Nephron segment identification in the normal canine kidney by using lectin histochemistry

Lectin-binding patterns in normal canine kidneys were histochemically investigated using eight lectins. WGA, ConA, and RCA-I showed positive signals in glomerular capillary walls, with signals for RCA-I being detected heterogeneously. In tubular segments, signals for WGA, s-WGA, ConA, and RCA-I were distributed widely from proximal tubules to collecting ducts, whereas those for SBA, PNA, DBA, and UEA-I were localized in thin limbs of the loop of Henle, thick ascending limbs, distal tubules, or collecting ducts. Apart from PNA and UEA-I, lectins showed heterogeneous bindings in collecting ducts with the heterogeneity. UEA-I-positive reactions were restricted to those parts of the distal tubules in close proximity to the glomeruli, and in these parts, signals in the macula densa were markedly stronger than in other regions. Based on the present findings, lectin probes, singly or in combination, could be utilized to identify the affected nephron segment in canine renal pathology.     

Gross nitrification rates in four Japanese forest soils: heterotrophic versus autotrophic and the regulation factors for the nitrification

Measurements of gross NH ₄ ⁺ and NO ₃ ^? production in forest soils were conducted using the ¹⁵N pool dilution method. Mineral topsoils (0?C10?cm depth) were collected from four forests from northern to southern Japan with a natural climate gradient to elucidate the mechanisms regulating gross nitrification rates in forest soils. Additionally, we attempted to evaluate the relative importance of heterotrophic nitrification in gross total nitrification using acetylene as a specific inhibitor of autotrophic nitrification. Distinct differences were found among sites in the gross rates of NH ₄ ⁺ production (3.1?C11.4?mg?N?kg^?1?day^?1) and gross total nitrification (0.0?C6.1?mg?N?kg^?1?day^?1). The rates of gross heterotrophic nitrification were low in this study, indicating that heterotrophic nitrification is of minor importance in most forest mineral topsoils in Japan. Significant relations were found between gross autotrophic nitrification and gross NH ₄ ⁺ production, soil N, and soil C concentrations, but none was found between gross autotrophic nitrification and soil pH. We determined the critical value of the gross NH ₄ ⁺ production rates for gross autotrophic nitrification under which no gross autotrophic nitrification occurred, as well as the critical soil C/N ratio above which gross autotrophic nitrification ceased. Results show that tight coupling of production and consumption of NH ₄ ⁺ prevents autotrophic nitrifiers from utilizing NH ₄ ⁺ as long as NH ₄ ⁺ availability is low.     

P-12 Comparative study of griseofulvin and terbinafine therapy in the treatment of canine and feline dermatophytosis

Diagnosis of Microsporum canis infection is a challenge in cats with suspected asymptomatic carriage. The aim of this study was to compare the carpet method and the toothbrush method of sample collection for dermatophyte culture. The study was conducted on apparently healthy cats in a chronically infected cattery. Sampling was performed with both a sterilized piece of carpet and a toothbrush applied to the entire body surface. Samples were inoculated on Sabouraud's media (with chloramphenicol and cycloheximide). Multiple (6) applications with the toothbrush were necessary to obtain a similar surface area of inoculation. Cultures were incubated at 27°C, then examined from day 5 to 21 for the presence and number of colonies of M. canis and other fungi. Some samples were inoculated twice (initially negative or with a low number of M.canis ). A total of 112 cultures were performed (14 duplicates) from 44 cats. On day 21, infection was detected in 23 cats (54.7%): 20 (87%) with the carpet method and 21 (91%) with the toothbrush method. None of the replicated cultures allowed the detection of new cases but three were subsequently negative. In eight cases, only one to six colonies of M. canis were obtained. Both methods used are easy to perform on cats and have a similar sensitivity of approximately 90%. The carpet method is, however, much less expensive, easier to prepare, mail, store and inoculate. The lack of growth in some duplicate cultures (initial development of one or two colonies) may explain the limits of diagnosis of infection and justify the need for multiple inoculations of agar with the toothbrush method.
Funding: Self-funded.     

Suppression of the proliferation of mouse splenocytes by pseudorabies virus

Pseudorabies virus (PRV) infection in resistant swine caused immunosuppression which sometimes resulted in secondary infection by other viruses or bacteria. However the mechanism of the immunosuppression is not well understood. In this study, the effect of PRV on the immune system was examined in the mouse model. Splenocytes or lymphocytes prepared from the spleen of BALB/c mice were incubated in vitro with mitogen, and the ability of cells to proliferation was measured. When the cells were incubated with PRV, the ability of cells to proliferate was inhibited, although PRV did not multiply in the lymphocytes. UV-inactivated PRV also suppressed the proliferation of mice splenocyte. This result suggests that the structural component of PRV virion might cause the immunosuppression.     

In vivo osteoinductivity of gelatin β-tri-calcium phosphate sponge and bone morphogenetic protein-2 on an equine third metacarpal bone defect

This study evaluated the therapeutic effects of a gelatin-β-TCP sponge (sponge) incorporating BMP-2 (BMP-2/sponge) on bone regeneration in equines. Six bone defects were created in third metacarpals of five thoroughbred horses, and a total of six treatments were applied in a randomized manner. The treatments were BMP-2/sponge, BMP-2/gelatin hydrogel sheet (sheet), free BMP-2, bFGF/sheet, plain sponge, and plain sheet. The defects were monitored for 16 weeks by radiography and then examined by histological analysis. Radiographic evaluation scores of bone regeneration revealed significantly greater bone regeneration of defects treated with BMP-2/sponge than defects treated with plain sponge or BMP-2 sheet (P<0.05). In histological analysis, compact bone was observed over a wide area in the BMP-2/sponge treatment. We concluded that the treatment with BMP-2/sponge accelerated bone regeneration in the equines of this study.     

Differential roles of breakfast only (one meal per day) and a bigger breakfast with a small dinner (two meals per day) in mice fed a high-fat diet with regard to induced obesity and lipid metabolism

Background

Recent studies on humans and rodents have suggested that the timing of food intake plays an important role in circadian regulation and metabolic health. Consumption of high-fat foods during the inactive period or at the end of the awake period results in weight gain and metabolic syndrome in rodents. However, the distinct effects of breakfast size and the breakfast/dinner size ratio on metabolic health have not yet been fully examined in mice.

Methods

We examined whether the parameters of metabolic syndrome were differentially affected in mice that consumed a large meal at the beginning of the awake period (breakfast; one meal group) and a relatively smaller meal at end of the awake period (dinner; two meals group). The mice of each group were provided equal food volume per day.

Results

Mice on one meal exhibited an increase in body weight gain, hyperinsulinemia, hyperleptinemia, and a decrease of gene expression associated with ??-oxidation in adipose tissue and liver compared with those on two meals. The circadian expression pattern of the Clock gene in mice on one meal was disturbed compared with those on two meals.

Conclusions

In conclusion, a bigger breakfast with a smaller dinner (two meals per day) but not breakfast only (one meal per day) helps control body weight and fat accumulation in mice on a high-fat meals schedule. The findings of this study suggest that dietary recommendations for weight reduction and/or maintenance should include information on the timing and quantity of dietary intake.     

X-irradiation Removes Endogenous Primordial Germ Cells (PGCs) and Increases Germline Transmission of Donor PGCs in Chimeric Chickens

Primordial germ cells (PGCs) are embryonic precursors of germline cells with potential applications in genetic conservation, transgenic animal production and germline stem cell research. These lines of research would benefit from improved germline transmission of transplanted PGCs in chimeric chickens. We therefore evaluated the effects of pretransplant X-irradiation of recipient embryos on the efficacy of germline transmission of donor PGCs in chimeric chickens. Intact chicken eggs were exposed to X-ray doses of 3, 6 and 9 Gy (dose rate = 0.12 Gy/min) after 52 h of incubation. There was no significant difference in hatching rate between the 3-Gy-irradiated group and the nonirradiated control group (40.0 vs. 69.6%), but the hatching rate in the 6-Gy-irradiated group (28.6%) was significantly lower than in the control group (P<0.05). No embryos irradiated with 9 Gy of X-rays survived to hatching. X-irradiation significantly reduced the number of endogenous PGCs in the embryonic gonads at stage 27 in a dose-dependent manner compared with nonirradiated controls. The numbers of endogenous PGCs in the 3-, 6- and 9-Gy-irradiated groups were 21.0, 9.6 and 4.6% of the nonirradiated control numbers, respectively. Sets of 100 donor PGCs were subsequently transferred intravascularly into embryos irradiated with 3 Gy X-rays and nonirradiated control embryos. Genetic cross-test analysis revealed that the germline transmission rate in the 3-Gy-irradiated group was significantly higher than in the control group (27.5 vs. 5.6%; P<0.05). In conclusion, X-irradiation reduced the number of endogenous PGCs and increased the germline transmission of transferred PGCs in chimeric chickens.     

Cutaneous epitheliotropic lymphoma with dual CD3 and c‐kit expression in a dog

An 11‐year‐old 8.9‐kg spayed female Boston Terrier was presented for evaluation of a mucocutaneous tumor on the right side of the upper lip that had been biopsied (punch biopsy) by the referring veterinarian. The histologic diagnosis was poorly differentiated round cell tumor involving the submucosa with patchy involvement of the mucosa. On presentation of the dog to Louisiana State University, the tumor was found to involve the mucosa and haired skin surface of the right upper lip. A fine‐needle aspirate of the right mandibular lymph node contained atypical poorly differentiated round cells similar to those in the histologic sections. To further characterize the tumor, immunohistochemical analysis of the tumor on the lip was performed; tumor cells were strongly immunoreactive for both CD3 and c‐kit in a cytoplasmic to membranous pattern, with CD3 expression having a more intense membranous component. The diagnosis was cutaneous epitheliotropic T‐cell lymphoma with co‐expression of CD3 and c‐kit by neoplastic lymphocytes, an unusual finding. As receptor tyrosine kinases can be attractive targets for cancer treatment, expression of these molecular targets in tumors is a promising subject of future research.