PubMed Health⌕ Search

Biomedical subjects

W H Butler

Publications and source records attributed to W H Butler.

At least 55 records · Page 3Linked to original sources
PubMed1977

Hepatic structure and function after modified jejunoileal bypass surgery for obesity.

The most serious adverse effect of standard intestinal bypass for obesity is the high incidence of hepatic dysfunction and death from hepatic failure. We therefore examined the long-term effects of a modified form of jejunoileal bypass (in which a greater continuous length of ileum is retained), on liver function in 120 patients. Substantial weight loss (119-0+/-SD 23-3 kg to 82-3+/-18-8 kg) occurred during the first nine months after surgery, accompanied by a significant rise in serum concentrations of bilirubin, alanine transferase, and alkaline phosphatase, and a significant reduction in albumin concentrations. Biochemical changes were unrelated to weight loss or halothane anaesthesia. After weight stabilisation liver function reverted to normal, and four years after bypass sulphobromophthalein retention and hepatic histology did not differ from those in obese controls. There were two postoperative deaths. Three other patients died during the period of rapid weight loss with severe hepatic steatosis. While transient mild impairment of liver function is common after modified jejunoileal bypass, clinically significant hepatic dysfunction is a rare and unexplained early complication.

Adult↗
PubMed1977

Vascular changes in the lungs of rats after the intravenous injection of pyrrole carbamates.

The effects on the lung of some synthetic compounds related to monocrotaline pyrrole have been studied and compared with those previously found with that compound. When injected into a systemic vein doses of pyrrole mono- and dicarbamate produced acute pulmonary oedema. Pyrrole alcohol and ethyl carbamate had no such effect and although furyl carbamate did not cause pleural effusion in rats it did so in mice. Like monocrotaline pyrrole, when injected into other vessels the pyrrole carbamates produced oedema in the region of the first capillary bed encountered. When colloidal carbon was injected intravenously after the pyrrole carbamates, carbon "labelling" was seen in both the post-capillary venules and the capillaries of the lungs. On the whole, venular "labelling" occurred before capillary "labelling" which was best seen when the carbon was injected more than 4 hr after the pyrrole. The distribution of the carbon as seen by electron microscopy is described. No "labelling" was seen after furyl carbamate. The effects of the synthetic pyrrole esters were similar to those of monocrotaline pyrrole. Although both the pyrrole carbamates were less active on a molecular basis they had a broader action on the pulmonary vasculature causing venular as well as capillary "labelling". To affect the lungs acutely the compound had to have the pyrrole ring structure and at least one ester side-chain.

Animals↗
PubMed1977

Mode of action and human health aspects of aflatoxin carcinogenesis.

The toxicity and carcinogenicity of the aflatoxins have been studied extensively in the rat. In this species these compounds are recognized as some of the most active hepatocarcinogens. The early lesions induced by the aflatoxins have been studied in an attempt to recognize the developing malignant neoplasm prior to the presence of metastasis. The relationship of focal hyperplasia to neoplasia will be discussed in comparison with other recognized carcinogens. The pattern of human hepatic neoplasia will be compared with that of neoplasia induced by the aflatoxins in order to add weight to the "mycotoxin hypothesis" of the aetiology of hepatic neoplasia. The role of dietary modification will also be discussed.

Aflatoxins↗
PubMed1976

The kinetics of methylmercury administered repeatedly to rats.

Female rats (65-75 days old) were given orally 0.84 or 3.36 mg Hg/kg as methylmercury chloride (MeHgCl) 5 times a week for 13 and 3 weeks, respectively. The proportion of inorganic to total mercury remained as low as 6% in whole animal though it increased to above 40% in the kidneys. Differences in organ half times and the negative correlation with time for blood to liver, brain and kidney mercury ratios indicated more than one compartment for MeHg+. Brain had 26 days half time with a 32% final equilibrium concentration in relation to the body concentrations. Brain concentrations of mercury reported on rats dosed repeatedly with MeHg+ agreed with these values which justifies their use when experiments are planned to give a certain brain MeHg+ concentration. Half time for the whole body was 34 days but patholgical changes-weight loss, tubular damage, slow gastrointestinal passage-disturbed the accumulation curves in the higher dose group. Blood to kidney ratio and uptake of MeHg+ by kidneys also changed significantly.

Administration, Oral↗
PubMed1976

Some effects of acute and chronic dosing with aflatoxin B1 on rat liver nuclei.

A study has been made of changes occurring in rat liver nuclei as a result of the chronic and acute administration of aflatoxin B1. This has involved resolution of the nuclei into populations of differing ploidy by means of centrifugation in a zonal rotor. Chronic feeding of the toxin to weanling rats prevents the development of the predominant tetraploid hepatocyte nuclear population, which normally takes place during maturation. Increased populations of diploid and octaploid hepatocyte nuclei are observed. Chronic feeding of the toxin to adult animals also causes a reduction in the tetraploid population already established and, again, leads to increased numbers of diploid and octaploid nuclei. Once an abnormal nuclear population has been established by feeding the toxin, it persists until the development of hepatocarcinoma (if a 6-week carcinogenic feeding regimen has been used). The hepatomas have diploid nuclei. Labeling hepatic RNA and DNA in vivo has indicated that feeding the toxin causes a reversion to the immature distribution of DNA synthesis among the nuclear population, with little effect on the pattern of distribution of RNA synthesis. Acute administration of aflatoxin to adult rats also causes a reduction in the size of the tetraploid population, with increased proportions of diploid, octaploid, and higherploidy nuclei. These results are discussed in terms of a dual action of the toxin, antimitotic and necrogenic, and the possible relationship of these to the carcinogenic process.

Aflatoxins↗