Evaluation of antibodies against feline coronavirus 7b protein for diagnosis of feline infectious peritonitis in cats

OBJECTIVE: To determine whether expression of feline coronavirus (FCoV) 7b protein, as indicated by the presence of specific serum antibodies, consistently correlated with occurrence of feline infectious peritonitis (FIP) in cats. SAMPLE POPULATION: 95 serum samples submitted for various diagnostic assays and 20 samples from specific-pathogen-free cats tested as negative control samples. PROCEDURES: The 7b gene from a virulent strain of FCoV was cloned into a protein expression vector. The resultant recombinant protein was produced and used in antibody detection assays via western blot analysis of serum samples. Results were compared with those of an immunofluorescence assay (IFA) for FCoV-specific antibody and correlated with health status. RESULTS: Healthy IFA-seronegative cats were seronegative for antibodies against the 7b protein. Some healthy cats with detectable FCoV-specific antibodies as determined via IFA were seronegative for antibodies against the 7b protein. Serum from cats with FIP had antibodies against the 7b protein, including cats with negative results via conventional IFA. However, some healthy cats, as well as cats with conditions other than FIP that were seropositive to FCoV via IFA, were also seropositive for the 7b protein. CONCLUSIONS AND CLINICAL RELEVANCE: Expression of the 7b protein, as indicated by detection of antibodies against the protein, was found in most FCoV-infected cats. Seropositivity for this protein was not specific for the FCoV virulent biotype or a diagnosis of FIP.     

Leptin inhibits mitogen-induced proliferation of peripheral T lymphocytes from Holstein cows

This study examined the mitogenic response of bovine peripheral T lymphocytes to leptin, a pleiotropic hormone regulating food intake and energy expenditure. Leptin alone slightly suppressed proliferation of T lymphocytes in the presence of concanavalin A (ConA). Leptin also inhibited proliferation of T lymphocytes induced by anti-CD3 antibody. ConA treatment activated some protein kinases, including p44/p42(MAPK) and Akt/PKB, while anti-CD3 antibody treatment increased mRNA expression of suppressor of cytokine signalling (SOCS) 3, interferon (IFN)gamma, interleukin (IL) 2 and IL4 in T lymphocytes. Leptin alone increased only SOCS3 mRNA expression. Simultaneous treatment with mitogens and leptin enhanced IFNgamma mRNA expression but decreased IL2 mRNA expression, without any synergistic effect on phosphorylation of protein kinases or mRNA expression of SOCS3 and IL4. These results suggest that leptin modulates bovine T lymphocyte functions.     

Promotive effects of a 5-aminolevulinic acid-based fertilizer on growth of tissue culture-derived date palm plants (Phoenix dactylifera L.) during acclimatization

The low survival rate together with the slow growth rate of the survived tissue culture-derived date palm plants during acclimatization are critical problems facing the tissue culture as a commercial technique of date palm propagation. Growth parameters, pigment contents and nutrient uptake were examined in tissue culture-derived date palm plants (Phoenix dactylifera L.) c.v. ‘Khalas’ subject to different concentration of a 5-aminolevulinic acid-based fertilizer, commercially known as Pentakeep-v, during acclimatization. Pentakeep application at 0.02, 0.04 or 0.08% at 10 days interval significantly enhanced growth at both VP2- and VP3-stage of acclimatization. However, such effects were not detectable at the VP1-stage. At the end of this stage, the successful plants ranged from 66.6 to 78.3% with no significant differences between the Pentakeep treatments and the control. All successful plants at this stage survived both the VP2 and the VP3 stages of acclimatization. Plants treated with Pentakeep, especially at 0.04 and 0.08%, developed faster and were ready for transplanting to the nursery or to the open field conditions about 4–5 months earlier than the control or those treated with 0.02% Pentakeep. Pentakeep significantly increased chlorophyll a contents in all treatments which was subsequently reflected on total chlorophyll and chlorophyll a/chlorophyll b ratio. Pentakeep application, especially at the 0.08%, significantly increased the concentration of N, Cu and Zn in the leaves of treated plants. The concentration of available P and Zn in the soil was significantly higher in the Pentakeep treatments than the control.     

Brucella: a pathogen without classic virulence genes

The first species of Brucella was isolated and characterized almost 120 years ago and recently the complete nucleotide sequences of the genomes of a number of well-characterized Brucella strains have been determined. However, compared to other bacterial pathogens relatively little is known about the factors contributing to its persistence in the host and multiplication within phagocytic cells. Also, many aspects of interaction between Brucella and their host remain unclear. Molecular characterization of intracellular survival process of Brucella is important as it will provide guidance for prevention and control. One of the features that distinguish Brucella is that they do not express classical virulence factors. Thus identification of virulence factors has been elusive and some of the identifications are putative. Disruption of putative virulence genes and studying their effect on attenuation in cell lines or mouse models is a widely used method. However, in most cases it is not apparent whether the mutated genes encode virulence factors or merely affect metabolic pathways of the pathogen. In addition, some mutations in Brucella can be compensated by redundancy or backup mechanisms. This review will examine known virulence genes (real and putative) identified to date and the mechanisms that contribute to the intracellular survival of Brucella and its ability to establish chronic infection.     

Efficacy and safety of ultrasound-guided percutaneous biopsy of the right kidney in cattle

The purpose of the present study was to develop a technique for biopsy of the kidneys of cattle and to evaluate its usefulness and safety based on 25 consecutive biopsies. Using a handheld 14G spinal biopsy needle, the right kidney was biopsied under ultrasound control by one operator. To assess the immediate effects of renal biopsy, twenty cattle were necropsied shortly after the procedure and examined. The remaining five animals were biopsied and examined daily for nine days and then necropsied. One pass was made for biopsy of the right kidney. No immediate or delayed macroscopic hematuria was observed post-biopsy. Six animals had a thin subcapsular hematoma (less than 2 cm in diameter). We conclude that percutaneous ultrasound-guided biopsy of the right kidney is safe, fast, cost-effective and practical as long as it is performed properly.     

Survival and fertility rate of cooled dromedary camel spermatozoa supplemented with catalase enzyme

The present study was planned to study the effects of addition of different concentrations of catalase enzyme (0, 250, 500 and 1,000 IU/ml) to cooled dromedary camel semen extended with tris-yolk-fructose extender on semen quality during storage at 5 C for up to 5 days. Conception rates of she-camels artificially inseminated with whole fresh or extended cooled dromedary camel semen with or without 500 IU/ml catalase enzyme were also estimated. The results showed that addition of catalase enzyme at concentrations of 250 or 500 IU/ml to extended cooled dromedary camel semen significantly increased (P<0.01) the percentage of sperm motility and significantly decreased (P<0.01) the percentages of dead spermatozoa, sperm abnormalities and acrosomal damage. The highest (P<0.01) percentage of sperm motility was recorded with extended cooled dromedary camel semen supplemented with catalase enzyme at a concentration of 500 IU/ml, and the lowest (P<0.01) value was recorded with catalase enzyme at a concentration of 1000 IU/ml. On the other hand, the lowest (P<0.01) percentages of dead spermatozoa, sperm abnormalities and acrosomal damage of spermatozoa were recorded with extended cooled dromedary camel semen supplemented with 500 IU/ml, and the highest (P<0.01) values were recorded with catalase enzyme at a concentration of 1,000 IU/ml. Advancement of the storage time at 5 C significantly decreased (P<0.01) the percentage of sperm motility and significantly increased (P<0.01) the percentages of dead spermatozoa, sperm abnormalities and acrosomal damage of spermatozoa. Moreover, the conception rates of she-camels artificially inseminated with whole fresh, extended cooled dromedary camel semen free-catalase enzyme and extended cooled dromedary camel semen supplemented with catalase enzyme at a concentration of 500 IU/ml were 46.15, 22.22 and 37.50%, respectively. In conclusion, the results show that addition of catalase enzyme at a concentration of 500 IU/ml to semen extender can be used as an agent for prolongation of dromedary camel sperm cell survival during storage at 5 C.     

Microscopic anatomy of the oesophagus in the southern white-breasted hedgehog (Erinaceus concolor) a histochemical,stereological, and scanning electron microscope study

The present work was designed to investigate the microscopic structure of the oesophagus in the southern white-breasted hedgehog (Erinaceus concolor) using histochemical staining, Scanning electron microscope (SEM), and stereological procedures. Four adult males were included in our study. Serial sections of the entire length of the oesophagus were stained with aldehyde fuchsin, alcian blue (pH 2.5), Periodic acid Schiff (PAS), and Masson's trichrome. Then, the total volume of the oesophagus, and the total volume of its different layers, were estimated using Cavalieri's principle. The oesophageal epithelium was a non-keratinized stratified squamous type. Muscularis mucosa was present as a thick layer between lamina propria and submucosa and its thickness was increased toward the stomach. Tunica submucosa was a loose connective tissue containing an oesophageal gland with PAS-positive and AB-positive reactions throughout the submucosa and become denser toward the stomach. The tunica muscularis consisted of two distinct striated muscle layers, and its thickness was decreased toward the stomach. On SEM images, the cervical and thoracic oesophagus showed shallow folding, while the abdominal part had deeper folds. The present findings indicate that the histological properties of the oesophagus in southern white-breasted hedgehogs have slight similarities with rodents and considering its epithelium, submucosal glands and tunica muscularis more resemble with dog oesophagus. The obtained results may be quite helpful to improve the current knowledge of the histophysiology of the hedgehog gastrointestinal tract as a member of eulipotyplan mammals and as a pet for biologists and veterinarians.     

Applications of various stereological tools for estimation of biological tissues

To provide concise and brief important stereological application methods and techniques for estimating biological tissues. Stereology studies the quantity of biological tissue using little practice and the low price of counting and preparing tissue slices to obtain direct and accurate results. Since their establishment, the stereological techniques underwent much improvement, thus allowing more precise analysis of target structures using various approaches. Using stereological tools, advances in stereological techniques made the target tissues or organs represented by 2D instead of 3D dimensions. Process tools estimate volume, area and length. According to the exciting tissue and aims, the stereological tools perform differently. This review summarizes various stereological tools and techniques, providing brief information about the orientation method, slicer probe method, Delesse's principle, Cavalieri principle, disector, fractionator, nucleator, virtual cycloids and saucer, which are described in detail.