Differential anatomical and cellular patterns of connexin43 expression during postnatal development of rat brain.

We have shown previously that connexin43 in the adult rat central nervous system (CNS) is predominantly localized at astrocytic gap junctions. Here we document immunohistochemically the emergence of connexin43-immunoreactive (connexin43-IR) structures and the regional patterns of connexin43 expression during postnatal maturation of the rat brain. On Western blots, connexin43 was detected in brain samples at postnatal day (P) 5, the earliest age studied. Immunohistochemically, most brain regions displayed a characteristic sequence of transient immunoreactive profiles that ultimately gave rise to the uneven distribution of the protein seen in adults. Generally, brains at P1-P5 exhibited long, fibrous connexin43-IR elements which were identified as radial glial cells. This fibrous immunostaining was considerably diminished at P5 and was replaced by short immunoreactive processes which predominated up to P10. These processes had a stellate appearance, emanated from partially stained astrocytic cell bodies and were heterogeneously distributed throughout the developing brain. By P15, there occurred only punctate immunolabelling similar to that seen in adult brain. Some brain regions including the amygdaloid complex, septohypothalamic nucleus, preoptic hypothalamus, zona incerta, ependyma and subfornical organ were exceptional in that they displayed adult immunostaining patterns at early postnatal ages suggesting a precocious maturation of gap junctions in these areas. We conclude that the highly heterogeneous distribution of connexin43-immunoreactivity among defined nuclear structures in adult brain does not reflect an antecedent requirement for connexin43 in early brain morphogenesis, but rather is related to the development of neuronal activity, the establishment of functional circuitry and the contribution of astrocytic gap junctions to glial metabolic coupling and potassium spatial buffering in the mature CNS.     

Immunohistochemical detection of transforming growth factor-beta 1 in fibrotic liver diseases.

Transforming growth factor-beta 1 was localized by means of immunohistochemical reaction in liver biopsy specimens taken from patients having different chronic liver diseases with extending fibrosis. Two polyclonal antibodies that were produced in rabbits were directed against the amino terminal of transforming growth factor-beta 1. Staining by anti-CC(1-30) was primarily extracellular and located in the portal and periportal fibrotic areas of all seven cases with chronic active hepatitis. No staining was noted in the four chronic persistent cases studied. A strong reaction was seen with the antibody in nine of the ten cirrhotic samples, whereas it was negative in one inactive cirrhosis case and in all five cases with normal liver histological findings. No positive staining could be detected by the anti-LC(1-30) in any of the liver tissues. Detection of transforming growth factor-beta 1 in active liver diseases at the site of fibrosis suggests that transforming growth factor-beta 1 might have a role in the process and progression of fibrosis during the development of the disease.     

Small interfering RNA inhibits SARS-CoV nucleocapsid gene expression in cultured cells and mouse muscles

SARS-CoV isa newly identified coronavirus that causes severe acute respiratory syndrome （SARS）. Currently, there is no effective method available for prophylaxis and treatment of SARS-CoVinfections. In the present study, the influence of small interfering RNA （siRNA） on SARS-CoV nucleocapsid （N） protein expression was detected in cultured cells and mouse muscles. Four siRNA expression cassettes driven by mouse U6 promoter targeting SARS-CoV N gene were prepared, and their inhibitory effects on expression of N and enhanced green fluorescence protein （EGFP） fusion protein were observed.     

An evaluation of the effect of eicosapentaenoic acid in the diet on macrophage PGE production and lymphocyte proliferation in a burned guinea pig model

This study was undertaken to determine if dietary eicosapentaenoic acid (EPA) could affect the production of PGE (PGE₂ and/or PGE₃) by splenic macrophages and the mitogen-induced proliferation of splenic lymphocytes.Guinea pigs received a 30% total body surface area burn following installation of gastrostomy feeding tubes. All animals received identical diets except for the lipid component which equalled 10% of total energy. The control diet contained only linoleic acid (LA) as the lipid component. The experimental diets contained increasing amounts of EPA. Fourteen days postburn, the animals were sacrificed and splenic lymphocytes and macrophages were obtained and cultured for lymphocyte proliferation with and without mitogen stimulation and for PGE₂ synthesis in response to bacterial lipopolysaccharide (LPS), respectively.Increasing amounts of EPA in the diets had no statistically significant effect on the total production of PGE (PGE₂ and/or PGE₃) by macrophages stimulated with LPS, however, when 100% EPA was used as the lipid component, the production of PGE₂ was increased. Also, increasing amounts of EPA in the diet did not affect lymphocyte proliferation following stimulation of the cells with various mitogens, although at an EPA:LA ratio of 75:25%, a significant increase in proliferation of unstimulated but not stimulated lymphocytes was observed. However, at a 100:0 ratio of EPA:LA, lymphocyte proliferation was back down to the control level. This study shows that dietary EPA in high concentrations may have some complex interaction with the immune system at least in the animal under the stress of a burn.     

Ovulation by repeated human chorionic gonadotrophin in 'empty follicle syndrome' yields a twin clinical pregnancy

This case illustrates the possibility of obtaining oocytes that fertilize and cleave normally after the administration of a second ovulatory dose of human chorionic gonadotrophin (HCG) in a case of 'empty follicle syndrome'. The present patient underwent ovarian stimulation with gonadotrophin-releasing hormone analogue (GnRHa)/menotropin for intracytoplasmic sperm injection (ICSI). After the failure of the first oocyte retrieval, a second dose of HCG was administered to trigger ovulation. A total of 13 oocytes was retrieved during the second procedure and 11 good quality embryos were obtained (fertilization and cleavage rates of 92 and 91% respectively). No pregnancy was achieved after the replacement of three embryos. In a subsequent cycle stimulated with clomiphene citrate, three frozen- thawed embryos were replaced and a twin pregnancy was achieved. The patient delivered two healthy babies at term.      

Forme fruste of Hunter's disease

We report on a 19-year-old girl with hepatosplenomegaly and possible hematological disease. We suspected Gaucher's disease on account of histological and biochemical evidence found in specimens from the liver, spleen, and bone marrow. 18 months later, pebbled skin developed on her neck and upper back. Histological examination revealed large amounts of mucous material between the collagen bundles deep in the dermis, which proved to be dermatan sulfate. The clinical and histological symptoms are characteristic for Hunter's disease.     

黑柴胡中新三萜皂甙的结构鉴定

从黑柴胡(Bupleurum smithii Wolff)根中分离出10个化合物,均为首次由该植物中获得。其中二个新三萜皂甙,即柴胡皂甙k和l(saikosaponin k and l),其结构经紫外、红外、核磁共振氢谱,碳谱和质谱等波谱测定和解析,分别确定为3β,16β,23,28-四羟基齐墩果烷-11,13(18)-二烯-3-O-β-D-吡喃木糖基-(1→2)-β-D-吡喃葡萄糖基-(1→3)-β-D-吡喃呋糖甙和3β,16α,23,28,30-五羟基齐墩果烷-11,13(18)-二烯-3-O-β-D-吡喃葡萄糖基-(1→3)-β-D-吡喃呋糖甙。     

Human herpesvirus 6 variant a infects human term syncytiotrophoblasts in vitro and induces replication of human immunodeficiency virus type 1 in dually infected cells

Human herpesvirus 6 (HHV-6) and human immunodeficiency virus type 1 (HIV-1) may interact during transplacental transmission of HIV-1. The placental syncytiotrophoblast layer serves as the first line of defense of the fetus against viruses. Patterns of replication of HHV-6 variant A (HHV-6A) and HIV-1 were analyzed in singly and dually infected human term syncytiotrophoblast cells cultured in vitro. For this purpose, the GS strain of HHV-6A and the Ba-L and IIIB strains of HIV-1 were used. HHV-6A replication was restricted at the level of early gene products in singly infected syncytiotrophoblasts, whereas no viral protein expression was found in cells infected with HIV-1 alone. Coinfection of syncytiotrophoblast cells with HHV-6A and HIV-1 resulted in production of infectious HIV-1. In contrast, no enhancement of HHV-6A expression was observed in cell cultures infected with both viruses. Uninfected syncytiotrophoblast cells were found to express CXCR4 and CCR3 but not CD4 or CCR5 receptors. Infection of syncytiotrophoblasts with HHV-6A did not induce CD4 expression and had no influence on chemokine receptor expression. Activation of HIV-1 from latency in coinfected cells was mediated by the immediate-early (IE)-A and IE-B gene products of HHV-6A. Open reading frames U86 and U89 of the IE-A region were able to activate HIV-1 replication in a synergistic manner. The data suggest that in vivo double infection of syncytiotrophoblast cells with HHV-6A and HIV-1 could contribute to the transplacental transmission of HIV-1 but not HHV-6A.     

Feeding microstructure in diet-induced obesity susceptible versus resistant rats: central effects of urocortin 2

With one billion people overweight worldwide, the need to identify risk factors and treatments for obesity is urgent. The present study determined whether rats genetically prone to diet-induced obesity (DIO) show preexisting differences in meal microstructure and are sensitive to central anorectic effects of corticotropin-releasing factor type 2 (CRF₂) receptor stimulation. Male, selectively bred DIO rats and their diet resistant (DR) counterparts ( n = 9/genotype) were weaned onto low-fat chow and compared as young adults for spontaneous or intracerebroventricular urocortin 2 administration-induced (0, 0.3, 1, 3 μg) differences in ingestion. DIO rats were hyperphagic selectively at the dark cycle onset, showing shorter latencies to initiate feeding, faster returns to eating following meal completion, and a lower satiety ratio than DR rats. At other times, DIO rats had briefer postmeal intervals, but ate smaller and briefer meals, resulting in normal intake. DIO rats also ate faster than DR rats. Urocortin 2 was less potent in DIO rats, ineffective at the 0.3 μg dose, but produced CRF₂ antagonist-reversible anorexia at higher doses. Though heavier, chow-maintained DIO rats were proportionately as or more lean than DR rats. Thus, DIO rats showed signs of a preexisting, heritable deficit in the maintenance of postmeal satiety and a reduced sensitivity to anorectic CRF₂ agonist stimulation. The meal patterns of DIO rats temporally resemble human 'snacking' behaviour, which predicts adult obesity. Because central CRF₂ stimulation retains full anorectic efficacy at higher doses in the DIO model, manipulating this neuropeptidergic system might yield new therapeutic approaches for diet-induced obesity.