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Biomedical subjects

R Black

Publications and source records attributed to R Black.

At least 55 records · Page 3Linked to original sources
PubMed1994

The effects of growth hormone-releasing factor on food consumption in anorexia nervosa patients and normals.

Current evidence from animal studies indicate that growth hormone-releasing factor (GRF) has direct effects on mechanisms controlling eating behavior. There is also evidence that eating disorder patients have abnormalities in their GRF-growth hormone (GH) axis. The present study investigated the possibility that GRF abnormalities contribute to the expression of abnormal eating patterns in anorexia nervosa (AN) patients, and that GRF has therapeutic potential in this regard. To this end, patients diagnosed with anorexia nervosa or combined anorexia nervosa/bulimia nervosa (AN/BN), as well as normal female subjects, were tested for their eating and GH responses following intravenous infusion of GRF (1 micrograms/kg) or placebo. Results indicated that GRF stimulates food consumption in AN patients and attenuates the elevated food consumption in AN/BN patients. These results are consistent with the notion that GRF abnormalities contribute to abnormal eating behavior, and provide preliminary evidence for the therapeutic potential of GRF in such conditions. The extent to which the present effects of GRF are dependent on nutritional status, GH actions, or direct central actions of GRF, are discussed.

Adult↗
PubMed1994

Orientation of Listing's plane in normals and in patients with unilateral vestibular deafferentation.

The parameters characterizing Listing's plane have been determined in a group of normal subjects, and in patients who have had unilateral vestibular deafferentation on the right or left side. All patients were well compensated. There was no statistically significant difference in the orientation of Listing's plane between either of these groups: Listing's plane was approximately perpendicular to the horizontal stereotaxic plane and showed a systematic temporal tilt, i.e., it tilted right for the right eye, and left for the left eye. We also found a considerable intersubject variability in the orientation of Listing's plane. The effect of this variability on the interpretation of three-dimensional eye position and velocity data is discussed.

Denervation↗
PubMed1994

Biofeedback re-education of faecal continence in children.

The purpose of this prospective study was to see if pretreatment anorectal motility can predict successful correction of faecal incontinence with biofeedback. Forty-seven consecutive children, aged 5 to 18 years, were treated. They had been treated for idiopathic constipation with faecal impaction, but had remained incontinent (n = 15), had been operated for congenital anorectal malformations of high (n = 19) or low (n = 2) type, or had a number of organic congenital pelvic abnormalities (n = 11). This consecutive series represents our entire experience with biofeedback for faecal incontinence, in the period from January 1 1983 to December 31 1989. In each patient, at the first session, anorectal manometry was performed. Resting pressures in the rectum, upper anal canal and lower anal canal were measured. The threshold of rectal sensation during distension, the maximal pressure during voluntary sphincteric contraction and the time to half decrease of sphincteric pressure because of muscular fatigue were also noted. The patient was then asked to make a voluntary sphincteric contraction, while the rectum was being distended with the volume at threshold for rectal sensation. In subsequent sessions, the rectum was also distended but without warning the patient, who was congratulated when he or she contracted the sphincter immediately after onset of rectal distension. Full continence was the criterion used to classify re-education as a success. Improvement or no change in continence was considered as failure of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Environmental change in refugee-affected areas of the Third World: the role of policy and research.

This paper reviews the current nature of policy responses to environmental change in refugee assistance programmes. Based on a review of existing documentary material and a survey of UK-based NGOs, it is suggested that although refugee assistance agencies are aware of environmental issues, this is rarely translated into effective policy measures to identify and combat environmental degradation. Various existing methods used to calculate environmental impacts are considered, but a number of pitfalls are identified. It is suggested that little is known about the processes that lead to accelerated environmental change in situations of forced displacement, and that research providing deeper understanding of local environments and resource management systems is required for environmental policies to be effective.

Developing Countries↗
PubMed1994

Refugee migration and local economic development in Eastern Zambia.

"This article examines the local socio-economic impact of the arrival of Mozambican refugees in the Eastern Province of Zambia. Previous studies of forced migration elsewhere in Africa have suggested that not only stresses, but also positive gains for local development may be felt in areas hosting significant numbers of refugees. It is suggested here that an appropriate framework from which to analyze the impact of refugees is to focus separately on the effects of population increase on the one hand, and the specific characteristics of refugees on the other. Using this distinction, a model is developed of potential beneficial changes resulting from the arrival of refugees. Key assumptions of this model are then identified to be of relevance to policies designed to promote local economic development under conditions of refugee migration."

Africa↗
PubMed1993

Growth dynamics during the first two years of life: a prospective study in the Philippines.

This study examines determinants of growth from birth to 24 months in a sample of approximately 3000 urban and rural Filipino children. Individual, household, and community data were collected bimonthly during the Cebu Longitudinal Health and Nutrition Survey. Separate longitudinal, multivariate models were used to identify determinants of weight in children from birth to 6 months and 6-24 months of age. Previous weight, male gender, mother's height, and season of the year showed significant positive associations with weight in all models. Full and mixed breast-feeding significantly increased weight, but the effects of breast-feeding declined as children got older. Breast-feeding had a direct growth-enhancing effect in addition to its indirect effect through the prevention of diarrheal morbidity. Detrimental effects of recent diarrheal morbidity were particularly important in the older age group, but these effects were mitigated by breast-feeding. Since infant feeding variables are included in the models, the results strongly suggest an effect of diarrheal morbidity on growth independent of its known effects on infant feeding and dietary intake. Febrile respiratory infections had important detrimental effects on weight in both age groups.

Body Height↗
PubMed1992

Frequency of late potentials on signal-averaged electrocardiograms during thallium stress testing in coronary artery disease.

Late potentials detected by signal-averaged electrocardiography (SAECG) are an important noninvasive indicator identifying patients with previous myocardial infarction at risk for developing ventricular tachycardia. The role of myocardial ischemia in the development of late potentials is undefined. This study attempts to determine if late potentials on SAECG can be produced during scintigraphically proven ischemia. A signal-averaged electrocardiogram was obtained before and immediately after single-photon emission computed tomography thallium exercise testing in 51 patients. Reversible ischemia was documented in 25 cases with no significant changes in the parameters of SAECG; patients with previous myocardial infarction (n = 10) also had no significant changes from baseline. Multivariate analysis with respect to reversible ischemia and previous myocardial infarction was unrevealing. Patients with late potentials at baseline (n = 10) who developed reversible ischemia (n = 5) had a shorter QRS duration than those with late potentials at baseline and no reversible ischemia. The data indicate that exercise-induced scintigraphically proven ischemia does not alter SAECG even in the presence of previous myocardial infarction. Patients with late potentials at baseline may actually have a shortened QRS duration during reversible ischemia as opposed to the expected lengthening of the QRS.

Coronary Disease↗
PubMed1992

Theory-driven behavioral intervention research for the control of diarrheal diseases.

Essentially all methods to reduce diarrheal morbidity and mortality require behavioral change. Research is required to design, implement and evaluate behavior-modifying interventions. Accumulated experience in the many involved disciplines should serve as a basis for this research. However, each of these disciplines is associated with different research perspectives and analytic assumptions; thus integration of these varied but potentially complementary experiences has been elusive. In the present paper, arguing that such perspectives and assumptions are embodied in discipline-based theory, we have developed a generic framework for the conduct of theory-based behavioral intervention research. We illustrate the application of this framework through two vignettes applying two of the theories and models to the development of hypothetical handwashing interventions.

Behavior Therapy↗
PubMed1992

Panniculus morbidus.

Eight patients with large panniculi are described where severe problems with hygiene, immobility, and chronic infection were caused by the lymphedematous, chronically infected pannus. Protracted nonsurgical management of the infected panniculus had failed in all 8 patients. Wedge resection without fat undermining removed diseased tissue. Infection and sepsis were eliminated and ambulation was restored in all patients. Formerly immobile patients were returned to normal activity. Significant self-induced weight loss was not observed in a 2-year follow-up period; weight gain, however, was not experienced. The primary anesthetic method was thoracic epidural reducing the requirements for general endotracheal anesthesia. The chronically infected pannus is a surgical problem deserving earlier recognition and resection.

Abdomen↗
PubMed1992

A probe for specimen magnetic resonance microscopy.

One of the primary limits to spatial resolution in magnetic resonance (MR) microscopy is the limited signal. The purpose of this study is to build a radiofrequency (rf) probe for MR microscopy of fixed specimens at 300 MHz. The design criteria for the probe were (1) high sensitivity; (2) good rf homogeneity; (3) minimization of BO variations. All probes were Helmholtz pairs operating at 300 MHz. Coils were constructed from copper/Teflon/copper microwave substrate which eliminated susceptibility problems from solder and discrete capacitors. Signal-to-noise ratio (SNR) was compared with a conventional solenoid. Phantoms of agar gels and saline-filled tubes were used to characterize the SNR and homogeneity. SNR measurements of the coil pairs showed a marked improvement (up to 60%) over that of the reference solenoid. The region of homogeneity was defined as a 10% variation in signal intensity. This correlated with the coil's inner diameter. Graphs of SNR versus diameter, separation, and copper foil width allowed for optimization of the structure. Using this coil, MR microscopy is now possible on small, fixed specimens with pixels as small as 20 x 20 x 30 microns. Work is currently under way exploiting the SNR and homogeneity provided by this probe to determine the degree to which MR microscopy might add to the pathologists' diagnostic tools.

Copper↗
PubMed1992

Graphic summaries of expert knowledge for the medical curriculum: an experiment in second-year nephrology.

This study was conducted to test the effects of Concept Graphics on learning in clinical nephrology. Second-year medical students were exposed to summaries of the major renal pathologies presented as text with, or without Concept Graphics for 30 minutes, followed by a quiz. Concept Graphics summarize diagnoses using icons that are metaphors of objects or processes. Of nine quiz questions, five were classified as correlation questions and four as memorization questions. The experimental group (n = 39) performed better than the controls (n = 33) in answering the correlation questions (p = 0.018). The experimental group mentioned more frequently than the controls two pathogonomic criteria of the nephritic syndrome (p = 0.02). Results of an opinion poll of the students, comparing sources used in their studies of nephrology were treated by correspondence analysis; the Concept Graphics ranked closest to the classification "very useful".

Computer Graphics↗
PubMed1991

Effects of indomethacin on prostaglandin E2 and thromboxane B2 contents of tracheal lavage fluids in premature infants.

A prospective longitudinal study was conducted in 14 premature infants intubated and receiving ventilatory support from birth, in order to evaluate the levels of prostaglandins E2 (PGE2) and thromboxane B2 (TxB2) in the tracheal lavage fluids (TLF) after treatment with indomethacin. Eight were treated with indomethacin, a cyclooxygenase inhibitor, for patient ductus arteriosus and the others served as controls. Infants who received indomethacin during the first postnatal week had significantly lower levels of eicosanoids in TLF during the first week. Our results suggest that levels of eicosanoids in TLF of premature infants are related to an inflammatory reaction and may serve as an index of the infant's overall clinical condition.

Body Fluids↗
PubMed1991

Peri-operative colonoscopy detects synchronous tumours in patients with colorectal cancers.

The aim of this study was to assess the value of colonoscopy as a peri-operative investigation in patients treated for colorectal cancer by surgical excision. Patients (134 male, 83 female) undergoing curative resection for colorectal carcinoma between August 1984 and January 1989 had colonoscopy within 3 months of surgery. Eleven patients (5%) had a synchronous cancer, which was diagnosed by colonoscopy in eight. In six of these eight, the diagnosis was made after surgery and 3 patients needed a second colectomy. However, in 3 patients the synchronous cancer was removed endoscopically without the need for further surgical resection. Most synchronous cancers had an earlier pathological stage than the index tumour. The rate of synchronous cancers was higher in patients with synchronous benign polyps (16%) than in those without polyps (3%). Colonoscopy is clearly justified as a peri-operative investigation in all patients undergoing potentially curative resection of colorectal cancer. If possible, the examination should be carried out prior to surgery, to guide the extent of resection.

Adult↗