Genistein causes germ cell reduction in the genital ridges of Japanese quail Coturnix japonica embryo.

Genistein (GEN), an isoflavonoid phytoestrogen, is one of the potent estrogenic compounds derived from plants that can cause disrupting effects on sex organ development in non-mammalian and mammalian species. The present study revealed effect of genistein on germ cell number in the genital ridges during gonadogenesis. Genistein (16 and 24 µg/g egg) was injected into the egg yolk prior to incubation. Effect of genistein on quail-primordial germ cells (PGCs) number was examined by counting the number of Wisteria floribunda (WFA)-positive cells localized in both left and right genital ridges compared with the control group. Both concentrations of genistein resulted in significant decrease of PGC number compared with the control group. Percentages of the sterility rate of the embryo treated with 16 and 24 µg of genistein/g egg were 19% and 23%, respectively. These results provide evidence that genistein may be a germ cell toxicant causing sterility later in life of adult birds. This is the first report on the effect of genistein on PGC number in the genital ridges of the avian embryo.

Recommended guidelines for submission, trimming, margin evaluation, and reporting of tumor biopsy specimens in veterinary surgical pathology.

Neoplastic diseases are typically diagnosed by biopsy and histopathological evaluation. The pathology report is key in determining prognosis, therapeutic decisions, and overall case management and therefore requires diagnostic accuracy, completeness, and clarity. Successful management relies on collaboration between clinical veterinarians, oncologists, and pathologists. To date there has been no standardized approach or guideline for the submission, trimming, margin evaluation, or reporting of neoplastic biopsy specimens in veterinary medicine. To address this issue, a committee consisting of veterinary pathologists and oncologists was established under the auspices of the American College of Veterinary Pathologists Oncology Committee. These consensus guidelines were subsequently reviewed and endorsed by a large international group of veterinary pathologists. These recommended guidelines are not mandated but rather exist to help clinicians and veterinary pathologists optimally handle neoplastic biopsy samples. Many of these guidelines represent the collective experience of the committee members and consensus group when assessing neoplastic lesions from veterinary patients but have not met the rigors of definitive scientific study and investigation. These questions of technique, analysis, and evaluation should be put through formal scrutiny in rigorous clinical studies in the near future so that more definitive guidelines can be derived.

Diagnosis of Helicobacter spp. infection in canine stomach.

A total of 75 biopsied samples of cardia, fundus, body, and pyloric antrum from necropsied dogs that were submitted to the Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University from April 2003 to June 2004 were investigated. The objectives of this study were to determine the prevalence of Helicobacter spp. in canine stomach by polymerase chain reaction (PCR) in comparison to histochemistry versus immunohistochemistry (IHC), and to correlate these diagnostic methods with the clinical significance in infected dogs. Histopathological results revealed 60.0% (45/75) of samples to be positive, and consisted of mild gastritis in 64.44% (29/45), moderate gastritis in 11.11% (5/45), and severe gastritis in 24.44% (11/45). The proportion showing no histopathological lesions was 40.0% (30/75). Helicobacter spp. were localized to the luminal crypt in 18.67% (14/75), gastric pit in 22.67% (17/75), gastric gland in 21.33% (16/75), and gastric epithelium in 8% (6/75). The percentages of positive samples of Helicobacter spp. diagnosed by hematoxylin and eosin stain (H&E), Warthin Starry stain (WSS), IHC with rabbit polyclonal anti-H. pylori antibody, and PCR were 17.3% (13/75), 46.7% (35/75), 30.7% (23/75), and 10.7% (8/75), respectively. No significant differences were observed in histopathological changes in portions of the stomach (p > 0.05). The diagnosis of Helicobacter spp. by PCR in comparison to that by WSS and IHC was not significantly different (p > 0.05). There were no relationships between pathological studies using H&E, WSS, and IHC, and especially between PCR and clinical signs of Helicobacter spp. infections in canine stomachs (p > 0.05). The present study revealed significantly different levels of correlation for Helicobacter spp. detection between H&E and WSS (p < 0.001). Results indicate that the method of choice for diagnosis of Helicobacter spp. infection in canine stomach is dependent on the purpose of study and appropriate specimen collection.

Chitosans as nasal absorption enhancers of peptides: comparison between free amine chitosans and soluble salts.

A total of three free amine chitosans (CS J, CS L and CS H) and two soluble chitosan salts (CS G and CS HCl) were evaluated for their efficacy and safety as nasal absorption enhancers of peptides based on in situ nasal perfusion and subacute histological evaluation in rat. At 0.5% w/v, all chitosans were effective in enhancing the nasal absorption of [D-Arg(2)]-Kyotorphin, an enzymatically stable opioid dipeptide. The enhancing effect of the free amine chitosans increased as the pH was decreased from 6.0 to 4.0 (P<0.05). However, the pH effect was not significant for the two chitosan salts (P0.05), suggesting that their adjuvant activity may be less pH-dependent than the free amine form. CS J and CS G were subsequently selected for further studies. At only 0.02% w/v, their enhancing effect was already significant and comparable to that of 5% w/v hydroxypropyl-beta-cyclodextrin (HP-beta-CD). Both chitosans at 0.1% caused minimal release of total protein and phosphorus from the rat nasal mucosa, with the values similar to that of 5% HP-beta-CD. At 0. 5% the two chitosans also stimulated smaller release of lactate dehydrogenase, an intracellular enzyme used as marker of nasal membrane damage, than 1.25% dimethyl-beta-cyclodextrin. Morphological evaluation of the rat nasal mucosa following 2-week daily administration indicated that the two chitosans (1.0%) produced only mild to moderate irritation. In conclusion, both the free amine and the acid salt forms of chitosans are effective in enhancing the nasal absorption of [D-Arg(2)]-Kyotorphin and have potential for further studies as a safe and effective nasal absorption enhancer of peptide drugs.

The Relevance of CD117-Immunocytochemistry Staining Patterns to Mutational Exon-11 in c-kit Detected by PCR from Fine-Needle Aspirated Canine Mast Cell Tumor Cells.

Canine cutaneous mast cell tumors (MCT) are the lethal skin tumors. The biological behavior of the MCT cells is quite varied and unpredictable. Almost MCT dogs usually require a rapid diagnosis and therapy. However, MCT diagnosis and prognosis are still dependent on histopathology which is rather inconvenient, time-consuming, painful, and harmful for some cases. Indeed, MCT can be easily accessible using fine-needle aspiration (FNA). In this study, our biopsy specimens were classified as low- and high-grade MCT based on the novel 2-tier histopathologic grading system. We have demonstrated the usage of fine-needle aspirated MCT cells (FNA-MCT cells) from these specimens as a primary cell source to study the distribution of CD117-immunocytochemistry (CD117-ICC) staining patterns and the frequency of internal tandem duplication- (ITD-) mutant exon-11 of c-kit. The result has substantially shown that there were three staining patterns identified in the cells. Only paranuclear pattern was significantly increased in the cells from high-grade MCT. Altogether, the ITD-mutant exon-11 was also detectable only in these cells. Therefore, the result has supported our hypothesis that there was an increased opportunity to observe a higher CD117-ICC staining pattern and exon-11 mutation in high-grade MCT; even these two parameters may not precisely indicate a histopathological grade.