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Biomedical subjects

W Burnett

Publications and source records attributed to W Burnett.

At least 37 records · Page 2Linked to original sources
PubMed1979

In vitro studies of gallstone dissolution using the scanning electron microscope.

Scanning electron microscope studies on cholesterol gallstones, which had been subjected to, but had not been completely dissolved by, chenodeoxycholate and deoxycholate salts, have indicated the presence of an insoluble organic matrix, probably a mucopolysaccharide. Solution of a gallstone in vitro is enhanced by the addition of heparin which dissolved this matrix, thus allowing complete dissolution of cholesterol in a gallstone.

Chenodeoxycholic Acid↗
PubMed1978

Black pigment stone in a male child aged two years and seven months.

A case of cholelithiasis is reported occurring in a boy aged two years and seven months. The patient presented with biliary colic, and cholecystectomy was performed. Detailed analysis of the stone, including electron-probe studies, showed it to be an example of a polybilirubinate stone, containing also calcium, carbonate, and phosphate, with some sulphur, sodium, and magnesium. There were also traces of chlorine, aluminium, copper, nickel, and manganese.

Child, Preschool↗
PubMed1978

Chemoimmunotherapy in disseminated melanoma and colorectal carcinoma.

Non-specific immunotherapy with monthly intramuscular injection of Corynebacterium parvum has been investigated by randomized clinical trials in patients with advanced cancer. Thirty-six patients with disseminated melanoma were treated with either imidazole carboxamide (DTIC) alone or DTIC plus C.parvum. A 19% objective response rate was observed. The mean survival time was similar for both groups. Thirty-three patients with disseminated colorectal cancer were treated with either 5-fluorouracil (5FU) alone or 5FU plus C.parvum. No objective responses were observed. The mean survival time was similar for both groups. No advantage has been demonstrated in either tumour group by adding C.parvum to standard chemotherapy.

Bacterial Vaccines↗
PubMed1977

In vitro studies of gallstone dissolution using bile salt solutions and heparinized saline.

A controlled in vitro study of gallstone dissolution has been carried out using a model designed to simulate the in vivo situation in the bile ducts. Sodium taurocholate, sodium cholate, heparinized saline and physiological saline were infused for 10 days over 81 stones from 32 patients and changes in weight and structure were recorded. The bile salt solutions caused weight loss in 81-5 and 85-7 per cent respectively of the stones treated, but the two saline solutions caused weight gains in 74-5 and 88 per cent respectively. Fragmentation occurred in 18-5% of stones treated with sodium taurocholate, in 25% of those treated with sodium cholate and in 11-8 per cent of those treated with heparinized saline. Small stones lost a lower absolute amount of weight than large stones but this represented a greater proportion of their initial weight. These investigations confirm the advantages of a dynamic in vitro model to study gallstone dissolution. Bile salt solutions infused into the bile ducts may clear retained stones by causing reduction in stone weight or fragmentation or both, but heparinized saline appears to be unsuitable for gallstone dissolution. Larger stones may require longer periods of infusion.

Bile Acids and Salts↗
PubMed1977

An electron microscopic study of the mode of donor cell death in unmodified rejection of pig liver allografts.

The only type of cell death found in pig liver allografts 1 week after technically successful operation was apoptosis. Its extent paralleled the degree of mononuclear cell infiltration of the liver parenchyma, and mononuclear cells were found applied to the surfaces of hepatocytes showing early stages of the process. The results suggest that cellular immune attack induces apoptosis of donor cells, and that the action is a direct one. However, implication of other factors such as vascular damage in the induction of apoptosis in the grafts could not be excluded.

Animals↗
PubMed1977

Epidemiology of cancer of the testis in upstate New York.

We collected data on the 434 individuals reported with cancer of the testis to the New York State Tumor Registry, 1960-64, from upstate New York. We compared these with the 410 members of a random sample of the upstate population interviewed from 1959 to 1962. A high risk of developing cancer of the testis was associated with professional occupations, native-born parentage, rural residence, and having been married, especially while young. These findings paralleled some other studies, as well as our earlier inquiry. Each of these factors carried a higher risk even when considered in the context of the other traits, and risk increased with an increase in the number of characteristics possessed.

Adolescent↗
PubMed1977

Angiosarcoma of the liver: an epidemiologic survey.

Diagnosed from 1970 through 1975, the annual incidence rate for angiosarcoma of the liver among residents of New York State (excluding New York City) was 0.25 per million. A case-control study indicated that direct exposure to arsenic, vinyl chloride (VC), and thorium dioxide was a significantly important factor in the etiology of this disorder (P less than 0.02). Direct exposure to these chemicals could not be demonstrated for 19 (73%) of the 26 study patients. The fact that 5 of these patients lived nearer to VC fabrication or polymerization plants than did their matched controls lent some support to the hypothesis that indirect modes of exposure, not specifically related to occupation, might be important in the etiology of this disorder.

Adolescent↗
PubMed1977

The simplification of a clinical data base: application to gallstone patients.

In patients with gallstones, recommendations for cholecystectomy depend on evidence of abnormality in the cholecystogram. Symptoms and signs, usually related as a syndrome, are employed to identify patients who should have a cholecystogram. Triplet combinations of clinical data from gallstone patients and controls were examined to find which combination was the best discriminator between diseased and non-diseased, and between those who should be investigated radiologically and those who need not. The cholecystogram was confirmed as the best overall discriminator, but right costal margin pain by itself was as efficient as any triplet. The performance of a cholecystogram on all patients with right costal margin pain is as efficient a system for identifying patients with gallstones as the consideration of any quantity of clinical data.

Cholecystography↗
PubMed1977

In-vitro studies of gallstone dissolution: the effect of added heparin in bile salt solutions.

The dissolving effect of four bile salt solutions (sodium cholate, sodium taurocholate, sodium deoxycholate and sodium chenodeoxycholate) upon gallstones was tested in an in-vitro preparation, using 226 stones from 38 patients. The effect of each solution was measured by recording weight loss in the gallstone at the end of a ten-day period of immersion in the bile salt solution. Sodium deoxycholate and sodium chenodeoxycholate produced the greatest average weight loss in the groups of stones tested with pure bile salt solutions, but the addition of heparin to solutions of sodium cholate and sodium deoxycholate produced a significant increase in weight loss in these solutions. This effect of heparin in the presence of bile salts, in comparison with the failure of heparinized saline to induce weight loss in gallstones, is discussed. Sodium chenodeoxycholate cannot be recommended for clinical use on the grounds of its toxicity, and in view of the possible toxicity of sodium deoxycholate it is concluded that a combination of sodium cholate with heparin is the optimum solution for the dissolution of retained intraduct calculi in vivo.

Bile Acids and Salts↗
PubMed1976

A brief review of the concepts related to certain modern analytical methods and their use in medical science.

A number of sophisticated analytical methods are avialable in Australia and are in current use in medical research. Some basoc knowledge is required to understand the concepts behind their use, and expertise is necessary for interpretation of the results. In this brief review, the principles behind a number of modern analytical methods such as emission spectroscopy, electron microprobe, mass spectroscopy, infra-red spectroscopy, and X-ray diffraction, have been described in simple terms. These techniques may be used in the analysis of biological specimens. a number of illustrations of their use in medical research have been given.

Chemistry Techniques, Analytical↗
PubMed1976

Formal presentation at a scientific meeting.

The giving of a ten minute scientific communication is an art form peculiar to researchers who frequently fail to research the technology required for the performance. Careful selection of the scientific material to be included, the audio-visual aids to support it, and adequate rehearsal before presentation to a critical audience are vital to the success of the presentation.

Communication↗
PubMed1975

Early jaundice after pig liver transplantation.

Of a series of pigs surviving orthotopic liver allotransplantation with end-to-end anastomosis of the bile duct, 70% were noted to be jaundiced at the end of the first week after transplantation. Seven animals in a subsequent series were investigated biochemically, but operative cholangiography, and by liver biopsy seven days after transplantation, when the jaundice was maximal. There was definite cholangiographic obstruction in only one animal, and this finding was subsequently confirmed at autopsy. This was also the only animal in which bile culture was positive. Jaundiced animals appeared to have more marked histological evidence of rejection than non-jaundiced ones. The jaundice was probably a result of transient rejection and usually resolved spontaneously without immunosuppression.

Animals↗