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Biomedical subjects

R Morris

Publications and source records attributed to R Morris.

At least 217 records · Page 12Linked to original sources
PubMed1994

Measuring blood pressure in pregnant women: a comparison of direct and indirect methods.

OBJECTIVES: Our goals were to determine (1) whether Korotkoff phase IV or V sound was a more accurate measure of diastolic blood pressure in pregnancy and (2) interobserver variability of mercury sphygmomanometry of pregnant women. STUDY DESIGN: Direct (intraarterial) and indirect (mercury sphygmomanometry) blood pressures were compared in 28 pregnant women. Interobserver variability was assessed in a separate study of 86 pregnant women using four highly trained observers. RESULTS: (1) Routine sphygmomanometry underestimated direct systolic pressure by 11 (3, 18) mm Hg, p < 0.001 (median, interquartile range of differences). Phase IV Korotkoff sound overestimated direct diastolic pressure by 9 (2, 12) mm Hg (p < 0.001) and phase V by 4 (2, 7) mm Hg (p = 0.04). Phase V-recorded diastolic pressure was closer to direct diastolic pressure significantly more often (75%) than was phase IV-recorded diastolic pressure (21%) (p = 0.003). Mean arterial pressures did not differ significantly according to the method used. (2) Median blood pressures did not differ among the four observers for systolic, diastolic phase IV, or phase V recordings. Maximum difference for blood pressure recording among observers was 4 (2, 6) mm Hg. CONCLUSIONS: Auscultatory sphygmomanometry in pregnant women underestimates systolic and overestimates diastolic blood pressure, but the phase V Korotkoff sound is more likely to represent the true diastolic pressure than is the phase IV sound.

Auscultation↗
PubMed1994

Comparison of biphasic and monophasic waveforms in epicardial atrial defibrillation.

OBJECTIVES: Because biphasic waveforms have previously been shown to be more efficient than monophasic waveforms in defibrillation of the ventricle, we compared the efficiency of the two waveforms in defibrillation of the atria. BACKGROUND: The development of an implantable atrial defibrillator would offer significant advantages over current approaches to the management of atrial fibrillation. Patient tolerance of atrial shocks from such a device, however, would depend critically on the deployment of an efficient waveform. METHODS: Both the monophasic and biphasic shocks were of 8-ms duration, and the biphasic was a dual-capacitor waveform with equal first- and second-phase duration and leading-edge voltage. One hundred randomized atrial shocks were evaluated in 21 patients during cardiopulmonary bypass. Atrial fibrillation was induced by the application of alternating current. Atrial shocks were delivered through customized, contoured epicardial paddles applied to the posterior left atrial wall (surface area 11 cm2) and to the anterior right atrial wall (surface area 26 cm2). RESULTS: For the monophasic waveform the delivered energy (joules) associated with 50% success (E50) was 1.44 J (95% confidence interval [CI] 0 to 11.2) and with 80% (E80) success 3.9 J (95% CI 2.42 to 109.8); for the biphasic waveform 50% success was achieved with 0.37 J (95% CI 0.36 to 0.38) (p = NS) and 80% success with 0.57 J (95% CI 0.56 to 0.58) (p < 0.05). CONCLUSIONS: A biphasic waveform is more efficient than a monophasic waveform in atrial defibrillation. This may have implications for the development of an implantable atrial defibrillator for paroxysmal atrial fibrillation in addition to improvement of elective transthoracic and endocardial cardioversion of chronic atrial fibrillation.

Aged↗
PubMed1994

Sexual communication is associated with condom use by sexually active incarcerated adolescents.

PURPOSE: Incarcerated adolescents are at increased risk for infection by sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV). Moreover, condom use by this population is extremely low. Although interpersonal variables such as sexual communication have been found to be associated with condom use in other populations, few researchers have investigated this relationship among adolescents requiring detention in juvenile facilities. The present study investigated the relationship between communication about sexual history and incarcerated adolescents' condom use. METHODS: We used multivariate logistic regression techniques to analyze interview data from a predominantly Latino sample of 2,132 sexually active adolescents detained in Los Angeles County Juvenile Hall. RESULTS: Despite high numbers of lifetime sexual partners, a substantial majority of respondents (67%) reported that they never used condoms during sexual intercourse. Respondents who communicated with their sex partner(s) about each others' sexual history were significantly more likely to use condoms during sexual intercourse. Adolescents who reported that they knew someone with AIDS were also more likely to use condoms. CONCLUSIONS: Interventions designed to increase condom use among sexually active incarcerated adolescents should include a component addressing sexual communication practices. More research is needed on the ways in which adolescents learn to communicate about sex.

Adolescent↗
PubMed1994

Hepatitis B markers in Gloucestershire firemen.

Occupational exposure to blood and body fluids and the prevalence of serological markers of hepatitis B virus (HBV) infection were studied in Gloucestershire firemen to assess the occupational risk of HBV infection. A high compliance was achieved (472/503, 94 per cent). Cumulative occupational exposure to blood or body fluids rose progressively to 68 per cent after 24 years' service. No sera were positive for hepatitis B surface antigen (HBsAg). Six sera were positive for hepatitis B surface antibody (anti-HBs) and were tested for hepatitis B core antibody (anti-HBc). The four subjects who were positive for anti-HBs alone had all received HBV vaccine. Two sera contained both anti-HBs and anti-HBc. Therefore, 2/472 firemen (0.42 per cent) showed evidence of previous HBV infection, a similar proportion to that found in a recent study in UK blood donors (0.49 per cent). Despite considerable exposure to blood and body fluids, an occupational risk of hepatitis B infection was not found in Gloucestershire firemen.

Adult↗
PubMed1994

Sex steroid biosynthesis enzymes in ovarian sex-cord stromal tumors.

Previous studies on neoplastic and hyperplastic ovarian lesions using paraffin-embedded material have demonstrated immunolocalization of sex steroid biosynthetic enzymes (SSBEs): P-450 side chain cleavage (P-450 SCC), which converts cholesterol to pregnenolone; 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), which converts pregnenolone to progesterone; P-450 17 alpha-hydroxylase and lyase (P-450 17A), which convert progesterone to 17 alpha-hydroxyprogesterone and 4-androstene-3,17-dione; and P-450 aromatase (P-450 AR), which converts 4-androstene-3,17-dione to estradiol. To investigate the utility of immunohistochemical staining for SSBEs, we studied a series of 45 sex cord-stromal tumors of the ovary. P-450 SCC was present in 9 of 11 Sertoli-stromal cell tumors, 3 of 12 granulosa cell tumors, 2 of 7 thecomas, and 1 of 1 stromal luteomas; 3 beta-HSD was present in 5 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, 2 of 7 thecomas, and 1 of 1 stromal luteoma; P-450 17A was present in 5 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, 2 of 6 thecomas, and 1 of 1 stromal luteomas; P-450 AR was present in 6 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, none of 7 thecomas, and 1 of 1 stromal luteoma. SSBEs were not present in 12 fibromas, one sclerosing stromal tumor, and one myxoma. Five of 45 patients with sex cord-stromal tumors showed androgenic effects; 4 of 11 patients with Sertoli-stromal cell tumors and the patient with a stromal luteoma. These five sex cord-stromal tumors contained P-450 SCC, and three of four of the Sertoli-stromal cell tumors contained 3 beta-HSD, P-450 17A, and P-450 AR. Concurrent endometrial histology was available in 25 of 45 sex cord-stromal tumor patients. None of the five sex cord-stromal tumors arising in patients with endometria that showed hyperplasia or adenocarcinoma showed immunoreactivity for SSBEs. Eight patients' endometria were unremarkable, but their sex cord-stromal tumor contained SSBEs. SSBEs were present in areas showing Leydig cell, Sertoli cell, or steroid cell differentiation or luteinized areas; however, the results did not significantly add to the histologic classification of sex-cord stromal tumors. Androgenic hormonal effects could always be explained by synthesis of hormones by SSBEs present in the patient's sex cord-stromal tumor.(ABSTRACT TRUNCATED AT 400 WORDS)

3-Hydroxysteroid Dehydrogenases↗
PubMed1994

Hazardous chemicals: psychological dimensions of the health sequelae of a community exposure in Texas.

STUDY OBJECTIVE: A chemical spill from an oil refinery exposed the local community to more than 40,000 lb of highly toxic and corrosive hydrofluoric acid. A community based symptom prevalence study found an association between exposure and physical symptoms: the psychological impact of the disaster and its potential effect on the reporting of physical symptoms is examined here. DESIGN: The study used a population based survey design consisting of two phases: phase I, the exposure phase, and, phase II, the symptom prevalence phase. SUBJECTS: In phase I, information indicative of exposure was collected on 10,811 individuals in a door to door survey of a geographically defined area. In phase II, symptom prevalence information was gathered through in-person interviews with 2509 subjects selected from the phase I census in a sampling scheme that balanced across the exposure categories with regard to age, gender, and predisposition. The refusal rate in both phases was < 5%. MEASUREMENT AND MAIN RESULTS: Stepwise logistic regression analyses were used to assess the relative predictive importance of psychological variables and hydrofluoric acid exposure in explaining the reported physical symptoms two years after the disaster. The findings show a linear relationship between the level of hydrofluoric acid exposure and the degree of psychological stress two years after the accident. High exposure had a long term (more than two years) impact on physical health for some self reported symptoms, even after controlling for the psychological impact. Some physical symptom reports, however, were better explained by psychological status than by exposure to hydrofluoric acid. The physical symptoms for which exposure was the major predictor were those for which the biological plausibility of a relationship with hydrofluoric acid exposure was direct. CONCLUSIONS: Measures of psychological status should be included in symptom studies of health sequelae to man-made disasters so that the physical effects of exposure can be more accurately assessed.

Adolescent↗
PubMed1994

The correlation between the distribution of the NK1 receptor and the actions of tachykinin agonists in the dorsal horn of the rat indicates that substance P does not have a functional role on substantia gelatinosa (lamina II) neurons.

The presence of substance P in primary afferents that terminate in the outer laminae of the spinal cord has led to considerable interest in the function of this neuropeptide in nociception. We have examined the actions of tachykinin agonists on the membrane potential of neurons in lamina II of a neonatal spinal cord slice preparation in vitro. Only 10.5% (n = 75) of these neurons showed any response to the application of a selective NK1 receptor agonist while 48.3% (n = 60) of neurons in deeper dorsal horn laminae responded to this agonist. Lamina II neurons were equally insensitive to selective NK2 and NK3 agonists. Synaptic potentials evoked in lamina II neurons by peripheral nerve stimulation were similarly not altered by the NK1 agonist. Immunocytochemical studies using an antibody raised against the C-terminal of the NK1 receptor revealed that very few lamina II neurons express NK1 receptors, and this offers an explanation for our findings.

Afferent Pathways↗
PubMed1993

Demonstration of two isoforms of the SERCA-2b type Ca2+,Mg(2+)-ATPase in pancreatic endoplasmic reticulum.

An antibody raised against a 12 amino acid peptide corresponding to the C-terminal sequence of the SERCA-2b Ca2+,Mg(2+)-ATPase precipitated Ca2+,Mg(2+)-ATPase activity from pancreatic rough ER. Thapsigargin and vanadate inhibited the activity with the same concentration-dependence as for native ER membranes. Partial purification of Ca2+,Mg(2+)-ATPase using Reactive Dye-agarose affinity chromatography resulted in activation of the enzyme, suggesting the presence of an endogenous inhibitor which was detached by binding to the Reactive Dye. Immunoblots and analysis of immunoprecipitated protein revealed two bands of molecular masses approx. 111 kDa and 97 kDa. It is concluded that pancreatic ER Ca2+,Mg(2+)-ATPase is of the SERCA-2b type and consists of two isoforms.

Amino Acid Sequence↗
PubMed1993

Postoperative endophthalmitis resulting from prosthesis contamination in a monocular patient.

Monocular patients who wear an ocular prosthesis may harbor pathogenic conjunctival flora both in the socket and in the contralateral eye. They may therefore be at increased risk of developing endophthalmitis after intraocular procedures. We studied a monocular, prosthesis-wearing, 86-year-old man who underwent cataract extraction, subtotal transpupillary vitrectomy, and intraocular lens insertion. Fulminant endophthalmitis ensued postoperatively, and despite complete vitrectomy and administration of intraocular antibiotics, the eye lost light perception. Intravitreal as well as conjunctival cultures bilaterally grew Proteus mirabilis. The patient disclosed that he cleaned the prosthesis frequently because of discharge. We considered an association between this bacterial colonization and the risk of developing postoperative endophthalmitis and suggest prophylactic measures for treatment of monocular patients undergoing intraocular procedures.

Aged↗
PubMed1993

Community care and the fundholder.

According to the government, clearly agreed local arrangements should enable individual general practitioners to make their full contribution to the new system of community care without getting involved in extra bureaucracy. From 1 April the main part of that contribution will be to refer to social services those patients who seem to need social care. Many general practitioners are worried that such referrals will be complex and time consuming and will generate too much extra work. Moreover, general practitioners may also be asked to see patients specifically to help social workers' assessment procedures, and many fear that such consultations will overwork and underpay them. General practitioner fundholders already use contracts to spell out what they expect from hospital services. From 1 April they will be able to set up contracts for community health services such as district nursing and chiropody, and possibly this might be extended to social aspects of community care. Over the past 14 months Dr Rhidian Morris and his partners in a fundholding practice in Devon have piloted contracts for all aspects of community care. In this article Dr Morris explains how the most radical part of the pilot project--the contract for social care--was set up. He argues that the lessons on communication that came from what was essentially a fundholding project could apply also to non-fundholding practices.

Community Health Services↗