Biomedical subjects

Michael Wiseman

Publications and source records attributed to Michael Wiseman.

7 recordsLinked to original sources

PubMed2006

Detrimental effect of oral contraceptives on parameters of bone mass and geometry in a cohort of 248 young women.

The aim of this cross-sectional analysis was to examine the skeletal effects of low-dose monophasic oral contraceptive (OC) use in a cohort of 248 young Caucasian women aged 18-24 years. Areal bone mineral density (BMD) of the femoral neck and lumbar spine was evaluated by dual-energy X-ray absorptiometry. Volumetric BMD, bone mineral content (BMC), and bone geometry were assessed in the tibia by peripheral quantitative computed tomography (pQCT). The women were allocated into ever or never OC users, and also into 5 different OC groups according to duration and time of initiation of OC use. Women with >2 years of OC use and OC initiation within 3 years after menarche were characterized by 10% lower femoral neck areal BMD (P<0.001), 5% lower spine areal BMD (not significant, P=0.101), 7% lower distal tibial total BMC (P<0.05), and 6% lower total BMC at the tibial shaft (P<0.05) relative to never users. In addition, women who had ever used OCs had lower bone mass at the femoral neck and tibial shaft, despite similar age, height, weight, BMI, hours of exercise, and calcium intake compared with never users. At the tibial shaft, OC users showed reduced total cross-sectional area, and increased cortical BMD. In conclusion, our data suggest that OC use is associated with a detrimental effect on bone mass in young women, and provide further insight into the pathophysiological mechanisms involved.

Absorptiometry, Photon↗

PubMed2006

Comparison of the skeletal effects of the progestogens desogestrel and levonorgestrel in oral contraceptive preparations in young women: controlled, open, partly randomized investigation over 13 cycles.

AIM: This 12-month study was conducted to evaluate the skeletal effects of two monophasic oral contraceptives containing 20 mug of ethinylestradiol and 100 mug of levonorgestrel (LEVO) or 150 mug of desogestrel (DESO). METHODS: Fifty-two women (18-24 years) were randomized into the DESO group or the LEVO group; 36 women served as controls. The areal bone mineral density (aBMD) of the femoral neck and the lumbar spine was evaluated by DXA, and parameters of bone geometry and volumetric bone mineral density (vBMD) were assessed by peripheral quantitative computed tomography at the distal radius and the tibia. RESULTS: The LEVO group did not lose vertebral aBMD, whereas women in the DESO group lost 1.5%. At the distal radius and the tibia (shank level, 14%), LEVO induced an increase in total cross-sectional area, indicating increased periosteal bone formation. Radial trabecular vBMD declined by 1.4+/-1.8% in the DESO group, while it remained unchanged in the LEVO group. CONCLUSION: Our study suggests that the skeletal effects of OC preparations may be influenced by progestogenic components in young women.

Absorptiometry, Photon↗

PubMed2006

Do autologous mesenchymal stem cells augment bone growth and contact to massive bone tumor implants?

This study investigated the hypothesis that spraying autologous mesenchymal stem cells (MSCs) onto grooved hydroxyapatite (HA) coated collars of segmental bone tumor implants would increase bone growth and contact to the implant surface in an ovine model. Autologous MSCs were isolated from bone marrow, grown in culture and during surgery implants in group 1 were sprayed with MSCs, suspended within fibrin glue. Implants in group 2 received no MSC therapy and acted as control. Implants remained in vivo for 6 months. New bone area and contact to the implant was quantified on radiographs and histologically. Radiographic analysis demonstrated greater total bone area in the MSC treated group in both ML (MSC = 79.738 mm2 +/- 22.964; control = 30.135 mm2 +/- 6.717) (p = 0.018) and AP (MSC = 90.338 +/- 19.361 mm2; control = 57.384 +/- 9.035 mm2 (p = 0.074) radiographs at 6 months. Results demonstrated significantly increased bone growth in the MSC group at 2 (p = 0.03) and 3 months (p < 0.05). Histological analysis demonstrated significantly greater bone area adjacent to the collars in the treated group (53.994 +/- 10.641 mm2) when compared with the control group 21.069 +/- 7.339 mm2 (p = 0.020). Increased bone contact in the MSC group (19.833 +/- 8.729 %) was observed when compared with controls (8.667 +/- 8.667%). This novel application of spraying MSCs onto the implant surface has significant implications for the future of successful implant fixation.

Animals↗

PubMed2006

The treatment of oral problems in the palliative patient.

Palliative care patients require special dental attention, ranging from operative and preventive care to support for emotional needs. The dentist"s role in palliative care is to improve quality of life of the patient. This paper describes some common problems encountered in palliative care dentistry for adults with terminal cancer and the appropriate treatment of these problems.

Antifungal Agents↗

PubMed2004

Age at first oral contraceptive use as a major determinant of vertebral bone mass in female endurance athletes.

It was the aim of this retrospective analysis to examine the influence of low-dose monophasic oral contraceptives (OCs) on bone mineral density (BMD) of the femoral neck and of the spine in young female endurance athletes. Data on training intensity, dietary intake, menarche, menstrual cycle disorders, years of OC use, and age at first OC use were determined by a self-report questionnaire. Only athletes performing regular endurance exercise for more than 3 years with more than 3 h of exercise per week were included in this study and underwent a clinical assessment including measurement of weight, height, spine, and hip BMD by dual-energy X-ray absorptiometry, and collection of a blood sample. The data from 75 regularly exercising endurance athletes aged 18-35 years (26.5 +/- 4.8 years) were initially included in this analysis. Six athletes were later excluded due to oligo-/amenorrhea. Subjects were allocated into the OC group when they reported OC use for more than 3 years in women younger than 22 years of age, or when they reported OC use for more than 50% of the time after menarche in women aged 22-35 years. There were no differences in age, weight, height, body mass index (BMI), body fat, menarche, training intensity, age at start of training, or any serum parameters between OC users (n = 31) and control subjects (n = 38). However, OC users had 7.9% lower spine BMD and 8.8% lower proximal femur BMD (P < 0.01 for both sites). When the relationship between BMD of the spine and OC use was further analyzed by a stepwise model of multiple regression analysis using OC years, age at OC initiation, BMI, and menarche as independent variables, age at first OC use was found to be the best predictor of vertebral BMD, while the only significant predictor of femoral neck BMD was BMI. We conclude that OC use is associated with decreased BMD of the spine and the femoral neck in female endurance athletes, and that early age at initiation of OC use may be an important risk factor for low peak bone mass in young women.

Adolescent↗

PubMed2003

Explaining variation in the effects of welfare-to-work programs.

Evaluations of government-funded training programs often combine results from similar operations in multiple sites. Findings inevitably vary. It is common to relate site-to-site variations in outcomes to variations in program design, participant characteristics, and the local environment. Frequently, such connections are constructed in a narrative synthesis of multisite results. This article uses findings from the evaluations of California's Greater Avenues for Independence (GAIN) program and the National Evaluation of Welfare-to-Work Strategies (NEWWS) to illustrate why it is important to question the legitimacy of such syntheses. The discussion is carried out using a simple multilevel evaluation model that incorporates models of both individual outcomes within sites and variation in program effects across sites. The results indicate that tempting generalizations about GAIN and NEWWS effects are statistically unjustified but that significant progress might be made in identifying the determinants of program effects in future demonstrations with some changes in evaluation strategy.

Employment↗

PubMed2002

Anti-inflammatory effects of a low arachidonic acid diet and fish oil in patients with rheumatoid arthritis.

BACKGROUND: Patients with rheumatoid arthritis (RA) improve on a vegetarian diet or supplementation with fish oil. We investigated the effects of both dietary measures, alone and in combination, on inflammation, fatty acid composition of erythrocyte lipids, eicosanoids, and cytokine biosynthesis in patients with RA. METHODS: Sixty-eight patients with definitive RA were matched into two groups of 34 subjects each. One group was observed for 8 months on a normal western diet (WD) and the other on an anti-inflammatory diet (AID) providing an arachidonic acid intake of less than 90 mg/day. Patients in both groups were allocated to receive placebo or fish oil capsules (30 mg/kg body weight) for 3 months in a double-blind crossover study with a 2-month washout period between treatments. Clinical examination and routine laboratory findings were evaluated every month, and erythrocyte fatty acids, eicosanoids, and cytokines were evaluated before and after each 3-month experimental period. RESULTS: Sixty patients completed the study. In AID patients, but not in WD patients, the numbers of tender and swollen joints decreased by 14% during placebo treatment. In AID patients, as compared to WD patients, fish oil led to a significant reduction in the numbers of tender (28% vs 11%) and swollen (34% vs 22%) joints (P<0.01). Compared to baseline levels, higher enrichment of eicosapentaenoic acid in erythrocyte lipids (244% vs 217%) and lower formation of leukotriene B(4) (34% vs 8%, P>0.01), 11-dehydro-thromboxane B(2) (15% vs 10%, P<0.05), and prostaglandin metabolites (21% vs 16%, P<0.003) were found in AID patients, especially when fish oil was given during months 6-8 of the experiment. CONCLUSION: A diet low in arachidonic acid ameliorates clinical signs of inflammation in patients with RA and augments the beneficial effect of fish oil supplementation.

Arachidonic Acid↗