An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti

Ingestion of vertebrate blood is essential for egg maturation and transmission of disease-causing parasites by female mosquitoes. Prior studies with the yellow fever mosquito, Aedes aegypti, indicated blood feeding stimulates egg production by triggering the release of hormones from medial neurosecretory cells in the mosquito brain. The ability of bovine insulin to stimulate a similar response further suggested this trigger is an endogenous insulin-like peptide (ILP). A. aegypti encodes eight predicted ILPs. Here, we report that synthetic ILP3 dose-dependently stimulated yolk uptake by oocytes and ecdysteroid production by the ovaries at lower concentrations than bovine insulin. ILP3 also exhibited metabolic activity by elevating carbohydrate and lipid storage. Binding studies using ovary membranes indicated that ILP3 had an IC(50) value of 5.9 nM that was poorly competed by bovine insulin. Autoradiography and immunoblotting studies suggested that ILP3 binds the mosquito insulin receptor (MIR), whereas loss-of-function experiments showed that ILP3 activity requires MIR expression. Overall, our results identify ILP3 as a critical regulator of egg production by A. aegypti.     

Predictors of disease-related concerns and other aspects of health-related quality of life in outpatients with inflammatory bowel disease

OBJECTIVE: Disease-related concerns are a major dimension of health-related quality of life in inflammatory bowel disease (IBD). The aim of this study was to assess the concerns of IBD patients in an outpatient sample, and to determine the impact of psychological and disease factors on concerns and on other variables of health-related quality of life. METHODS: Seventy-two outpatients with IBD were assessed with regard to disease-related concerns [with the Rating Form of IBD Patients' Concerns (RFIPC)], psychological symptoms and somatic complaints non-specific to IBD as dependent variables. Coping with illness, health locus of control, and disease variables were assessed as predictor variables. Multiple regression analyses determined the independent contribution of each predictor on the dependent variables. RESULTS: Women reported more intense concerns than men. No difference in concerns was found between patients with Crohn's disease and ulcerative colitis. The highest predictive value for the RFIPC total score was found for depressive coping. It explained a greater proportion of variance on the RFIPC total score (23%) than demographic (10%) and disease variables (7%), and comparably impinged on RFIPC subscores. Furthermore, depressive coping was significantly associated with psychological distress, the self-rated health status and somatic complaints non-specific to IBD. CONCLUSIONS: Our findings suggest that in IBD psychological variables, particularly depressive coping, are more predictive than medical variables for disease-related concerns and other variables of health-related quality of life. Further studies are needed to examine the effects that the way of coping with disease have on long-term outcome in IBD.     

New shift models for doctors in a large German University Neurosurgery Department: how they comply with the European Working Time Directive 3 years after implementation

Background

Due to the European Working Time Directive (EWTD) and a new collective agreement for doctors working at University hospitals in 2006 new shift models had to be designed in the Department of Neurosurgery of the University Hospital Tübingen, Germany. The aim of the study was to show the fit of the models regarding the average weekly working time limits (aWTL), the daily maximum of 10-h working time (10-h dWT), and the staff expenditures 3 years after implementation.

Methods

The new shift model was implemented in 2008, and hence planning and documentation were done electronically. Adherence to the work schedules was measured, and aWTL adherence rates were compared. The relative number of 10-h dWT violations in 2009 and 2010 was analysed. Staff costs relative to performance before and after implementation were calculated and tested using analysis of variance (ANOVA). Four other departments without alteration of shift models served as a control group in cost trend analysis.

Results

In 2010 all doctors in the Department of Neurosurgery were able to stay within the limit of 54 h/week; one doctor without opt-out exceeded the 48 h/week limit (50.1 h/week). The median per capita rate of 10-h dWT violations in 2009 was 20.3 % of all eligible working days and further declined to 10.7 % in 2010 (p?Conclusions After implementation of the new shift model, current monitoring and properly matching modifications led to long-term stability in complying with the EWTD regulations without increasing costs for staff expenditures.     

Microcracks and Osteoclast Resorption Activity In Vitro

During bone remodeling osteoclasts resorb bone, thus removing material, e.g., damaged by microcracks, which arises as a result of physiological loading and could reduce bone strength. Such a process needs targeted bone resorption exactly at damaged sites. Osteocytic signaling plays a key role in this process, but it is not excluded that osteoclasts per se may possess toposensitivity to recognize and resorb damaged bone since it has been shown that resorption spaces are associated with microcracks. To address this question, we used an in vitro setup of a pure osteoclast culture and mineralized substrates with artificially introduced microcracks and microscratches. Histomorphometric analyses and statistical evaluation clearly showed that these defects had no effect on osteoclast resorption behavior. Osteoclasts did not resorb along microcracks, even when resorption started right beside these damages. Furthermore, quantification of resorption on three different mineralized substrates, cortical bone, bleached bone (bone after partial removal of the organic matrix), and dentin, revealed lowest resorption on bone, significantly higher resorption on bleached bone, and highest resorption on dentin. The difference between native and bleached bone may be interpreted as an inhibitory impact of the organic matrix. However, the collagen-based matrix could not be the responsible part as resorption was highest on dentin, which contains collagen. It seems that osteocytic proteins, stored in bone but not present in dentin, affect osteoclastic action. This demonstrates that osteoclasts per se do not possess a toposensitivity to remove microcracks but may be influenced by components of the organic bone matrix.     

Re‐establishment of cytoskeletal tensional homeostasis in lax tendons occurs through an actin‐mediated cellular contraction of the extracellular matrix

Cytoskeletal tensional homeostasis is known to be an important factor in controlling catabolic gene expression in tendon cells. Loss of cell tension in lax rat tail tendon fascicles (RTTfs) has been associated with an upregulation of MMP‐13 gene expression and protein synthesis. To determine the role of the actin cytoskeleton in re‐establishing tensional homeostasis in lax tendons, RTTfs were allowed to freely contract in vitro for 8 days. The cultured RTTfs contracted rapidly, reaching 50% of their initial length by 3 days. This contraction was associated with the presence of α‐smooth muscle actin positive cells within the tendon. Disruption of the actin network by cytochalasian D caused an immediate and significant elongation of the contracted RTTfs. Subsequent removal of the cytochalasian D re‐initiated the contraction process. When lax RTTfs were allowed to contract between fixed clamps in culture and become taut, they demonstrated a marked decrease in MMP‐13 staining intensity when compared to freely contracting RTTfs. The ability of native tendon cells to contract lax tendons and re‐establish their homeostatic “set point” with respect to collagenase production may be an important mechanism in the recovery of tendons elongated by injury, surgical positioning, or cyclic, viscoelastic creep secondary to repetitive exercise. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1695–1701, 2012     

Impact of measuring multiple or single occlusal lesions on estimates of diagnostic accuracy using fluorescence methods

Carious lesions can occur at different sites on the occlusal surfaces of teeth and may differ in appearance and severity. This study aimed to evaluate how scoring several lesions on occlusal surfaces, as opposed to only one representative lesion, affects estimates of reproducibility and accuracy of fluorescence-based devices. Thirty-six permanent teeth with 2-3 investigation sites (n = 82) were examined by two examiners using the laser fluorescence device DIAGNOdent pen (LF) and the fluorescence camera VistaProof (FC). Lesion depth was then assessed histologically in serial sections of the teeth. Intra-class-correlation coefficients (ICC) and areas under the ROC-curves were calculated for all investigation sites and for one randomly selected site per tooth. Comparing the reproducibility and the performance for the whole sample and the independent sites showed only a small effect or no effect. Measuring multiple sites on teeth with fluorescence devices only moderately influences performance compared to one site being investigated.     

The early decline in renal function in patients with type 1 diabetes and proteinuria predicts the risk of end-stage renal disease

The risk of end-stage renal disease (ESRD) remains high in patients with type 1 diabetes and proteinuria; however, little is known about the rate of decline in their renal function. To help determine this, we enrolled patients with type 1 diabetes and proteinuria whose estimated glomerular filtration rate (eGFR) was normal (equal to or above 60?ml/min per 1.73?m(2)). Using a minimum of five serial measurements of serum creatinine for 161 patients, we determined individual trajectories of eGFR change and the occurrence of ESRD during 5-18 years of follow-up. The rates were linear for 110 patients, for 24 the nonlinear rate was mild enough to satisfy a linear model, and the rates were clearly nonlinear for only 27 patients. Overall, in more than one-third of patients, the eGFR decline was less than 3.5?ml/min per 1.73?m(2) per year and the lifetime risk of ESRD could be considered negligible. In the remainder of patients, eGFR declined with widely different slopes and ESRD developed within 2 to 18 years. Based on up to 5 years observation, when renal function was within the normal range, the estimates of early eGFR slope predicted the risk of ESRD during subsequent follow-up better than the baseline clinical characteristics of glycated hemoglobin, blood pressure, or the albumin to creatinine ratio. Thus, the early slope of eGFR decline in patients with type 1 diabetes and proteinuria can be used to predict the risk of ESRD.