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Biomedical subjects

J Hayes

Publications and source records attributed to J Hayes.

At least 91 records · Page 5Linked to original sources
PubMed1995

Implementing accreditation systems (23 May 1994, Treviso, Italy).

Representatives of seventeen existing and developing national accreditation systems for health services met in Treviso, Italy, in May 1994. The purpose was to identify common characteristics, challenges and solutions in order to help the younger programmes to build on the experience of the well-established, particularly those in the United States, Canada and Australia. General questions and conclusions are reported with respect to aims, organisation, funding, standards development, operation and evaluation but it is emphasized that individual programmes must be designed and developed to be sensitive to local needs.

Accreditation↗
PubMed1995

A pilot study of the physician acceptance of tele-oncology.

During the winter of 1993, medical oncologists from an urban, university-based hospital provided oncology care to rural patients using interactive video clinics (tele-oncology). In order to assess physician satisfaction with this form of outreach, surveys were performed after the video encounters, as well as after a limited number of subsequent clinical encounters on site. Various aspects of satisfaction were evaluated. Although the sample was small (a total of 41 clinical encounters and 3 oncologists), the results suggested that there was a reasonable level of physician satisfaction with, and confidence in, the use of video to replace some on-site oncology consultations. A definitive study of tele-oncology for providing care to rural cancer patients therefore appears to be warranted.

Analysis of Variance↗
PubMed1994

Outcome five years after percutaneous transluminal coronary angioplasty or coronary artery bypass grafting for significant narrowing limited to the left anterior descending coronary artery.

Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are both used widely for angina but information about their comparative efficacy is limited. This study compared the outcome of 358 consecutive patients undergoing initial revascularization for significant narrowing of the left anterior descending artery (LAD) by PTCA (n = 254) or CABG (n = 104) from 1987 to 1989. PTCA was successful in 93% but complicated by urgent CABG in 3%. A left internal mammary graft was used in 88% of those having elective CABG. There was 1 perioperative death. Follow-up data were obtained after a median interval of 5.5 years (maximum 7.1). Rates for freedom from death (97% PTCA vs 93% CABG, p = 0.06) were similar, but CABG patients had greater rates for freedom from chest pain recurrence (74% CABG vs 48% PTCA, p < 0.0001), myocardial infarction (98% vs 92%, p = 0.04), and from need for further revascularization (99% vs 67%, p < 0.0001). Both groups achieved similar status, with 81% of PTCA and 90% of CABG patients having angina no worse than functional class I. Quality-of-life index was high for both groups (0.983 +/- 0.034/1.000 vs 0.987 +/- 0.032/1.000, p = 0.3). Both PTCA and CABG result in excellent survival, functional ability, and quality of life, but patients undergoing PTCA require more procedures to achieve this.

Adult↗
PubMed1994

Fabrication and characterization of low-loss, sol-gel planar waveguides.

Applications of planar integrated optical waveguide (IOW) technology to problems in surface spectroscopy and optical chemical sensing have been partly limited by the difficulty of producing high-quality glass IOWs. The fabrication of IOWs by the sol-gel method from methyltriethoxysilane and titanium tetrabutoxide precursors is described here. The physical, chemical, and optical properties of the films during and after high-temperature annealing were studied using a variety of analytical techniques. The results show that the catalyst used to accelerate the sol-gel reaction strongly influenced the optical quality of the IOW. HCl catalysis produced waveguides with propagation losses of approximately 1 dB/cm, whereas in the case of SiCl4 catalysis, propagation losses were < 0.2 dB/cm, a value significantly less than any previously reported for sol-gel-derived IOWs. An examination of film surface structure and morphology by scanning electron microscopy and atomic force microscopy showed that the SiCl4-catalyzed IOWs were significantly smoother and more homogeneous on a submicrometer scale than the HCl-catalyzed IOWs. The use of SiCl4 is thought to retard formation of a microheterogeneous network containing Si-rich and Ti-rich domains, which is favored with HCl catalysis and contributes to the higher observed losses.

Fiber Optic Technology↗
PubMed1994

Phenytoin age-dose-concentration relationship in children.

A list (n = 423) of phenytoin steady-state concentrations from children taking phenytoin alone or in combination with other drugs (n = 308) was obtained from our therapeutic drug monitoring database (1984-1990). Only 43% of concentrations were within the commonly accepted "therapeutic" or "reference" range (10-20 mg/L). Age-dose-concentration relationships showed that while occasional concentrations were above 20 mg/L, many patients receiving commonly recommended pediatric phenytoin doses (4-8 mg/kg/day) achieved concentrations below the reference range, especially children under 3 years of age. Michaelis-Menten pharmacokinetic parameters, maximal elimination rate (Vmax) and Michaelis constant (Km), were evaluated for patients with at least two steady-state concentrations measured for two or more different daily doses. Comedication with other drugs had no effect on either Vmax or Km for phenytoin. Vmax appeared to decrease significantly with age, but there was no age relationship for Km.

Adolescent↗
PubMed1994

Neutrophil collagenase in sputum from patients with cystic fibrosis.

The potential role of neutrophil elastase in causing lung damage and exacerbating the inflammatory response in cystic fibrosis (CF) has received considerable attention. Although another potent neutrophil-derived enzyme, collagenase, is implicated in tissue destruction in several interstitial lung disorders, there has been no reference to this enzyme in CF. The objective of this study was to determine whether neutrophil collagenase is present in active form in CF sputum and, if so, whether it is related to disease severity. High levels of active collagenase were detected in sputum from patients with CF, and the majority of the enzyme present was of neutrophil origin. In a group of 16 patients with CF, negative relations between sputum collagenase activity and Shwachman score (r = -0.55, p < 0.05) and FEV1 (r = -0.59, p < 0.02) were noted, indicating an association between high collagenase activity and severity of disease. A positive correlation was observed between sputum collagenase and elastase activity (r = 0.62, p < 0.05). These results suggest that both neutrophil elastase and collagenase may play a significant role in lung destruction in CF.

Adolescent↗
PubMed1994

Influence of rapid weight gain after the weigh-in on success in collegiate wrestlers.

UNLABELLED: We investigated whether acute weight gain between the weigh-in and competition was associated with success in a collegiate wrestling tournament. Wrestlers at the NCAA championships were weighed at the official weigh-in and again just before the first round of the tournament (20 h later). Weight gain and the weight discrepancy between first-round opponents were calculated (N = 607 excluding heavyweights). Indices of success included season record (% wins in total matches), tournament seeding, the sum of the advancement and placement points scored during the tournament (team points), and final placement in the tournament. ANOVA showed no differences in weight variation between placewinners and non-placewinners, or across placewinners only. Correlation coefficients among weight variables and indices of success were also low (P > 0.05). Multiple logistic regression, used to determine whether weight gain or weight discrepancy between opponents contributed to success in the first round of the tournament, revealed that neither variables was predictive of first-round outcome even after attempting to account for differences in ability (e.g., forcing team points into the regression first). CONCLUSION: neither acute weight gain after the weight-in or the weight discrepancy between opponents in the first round influenced success in a collegiate wrestling tournament.

Analysis of Variance↗
PubMed1994

Mobitz type II heart block presenting as weight loss.

Weight loss in the elderly can be due to many different disease processes, most often neoplastic. We present a case of weight loss secondary to Mobitz Type II heart block in a patient with normal left ventricular function that was reversed with a permanent pacemaker implantation. Weight loss in the elderly is a common manifestation of many disease processes. We present an unusual case of weight loss, malaise and dyspepsia that was completely reversed by pacemaker implantation for Mobitz Type II heart block.

Aged↗
PubMed1993

Mechanisms of action of long-acting analogs of somatostatin.

The prolactin secreting rat pituitary tumor cell line, GH3, expresses high affinity receptors for both vasoactive intestinal peptide (VIP) and somatostatin (SS14). VIP induces prolactin secretion by GH3 cells, an action which is antagonized by SS14. This in vitro model was used to examine the mechanism of action of two synthetic somatostatin analogs, D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OH (octreotide; SMS 201-995) and cyclo(aminoheptanoyl-Phe-D-Trp-Lys-Thr (benzyl)) (cyclic pentapeptide; CPP). Octreotide and CPP bind to the pituitary somatostatin receptor with lower affinity than does SS14 (KD = 1.3 +/- 1.1; 80 +/- 29; 211 +/- 107 nM for SS14, octreotide and CPP, respectively). SS14 and octreotide were equally effective as inhibitors of VIP-mediated accumulation of cAMP (40% and 45% inhibition, respectively, P < 0.01). SS14 and octreotide also inhibited forskolin-mediated accumulation of cAMP (42% and 40% inhibition of cAMP production, respectively; P < 0.01). The inhibitory action of somatostatin and octreotide on both VIP- and forskolin-mediated cAMP accumulation was blocked by pre-treatment of GH3 cells with pertussis toxin (P < 0.001). Neither SS14 nor octreotide affects the apparent affinity of VIP for its specific receptors on GH3 cells; thus, the inhibitory action of SS14 and octreotide appears to be mediated at the locus of the G-protein-adenylate cyclase complex. In contrast, CPP inhibited VIP-mediated cAMP accumulation slightly, but had no effect on forskolin-mediated cAMP production. Pertussis toxin did not attenuate CPP affects on VIP-mediated cAMP accumulation. However, pre-incubation of GH3 cells with CPP decreased the apparent affinity of receptors for VIP, suggesting that effects of CPP are attributable to interference with VIP binding rather than inhibition at the G-protein-adenylate cyclase complex.

Amino Acid Sequence↗
PubMed1993

Airway allergy to trimellitic anhydride in guinea pigs: different time courses of IgG1 titer and airway responses to allergen challenge.

BACKGROUND: Trimellitic anhydride (TMA) is a low molecular weight chemical that may cause occupational asthma in human beings. The objectives of this study were to determine the time course of immune and airway responses to TMA in guinea pigs and to relate the immunologic response to the immediate responses in lung resistance (RL) and plasma exudation induced by allergen challenge. METHODS: We studied the effects of time course after sensitization on airway response to TMA in guinea pigs actively sensitized to free TMA, given by intradermal injection (0.1 ml of 0.3% TMA in corn oil). During weeks 1, 2, 3, 5, and 8 after sensitization, anesthetized animals were challenged with TMA conjugated to guinea pig serum albumin (TMA-GPSA), instilled via the airway route. Nonsensitized animals were challenged with the same amount of conjugate 4 weeks after intradermal injection of corn oil only. In the same animal, we measured both RL to monitor airflow obstruction and extravasation of Evans blue dye (20 mg/kg) to quantify airway plasma exudation. RESULTS: Instillation of TMA-GPSA (0.5%; 50 microliters) into the tracheal lumen caused a significant increase in RL, reaching a maximum at 2.5 minutes after the instillation in the 1-week group (9.0 +/- 5.9 cm H2O/ml/sec) and between 5 and 6 minutes in the 2-, 3-, 5-, and 8-week groups (9.4 +/- 4.8, 12.7 +/- 5.5, 3.7 +/- 1.1, and 1.7 +/- 0.2 cm H2O/ml/sec, respectively). The maximal increase in RL after the challenge in nonsensitized animals was 0.39 +/- 0.05 cm H2O/ml/sec. TMA-GPSA also produced significant extravasation of Evans blue dye at all airway levels in the sensitized groups, and the amount of dye in the peripheral airways was significantly greater than that in the trachea. Furthermore, the level of Evans blue dye in airway tissue increased with the time after sensitization, up to the latest time point tested (8 weeks). Specific IgG1 antibodies to TMA-GPSA demonstrated by ELISA were detected in all animals in the 3-, 5-, and 8-week groups, with maximal levels 5 weeks after sensitization. Specific IgG1 titers to TMA-GPSA significantly correlated with the level of Evans blue dye induced by challenge with TMA-GPSA but not with the increase in RL. CONCLUSIONS: Intradermal sensitization to free TMA induces specific airway allergy for a long period after sensitization. Specific IgG1 antibodies to allergen may influence allergen-induced plasma exudation rather than the airflow obstruction in this animal model of TMA-induced asthma.

Animals↗
PubMed1993

Role of arachidonic acid metabolites in airway responses induced by trimellitic anhydride in actively sensitized guinea pigs.

We studied the role of arachidonic acid metabolites, histamine, and 5-HT in airway responses to trimellitic anhydride (TMA) in actively sensitized guinea pigs. Sensitization was produced by two intradermal injections of free TMA (0.1 ml of 0.3% TMA in corn oil). After 21 to 28 days, guinea pigs were anesthetized and challenged with intratracheal instillation of 0.5% TMA conjugated to guinea pig serum albumin (TMA-GPSA; 50 microliters). Lung resistance (RL) was measured to assess airflow obstruction, and the tissue content of Evans blue dye was measured to assess airway plasma exudation. Before challenge, sensitized animals were pretreated intravenously with inhibitors of different mediators: pyrilamine (antihistamine: 2 mg/kg, indomethacin (cyclooxygenase inhibitor: 10 mg/kg), OKY-046 (thromboxane synthetase inhibitor: 30 mg/kg), ICI-198,615 (leukotriene receptor antagonist: 10(-6) mol/kg), ketanserin (5-HT2 receptor antagonist: 1 mg/kg), or azelastine ("antiallergic agent": 1 mg/kg). Intratracheal instillation of TMA-GPSA induced a slowly progressing increase in RL and produced extravasation of Evans blue dye at all airway levels in sensitized animals. Pyrilamine and azelastine abolished the increase in RL induced by TMA-GPSA until 2.5 min after the challenge. Indomethacin and OKY-046 significantly attenuated the increase in RL 3 min after the challenge. ICI-198,615 and ketanserin did not significantly affect the increase in RL. Extravasation of Evans blue dye induced by TMA-GPSA was decreased by pyrilamine, azelastine and ICI-198,615 in main bronchi and intrapulmonary airways. Indomethacin, OKY-046 and ketanserin did not significantly affect the extravasation of dye into the airway tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1993

Reliability determination of F mean response latency.

Two hundred consecutive ulnar F wave latencies were evaluated in 30 healthy controls (C) and in 9 patients with mild neuropathy (N). The primary study objective was to determine the F wave sample size required to obtain a reliable F mean latency. A secondary objective was to explore the diagnostic utility of three F wave parameters: the minimal F wave latency (Fmin), the average F wave latency (Fmean), and the minimal-maximal F wave latency difference (Frange). For the control group, the Fmean reliability estimates as measured by intraclass correlation coefficients were 0.87, 0.97, and 0.99 with 1, 5, and 10 responses, respectively; for the N group, the corresponding values were 0.73, 0.93, and 0.96. Fmean was abnormal in 89% of the subjects with mild neuropathy whereas Frange and Fmin were abnormal in 67% and 33%, respectively. The study suggests (1) a reliable F mean latency can be obtained by averaging ten F responses; and (2) Fmean and Frange offers promise in increasing the diagnostic utility of the F response in identifying mild neuropathies.

Adult↗
PubMed1992

Compliance with breast self-examination instruction in high school students.

In a prospective study, we measured compliance with breast self-examination, using an anonymous questionnaire, in suburban high school students three months (n = 85) and eight months (n = 54) after group instruction. Post-instruction proficiency in performing the procedure and personal health beliefs regarding breast cancer were also evaluated. At three months, 40% of the group reported practicing breast self-examination at some time since instruction; 12% had performed the procedure timed correctly with their menstrual cycle. At eight months, only two girls (4%) had practiced breast self-examination at least once since the three-month evaluation. Proficiency scores overall were high, with 77% scoring 12 points or above on a 15-item questionnaire; however, scores were significantly lower in the 15-year-olds than in the older adolescents. No significant relationships were found between compliance and most personal health beliefs, previous instruction, or level of knowledge of the procedure. Attention should be directed toward assessing the ability and willingness to practice preventive health behaviors before instruction programs are instituted in this age group.

Adolescent↗