Search PubMed⌕ Search

Biomedical subjects

J Wallace

Publications and source records attributed to J Wallace.

At least 73 records · Page 4Linked to original sources
PubMed1995

A telemedicine transaction model.

The objective of this paper is to propose a telemedicine transaction model and a set of terms to facilitate communication between telemedicine researchers, program directors, and others. The model is described in terms of the sites, personnel, and events involved. Examples of real-time, store-and-forward, and physical referral transactions are depicted using the model. A hierarchy of information classes for collaboration studies is developed based on their relation to the frequency of data collection. Finally, a list of definitions is given to specify the terminology used. The model is suitable for most telemedicine systems, is useful in providing a common language for skilled telemedicine participants, and can be used in comparative evaluation studies.

Communication↗
PubMed1995

Age-related differences in the symptomatic expression of major depression.

Hamilton Rating Scale for Depression and Beck Depression Inventory results were examined in a consecutive series of 174 female and 83 male patients, ranging in age from 18 to 81 years, admitted to a psychiatric hospital with a diagnosis of major depression. Items on the two scales were examined to determine the relationship between age and the symptomatic expression of major depression. Overall scores on the Hamilton scale revealed no relationship with age, but scores for males on the Beck Depression Inventory were negatively associated with age. In addition, the most prevalent types of depressive symptoms showed significant correlations with age. Items related to low self-esteem, such as guilt, sense of failure, self-accusations, and thoughts of suicide, showed a negative relationship with age for both males and females. It is possible that psychological maturation or other age-related factors reduce vulnerability to low self-esteem during episodes of clinical depression; however, selection bias or a cohort effect cannot be ruled out with the current methodology.

Adolescent↗
PubMed1995

Complications of bush thoracotomy in the Highlands of Papua New Guinea.

Bush thoracotomy is still practised in the South Western Highlands of Papua New Guinea, by traditional bush doctors. These bush thoracotomies are performed with the aim of letting out the 'bad blood' that is believed to have collected in the body cavities following injuries. During a 3 year period between 1989 and 1992, 183 patients with complications of bush thoracotomy were treated at the Sopas Hospital in the Highlands of Papua New Guinea. Of these patients, 55 had chest wall infections only, without any pleural involvement. Of the patients with empyemas, 14 were treated by decortication of the empyema with one death and all remaining patients were treated by drainage procedures with one death. We recommend early treatment by adequate drainage of the empyema and, where feasible, early decortication. Continuing education to eradicate the procedure, and provision of adequate surgical facilities for management of complications, should be the long-term aim for this continuing problem.

Adolescent↗
PubMed1995

A positive, individually ventilated caging system: a local barrier system to protect both animals and personnel.

Most local barrier systems are designed primarily either to protect animals from airborne contamination (exclusion) or to ensure the safety of personnel (hazard containment). Few, other than isolators, are able to cope with the often conflicting demands to do both. The Positive Individually Ventilated system (PIV), which provides pressure adjustable, individual supply and exhaust ventilation to each cage has been tested with this in mind as well as the need to ensure that environmental conditions comply with the requirements of the Home Office Code of Practice (CoP). The results indicate that when compared with traditional open racking the system can reduce both the risk of animals becoming contaminated by airborne infection from the room and the risk of aeroallergens escaping from the cages into the room air. At the same time, environmental conditions within the cages are both less variable and less stressful to the occupants. Conditions of air temperature, relative humidity, ventilation rates, light intensity and (with appropriate air handling) sound levels, all comply with or are better than those required by the CoP. Even with the room air change rate set at only 8/h (8 ac/h) the air distribution system results in draught-free cage ventilation rates of around 50-120 ac/h. This means that with at least the PIV exhaust(s) linked directly into the air conditioning system of the building, the size of the latter and its associated running costs can be reduced by around 50%; this energy saving concept has been approved in principle by the Home Office. Additional benefits include the fact that bedding is kept much drier allowing further cost savings in bedding and associated labour costs. The system is thus beneficial to the animals in protecting them from airborne infection and other stresses. By providing a less variable environment it also helps to minimise the sort of interference with experiments which can arise from that source. Similarly, in accordance with the aims of 'The Control of Substances Hazardous to Health Regulations' (COSHH 1988) and the Health & Safety Executive (HSE 1990), by reducing dust levels in the room air, including allergens, it is also beneficial to the personnel working in the animal rooms.

Air Pollutants, Occupational↗
PubMed1994

Modulation of host response to Escherichia coli o157:H7 infection by anti-CD18 antibody in rabbits.

BACKGROUND/AIMS: Escherichia coli O157:H7 infection induces diarrhea, severe colitis, and colonic electrolyte transport abnormalities characterized by decreased Na absorption and Cl secretion. The aim of this study was to examine the role of the host inflammatory response in inducing distal colonic transport changes during infection with E. coli O157:H7. METHODS: New Zealand white rabbits aged 10 days were infected with E. coli O157:H7 strain EDL933 (plasmid+, verotoxin 1+, verotoxin 2+). Studies were performed daily from day 1 to day 5 postinfection and compared with uninfected controls (10 days old). Distal colonic ion transport was studied in vitro under short-circuited conditions in Ussing chambers, and tissue inflammation was assessed by mucosal myeloperoxidase activities and mucosal neutrophil (polymorphonuclear neutrophil [PMN]) counts. In a second study, PMN infiltration was inhibited by an anti-CD18 (leukocyte adhesion molecule) monoclonal antibody, IB4, and histology and transport were studied on day 5 postinfection. RESULTS: Infection with O157:H7 induced diarrhea and inhibition of Na absorption by day 3. CI secretion occurred on day 5, coincident with tissue infiltration with PMN. Pretreatment with IB4 prevented histological damage and tissue infiltration with PMN, and it inhibited the transport abnormalities induced by infection alone. CONCLUSIONS: Infection with O157:H7 reduces Na absorption and stimulates Cl secretion in the distal colon. Disruption of the epithelium and changes in colonic electrolyte transport during enterohemorrhagic E. coli are mediated by the host inflammatory response.

Animals↗
PubMed1994

Hartnup disease presenting in an adult.

A young woman presented with pellagra. Her symptoms were precipitated by prolonged lactation and increased activity. Dietary intake of niacin was within recommended guidelines. Chromatography of urinary amino acids was diagnostic of Hartnup disease, an inherited disorder usually presenting in childhood. Her symptoms resolved with oral nicotinamide.

Adult↗
PubMed1994

Intestinal anaphylaxis: radiation-induced suppression.

The gastrointestinal tract is highly sensitive to ionizing radiation. Some of the most radiosensitive cells in this system are mast cells and epithelium. This article describes experiments that test the hypothesis that irradiation suppresses mucosal immune responses in which mast cells and epithelium are involved. The hypothesis was tested by examining the impact of ionizing radiation on anaphylactically mediated Cl- secretion in jejunum of rats sensitized by Trichinella spiralis infection and challenged with antigen derived from the parasite. Antigen-induced Cl- secretion was measured electrophysiologically in vitro. Rats were immunized by inoculation with 3 x 10(3) T. spiralis larvae and, 30-50 days later, exposed to total abdominal irradiation from a cobalt-60 gamma source. Doses were 5, 7, and 9 Gy. At 1, 3, 5, 7, 14, and 21 days postirradiation (DPI), jejunal segments were assessed for immune responsiveness. (Duration of suppression to antigenic challenge was directly related to radiation dose). Recovery of response to antigenic challenge after irradiation with 5 Gy was complete by 5 DPI. At 7 Gy, responsiveness was totally suppressed from 1 to 5 DPI, was partially expressed from 5 to 14 DPI, and was completely restored by 21 DPI. A dose of 9 Gy completely suppressed immune responsiveness throughout the 21-day period. Full responsiveness of jejunum to exogenous Cl- secretagogues at 1-5 DPI indicates that the immunosuppressive effect of radiation was not due to a breakdown in the secretory process at the epithelium level.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaphylaxis↗
PubMed1993

Instructions in learning skills: an integrated approach.

The transition from school to university education and a medical school environment can be difficult even for the very best students. However, little appears to be done to assist students in making this transition and in developing study skills during the early stages of their training. This article outlines a scheme which has been called supplemental instruction. Although developed for medical students in the United States, it is particularly well suited to developing essential study skills in first-year medical students in the United Kingdom. The scheme has been successfully introduced into some degree and diploma subjects in this country, with improvement in course grades and lower attrition rates, but has yet to be introduced into medical education. Evaluation data for non-medical courses show that student participation in supplemental instruction significantly improves overall course marks and could be of significant value in the medical curriculum.

Counseling↗
PubMed1993

Kangaroo care.

Kangaroo Care--skin-to-skin contact between parent and baby--is becoming a popular adjunct to the routine, technology-driven care provided to premature babies in neonatal intensive care units (NICUs) across the country. Research suggests that Kangaroo Care is safe and that it is therapeutic for the infant and parent alike. The purpose of this article is to review the Kangaroo Care Program at Brigham and Women's Hospital and to illustrate how it meets the needs of parents of premature infants.

Boston↗
PubMed1993

Primary gastric adenosarcoma.

We describe the first case, to our knowledge, of a primary gastric adenosarcoma surgically resected from a 46-year-old white man. This biphasic neoplasm, well described in the female genital tract, was composed of cytologically benign tubular and cystic glands widely dispersed within a sarcomatous stromal component. Immunohistochemically, the epithelial elements were positive for cytokeratin, while the stromal elements were positive for vimentin and desmin. The clinical and pathologic features of pelvic adenosarcomas are described and compared with the tumor of the stomach. Although accurate prediction of the biologic behavior of this gastric neoplasm is difficult, the high mitotic rate in the sarcomatous component and the infiltration of the gastric serosal surface by the tumor were considered to be ominous prognostic features.

Humans↗
PubMed1992

Modulation of leukocyte adhesion in rat mesenteric venules by aspirin and salicylate.

Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and number of adherent and emigrated leukocytes were measured in postcapillary venules both before and during superfusion of rat mesentery with either aspirin or sodium salicylate. In some experiments, animals were treated with either a leukotriene (LT)-synthesis inhibitor (L-663,536), an LTD4 antagonist (MK-571), an LTB4 antagonist (SC-41930), misoprostol, or prostaglandin (PG) I2, then the aspirin protocol was repeated. Superfusion of aspirin but not sodium salicylate resulted in increased leukocyte adherence and a reduced leukocyte rolling velocity but did not affect leukocyte emigration. Aspirin-induced leukocyte adhesion was effectively prevented by the LT-synthesis inhibitor and LTB4 antagonist but not by the LTD4 antagonist. Misoprostol and PGI2 also prevented the aspirin-induced adhesion responses. Superfusion of the mesentery with either platelet-activating factor (PAF) or LTB4 enhanced leukocyte adherence and emigration while reducing leukocyte rolling velocity. Sodium salicylate prevented all of the adhesion responses elicited by LTB4. Although salicylate did not affect the PAF-induced leukocyte adherence and rolling responses, it completely prevented the increased leukocyte emigration. These results indicate that aspirin promotes, whereas sodium salicylate inhibits, leukocyte-endothelial cell adhesive interactions at therapeutically relevant concentrations.

Animals↗
PubMed1992

Force-length properties and functional demands of cat gastrocnemius, soleus and plantaris muscles.

The purpose of this study was to measure isometric force-length properties of cat soleus, gastrocnemius and plantaris muscle-tendon units, and to relate these properties to the functional demands of these muscles during everyday locomotor activities. Isometric force-length properties were determined using an in situ preparation, where forces were measured using buckle-type tendon transducers, and muscle-tendon unit lengths were quantified through ankle and knee joint configurations. Functional demands of the muscles were assessed using direct muscle force measurements in freely moving animals. Force-length properties and functional demands were determined for soleus, gastrocnemius and plantaris muscles simultaneously in each animal. The results suggest that isometric force-length properties of cat soleus, gastrocnemius and plantaris muscles, as well as the region of the force-length relation that is used during everyday locomotor tasks, match the functional demands.

Animals↗
PubMed1992

Increases in soluble CD8 antigen in plasma, and CD8+ and CD8+CD38+ cells in human immunodeficiency virus type-1 infection.

Increases in plasma levels of soluble CD8 (SCD8) antigen and expansion of the CD8+ CD38+ lymphocyte compartment were early immunologic alterations frequently observed prior to detection of antibodies against human immunodeficiency virus type 1 (HIV-1) and diminution of CD4+ cells in subjects at risk to develop AIDS. These increases identified in the 49 seronegative homosexual men were manifest in all 164 homosexual subjects and 45 intravenous drug users (IVDU) positive for HIV-1 antibodies (HIV-1+), 19 patients with ARC, and 29 AIDS patients. Augmentation of plasma sCD8 antigen correlated with increases in both CD8+ and CD8+ CD38+ cells in HIV-1(-) homosexual men (r = 0.35, P less than 0.013; r = 0.48, P less than 0.0005; respectively) and the 258 HIV-1+ subjects (r = 0.25, P less than 0.0003; r = 0.33, P less than 0.0001, respectively). In vitro examination of unstimulated peripheral blood lymphocytes from HIV-1+ homosexuals and IVDU confirmed the fivefold higher constitutive levels of cellular release of sCD8 antigen in these subjects compared to heterosexual controls. Inclusion of radiolabeled amino acids during the 3-day culture period in the presence or absence of phytohemagglutinin resulted in negligible levels of radioactivity associated with the sCD8 antigen indicative of a lack of de novo synthesis. Throughout clinical progression to AIDS, sCD8 antigen levels continued to escalate relative to the numbers of CD8+ cells bearing CD38+ antigen. The data confirm the interrelationship between sCD8+ antigen and CD8+ and CD8+ CD38+ cells.

ADP-ribosyl Cyclase↗
PubMed1992

Long-term treatment with gabapentin for partial epilepsy.

Gabapentin was studied as an open-label 'add-on' antiepileptic drug in 35 patients with partial seizures. Follow-up at 6 months, 12 months, 18 months, and 24 months is reported. There was a trend toward improvement in simple (SPS) and complex partial seizures with it reaching significance for SPS at 12 and 24 months and for the weighted combination of seizures at 3 months. Five of nine patients were subsequently successfully converted to gabapentin monotherapy. Of those five, one is now seizure free and three are significantly improved since baseline. One remains with unchanged seizure frequency compared to baseline, but is experiencing less toxicity than at that time. This long-term observation suggests that the short-term effect demonstrated in blinded studies continues and that indeed some patients with refractory epilepsy can be maintained on gabapentin alone. Based on these findings, double-blind monotherapy trials of this drug are presently being conducted.

Acetates↗
PubMed1992

Increases in depressive symptomatology in the rural elderly: results from a cross-sectional and longitudinal study.

Depressive symptomatology was examined in a large sample of noninstitutionalized older adults using the Center for Epidemiological Studies-Depression scale (CES-D). Both cross-sectional and longitudinal data showed age-related increases in mean CES-D scores and increases in the percentage of respondents scoring at or above the cutoff score of 16. Variables collected at baseline in the longitudinal study from 2,032 participants 65 years of age and older were significant predictors of depressive symptomatology 3 and 6 years later. Baseline CES-D scores accounted for the largest proportion of the variance.

Activities of Daily Living↗