Evaluating two approaches for using positive control in standardizing the avian influenza H5 reverse transcription recombinase polymerase amplification assay

Highly pathogenic avian influenza H5N1 virus causes heavy losses in poultry farms worldwide. Molecular diagnostic techniques like RT-PCR and real-time RT-PCR are considered the gold standard for identification of H5 influenza viruses in clinical samples. These techniques are hampered by the need of well-equipped laboratories, large space requirement, and relatively long time-to-result. Recombinase polymerase amplification (RPA) assay represents an excellent alternative to PCR since it is more simple, rapid, economic, and portable. Reverse transcription RPA (RT-RPA) assay was recently developed for sensitive and specific detection of H5N1 virus in 6-10 min. To ensure the accuracy of the developed assay, two approaches for using a positive control were evaluated in this study. These approaches included: 1) all-in-one (internal positive control; IPC), 2) two-tubes-per-one-sample (external positive control; EPC). Sigma virus (SIGV) RNA and turkey mitochondrial DNA were tested as positive controls in both approaches. For all-in-one approach, both targets (H5 and IPC) were strongly inhibited. In contrast, very good amplification signals were obtained for the two types of EPC with no effect on the analytical sensitivity and specificity of H5 RT-RPA assay in two-tubes-per-one-sample approach. The performance of EPC-based H5 RT-RPA was further validated using 13 tracheal swabs. The results were compared to real-time RT-PCR and proved superior specificity in detecting H5N1 but not H5N8 viruses. Inclusion of EPC did not affect the aptitude of both assays in terms of sensitivity, specificity and reproducibility. In conclusion, the two-tubes-per-one-sample approach was more reliable to control the false negative results in H5 RT-RPA assay.

Oxidative stress during erythropoietin hyporesponsiveness anemia at end stage renal disease: Molecular and biochemical studies

Inflammation and oxidative stress are two faces of one coin in end stage renal disease patients (ESRD) on maintenance hemodialysis. Their interconnection induces anemia complicated with erythropoietin hyporesponsiveness. The biochemical bases behind the resistance to erythropoietin therapy with frequent hemoglobinemia, oxidative stress and iron status have not been fully understood. Here two equal groups (40 patients each) of responders and non-responders to recombinant human erythropoietin therapy (higher than 300 IU/kg/wk of epoetin) were investigated. Hematological and biochemical analyses of collected blood and serum samples were performed along with serum electrophoretic protein footprinting. The leukocytic DNA fragmentation was used to evaluate the degree of oxidative insult. The good responders showed lower erythrocyte malondialdehyde (E-MDA) level and less DNA fragmentation of circulating leukocytes than poor responders with elevated hemoglobin, albumin, A/G ratio, total iron, and ferritin levels. Contrariwise, lower erythrocyte superoxide dismutase (E-SOD) and catalase activities in EPO poor responder group were noticed. Neither other serum constituents nor electrophoretic protein pattern showed any difference between the two groups. There were higher levels of inflammatory markers, interleukin-6 (IL6) and C-reactive protein (CRP) in EPO poor responder than good responder. The negative correlations between Hb and both IL6 and CRP levels in the present data remotely indicate a positive correlation between inflammatory markers and severity of anemia. A direct correlation between Hb and antioxidant enzymes (E-SOD and catalase) was noticed, while inverse correlation with E-MDA was recorded. The study proved that oral supplementation of vitamin C to ESRD patients might mitigate the previously elevated serum MDA level in these patients.

Effect of ginseng extract supplementation on testicular functions in diabetic rats

OBJECTIVE

It was aimed to investigate the effect of standardized ginseng extract on fertility parameters in diabetic rats.

METHODS

Thirty male rats were randomly allocated into three groups of 10 rats each: 1. controls, 2. diabetes (D) and 3. diabetes + ginseng (DG). The latter two groups were rendered diabetic by i.p. injection of streptozotocin (STZ; 50 mg/kg). Standardized ginseng extract (Dansk Droge A/S, Copenhagen, Denmark) was administered per os (100 mg/kg BW) by stomach tube daily for 90 days starting one week after STZ. Ninety days post STZ the rats were sacrificed, and testis, epididymis, prostate, and seminal vesicles were weighed and subjected to histological examination. In addition, spermiogram, testicular enzyme markers, intratesticular steroid hormonal profile and testicular antioxidant status were estimated.

RESULTS

The administration of ginseng extract resulted in a significant improvement of fertility parameters and testicular antioxidants together with a decrease in malondialdehyde and testicular pathological signs including degenerative changes of the seminiferous tubules.

CONCLUSION

Ginseng extract may be a beneficial adjuvant therapy for diabetics suffering from infertility as a complication.

Creatine phosphokinase and aspartate aminotransverase profiles and its relation to the severity of uterine torsion in Egyptian buffalo

Thirty-five female buffalo suffering from uterine torsion were brought to the veterinary clinic and were clinically examined as well as monitored using trans-rectal and trans-abdominal ultrasonography. Three blood samples were taken from each animal (before re-torsion, 1h and 24h after delivery) to investigate the relationship between the serum concentrations of creatine phosphokinase (CPK), aspartate aminotransverase (AST) and the severity of uterine torsion. The incidence of uterine torsion was greater in multiparous than young buffalo. The concentration of CPK and AST showed a significant (P<0.05) increase with increased duration and severity of uterine torsion. However, the concentration of CPK was less in the cases delivering a live foetus than a dead one. Animals with CPK above 450 IU usually had uterine rupture during labour (85.7%) and CPK level above 500 U/l did not respond to treatment. After labour, the AST concentration reached normal in some cases (1-6 and 24-48h). Animals with AST above 100 U/l may be either not respond to the re-torsion procedures or respond but exposed to uterine rupture during vaginal delivery. Occurrence of the uterine torsion is usually accompanied by an elevation (P<0.05) of AST concentration regardless the degree, position and viability of the foetus (76.47-100.25 U/l vs. 59.43 U/l). Animals with severe torsion or carrying a dead foetus had greater (P<0.05) AST compared to those having a mild degree or carrying live foetus. After labour, the concentration of AST decreased (P<0.05) but never reached normal concentrations up to 24h except in animals having a live foetus. In conclusion, concentration of CPK and AST can be used as a prognostic indicator for the occurrence of uterine torsion in Egyptian buffalo.

Quality assurance in measuring the elemental composition of the alga Fucus vesiculosus

Algae are increasingly used for the purpose of environmental biomonitoring, for instance in the long-term program of the Federal Environmental Specimen Bank of Germany. Therefore, for the studies presented here, freeze-dried samples of Fucus vesiculosus collected from the North Sea shores were analyzed for a broad range of elements by instrumental neutron activation analysis (INAA), while inductively coupled plasma atomic emission spectrometry (ICP-AES) and mass spectrometry (ICP-MS) were carried out on digests. The entire analytical procedures, including field sampling, cleaning of material, sample handling, determination of blanks and instrumental parameters, are described. Certified reference materials analyzed in parallel with real samples and intermethod comparisons were used for assuring the accuracy of the analytical data. Reproducibility of INAA measurements was between 4 and 6% depending on the element considered. Possible sources of uncertainty and variation of the contaminant origins are discussed. Boundary conditions for the performance of algae sampling within environmental monitoring programs and the application of this marine bioindicator for the purpose of controlling time-dependent and local differences in element patterns are presented.

Toxicological potential of malathion residues in stored soybean seeds

Succinate-14C-malathion penetrates readily into soybean seeds. The total internal residues inside the seeds amounted to 58-65% of the applied dose after 30 weeks, of which 8-9% were in the form of bound residues. The major part of the internal methanol extractables are chloroform soluble metabolites which include malathion (about 60%), monocarboxylic acid (15%) and its decarboxylation product (8%). The water soluble metabolites contained only one radioactive substance, namely malathion dicarboxylic acid. The toxicological potential of the total internal residues was studied by feeding mice with the washed seeds for about 2.5 months. Treated mice suffered from deterioration of hepatic and renal function as indicated by the observed increased level of blood serum esterases and blood urea nitrogen. The results of blood biochemistry are supported by the histopathological changes observed in the liver, kidney, stomach and intestine. The organs showed degenerative changes including leucocytic aggregation, congestion and dilatation of blood vessels. Other adverse effects caused by malathion residues are indicated from cytogenetic studies on bone marrow of treated mice. Studies showed an initial bone marrow toxicity as indicated by increase in percentage of polychromatic erythrocytes over controls. This effect diminished upon prolongation of feeding period over one month. Feeding with malathion residues affected a gradual increase, with feeding period, in the percentage of polychromatic erythrocytes with micronuclei, a parameter recommended for detecting chemical mutagenes in animal test systems.

Effect of thiamine, magnesium, and sulfate salts on growth, thiamine levels, and serum lipid constituents in rats

Six variable supplementations of thiamine magnesium, and sulfates were given to 30 male adult rats in their diets. After 3 weeks, the concentrations of thiamine in the blood and liver and those of cholesterol, phospholipids, and triglycerides in the serum were determined. Blood thiamine level did not reflect the vitamin content in liver. Sufficient and/or excessive intake of the 3 supplementations caused an increase in liver thiamine content and body weight gain; it also caused a reduction in serum cholesterol level without a change in the levels of serum triglycerides and phospholipids. Deficiency of both magnesium and sulfate salts in thiamine-supplemented groups decreased body weight gain and liver thiamine content with a significant elevation of serum triglycerides.

Effects of steroid anaesthesia on some liver function tests in goats

The effect of Saffan, a steroid anaesthetic, on the liver function of goats has been studied. Forty healthy animals were divided into 4 equal groups. The first 2 groups were given 2 and 4 mg Saffan/kg b. wt respectively. A mixture of Saffan (1 mg) and Xylazine (0.1 mg)/kg b. wt was given to the third group and Xylazine alone to the fourth group (0.1 mg/kg b. wt). Serum samples from all groups were analysed for glucose, total protein, total and direct bilirubin and the level of activity of transaminases. Administration of Saffan evoked more hyperglycemia than a mixture with Xylazine, or Xylazine alone. The hyperglycemic effect of both doses of Saffan (2 and 4 mg) was equivocal beyond 2 h. The effect then differed and glucose was increased 4-fold by 2 mg and 3-fold by 4 mg Saffan. Serum total protein, conjugated and total bilirubin, and GPT and GOT were not changed in the four experimental groups. This was good evidence of a normally functioning liver during the course of steroid anaesthesia administration in goats.

Influence of dietary mineral imbalance on the incidence of urolithiasis in Egyptian calves

The influence of certain dietary elements on the urolithiasis syndrome in cattle calves was elucidated. Calcium, phosphorus, and magnesium measurements were conducted on feed rations as well as on serum and urine samples collected from affected and normal calves. Analysis of the rations given to the animals showed phosphorus at higher levels than calcium, indicating mineral imbalance. Serum and urine of urolithic calves were characterised by high phosphorus, calcium, magnesium, urea, and creatinine levels. Physical examination of urine of affected animals showed a high degree of turbidity, a large amount of calcium carbonate, and triple phosphate as well as abundant amount of pus cells and red blood cells. The characteristic clinical symptoms of urine retention were observed. Moreover, some animals were found to urinate through an opening in front of the scrotal region.

Cardiac abnormalities and exercise tolerance in patients receiving renal replacement therapy

The exercise tolerance of the survivors of a consecutive group of 100 patients in a renal dialysis and transplant programme was compared with the prevalence of cardiac abnormalities detected by exercise testing, echocardiography, and radionuclide angiography. Fifty four patients attended for investigation 27 (SD 7) months after starting renal replacement therapy. Forty three of them (80%) were receiving antihypertensive treatment. Their performance on a bicycle ergometer exercise test was compared with that of 62 normal subjects and the patients divided into five groups of decreasing ability. The exercise tolerance of the patients was very poor, only 17 performing within the normal range. Impairment in exercise capacity was not explained by the type or quality of renal replacement therapy. Fourteen patients developed ischaemic electrocardiographic changes on exercise. Left ventricular ejection fraction was assessed by gated blood pool scanning in 37 patients; all nine of the patients with an abnormally low radionuclide ejection fraction also had abnormal exercise tolerance. Satisfactory M mode echocardiograms were obtained from 45 of the patients, and only two were normal. Left ventricular hypertrophy was detected in 25 (56%) of the echocardiograms, and abnormalities indicating impaired left ventricular function were common and widespread. Grouping all the abnormal cardiac features together for the patients in each exercise group showed a striking linear trend of increasing proportion of cardiac abnormalities with worsening exercise tolerance among the five exercise groups (p less than 0.001). The proportion of patients becoming unemployed within one year of starting renal replacement therapy similarly increased, from nil to 60% from the best exercise group to the most incapacitated. Twenty nine of the original cohort of 100 patients subsequently died, cardiovascular disease accounting for 12 (41%) of these deaths. Diminished exercise tolerance in patients receiving renal replacement therapy is strongly associated with cardiac abnormalities and reduced employment prospects.