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Biomedical subjects

L Rich

Publications and source records attributed to L Rich.

15 recordsLinked to original sources

Endothelium-dependent and independent vasodilation studies at normoglycaemia in type I diabetes mellitus with and without microalbuminuria.

AIMS/HYPOTHESIS: We examined whether endothelial function is impaired in patients with Type I (insulin-dependent) diabetes mellitus under conditions of near-normoglycaemia compared with age-matched healthy control subjects. Our aim was to determine whether microalbuminuria is associated with endothelial dysfunction in Type I diabetes. METHODS: Endothelial function, measured as post-ischaemic flow-mediated dilatation of the brachial artery using ultrasound, was compared among 17 microalbuminuric and 17 normoalbuminuric diabetic patients, and 17 control subjects. Glyceryl trinitrate-mediated dilatation of the brachial artery was used to measure endothelium-independent function. All diabetic patients were studied at near-normoglycaemia, using insulin and 5 % dextrose infusions to maintain blood glucose between 3.5 and 8.0 mmol/l. RESULTS: Flow-mediated dilatation was significantly lower in microalbuminuric diabetic patients (3.2 +/- 0.3%) compared with normoalbuminuric diabetic patients (5.4 +/- 0.6%) and control subjects (7.9 +/- 0.6%, p < 0.001). Normoalbuminuric diabetic patients also had significantly lower flow-mediated dilatation than control subjects (p = 0.01). Glyceryl trinitrate mediated dilatation was significantly lower in the microalbuminuric patients compared with the control subjects (11.9 +/- 1.1% vs 20.0 +/- 1.2%, p = 0.001). Albumin excretion rate and glycated haemoglobin showed a significant negative independent correlation with flow-mediated dilatation (both p < 0.05). CONCLUSION/INTERPRETATION: Type I diabetic patients show endothelial dysfunction at near-normoglycaemia compared with the control subjects, and this abnormality is more marked in diabetic patients with microalbuminuria. Endothelial dysfunction in Type I diabetes is related to the albumin excretion rate and glycaemic control. The presence of endothelial dysfunction in normoalbuminuric diabetic patients suggests it could precede microalbuminuria as an early risk marker for cardiovascular disease.

Adolescent↗

Corneal ulcers in patients with Apert syndrome.

Morbidity from corneal ulcers is often severe in patients with Apert syndrome. These patients are at an increased risk of developing corneal ulcers because of the compromised corneal environment secondary to exophthalmos. During the past 6 years, three of five patients treated for Apert syndrome at our hospital have developed corneal ulcers. We present a case series discussing each patient, reasons for the development of ulceration, treatment, and outcomes. Morbidities in our group of patients included decreased visual acuity, opacified corneas, amblyopia, and blindness. Treatment is often difficult and complex. Therefore, an ophthalmologist should be an active team member in treating Apert patients.

Acrocephalosyndactylia↗

Maintenance of safer sexual behaviours: evaluation of a theory-based intervention for HIV seropositive men with haemophilia and their female partners.

A theory-based HIV risk-reduction intervention was developed for HIV-positive men with haemophilia and their HIV-negative female romantic partners. The intervention was based on Prochaska and DiClemente's Transtheoretical Model which describes behaviour change as an incremental, stage-based process. The intervention targeted both communication about safer sex and safer sex behaviours (consistent condom use or abstinence from vaginal intercourse). A total of 255 males and 158 females from six funded haemophilia treatment centres or patient organizations (and 27 associated subsites) participated in the study. Baseline and follow-up (15 months after baseline) measures were administered to assess safer sexual behaviours, communication about safer sex and condom self-efficacy. A quasi-experimental, repeated measures design was utilized to compare two naturally occurring groups; those who received the full intervention package and those who received incomplete or no intervention components. Significant intervention effects for safer sex behaviours, communication about safer sex and condom self-efficacy were identified for the male participants, with those receiving the full intervention package demonstrating better outcomes at follow-up. Women who received the full intervention package were more likely to report the use of a condom by their male partner during the last act of vaginal intercourse.

Adult↗

Smoking behaviors of women whose children attend an urban pediatric primary care clinic.

OBJECTIVE: To characterize smoking behaviors of caregivers whose children attend a large urban pediatric primary care center. DESIGN: Descriptive survey. Women (n = 479) classified as smokers completed a questionnaire including demographics, smoking habits, measures of addiction, social reinforcers for smoking, attitudes and knowledge, other health and safety habits, and the pediatrician's role in smoking cessation counseling. RESULTS: Of 1421 women surveyed, 36.6% (517) were classified as daily smokers. Four hundred and seventy-nine (93%) were enrolled in the study. Thirty-eight (7%) refused or were ineligible. Smokers differed significantly from non-smokers, with smokers more likely to have lower incomes (p<.03), lower educational attainment (p<.001), and were more likely to be white than non-smokers (p<.001). The average smoker smoked 14 cigarettes per day for 10 years. Half of the subjects had not considered quitting smoking in the near future. The majority of subjects (66%) lived with at least one other smoker, and reported that more than half of their friends smoked. Most (79%) participants agreed that pediatricians should give smoking cessation advice to parents of their patients. However, only 19% recalled being counseled to quit, and 55% recalled their child's doctor discussing the danger of environmental tobacco smoke. CONCLUSION: The pediatric visit is an excellent opportunity for identifying women who smoke. Efforts to assist women with smoking cessation in similar settings will need to take into account their poverty and the high degree of social support for their continued smoking.

Adult↗

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors: oxime ether analogs of pravastatin.

Pravastatin, a potent anti-hypercholesteremic drug, has been developed by Bristol-Myers Squibb for treatment of hypercholesterolemia and other related diseases. Several structurally related compounds (SQ 31,554, SQ 31,879, SQ 31,947, SQ 32,391, SQ 32,770, SQ 32,390 and SQ 32,469) modified at the 3-position of the hexahydronaphthalene ring system of pravastatin were prepared in the course of developing the basic reagents for a radioimmunoassay of the parent drug. The biological activity of these analogs was comparable to pravastatin itself. Indeed, one member of this series was found to be several times more potent than pravastatin.

Animals↗

Detection of mRNA for the cytokines, interleukin-1 alpha and interleukin-8, in corneas from patients with pseudophakic bullous keratopathy.

PURPOSE: Cytokines have been implicated in corneal inflammatory diseases. The authors sought to determine if corneal diseases with different patterns of inflammation are accompanied by characteristic patterns of cytokine expression. METHODS: The authors used reverse transcription-polymerase chain reaction to detect mRNA for 12 specific cytokines from patients with Fuch's dystrophy (n = 7), pseudophakic bullous keratopathy (n = 12), or normal corneas (n = 4). RESULTS: Using Wilcoxon rank sum analysis, mRNA for interleukin (IL)-1 alpha or IL-8 was significantly more abundant in corneas from patients with pseudophakic bullous keratopathy relative to either comparison group. mRNA for the T-cell marker, CD4, and for T-cell derived cytokines, IL-2, IL-4, and interferon gamma, could not be detected in any corneal sample. Message for IL-1 receptor antagonist and transforming growth factor-beta 1 or -beta 2 was readily detectable in most corneas regardless of diagnosis. CONCLUSION: The findings indicate that the pattern of cytokine mRNA expression reflects differences in the pathogenesis of these corneal diseases.

Aged↗

Hepatitis C is a poor prognostic indicator in black kidney transplant recipients.

BACKGROUND: The significance of hepatitis C in kidney transplant recipients is unclear. The prevalence of antibodies to hepatitis C among candidates for transplantation is up to 50% in some centers. METHODS: We screened 640 frozen serum samples obtained pretransplantation from all kidney recipients at the Medical College of Wisconsin between January 1979 and March 1990 for antibody to hepatitis C using the second generation immunoassay. Charts were reviewed from all hepatitis C antibody-positive (anti-HCV+) patients and 256 randomly chosen hepatitis C antibody negative (anti-HCV-) controls. Actuarial patient and graft survival in these two groups were determined. RESULTS: The prevalence of anti-HCV was 8.3%. Blacks and i.v. drug users were disproportionately represented in the anti-HCV+ group. Of the anti-HCV+ patients, 18.9% developed chronic hepatitis independent of race. Black anti-HCV+ patients had a 5-year graft survival of 28 +/- 11% compared to 67 +/- 7% in black anti-HCV- patients (P = 0.003). Black anti-HCV-, white anti-HCV-, and white anti-HCV+ patients all had similar graft survival. Anti-HCV was not a poor prognostic indicator for overall patient survival or the development of aplastic anemia and malignancies including hepatocellular carcinoma. CONCLUSIONS: Anti-HCV is a significant risk factor for reduced kidney graft survival in blacks apart from i.v. drug abuse. Black anti-HCV- patients had graft survival similar to white transplant recipients, indicating that anti-HCV may be one marker for the poorer graft survival in blacks that has been observed in most transplant programs. Anti-HCV in kidney transplant recipients increases the risk for the development of chronic hepatitis post-transplant.

Adult↗

N-glycolylneuraminic acid and N-acetylneuraminic acid define feline blood group A and B antigens.

Blood group incompatibility causes transfusion reactions and neonatal isoerythrolysis in cats. We investigated the molecular nature of the blood group antigens from cats that had blood type A, B, and AB erythrocytes. Naturally occurring anti-type B antibodies, Triticum vulgaris lectin, monoclonal antibody (MoAb) 32-27, and MoAb R-24 were used in agglutination tests, Western blots, and thin-layer chromatography (TLC) enzyme immunostaining. Type A erythrocytes had NeuGc-NeuGc-Galactose-Glucose-Ceramide ([NeuGc]2GD3) where NeuGc represents N-glycolylneuraminic acid, and NeuAc-NeuGc-GD3, where NeuAc represents N-acetylneuraminic acid, and may have [NeuGc]2 disialylparagloboside and NeuAc-NeuGc-disialylparagloboside. Type B erythrocytes only had [NeuAc]2GD3. Type AB erythrocytes had [NeuGc]2GD3, NeuAc-NeuGc-GD3, and [NeuAc]2GD3. Blood group antigens were also found on a 50-Kd membrane protein. We conclude that type B erythrocytes are characterized by [NeuAc]2GD3 as the only form of this ganglioside and the presence of NeuAc on a 50-Kd membrane protein. NeuGc is the major determinant of the A antigen; specifically, [NeuGc]2GD3 is the major glycolipid form. The A antigen is also present on a 50-Kd membrane protein.

ABO Blood-Group System↗

Obesity in black adolescent girls: a controlled clinical trial of treatment by diet, behavior modification, and parental support.

Recent findings indicate that nearly 50% of black American women are obese and that adolescence is a critical period for the development of their obesity. This study investigated the efficacy of a behavioral weight control program in 36 black female adolescents with a mean age of 14.0 years, weight of 95.0 kg, and height of 163.2 cm. All subjects participated in the same 16-week program but had different levels of parent participation: (1) child alone with no parent participation; (2) mother and child treated in the same session; and (3) mother and child treated in separate but concurrent session. At the end of the 16-week program, children in the three conditions lost 1.6, 3.7, and 3.1 kg, respectively. Differences among conditions were not statistically significant; however, a secondary analysis revealed that the greater the number of sessions attended by mothers, the greater their daughters' weight losses. Weight reduction was associated with significant improvements in body composition, serum total cholesterol concentrations, and psychological status. Results are discussed in terms of the need to improve the maintenance of weight loss in adolescents and to explore possible differences between black and white females in their preferred body types.

Adolescent↗

Diurnal variation in vision after radial keratotomy.

We tested eight patients who had undergone radial keratotomy with regard to refraction, keratometry, corneal thickness, and intraocular pressure one to two weeks after surgery. Patients were examined immediately after eye-lid opening at 7:30 A.M. and again at 4:00 P.M. The contralateral eye was used as a control. The treated eye was 1.48 +/- 0.24 diopters (mean +/- S.E.M.) more hyperopic at the morning examination compared to the afternoon visit, whereas the control eye had an insignificant shift (0.16 +/- 0.06 diopters). The treated eye was significantly flatter (1.37 +/- 0.19 diopters) in the morning than in the afternoon when compared to the control eyes, which were only 0.11 +/- 0.09 diopter flatter. The intraocular pressure changed insignificantly in both the treated and control eyes (-0.5 +/- 0.53 mm Hg and -0.5 +/- 0.84 mm Hg, respectively). The mean morning corneal thickness was significantly greater (5.7%) than the afternoon thickness when compared to the controls (1.7% morning increase in thickness). These data suggest that diurnal variation in corneal thickness after radial keratotomy plays a role in diurnal variation of vision in the early postoperative period.

Adult↗

Stereo-discrimination between diplopic images in clinically normal observers.

When retinal disparity exceeds the limits for fusion, the resulting images are perceived as diplopic. In a stereo test that allowed comparison of crossed and uncrossed disparity sensitivities, 74% of the subjects perceived convergent disparities more readily than divergent disparities. This asymmetric sensitivity to disparity did not appear to be related to measurements of phoria, vergence amplitudes, or clinical measurements of stereo acuity.

Depth Perception↗

Inhibition of cis-diamminedichloroplatinum secretion by the human kidney with probenecid.

The renal handling of cis-diamminedichloroplatinum (CP) was investigated by measuring the renal clearance of creatinine, inulin, and free platinum in ten cancer patients. Free platinum clearances exceeded the glomerular filtration rate in all time periods. For example, at 1 to 2 hr, the mean clearance of free platinum was 224 +/- 32 (S.E.) ml/min compared to a mean creatinine clearance of 94 +/- 15 ml/min or a mean inulin clearance of 94 +/- 17 ml/min (p less than 0.01), indicating secretion of CP or a metabolite. Seven additional cancer patients were treated with probenecid prior to CP. Fractional platinum clearances, calculated as a ratio of free platinum clearance to creatinine clearance, were reduced significantly in the probenecid-treated group (158 +/- 17%) compared to controls (270 +/- 57%) (p less than 0.03). Fractional platinum clearances, calculated as a ratio of free platinum clearance to inulin clearance, were also significantly reduced in the treated group (154 +/- 14%) compared to controls (271 +/- 47%) (p = 0.04). These results suggest that cisplatin is secreted by the human kidney, and this can be inhibited by probenecid. Such maneuvers may be helpful in improving the therapeutic index of this important chemotherapeutic agent.

Cisplatin↗

Effects of growth factors on corneal wound healing.

Rabbits received nonpenetrating central corneal knife wounds. Immediately after wounding, a single 2.5 or 5.0 micron dose of mesodermal growth factor (MGF) was applied topically to the wound. Controls were treated with saline. Electron microscopic studies compared the healing responses of the control and treated animals over a 7-day period. MGF was a potent nitrogen for keratocytes in rabbit corneas. The single dose enhanced fibroblast proliferation and metabolic activity. Control wounds were not healed after 7 days, whereas those of treated animals showed complete healing.

Animals↗

Lacrimal system dacryoliths.

Seventy consecutive patients undergoing dacryocystorhinostomy for chronic dacryocystitis or dacryostenosis were analyzed. Lacrimal sac stones were found in 11 patients for an incidence of 16%. All stones were studied histopathologically and six of these stones demonstrated morphological characteristics compatible with fungus. Two stones were cultured and one of these grew aerobes with the other growing fungi only. A series of nine patients with canalicular dacryoliths was analyzed. All patients were studied clinically and bacteriologically. No fungus was found on any of these cases. Aerobic cultures were positive in two patients. All patients with canalicular stones grew anaerobes with arachnia propionica and fusobacterium species predominating. The treatment for both problems is recognition and removal of the stones.

Adult↗