Correction of the chemical composition effect on the activity measurement of gamma emitters in environmental samples at low energy.

If the sample and the calibration standard are identical in geometry and in density, many laboratories of radioactivity measurement using gamma spectrometry, do not proceed to the correction of the effect of the possible difference in chemical composition between them. Some laboratories proceed to the correction of this effect using the usual simple ratio between the self absorption factor of the sample and the calibration standard based on the linear attenuation coefficients obtained using transmission experiments. In this work we studied this question by conducting Monte Carlo simulation of several typical environmental samples with different chemical compositions. We found that at low energy (E < 100 keV), chemical composition effect must be corrected. We found also that its correction using the usual simple ratio between the self absorption coefficient of the sample and the calibration standard is not useful for that purpose.

Utilization of nano-cryptomelane for the removal of cobalt, cesium and lead ions from multicomponent system: Kinetic and equilibrium studies.

Nano-cryptomelane was prepared and characterized using SEM with mapping, HRTEM, FT-IR spectra, thermal analysis and surface area. The diameter distribution of nano-cryptomelane was found to be 4-6 nm. Sorption performance of the prepared material was studied for the removal of Co2+, Cs+ and Pb2+ from a multi-system solution of equal molar ratio, 1:1:1. The sorption capacity of nano-cryptomelane was found to be 179.6, 442.6 and 716.9 mg/g for Co2+, Cs+ and Pb2+, respectively. The kinetic studies revealed that the sorption process obeys non-linear pseudo-second-order model and is controlled by an intra-particle diffusion mechanism. The equilibrium isotherm investigations outlined that the extended Langmuir isotherm model fits the data reasonably well and it is more applicable than Freundlich multicomponent sorption isotherm. The value of diffusion coefficient for the three metal ions is in the order 10-17 m2/s which indicates the chemisorption nature of the process. The desorption percentage attains the maximum value (98.13%, 97.29 and 97.04 for lead, cesium and cobalt ions, respectively) using 0.7 mol/L of HNO3. This revealed that nano-cryptomelane can be regenerated and reused for farther sorption of Pb2+, Cs+ and Co2+ from wastewater.

Nigella sativa oil and thymoquinone ameliorate albuminuria and renal extracellular matrix accumulation in the experimental diabetic rats.

OBJECTIVE: Increasing evidence suggests that Nigella sativa oil (NSO) and its principal bioactive constituents, thymoquinone (TQ), exhibit antioxidant, antihyperglycemic and renoprotective effects in streptozotocin (STZ)-induced diabetes in rats. However, the potential molecular mechanisms by which NSO and TQ may exert their actions in the diabetic kidney are still poorly characterized. This study was designed to investigate the effect of NSO and TQ treatment on the albuminuria, podocyte injury and the complex systems controlling the extracellular matrix proteins accumulation and angiogenesis in the STZ-induced model of diabetic nephropathy. MATERIALS AND METHODS: Adult female Wistar rats were divided into four experimental groups (control, untreated STZ-diabetic, and NSO or TQ treated STZ-diabetic rats). The treated rats received 2 mL/kg NSO or 50 mg/kg TQ via oral gavage once a day for 10 weeks. RESULTS: The results showed that the albuminuria and the kidney weight/body weight ratio were increased in the diabetic rats compared with the control animals and they were significantly ameliorated by the treatment with NSO or TQ. The real-time PCR showed that the NSO and TQ treatment prevented diabetes-induced downregulation of mRNA expression of the podocyte-specific marker (podocin) as well as the mRNA overexpressions of collagen IV, transforming growth factor-ß1 (TGF-ß1) and vascular endothelial growth factor-A (VEGF-A) in the diabetic kidney. These results were also confirmed by immunohistochemistry. CONCLUSIONS: NSO and TQ treatment decreased albuminuria in the experimental models of the diabetic nephropathy by the preservation of the podocyte function; along with the suppression of enhanced extracellular matrix gene expression through interfering with TGF-ß1 production and angiogenesis.

Epidemiological analysis, serological prevalence and genotypic analysis of foot-and-mouth disease in Nigeria 2008-2009.

The epidemiological situation of foot-and-mouth disease virus (FMDV) is uncertain in Nigeria, where the disease is endemic, and the majority of outbreaks are unreported. Control measures for FMD in Nigeria are not being implemented due to the absence of locally produced vaccines and an official ban on vaccine importation. This study summarizes the findings of a 3-year study aimed at quantifying the seroprevalence of FMD, its distribution in susceptible species and the genetic diversity of FMDV isolated from the Plateau State of Nigeria. A 29% FMD prevalence was estimated using 3ABC enzyme-linked immunosorbent assay (3ABC ELISA). Farms with suspected FMD nearby, with contact with wildlife, that used drugs or FMD vaccines or with >100 animals, and animals of large ruminant species and in pastures other than nomadic grazing were significantly (P < 0.05) associated with FMD. Antibodies against five FMDV serotypes, (A, O, SAT1, SAT2 and SAT3) were detected by the virus neutralization test (VNT) at various titres (<100->800) from all tested sera from most parts of the region. This is probably the first report of the presence of FMDV SAT3 in Nigeria. Further studies to investigate the potential probable presence and prevalence of SAT 3 virus in Nigeria are required. Tissue samples collected from clinical animals were positive for FMDV. Virus isolates were sequenced and confirmed as serotype A. All of the isolates showed marked genetic homogeneity with >99% genetic identity in the VP1 region and were most closely related to a previously described virus collected from Cameroon in 2000. This study provides knowledge on the epidemiological situation of FMD in Plateau State, Nigeria, and will probably help to develop effective control and preventive strategies for the disease in Nigeria and other countries in the West African subregion.

Foot-and-mouth disease in feral swine: susceptibility and transmission.

Experimental studies of foot-and-mouth disease (FMD) in feral swine are limited, and data for clinical manifestations and disease transmissibility are lacking. In this report, feral and domestic swine were experimentally infected with FMDV (A24-Cruzeiro), and susceptibility and virus transmission were studied. Feral swine were proved to be highly susceptible to A-24 Cruzeiro FMD virus by intradermal inoculation and by contact with infected domestic and feral swine. Typical clinical signs in feral swine included transient fever, lameness and vesicular lesions in the coronary bands, heel bulbs, tip of the tongue and snout. Domestic swine exhibited clinical signs of the disease within 24 h after contact with feral swine, whereas feral swine did not show clinical signs of FMD until 48 h after contact with infected domestic and feral swine. Clinical scores of feral and domestic swine were comparable. However, feral swine exhibited a higher tolerance for the disease, and their thicker, darker skin made vesicular lesions difficult to detect. Virus titration of oral swabs showed that both feral and domestic swine shed similar amounts of virus, with levels peaking between 2 to 4 dpi/dpc (days post-inoculation/days post-contact). FMDV RNA was intermittently detectable in the oral swabs by real-time RT-PCR of both feral and domestic swine between 1 and 8 dpi/dpc and in some instances until 14 dpi/12 dpc. Both feral and domestic swine seroconverted 6-8 dpi/dpc as measured by 3ABC antibody ELISA and VIAA assays. FMDV RNA levels in animal room air filters were similar in feral and domestic swine animal rooms, and were last detected at 22 dpi, while none were detectable at 28 or 35 dpi. The FMDV RNA persisted in domestic and feral swine tonsils up to 33-36 dpi/dpc, whereas virus isolation was negative. Results from this study will help understand the role feral swine may play in sustaining an FMD outbreak, and may be utilized in guiding surveillance, epidemiologic and economic models.

Pathogenicity and molecular characterization of emerging porcine reproductive and respiratory syndrome virus in Vietnam in 2007.

In 2007, Vietnam experienced swine disease outbreaks causing clinical signs similar to the 'porcine high fever disease' that occurred in China during 2006. Analysis of diagnostic samples from the disease outbreaks in Vietnam identified porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2). Additionally, Escherichia coli and Streptococcus equi subspecies zooepidemicus were cultured from lung and spleen, and Streptococcus suis from one spleen sample. Genetic characterization of the Vietnamese PRRSV isolates revealed that this virus belongs to the North American genotype (type 2) with a high nucleotide identity to the recently reported Chinese strains. Amino acid sequence in the nsp2 region revealed 95.7-99.4% identity to Chinese strain HUN4, 68-69% identity to strain VR-2332 and 58-59% identity to strain MN184. A partial deletion in the nsp2 gene was detected; however, this deletion did not appear to enhance the virus pathogenicity in the inoculated pigs. Animal inoculation studies were conducted to determine the pathogenicity of PRRSV and to identify other possible agents present in the original specimens. Pigs inoculated with PRRSV alone and their contacts showed persistent fever, and two of five pigs developed cough, neurological signs and swollen joints. Necropsy examination showed mild to moderate bronchopneumonia, enlarged lymph nodes, fibrinous pericarditis and polyarthritis. PRRSV was re-isolated from blood and tissues of the inoculated and contact pigs. Pigs inoculated with lung and spleen tissue homogenates from sick pigs from Vietnam developed high fever, septicaemia, and died acutely within 72 h, while their contact pigs showed no clinical signs throughout the experiment. Streptococcus equi subspecies zooepidemicus was cultured, and PRRSV was re-isolated only from the inoculated pigs. Results suggest that the cause of the swine deaths in Vietnam is a multifactorial syndrome with PRRSV as a major factor.

Relationship between serum cytokines profiles and hepatic fibrosis in schistosomiasis mansoni: an experimental study.

Forty of eighty mice (10 each group) were infected with S. mansoni cercariae and sacrificed at 3 weeks (G-A), 6 weeks (G-B), 12 weeks (G-C) and 16 weeks (G-D) post infection (P.I). The other forty mice were used as control groups of ten mice each. There were highly significant difference between egg counts after 12 weeks & 16 weeks of infection compared to 6 weeks P.I. The maximum egg count and mature eggs were in 6th week P.I while dead eggs reached the peak at 16th weeks P.I. Liver egg counts showed maximum followed by intestinal and then, stool egg counts. A highly significant differences in hydroxyproline, TGF-Bland IL-4 of infected than in controls and their peak at 16 weeks P.I. A significant difference in the IFN-gamma in the infected than in controls with peak occurred at 6 weeks P.I. and declined after that reaching a low level at 16 weeks P.I. A highly significant positive correlation was between TGF-Bland IL4 and significant negative correlation between IFN-gamma and both IL4 & TGF-B1. A highly significant and significant negative correlation between TGF-B1 and egg count at 12 & 16 weeks P.I respectively. Negative correlation was between IL-4 and egg count at 16 weeks P.I. But, significant positive correlation was between IFN-gamma with the egg count at 16 weeks P.I. A significant negative correlation was between TGF-B1 and oogram at 6 & 16 weeks P.I, but highly significant positivity was between IFN-gamma and oogram at 16 weeks P.I. A significant negative correlation was between IL-4 and oogram at 16 weeks P.I. A significant positive correlation was between levels of hydroxyproline and TGF-B1 at 12 & 16 weeks P.I. Highly significant negative correlation between hydroxyproline and IFN-gamma was at 12 weeks P.I with significant and highly significant positive correlation between hydroxyproline and IL4 at 12 & 16 weeks P.I.

Evaluation of circulating Fasciola antigens in specific diagnosis of fascioliasis.

Ninety-eight individuals were included in this study, 60 of them were passing Fasciola eggs, 20 were infected with other parasites but not Fasciola (infected control group) and 18 individuals were free from parasite infection (normal control group). Circulating Fasciola antigens (CFAg) and anti-Fasciola IgG were estimated by ELISA technique among all groups. Highly significant increased level of CFAg was observed among Fasciola-infected cases when compared with normal control group. The percentage positivity of CFAg was 95% among Fasciola-infected cases. Solid specificity was observed by the test. Moreover, a highly significant increase in the antigen level was detected among moderately infected patients compared with lightly infected group. The level of CFAg was significantly higher in the hepatomegalic cases than those without organomegaly. Anti-Fasciola IgG antibodies were detected in only 35% of Fasciola infected cases, which indicates much lower sensitivity of the antibody detection than antigens. No correlation between the level of the circulating antibodies and either the intensity of infection or the clinical presentations was observed.