Highly Pathogenic Avian Influenza (H5N1) Virus in Feathers.

H5N1 highly pathogenic avian influenza (HPAI) virus causes high mortality of infected birds, with infection in multiple organs, including in feathers. Feathers have been proposed as samples for diagnosis of HPAI infection in birds, and this study is part of a broader investigation validating the use of feathers for diagnostic purposes. To understand and characterize the morphological basis for feather infection, sections from 7 different skin tracts of ducks and chickens infected with 3 different clades of H5N1 HPAI virus from Indonesia and Vietnam were examined histologically. Results showed that in ducks, lesions and viral antigen were mainly detected in the epidermis of feathers and follicles, whereas in chickens, they were mostly found in the dermis of these structures. Abundant viral antigen was found in nearly all the feathers examined from chickens, and there was no apparent difference between virus isolates or skin tracts in the proportion of feathers that were antigen positive. By immunohistochemistry, the majority of feathers from most skin tracts from ducks infected with a Vietnamese H5N1 HPAI virus contained abundant levels of viral antigen, while few feathers were antigen positive from ducks infected with 2 Indonesian viruses. These results support and inform the use of feathers for diagnostic detection of H5N1 HPAI virus in birds.

Amorphous silicene-a view from molecular dynamics simulation.

Models of amorphous silicene (a-silicene) containing 10(4) atoms are obtained by cooling from the melt via molecular dynamics (MD) simulation. The evolution of various kinds of structural and thermodynamic behavior in models upon cooling from the melt is found, including total energy, radial distribution function (RDF), interatomic distance, coordination number, and ring and bond-angle distributions. We also show the buckling distribution and a 2D visualization of the atomic configurations. The diffraction pattern shows that a glass state is indeed formed in the system. The glass transition temperature of 2D silicon ([Formula: see text] K) has a reasonable value compared to that of its 3D counterpart. Calculations show that although most atoms in a-silicene obtained at 300 K have a three-fold coordination and mainly evolve into six-fold rings, a-silicene also contains various structural defects including those not found in crystalline silicene (c-silicene) such as adatoms, clusters of small-membered rings, large-membered rings and local linear defects. The concentration of defects in a-silicene is much higher than that of the crystalline version. We find that buckling is not unique for all the atoms in the model. The strong distorted structure of a-silicene compared to that of the crystalline version may lead to physico-chemical properties, including the possibility of opening the band gap in the former compared to the zero band gap of the latter. Note that due to the fixed length being equal to buckling of 0.44 Å in the [Formula: see text] direction with the elastic reflection behavior boundary, our models are relevant for a-silicene formed in confinement between two planar simple hard walls.

Recent avian influenza virus A/H5N1 evolution in vaccinated and unvaccinated poultry from farms in Southern Vietnam, January-March 2010.

We report 15 new avian influenza virus A/H5N1 haemagglutinin (HA) sequences sampled from visibly sick domestic poultry in southern Vietnam, between 1 January 2010 and 6 March 2010. These HA sequences form a new sub-clade of the clade 1 H5N1 viruses that have been circulating in Vietnam since 2003/2004. The viruses are characterized by a change from isoleucine to valine at position 514 (I514V) and are 1.8% divergent at the nucleotide level from HA sequences sampled in Vietnam in 2007. Five new amino acid changes were observed at previously identified antigenic sites, and three were located within structural elements of the receptor-binding domain. One new mutation removed a potential N-linked glycosylation site, and a methionine insertion was observed in one virus at the polybasic cleavage site. Five of these viruses were sampled from farms where poultry were vaccinated against H5N1, but there was no association between observed amino acid changes and flock vaccination status. Despite the current lack of evidence for antigenic drift or immune escape in Vietnamese H5N1 viruses, continued surveillance remains a high priority.

Rhizobacterially induced protection of watermelon against Didymella bryoniae.

AIMS: To identify rhizobacteria from the Mekong Delta of Vietnam, which can systemically protect watermelon against Didymella bryoniae and elucidate the mechanisms involved in the protection conferred by isolate Pseudomonas aeruginosa 23(1-1). METHODS AND RESULTS: Bacteria were isolated from watermelon roots and their antagonistic ability tested in vitro. Of 190 strains, 68 were able to inhibit D. bryoniae by production of antibiotics. Four strains were able to reduce foliar infection by D. bryoniae when applied to watermelon seeds before sowing. Strain Ps. aeruginosa 23(1-1) was chosen for investigations of the mechanisms involved in protection and ability to control disease under field conditions. In the field, the bacterium was able to significantly reduce disease in two consecutive seasons and increase yield. Furthermore, it colonized watermelon plants endophytically, with higher numbers in plants infected by D. bryoniae than in noninoculated plants. To elucidate the mechanisms involved in protection, the infection biology of the pathogen was studied in bacterially treated and control plants. Pseudomonas aeruginosa 23(1-1) treatment inhibited pathogen penetration and this was associated with hydrogen peroxide accumulation, increased peroxidase activity and occurrence of new peroxidase isoforms, thus indicating that resistance was induced. CONCLUSIONS: The endophytic bacterium Ps. aeruginosa 23(1-1) can control D. bryoniae in watermelon by antibiosis and induced resistance under greenhouse and field conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings suggest that rhizobacteria from native soils in Vietnam can be used to control gummy stem blight of watermelon through various mechanisms including induction of resistance.

[Ascaris-induced acute pancreatitis]. / Ascaridiose biliopancréatique.

AIM OF THE STUDY: To indicate options in a surgical university team in Vietnam for treatment of ascaris-induced acute pancreatitis. PATIENTS AND METHODS: From January 1998 to April 2001, 33 patients (mean age 46 years) were admitted with a diagnosis of acute pancreatitis based on elevated serum amylase in 29 patients (88%), and elevated urinary amylase in all patients and a compatible clinical picture. The pancreatic ultrasonography was abnormal in 79% of cases. Biliary and pancreatic ultrasonography shown ascaris in 31 patients (94%). In other two patients ascaris was detected with duodenal endoscopy. RESULTS: In 24 patients, the worms from the duodenum and/or across the ampullary orifice was trapped and withdrawn during duodenoscopy and failed in three patients. Nine patients were operated on, three after failure of endoscopic treatment, five for lithiasis of the common bile duct associated to the ascariasis, and one for necrotic pancreatitis. Seven patients operated on underwent a choledocotomy with a T-tube drainage, two patients underwent a left pancreatectomy to withdraw the ascaris, and one patient a resection of pancreatic necrosis. All patients recovered without complications except the patient with a necrotic pancreatitis who developed a pancreatic fistula for 23 days. Mean discharge times were 5.6 days after endoscopic treatment and 12.2 days after surgery. Effective antihelminthic therapy was administered in all patients. CONCLUSION: Endoscopic treatment was effective in 24 out of 33 patients. Surgery was indicated for failures of endoscopic treatment, association of ascariasis and common bile duct stones, migration of ascaris in intra pancreatic duct, and pancreatic necrosis.

Brain tumours in Ho Chi Minh City.

A series of 65 intracranial tumours operated on, and followed by, the same surgical team during 7 years is presented as a retrospective analysis (1987-1994). Among these patients, only 38 had a diagnosis based upon computed tomography (CT) scan because it was not until 1991 that the first CT scanner was set up in Ho Chi Minh City. Many patients were drowsy or comatose prior to operation due to lack of specialists' intervention or tardy diagnosis and evacuation from remote provincial hospitals. All operations were satisfactory despite the lack of many essential instruments. The histological diagnosis followed the classification proposed by Zulch KJ.(1) Intratumoural calcification has in no case been seen on X-rays or on histological specimens. Operative mortality rate was nil. Although not all the patients with malignant tumours could be followed up, the data available concerning their survival time and the quality of life seems similar to that observed in other reports.

[A new conception of the physiology of amniotic circulation]. / Conception nouvelle sur la physiologic de la circulation amniotique.

A histological study of the ovular membranes made by the authors showed that they represent an organ closely resembling the placenta and led them to believe that the metabolic processes that regulate the amniotic fluid occur in all the membranes and more especially in the region of the cytotrophoblast in the chorion that delimits the amniotic cavity. In the same way that the concept of a placental barrier has been abandoned in relation to the materno-fetal exchanges in the intervillous space, a concept that regarded the exchanges as simple diffusion across a theoretical membrane, the authors think that the concept of diffusion, simple transudation, across a little differentiated membrane such as the amnion must be abandoned in relation to the formation of the amniotic fluid. The placenta and the membranes form a whole in which the trophoblast plays a fundamental role in the feto-maternal exchanges in both the intervillous space and the amniotic cavity. This oneness makes possible an explanation of the physiopathology of both quantitive and qualitative regulatory disorders of the amniotic fluid.

[The interest of crossed anchoring of the uterosacral ligaments to the pubic arch following vaginal hysterectomy for genital prolapse]. / Intérêt de la fixation croisée des ligaments utéro-sacrés à l'ogive pubienne après hystérectomie vaginale pour prolapsus génital.

Vaginal hysterectomy followed by anchorage of crossed uterosacral ligaments to the pubic arch appears as an interesting method in premenopausal or menopausal women suffering from advanced protruding genital prolapse and having uterosacral ligaments that have still retained some functional value. With this method, by a simple crossing and reestablishment of strain of the uterosacral ligaments, the pelvis is provided with a highly valuable support, while the vagina is given a normal length. From July, 1962, until December, 1968, a total of 160 genital prolapses have been operated on with this procedure. Overall, early and late results seem excellent.

[Cytological diagnosis of the term of pregnancy using urethrocytogram]. / Le diagnostic cytologique du terme de la grossesse par l'uréthrocytogramme.

The advantages and drawbacks of urethrocytogram in the course of pregnancy, as compared with vaginal smear to determine how near the term is, have been studied by the authors. They have come to the conclusion that urethrocytogram was an easy to perform examination requiring no highly special equipment, easy to read and capable of giving an immediate answer when the vaginal smear cannot be interpreted because If the existing inflammation, which occurs in one third of cases. Modifications of the urethrocytogram show a slight delay as compared with those shown by the vaginal smear.