[Relationship of iron overload to bone mass density and bone turnover in postmenopausal women with fragility fractures of the hip].

OBJECTIVE: To study relationships between serum ferritin and bone metabolism in patients with hip fragility fractures. METHODS: This cross-sectional study included 76 postmenopausal women with hip fracture from Feburary 2011 to June 2012. The mean age of the women was (73 ± 10) years (range, 55-93 years) and the mean duration of menstruation was (22 ± 10)years (range, 5-50 years). Serum concentrations of ferritin, transferrin, alkaline phosphatase (ALP), amino-terminal extension peptide of type I collagen (P1NP), C-terminal telopeptides of type I collagen (ß-CTX)and femoral and lumbar bone mineral density by dual-energy X-ray absorptiometry were measured. Bone metabolism was compared between normal and elevated ferritin groups with t-test, Pearson linear, partial correlation and multiple regression analysis examined associations between iron- and bone-related markers. RESULTS: Serum ferritin concentration raised to (230 ± 146)µg/L, transferrin concentration reduced to (1.89 ± 0.33)g/L. P1NP concentration raised to (61 ± 32) ng/L when the concentration of serum ALP and ß-CTX were in the normal range. T-scores for bone mineral density in the femoral neck (-2.0 ± 1.1) and lumbar (-2.1 ± 1.2) were below the normal ranges(-1.0-1.0). The subjects were divided into two groups according to serum ferritin concentration, normal group(serum ferritin concentration ≤ 150 µg/L, n = 25) and elevated group(serum ferritin concentration > 150 µg/L, n = 51). Patients of elevated group had lower bone mineral density in femoral neck and lumbar than normal group(t = 3.13,2.89, P < 0.01), and higher P1NP, ß-CTX concentration (t = -2.38, -3.59, P < 0.05) . In partial correlation analysis adjusted for confounders, serum ferritin concentration was correlated negatively with bone mineral density in both femoral neck and lumbar (r = -0.335,-0.295, P < 0.05), and positively with P1NP and ß-CTX (r = 0.467,0.414, P < 0.05), but not correlated with ALP (r = 0.188, P > 0.05). Transferrin concentration tended to be correlated positively with bone mineral density in both femoral neck and lumbar (r = 0.444, 0.262, P < 0.05) and negatively with ALP, P1NP and ß-CTX(r = -0.326,-0.285,-0.278, P < 0.05). CONCLUSIONS: Iron overload has a high prevalence in postmenopausal women with fragility fracture. Increased iron stores, which might lead to bone loss and lower bone mineral density by enhancing the activity of bone turnover, could be an independent factor to take effects on bone metabolism on postmenopausal women.

Retrospective study to assess the effect of epidural analgesia on labor progress and women's pelvic floor muscle from the perspective of electromyography.

OBJECTIVE: Epidural analgesia has been widely used as a form of pain relief during labor and its safety has been gradually recognized. However, few studies of the effect of epidural analgesia on the pelvic floor are known. Thus, we aim to analyze the effect of epidural analgesia on labor progress and women's pelvic floor muscle from the perspective of electromyography systematically. In addition, obstetric risk factors for dysfunction of pelvic floor muscle after vaginal delivery were also evaluated. METHODS: Childbirth data of 124 primiparas who gave first birth vaginally in our hospital and their pelvic floor function assessment results at postpartum 7 weeks were retrospectively collected. Pelvic floor muscle electromyogram screenings were performed by a biofeedback electro-stimulant therapy instrument. RESULTS: There was no significant difference in the percentage of episiotomy, forceps, artificial rupturing membrane, and the application of oxytocin, except perineal laceration. Woman who implemented epidural analgesia experienced a longer stage of labor. Statistically, there was no significant difference in the total score and pelvic floor muscle strength. The risk factors for the value of the pre-rest phase include the age of pregnant women, the fetal weight, and the length of the second stage while the value of the post-rest phase was only associated with the fetal weight and the length of the second stage. In addition, the value of type I muscles was associated with the gravida and fetal weight while the value of type II muscles was only associated with forceps. The sustained contraction was correlated with the gravida and the total scores had a significant correlation with forceps. CONCLUSION: Epidural analgesia during labor is approved to be a safe and effective procedure to relieve pain with very low side effects on the mode of labor and pelvic floor muscle. The assessment of pelvic floor muscle before pregnancy is beneficial in guiding the better protection of pelvic floor muscle function. According to the evaluation results, the doctors can control the associated risk factors as much as possible to reduce the injury of pregnancy and parturition to the pelvic floor.

Application of a randomized response technique for the sensitive question survey in female sex workers in Xichang, China.

BACKGROUND: The technique of sampling is a particularly important aspect of sampling surveys, and the method of determining sample size is the key link in sampling technique. However, a sample size determination method for complex sampling surveys of sensitive issues using a randomized response model is not yet available. METHODS: In this work, we drew from the theory of probability and mathematical statistics, and developed a series of formulas for sample size determination that are required to estimate the overall proportion and mean on dichotomous sensitive questions in 3-stage sampling using Simmons models. RESULTS: Shortly after generating the formulas, we successfully applied them to a pre-survey regarding sensitive issues among female sex workers (FSWs) in Xichang, and found their practical application to achieve satisfactory effects. By using a large number of Monte Carlo simulation sampling tests, the reliability of the survey methods and formulas for sensitive question surveys were found to be high, but the randomized response technique (RRT) cannot completely eliminate the possibility of social acceptability bias. CONCLUSIONS: RRT is an acceptable method for sensitive question surveys within sensitive populations, and this new sampling method is liable to be used for sensitive question surveys of large populations. We believe that the results obtained in the field of public health can provide some data support for clinical practice.

Effects of 900-MHz microwave radiation on gamma-ray-induced damage to mouse hematopoietic system.

Exposure of humans simultaneously to microwave and gamma-ray irradiation may be a commonly encountered phenomenon. In a previous study data showed that low-dose microwave radiation increased the survival rate of mice irradiated with 8Gy gamma-ray; however, the mechanisms underlying these findings remain unclear. Consequently, studies were undertaken to examine the effects of microwave exposure on hematopoietic system adversely altered by gamma-ray irradiation in mice. Preexposure to low-dose microwaves attenuated the damage produced by gamma-ray irradiation as evidenced by less severe pathological alterations in bone marrow and spleen. The protective effects of microwaves were postulated to be due to up-expression of some hematopoietic growth factors, stimulation of proliferation of the granulocyte-macrophages in bone marrow, and inhibition of the gamma-ray induced suppression of hematopoietic stem cells/hematopoietic progenitor cells. Data thus indicate that prior exposure to microwaves may be beneficial in providing protection against injuries produced by gamma-ray on the hematopoietic system in mice.

[Radiation protection and possible mechanisms for low intensity microwave].

OBJECTIVE: To investigate radiation protection and possible mechanisms of low intensity microwave on gamma-ray exposed mice. METHODS: 96 healthy Kunming mice were randomly divided into the following four groups: normal control, microwave (120 microW/cm(2), 900 MHz), gamma-ray irradiation (5 Gy), combined exposure of microwave and gamma-ray (120 microW/cm(2) + 5 Gy). The microwave group and combined group were exposed to 120 microW/cm(2) microwave firstly, 1 h/d, for 14 days. Then the ionization and combined group were exposed to 5 Gy (60)Co gamma-ray irradiation on the 15th day. Animals were sacrificed on the third, 6th, 9th and 12th day after irradiation. The sternum and spleen paraffin section were produced, and the histological changes were observed. Apoptosis rate of mice splenic cells in each group was examined by flow cytometry, and serum concentration of antioxidant and lipid peroxide was detected at the same time. RESULTS: Bone marrow was obviously injured either by radiation or microwave exposure, characterized by undergoing four-phase lesions, namely apoptosis-necrosis, void, regeneration and recovery phase. Compared with the gamma-ray group, the pathological changes in combined group were slighter and the recovery was quicker. The pathological injuries of spleen were similar to that of bone marrow. Injuries in the combined group were slighter than gamma-ray group. It showed that apoptosis rate of splenic cells in combined group was significantly lower on the 6th and 9th day after gamma-ray radiation (23.02% +/- 15.18%, 25.37% +/- 11.62% respectively) from FCM results. Assays of oxidative damages suggested that serum superoxide dismutase (SOD) level in combined group increased while lipid peroxide level decreased significantly (P < 0.05). CONCLUSION: Low intensity microwave may exert protection effects on injuries induced by ionizing radiation. The underlying mechanisms might be related with suppression on the hematopoietic cells apoptosis induced by gamma-ray radiation, inhibition of oxidative damages, and thus enhanced reconstruction of the hematopoietic system.

[Antagonistic effect of microwave on hematopoietic damage of mice induced by gamma-ray irradiation].

OBJECTIVE: To investigate antagonistic effect of microwave on hematopoietic damage of mice induced by gamma-ray irradiation. METHODS: Male healthy Kunning mice were treated with low dose microwave radiation before exposure to (60)Co gamma-ray irradiation of 8.0 Gy. The 30-day survival rate and average survival time of the mice after the treatment were examined. Peripheral blood parameters and the organ indexes of thymus and spleen were also observed in the irradiated mice. After exposure to 5.0 Gy gamma irradiation, indexes of hematopoietic foci formation of bone marrow cells (CFU-GM) and the proliferation activity of BMNCs were examined. The serum concentration of hemopoietic factors (GM-CSF and IL-3) were detected by ELISA kits. RESULTS: Pre-exposure with 120 microW/cm(2) 900 MHz microwave increased the 30-day survival rate (P < 0.05) and the number of white blood cells of gamma-ray treated mice. The increases of the organ indexes of thymus and spleen, proliferation activity of BMNCs and CFU-GM hematopoietic foci numbers, as well as the higher serum concentration of GM-CSF and IL-3 were observed in the microwave pre-exposure group. CONCLUSION: Low dose microwave radiation may exert potential antagonistic effects on hematopoietic injuries induced by ionizing radiation. The underlying mechanisms might be related with stimulation of hematopoietic growth factors expression, promotion of HSCs/HPCs proliferation, suppression on the reduction of HSCs/HPCs caused by (60)Co gamma-ray, and enhanced construction of the hematopoietic system.

Estimation of Sensitive Proportion by Randomized Response Data in Successive Sampling.

This paper considers the problem of estimation for binomial proportions of sensitive or stigmatizing attributes in the population of interest. Randomized response techniques are suggested for protecting the privacy of respondents and reducing the response bias while eliciting information on sensitive attributes. In many sensitive question surveys, the same population is often sampled repeatedly on each occasion. In this paper, we apply successive sampling scheme to improve the estimation of the sensitive proportion on current occasion.

The Randomized Response Technique Application in the Survey of Homosexual Commercial Sex among Men in Beijing.

BACKGROUND: Traditional survey methods may cause refusals to respond or untruthful replies when encounter the sensitive questions. The Randomized Response Technique (RRT) is designed to decrease social desirability bias and obtain reliable estimates. This study aimed to apply these new methods on the sensitive questions survey. METHODS: Simmons model was applied in the survey of issues relevant to commercial sex among men who have sex with men (MSM) in Beijing, China. Stratified two-stage sampling and stratified random sampling were applied. RESULTS: During July to December 2010 in Beijing, the commercial sex proportion among MSM was 0.051(95% CI: 0.017, 0.085), its estimated variance was 3.01×10(-4). The last male condom use rate during commercial sex was 0.778(95% CI: 0.746, 0.810), its estimated variance was 2.6×10(-4). CONCLUSION: We have introduced new approaches for the sensitive question survey among MSM. The new approaches are proved to be reliable and valid.

The effect of combined exposure of 900 MHz radiofrequency fields and doxorubicin in HL-60 cells.

Human promyelocytic leukemia HL-60 cells were pre-exposed to non-ionizing 900 MHz radiofrequency fields (RF) at 12 µW/cm(2) power density for 1 hour/day for 3 days and then treated with a chemotherapeutic drug, doxorubicin (DOX, 0.125 mg/L). Several end-points related to toxicity, viz., viability, apoptosis, mitochondrial membrane potential (MMP), intracellular free calcium (Ca(2+)) and Ca(2+)-Mg(2+) -ATPase activity were measured. The results obtained in un-exposed and sham-exposed control cells were compared with those exposed to RF alone, DOX alone and RF+DOX. The results indicated no significant differences between un-exposed, sham-exposed control cells and those exposed to RF alone while treatment with DOX alone showed a significant decrease in viability, increased apoptosis, decreased MMP, increased Ca(2+) and decreased Ca(2+)-Mg(2+-)ATPase activity. When the latter results were compared with cells exposed RF+DOX, the data showed increased cell proliferation, decreased apoptosis, increased MMP, decreased Ca(2+) and increased Ca(2+)-Mg(2+)-ATPase activity. Thus, RF pre-exposure appear to protect the HL-60 cells from the toxic effects of subsequent treatment with DOX. These observations were similar to our earlier data which suggested that pre-exposure of mice to 900 MHz RF at 120 µW/cm(2) power density for 1 hours/day for 14 days had a protective effect in hematopoietic tissue damage induced by subsequent gamma-irradiation.

Induction of adaptive response: pre-exposure of mice to 900 MHz radiofrequency fields reduces hematopoietic damage caused by subsequent exposure to ionising radiation.

PURPOSE: To investigate whether an adaptive response can be induced in mice which were pre-exposed to 900 MHz radiofrequency fields. MATERIALS AND METHODS: Adult male Kunming mice were exposed to 900 MHz radiofrequency fields (RF) at power intensities of 12, 120 and 1200 µW/cm(2) for 1 h/day for 14 days and then subjected to whole body gamma-irradiation. The results were compared with those in unexposed control animals and those exposed to gamma-irradiation alone (without pre-exposure to RF). The extent of survival and hematopoietic tissue damage (assessed in the form of nucleated colony forming cells in the bone marrow and colony forming cells in the spleen of lethally irradiated 'recipient' mice) as well as the expression of cell cycle-related genes were investigated. RESULTS: The results indicated a significant increase in survival time, reduction in the hematopoietic tissue damage in RF pre-exposed mice which were gamma-irradiated (as compared with those exposed to gamma-radiation alone). This was accompanied by significantly increased expression of cell cycle-related genes, namely, cyclin-D1, cyclin-E, cyclin-DK4 and cyclin-DK2 in hematopoietic cells. CONCLUSIONS: Pre-exposure of mice to 900 MHz radiofrequency fields has resulted in a significant reduction in hematopoietic damage caused by subsequent exposure to ionising radiation. This phenomenon appears to be similar to that of the 'adaptive response' which is well documented in scientific literature.