Longitudinal in vivo effects of growth hormone overexpression on bone in transgenic mice.

In this study we examined the effect of systemic overexpression of GH on bone in transgenic mice longitudinally in vivo over a period of 9 months. We observed substantially increased BMC in GH transgenic mice and a significant reduction in serum osteocalcin. GH effects on bone were strongly dependent on gender and developmental stage. INTRODUCTION: State-of-the-art bone marker and microimaging technology was applied in this longitudinal study to examine bone metabolism, BMC, bone density, and cortical bone structure over the life span of growth hormone (GH) transgenic (tg) mice. MATERIALS AND METHODS: Thirty-eight mice from four genetic groups (male, female, tg, and controls) were examined with DXA, and their femur and tibia were examined with peripheral QCT (pQCT). Osteocalcin (formation) and collagen cross-links (resorption) from serum and urine were also measured at postnatal weeks 3, 6, 9, 12, 18, 26, and 38. RESULTS: GH tg mice displayed a significant increase in body weight (up to 50%) and BMC (up to 90%), but serum osteocalcin was significantly reduced compared with controls. GH tg females (but not males) displayed increased trabecular density over controls up to week 12. In contrast, male (but not female) GH tg mice displayed a higher cortical cross-sectional area than controls. Cortical density was significantly lower in both male and female GH tg mice compared with control mice. CONCLUSIONS: The increase in BMC in GH tg mice is associated with reduced serum osteocalcin levels, indicating that bone turnover may be lower than in the control mice. On a structural level, bone responds to GH excess in a gender-specific manner, with alterations varying substantially between different developmental stages.     

Morphological changes in mesothelial cells induced by shed menstrual endometrium in vitro are not primarily due to apoptosis or necrosis

In a previous study on the pathogenesis of endometriosis, we observed that constituents of menstrual effluent induce morphological alterations in human mesothelial cells. In this study, we investigated whether these alterations were associated with apoptosis or necrosis or were the result of cellular remodelling. After overnight incubation of confluent monolayers of human omental mesothelial cells (HOMEC) with conditioned media prepared from menstrual effluent shed anterogradely, severe alterations in morphology were observed. Typical polygonal mesothelial cell cultures at confluency acquired elongated spindle morphology, resulting in gaps between the cells. In contrast, mesothelial cells from the control groups receiving culture medium only, retained a normal morphology. Immunofluorescence staining revealed that cytokeratin, vimentin and actin filaments were still present, homogeneously distributed in the cell cytoplasm following changes in morphology. To evaluate whether the morphological alterations were associated with apoptosis and/or necrosis, the cells were stained with the M30 CytoDeath antibody or annexin V with propidium iodide and analysed using flow cytometry. The results showed that only a small percentage (1-7%) of the affected HOMEC were undergoing apoptosis or necrosis. We conclude that the profoundly altered morphology of HOMEC is a result of cellular remodelling and that the role of apoptosis and necrosis is negligible. Soluble paracrine factors released by cells isolated from menstrual effluent shed anterogradely may induce a reorganization of the cytoskeleton. As a result, the underlying basement membrane will be exposed and the mesothelium may no longer prevent implantation of endometrium shed retrogradely into the peritoneum, thus facilitating the development of endometriosis.     

感知胃灼热和反胃的决定因素

背景与目的：目前尚不清楚为什么有些胃食管反流会引起症状，而有些不会。作者对患者感知胃食管反流的决定因素进行了调查。方法：在抑酸治疗停止后对32例提示有胃食管反流症状的患者进行24h便携式pH值和阻抗监测。对其中至少发生一次反流事件的20例患者，根据有无反流症状进行比较。结果：共监测到1807次反流事件的发生，其中的203次反流伴有症状。与无症状的反流事件相比，有症状的反流与较大的pH值降低幅度（P〈0．001）、低pH值（P〈0．05）和较高的食管近端酸反流程度（P〈0．005）相关。有症状的反流有着较长的容积恢复时间和酸清除时间（P〈0．05和P〈0．002）。在有症状的反流发生之前通常存在一段较长的食管累积酸暴露时间（P〈0．05）。反胃与胃灼热相比，在反胃之前的近端酸反流程度较大；14．8％的症状性反流是弱酸性的。共有426例纯气体反流发生，其中12例伴有症状。与无症状的纯气体反流相比，症状性纯气体反流更多伴随有pH值减少（P〈0．05）。     

Sensitivity studies for quantitative assays: use of censored data analysis

Probit regression analysis is frequently used to study the relation between the concentration of an analyte in a sample and the probability that the assay used yields a positive test result. For these analyses only the qualitative classification 'positive' or 'negative' is used, whereas, particularly in the case where the assay is quantitative in nature, the results contain more information. In the current paper, we propose an alternative method, in which the negative test results are treated as being (left) censored. As such, more efficient use is made of the information in the data. The procedures are illustrated using two generations of NucliSens assays (BioMérieux), which are designed to quantify the viral load of HIV-1 in blood samples. Computer simulations are used to illustrate some properties of the estimated parameters.     

Double-Peaked High-Pressure Zone at the Esophagogastric Junction in Controls and in Patients with a Hiatal Hernia: A Study Using High-Resolution Manometry

The lower esophageal high-pressure zone (HPZ) consists of the intrinsic lower esophageal sphincter (LES) and the diaphragmatic sphincter. In patients with a hiatal hernia these constituents are separated. We performed high-resolution manometry of the esophagogastric HPZ in six controls, six patients with a small hernia, and six patients with a large hernia. Prevalence of a double-peak pressure profile of the HPZ was noted. Pressures and distances between the peaks were assessed. Prevalence of the double-peak profile was similar between patients with a small hernia and controls, but patients with a large hernia showed a higher prevalence with inspiration (P < 0.05) than the others. The distance between the two peaks was larger in patients with a large hernia (P < 0.05). In conclusion, high-resolution manometry makes it possible to distinguish the diaphragmatic pressure component from the LES. Two pressure peaks can be found both in hernia patients and in healthy volunteers.     

A stochastic model of the processes in PCR based amplification of STR DNA in forensic applications

In forensic DNA profiling use is made of the well-known technique of PCR. When the amount of DNA is high, generally unambiguous profiles can be obtained, but for low copy number DNA stochastic effects can play a major role. In order to shed light on these stochastic effects, we present a simple model for the amplification process. According to the model, three possible things can happen to an individual single DNA strand in each complete cycle: successful amplification, no amplification, or amplification with the introduction of stutter. The model is developed in mathematical terms using a recursive approach: given the numbers of chains at a given cycle, the numbers in the next can be described using a multinomial probability distribution. A full set of recursive relations is derived for the expectations and (co)variances of the number of amplicon chains with no, 1 or 2 stutters. The exact mathematical solutions of this set are given, revealing the development of the expectations and (co)variances as function of the cycle number. The equations reveal that the expected number of amplicon chains without stutter grows exponentially with the cycle number, but for the chains with stutter the relation is more complex. The relative standard deviation on the numbers of chains (coefficient of variation) is inversely proportional to the square root of the expected number of DNA strands entering the amplification. As such, for high copy number DNA the stochastic effects can be ignored, but they play an important role at low concentrations. For the allelic peak, the coefficient of variation rapidly stabilizes after a few cycles, but for the chains with stutter the decrease is more slowly. Further, the ratio of the expected intensity of the stutter peak over that of the allelic peak increases linearly with the number of cycles. Stochastic models, like the one developed in the current paper, can be important in further developing interpretation rules in a Bayesian context.     

Purification and Characterization of DSIP-Like Material From Ovine Pineal Glands: Possible Peptide-Protein Interaction

The nonapeptide delta-sleep-inducing peptide (DSIP) has been isolated from venous blood of rabbits induced to sleep. Numerous reports have described sleep as well as extra-sleep effects. Radiochemical and immunochemical data suggest a relationship of DSIP with the pineal gland supported by interactions of this peptide with pineal functions such as the serotonin N-acetyltransferase activity. In order to demonstrate the natural occurrence of DSIP-like material associated with high Mr proteins in the ovine pineal, organs were water-extracted and fractionated by ultrafiltration and gel filtration. Radioimmunoassay (RIA) for DSIP-like fragments of the fractions revealed considerable amounts of pineal DSIP-like immunoreactivity (DSIP-LI) apparently existing in small as well as large molecular forms. Acidification of large DSIP-LI forms resulted in the elution from Sephadex G-50 of Mr less than or equal to 1,000 DSIP-like material. This free DSIP-LI form coeluted with the synthetic DSIP nonapeptide from microBondapak C18 on high-performance liquid chromatography. The results, therefore, appear to indicate the presence of a (biospecific) noncovalent intermolecular interaction of DSIP (1-9) with proteins (Mr greater than or equal to 10,000) of the ovine pineal gland.     

Fluvoxamine in the treatment of menstrually related mood disorders

Twenty women with premenstrual complaints were treated in a double-blind placebo controlled trial during two consecutive menstrual cycles with fluvoxamine, a selective serotonin uptake blocker. A beneficial effect was found on somatic and affective symptoms in both treatment groups, the effect of fluvoxamine being not different from placebo. The results of this study do not support a role for serotonin in menstrually related affective symptoms.