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Biomedical subjects

J A Hayes

Publications and source records attributed to J A Hayes.

At least 37 records · Page 2Linked to original sources
PubMed1995

Forced expiratory flow is reduced by 100% oxygen in patients with chronic obstructive pulmonary disease.

In order to determine the effect of breathing high fractional concentrations of oxygen on forced expiratory flow in individuals with chronic obstructive pulmonary disease (COPD), we studied 18 patients with moderately severe disease. The patients were studied breathing air, 100% oxygen, or a four-gas mixture in a randomized double-blind study design. The four-gas mixture (oxygen 21.0%, argon 48.6%, nitrogen 19.3%, and helium 11.1%) was calculated to have a density and viscosity similar to oxygen. During spirometric testing, breathing oxygen produced a detectable reduction in timed volumes by 1 minute that was sustained at 5 minutes (FEV1 reduction 4.9% at 1 minute and 6.3% at 5 minutes). Breathing the gas mixture for 5 minutes resulted in similar reductions in flow. We conclude that high concentrations of oxygen reduce forced expiratory flow in patients with airflow obstruction, an effect probably related to the increased density and viscosity relative to air. This reduction in forced expiratory flow may contribute to the deterioration seen when COPD patients with acute respiratory failure are treated with 100% oxygen.

Aged↗
PubMed1994

Evaluating the quality of articles published in journal supplements compared with the quality of those published in the parent journal.

OBJECTIVES: To determine the relationship between the quality of articles and whether they were published in a supplement or in the parent journal. DATA SOURCES AND STUDY SELECTION: All randomized control trials of drug therapies in adults published in the American Journal of Cardiology, the American Journal of Medicine and the American Heart Journal from January 1990 and obtained in November 1992 by means of a MEDLINE search. A total of 318 abstracts appeared to meet our inclusion criteria, and these articles were obtained and reviewed in further detail. An additional 76 were excluded. DATA EXTRACTION: Three reviewers who were "blinded" and thus unaware of supplement status independently assessed the quality of each of the remaining 242 articles according to a standard quality scoring system. DATA SYNTHESIS: Overall, 67 (27.7%) of the articles were published in journal supplements. Article quality scores ranged from 4.2% to 87.5%, with a mean (+/- SD) score of 37.2% +/- 13.1%. Quality scores were lower in articles published in journal supplements than in those published in the parent journal (t[240] = 2.61, P = .01). The mean quality score for articles published in journal supplements was 33.6% +/- 12.8% compared with a score of 38.5% +/- 13.1% for articles published in the parent journal. Supplement articles included in their final analysis a smaller proportion of the patients initially randomized (t[75] = 2.8, P = .007). CONCLUSION: Our findings suggest that randomized control trials published in journal supplements are generally of inferior quality compared with articles published in the parent journal. The review process surrounding the publication of journal supplements should be consistent with that of the parent journal.

Peer Review, Research↗
PubMed1993

Isolation and identification of a novel peptide from the accessory sex gland of the female house fly, Musca domestica.

A peptide of novel structure was isolated from accessory glands of the female house fly, Musca domestica by molecular-weight limit centrifugal ultrafiltration and reversed-phase HPLC. After amino acid and protein sequence analyses, the structure of this peptide was confirmed by chemical synthesis and plasma desorption mass spectral analysis to be Leu-Leu-Asn-Ala-Leu-Pro-Leu-Asp-Ala-Leu-Ser-Ser-Leu-Thr-Gly-NH2. The accessory gland peptide stimulated contraction of the house fly oviduct at concentrations of 10(-7) M and above.

Amino Acid Sequence↗
PubMed1993

The effect of forceps size on the adequacy of specimens obtained by transbronchial biopsy.

This study prospectively compared the diagnostic yield of transbronchial biopsies using large and small forceps (cup sizes, 3 x 2 x 0.9 versus 2 x 1.5 x 0.6 mm, respectively). Diagnostic yield was compared by a pathologist, blinded to the size of forceps used on the basis of the relative amount of tissue obtained, alveolar tissue obtained, and ability to ascertain a histopathologic diagnosis. Large forceps obtained significantly more tissue than did small forceps (20 of 27 patients [74%] versus five of 27 patients [19%], p < 0.005, with similar amounts obtained in two patients). Also, large forceps obtained significantly more alveolar tissue than did small forceps (16 of 22 patients [73%] versus six of 22 patients [27%], p < 0.05, with no alveolar tissue obtained in five patients). In 18 of the 27 patients, biopsies performed resulted in nonspecific diagnoses, including fibrosis or chronic inflammation. All nine of the patients with a specific diagnosis were ultimately proved to have sarcoidosis. There was a trend toward more of these patients having noncaseating granulomas obtained with the large forceps than with the small forceps (seven of nine patients versus four of nine patients). No difference was observed in the amount of postbiopsy bleeding with either forceps. We conclude that large forceps used for transbronchial biopsy yield more tissue and more alveolar tissue than do small forceps. These findings may have an impact on the diagnostic yield in some diseases such as sarcoidosis.

Adult↗
PubMed1992

An extended phase II trial of ifosfamide plus mesna in malignant mesothelioma.

Forty three patients with histologically confirmed malignant mesothelioma were entered onto an Eastern Cooperative Oncology Group phase II study of ifosfamide given with mesna. Eligibility criteria included adequate performance status, hemogram and renal functions. Ifosfamide was given at 1.5 g/m2 in 200 ml of normal saline over 30 minutes by intravenous infusion on days 1 to 5 of each 21 day cycle. Mesna was given at 300 mg/m2 on each day of ifosfamide at 0, 4 and 8 hours. Two patients were cancelled and one patient was ineligible. The most common toxicity was haematologic. More than 50% of the patients had at least one episode of severe or life threatening toxicity and 2 patients had lethal toxicity (1 renal and 1 pulmonary oedema attributed to treatment), and an additional 4 patients died while on study (2 of cardiac and 2 of cerebral vascular disease not considered directly related to treatment). Of the 40 eligible patients one was unevaluable for response, and one patient had a partial response lasting 6.3 months. Twenty four patients had a no change status with a median duration of 5 months. The median time to treatment failure for all eligible patients was 2.5 months. The median overall survival time (from registration) for all eligible patients was 6.9 months. In multi variable models, factors that predicted for a statistically significant poorer survival were age > or = 62, stage > or = 3, performance status poorer than 0 to 1 and prior surgery (i.e.: more than biopsy).(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Administration Schedule↗
PubMed1992

Health care as a natural right.

Health care is recognized as a right in the Universal Declaration of Human Rights and by the World Health Organization's Declaration on the Rights of Patients. This article demonstrates that this concept of a 'right' to health care draws strong support from leading modern works on natural law and justice and responds to the arguments, both theoretical and practical, put forward against this proposition. It concludes with two warnings: (a) Even in a system where health care is said to be a right, this can be meaningless if the system does not promote basic health, fails to set proper legal and ethical controls or ignores the important individual rights of patients. (b) Our primary commitment must be to those persons who are denied access to health care. To them, talk of patient's individual rights is superfluous. They cannot claim such rights if they are denied the more fundamental right to be a patient.

Ethics↗
PubMed1991

Effects of therapist-trainees' anxiety and empathy on countertransference behavior.

This study examined the relationship between therapist-trainees' state anxiety and countertransference behavior and the possible moderating role played by empathy. Primary hypotheses were: (a) Trainee state anxiety is related positively to countertransference behavior; and (b) the adverse effects of anxiety would influence only less empathic trainees. Thirty-five trainees (11 males, 24 females) conducted counseling sessions with each of two clients, who then rated their counselor's empathy. Countertransference behavior subsequently was assessed through trainees' responses to two audiotaped clients; state anxiety was self-reported after each audiotape "session." State anxiety was found to relate to countertransference as predicted, but only for male trainees. The hypothesized moderating effect of empathy was unsupported. The role of gender as related to anxiety and countertransference is discussed.

Adult↗
PubMed1991

Managing countertransference: what the experts think.

The present study attempted to assess the importance of five factors theorized to play a central role in managing countertransference: Self-integration, Anxiety Management, Conceptualizing Skills, Empathy, and Self-insight. 33 experts provided ratings of 50 characteristics of therapists as to the importance of each in managing countertransference. Analysis indicated that each factor is at least somewhat important to management of countertransference, with two of the factors, Self-integration and Self-insight, rated as playing a particularly important role. Clinical implications are discussed.

Adaptation, Psychological↗
PubMed1990

Hedging opportunities in health care.

Medical care futures contracts offer new hedging opportunities to increase protection against unexpected price changes. Commodity futures contracts can be designed explicitly to hedge volatile group health insurance premiums and capitated hospital and physician prices. This article describes one way to design and use these hedging instruments.

Accounting↗
PubMed1987

Tumor regression and temporary restoration of immune response after plasmapheresis in a patient with recurrent oral cancer.

A major response to plasmapheresis is reported in a patient with advanced, recurrent squamous cell cancer of the oral cavity, similar to that previously reported in three of six comparable patients. Tumor regression followed temporary reduction of inhibition of normal lymphocyte response to phytohemagglutinin (PHA) by the patient's serum (from 99% to zero) and partial restoration of the patient's lymphocyte response (from 2% to 38% of control). The IgE level rose both overall and during some exchanges; this correlate of tumor response had been noted earlier. The tumor showed extensive necrosis, but the clinical effects were relatively short-lived and the patient died 11 weeks later. Biopsy specimens taken early in apheresis showed intense new infiltration of tumor by lymphocytes and monocytes; later biopsy specimens showed predominantly plasma cells with trapping and lysis of tumor cells. No other anti-cancer therapies had been used for 16 months before this trial, and no replacements were given other than saline and albumin.

Antigens, Surface↗
PubMed1987

Neointimal hyperplasia occurring after carotid endarterectomy in a canine model: effect of endothelial cell seeding vs. perioperative aspirin.

Neointimal hyperplasia of the arterial wall may occur after carotid endarterectomy. This proliferative lesion is a pathologic response of the injured arterial wall and may lead to progressive stenosis. We investigated the effect of endothelial cell seeding (ECS) or antiplatelet therapy with aspirin (ASA) on inhibition of this lesion in a canine model. Endarterectomies were performed in 160 carotid arteries; 46 endarterectomies were treated perioperatively with aspirin (325 mg per day), 34 were seeded with a high density (3 X 10(6)) of autogenous endothelial cells, and 80 were untreated control arteries. At selected time intervals, the patent arteries were perfusion-fixed and the cross-sectional area (measured in square millimeters) of neointimal hyperplasia was measured by means of digital planimetry. At 6 weeks, patency of the endarterectomized carotid artery was 88% in the ASA and ECS groups, in contrast to 35% in the control group (p less than 0.01). The cross-sectional area of neointimal hyperplasia was not significantly different in the ASA and the control groups at 6 weeks. However, the ECS group showed a marked reduction in neointimal hyperplasia at 6 weeks (p less than 0.01). This inhibition of neointimal hyperplasia after carotid endarterectomy by ECS may reflect accelerated luminal healing or a direct inhibition of smooth muscle cell proliferation in the injured arterial wall.

Animals↗
PubMed1985

Delayed fatal pulmonary hemorrhage complicating use of a balloon flotation catheter.

A case of delayed fatal pulmonary hemorrhage caused by a balloon flotation catheter is described. The catheter was inserted preoperatively. The patient died on the 14th postoperative day from massive hemorrhage in the right pleural space after 12 days without any clinical symptoms. Pulmonary artery rupture is documented by the autopsy findings.

Aged↗
PubMed1984

Alterations in collagen biosynthesis and in metallothionein in lungs of rats acutely or repeatedly exposed to cadmium chloride aerosol.

Comparisons were made between morphologic and biochemical changes occurring in the lungs of rats receiving a single exposure or repeated 2-h exposures of aerosolized 0.1% cadmium chloride, simulating varied exposure conditions potentially experienced by humans. Lung lysyl oxidase activity increases in both models, although less so with repeated exposures. Pulsing lung tissue in vitro with 3H-proline indicated that rates of collagen biosynthesis were elevated preferentially over rates of noncollagen protein synthesis in both exposure models. Lung metallothionein increased nearly linearly over 21 days of repeated exposure. Histologic examination revealed scarred lesions distorting alveolar structure and bronchioles in both models. However, scarring and cell exudation into the airways and interstitium was less in the repeatedly exposed model. The results indicate the activation of a connective tissue repair reaction in both models. Increased levels of metallothionein after repeated exposure may both sequester cadmium and reduce pools of copper available for lysyl oxidase synthesis, thus limiting the fibrotic response.

Aerosols↗
PubMed1984

Wound healing following mastectomy.

Local complications following mastectomy are of considerable importance if peri-operative chemotherapy is to be used. A retrospective survey of 100 patients following Patey mastectomy was therefore undertaken to investigate problems associated with wound healing in the absence of such therapy. The survey showed that 18% of patients developed postoperative wound infection, this being severe in 50% of cases. Varying degrees of total wound breakdown occurred in 9% of patients while delayed healing occurred in a further 5%. The incidence of seroma was 25%, and the majority of these patients required further drainage. There was a significant association between seroma formation and wound infection (P less than 0.05). The mean length of hospital stay in patients without wound infection was 11.7 days, but was increased to 27.3 days when infection occurred (P less than 0.001).

Female↗
PubMed1984

Fat embolism in sickle cell disease. Report of a case with brief review of the literature.

This is a unique instance of fatal fat embolism secondary to bone marrow necrosis in a patient with sickle cell-hemoglobin C disease, systemic lupus erythematosus, and Sjögren's syndrome. An elevated level of IgG and treatment with corticosteroids appeared to be major factors in the death of this patient. This complication occurs most often in patients with sickle cell-hemoglobin C disease, especially in pregnant women near term. It should be suspected in any patient with sickle cell disease in whom unexplained fever, respiratory, and neurologic symptoms typical of fat emboli develop following the onset of bone pain. Exchange blood transfusion may be lifesaving.

Adult↗
PubMed1983

Lung aryl hydrocarbon hydroxylase: inhibition following cadmium chloride inhalation.

Polycyclic hydrocarbon metabolism in male Sprague-Dawley rats following inhalation of aerosolized cadmium chloride (CdCl2) was examined. Constitutive activity of microsomal aryl hydrocarbon hydroxylase (AHH) (benzo(a)pyrene substrate) was monitored in lung and liver homogenates up to 10 days after exposure. Lung AHH activity was reduced by 85% during the first 2 days following cadmium inhalation, and did not return to normal levels until 7 days after exposure. Enzyme activity in the livers of cadmium-treated animals was similarly depressed (by 65%) within 24 hr. Cadmium inhalation also inhibited (by 50%) 3-methylcholanthrene (MC) induction of lung AHH when compared with MC-treated controls. No significant effect on AHH inducibility by MC was noted in liver homogenates from cadmium-exposed animals. Nonspecific microsomal damage appeared not to occur since glucose-6-phosphatase activity in lung was unaffected by cadmium treatment. Although the mechanism of cadmium's action remains unclear, it appears not to involve a direct interaction of the metal with enzyme. The alteration of AHH activity by cadmium may result from injury to a specific cell type within the lung, which may be a major site of pulmonary AHH activity, or may result from modulation of synthesis and/or degradation of heme proteins in the lung. These results suggest that cadmium, under these conditions, markedly reduces the constitutive and inducible activity of AHH in the lung.

Aerosols↗