Structure of outer membrane protein G by solution NMR spectroscopy

The bacterial outer membrane protein G (OmpG), a monomeric pH-gated porin, was overexpressed in Escherichia coli and refolded in beta-octyl glucoside micelles. After transfer into dodecylphosphocholine micelles, the solution structure of OmpG was determined by solution NMR spectroscopy at pH 6.3. Complete backbone assignments were obtained for 234 of 280 residues based on CA, CB, and CO connection pathways determined from a series of TROSY-based 3D experiments at 800 MHz. The global fold of the 14-stranded beta-barrel was determined based on 133 long-range NOEs observed between neighboring strands and local chemical shift and NOE information. The structure of the barrel is very similar to previous crystal structures, but the loops of the solution structure are quite flexible.     

Season of birth in siblings of patients with seasonal affective disorder

Recently we have published a report on seasonally varying birth rates in 553 patients with seasonal affective disorder (SAD). The present study is aimed to test the hypothesis of an idiosyncratic seasonal conception pattern of the parents of these patients to explain this phenomenon. We conducted a telephone interview with the patients to obtain information on the birth data of their siblings. Using the method of chart review to acquire information on the family history of our patients, we excluded those siblings with psychiatric disorders. We first compared the birth months and the quarters of birth of 435 healthy siblings with the general population. Secondly, we compared the birth distribution of the index SAD patients with that of their siblings. There was a significant deviation between the birth distribution of the siblings and the general population calculated on a monthly basis (p = 0.044). When comparing quarters we found less births than expected in the first (-14.1%) and fourth quarter of the year (-15.1%) and an excess of births in the second (+7.7%) and third quarter (+21.1%; p = 0.018). There were no significant differences between the group of SAD patients and their siblings regarding their birth patterns as calculated by months (p = 0.848) or quarters (p = 0.320). Our study provides support for the hypothesis of specific parental conception habits underlying the birth seasonality in SAD. Further research could be conducted in non-seasonal depression as there is still a lack of studies on seasonality of birth in affective disorders.     

Nerve conduits and growth factor delivery in peripheral nerve repair

Peripheral nerves possess the capacity of self-regeneration after traumatic injury. Transected peripheral nerves can be bridged by direct surgical coaptation of the two nerve stumps or by interposing autografts or biological (veins) or synthetic nerve conduits (NC). NC are tubular structures that guide the regenerating axons to the distal nerve stump. Early synthetic NC have primarily been made of silicone because of the relative flexibility and biocompatibility of this material and because medical-grade silicone tubes were readily available in various dimensions. Nowadays, NC are preferably made of biodegradable materials such as collagen, aliphatic polyesters, or polyurethanes. Although NC assist in guiding regenerating nerves, satisfactory functional restoration of severed nerves may further require exogenous growth factors. Therefore, authors have proposed NC with integrated delivery systems for growth factors or growth factor-producing cells. This article reviews the most important designs of NC with integrated delivery systems for localized release of growth factors. The various systems discussed comprise NC with growth factors being released from various types of matrices, from transplanted cells (Schwann cells or mesenchymal stem cells), or through genetic modification of cells naturally present at the site of injured tissue. Acellular delivery systems for growth factors include the NC wall itself, biodegradable microspheres seeded onto the internal surface of the NC wall, or matrices that are filled into the lumen of the NC and immobilize the growth factors through physical-chemical interactions or specific ligand-receptor interactions. A very promising and elegant system appears to be longitudinally aligned fibers inserted in the lumen of a NC that deliver the growth factors and provide additional guidance for Schwann cells and axons. This review also attempts to appreciate the most promising approaches and emphasize the importance of growth factor delivery kinetics.     

Reduction of overall treatment time in patients irradiated for more than three brain metastases

PURPOSE: Patients with multiple brain metastases usually receive whole brain radiotherapy (WBRT). A dose of 30 Gy in 10 fractions (10 x 3 Gy) in 2 weeks is the standard treatment in many centers. Regarding the poor survival of these patients, a shorter RT regimen would be preferable if it provides a similar outcome as that with 10 x 3 Gy. This study compared 20 Gy in five fractions (5 x 4 Gy) within 5 days to 10 x 3 Gy. METHODS AND MATERIALS: Data from 442 patients treated with WBRT for multiple brain metastases were retrospectively analyzed. Survival and local control within the brain of 232 patients treated with 5 x 4 Gy were compared with the survival and local control within the brain of 210 patients treated with 10 x 3 Gy. Seven additional potential prognostic factors were investigated: age, gender, Karnofsky performance score, tumor type, interval from tumor diagnosis to RT, extracranial metastases, and recursive partitioning analysis class. RESULTS: On univariate analysis, the WBRT program was not associated with survival (p = 0.29) or local control (p = 0.07). On multivariate analyses, improved survival was associated with a lower recursive partitioning analysis class (p < 0.001), age or=70 (p = 0.015), and the absence of extracranial metastases (p = 0.005). Improved local control was associated with a lower recursive partitioning analysis class (p < 0.001), Karnofsky performance score >or=70 (p < 0.001), and breast cancer (p = 0.043). Grade 3 acute toxicity rates were not significantly different between 5 x 4 Gy and 10 x 3 Gy. CONCLUSIONS: Shorter course WBRT with 5 x 4 Gy was associated with similar survival and local control as "standard" WBRT with 10 x 3 Gy in patients with more than three brain metastases. The 5 x 4-Gy regimen appears preferable for most of these patients, because it is less time consuming and more convenient for patients than the 10 x 3-Gy regimen.     

Increased pulmonary FDG uptake in bleomycin-associated pneumonitis

BACKGROUND: Bleomycin is an antineoplastic agent that is mainly used in combination regimens. Dose-limiting toxicity is the bleomycin-induced pneumonitis (BIP) that can be diagnosed by clinical and radiological findings. The early diagnosis of BIP is often challenging. CASE REPORT: We report the occurrence of a diffuse pulmonary increase of FDG uptake in the FDG-PET scan in association with suspected BIP in a patient treated for relapsed seminoma. A retroperitoneal relapse was treated with a combination chemotherapy containing cisplatin, etoposide, and bleomycin. After 3 cycles of this regimen the patient developed mild clinical signs of early BIP. A following FDG-PET in order to evaluate treatment response showed a diffuse increased FDG uptake of the right lung. The subsequent HRCT revealed pathological findings consistent with BIP. After cessation of bleomycin and a systemic steroid trial a prompt normalization of the abnormal radiological and clinical findings occurred together with a disappearance of the increased pulmonary FDG uptake. CONCLUSION: FDG-PET can be used for evaluation of residual disease in patients treated for advanced seminoma. In cases of otherwise unexplained increased pulmonary FDG uptake in patients under treatment with bleomycin an evaluation for early BIP as a possible cause of this finding is warranted.     

Loss‐of‐function of MYO5B is the main cause of microvillus inclusion disease: 15 novel mutations and a CaCo‐2 RNAi cell model

Autosomal recessive microvillus inclusion disease (MVID) is characterized by an intractable diarrhea starting within the first few weeks of life. The hallmarks of MVID are a lack of microvilli on the surface of villous enterocytes, occurrence of intracellular vacuoles lined by microvilli (microvillus inclusions), and the cytoplasmic accumulation of periodic acid‐Schiff (PAS)‐positive vesicles in enterocytes. Recently, we identified mutations in MYO5B, encoding the unconventional type Vb myosin motor protein, in a first cohort of nine MVID patients. In this study, we identified 15 novel nonsense and missense mutations in MYO5B in 11 unrelated MVID patients. Fluorescence microscopy, Western blotting, and electron microscopy were applied to analyze the effects of MYO5B siRNA knock‐down in polarized, brush border possessing CaCo‐2 cells. Loss of surface microvilli, increased formation of microvillus inclusions, and subapical enrichment of PAS‐positive endomembrane compartments were induced in polarized, filter‐grown CaCo‐2 cells, following MYO5B knock‐down. Our data indicate that MYO5B mutations are a major cause of microvillus inclusion disease and that MYO5B knock‐down recapitulates most of the cellular phenotype in vitro, thus independently showing loss of MYO5B function as the cause of microvillus inclusion disease. Hum Mutat 31:1–8, 2010. © 2010 Wiley‐Liss, Inc.