Suppression of Parathyroid Hormone and Bone Resorption by Calcium Carbonate and Calcium Citrate in Postmenopausal Women

This study was conducted to compare the suppressive effects of calcium carbonate and calcium citrate on bone resorption in early postmenopause. Calcium citrate is thought to be better absorbed. We therefore tested the hypothesis that calcium as citrate is more effective than calcium as carbonate in suppressing parathyroid hormone (PTH) and C-terminal telopeptide. Twenty-five healthy postmenopausal women were recruited in this double blind crossover study. The subjects were randomly allocated to receive either 1,000 mg of elemental calcium as carbonate or 500 mg of calcium as citrate. They were given the alternate calcium dose 1 week later. Serum measurements of total and ionized calcium, phosphate, PTH, and CrossLaps were repeated 12 hours after each dose. Analysis of variance found no significant difference between measures for the two salts. Tests for equivalence indicated that 500 mg of calcium citrate may be superior to 1,000 mg of calcium carbonate in raising serum total and ionized calcium (P = 0.04 and 0.05, respectively). For all parameters measured, 500 mg of calcium citrate was at least as beneficial as 1,000 mg of calcium carbonate. Calcium citrate is at least as effective as calcium carbonate in suppressing PTH and C-terminal telopeptide cross-links, at half the dose. This may be because calcium as citrate is better absorbed than calcium as carbonate. If calcium citrate can be used in lower doses, it may be better tolerated than calcium carbonate.     

Pyridoxamine reduces methylglyoxal and markers of glycation and endothelial dysfunction,but does not improve insulin sensitivity or vascular function in abdominally obese individuals: A randomized double-blind placebo-controlled trial

Aim

To investigate the effects of pyridoxamine (PM), a B6 vitamer and dicarbonyl scavenger, on glycation and a large panel of metabolic and vascular measurements in a randomized double-blind placebo-controlled trial in abdominally obese individuals.

Materials and methods

Individuals (54% female; mean age 50 years; mean body mass index 32 kg/m²) were randomized to an 8-week intervention with either placebo (n = 36), 25 mg PM (n = 36) or 200 mg PM (n = 36). We assessed insulin sensitivity, β-cell function, insulin-mediated microvascular recruitment, skin microvascular function, flow-mediated dilation, and plasma inflammation and endothelial function markers. PM metabolites, dicarbonyls and advanced glycation endproducts (AGEs) were measured using ultra-performance liquid chromatography tandem mass spectrometry. Treatment effects were evaluated by one-way ANCOVA.

Results

In the high PM dose group, we found a reduction of plasma methylglyoxal (MGO) and protein-bound Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1), as compared to placebo. We found a reduction of the endothelial dysfunction marker soluble vascular cell adhesion molecule-1 (sVCAM-1) in the low and high PM dose group and of soluble intercellular adhesion molecule-1 (sICAM-1) in the high PM dose, as compared to placebo. We found no treatment effects on insulin sensitivity, vascular function or other functional outcome measurements.

Conclusions

This study shows that PM is metabolically active and reduces MGO, AGEs, sVCAM-1 and sICAM-1, but does not affect insulin sensitivity and vascular function in abdominally obese individuals. The reduction in adhesion markers is promising because these are important in the pathogenesis of endothelial damage and atherosclerosis.     

Human isolates of <Emphasis Type="Italic">Bartonella tamiae</Emphasis>induce pathology in experimentally inoculated immunocompetent mice

Background  

Bartonella tamiae, a newly described bacterial species, was isolated from the blood of three hospitalized patients in Thailand. These patients presented with headache, myalgia, anemia, and mild liver function abnormalities. Since B. tamiae was presumed to be the cause of their illness, these isolates were inoculated into immunocompetent mice to determine their relative pathogenicity in inducing manifestations of disease and pathology similar to that observed in humans.     

Association between sitting and occupational LBP

Low back pain (LBP) has been identified as one of the most costly disorders among the worldwide working population. Sitting has been associated with risk of developing LBP. The purpose of this literature review is to assemble and describe evidence of research on the association between sitting and the presence of LBP. The systematic literature review was restricted to those occupations that require sitting for more than half of working time and where workers have physical co-exposure factors such as whole body vibration (WBV) and/or awkward postures. Twenty-five studies were carefully selected and critically reviewed, and a model was developed to describe the relationships between these factors. Sitting alone was not associated with the risk of developing LBP. However, when the co-exposure factors of WBV and awkward postures were added to the analysis, the risk of LBP increased fourfold. The occupational group that showed the strongest association with LBP was Helicopter Pilots (OR=9.0, 90% CI 4.9–16.4). For all studied occupations, the odds ratio (OR) increased when WBV and/or awkward postures were analyzed as co-exposure factors. WBV while sitting was also independently associated with non-specific LBP and sciatica. Vibration dose, as well as vibration magnitude and duration of exposure, were associated with LBP in all occupations. Exposure duration was associated with LBP to a greater extent than vibration magnitude. However, for the presence of sciatica, this difference was not found. Awkward posture was also independently associated with the presence of LBP and/or sciatica. The risk effect of prolonged sitting increased significantly when the factors of WBV and awkward postures were combined. Sitting by itself does not increase the risk of LBP. However, sitting for more than half a workday, in combination with WBV and/or awkward postures, does increase the likelihood of having LBP and/or sciatica, and it is the combination of those risk factors, which leads to the greatest increase in LBP.     

Preparing the young to look after the old.

In Malaysia the steady rise in the proportion of people aged 60 or more, and an awareness of their complex psychosocial, economic and health care needs, have led medical faculties to introduce geriatrics as an essential subject in their curricula. The efforts made in this field by the School of Medical Sciences of the Universiti Sains Malaysia are outlined in the present article.     

小红参的化学成分研究

小红参的化学成分研究徐晓莹，周金云，方起程（中国医学科学院中国协和医科大学药物研究所，北京１０００５０）小红参（Ｒｕｂｉａｙｕｎｎａｎｅｎｓｉｓ（Ｆｒａｎｃｈ）Ｄｉｅｌｓ）是茜草科茜草属植物云南茜草的根（１）。民间根据小红参有温经通络、活血祛风、软坚...     

Database analysis of injury patterns in an institution for developmental disabilities

This paper reports the results of a statistical analysis of injuries to the clients and the employees of a state facility for people with developmental disabilities, as recorded in the respective databases of the institution. The goal of the analysis was to identify the characteristics and patterns of injuries in order to identify priorities for technological intervention. Databases for 2000 client injuries and for 900 direct care staff injuries between 1988 and 1991 were analyzed retrospectively. Most of the injuries were sustained by the direct care staff and involved their backs. The injuries occurred in the institution's bedrooms (approximately 25%) and bathrooms (approximately 15%) and took place mainly during the early morning (approximately 30%) and evening rush (20%). The time of day and location of the injuries of clients coincided with those of the injuries of employees. These findings direct the focus of technological based interventions.