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Biomedical subjects

A Allen

Publications and source records attributed to A Allen.

At least 19 recordsLinked to original sources
PubMed1992

Malignant myositis ossificans. A case report.

A patient presented with an ossifying thigh mass suggestive of myositis ossificans. He had no antecedent trauma to the area. The mass was found to be an ossifying soft tissue metastasis from an occult gastric adenocarcinoma primary. Malignancy, and especially metastatic malignancy, is rarely considered in the differential diagnosis of a radiographic presentation of myositis ossificans.

Adenocarcinoma, Mucinous↗
PubMed1992

Phase II evaluation of piroxantrone in renal cell carcinoma. A Southwest Oncology Group Study.

The Southwest Oncology Group (SWOG) studied the response rate and toxicity of piroxantrone (150 mg/m2 q 21 days) in patients with advanced metastatic renal cell carcinoma. Among 32 eligible patients, there were no partial nor complete responses. There were two mixed responses. Significant white cell toxicity, anemia, nausea, and vomiting were observed. Mild or moderate degrees of fever, malaise, and stomatitis occurred. No significant cardiac toxicity was noted. Piroxantrone does not have significant activity as a single agent in advanced renal cell carcinoma.

Adult↗
PubMed1992

Retrospective search for bleeding diathesis among premature newborn infants with pulmonary hemorrhage after synthetic surfactant treatment. The American Exosurf Neonatal Study Group I, and the Canadian Exosurf Neonatal Study Group.

In an across study analysis of five multicenter, placebo-controlled trials of the synthetic surfactant, Exosurf Neonatal, involving infants with birth weights 700 gm or greater the incidence of clinical pulmonary hemorrhage was 1.9% in treated infants and 1.0% in control infants. To determine whether this apparent increase in pulmonary hemorrhage was the result of a bleeding diathesis, we retrospectively reviewed charts for 39 of 41 infants with clinical pulmonary hemorrhage. The incidence of nonpulmonary bleeding was the same in control- and surfactant-treated infants. Platelet counts, hematocrit values, and the number of transfusions with platelets or red blood cells did not differ between the two groups. There was no evidence that surfactant treatment was specifically associated with a generalized bleeding diathesis.

Double-Blind Method↗
PubMed1992

The relationship between paroxetine and the sparteine oxidation polymorphism.

The relationship between the selective serotonin reuptake inhibitor paroxetine and the sparteine oxidation polymorphism was investigated in a combined single-dose (30 mg) and steady-state (30 mg/day for 2 weeks) study including a panel of nine extensive metabolizers and eight poor metabolizers of sparteine. The median area under the plasma concentration-time curve (AUC) after the first paroxetine dose was about seven times higher in poor metabolizers than in extensive metabolizers (3910 versus 550 nmol.hr/L), whereas at steady state the median AUCss tau interphenotype difference was only twofold (4410 versus 2550 nmol.hr/L). Plasma half-life and steady-state plasma concentration were significantly longer and higher, respectively, in poor metabolizers than in extensive metabolizers (41 versus 16 hours and 151 versus 81 nmol/L). Paroxetine pharmacokinetics were linear in poor metabolizers and nonlinear only in extensive metabolizers. Sparteine metabolic ratio (MR = 12 hour urinary ratio of sparteine/dehydrosparteine), increased during treatment with paroxetine in subjects who were extensive metabolizers, and after 14 days treatment two extensive metabolizers were phenotyped as poor metabolizers and the remaining extensive metabolizers were changed into extremely slow extensive metabolizers with sparteine MRs of 5.7 to 16.5. The inhibition of sparteine metabolism was rapidly reversed after cessation of paroxetine administration. In the poor metabolizers there were no significant changes in MRs during the study. It is concluded that paroxetine and sparteine metabolism cosegregates, but the interphenotype difference in metabolism was less prominent at steady state than after a single dose, presumably because of saturation of the sparteine oxygenase (CYP2D6) in subjects who were extensive metabolizers. Paroxetine is a potent inhibitor of sparteine oxidation by CYP2D6 in vivo.

Adult↗
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↗