Cytometric and cytochemical study of peritoneal and alveolar macrophages from Yersinia pseudotuberculosis infected ground squirrels (Citellus citellus).

The enzymic activity (succinate dehydrogenase, acid and alkaline phosphatase) of alveolar and peritoneal macrophages as well as leucocytic reaction of ground squirrels infected with Yersinia pseudotuberculosis (I and III serovar) have been investigated in dynamics from the 1st up to the 30th day. The animals infected with III serovar survived only to the 7th day, while those infected with I serovar survived up to the 30th day after inoculation. A massive influx of leucocytes having peak values (100-fold increase) on the 3rd day after infection has been found in the peritoneal cavity of the animals infected with I serovar. Moderate leucocytosis in the blood, and insignificant fluctuations in alveolar macrophage number have been established too. An earlier and higher activation of succinate dehydrogenase in alveolar and peritoneal macrophages from animals infected with III serovar in comparison with those infected with I serovar was observed. No differences in alkaline phosphatase activity of alveolar and peritoneal macrophages have been found between the animals infected with I and III serovar. A correlation has been found between the number of leucocytes and changes in the enzymatic activity of the macrophages. A metabolic transformation was demonstrated typical for different macrophages (peritoneal and alveolar), in the course of this experimental intraperitoneal infection. Obviously, more virulent serovar III of Y. pseudotuberculosis fails to attract leucocytes to the peritoneal cavity sufficiently quickly, so it overcome the local protective mechanisms with consequent systemic cytochemical changes. On the other hand the virulent serovar I attracts leucocytes to the peritoneum and is presumably destroyed by them.     

Seasonal change of circulating leptin associated with testicular activities of the wild ground squirrels (Citellus dauricus)

The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities. Hematoxylin-eosin staining showed all types of elongated spermatids and spermatogenic cells existed in the testis in April, while the primary spermatocytes and spermatogonia were most advanced stages of germ cells in June. In addition, the primary spermatocytes, secondary spermatocytes, and spermatogonia were most advanced stages of germ cells in September. The highest circulating leptin concentration was consistent with the maximum body weight results from accumulation of adipose tissue in September. The mRNA expression level of leptin receptor (Ob-R) and STAT3 was lowest in June, raised in September, and remained increased in April. Ob-R and STAT3 were stronger staining in the Leydig cells in July. Moreover, the concentrations of testosterone (T) showed the maximum values in April, the minimum values in June, and significant increases in September. Furthermore, it is worth noting that the levels of T increased with the mRNA levels of Ob-R, STAT3, StAR, and testicular steroidogenic enzymes (3β-HSD, P450c17, and P450scc). Moreover, RNA-seq analyses of testis during the different periods showed that a total of 4209 genes were differentially expressed genes (DEGs); further analysis revealed that DEGs related with the Jak/STAT pathways and reproduction were altered. Taken together, the results suggested that the leptin regulated testicular function through the Jak/STAT pathways and testicular steroidogenic factor expressions.     

Harderian gland neoplasms in captive, wild-caught Beechey ground squirrels (Spermophilus beecheyi)

Harderian gland neoplasms were identified in 18 aged, adult Beechey ground squirrels (Spermophilus beecheyi) from the records of 167 wild-caught captive animals that were necropsied. All but one animal had tumors that were classified as carcinomas, with infiltrative growth and frequent metastases. This is the first detailed report of Harderian gland neoplasia in wild Sciuridae, although this neoplasm has been described in other rodent species. Clinically, affected ground squirrels typically were inappetent and presented with weight loss and exophthalmos. The biologic behavior of Harderian gland neoplasia is variable among rodent species; in Beechey ground squirrels there was a high incidence of malignant behavior. Eleven of 17 tumor-bearing animals for which the gender was known were male, and 6 were female. Nine of 16 for which data were available were uninfected, and 7 had evidence of current or prior infection with ground squirrel hepatitis virus. Tumor development occurred in older animals; all but 2 were 5.5 years of age or older. The presence of metastasis was not related to gender or chronic ground squirrel hepatitis virus infection.     

The recovery of a Mycoplasma from Citellus richardsonii richardsonii (ground squirrel).

Swabs from the upper respiratory tract, external genitalia and the eyes and portions of the lungs, spleen, kidney, liver and uteri of two ground squirrels were cultured for mycoplasma. The upper respiratory tracts of both animals were positive for mycoplasma as were the lungs, liver and spleen of one of the animals. Preliminary serological studies, growth inhibition test against 38 known antisera, growth precipitation against 15 antisera and fluorescent antibody technique with eight conjugates have, with the exception of a minor precipitin reaction against Mycoplasma bovirhinis, all been negative. The isolates are believed to be representative of either one or more new mycoplasma species.     

Pathology of Sarcocystis campestris infection in Richardson''s ground squirrels (Spermophilus richardsoni).

Richardson's ground squirrels were infected with 1500 or 9000 sporocysts of Sarcocystis campestris from badgers. No lesions were found in animals killed one to three days postinfection (pi). Hepatitis and phlebitis of hepatic veins were present in animals killed between four and eight days pi. No meronts were detected in these animals, but the lesions suggested that a generation of merogony occurred in the hepatic veins. Meronts were found in endothelial cells in many tissues beginning on day 9 pi. They were most numerous on day 10 pi, and less so on day 11, and subsequently. Meronts were most numerous in the lung; none was found in liver or spleen. Four of ten squirrels infected with 1500 sporocysts in one trial died between days 11 and 13 pi. There were petechial hemorrhages in skeletal muscle, lung, serosal membranes, and brain in these animals, with microscopic evidence of pulmonary, myocardial, and brain injury. One animal infected with 9000 sporocysts had petechiae in the liver at six days pi. Foci of inflammation were visible in the myocardium and brain of animals killed to 64 days pi. This species may serve as an experimental model for sarcocystosis in domestic animals.     

达乌尔黄鼠精子形成和细胞色素芳香化酶免疫位置的季节变化

用组织学和免疫组织化学方法调查达乌尔黄鼠精子形成季节性变化和细胞色素芳香化酶(P450 arom)在精巢和附睾中的免疫位置。黄鼠繁殖期与非繁殖期精巢大小、重量、生精小管直径存在显著差异;黄鼠繁殖期精巢中存在从精原细胞到有尾精子各期生殖细胞,非繁殖期精巢中只存在精原细胞和初级精母细胞。另外,繁殖期黄鼠附睾管中存在大量有尾精子,而非繁殖期附睾中未见精子存在。繁殖期P450 arom在黄鼠精巢的间质细胞、支持细胞、精子细胞和附睾头部输出小管上皮细胞都有发现,而在非繁殖期没有发现它的活力。这些结果表明达乌尔黄鼠精子形成、成熟是伴随着精巢复发和退行呈现显著季节性变化,雌激素在精子形成和成熟过程中起着重要的生理性作用。     

Localization profiles of natriuretic peptides in hearts of pre-hibernating and hibernating Anatolian ground squirrels (Spermophilus xanthoprymnus)

The Anatolian ground squirrel (Spermophilus xanthoprymnus) is a typical example of true mammalian hibernators. In order to adapt to extreme external and internal environments during hibernation, they lower their body temperatures, heart rates and oxygen consumption; however, pathological events such as ischemia and ventricular fibrillation do not occur in their cardiovascular systems. During the hibernation, maintenance of cardiac function is very important for survival of ground squirrels. Natriuretic peptides (NPs) are key factors in the regulation of cardiovascular hemostasis. Since NPs’ role on the protection of heart during hibernation are less clear, the aim of this study was to investigate dynamic changes in NPs content in the cardiac chambers and to reveal the possible role of NPs on establishing cardiac function in ground squirrel during hibernation using immunohistochemistry. The immunohistochemical results indicate that cardiac NP expressions in atrial and ventricular cardiomyocytes were different from each other and were sex-independent. ANP and BNP were expressed in a chamber-dependent manner in female and male squirrel hearts. Furthermore, cardiac NPs expression levels in hibernation period were lower than those at the pre-hibernation period. During prehibernation period, ANP, BNP and CNP were expressed in the white and beige adipocytes of epicardial adipose tissue (EAT); while during hibernation period, the brown adipocytes of EAT were positive for BNP and CNP. These data suggest that the hibernation-dependent reduction in levels of NPs, particularly ANP, in cardiac chambers and EAT may be associated with low heart rate and oxygen consumption during hibernation. However, further studies are needed to better delineate the roles of NPs during the hibernation.

     

Seasonal changes in spermatogenesis and immunolocalization of inhibin/activin subunits in the wild male ground squirrel (Citellus dauricus Brandt)

The objective of this study was to investigate the seasonal changes in spermatogenesis and the immunolocalization of the inhibin alpha and inhibin/activin (betaA and betaB) subunits during the breeding and non-breeding seasons in the wild male ground squirrel. The testicular weight and size and seminiferous tubule diameter were measured, and histological observations of testes were performed. The sections of the testes were immunostained by the avidin-biotin-peroxidase complex method (ABC) using polyclonal antisera raised against porcine inhibin alpha, inhibin/activin betaA and inhibin/activin betaB during the breeding and non-breeding seasons. There were marked variations in testicular weight and size and seminiferous tubule diameter between the breeding and non-breeding seasons, and all types of spermatogenic cells, including spermatozoa, were found in the breeding season. In addition, immunoreactivity was also detected for the inhibin alpha, betaA and betaB subunits in Sertoli and Leydig cells during the breeding season, but immunostaining was only present for the inhibin alpha and inhibin/activin betaB subunits in Sertoli cells during the non-breeding season. These results suggest that seasonal changes in testicular weight and size and seminiferous tubule diameter of wild ground squirrels are correlated with changes in spermatogenesis, and the cellular localization of the inhibin/activin subunits showed season related changes in the breeding and non-breeding seasons.     

达乌尔黄鼠染色体组型和G带分析

本文研究了达乌尔黄鼠东北亚种的骨髓细胞染色体组型和Ｇ－带带型。确定其染色体数为２ｎ＝３６，各染色体有其特有Ｇ－带带型。     

Leptospirosis in Wied's marmosets (Callithrix kuhlii).

Two adult Wied's marmosets (Callithrix kuhlii) presented with jaundice, anemia, and weight loss. Death of one individual was attributed to renal tubular necrosis; liver and kidney were positive for Leptospira antigen by immunohistochemical (IHC) staining. The second animal was negative for antigen by IHC staining, but serologically positive for Leptospira borgpetersenii serovar ballum with an eightfold titer increase in paired samples, and was euthanized because of unresponsiveness to treatment. Environmental contamination by mice was suspected as the Leptospira source.