Does dietary calcium have a protective effect on bone fractures in women? A meta-analysis of observational studies

It is generally accepted that supplemental Ca and/or vitamin D is effective in reducing the incidence of bone fractures; this is supported by numerous randomised controlled trials and meta-analyses. However, a question that has received much less attention is whether dietary Ca, i.e. Ca in physiological doses in normal food intake, also affects bone fracture risk. The present study aims to review the effect of dietary Ca on bone fractures at the hip, spine and radius in women >35 years old, and to compare these results with previous meta-analyses. MEDLINE (1966-1999) and reference lists in papers were searched for observational dietary Ca studies. Data were extracted in duplicate and separately. Heterogeneity and publication bias were tested. Observational studies failed to show any association between dietary Ca intake and risk of hip fracture (risk ratio 1.01, 95 % CI 0.96, 1.07 for each increment of 300 mg dietary Ca intake/d). There is a suggestion that either extremely low Ca intake may increase fracture risk, or that East Asian women may respond differently to increasing Ca intake.     

The effect of Nestorone on gonadotropic cells in pituitary of rats

The implant containing Nestorone is a promising long-acting contraceptive especially suitable for lactating women. In this study, two experiments were designed to observe the effect of Nestorone on the gonadotropic cells in pituitary of rats for analyzing its antiovulation mechanism. In the first experiment, the ED₅₀ of Nestorone on inhibiting ovulation was found to be 1.32 mg/kg. The serum luteinizing hormone (LH) levels were significantly lower 60 h after being treated with Nestorone at 8:30–9:00 a.m. on Day 2 (D2) of estrus. Image analysis showed that the average size of the LH cells in groups treated with Nestorone at 2 or 4 mg/kg was larger than that of the control. In the group treated with 4 mg/kg, most of gonadotropic cells were regular round in shape. And, abundant granules in cytoplasm were found in those cells, which indicated that the LH stored in cells was not released. In the second experiment, the rats were treated with Nestorone at 5 mg/kg at 11:30–12:00 a.m. on D2 of estrus. The normal or higher expression of LHβ mRNA in pituitary suggested that the synthesis of LH was not inhibited by the treatment with Nestorone. The expression of PR mRNA in pituitary was significantly lower than that of the control at 33 h after treatment. This might be a direct effect of Nestorone, since there were no differences in the serum E₂ and P₄ levels between the treated and the control group. It is concluded that Nestorone prevents ovulation through inhibition of LH secretion and it has no effect on synthesis of LH. Progesterone receptors in pituitary might be involved in this process, but further study is needed to gain more evidence.     

The combined effects of participatory styles of elderly patients and their physicians on satisfaction

OBJECTIVES: To test whether concordance or discordance of patient participation between patients and physicians is associated with higher satisfaction, and to examine the effects of patients' and physicians' participatory styles on patients' satisfaction with their physicians. DATA: Data collected in the Texas Tech 5000 Survey of elderly patients in West Texas were used. Patient satisfaction with their physicians was measured by a single item from the Consumer Assessment of Health Plans (CAHPS), representing patients' ratings of their physicians. Patient participation was measured by an index derived from a three-item instrument and physicians' participatory decision-making (PDM) style was measured by a three-item instrument developed by the Medical Outcomes Study. METHODS: An ordered logit multivariate regression was used to investigate the effects of patients' and physicians' participatory styles on satisfaction with physicians. The interaction between patients' participation and physicians' participatory styles was also included to examine the dependency of the two variables. RESULTS: Controlling for confounding factors, a higher PDM score was associated with a higher rating of patient satisfaction with physicians. A higher patient participation score was related to a lower physician satisfaction rating. The combined effect of patients' and physicians' participation styles indicated that for a low patient participation score, a high PDM score was not needed to produce high satisfaction. The greater the discordance in this direction, the higher the satisfaction. However, with a high patient participation score, only an extremely high PDM score would produce relatively high satisfaction. CONCLUSIONS: The current study supports the discordance hypothesis. Participatory physicians and patient-physician communications concerning patient participation can promote higher satisfaction.     

A longitudinal examination of hospital registered nurse staffing and quality of care

OBJECTIVE: To evaluate previous research findings of the relationship between nurse staffing and quality of care by examining the effects of change in registered nurse staffing on change in quality of care. DATA SOURCES/STUDY SETTING: Secondary data from the American Hospital Association (AHA)(nurse staffing, hospital characteristics), InterStudy and Area Resource Files (ARF) (market characteristics), Centers for Medicare and Medicaid Services (CMS) (financial performance), and Healthcare Cost and Utilization Project (HCUP) (quality measures-in-hospital mortality ratio and the complication ratios for decubitus ulcers, pneumonia, and urinary tract infection, which were risk-adjusted using the Medstat disease staging algorithm). STUDY DESIGN: Data from a longitudinal cohort of 422 hospitals were analyzed from 1990-1995 to examine the relationships between nurse staffing and quality of care. DATA COLLECTION/EXTRACTION METHODS: A generalized method of moments estimator for dynamic panel data was used to analyze the data. Principal Findings. Increasing registered nurse staffing had a diminishing marginal effect on reducing mortality ratio, but had no consistent effect on any of the complications. Selected hospital characteristics, market characteristics, and financial performance had other independent effects on quality measures. CONCLUSIONS: The findings provide limited support for the prevailing notion that improving registered nurse (RN) staffing unconditionally improves quality of care.     

Black and green tea polyphenols attenuate blood pressure increases in stroke-prone spontaneously hypertensive rats

Oxidative stress was reported to be involved not only in cardiovascular diseases, but also in hypertension. Epidemiologic studies indicated that tea consumption slightly reduces blood pressure. We conducted two studies to determine whether black and green tea can lower blood pressure (BP) in stroke-prone spontaneously hypertensive rats (SHRSP). Male SHRSP (n=15) were allowed to recover for 2 wk after a transmitter for measuring BP was implanted in the peritoneal cavity. The rats were divided into three groups: the control group consumed tap water (30 mL/d); the black tea polyphenol group (BTP) consumed water containing 3.5 g/L thearubigins, 0.6 g/L theaflavins, 0.5 g/L flavonols and 0.4 g/L catechins; and the green tea polyphenol group (GTP) consumed water containing 3.5 g/L catechins, 0.5 g/L flavonols and 1 g/L polymetric flavonoids. The telemetry system was used to measure BP, which were recorded continuously every 5 min for 24 h. During the daytime, systolic and diastolic BP were significantly lower in the BTP and GTP groups than in the controls. Protein expressions of catalase and phosphorylated myosin light chain (MLC-p) were measured in the aorta by Western blotting. GTP significantly increased catalase expression, and BTP and GTP significantly decreased MLC-p expression in the aorta. These data demonstrate that both black and green tea polyphenols attenuate blood pressure increases through their antioxidant properties in SHRSP. Furthermore, because the amounts of polyphenols used in this experiment correspond to those in approximately 1 L of tea, the regular consumption of black and green tea may also provide some protection against hypertension in humans.     

Normal values for a clinical test of letter-recognition contrast thresholds

PURPOSE: To investigate the contrast thresholds (CTs) in normal subjects using a high-luminance, letter-recognition task under clinically relevant testing conditions. SETTING: Texas Tech University Health Sciences System, Lubbock, Texas, USA. METHODS: Sixty normal subjects aged 20 to 49 years with a best corrected visual acuity of 20/20 or better in both eyes participated. M & S Technologies software was used to display black-on-white Sloan letters at contrast levels of 25%, 20%, 15%, 12%, and 10% through 1% in 1% decrements. The effects of age, sex, optotype size, eye dominance, ambient illumination level (bright = 625 - 630 lux; dim = <3 lux), and direction of approach to threshold were analyzed using a multivariate, ordinary, least-squares analysis. RESULTS: Age and sex did not influence CTs. Ascending versus descending testing was not statistically significant (P>.5). The effects of room illumination and eye dominance were significant (P<.01). Significant differences were found between 20/30 and 20/50, 20/30 and 20/70, and 20/50 and 20/70 optotype sizes (P<.01 for all comparisons). CONCLUSIONS: A commercially available, computer-based test of CTs was easy to administer and apparently easy for inexperienced subjects to perform. The results suggest criteria for detecting visual problems concerned with familiar but complex spatial-image shapes. This information might be used to assess the effects of treatments such as laser refractive surgery on recognition contrast. Further study is warranted.     

Two new biologically active illudane sesquiterpenes from the mycelial cultures of Panaeolus retirugis

Two new illudane sesquiterpenes, paneolic acid and paneolilludinic acid, along with a known antibiotic diterpene, pleuromutilin, were isolated from the mycelial solid cultures of Panaeolus retirugis. Their structures were elucidated on the basis of spectroscopic analysis. Both compounds exhibited antibacterial activity against Staphylococcus aureus, and paneolic acid showed cytotoxicity to HL60 cell with an IC50 of 18.9 microg/ml.     

Design and synthesis of aryl diphenolic azoles as potent and selective estrogen receptor-beta ligands

New diphenolic azoles as highly selective estrogen receptor-beta agonists are reported. The more potent and selective analogues of these series have comparable binding affinities for ERbeta as the natural ligand 17beta-estradiol but are >100-fold selective over ERalpha. Our design strategy not only followed a traditional SAR approach but also was supported by X-ray structures of ERbeta cocrystallized with various ligands as well as molecular modeling studies. These strategies enabled us to take advantage of a single conservative residue substitution in the ligand-binding pocket, ERalpha Met(421) --> ERbeta Ile(373), to optimize ERbeta selectivity. The 7-position-substituted benzoxazoles (Table 5) were the most selective ligands of both azole series, with ERB-041 (117) being >200-fold selective for ERbeta. The majority of ERbeta selective agonists tested that were at least approximately 50-fold selective displayed a consistent in vivo profile: they were inactive in several models of classic estrogen action (uterotrophic, osteopenia, and vasomotor instability models) and yet were active in the HLA-B27 transgenic rat model of inflammatory bowel disease. These data suggest that ERbeta-selective agonists are devoid of classic estrogenic effects and may offer a novel therapy to treat certain inflammatory conditions.