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Biomedical subjects

A Allen

Publications and source records attributed to A Allen.

At least 181 records · Page 10Linked to original sources
PubMed1992

Mucus glycoprotein biosynthesis in the human gall bladder: inhibition by aspirin.

Aspirin, which inhibits mucin secretion in the gastrointestinal tract prevents gall stone formation in animals and may reduce gall stone recurrence in man. This study examines the effect of aspirin on mucin synthesis in human gall bladder explants. Two hundred explants were cultured with 3H-glucosamine (74 kBq/ml) for 24 hours at 37 degrees C. Mucin and other glycoproteins were isolated by papain digestion (72 hours) and exhaustive dialysis (144 hours) to remove non-incorporated radioactivity and digested protein. 3H-glucosamine was readily incorporated into glycoprotein. Pooled gall bladder explants were fractionated on a CsCl density gradient and by gel filtration on Sepharose 2B and 4B to confirm that >90% radioactivity was incorporated into mucin. Acetylsalicylic acid (230-666 micrograms/ml) significantly reduced total 3H-glucosamine incorporation (43-89%), p<0.01 (unpaired t test). Diclofenac (125-1250 micrograms/ml), similarly reduced incorporation by 45-97% p<0.001 (unpaired t test). Inhibition of mucin glycoprotein biosynthesis was irreversible with both drugs. Analysis of pooled samples on Sepharose 4B showed abolition of radioactive incorporation into mucin but no effect on incorporation into low molecular weight glycoprotein material (10% of total incorporation). This study provides a method for measuring human gall bladder mucin synthesis and shows its irreversible inhibition by acetylsalicylic acid and diclofenac at concentrations compatible with a therapeutic dose.

Aspirin↗
PubMed1992

Inhibition of human gall bladder mucus synthesis in patients undergoing cholecystectomy.

Hypersection of gall bladder mucus is associated with gall stone formation in animal models. Aspirin inhibits both mucus synthesis and secretion, prevents gall stone formation in animals and reduces gall stone recurrence in man after dissolution therapy. Mucus biosynthesis in human gall bladder mucosal explants is inhibited by aspirin in vitro. We have studied the effects of aspirin in vivo. Fifty five patients with functioning gall bladder and stones have been randomised, 27 to group 1 (aspirin EC 300 mg once daily for seven days before cholecystectomy) and 28 to group 2 (controls). Gall bladder bile composition was analysed and mucus synthesis rates measured using 3H-glucosamine incorporation into mucosal explants cultured for 24 hours. Patient age, sex, and gall bladder histology were similar in both groups. There were no differences in stone composition, gall bladder bile calcium concentration, cholesterol saturation and cholesterol nucleation time. The mean 3H-glucosamine incorporation in aspirin treated patients was 1347 fmol/g wet weight as compared with 2008 fmol/g wet weight in controls (95% confidence interval 222-1100, p<0.005, unpaired t test). This reduction in biosynthesis was associated with gall bladder bile mucus concentrations of 7.6 mg/ml in patients and 7.1 mg/ml in controls (ns). Treatment with aspirin led to a significant reduction in mucus biosynthesis by the gall bladder mucosa. This action is consistent with a role for aspirin in the prevention of gall stones.

Adult↗
PubMed1992

Medical device reporting: a new challenge for perioperative nurses.

A variety of illnesses and other complications have been attributed to problems resulting from use of medical devices, implants, and instruments. A new law has implications for all health care facilities using medical devices. The Safe Medical Devices Act (SMDA) of 1990 mandates the reporting of complications related to the use of medical devices to the United States Food and Drug Administration. Reporting requirements of the SMDA could challenge the efficiency of information systems in health care facilities and add to the responsibilities of staff nurses. In the following article, the author discusses some implications of the new law.

Equipment Safety↗
PubMed1992

New opportunities for Americans with disabilities.

Historically, individuals with disabilities have been isolated and segregated. Physical and psychological barriers left them significantly disadvantaged, politically powerless, and without legal recourse in matters of discrimination. The Americans With Disabilities Act of 1990 is opening doors and promising new opportunities for individuals with disabilities to contribute and participate fully in our society. The author offers an overview of the purpose and major provisions of the act, which compares in scope to the Civil Rights Act of 1964.

Civil Rights↗
PubMed1992

Responding to change in the decade of dilemma.

Virtually every politician seeking public office has proposed a national health care plan. Attempts to reduce the cost of health care have been less than successful. Indeed, cooperative action in dealing with health care problems is unlikely during this election year and probably for some time to come. In the following article the author shares some observations and predictions about the political, economic, social, and educational factors that will influence nursing practice in the 1990s, the decade of dilemma.

Health Services↗
PubMed1992

Equal opportunity in the workplace.

The Equal Employment Opportunity Commission (EEOC) was created by the Civil Rights Act of 1964. The commission encourages voluntary compliance with equal employment opportunity practices, and has authority to investigate complaints alleging discrimination in hiring, firing, wage rates, testing, training, apprenticeship, and other conditions of employment. In October 1991, during the Senate Judiciary Committee hearings, the confirmation of Judge Clarence Thomas for a seat on the United States Supreme Court was placed in jeopardy by a charge of sexual harassment while Thomas was head of the EEOC. This article focuses on aspects of sexual harassment in the workplace, the role of the EEOC, and offers some suggestions for keeping the work environment free of abusive behavior.

Aggression↗
PubMed1992

Advance directives provide answers for tough questions.

Will advance directives provide an effective means of assuring that previously written decisions will be honored by health care providers if the patient becomes incompetent or terminally ill? This and other questions are posed in the following article. The Patient Self-Determination Act of 1990 mandates that all health care providers receiving federal reimbursement for services provide information to each patient and offer the option of executing an advance directive for health care decisions. The author presents an overview of two studies about advance directives as reported in the New England Journal of Medicine.

Advance Directives↗
PubMed1992

Copying could be costly.

Thanks to modern technology, photocopying is quick, easy, and inexpensive. Or is it? One of the largest awards ever made for copyright infringement was levied in a case involving the use of material copied from publications without permission. This article presents a short discussion about US and international copyright protection, fair use, and work for hire. Suggestions for additional information are offered.

Copying Processes↗
PubMed1991

The rheology of pig small intestinal and colonic mucus: weakening of gel structure by non-mucin components.

Mechanical spectroscopy has been used to study the structure and properties of pig small intestinal and colonic adherent mucus gel. Both mucus secretions had properties of viscoelastic gels, but that from the small intestine was substantially weaker in quality. Small intestinal mucus gel was disrupted by acid (pH 1), detergents (bile) and protein denaturants while that from the colon remained stable following these treatments. Concentration of purified colonic mucin produced a gel with the same rheological properties as the native secretion. Purified small intestinal mucin when concentrated produced a stronger gel than the native secretion and, in contrast to the latter, one which was not disrupted by acid or denaturants. The instability of native small intestinal mucus was shown not to be a function of the mucin components (which alone could account for the gel-forming properties), but to arise from the presence of insoluble material largely from sloughed mucosal cells. These studies show (1) that mucus gels from the colon and small intestine have similar mechanical behaviour and properties to those from the stomach and duodenum, and (2) emphasise the caution that should be exercised when interpreting the rheological properties of mucus preparations, particularly with respect to their content of mucosal cellular material.

Animals↗
PubMed1991

Older age and elevated blood pressure are risk factors for intracerebral hemorrhage after thrombolysis.

Intracerebral hemorrhage is an important concern after thrombolytic therapy for acute myocardial infarction, but risk factors are controversial. Accordingly, we assessed risk factors in 107 treated patients of whom 4 had intracerebral hemorrhage. Intracerebral hemorrhage occurred at a mean of 25 hours (range 3.5 to 48) after therapy and was fatal in 2 patients. Significant differences were found between patients with and without intracerebral hemorrhage for age (77 +/- 7 vs 62 +/- 11 years, p less than or equal to 0.01), and initial (161 +/- 23 vs 135 +/- 23 mm Hg, p less than or equal to 0.03) and maximal (171 +/- 30 vs 146 +/- 20, p less than or equal to 0.02) systolic blood pressures. Initial and maximal diastolic blood pressures also tended to be higher (101 +/- 25 vs 86 +/- 16, p less than or equal to 0.07; 104 +/- 24 vs 90 +/- 13, p less than or equal to 0.06). Differences did not achieve significance for comparisons of gender, height, weight, site of infarction, time to therapy, specific thrombolytic agent used, concomitant therapy, interventions and partial thromboplastin time. It is concluded that age (greater than or equal to 70 years) and elevated blood pressure (greater than or equal to 150/95 mm Hg) are important risk factors for intracerebral hemorrhage. The overall balance of benefit and risk of thrombolysis should continue to be assessed by large mortality trials.

Age Factors↗
PubMed1991

Cisplatin and novobiocin in the treatment of non-small cell lung cancer. A Southwest Oncology Group study.

Novobiocin, a commercially available oral antibiotic, inhibits DNA topoisomerase II in a manner shown in cell culture to enhance the cytotoxicity of alkylating agents and cisplatin. Thirty-six patients were entered on a Phase II trial using high-dose cisplatin (100 mg/m2 on days 1 and 8 for four cycles) after steady-state dosing with novobiocin (1000 mg or four 250-mg capsules every 12 hours for six doses, four of which were administered before each dose of cisplatin). One patient remains on study and cannot be evaluated for response. No complete responses were seen. Three patients (8%) had partial responses and an additional patient had an unconfirmed partial response. The median survival time of all patients was just less than 7 months. These results are comparable with those of other concurrent Southwest Oncology Group (SWOG) Phase II and III trials of high-dose cisplatin in non-small cell lung cancer (NSCLC). Novobiocin plasma levels were obtained for three patients and were approximately 50% of the optimal concentration as reported in cell culture for potentiation of cytotoxicity. It was concluded that an optimum test of novobiocin as a modulator of cytotoxicity may require the availability of an intravenous preparation.

Administration, Oral↗
PubMed1991

Pigeon breeders' lung: pigeon intestinal mucin, an antigen distinct from pigeon IgA.

Antigens identified by indirect immunofluorescence staining and specific for sera from patients with pigeon breeders' lung or healthy pigeon breeders, have been isolated from pigeon intestinal mucus. Two antigenic peaks, one pigeon intestinal mucin and the other IgA, were separated by equilibrium centrifugation of water-soluble mucus in a caesium chloride density gradient. Antigenic positive material was identified by a modified double-sandwich ELISA, by inhibition of haemagglutination of turkey erythrocytes and by gel diffusion. Antigenic-positive material co-fractionated on gel-filtration with purified intact and papain digested pigeon mucin, both free of IgA. These studies demonstrate antibodies to two quite different antigens are associated specifically with sera from pigeon breeders, a novel antigen pigeon intestinal mucin and the previously documented pigeon IgA.

Animals↗
PubMed1991

Autoradiographic localization and effects of exogenous radioactively labelled surfactant in the lung of the prematurely delivered fetal rabbit.

Adult rabbit lung surfactant was radioactively labelled with [3H]palmitate and isolated by centrifugation. This material was instilled into the trachea of fetal rabbits prematurely delivered on the 27th gestational day. A similar preparation of unlabelled surfactant was used to measure the effects on pressure-volume characteristics in lungs of 27th day fetuses. Tissue sections were prepared from the lungs of all animals and morphometric and autoradiographic determinations made. Surfactant instillation improved pressure-volume relationships in fetal rabbit lungs. Histologically, although only the middle right lobe seemed to show significant qualitative improvement in expansion after surfactant treatment, quantitative assessment indicated that the surfactant preparation had significantly increased the mean alveolar cross-sectional areas in all three lobes of right lungs. In addition, distribution of autoradiographic grains indicated that 8-25% were located over the alveolar spaces while approximately half this percentage was present over tissue at the level of the alveolus. These results indicate that intratracheal instillation of surfactant supplements the endogenous surfactant at the level of the alveolus.

Animals↗
PubMed1991

Low-glycemic index foods improve long-term glycemic control in NIDDM.

OBJECTIVE: To compare high- and low-glycemic index (GI) diets in the treatment of non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Sixteen subjects with well-controlled NIDDM and normal lipid profile, 10 of whom continued oral hypoglycemic medication, participated in the study. A diet that emphasized low-GI foods (e.g., porridge, pasta) was compared with a high-GI diet (e.g., processed cereals, potatoes). The GI of the low-GI diet was 15% lower than the high-GI diet (77 +/- 3 vs. 91 +/- 1) but otherwise similar in macronutrient composition and fiber, as determined by a 4-day weighed record. The diets were instituted under instruction from a dietitian who visited subjects at home on a weekly basis. Body weight was maintained within 1-2 kg. RESULTS: Glycemic control was improved on the low-GI diet compared with the high-GI diet (statistically significant findings, P less than 0.05). Mean glycosylated hemoglobin at the end of the low-GI diet was 11% lower (7.0 +/- 0.3%) than at the end of the high-GI diet (7.9 +/- 0.5%), and the 8-h plasma glucose profile was lower (area under the curve above fasting 128 +/- 23 vs. 148 +/- 22 mmol.h-1.L-1, respectively). Mean fasting plasma glucose, total cholesterol triglycerides, and lipoproteins did not show important differences. CONCLUSIONS: A low-GI diet gives a modest improvement in long-term glycemic control but not plasma lipids in normolipidemic well-controlled subjects with NIDDM.

Blood Glucose↗
PubMed1991

Nursing editors back words with money.

During their Ninth Annual Meeting, international nursing editors were told of the visit of Norah Casey, editor of Nursing Standard, to Romania on behalf of the Care for Romania Appeal. She found children dying of acquired immunodeficiency syndrome, malnutrition, and other diseases. Through the Appeal nurses are being sent to care for the children and to provide education for their care givers.

Child↗