Hemagglutinin activity of two distinct genogroups of feline and canine rotavirus strains

Summary Genomes of hemagglutinating strains of feline and canine rotaviruses, were much more closely related to each other than to non-hemagglutinating strains. The Cat2 feline rotavirus appears to derive from reassortment between hemagglutinating and non-hemagglutinating strains.     

A comparison of prosthetic materials used to repair abdominal wall defects

Large abdominal wall defects may require a prosthesis for closure. The aim of our study was to identify the best material for abdominoplasty in pediatric patients. One hundred twenty-eight Wistar KY strain male rats (3 weeks old) were used. All animals underwent celiotomy via a midline skin incision. They were divided into seven groups as follows: the animals in groups 1 through 6 underwent full-thickness abdominal wall excision 3 cm in diameter. The animals in group 1 underwent primary closure. In groups 2 through 6 the defect was closed with prosthetic material. In Group 7, a sham operation was performed. Daily weights were measured. The animals were killed after 3 and 9 weeks. Adhesion scores were assigned for each group. Vicryl mesh resulted in the fewest adhesions and had no effect on weight gain in the developing rats. Accepted: 11 June 1997     

Effect of heparin on pulmonary fibroblasts and vascular cells.

BACKGROUND: There is a large increase in mast cell numbers in fibrotic lung tissue, suggesting that mast cells may play a part in the pathogenesis of pulmonary fibrosis. Glycosaminoglycans, such as heparan sulphate, that are structurally related to heparin (a mast cell product) are part of the extracellular matrix and known to regulate cell growth. Basic fibroblast growth factor is a heparin binding growth factor produced by endothelial cells. METHODS: A study was carried out to examine the effect of heparin, basic fibroblast growth factor, and mast cell products on the proliferation of normal human lung fibroblasts and the effect of adding heparin on the proliferation of lung fibroblasts and pulmonary vascular cells incubated with basic fibroblast growth factor. RESULTS: Heparin at low concentration (0.03, 0.3-1.0 micrograms/ml) stimulated the proliferation of normal human lung fibroblasts in culture whereas a higher concentration (100 micrograms/ml) had an inhibitory effect. Mast cell products also stimulated the proliferation of fibroblasts, and the effect was decreased by pretreatment with heparinase or protamine. Heparin enhanced the growth of both fibroblasts and pulmonary vascular cells induced by low concentrations of basic fibroblast growth factor. CONCLUSIONS: Mast cells in fibrotic lung tissue may regulate fibroblast proliferation by releasing heparin. These results suggest that endothelial cells may interact with mast cells and modulate fibroblast growth by release of basic fibroblast growth factor.     

Molecular identification of a novel G1 VP7 gene carried by a human rotavirus with a super-short RNA pattern

AU19 is a human rotavirus strain carrying a G1P2C[6] specificity and a super-short RNA pattern. Neutralization assay revealed an asymmetric cross neutralization between AU19 and Wa, a representative G1 rotavirus strain, and it is noteworthy that AU19 was neutralized poorly by anti-Wa hyper-immune serum. In the phylogenetic tree the VP7 gene of AU19 formed a lineage different from the established lineages of known human G1 rotaviruses. A signature code MFTKLLTAA was noted for AU19 lineage. These results provide evidences that the VP7 gene of AU19 represents a novel G1 lineage.     

Repeated circulation over 6 years of intergenogroup mono-reassortant G2P[4] rotavirus strains with genotype N1 of the NSP2 gene

Human rotavirus A, a major cause of acute diarrhoea in infants and young children worldwide, contains the genome of 11 segments of double-stranded RNA, which is grouped into three major genotype constellations: the Wa genogroup (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1), the DS-1 genogroup (G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2), and the AU-1 genogroup (G3-P[9]-I3-R3-C3-M3-A3-N3-T3-E3-H3). Recently, a G2P[4] strain detected in Kenya in 1982 was reported to be a nonstructural protein 2 (NSP2) gene mono-reassortant between the Wa and DS-1 genogroups. While NSP2 induces heterotypic antibody responses in children, thereby being the likely target of immune selective pressure, it was not known how frequently these NSP2 mono-reassortants circulated among children. In a previous 10 year epidemiological study, out of 100 G2P[4] rotavirus specimens that were typed into 22 distinct electropherotypes (i.e., strains), RNA-RNA hybridization identified that 12 strains were mono-reassortants involving either the NSP2 or the NSP3 gene. The aim of this study was therefore to determine the nucleotide sequences of all 11 genes of the representative mono-reassortant strain (AU605) and the sequences of the reassorted genes of the other mono-reassortant strains. The genome constellation of AU605 was G2-P[4]-I2-R2-C2-M2-A2-N1-T2-E2-H2, indicating that it was a mono-reassortant strain carrying a Wa-like NSP2 genotype on the DS-1 genogroup background. The reassorted gene of the other 11 strains also had the genotype N1 in the NSP2 gene. Given that electrophoretically-identical rotaviruses represent a single strain, the 12 NSP2 mono-reassortants detected in six rotavirus seasons accounted for 36% (36 of 100) of G2P[4] rotavirus specimens in the 10 year collection. The circulation of NSP2 mono-reassortant strains was observed in epidemic seasons when the G2P[4] genotype was not dominant. Taken together with their repeated occurrence at higher-than-expected frequencies, the identification of NSP2 mono-reassortant G2P[4] strains suggests that such genome constellation may also be viable in nature, and that they circulated less rarely than generally believed.     

A case of desmoplastic malignant mesothelioma with elevated serum CYFRA 21-1]

A 70-year-old woman was admitted to our hospital for medical evaluation of a right side pleural effusion, which was pointed out at another hospital. Chest CT revealed a right pleural effusion with diffuse and irregular pleural thickening. Percutaneous pleural biopsy showed hypocellular collagenous tissue without malignant cells. Though she received antituberculosis therapy, the pleural thickening progressed and the serum CYFRA 21-1 level was elevated. Chest pain and dyspnea appeared, and she was readmitted. However, pneumonia was present as a complication, and she died. At autopsy, the right pleura was thickened and invasion of the lung and the chest wall was observed. Microscopic findings showed increased amounts of hyalinized collagen fibers forming a storiform pattern. At the tumor foci, atypical cells with distinct nucleoli were observed. Desmoplastic malignant mesothelioma, which is rarely reported in Japan, was diagnosed.     

Incidence and burden of rotavirus gastroenteritis in Japan, as estimated from a prospective sentinel hospital study

We assessed the burden of rotavirus infection-related disease, in terms of hospitalization and associated costs, at 3 sentinel hospitals in Akita prefecture, Japan. From January 2001 through December 2002, a total of 443 children <5 years of age were hospitalized for acute gastroenteritis. Of 422 stool specimens collected, 244 (58%) tested positive for rotavirus. Only 7.8% of the rotavirus disease-associated hospitalizations involved infants <6 months of age, whereas most cases of disease (39%) were reported in the second year of life, and 89% of cases had occurred by 36 months of age. The mean severity score for rotavirus gastroenteritis resulting in hospitalization was 16.5, according to the modified 20-point severity scoring system. The average associated direct medical cost was 136,000 yen (1236 US dollars) per case and was similar among the 3 hospitals. The estimated incidence of rotavirus disease-associated hospitalizations among children <5 years of age was 7.9-17.6 hospitalizations/1000 person-years, and the estimated cumulative incidence by 5 years of age was 6.6%. Thus, approximately 1 in 15 children will require hospitalization due to rotavirus diarrhea by their fifth year of life. In Japan, this would mean that 78,000 children <5 years of age would be hospitalized each year, resulting in a direct medical cost of 10 billion yen (96 US dollars million). The burden associated with rotavirus gastroenteritis in Japan is substantial and might be reduced through the introduction of vaccines.     

Augmented contractile response to endothelin and blunted endothelium-dependent relaxation in post-ischemic reperfused coronary arteries.

To elucidate the pathogenesis of the post-ischemic vascular injury in reperfused coronary arteries, the left anterior descending coronary artery (LAD) was occluded for 30 min or 60 min in 26 dogs. After 120 min of reperfusion, vascular strips were prepared from LAD and the left circumflex coronary artery (LCX) as control, and suspended in organ chambers containing Krebs-Henseleit solution and vascular reactivity was evaluated pharmacologically. In a separate experiment, LCX-strips from 12 dogs were subjected ex vivo to blood cell-free simulated ischemia by the substitution of perfusate to hypoxic, low pH and high K+ for 60 min and the following 60 min of reoxygenation. Vascular responses to various agents were compared prior to and after simulated ischemia. Vascular injury was also investigated histologically with electron microscopy. As the results; significantly blunted endothelium-dependent relaxations to acetylcholine (10(-6) M) and Ca-ionophore (A-23187: 10(-6) M) in LAD-strips compared to LCX were noticed (43.7 +/- 4.8 vs 61.6 +/- 7.3%, 22.7 +/- 5.2 vs 47.9 +/- 8.4% in % relaxation, respectively). Augmented contractile response selective to endothelin was also observed in reperfused vessels (LAD) compared to control vessels (10(-9) M: 105.4 +/- 19.5 vs 42.4 +/- 12.3% of 20 mM-KCl induced contraction, p less than 0.01). Electron microscopy revealed partial detachment and blebbing of endothelial cells in reperfused coronary arteries. Similar changes were also observed in the simulated ischemia and reoxygenation study, but the augmented response to endothelin was seen only when polymorphonuclear leukocytes (PMN) activated with phorbol myristate acetate were added. Our results suggest that endothelial injury does not essentially depend on PMN, but PMN promote augmented response to endothelin. These changes indicate that enhanced spasmogeneity is present in reperfused arteries, which may contribute to post-infarction angina and prolonged myocardial dysfunction after reperfusion.