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Biomedical subjects

J A Butler

Publications and source records attributed to J A Butler.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1991

Small bowel obstruction in patients with a prior history of cancer.

To assess the efficacy of operative and nonoperative therapy of small bowel obstruction (SBO) in patients with a previous diagnosis of cancer, a review of 54 cases was carried out. The 32 men and 22 women had a mean age of 58 years. At presentation with SBO, 26 patients (48%) had known recurrent cancer. Forty patients were initially treated nonoperatively; 11 (28%) had resolution of their SBO after a mean of 7 days of nasogastric suction. Five of 11 patients developed recurrent SBO prior to death. Thirty-seven patients underwent laparotomy, 14 on the day of admission and 23 after failure of nasogastric suction. Twenty-five of 37 (68%) had obstruction due to recurrent carcinoma. Small bowel obstruction due to recurrent cancer occurred earlier (21 +/- 5 months) than SBO from benign causes (61 +/- 18 months; p < 0.01). Mean survival for patients with malignant obstruction (5 +/- 1 month) was significantly shorter than for those with benign obstruction (50 +/- 10 months; p < 0.001). The 30-day and in-hospital mortality rates for the 25 surgically treated patients with malignant SBO were 24% and 28%, respectively; in 9 of 25 (36%), the obstruction failed to fully resolve. The only factor predictive of in-hospital mortality was obstruction secondary to cancer (p < 0.05). The median posthospital survival for surgically treated patients with malignant SBO was only 2.5 months. We conclude that: (1) patients should be given an initial trial of nonoperative therapy; (2) patients with no known recurrence or a long interval to the development of SBO should be aggressively treated with early surgery if nonoperative treatment fails; and (3) for patients with known abdominal recurrence in whom nonoperative therapy fails, the results of surgical palliation are grim. Innovative approaches are needed to maximize palliation while also limiting morbidity and mortality.

Adult↗
PubMed1991

Angiotensin alteration of drug uptake in an experimental model of hepatic metastases.

To evaluate the use of angiotensin-II (A-II) as a means of improving results with intra-arterial infusions of hepatic tumors, 32 New Zealand white rabbits underwent perfusion of VX-2 hepatic implants. Tritium-labeled fluorodeoxyuridine [( 3H]FUDR) was administered via peripheral ear vein in 9 control rabbits (iv), via the hepatic artery in 12 rabbits (HA), and following a constant infusion of A-II in the remaining 11 rabbits (HA/A-II). Biopsies of tumor and normal hepatic parenchyma were taken and tissue levels of FUDR measured. Hepatic artery infusions, both with and without A-II, resulted in a significantly greater tumor uptake of FUDR than the iv infusions (P less than 0.001). More importantly, the tumor/liver ratio of FUDR uptake was significantly greater in the HA/A-II group (3.40) than that in the HA without A-II (0.98) group (P less than 0.001). This difference is due to the decreased FUDR uptake by normal hepatic parenchyma in rabbits undergoing A-II infusion; tumor drug uptake is similar for both groups. We conclude that the addition of angiotensin II to hepatic artery infusional chemotherapy significantly improves the tumor/liver ratio of drug uptake in this experimental model of hepatic metastases.

Angiotensin II↗
PubMed1991

MR and CT imaging of ethanol-treated liver tumors in an animal model.

To characterize the radiographic appearance of liver lesions over time following ethanol injection, seven New Zealand white rabbits underwent surgical implantation of small fragments of VX-2 carcinoma within the liver. Upon reaching 1 cm in diameter, a tumor nodule was directly injected with absolute ethanol. Another nodule in the same animal was injected with saline as a control. Imaging was performed 6-24 days after the injections by high resolution CT and MRI, and correlation obtained with the pathologic specimens. Long TR spin-echo MR sequences were found to characterize the ethanol-treated regions of liver most accurately. Liver tissue infarcted by alcohol could be differentiated from tumor and necrosis by virtue of its short T2 relaxation value. There were no distinguishing features by other imaging techniques between the ethanol-treated and control tumor nodules. Peripheral contrast enhancement was demonstrated in both, corresponding to fibrous tissue around the ethanol-injected regions, and to viable tumor in the case of controls.

Animals↗
PubMed1991

Selenium distribution in blood fractions of New Zealand women taking organic or inorganic selenium.

Three groups of 11 New Zealand women each received, for 32 wk, yeast tablets with no added selenium (placebo) or 200 micrograms Se/d in tablets either as selenate or as selenium-enriched yeast (SeMet) in a double-blind selenium trial. Plasma and erythrocyte (RBC) samples were collected bimonthly. Gel filtration of plasma from women taking SeMet revealed two major selenium-containing peaks with most of the selenium in the second peak. In contrast, the first peak contained most of the selenium in plasma from women taking selenate. Chromatography of RBC lysates indicated that the majority of the selenium was with hemoglobin (Hb) in women taking SeMet but was about equally distributed between glutathione peroxidase (GSH-Px) and Hb in women taking selenate. The percentage of selenium associated with GSH-Px was found to be greater in RBCs and plasma of women taking selenate than of those taking SeMet.

Adult↗
PubMed1991

Ethanol injection of hepatic tumors.

To assess the efficacy of intratumoral injections of absolute ethanol in the treatment of hepatic tumors, 18 New Zealand White rabbits underwent implantation of two 1-mm3 fragments of the VX-2 carcinoma. The animals were reexplored 2 weeks postimplant and the tumors measured. One nodule was treated by intratumoral injections of 2.28 +/- 0.72 mL of absolute ethanol; the second was injected with an equal amount of normal saline. The animals were sacrificed 4 weeks postimplant, and the tumors were measured and microscopically examined. On gross inspection, tumor size, expressed as the product of the largest and smallest diameters, was 4.59 +/- 3.4 cm2 for the ethanol-injected tumors vs 6.73 +/- 2.1 cm2 for the saline-treated nodules (p = .01). Histologic sections through the largest tumor diameter were microscopically examined using a computerized image analyzer. The mean cross-sectional area of viable tumor was 0.51 +/- 0.3 cm2 for the ethanol-treated nodules vs 2.01 +/- 0.5 cm2 for the saline-treated nodules (p less than .001). Contrast-enhanced CT and MRI studies were able to provide valuable information in terms of tissue characterization, which will be useful in differentiating viable tumor from necrotic tumor and infarcted liver. We conclude that intratumoral ethanol injection inhibits growth of liver tumors in this experimental model and deserves further study.

Animals↗
PubMed1991

Influence of arsenic on selenium metabolism and glutathione peroxidase activity in rats.

Arsenic accumulated to the greatest extent in blood followed in decreasing order by kidney, hair and liver in rats fed with various levels of arsenic. Within the intracellular fractions of the liver, arsenic accumulated to the greatest extent in the nuclear fraction, followed by cytosol, mitochondria and microsomes in decreasing order. Increasing arsenic significantly increased the deposition of 75Se-selenite in heart and testis but had no effect in blood, liver, spleen or kidney and significantly increased the excretion of 75Se in feces with a concomitant decrease in urinary excretion. Within the hepatic intracellular fractions, arsenic significantly altered only the 75Se content of the microsomes. Arsenic had no effect upon the glutathione peroxidase activities in blood, kidney or testes, but depressed this activity and the stable selenium content in liver.

Animals↗
PubMed1990

Accuracy of combined clinical-mammographic-cytologic diagnosis of dominant breast masses. A prospective study.

Excisional biopsy is considered a mandatory part of the workup for patients with dominant breast masses. To evaluate the efficacy of a combined physical, mammographic, and fine-needle aspiration cytologic examination, 113 women were prospectively evaluated. Breast masses were listed as either benign or suspicious/malignant. All patients underwent a subsequent biopsy. Fifty-two (46%) of 113 patients had a malignant mass. The sensitivity and specificity of the individual tests were as follows: 96% and 66% for the physical examination; 94% and 73% for the mammographic examination; 90% and 93% for the fine-needle aspiration cytologic examination. For the 86 patients who underwent all three studies, the 25 patients with benign test results on all three examinations had a benign pathologic result. One (6%) of 18 patients with a single suspicious/malignant test result had cancer, 9 (64%) of 14 patients with two suspicious/malignant test results and 28 (97%) of 29 patients with three suspicious/malignant results also had breast cancer. We conclude that the combined triad of physical, mammographic, and fine-needle aspiration cytologic examinations is highly accurate in the diagnosis of breast masses, and patients in whom all three examination results are benign can be safely observed, obviating the need for an open biopsy.

Adult↗
PubMed1990

The effect of interplay interval on adjunctive behavior in humans in a game-playing situation.

Thirty-seven undergraduate students played two consecutive games of backgammon where manipulated interplay intervals were either 10, 22.5, 45, or 90 sec in length. When visual access to the opponent's play was blocked by a curtain during the second game, rates of movement, drinking, and eating increased over baseline rates prevailing in the first game. Grooming rate was not affected. Functions relating behavior rate to interplay interval were not bitonic for any of the behaviors; however, response distributions for drinking demonstrated postplay peaks at each interplay interval. Problems of classifying human behaviors into adjunctive versus faculatative categories were discussed.

Adolescent↗