronmol/h per 10-cm segment length jejunum and ileum, respectively. Similarly, the rates of absorption from open segments of jejunum and ileum perfused with 0.4 and 1.0 mM taurocholate were nearly identical (0.232+/-0.040 and 0.255+/-0.039, respectively at 0.4 mM, and 0.470+/-0.065 and 0.431+/-0.013, respectively at 1.0 mm) (P greater than 0.2). At perfusate concentrations of 4.0 mM, moreoever, jejunal absorption exceeded ileal absorption (1.490+/-0.140 and 0.922+/-0.200, respectively (P less than 0.05). As expected, concentration of taurocholate by the mucosa was readily demonstrated in adult ileal, but not in adult jejunal everted rings. In contrast, there were no significant differences in mucosal uptake of taurocholate by fetal jejunal and ileal rings. Fetal ileal mucosal concentrations were not significantly above those in the incubation medium after 1-h exposure of the mucosa to 0.003, 0.03, and 0.3 mM taurocholate. Uptake was proportional to incubation medium concentration over the full range of values. This was also true of tissues from 1-wk-old neonates. However, by 2 wk of age, ileal mucosal concentration of taurocholate was evident and adult levels were attained by 5 wk of age. It is concluded that taurocholate is absorbed by the fetal gut and that ileal absorption is no more efficient than jejunal absorption. Although active glucose transport was demonstrable in both jejunum and ileum, it was not possible to demonstrate an ileal mechanism for active transport of taurocholate in the fetus. Active ileal transport was not demonstrable in the newborn until at least 2 wk after birth.

Age Factors↗
PubMed1977

Autogenous veins and velour dacron in femoropopliteal arterial bypass.

Sixty-five patients treated by femoropopliteal bypass in 1974 were surveyed; the mean follow-up time was 10.4 months. The one year cumulative patency rate for velour Dacron was 50 percent; this was less successful than were the results from a comparable group in which vein grafts were used (79 percent). These poor results were due principally to the high failure rate of velour Dacron in patients suffering from clinically severe ischemia. In these only one in four grafts remained patent. If a less than perfect arteriographic runoff was obtained, only one in three still functioned. These results occurred despite high intraoperative graft flows. It appears that velour Dacron may be acceptable in patients treated for claudication if no adequate vein is available. This prosthesis gives an unacceptably high failure rate in patients with severe ischemia.

Adolescent↗