219 research outputs found

    Dialectal variation in Swahili – Based on the data collected in Zanzibar

    Get PDF
    This study examines some lexical and morphosyntactic variation found among the Swahili varieties in Zanzibar, Tanzania. It has been reported that there are three varieties in the island, and the new data collected in the villages inside the island suggest that there is a need for closer investigation and finer categorization of the Zanzibar varieties. Furthermore, there has been little discussion about the relationship between the Standard variety and other varieties or variation in the use of these varieties. In this paper, we report on the use of these Zanzibar varieties, namely, the town variety, Kiunguja-Mjini, the Northern varieties Kichaani, Kikibeni, Kitumbatu-Gomani, Kinungwi and Kimatemwe, and the Southern varieties Kijambiani, Kipaje and Kimakunduchi at the level of the lexicon. In addition, we examine the varieties of the Northern province – Kichaani, Kikibeni, Kitumbatu-Gomani, Kinungwi, and those of the Southern province – Kijambiani, Kipaje at the level of the grammar. In this paper, we concentrate on tense/aspect, the copula sentence, relative clause, and imperative. Among the data on these languages, we investigate, in particular, the variation among these varieties on the one hand, and the variation between these varieties and Standard Swahili on the other

    EXPRESSION AND FUNCTION OF A NONGLYCOSYLATED MAJOR HISTOCOMPATIBILITY CLASS I ANTIGEN

    Full text link
    The major histocompatibility class I antigens, expressed in most somatic cells, have carbohydrate moieties. We constructed mutant mouse MHC class I genes in which codons for the N-linked glycosylation sites were replaced by those of other amino acids. L cell transformants expressing the nonglycosylated class I antigens allowed us to investigate biological roles of carbohydrates with the highest specificity possible. The nonglycosylated antigen was unchanged in its overall serological specificities, and was recognized by alloreactive cytotoxic T cells. Further, the antigen was capable of mediating cytotoxic activity of vesicular stomatitis virus-specific T cells. These studies indicate that carbohydrates are not essential for immunological function of the MHC class I antigens. Cell surface expression of the nonglycosylated antigen was markedly reduced as compared with the native antigen, which was not attributable to accelerated degradation or rapid shedding. We conclude that the primary role of carbohydrates of the class I antigens is to facilitate the intracellular transport of the nascent proteins to the plasma membrane. The possible involvement of carbohydrate-receptor interactions in this process is discussed

    Presynaptically Released Cbln1 Induces Dynamic Axonal Structural Changes by Interacting with GluD2 during Cerebellar Synapse Formation

    Get PDF
    SummaryDifferentiation of pre- and postsynaptic sites is coordinated by reciprocal interaction across synaptic clefts. At parallel fiber (PF)-Purkinje cell (PC) synapses, dendritic spines are autonomously formed without PF influence. However, little is known about how presynaptic structural changes are induced and how they lead to differentiation of mature synapses. Here, we show that Cbln1 released from PFs induces dynamic structural changes in PFs by a mechanism that depends on postsynaptic glutamate receptor delta2 (GluD2) and presynaptic neurexin (Nrx). Time-lapse imaging in organotypic culture and ultrastructural analyses in vivo revealed that Nrx-Cbln1-GluD2 signaling induces PF protrusions that often formed circular structures and encapsulated PC spines. Such structural changes in PFs were associated with the accumulation of synaptic vesicles and GluD2, leading to formation of mature synapses. Thus, PF protrusions triggered by Nrx-Cbln1-GluD2 signaling may promote bidirectional maturation of PF-PC synapses by a positive feedback mechanism

    Primary culture of adult rat liver cells. III. Hormonal effects on cytological and biochemical properties of primary cultured cells.

    Get PDF
    The effect of various hormones on cytological and biochemical properties of cultured hepatic cells were investigated in order to obtain long-term survival of the hepatocytes with adult liver functions in primary culture. Insulin supplementation of the culture medium enhanced the attachemnt efficiency of cells in primary culture without affecting either maintenance of morphological characters of epithelial cells or retention of liver-specific functions in cultured cells. A combination of dexamethasone and insulin was apparently effective in stimulating the formation of a monolayer of polygonal cells with granular cytoplasm and in maintenance of liver-specific functions for relatively longer periods. Supplementation with either dexamethasone or hydrocortisone alone enhanced tyrosine aminotransferase activities in cultured cells for at least 4 days postinoculation. These steroid hormones also allowed growth of small epithelial cells with clear cytoplasm and maintenance of increased albumin production for 8 days after inoculation. The roles of these hormones in the primary culture of isolated hepatic cells are discussed in the present paper.</p

    A comparison of nephrotoxicity between patients with a solitary-functioning kidney and those with bilateral-functioning kidneys in cisplatin-based chemotherapy for advanced urothelial carcinoma: a Japanese retrospective multi-institutional study

    Get PDF
    BackgroundTo compare the prevalence of nephrotoxicity between patients with a solitary-functioning kidney versus those with bilateral-functioning kidneys during the administration of cisplatin-based chemotherapy for advanced urothelial carcinoma.MethodsWe retrospectively analyzed 244 advanced urothelial carcinoma patients treated with cisplatin-based chemotherapy between 2004 and 2010 at 17 institutes in Japan. The 24 h creatinine clearance, Cockcroft–Gault formula, and estimated glomerular filtration rate equation (eGFR), were compared before all chemotherapies. The urinary tract function status was determined based on the data of nephroureterectomy, hydronephrosis, and relief of upper urinary tract obstruction. A total of 244 patients were divided into four groups according to their urinary tract functioning status and eGFR results, including bilateral-functioning kidneys with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 83, 34.0%); a solitary-functioning kidney with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 36, 14.8%); bilateral-functioning kidneys with pretreatment eGFR  10% and 30% from baseline in the post-third-course of chemotherapy was significantly higher in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney, among patients with pretreatment eGFR  20% from baseline were significantly higher in patients with bilateral-functioning kidneys than those with a solitary-functioning kidney among patients with pretreatment eGFR < 60 mL/min/1.73 m2 (p = 0.034), whereas no significant difference was observed among patients with pretreatment eGFR ≥60 mL/min/1.73 m2.ConclusionsThe results suggest that cisplatin-based chemotherapy may have more nephrotoxicity in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney

    Neuroimaging in autism spectrum disorders : 1H-MRS and NIRS study

    Get PDF
    Using proton magnetic resonance spectroscopy (1H-MRS), we measured chemical metabolites in the left amygdala and the bilateral orbito-frontal cortex (OFC) in children with autism spectrum disorders (ASD). The concentrations of N-acetylaspartate (NAA) in these regions of ASD were significantly decreased compared to those in the control group. In the autistic patients, the NAA concentrations in these regions correlated with their social quotient. These findings suggest the presence of neuronal dysfunction in the amygdala and OFC in ASD. Dysfunction in the amygdala and OFCmay contribute to the pathogenesis of ASD.We performed a near-infrared spectroscopy (NIRS) study to evaluate the mirror neuron system in children with ASD. The concentrations of oxygenated hemoglobin (oxy-Hb) were measured with frontal probes using a 34-channel NIRS machine while the subjects imitated emotional facial expressions. The increments in the concentration of oxy-Hb in the pars opercularis of the inferior frontal gyrus in autistic subjects were significantly lower than those in the controls. However, the concentrations of oxy-Hb in this area were significantly elevated in autistic subjects after they were trained to imitate emotional facial expressions. The results suggest that mirror neurons could be activated by repeated imitation in children with ASD
    corecore