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Biomedical subjects

J A Butler

Publications and source records attributed to J A Butler.

At least 19 recordsLinked to original sources
PubMed1997

Dietary selenium increases selenoprotein W levels in rat tissues.

Two experiments were conducted to evaluate the influence of dietary selenium (Se) on tissue levels of selenoprotein W (Se-W) in rats. Se dependent glutathione peroxidase (GPX) activity and Se levels were also determined for comparative measurements. In the first experiment, rats were fed a basal diet deficient in Se or supplemented with either 0.1 or 4.0 mg Se (as selenite) per kg diet for 6 wk. Se-W levels were significantly higher in muscle, spleen and testes of rats fed 0.1 mg Se per kg diet compared to those fed the deficient diet (controls), and those fed 4.0 mg Se per kg diet had significantly higher levels in muscle, brain and spleen (P < 0. 05) than those fed 0.1 mg Se per kg diet. No further increases, however, occurred in the tests. There was a significant increase (P < 0.05) of mRNA encoding Se-W in muscle with each increase of dietary Se. In the second experiment rats were fed the basal diet or this diet plus 0.01, 0.03, 0.06, 0.1, 1.0, 2.0 or 4.0 mg Se per kg diet. The levels of Se-W in muscle did not increase (P < 0.05) until 0.06 mg Se per kg diet were fed to rats. A very marked increase (P < 0.05) occurred when 1.0 mg Se per kg diet was fed with no further increases with higher levels. There was a linear increase of Se-W in brain (r = 0.89) and spleen (r = 0.98) with the Se concentration in the diet up to 0.1 mg Se per kg where a plateau was reached. The testes showed a different pattern in that a very marked increase (P < 0.01) occurred when only 0.01 mg Se per kg diet was fed where an inflection was reached. Except for muscle, GPX activities reached a plateau in all tissues when diets containing 0.06 to 0.1 mg supplemental Se per kg were fed. The Se concentration in these tissues increased at a linear rate with the Se concentration in the diets up to 0.1 mg Se per kg where it continued to rise at a different rate. The results indicate that in rats, the regulation of Se-W by Se is different for various tissues and differs from that for GPX.

Administration, Oral↗
PubMed1997

Hormone replacement therapy and the risk of breast lesions that predispose to cancer.

To determine whether postmenopausal individuals being treated with hormone replacement therapy (HRT) have an increased risk for lesions that predispose to breast cancer, 156 women with benign breast lesions were retrospectively studied. Their ages ranged from 43 to 88. Each patient underwent a breast biopsy from 1991 to 1995. It was determined from chart review whether each of these patients had been treated with HRT. Fifty-seven of these patients had a biopsy finding that predisposed the patient to future breast cancer. The predisposing lesions included sclerosing adenosis, intraductal papilloma, and epithelial hyperplasia with atypia. Of these 57 patients, 36 (63%) were being treated with HRT. Only 30 of the 99 patients (30%) with nonproliferative lesions were treated with HRT (odds ratio, 3.9; P < 0.0005). On the basis of the results of this study, we believe that the use of HRT may promote lesions that predispose to cancer. This suggests that patients treated with HRT require vigilant surveillance by way of examination and mammography.

Adult↗
PubMed1994

Uptake of selenite, selenomethionine and selenate by brush border membrane vesicles isolated from rat small intestine.

The uptake of selenite, selenate and selenomethionine (SeMet) was performed with brush border membrane vesicles (BBMV) prepared from rats fed selenium-deficient and supplemented diets. At equilibrium (60 min), the uptake of 75Se from [75Se]selenite ranged from 16.5 to 18.9 nmol mg-1 protein. There was a curvilinear relationship in the uptake of selenite over a concentration range of 10-1000 microM. About 2 nmol mg-1 protein was obtained with selenomethionine (SeMet) which occurred between 90 and 180 s. In contrast to selenite, there was a linear relationship in the initial uptake of SeMet over a concentration range of 10-1000 microM. The uptake of selenate was approximately 50-fold lower than selenite, reaching 350 pmol mg-1 protein. Dietary selenium level had no effect on the rate of 75Se accumulation by BBMV. Dramatic differences are found in the uptake and binding of selenium by BBMV incubated with different selenocompounds.

Animals↗
PubMed1994

Goblet cell carcinoid of the appendix.

BACKGROUND: Over the past 15 years, a variant of appendiceal carcinoid has been recognized which is not widely known to the general surgeon. This tumor, variously labeled adenocarcinoid or goblet cell carcinoid, has a more aggressive natural history than classic appendiceal carcinoids and requires a different surgical approach. PATIENTS AND METHODS: A survey of the tumor registries of 10 hospitals identified 7 female and 2 male patients with goblet cell carcinoid of the appendix between 1983 and 1993. The clinical data of these patients were reviewed. RESULTS: Median age was 58 years (range 31 to 73). Clinical presentation followed two distinct patterns: acute onset suggestive of appendicitis or chronic symptoms associated with a pelvic mass. In no case was the diagnosis suspected preoperatively or established intraoperatively. Four patients with discrete distal appendiceal tumors treated with appendectomy are alive without evidence of disease 2 to 11 years since their diagnoses. The 5 patients with diffuse appendiceal involvement all had intra-abdominal metastases. Four are dead of disease at intervals from 5 months to 2 years postdiagnosis. CONCLUSIONS: Goblet cell carcinoids are a distinct clinical and pathologic entity with variable malignant potential. Patients with diffuse appendiceal involvement require aggressive surgery as part of multimodal therapy.

Adult↗
PubMed1994

Endoscopic ultrasound-guided fine needle aspiration of pancreatic carcinoma.

Endoscopic ultrasound (EUS) is reported to be the single best modality for visualizing small pancreatic carcinomas. Whereas tissue diagnosis by fine needle aspiration (FNA) can be performed with computed tomography (CT) or transabdominal ultrasound guidance, the diagnostic accuracy is limited by the ability of these modalities to visualize the lesion. Real time EUS-guided fine needle aspiration has recently been reported as a new diagnostic modality. The application of EUS-guided FNA in the diagnosis of small pancreatic carcinoma has not been reported. We present a case in which transduodenal EUS-guided FNA was successful in establishing a definitive tissue diagnosis of pancreatic carcinoma in a 1.6-cm lesion in the head of the pancreas. This case along with a review of the literature highlights the great potential of this new modality in the diagnosis of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1993

Determination of the distribution of selenium between glutathione peroxidase, selenoprotein P, and albumin in plasma.

A chromatographic method is described to determine the distribution of selenium between selenoprotein P, glutathione peroxidase (GSH-Px), and albumin in plasma, using two small columns of heparin-Sepharose and reactive blue 2-Sepharose linked together in tandem. One milliliter of plasma was diluted to 12 ml with 0.02 M sodium phosphate buffer, pH 7.0 (the equilibration buffer), applied to the heparin-Sepharose column, and eluted at a flow rate of 30 ml per hour. GSH-Px was not retained by either of these columns but selenoprotein P was retained by heparin-Sepharose and albumin by reactive blue. After the two columns were separated, selenoprotein P was eluted with heparin from heparin-Sepharose and albumin eluted from reactive blue with high salt. Analytical work confirmed the presence of selenoprotein P, GSH-Px, and albumin in the respective fractions. When rats were injected with 75Se as either selenite or selenomethionine most of the radioactivity was incorporated into the selenoprotein P fraction, with the next greatest amount into GSH-Px, and the least amount into albumin. Slab gel electrophoresis was used to determine that most of the selenium in each of the three fractions was associated with each of these selenium containing proteins. This method indicated that the majority of the selenium in plasma is associated with selenoprotein P, and the only time this was found not to be true was with high levels of dietary selenomethionine.

Animals↗
PubMed1993

Omphalocaval shunt: an alternative procedure for portal decompression.

We report a case in which umbilical vein was used to construct an omphalocaval shunt in a patient with a long history of alcoholic liver disease and recurrent esophageal and gastric variceal bleeding episodes. The indication for the choice of this procedure included the presence of dense adhesions in the porta hepatis, arteriographic documentation of continuity with the portal venous system, and an umbilical vein 12 mm in internal diameter. The hypertensive portal system was successfully decompressed and proved patent 6 months postoperatively.

Adult↗
PubMed1993

Long-term supplementation with selenate and selenomethionine: selenium and glutathione peroxidase (EC 1.11.1.9) in blood components of New Zealand women.

Thirty-three New Zealand women aged 18-23 years received daily for 32 weeks, 200 micrograms Se as Se-enriched yeast (selenomethionine), or brewer's yeast mixed with selenate, or no added Se (placebo) in a double-blind trial. Se supplementation raised (P = 0.001) platelet glutathione peroxidase (EC 1.11.1.9; GSHPx) activity, and also Se and GSHPx in whole blood, erythrocytes and plasma. Selenomethionine was more effective in raising blood Se concentrations than selenate, but both were equally effective in raising GSHPx activities in whole blood, erythrocytes and plasma, indicating a similar bioavailability for the two forms. These observations and those of gel filtration studies of erythrocytes and plasma proteins reported elsewhere (Butler et al. 1991) are consistent with the incorporation of Se from selenomethionine into a general tissue protein pool while selenate is directly available for GSHPx synthesis, and explain the poorer correlation between Se and GSHPx in individuals with higher Se status. However, selenate raised platelet GSHPx activities to a greater extent than did selenomethionine suggesting some other effect of selenate on platelets which needs further investigation. A response of GSHPx activity in these New Zealand subjects indicates that their dietary Se intake is insufficient to meet recommended intakes based on the criterion of saturation of GSHPx activity, and could reflect a marginal Se status. The level of blood Se necessary for saturation of GSHPx of about 100 ng Se/ml whole blood confirms observations in earlier studies.

Adolescent↗
PubMed1992

Guidelines for surgical residents' working hours. Intent vs reality.

To comply with voluntary California medical school guidelines, our general surgery residency program reduced in-house call to 1 in 4 nights, and scheduled a 72-hour work-week. We assessed the effectiveness of these changes by prospectively surveying the actual working hours of surgical house staff through completion of a daily schedule for 1 month. Actual in-hospital hours averaged 98 per week, significantly exceeding the scheduled hours, and were greater for interns (100 hours) and junior residents (97 hours) than for chief residents (95 hours). Twenty hours (22%) of nonconference waking hours were spent on so-called scut work. Significant reduction of intern work hours could be accomplished by expansion of ancillary care, allowing more time for direct patient care. The effect on senior house staff hours would be less dramatic but might be sufficient to bring hours into compliance with proposed limits.

General Surgery↗
PubMed1992

Use of teaching methods within the lecture format.

A survey was carried out at Dorset House School of Occupational Therapy, Oxford, into the perceived effectiveness of different teaching methods used within the lecture format in the Human Biology Courses for Year 1 and Year 2. Results showed that the traditional, didactic lecture was perceived by the students as the least effective method used, yet by involving the students actively within the lecture time the format was enhanced and was regarded as a more effective teaching/learning tool. Experimental tasks and learning packages used within the lecture format were also perceived by the students as effective. Some trends were noted relating to the age of students and the different perceptions of effectiveness of teaching methods. The implication of these results on the planning and financing of courses is discussed.

Adult↗
PubMed1992

Immunohistochemical determination of the estrogen receptor content of gastrointestinal adenocarcinomas.

Recently there have been several reports documenting the presence of estrogen receptors (ERs) in human gastrointestinal (GI) malignancies, raising the possibility that these cancers may be hormonally manipulated. To test this hypothesis, 68 frozen GI tissue specimens were examined for the presence of ERs within the cell nuclei by immunohistochemical staining. There were 51 cancers (25 gastric, 26 colon) and 17 normal tissue specimens (six gastric, 11 colon). Tissue sections 4 to 6 microns thick were incubated with monoclonal antibody H222SP psi, then stained by the peroxidase-antiperoxidase technique for visualization of the ER. The staining was semiquantitatively graded from 0 to 3+ depending on both the intensity of staining and the percentage of cell nuclei stained. A breast cancer specimen known to be strongly positive for the ER was used as a positive control. The 30 male and 21 female cancer patients had a median age of 59 years. All tumors were adenocarcinomas. Eight per cent of the gastric cancers were poorly differentiated, while 94 per cent of the colon cancers were moderately well to well differentiated. Using weak staining of at least 20 per cent of the cell nuclei as the minimum requirement for an ER positive tumor (1+, 0/51 tumors and 0/17) normal specimens were positive for ER. Only three out of 25 (12%) gastric tumors, and two out of 26 (8%) colon tumors demonstrated any staining; each exhibited weak staining of only five to ten per cent of the tumor nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1992

Perceived mistreatment of graduating dental students: a retrospective study.

This study assessed types and sources of perceived mistreatment among graduating dental students. A total of 38 of 46 (83 percent) students anonymously completed a mistreatment questionnaire. All 38 students perceived experiencing at least one type of mistreatment from some source and reported an average of about 35 separate incidents. Psychological mistreatment was most frequent with physical mistreatment reported relatively infrequently. Classmates and clinical faculty were the most frequent sources of mistreatment. Sexual harassment was perceived by about one-third of the students. The potentially adverse effects of perceived mistreatment were discussed with a view to improving dental education through an emphasis on stress management, environmental change, and self-responsibility for health designed to enhance the personal growth of each dental student.

Adult↗
PubMed1991

Presence of an SH2 domain in the actin-binding protein tensin.

The molecular cloning of the complementary DNA coding for a 90-kilodalton fragment of tensin, an actin-binding component of focal contacts and other submembraneous cytoskeletal structures, is reported. The derived amino acid sequence revealed the presence of a Src homology 2 (SH2) domain. This domain is shared by a number of signal transduction proteins including nonreceptor tyrosine kinases such as Abl, Fps, Src, and Src family members, the transforming protein Crk, phospholipase C-gamma 1, PI-3 (phosphatidylinositol) kinase, and guanosine triphosphatase-activating protein (GAP). Like the SH2 domain found in Src, Crk, and Abl, the SH2 domain of tensin bound specifically to a number of phosphotyrosine-containing proteins from v-src-transformed cells. Tensin was also found to be phosphorylated on tyrosine residues. These findings suggest that by possessing both actin-binding and phosphotyrosine-binding activities and being itself a target for tyrosine kinases, tensin may link signal transduction pathways with the cytoskeleton.

Actins↗