Biomedical subjects

J A Butler

Publications and source records attributed to J A Butler.

At least 55 records · Page 3Linked to original sources

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↗

PubMed1990

Evaluation of women with possible appendicitis using technetium-99m leukocyte scan.

The authors evaluated the use of technetium-99m albumin colloid white blood cell (TAC-WBC) scan in women with possible appendicitis. One hundred and nine women underwent 110 TAC-WBC scans. One woman had a second scan on a separate admission and was considered two individual patients in the analysis. Twenty-six women had appendicitis, 10 of whom had a perforated appendix at surgery. The TAC-WBC scan was indeterminate (abnormal but nondiagnostic for appendicitis) in 52 women (47%), nine of whom had appendicitis. Fifty-eight scans were read as positive or negative for appendiceal pathology. There were 16 true positives, 5 false positives, 36 true negatives, and 1 false negative. The predictive value of a positive scan was 76%, and the predictive value of a negative scan was 97%. The TAC-WBC scan was positive in 62% of patients with appendicitis and negative in 43% of the patients without appendicitis resulting in an overall accuracy of 47% in the 109 women. The main value of TAC-WBC scan in women with possible appendicitis is its high negative predictive value and the main problem with the TAC-WBC scan is its high indeterminate rate.

Abdominal Pain↗

PubMed1990

Metabolism of selenite and selenomethionine in the rhesus monkey.

Female rhesus monkeys were fed a commercial monkey diet and given selenium (Se) as either selenite or selenomethionine (SeMet) in the drinking water for 11 mo. Muscle and liver biopsies were taken initially and at the end of the experiment for determination of Se levels and glutathione peroxidase (GPX) activity. Blood was collected at monthly to bimonthly intervals, and the plasma and erythrocytes were subjected to gel filtration to determine the distribution of Se among proteins of various molecular weights. At the end of the experiment, there was significantly more Se in liver, muscle and hair from the monkeys given SeMet than in tissues from those given selenite, but there were no differences in liver or muscle GPX activity between the two treatment groups. The erythrocyte and plasma Se levels were significantly higher in the monkeys given SeMet than in those receiving selenite, but there were no differences in the GPX levels between these groups. About 68% of erythrocyte Se was associated with GPX in monkeys given selenite whereas only 34% was associated with GPX in those administered SeMet. The correlation coefficient for blood Se level and erythrocyte GPX activity was 0.92 in monkeys given selenite but only 0.37 in those given SeMet. Gel filtration of plasma revealed only one Se peak for plasma from the monkeys given selenite but at least two major Se peaks for plasma from monkeys receiving SeMet. The possible implications of these results for humans are discussed, including the reasons for poor correlations of GPX activity and blood Se levels.

Animals↗

PubMed1990

Palliation for nonpancreatic malignant obstruction of the biliary tract.

To determine the best palliation for nonpancreatic malignant obstruction of the biliary tract, we analyzed 36 patients with unresectable tumors who were treated from 1970 to 1986. Eleven men and 25 women were treated for 12 cholangiocarcinomas, ten carcinomas of the gallbladder, two advanced ampullary tumors and 12 metastatic tumors. Ten of the patients underwent biliary-enteric bypasses; 18 had stents placed, 11 operatively and nine percutaneously. The remaining eight patients received chemotherapy, radiation therapy or no treatment. Median survival time for patients was 209 days after discharge. Survival was not significantly prolonged for patients with bypass versus those with stents. Achieving and maintaining a bilirubin level of less than or equal to 4 were correlated with survival time (p less than 0.01, p less than 0.001). All ten patients with a bypass versus nine of 18 patients with a stent achieved a bilirubin level of less than or equal to 4 milligrams per deciliter (p less than or equal to 0.01). A multivariate analysis was done using 18 of 27 variables identified by univariate analysis. Albumin was found to be the primary predictor of over-all and hospital-free survival time and was a co-predictor of prolonged maintenance of low bilirubin levels along with biliary-enteric bypass. Placement of a stent was the only predictor of the number of episodes of sepsis and bypass was among the few predictors of length of hospitalization and of over-all morbidity (it was negatively correlated). We concluded that biliary-enteric bypass is the only effective means of palliation in that it improves the quality of life by maintaining low bilirubin levels and minimizing septic complications. Albumin is a strong predictor of survival and maintenance of low bilirubin values and should be a major factor in deciding which patient should undergo a bypass procedure.

Adenoma, Bile Duct↗

PubMed1990

Evaluation of children with possible appendicitis using technetium 99m leukocyte scan.

We evaluated the use of technetium 99m albumin colloid white blood cell (TAC-WBC) scan in 33 children with possible appendicitis. Ten children had appendicitis, four of whom had perforated their appendix at the time of surgery. Children with appendicitis differed from children without appendicitis in the incidence of right lower quadrant rebound tenderness (60% vs 17.4%), and white blood cell count (X10(3)/mm3) (14.0 + 1.9 vs 10.7 +/- 1.0). TAC-WBC scans were interpreted as either positive, negative, or indeterminate for appendiceal pathology. Twenty-five children had positive or negative scans for appendiceal pathology. There were 7 true positives, 2 false positives, 16 true negatives, and 0 false negatives. This resulted in a sensitivity of 100%, a specificity of 89%, an accuracy of 92%, a positive predictive value of 78%, and a negative predictive value of 100%. The TAC-WBC scan was indeterminate (abnormal but nondiagnostic for appendicitis) in eight children (24%), three of whom had appendicitis. The main values of TAC-WBC scan in our study of children with possible appendicitis were that it could be used emergently, it was abnormal in 100% of children with appendicitis, and it had a high negative predictive value (100%). The main limitation of TAC-WBC scan in our study was that it was indeterminate for appendiceal pathology in 24% of children. We recommend that TAC-WBC scan be used in children with possible appendicitis because it may allow outpatient management of up to 48%.

Adolescent↗

PubMed1989

Value of measuring hormone receptor levels of regional metastatic carcinoma of the breast.

To assess the value of measuring the estrogen- and progesterone-receptor content of metastatic nodal disease, 38 women with node-positive breast cancer were prospectively evaluated. Receptor content of the primary tumor and a pathologically confirmed positive node were measured simultaneously using a dual-isotope, dextran-coated, charcoal-binding assay. A receptor content of greater than or equal to 10 fmol/mg of cytosol protein was considered positive for both the estrogen-receptor and progesterone-receptor assays. Overall concordance between the primary tumors and the nodal metastases was 82% (31/38 patients) for the estrogen-receptor measurements and 84% (31/37 patients) for the progesterone-receptor measurements. Paired receptor levels were significantly correlated: r = .745 for the estrogen-receptor measurements and r = .805 for the progesterone-receptor measurements. Despite this correlation, 6 (25%) of 24 patients with an estrogen receptor-positive primary tumor had an estrogen receptor-negative nodal metastasis. Four (20%) of 20 patients with a progesterone receptor-positive primary tumor had a progesterone receptor-negative nodal metastasis. Six (24%) of 25 patients with tumors labeled as hormonally sensitive on the basis of the receptor content of the primary tumor had receptor-negative nodal disease. In reflecting the hormonal status of the more aggressive elements of the primary tumor, receptor levels of metastatic nodes may provide more useful information than the levels of the primary tumor as a guideline for further therapy.

Breast Neoplasms↗

PubMed1989

Analysis of effect of age on synthesis of specific proteins by hepatocytes.

The effect of age on the synthesis of specific proteins by hepatocytes was studied in Fischer F344 rats using two-dimensional polyacrylamide gel electrophoresis. Almost all proteins synthesized by hepatocytes from young rats were synthesized by hepatocytes isolated from old rats. Of over 500 proteins visually compared by two-dimensional polyacrylamide gel electrophoresis, only 11 proteins were observed to disappear and/or appear consistently with increasing age. The rates of synthesis of 36 randomly chosen proteins were quantified. Interestingly, the synthesis of 35 of the 36 proteins decreased between 5 and 30 months of age. The decrease in protein synthesis varied (15% to 70%) from one protein to another; i.e., a heterogeneity was observed in the age-related decrease in the synthesis of proteins. The age-related decrease in protein synthesis was statistically significant for 53% of the proteins studied. The total decrease in the rate of synthesis of all 36 proteins studied was 40% between 5 and 30 months of age, which is essentially the same as the decrease in total protein synthesis by suspension of hepatocytes isolated from 5- and 30-month-old rats. The results of this study demonstrate that the mechanism underlaying aging is different from development, which is characterized by a major change in the species of proteins synthesized by a cell.

Aging↗