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Biomedical subjects

M B Lee

Publications and source records attributed to M B Lee.

At least 19 recordsLinked to original sources

Women's preferences for information and complication seriousness ratings related to elective medical procedures.

OBJECTIVE: To study the preferences of patients for information related to elective procedures. METHODS: A survey was carried out using a sample of 187 women. The majority of whom were on a low-income, who obtained obstetric or gynaecological services at St Joseph Regional Medical Center in Milwaukee, Wisconsin, while they were in a waiting room. RESULTS: Many of the complications, including those that are uncommon and less serious, were considered to be relevant to the medical decisions of most patients. Average seriousness ratings associated with complications of various elective procedures were in the range of moderate to high. A frequency of complications of 1:100 or higher would factor into most women's elective treatment decisions. Women indicated a preference for receiving as much or more information pertaining to complications associated with particular elective obstetric or gynaecological procedures as other elective procedures. CONCLUSION: Most women wish to be informed of risks and treatment alternatives, rate many complications as serious, and are likely to use information provided to make elective treatment decisions.

Adolescent↗

Trigonelline is not responsible for the acute increase in plasma homocysteine following ingestion of instant coffee.

OBJECTIVE: To determine whether trigonelline contributes to the effect of coffee on homocysteine (Hcy). DESIGN AND INTERVENTIONS: This was a randomised crossover study. Subjects consumed 50 mg trigonelline, 5 g of instant coffee (approximately 50 mg trigonelline) or water, consumed as a single dose in 100 ml, with 1 week between each treatment. Blood samples were drawn fasting and hourly for 8 h. Urine samples were collected pretreatment and every 2 h for 8 h. SETTING: Christchurch Clinical Studies Trust, Christchurch, New Zealand. SUBJECTS: Eight healthy male subjects. RESULTS: Instant coffee raised plasma Hcy concentrations compared with water (P=0.019) and trigonelline (P=0.037). Plasma Hcy concentrations were not different between water and trigonelline treatments (P=0.789). The change in plasma Hcy concentration was higher (mean+/-s.e.) 4 h (0.7+/-0.2 micromol/l, P=0.006), 5 h (0.7+/-0.2 micromol/l, P=0.013) and 7 h (0.7+/-0.2 micromol/l, P=0.024) following coffee consumption. Urinary glycine betaine excretion was increased by coffee but not by trigonelline. CONCLUSION: Ingestion of instant coffee acutely elevated plasma Hcy; however, trigonelline is not responsible for this rise. SPONSORSHIP: Supported by the Health Research Council, the Canterbury Medical Foundation, the Foundation of Research, Science and Technology.

Adult↗

Far-field characterization of small apertures.

A far-field method for characterizing apertures based on the relationship between the relative intensity of propagating modes in a given medium and a small aperture illuminated with a light beam is proposed. A simple optical set-up based on computer-generated holograms and spatial filters is suggested to measure the relative strength of modes and provide axial intensity measurements in the far-field zone. It is shown that the minimal size of a spot that may be measured decreases with an increase in the refractive index of a medium into which light propagates and with the use of high-order spatial mode filters. The intensities transmitted through tapered optical fibre tips have been measured and their aperture diameters determined using window-type spatial filters. The results have been compared with measurements using scanning electron microscopy.

Holography↗

Cementless acetabular replacement in patients with rheumatoid arthritis: a 6- to 14-year prospective study.

Sixty-three consecutive patients who had 82 Harris-Galante porous acetabular cups (HGP1) (Zimmer Inc, Warsaw, IN) implanted for the treatment of rheumatoid arthritis were prospectively assessed since 1986. At last examination, 12 patients (16 hips) had died, and 1 patient (1 hip) was lost to follow-up. A total of 65 hips in 50 patients were available for the latest review. The follow-up period was 6.8 years to 14 years (mean, 9.1 years). There had been 6 revisions: 1 for deep infection and 5 for polyethylene cup wear. Survivorship analysis for all failures estimated that 75% of hips would still be revision-free after 4558 days (12.5 years). Polyethylene wear has been identified in a further 7 cases at last examination. The average linear cup wear per year was 0.05 mm(range, 0.00-0.66 mm). There were no cases of acetabular loosening or acetabular migration. These results demonstrate the excellent durability of fixation of the HGP1 cups in patients with rheumatoid arthritis. However, a 32-mm head should probably not be used with this cup given the high associated incidence of polyethylene wear.

Acetabulum↗

Linking research and practice: participation of nurses in research to influence policy.

In this article, the authors describe research conducted by the Pakistan Nursing Council (PNC) in Islamabad, Pakistan. The research was carried out through collaboration of two components of a large multicomponent Canadian International Development Agency (CIDA)-funded project--the Development of Women Health Professionals Program (DWHP)--with the Colleges of Nursing and the Pakistan Nursing Council. The research was guided by staff of the DWHP and performed by eight nurses undergoing a research course as part of a Diploma in Teaching Administration (DTA) at a postgraduate College of Nursing in the Northwest Frontier Province (NWFP), Pakistan. Research questions related to the collection and analysis of nursing workforce statistics were asked and partially answered, while students gained experience in conducting research. A description of the context in which the research was conducted is provided. Finally, results of the research and the potential benefits for influencing health workforce policy are discussed.

Data Collection↗

Femoral impaction grafting in revision hip arthroplasty with irradiated bone.

We evaluated the results of femoral impaction grafting with the Exeter stem (Stryker Howmedica Osteonics, Newbury, UK) and irradiated bone-graft. We followed 57 hips for an average of 27 months. Endo-Klinik grading showed 8 grade 1, 22 grade 2, and 27 grade 3 hips. Radiographic analysis revealed cortical repair in 34% and graft incorporation in 39% but no evidence of trabecular remodeling. Moderate subsidence (5-10 mm) occurred in 7 patients (12.5%), and massive subsidence (>10 mm) occurred in 4 patients (7%). Complications included 6 dislocations, 3 periprosthetic fractures, and 2 stem revisions. Impaction grafting with the Exeter system produces satisfactory results for most patients, but a few hips perform poorly, and the reasons for this are unclear. We have concerns about irradiated bone-graft because the characteristic changes of graft remodeling are not seen.

Adult↗

Summary of stationary and personal air sampling measurements made during a plutonium glovebox decommissioning project.

Workplace air sampling was performed during the decommissioning of a previously active plutonium glovebox facility located at Argonne National Laboratory. Personal air samplers (PAS) were used to measure breathing zone activity concentrations of workers engaged in size-reducing contaminated gloveboxes. Stationary air samplers (SAS) were used to measure the work area activity concentrations and test their application in providing representative sampling of breathing zone activity concentrations. The relative response of these samplers (PAS:SAS) was tracked during the course of the decommissioning work, with results yielding favorable agreement to within a factor of +/-5. A cascade impactor was used to determine the particle size distribution of workplace aerosols. The average activity median aerodynamic diameter (AMAD) was estimated to be 3.0 microm, with a corresponding geometric standard deviation of 2.4. A gas-flow proportional counter was utilized to measure the gross alpha activity collected on both the SAS glass fiber and the PAS cellulose fiber filters. A subset of this filter group was subsequently analyzed using an alpha spectrometer post radiochemical processing and isotopic separation. The quantity of alpha activity measured on the SAS filters was generally within +/-30% of the alpha spectrometry measurements. However, measurements made of the activity present on the PAS cellulose fiber filters were consistently underestimated using a gas-flow proportional counter, suggesting a small correction factor of 15-20% to account for the absorption of alpha particle emissions.

Air Pollutants, Occupational↗

Aberrant expression and localization of the cytoskeleton-binding pp52 (LSP1) protein in hairy cell leukemia.

Non-retractable cell surface projections and cytoskeleton-mediated functional defects are distinguishing features of both hairy cell leukemia (HCL) and neutrophil actin dysfunction (NAD). These defects in NAD neutrophils are attributed to moderate over-expression of pp52 (LSP1), the F-actin-binding, leukocyte-specific phosphoprotein. Here we report that pp52 is similarly elevated in HCL patient PBMCs. Established HCL cell lines exhibited characteristic morphological features like those of fresh HCL cells and showed elevated pp52 levels. The excess pp52 in these HCL cell lines was selectively associated with the F-actin-rich cytoskeletal arrays in surface projections. Treatments producing radical changes in HCL cell shape also altered pp52 expression and intracellular distribution. Alpha interferon (IFNalpha, used to treat HCL) reduced pp52 levels, normalized intracellular pp52 distribution and reverted HCL cells to rounded B cell morphology. Phorbol ester stimulation rapidly generated hyper-phosphorylated pp52 isoforms which translocated from the cytoskeleton to the cytosol prior to the further elongation of surface spikes. This indicates a direct role for phosphorylation in controlling pp52 interactions with the cytoskeleton. Overall, these findings strongly suggest that elevated pp52 expression and/or selective cytoskeletal association contributes to the distinctive morphology of HCL cells.

Actins↗

Harris Galante cementless acetabular replacement in avascular necrosis.

We describe the results of 76 total arthroplasties of the hip for stage-III or stage-IV avascular necrosis of the femoral head. Harris Galante Porous cups were used in 63 patients between 1986 and 1994 and followed prospectively. We reviewed 70 hips with a follow-up of more than five years (mean 7.6). At the latest review the mean Harris Hip Score had improved from a preoperative value of 29 +/- 14.7 to 94 +/- 6.8. Radiologically, there was no evidence of acetabular migration. The rate of revision for the femoral component was 8.6%, three being undertaken for loosening and three to allow downsizing of the femoral head. The rate of revision for the acetabular component was 7.1% (five cups). At the time of revision none of the cups was clinically loose, and only required the liner to be changed. The rate of complications was low with no case of deep infection or dislocation, but nine of the 76 hips (11.8%) showed grade-III heterotopic ossification. Previous studies of patients undergoing cemented total hip arthroplasty for the treatment of advanced avascular necrosis have indicated a high incidence of loosening of the acetabular component. Our findings show good medium-term results using the Harris Galante Porous cup for acetabular reconstruction, together with a variety of cemented femoral components, for the treatment of this difficult problem.

Acetabulum↗

Efficacy of a preventive intervention for youths living with HIV.

OBJECTIVES: HIV transmission behaviors and health practices of HIV-infected youths were examined over a period of 15 months after they received a preventive intervention. METHODS: HIV-infected youths aged 13 to 24 years (n = 310; 27% African American, 37% Latino) were assigned by small cohort to (1) a 2-module ("Stay Healthy" and "Act Safe") intervention totaling 23 sessions or (2) a control condition. Among those in the intervention condition, 73% attended at least 1 session. RESULTS: Subsequent to the "Stay Healthy" module, number of positive lifestyle changes and active coping styles increased more often among females who attended the intervention condition than among those in the control condition. Social support coping also increased significantly among males and females attending the intervention condition compared with those attending the control condition. Following the "Act Safe" module, youths who attended the intervention condition reported 82% fewer unprotected sexual acts, 45% fewer sexual partners, 50% fewer HIV-negative sexual partners, and 31% less substance use, on a weighted index, than those in the control condition. CONCLUSIONS: Prevention programs can effectively reduce risk acts among HIV-infected youths. Alternative formats need to be identified for delivering interventions (e.g., telephone groups, individual sessions).

Adaptation, Psychological↗

An intervention for parents with AIDS and their adolescent children.

OBJECTIVES: This study evaluated an intervention designed to improve behavioral and mental health outcomes among adolescents and their parents with AIDS. METHODS: Parents with AIDS (n = 307) and their adolescent children (n = 412) were randomly assigned to an intensive intervention or a standard care control condition. Ninety-five percent of subjects were reassessed at least once annually over 2 years. RESULTS: Adolescents in the intensive intervention condition reported significantly lower levels of emotional distress, of multiple problem behaviors, of conduct problems, and of family-related stressors and higher levels of self-esteem than adolescents in the standard care condition. Parents with AIDS in the intervention condition also reported significantly lower levels of emotional distress and multiple problem behaviors. Coping style, levels of disclosure regarding serostatus, and formation of legal custody plans were similar across intervention conditions. CONCLUSIONS: Interventions can reduce the long-term impact of parents' HIV status on themselves and their children.

Acquired Immunodeficiency Syndrome↗

Coccidial contamination of raspberries: mock contamination with Eimeria acervulina as a model for decontamination treatment studies.

Numerous outbreaks have been reported since 1995 in the United States and Canada that were linked to the consumption of imported fresh raspberries contaminated with Cyclospora. Because Cyclospora has no laboratory animal hosts, Eimeria acervulina, a common chicken coccidium similar in characteristics to Cyclospora, was used as a surrogate to test decontamination treatments. Raspberries were mock contaminated with E. acervulina-sporulated oocysts in a water suspension, then exposed to washing, freezing, heat, or irradiation before they were fed to chicks. The presence of oocysts in the contaminated raspberries was confirmed either by duodenal lesions or oocysts in cecal contents 5 days postinoculation (PI) or in fecal contents 6 days PI, after 24 h of fecal collection. Washing of raspberries was generally not adequate in removing coccidial contamination, but freezing and heat treatment appeared effective. Gamma irradiation of E. acervulina-sporulated oocysts at a dose of 0.5 kGy was partially effective, but it was completely effective at 1.0 kGy and higher. We suggest that E. acervulina, for mock contamination of raspberries and subsequent decontamination treatments, is easy to handle, safe, and economical to study.

Animals↗

Life-threatening refeeding syndrome in a severely malnourished anorexia nervosa patient.

Overzealous refeeding in chronically malnourished anorexia nervosa patients may cause life-threatening complications. We describe a 14-year-old girl with anorexia nervosa who had a decrease in body weight from 45 kg to 25.5 kg over an 18-month period. She received 40 kcal.kg-1.d-1 carbohydrate-rich nutrition via enteral and parenteral routes. Her serum phosphate concentration dropped from a baseline of 1.39 mmol/L (4.3 mg/dL) to 0.19 mmol/L (0.6 mg/dL) on Day 4 of refeeding. Concurrent with the development of hypophosphatemia, she became drowsy and developed generalized muscle weakness, impaired myocardial contractility, thrombocytopenia, and gastrointestinal bleeding. Fluid overload with pulmonary edema complicated her recovery from these adverse events. After intravenous phosphate supplementation and fluid restriction, the symptoms of refeeding syndrome gradually resolved within 2 weeks. In chronically malnourished anorexia nervosa patients, nutritional support should be instituted gradually to avoid rapid electrolyte shifts and fluid overload. Serum phosphate concentrations, fluid status, and blood cell counts should be closely monitored.

Adolescent↗

Periodontal repair in dogs: effect of transforming growth factor-beta 1 on alveolar bone and cementum regeneration.

BACKGROUND: Transforming growth factor-beta (TGF-beta) represents a family of growth-modulating proteins with fundamental roles in connective tissue and bone development. The objective of this study was to evaluate the potential for regeneration of alveolar bone and cementum following surgical implantation of recombinant human TGF-beta 1 (rhTGF-beta 1). METHOD: Bilateral, critical size, supra-alveolar periodontal defects in 5 beagle dogs were surgically implanted with rhTGF-beta 1 in a calcium carbonate carrier (CaCO3) or with carrier alone. The animals were euthanized at 4 weeks postsurgery and block-biopsies of the defects were processed for histologic and histometric analysis. RESULTS: Surgical implantation of rhTGF-beta 1 resulted in minimal, if any, stimulation of alveolar bone or cementum regeneration. Linear bone and cementum regeneration in rhTGF-beta 1-treated defects was 1.2+/-0.6 and 0.01+0.01 mm, respectively. Corresponding values for the controls were 1.0+/-0.6 and 0.01+/-0.03 mm. CONCLUSIONS: The results suggest that, under the conditions (dose, carrier, defect type) evaluated here, treatment of periodontal defects in beagle dogs with rhTGF-beta 1 may be of limited clinical benefit.

Alveolar Process↗

Cementless acetabular replacement in the young. A 5- to 10-year prospective study.

This article presents a prospective clinical and radiologic review of 55 total hip replacements in 50 patients in which the cementless Harris-Galante porous-coated acetabular component was used. All patients were 50 years of age or younger. The cups were inserted by 15 different surgeons. The minimum followup was 5 years, with a mean of 7 years. No acetabular component has been revised for loosening, and none have migrated. Three (5.5%) cups have progressive bone-component radiolucent lines, two (3.6%) of which are complete. Six (10.9%) acetabular liners have been replaced for excessive polyethylene wear, and an additional four (7.3%) show sufficient wear to produce obvious radiographic eccentricity of the femoral head. All of the revised liners had 32-mm femoral heads and an initial polyethylene thickness of less than 6 mm. Although the results reflect excellent fixation of this component in the medium term, the incidence of exchange of the polyethylene liner for excessive wear is unacceptably high. The reduction in polyethylene thickness associated with the use of a metal-backed component and a 32-mm articulation was one of the factors contributing to the accelerated wear patterns seen in this series.

Acetabulum↗

Periodontal repair in dogs: histologic observations of guided tissue regeneration with a prostaglandin E1 analog/methacrylate composite.

This report describes observations of healing following guided tissue regeneration (GTR) including surgical implantation of the prostaglandin E1 analog misoprostol with calcium-layered methacrylate particles. Critical size, supra-alveolar periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in 4 beagle dogs. Wound management included soaking with a 24 microg/ml misoprostol solution and implantation of the misoprostol/methacrylate composite. One jaw quadrant per animal was prepared for GTR using expanded polytetrafluoroethylene membranes. The gingival flaps were coronally advanced and sutured to submerge the teeth. The tissues covering the surgical sites daily received topical misoprostol in an oral adhesive over the 4-week healing interval. Upon euthanasia, tissue blocks were prepared for histometric analysis of regeneration of alveolar bone and cementum, root resorption and ankylosis. The defect area underneath the membrane and the density of methacrylate particles were recorded for the GTR defects. The methacrylate particles appeared encapsulated in a dense connective tissue without signs of an inflammatory reaction, some in contact to newly formed bone. Alveolar bone regeneration height averaged (+/-SD) 1.2+/-1.0 and 1.0+/-0.6 mm for GTR and non-GTR defects, respectively. Corresponding values for bone regeneration area were 1.3+/-1.0 and 0.7+/-0.5 mm2. Cementum regeneration was confined to the apical aspect of the defects. Small areas of root resorption and ankylosis were observed for all teeth. Bone regeneration area correlated positively to the defect area and negatively to the density of methacrylate particles in the GTR defects. The histologic observations suggest that the methacrylate composite has marginal potential to promote bone and cementum regeneration under provisions for GTR.

Alveolar Bone Loss↗