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It has been proposed that the combinatorial expression of γ-protocadherins (Pcdh-γs) and other clustered protocadherins (Pcdhs) provides a code of molecular identity and individuality to neurons, which plays a major role in the establishment of specific synaptic connectivity and formation of neuronal circuits. Particular attention has been directed to the Pcdh-γ family, for which experimental evidence derived from Pcdh-γ-deficient mice shows that they are involved in dendrite self-avoidance, synapse development, dendritic arborization, spine maturation, and prevention of apoptosis of some neurons. Moreover, a triple-mutant mouse deficient in the three C-type members of the Pcdh-γ family (Pcdh-γC3, Pcdh-γC4, and Pcdh-γC5) shows a phenotype similar to the mouse deficient in whole Pcdh-γ family, indicating that the latter is largely due to the absence of C-type Pcdh-γs. The role of each individual C-type Pcdh-γ is not known. We have developed a specific antibody to Pcdh-γC4 to reveal the expression of this protein in the rat brain. The results show that although Pcdh-γC4 is expressed at higher levels in the embryo and earlier postnatal weeks, it is also expressed in the adult rat brain. Pcdh-γC4 is expressed in both neurons and astrocytes. In the adult brain, the regional distribution of Pcdh-γC4 immunoreactivity is similar to that of Pcdh-γC4 mRNA, being highest in the olfactory bulb, dentate gyrus, and cerebellum. Pcdh-γC4 forms puncta that are frequently apposed to glutamatergic and GABAergic synapses. They are also frequently associated with neuron-astrocyte contacts. The results provide new insights into the cell recognition function of Pcdh-γC4 in neurons and astrocytes.  相似文献   
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Background and objects: We explored the relationship between hospital/surgeon volume and postoperative severe sepsis/graft-failure (including death).Methods: The Taiwan National Health Insurance Research Database claims data for all patients with end-stage renal disease patients who underwent kidney transplantation between January 1, 1999, and December 31, 2007, were reviewed. Surgeons and hospitals were categorized into two groups based on their patient volume. The two primary outcomes were severe sepsis and graft failure (including death). The logistical regressions were done to compute the Odds ratios (OR) of outcomes after adjusting for possible confounding factors. Kaplan-Meier analysis was used to calculate the cumulative survival rates of graft failure after kidney transplantation during follow-up (1999-2008).Results: The risk of developing severe sepsis in a hospital in which surgeons do little renal transplantation was significant (odds ratio [OR]; p = 0.0115): 1.65 times (95% CI: 1.12-2.42) higher than for a hospital in which surgeons do many. The same trend was true for hospitals with a low volume of renal transplantations (OR = 2.39; 95% CI: 1.62-3.52; p < 0.0001). The likelihood of a graft failure (including death) within one year for the low-volume surgeon group was 3.1 times higher than for the high-volume surgeon group (p < 0.0001); the trend was similar for hospital volume. Female patients had a lower risk than did male patients, and patients ≥ 55 years old and those with a higher Charlson comorbidity index score, had a higher risk of severe sepsis.Conclusions: We conclude that the risk of severe sepsis and graft failure (including death) is higher for patients treated in hospitals and by surgeons with a low volume of renal transplantations. Therefore, the health authorities should consider exporting best practices through educational outreach and regulation and then providing transparent information for public best interest.  相似文献   
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The purpose of this study was to investigate the effect of smear layer and direction of dentinal tubules on osteoblast adhesion to human dentin tissue in vitro. Dentin disks were made from human premolars extracted for orthodontic reasons. Dentin disks were cut either perpendicularly to the long axis of the tooth or at 45 degrees to the long axis of tooth. The smear layer was removed by 34% phosphoric acid gel from half of the dentin disk surface. Human osteoblast-like Saos-2 cells were grown in RPMI medium with 10% fetal bovine serum and 1% antibiotic/antimycotic cocktail under standard cell culture conditions. Cells were seeded into Nunc four-well culture plates at 1.5 x 10(5) cells per well with dentin disks in the bottom of each well. After 1 day in culture the dentin disks along with cells grown on their surface were examined with a scanning electron microscopy. Osteoblasts attached and spread on the dentin surface and formed a monolayer in the presence and absence of a smear layer. Cells spread over the dentinal tubules despite their direction. These results suggest that cell adhesion and spreading of osteoblasts is not influenced either by the existence of a smear layer or the direction of the dentinal tubules on the dentin surface.  相似文献   
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