Staining pattern of the brush border and detection of cytoplasmic granules in the uriniferous tubules of female DBA/2Cr mouse kidney: comparison among various fixations and stains.

The proximal straight tubules of the female mouse kidney exhibit heavy periodic acid Schiff (PAS) staining in their brush borders and numerous cytoplasmic granules. In the present study, the female DBA/2Cr mouse kidney was examined, using various fixatives (formalin, PFA, PLP, Zamboni's, Bouin, or Carnoy solution) and various staining methods (HE, PAS, alcian blue, periodic acid methenamine-silver (PAM), toluidine blue, azan, or Congo red). Under azan and PAM, the staining pattern of the brush border was similar to that of PAS, and few effects of the fixative were observed. Cytoplasmic granules were clearly detected with PAM as well as PAS. However, these granules were not detected with Carnoy solution. Furthermore, distribution of granules differed between PAS and PAM.     

Effects of estrous cycle on the mouse kidney morphology

Although mice kidney morphology shows various sexual dimorphisms, the effect of the estrous cycle has not previously been discussed. In this study, we investigated the effects of the estrous cycle on kidney morphology, including renin-positive areas, of female DBA/2 mice. No effects were confirmed in most of the histometrical parameters, however, the percentage of the renal corpuscles in which cuboidal epithelium covered under 50% of the parietal layer was significantly higher during estrus compared to that during anestrus.     

A Practical Technique for Electron Microscopy of Buffy Coats in Dogs and Cats

Plastic hematocrit tubes (PHTs) are convenient tools for electron microscopy (EM) of peripheral blood buffy coats, and the PHT‐EM technique is expected to be a practical method for veterinary clinical medicine. In this study, fixatives composed of various concentrations of sucrose, glutaraldehyde, and phosphate buffer (PB) were tested for preparing canine and feline buffy coats. The highest quality images were obtained using a fixative consisting of 2.5% glutaraldehyde in 0.1 m PB, and it was concluded that this method allows clinicians who are inexperienced in histological techniques can conveniently transport buffy coat samples to diagnostic laboratories for analysis by EM.     

Density effects on length at maturity of walleye pollock <Emphasis Type="Italic">Theragra chalcogramma</Emphasis> off the pacific coast of northern Japan in the 1990s

To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of age-3-5 fish decreased, but the condition factor and the age at 50% maturity showed no clear trend during this period. Male length at 50% maturity decreased, while value for females showed no clear trend. In both sexes, significant negative correlations were found between density index (combined age-3-5) and each body length at age-3-5. Significant positive correlations were seen between each body length at age-3-5 and length at 50% maturity in males. Positive correlation between body length at age-5 and length at 50% maturity was significant in females from 1990 to 1999, except for the samples in 1998. We suggest that the fish density might affect the length at maturity in males and possibly also in females.     

Trapped neutrophil syndrome in a Border Collie dog: clinical, clinico-pathologic, and molecular findings

Trapped neutrophil syndrome (TNS) is an autosomal recessive inherited neutropenia known in Border Collies since the 1990's. Recently, the causative mutation has been identified in the canine VPS13B gene and a DNA-based diagnosis has now become available. The present paper describes clinical and clinico-pathologic findings in a Border Collie with TNS that was molecularly diagnosed for the first time in Japan. In a 10-week-old male Border Collie with microgenesis and symptoms related to recurrent infections, a hematological examination revealed severe leukopenia due to neutropenia, suggesting the dog to be affected by inherited neutropenic immunodeficiency. Direct DNA sequencing demonstrated that the dog was homozygous for the causative mutation of TNS and both its parents were heterozygous carriers. In addition, a simple and rapid polymerase chain reaction-based length polymorphism analysis coupled with microchip electrophoresis was developed for the genotyping of TNS. This assay could discriminate clearly all genotypes, suggesting that it was suitable for both individual diagnosis and large-scale surveys for prevention.     

Immunohistochemical analysis of cyclooxygenase-2 induction during wound healing in dog skin

Cyclooxygenase (COX)-2 is an inducible isoform of COX and is expressed under abnormal health conditions. This study elucidated the cutaneous induction of COX-2 during the wound healing processes in dog skin. Dog skin was sutured after punch biopsy and investigated histologically and immunohistochemically on days 0 (normal), 1, 3, 5, 7, 10, and 14 after injury. Histological changes, including infiltration of inflammatory cells and proliferation of fibroblast-like cells, were observed as predicted, and there was a close and significant correlation between these 2 events. COX-2-positive cells were detected in the epidermis between days 1 and 7, and bimodal peaks were observed in the case of the percentage of COX-2-positive cells. In inflammatory cells, COX-positive signals were detected on day 3 only. Here, we clarified the localization and pattern of the induced COX-2 expression during wound healing in dog skin.     

Strain differences in morphometrical characteristics of rat kidneys

To clarify the strain differences in the morphology of the rat kidneys, we investigated the morphometrical characteristics of the kidneys of Slc:Wistar, Slc:SD, and F344/NSlc rats. The diameter of the renal corpuscles in female F344/N rats is smaller than that in female Wistar rats. Although sex differences (males>females) were shown in SD and F344/N rats, no effects of castration were detected in any of the groups. Strain-dependent differences in the percentage of renal corpuscles with a cuboidal parietal layer were found in both male and female groups. The highest percentage of them was noted in male Wistar rats. Effects of castration were observed in female Wistar and male F344/N rats, and the values after castration were significantly higher than those in the intact animals. As for the number of proximal convoluted tubular nuclei, no strain differences were detected in either the male or female groups. Although a sex difference was found in SD rats (female>male), no effects of castration were detected in any of the groups. In female F344/N rats, numerous numbers of PAS-positive granules, which were observed in the proximal convoluted and straight tubular epithelia, were noted. Orchiectomy induced an increase of these granules in male SD and F344/N rats, but ovariectomy showed no effects on them in any strains. This is the first study to clarify the strain differences in the morphological characteristics of the kidneys in ordinary rat strains.     

Mass-processing method for aging otoliths of walleye pollock <Emphasis Type="Italic">Theragra chalcogramma</Emphasis> using black resin

ABSTRACT:   The reliability of a mass-processing aging method for walleye pollock Theragra chalcogramma was examined. The method is a half-otolith method, in which 10–20 otoliths are embedded simultaneously in black resin and the mass-processed half plane section is viewed under reflected light (black-resin method). Seasonal periodicity of otolith growth was confirmed by the monthly observations of the percent of translucent zone at the otolith edge, and interannual variation in age distribution detected the progression of dominant year-classes. These results support the assumption that the translucent zone is formed once a year. The black-resin method was compared to the break–burn method, which is the standard technique for this species. The estimated ages of these methods were not biased throughout the age range examined. The coefficient of variation in the black-resin method (4.9–5.7%) was similar to those of the break–burn method (3.5–5.5%). These results suggest that the black-resin method is reliable as an aging method for walleye pollock.     

Morphometrical analysis of the kidney from nonobese diabetic (NOD) mice in the non-diabetic stage

The kidneys of non-diabetic NOD and wild type ICR mice were examined morphometrically at 3 and 6 months of age. Kidney weights and diameter of renal corpuscles of non-diabetic NOD mice were less than those of ICR mice. No lesions were observed in glomeruli or uriniferous tubules. Renin-positive areas were more common in NOD mice than in ICR mice, but no differences were detected in the Western blot analyses.