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Biomedical subjects

S Jackson

Publications and source records attributed to S Jackson.

At least 181 records · Page 10Linked to original sources
PubMed1996

Smoking among disadvantaged women: causes and cessation.

This study aimed to identify social-psychological factors associated with smoking and smoking cessation among disadvantaged women. Individual and group interviews were conducted with disadvantaged women in Atlantic Canada. Participants were predominantly poor, unemployed, geographically isolated, and single parents. The factors associated with smoking included coping with stresses, loneliness, powerlessness, low self-efficacy, social pressures, and addiction. Support from peers (i.e., women in similar circumstances) and partners was considered important. Health professionals and traditional cessation programs were not perceived as supportive. Participants viewed women's centres and women's agencies as appropriate deliverers of cessation programs. Methodological issues are discussed.

Adaptation, Psychological↗
PubMed1996

High prevalence of chronic gastrointestinal symptoms in a National Guard Unit of Persian Gulf veterans.

OBJECTIVES: To determine the prevalence and spectrum of GI complaints in a group of Persian Gulf veterans (PGV) and to compare these data to a group of veterans (controls) from the same unit who were not deployed to the Persian Gulf region. METHODS: A 68-item survey was distributed to 136 members of a single National Guard Unit. The survey asked the veterans to rate the frequency of GI symptoms before, during, and after the Persian Gulf war had concluded. The participants were also asked to rate frequency of 10 non-GI symptoms at the time of this survey. RESULTS: Fifty-seven PGV and 44 nondeployed veterans participated in the survey. Before the Persian Gulf war, both PGV and control groups reported low frequencies of GI symptoms. A majority of the PGV experienced GI symptoms during their deployment to the Gulf region, which persisted after their return to the United States. There were many significant differences observed between the two groups in frequency of both GI and non-GI symptoms. The greatest differences seen were for excessive gas, loose or greater than three stools per day, incomplete rectal evacuation, and abdominal pain. CONCLUSIONS: A high prevalence of chronic GI symptoms exists in this group of PGV and is significantly greater than a group of controls. The most prevalent chronic GI symptoms are those that have been associated with functional GI disorders. However, the abrupt onset and clustering in this group suggests that nonfunctional etiologies may be contributing factors.

Adult↗
PubMed1995

Characterisation of a novel enzyme of human fatty acid beta-oxidation: a matrix-associated, mitochondrial 2-enoyl-CoA hydratase.

We present evidence for the existence of a previously unrecognised enzyme of mitochondrial beta-oxidation in man. This enzyme, which is situated in the mitochondrial matrix and has medium- and long-chain 2-enoyl-CoA hydratase activity, was identified by studying tissues from a patient with a severe deficiency of the trifunctional protein of mitochondrial beta-oxidation. The novel enzyme is present in all tissues studied--heart, liver and cultured skin fibroblasts--but is particularly active in liver. Together with other recently identified enzymes of mitochondrial beta-oxidation, the existence of this new enzyme suggests that two mitochondrial beta-oxidation enzyme systems exist in man: one associated with the mitochondrial membrane, responsible for the beta-oxidation of long-chain fatty acids and one in the mitochondrial matrix, responsible for the oxidation of medium- and short-chain fatty acids.

Cells, Cultured↗
PubMed1995

High prevalence of serum IgA HIV-1 infection-enhancing antibodies in HIV-infected persons. Masking by IgG.

IgA and IgG purified from sera of 20 HIV-infected persons were separately examined for ability to mediate Ab-dependent enhancement (ADE) of HIV-1 infection of U937 cells. Both isotypes were capable of enhancing infection of these cells. However, IgA from twice as many persons (14/20) displayed infection enhancement when compared with IgG. This activity was predominantly observed with IgA from asymptomatic HIV-seropositive subjects (9/9). Enhanced HIV infection by IgA was observed most often at concentrations equivalent to serum dilutions in the range 10(-3) to 10(-5) and could be inhibited by preincubation of U937 cells with a mAb specific for the Fc alpha receptor. Concentrations of IgG mediating ADE were generally present in sera at dilutions from 10(-4) to 10(-6). When IgG was adjusted to physiologic concentration and combined with an enhancing concentration of IgA, enhancement was not observed unless IgG was also present at a concentration which exhibited this activity. These results suggest that, in comparison with IgG, HIV-infected individuals more often produce IgA Abs reacting with enhancing determinants of HIV. IgA-mediated ADE of HIV infection may not play a significant role in facilitating systemic dissemination of HIV because of the presence of higher concentrations of IgG. However, the production of IgA HIV-enhancing Abs at mucosal sites, where fewer IgG plasma cells are present, could contribute to the pathogenesis of HIV infection and interfere with development of vaccines designed to induce HIV IgA Abs at mucosal surfaces.

Cell Line↗
PubMed1995

A polarized human endometrial cell line that binds and transports polymeric IgA.

We have demonstrated that a human endometrial cell line, HEC-1, maintains a transepithelial electrical resistance, directionally transports fluids across the cell monolayer, and releases enveloped viruses at distinct plasma membrane domains: influenza virus is released at the apical surfaces and vesicular stomatitis virus (VSV) at the basolateral surfaces. In addition, we have examined the expression of domain-specific endogenous proteins, including the polyimmunoglobulin receptor. Multiple endogenous polypeptides were found to be secreted into the culture medium at basolateral surfaces, whereas no secretion of specific polypeptides was observed from apical cell surfaces. Distinct patterns of endogenous proteins were also observed on apical and basolateral cell surfaces, with a much more complex polypeptide pattern on the basolateral membranes. Using surface biotinylation and immunofluorescence, the polyimmunoglobulin receptor was found to be expressed on the basolateral surface of HEC-1 monolayers. The specific binding of poly-immunoglobulin A (pIgA) was found to occur on the basolateral surface, and was followed by transcytosis to the apical surface and release into the apical medium. The observed characteristics indicate that the endometrium-derived HEC-1 epithelial cell line can be employed as a model for studies of protein transport in polarized epithelial cells of human endometrial tissues, as well as for studies of the interaction of microorganisms with epithelial cells in the genital tract.

Biological Transport↗
PubMed1995

Intestine fullness influences feeding behaviour and crop filling in the domestic turkey.

Image-intensification radiology showed that artificial introduction of food slurry into the intestines of 6-12 wk-old turkey hens significantly increased the proportion of boli entering the crop during an evening meal, hence decreasing the proportion of boli travelling directly to the gizzard. Since bolus movement is directed by esophageal motility, esophageal motility may be partially mediated by stretch or chemoreceptors in the distal duodenum. Increased crop filling during afternoon meals lends support to the widely held belief that the crop increases gut storage capacity and helps "tide birds over" the nightly fast. Artificial filling of the distal duodenum paradoxically increased food intake in birds observed by radiology while eating a single meal (morning and evening), and in birds observed by eye over a 3 h period in the morning. This phenomenon is similar to that previously reported for rabbits and domestic chicken. Conversely, duodenal filing reduced food intake over a full day (11 h), more than compensating for the introduced food. Rapid filling of the small intestine (within 25 min. of the start of the meal) suggests a modification of the function of the domestic turkey duodenum to serve as a "mixing chamber," possibly enhancing digestive efficiency. The ways in which this modification affects digestion and absorption in the duodenum warrant investigation.

Animals↗
PubMed1995

Trisomy 18: first-trimester nuchal translucency with pathological correlation.

Diagnosis of trisomy 18 was made following prenatal screening at 11 weeks' gestation for ultrasonographically detected nuchal translucency and subsequent chorionic villus sampling. An intact fetus was therapeutically aborted and pathological examination was undertaken. We conclude that, although the etiology of nuchal translucency remains unclear, it does not appear to be lymphatic or cardiac in origin.

Adult↗
PubMed1995

The fate of the osteotomized free radial forearm osteocutaneous flap in mandible reconstruction.

The radial forearm osteocutaneous free flap has become a standard method of mandible reconstruction. In order to improve the contour of the reconstructed jaw in large resections, especially the anterior defect, the radial forearm bone graft needs to be osteotomized. The bone graft is nourished by small branches of the radial artery via the fascial connections between the skin flap and bone. The effect of the osteotomy, fixation devices, and the angulation of the bone segment on bone viability and eventual bone healing is not known. Forty-two radial forearm osteocutaneous flaps were used for composite mandible reconstruction. In 25 patients, the bone graft required osteotomy to achieve contour, of which 16 required single osteotomy and nine required double osteotomy. In a remaining 17 cases, no osteotomy was performed. Only those patients who had at least a 1-year follow-up were included in this study. The proportion of patients who achieved bone union was similar for both groups (i.e. osteotomy vs. nonosteotomy). Performing osteotomies on the segment of the radius in free osteocutaneous transfers is safe, and it allows for more flexibility in reconstruction, to achieve a natural-appearing jaw.

Adult↗
PubMed1995

Ribotyping of nosocomial methicillin-resistant Staphylococcus aureus isolates from a Canadian hospital.

OBJECTIVE: To evaluate the clonality of methicillin-resistant Staphylococcus aureus (MRSA) strains among hospitalized patients. SETTING: University-affiliated, 465-bed tertiary-care teaching hospital with adjacent cancer clinic in Hamilton, Ontario, Canada. DESIGN: Thirty-five colonized and 30 infected patients from January 2, 1992, through August 31, 1993, were investigated retrospectively. Analysis by restriction fragment-length polymorphisms of ribosomal RNA genes (ie, ribotyping) of 103 nosocomial isolates of MRSA from these 65 patients and of 25 selected unrelated strains was completed. Ribotyping results were compared with the phage typing data obtained prospectively during the course of prospective MRSA surveillance. RESULTS: HindIII ribotyping was more discriminating than phage typing when epidemiologically unrelated strains were differentiated by these methods (19 different ribotypes versus 14 page types; P < .005). Two early index cases were identified. Isolates from the index cases were two different strains, identified by ribotyping analysis as ribotype A (clonal group 1) and ribotype B (clonal group 2), respectively. These two ribotypes were not found when typing the unrelated control strains. Thirty-six colonized and infected patients (55%) had clonal group 1 isolates, and 20 (31%) had clonal group 2 isolates. These two clones emerged in the hospital in January and February 1992 and dominated the entire investigated period. There also were six patients with an additional clonal group (group 4) that emerged and disappeared in the second quarter of 1993. CONCLUSIONS: This study highlights the utility of ribotyping in investigating nosocomial MRSA. Three MRSA clones caused nosocomial colonization or infection in patients at this hospital. Two of these MRSA clones, once introduced, were maintained among our patients throughout the study period.

Bacteriophage Typing↗
PubMed1995

Establishing a district palliative care team for children.

The children's palliative care team aims to ensure a high standard of care and support for children with life-threatening illnesses and their families. The team works through primary care teams and with hospital staff to ensure consistency and continuity of care and to maintain awareness of good practice and acts as a resource for staff from independent and voluntary agencies. The team consists of a consultant community paediatrician, clinical child psychologist, a dedicated social worker, sick children's trained district nurse, a senior member of staff from the children's ward, a health visitor, a school nurse, and a special school nurse. Other professionals are co-opted to the team as and when considered necessary, for example hospice consultant, pain specialist, dietician, paediatric pharmacist, chaplain. This paper describes how the children's palliative care team was set up and the first 2 years of its functioning.

Child↗
PubMed1995

Generation of monoclonal antibodies to Macaca mulatta (rhesus) IgA.

One IgG1 and five IgM murine monoclonal antibodies (mAb) specific for rhesus (Rh) IgA were generated. These mAbs bound to Rh IgA but not IgG or IgM when tested by enzyme-linked immunosorbent assay. Immunoblotting revealed that the mAbs reacted with the alpha heavy chain of Rh but not human IgA. The IgG1 anti-Rh IgA mAb detected IgA-producing cells in sections of monkey gut examined by immunofluorescent staining. These mAbs should be useful for characterizing IgA responses in the Rh monkey.

Animals↗
PubMed1995

High-throughput screen for detecting antimycobacterial agents.

A simple, robust assay system which can be used to screen for inhibitors of mycobacterial growth has been developed. A strain of the rapidly growing saprophyte Mycobacterium aurum is used as the test organism. Inhibition of its growth is highly predictive of activity against Mycobacterium tuberculosis, which cannot itself be used in screening because of its growth characteristics and highly infectious nature. The viability of M. aurum in the presence of a test sample is monitored by measuring the uptake of radiolabelled uracil into the cells. In a microtiter plate format, the screen has the potential for testing several thousand samples per day.

Antitubercular Agents↗
PubMed1995

Bacillus cereus phage typing as an epidemiological tool in outbreaks of food poisoning.

Bacillus cereus is responsible for an increasing number of food poisoning cases. By using 12 bacteriophages isolated from sewage, a typing scheme for B. cereus isolates from outbreaks or sporadic cases of food poisoning was developed. The phages belonged to three morphotypes. Ten phages with contractile tails and icosahedral heads were members of the Myoviridae family, and two phages with noncontractile tails belonged to the Siphoviridae family. Phage 11 represented a new species. It had an isometric head and a very long contractile tail with long wavy tail fibers and was one of the largest viruses known. The vast majority of 166 B. cereus strains (161, or 97%) isolated from food poisoning cases were typeable. Of 146 strains isolated from 18 outbreaks, 142 (97%) could be divided into 17 phage types. A good correlation, on the order of 80 to 100%, between phage types of strains isolated from suspected foods and those of strains isolated from stools of symptomatic patients was observed. Most Bacillus thuringiensis strains were also typeable, providing further evidence of the close relatedness of B. cereus and B. thuringiensis. This phage typing scheme can be a valuable epidemiological tool in tracing the origins of food poisoning caused by B. cereus.

Bacillus Phages↗