Postnatal development of intrinsic GABAergic rhythms in mouse hippocampus

The local circuitry of the mammalian limbic cortices, including the hippocampus, is capable of generating spontaneous rhythmic activities of 0.5-4 Hz when isolated in vitro. These rhythmic activities are mediated by synchronous inhibitory postsynaptic potentials in pyramidal neurons as the result of repeated discharges of inhibitory interneurons. As such, they are thought to represent an intrinsic inhibitory rhythm. It is unknown at present whether such a rhythm occurs in the immature rodent hippocampus and, if so, the postnatal time window in which it develops. We explored these issues using our recently developed whole mouse hippocampal isolate preparation in vitro. We found that spontaneous rhythmic field potentials started to emerge in mouse hippocampal isolates around postnatal day 10, stabilized after postnatal day 15 and persisted into adulthood. In postnatal days 11-14 mouse hippocampi, the properties of these rhythmic potentials were in keeping with a CA3-driven, IPSP-based intrinsic network activity. The lack of spontaneous field rhythm in neonatal (postnatal days 2-7) hippocampi cannot be attributed to the excitatory activities mediated by gamma-aminobutyric acid type A (GABA-A) receptors, as chloride-dependent hyperpolarizing inhibitory postsynaptic potentials were detectable in neonatal pyramidal neurons at voltages near resting potentials and pharmacological antagonisms of GABA-A receptors produced robust epileptiform discharges in neonatal hippocampi. High frequency afferent stimulation or applications of 4-aminopyridine at low micromolar concentrations failed to induce persistent field rhythm in neonatal hippocampi, suggesting that an overall weak glutamatergic drive is not the sole causing factor. We suggest that the inhibitory postsynaptic potential-based spontaneous rhythmic field potentials develop in a discrete time window during the second postnatal week in the mouse hippocampus due to a fine-tuning in the structure and function of CA3 recurrent circuitry and associated GABAergic inhibitory interneurons.     

Association of genetic polymorphisms and haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma

OBJECTIVE: To explore the relationship of the genetic polymorphisms and the haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma (PTC) in Chinese Hans. METHODS: A hospital based 1:1 matched case-control study was carried out. The polymorphisms for 204 pairs of PTC cases and healthy controls were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific oligonucleotide (PCR-ASO) assays. RESULTS: (1) The PTC risk was marginally increased in the hMLH1 1151TA genotype, with odds ratio (OR) of 2.15 (95%CI: 0.99-4.85); the PTC risk was significantly increased in the mutant genotype 1151TA+AA, with OR of 2.15 (95%CI: 1.02-4.69); (2) The haplotypes of -93G, 1151A, 655A in the hMLH1 gene could increase the PTC risk, with OR of 2.67 (95%CI: 1.16-6.53, P=0.011), compared with the haplotype of -93G, 1151T, 655A; (3) Compared to 3124A, 2835G haplotype in hMSH3 gene, the 3124G, 2835A haplotype could increase the PTC risk marginally, with OR of 3.08 (95%CI: 0.92-13.25). CONCLUSION: The 1151T/A polymorphism in hMLH1 was associated with PTC; both the haplotype of -93G, 1151A, 655A in hMLH1 and the 3124G, 2835A haplotype in hMSH3 were associated with PTC.     

Alpha-methylacyl-CoA racemase/P504S overexpression in colorectal carcinoma is correlated with tumor differentiation.

Alpha-methylacyl-CoA racemase (AMACR)/P504S is an enzyme involved in the metabolism of branched-chain fatty acids. Little is known about correlation of AMACR expression with colorectal carcinoma (CRC) differentiation and prognosis. We investigated the expression of AMACR in 106 cases of primary CRC, and in 47 lymph nodes with metastatic CRC by immunohistochemical analysis. These cases were divided into 3 groups according to the histologic differentiation of the primary tumors. group A included 50 cases of histologically well and moderately differentiated CRCs, 20 of these with lymph node metastasis; group B included 23 cases of well and moderately differentiated CRCs, histologically similar to group A, except these tumors had small foci (less than 20%) of high-grade carcinoma, and 10 of these had lymph node metastasis; group C included 33 cases of poorly differentiated adenocarcinoma and undifferentiated carcinoma, 17 with lymph node metastasis. The results showed the overall positive rates of expression in primary and metastatic CRCs were 59.4% and 46.8%, respectively. Expression in groups A (76.0%) and B (69.6%) was much higher than that in group C (27.3%). In group B, although overexpression of AMACR in primary tumors was similar to that of group A, it was only seen in 30.0% of group B metastatic tumors, which was similar to the rate of expression in group C (23.5%). In contrast, rates of expression in group A primary and metastatic tumors were similar (80.0% and 75.0%). Positive staining for AMACR in benign epithelium adjacent to tumor was rare (<2%). No relation was found between AMACR expression and overall survival. Our findings support the view that the expression of AMACR in CRC is correlated with tumor differentiation.     

辅酶Q10对兔膈肌疲劳的作用

实验以膈肌肌电图（ＥＭＧｄｉ）及膈肌诱发电位为指标，观察辅助酶Ｑ１０对兔膈肌作用，发现：（１）复制膈肌疲劳（ＤＩＦ）后静脉注射ＣｏＱ１０ｍｇ／ｋｇ，对ＤＩＦ有治疗作用，（２）提前１静脉注射ＣｏＱ１０１０ｍｇ／ｋｇ预处理，对电致作膈肌有保护作用。     

丹参对缺血心肌的保护作用

目的:通过观察丹参注射液(DSZ)对缺血心肌细胞各项生化指标的影响,探讨其对心肌保护作用及其机制。方法:将小鼠随机分为四组,以40%丹参注射液0.25ml/10g灌胃处理,一周后腹腔注射垂体后叶素(Pit),复制心肌缺血模型,观察小鼠心肌组织一氧化氮合酶(NOS)及超氧化物岐化酶(SOD)活性、脂质过氧化物丙二醛(MDA)的含量、血清肌酸激酶(CK)活性。结果:DSZ预处理小鼠心肌组织NOS、SOD活性显著增加,而MDA的含量及血清CK活性显著降低(P<0.01)。结论:丹参减轻心肌缺血引发的损伤,保护心脏,其作用机制可能与增加缺血心肌组织NOS、SOD活性,减少MDA含量和血清CK活性有关。     

Early-life epileptiform discharges exert both rapid and long-lasting effects on AMPAR subunit composition and distribution in developing neurons

The perinatal period of brain is characterized by dynamic changes in structure and high propensity for epilepsy. Animal models have shown that alterations of AMPA receptor (AMPAR) assembly or function may be related to seizure-induced cell damage, long-lasting impairments in brain development and seizure threshold. However, effects of earlier epileptiform discharges on AMPAR composition and sub-cellular distribution remain understudied. In this study, we analyzed age-dependent variation of relative GluR1 and GluR2 protein levels in primary cultured rat cortical neurons at 7 DIV, 12 DIV, 17 DIV and 21 DIV. By inducing a single event of epileptiform activity at 6 DIV, we tested the effects of early-life seizure-like insults on AMPAR subunit distribution. We found a significant increase in synaptosomal membrane GluR1 expression in magnesium-free (MGF) medium-treated neurons at each time point detected (p < 0.05), while GluR2 expression increased at 7 DIV, and declined at 17 DIV and 21 DIV respectively (p < 0.05). That is, a trend of high GluR1 with much lower GluR2 expression on the surface membrane of epileptiform discharges experienced neurons over time in culture was presented. These findings in an in vitro model of early-life seizure may inform rodent models of epilepsy, as well as the cellular mechanism involved in epilepsy-associated brain dysfunction.     

磷酸钙人工骨(CPC)在颈前路椎间融合的临床应用

目的探讨磷酸钙人工骨(CPC)在颈椎前路椎间融合手术中的应用效果。方法2001年4月至2003年10月颈前路手术中应用磷酸钙人工骨栓椎间融合结合钛钢板固定治疗颈椎病17例,颈椎间盘突出症5例,颈椎外伤脱位2例,共24例35个节段。采用JOA评分评价神经功能,X线片判定融合效果。结果随访18±6.5个月,术后无感染,无过敏或毒性反应。JOA评分由术前9.28±2.15分增加到14.65±2.18分(P<0.001)。术后X线片未见CPC骨栓塌陷或移位,钛板和螺钉无松动及折断。术后16.5±6.8个月均获得椎间融合。结论颈椎前路椎间融合手术应用磷酸钙人工骨替代自体骨,经济、安全、简便、效果可靠。     

An open, randomized, comparative study of clarithromycin and erythromycin in the treatment of children with community-acquired pneumonia.

BACKGROUND AND PURPOSE: This study aimed to evaluate the efficacy and safety of clarithromycin and erythromycin in the treatment of community-acquired pneumonia in children. METHODS: Children with community-acquired pneumonia were randomly assigned to receive 10-day regimens of either clarithromycin 15 mg/kg/day, twice a day, or erythromycin 30-50 mg/kg/day, four times daily. RESULTS: A total of 97 children entered this study, including 26 with Mycoplasma pneumoniae infection, 15 with Chlamydia pneumoniae infection, and 6 with mixed mycoplasma and chlamydia infections. Fifty and 47 children received clarithromycin and erythromycin treatment, respectively. Three children withdrew from the study because the identified pathogens were resistant to the study drugs. All 47 children with mycoplasma or chlamydia infection were cured clinically. Delayed defervescence, defined as a fever lasting for more than 72 h after treatment, was observed in 4 of 22 clarithromycin-treated children (18%) and in 3 of 15 erythromycin-treated children (20%) [p>0.05]. Gastrointestinal side effects, including vomiting, abdominal pain and diarrhea, were observed in 3 of 50 children (6%) receiving clarithromycin and in 11 of 49 children (22%) receiving erythromycin (p=0.039). Excluding children with abnormal pretreatment liver function, abnormal liver function after treatment was observed in only one child, treated with erythromycin. Post-treatment eosinophil and platelet counts were significantly elevated after treatment in both groups. CONCLUSIONS: Clarithromycin showed efficacy equivalent to erythromycin for the treatment of mycoplasma or chlamydia pneumonia in children. However, the tolerability of clarithromycin was superior to that of erythromycin.     

cDNA基因芯片数据分析软件的研发进展

数据分析与挖掘是基因芯片研究的关键和难点,而软件是数据分析方法实现的主要手段。我们从以下几个方面对cDNA基因芯片分析软件进行了综述。首先介绍了芯片数据的获取及分析的软件,然后概述了不同统计软件在芯片数据分析中的应用,并详细介绍几种常用的芯片数据分析软件,最后简述了基因网络分析及数据挖掘方面的软件。