WU polyomavirus detected in respiratory tract specimens from young children in Japan.

Polyomaviruses (PyV) WU and KI are reportedly associated with respiratory tract disease (RTD) worldwide but their incidence is unclear in Japan. In a 2 year prospective study, WU/KIPyV were detected in 48 (13.9%) and in five (1.4%) of 345 children hospitalized with lower RTD, respectively. The seasonal distribution was observed in spring and early summer. Other respiratory viruses were co-detected in 51% of PyV-positive patients, but eight (2.3%) of the WUPyV-positive patients were negative for other known pathogens.

Insertional mutation in the Golgb1 gene is associated with osteochondrodysplasia and systemic edema in the OCD rat.

Homozygous rats (ocd/ocd) of a mutant inbred strain, OCD (osteochondrodysplasia), show osteochondrodysplasia, systemic edema, cleft palate, protruding tongue, disproportionate dwarfism, and lethality immediately after birth. Their epiphyses show decreased levels of glycosaminoglycans and weak staining for extracellular matrix proteins. The epiphyseal chondrocytes have large vesicles and expanded endoplasmic reticulum and Golgi apparatus. These phenotypic features are inherited in an autosomal recessive manner, and the ocd locus responsible for these phenotypes has been mapped close to D11Mgh3 on rat chromosome 11. In the present study, we characterized the embryonic pathogenesis of ocd/ocd rats and identified the mutant gene. Subcutaneous edema in the dorsal portion was found at embryonic day (E) 16.5, and the other anomalies described above were apparent after E18.5 in ocd/ocd. Whole mount immunohistochemistry for Sox9 revealed that mesenchymal condensation was delayed in limb bud in ocd/ocd, and skeletal preparation showed that the progression of whole-body chondrogenesis was delayed in ocd/ocd. Histological and immunohistological analyses of the femur showed that cell proliferations of resting and proliferative zones of growth plate were significantly reduced in ocd/ocd embryos. Fine linkage mapping localized the ocd locus within 84kb of positions 65,584-65,668kb containing a part of Golgb1 gene on chromosome 11. Expression of Golgb1 mRNA was found in limb buds, somite derivatives and calvaria. Sequence analysis identified a 10-bp insertion in exon 13 of the Golgb1 gene in ocd/ocd rats. The Golgb1 gene encodes the COPI vesicle tethering factor, giantin. This insertion mutation causes a frame shift, and introduces a premature termination codon at codon 1082, leading to truncation of the C-terminal two thirds of giantin. By in-gel Western analysis using anti-giantin antibody that recognizes an epitope within 200 aa of the C-terminus, the expression of giantin was not detected in ocd/ocd embryos. As the C-terminal region of giantin is required for localization to the Golgi apparatus, these results strongly suggested that giantin is functionally defective in ocd/ocd rats. Therefore, we concluded that mutation of the Golgb1 gene is responsible for the phenotypic characteristics including osteochondrodysplasia of ocd/ocd, and that giantin plays a pivotal role in multiple aspects of chondrogenesis.

Distinctive clinical features of human bocavirus in children younger than 2 years.

BACKGROUND AND OBJECTIVE: Clinical characteristics of human bocavirus (HBoV) infection have been studied worldwide, but their importance of those characteristics remains unknown. We investigated distinctive clinical features of HBoV-positive children with lower respiratory tract infection (LRTI). METHODS AND RESULTS: During April 2007-July 2009, for 402 hospitalized children younger than 2 years with LRTI, we prospectively examined virus genomes in nasopharyngeal swabs for HBoV, respiratory syncytial virus (RSV), rhinovirus, metapneumovirus, parainfluenzavirus, and adenovirus. The HBoV genomes were identified in 34 patients (8.5%). Clinical and laboratory data of HBoV-positive and other virus/bacteria-negative patients (n = 18) were analyzed and compared with data of RSV-single positive patients (n = 99). The seasonal distribution of HBoV exhibits a concentration of cases during March-September, with most RSV cases occurring during winter in Japan. The minimum age of HBoV-positive patients was 5 months, although 44 patients (44%) with RSV were younger than 6 months. The main clinical features were respiratory distress and hypoxia. Hypoxia advances within 3 days after onset. The mean oxygen saturation on arrival was 92.8%, which was significantly lower than that in patients with RSV (p < 0.001). White blood cell counts were similar among groups. However, the percentage of neutrophils in white blood cells were significantly higher in HBoV-positive patients (62 vs. 45%, p < 0.001). Their prognoses were good. Their hospital stays were 6.6 days. CONCLUSIONS: HBoV-single positive patients show several clinical characteristics, such as seasonality, age, hypoxia, and neutrophilia, which differ from those with RSV infection.