Demonstration of substances of innate immunity in the esophageal epithelium of domesticated mammals: Part II - Defence mechanisms, including species comparison

The second part of our study deals with a comparative evaluation and discussion of the immunohistochemical results that were obtained. The cryoscanning electron microscopy (cryoSEM) observations confirmed a monolayer colonization of the esophageal surface with bacteria and fungi (yeasts); the latter in particular was prominent in the ruminant species studied. We demonstrated the existence of several innate immune parameters, including pathogen recognition receptors (PRRs), such as Toll-like receptor 2, which was primarily expressed in the stratum basale; however, the presence β-glucan receptors remained inconclusive. Furthermore, the group of cationic antimicrobial peptides (CAPs) was shown, comprising β-defensins 2 and 3 and cathelicidin. The less keratinized esophageal epithelium of the carnivorous cat was protected by high amounts of CAPs; whereas the more strongly keratinized epithelium of the herbivorous and omnivorous species with its characteristic layer structure exhibited clearly weaker reactions. Moreover, lysozyme could distinctly be demonstrated in the cells of the esophageal epithelium. It can be concluded that a first line of defence mechanisms of the innate immune system contributes to maintaining a microbial homeostasis on the surface of the esophageal epithelium of domesticated mammals. The results are discussed in comparison to findings from studies on the human esophagus.     

云南省小型哺乳动物寄生恙螨群落种多度分布

目的了解云南省小型哺乳动物寄生恙螨种类和数量分布情况。方法选取云南省16个县（市）为调查点，现场用鼠笼加食饵诱捕小型哺乳动物（小兽），收集其耳廓和外耳道全部恙螨，用Hoyer’s液封片，制成玻片标本后，常规分类、鉴定。种多度分布采用Preston对数正态分布拟合。结果共捕获小兽6888只，其双耳部检获恙螨87416只，属3亚科21属192种。小板纤恙螨（Leptotrombidium scutellare）和中华纤恙螨（Leptotrombidium sinicum）为主要优势螨种。种多度分布趋势用Preston对数正态分布模型拟合较好，拟合优度为0．7975。结论云南省小型哺乳动物寄生恙螨群落的种多度关系呈对数正态分布，中等个体数量的恙螨种类占多数，个体数量很少的稀有种次之，个体数量很大的优势种类在群落内只是少数。     

Behavioral disturbances and hair cell loss in the inner ear following nitrile exposure in mice, guinea pigs, and frogs.

Several nitriles have been demonstrated to cause hair cell loss in the inner ear of the rat, but the susceptibility of other species to this toxic effect has not been investigated. Adult male Swiss mice were administered (po) control vehicle, cis-crotononitrile (2.75 mmol/kg), or 3,3'-iminodipropionitrile (IDPN, at 8, 16, and 24 mmol/kg), and the changes in vestibular function were assessed by behavioral endpoints. In addition, surface preparations of the vestibular sensory epithelia were examined for hair cell loss using scanning electron microscopy (SEM). IDPN, in a dose-dependent manner, and cis-crotononitrile induced both vestibular dysfunction and loss of hair bundles. Male Dunkin Hartley guinea pigs were administered IDPN (0, 1.6, 2.4, or 3.2 mmol/kg, ip), and their vestibular and auditory sensory epithelia were examined by SEM. The guinea pigs developed behavioral abnormalities indicative of vestibular dysfunction, with more overt effects observed in the animals treated with larger doses, and displayed a dose-dependent loss of hair bundles in both the vestibular and the auditory epithelia. Frogs (Rana perezi) were administered IDPN (0, 16, 24, or 32 mmol/kg, ip), and their sensory epithelia in the inner ear were examined by SEM. IDPN caused behavioral abnormalities indicative of vestibular dysfunction and loss of hair bundles. We conclude that some nitriles are thorough ototoxic compounds affecting hair cells in a wide range of species. This conclusion highlights the potential interest of this toxic effect and offers new animal models in which to decipher its basis.     

It is Time to Thoroughly Study the Effects of Mild Stress in Rodents, but also in Human Beings

Many experiments on the effect of mild stress on aging have been done in invertebrates, but not in mammals. Using mild stress to improve healthspan seems to be possible, because the few studies on humans which have been published appear to be promising. Particularly, one may wonder whether heat shocks could be of some use in therapy or as an integrated part of daily life of elderly people. However, the top priority is probably to study more thoroughly the effects of mild stress in rodents, and not only in invertebrates.     

康定县小型兽类调查报告

作者于1987、1988年在四川省康定县选择不同生境、不同海拔高度地区，采集小型兽类标本594只，经鉴定隶属于3目5科11属17种；并对不同生境小型兽类的组成与分布进行了描述。     

洱源县血吸虫病流行区小型兽类调查

目的：了解不同生境小兽的种群组成、分布和密度。方法：用鼠笼、鼠夹和电网捕鼠,并测定密度。结果：共采集标本１０３６只,隶属４目５科９属１４种。以褐家鼠、黄胸鼠和大足鼠为主要种类,分别占３３．０１％、２７．２２％和２２．６８％。夹夜密度居民区为１５．１２％,以褐家鼠为优势种;农耕区为１０．７３％,以大足鼠为优势种;果园为１２．６１％,以斯氏家鼠为优势种。结论：该地小兽种类多,密度高,部分种类可自然感染日本血吸虫     

Grass height and transmission ecology of Echinococcus multilocularis in Tibetan communities, China

Background Alveolar echinococcosis is a major zoonosis of public health significance in western China. Overgrazing was recently assumed as a potential risk factor for transmission of alveolar echinococcosis. The research was designed to further test the overgrazing hypothesis by investigating how overgrazing influenced the burrow density of intermediate host small mammals and how the burrow density of small mammals was associated with dog Echinococcus multilocularis infection. Methods The study sites were chosen by previous studies which found areas where the alveolar echinococcosis was prevalent. The data, including grass height, burrow density of intermediate host small mammals, dog and fox fecal samples as well as Global Positioning System （GPS） position, were collected from field investigations in Shiqu County, Sichuan Province, China. The fecal samples were analyzed using copro-PCR. The worms, teeth, bones and hairs in the fecal samples were visually examined. Single factor and multifactor analyses tools including chi square and generalized linear models were applied to these data. Results By using grass height as a proxy of grazing grass in the pasture led to lower small mammals＇ pressure in the homogenous pasture, this study found that taller burrow density （X2=4.670, P=0.031, coefficient=-1.570）. The Echinococcus multilocularis worm burden in dogs was statistically significantly related to the maximum density of the intermediate host Ochotona spp. （X2=5.250, P=-0.022, coefficient=0.028）. The prevalence in owned dogs was positively correlated to the number of stray dogs seen within a 200 meter radius （Wald X2=8.375, P=-0.004, odds ratio=1.198）. Conclusions Our findings support the hypothesis that overgrazing promotes transmission of alveolar echinococcosis and confirm the role of stray dogs in the transmission of alveolar echinococcosis.     

Is It or Isn't It? A Reexamination of the Anterior Orbital Glands of the Fat‐Tailed Dunnart Sminthopsis Crassicaudata (Dasyuridae: Marsupiala) and a Reevaluation of Definitions for the Harderian Gland

The anterior orbital glands of tetrapods, which include the Harderian and nictitans glands, can usually be differentiated either anatomically (nictitans gland is more anterior) or histochemically (Harderian gland secretes lipids). However, conflicting statements exist in the literature about the presence and identity of these glands. Two previous studies on Sminthopsis crassicaudata (Dasyuridae: Marsupiala) either failed to note any anterior ocular glands or used no histochemical analyses. This study reexamined the structure of the anterior orbital glands of S. crassicaudata. Histological, histochemical, and ultrastructural examination revealed three glandular units: two of which are located superficially in the nictitating membrane, the third lying deeper in the connective tissue. The ducts of these three glandular units all open onto the corneal aspect of the nictitating membrane. These cells contain mainly serous granules with sparse intracellular lipid droplets. The nomenclature of these structures depends upon the definition used. According to the anatomical definition, S. crassicaudata has two glands: anteriorly the nictitans and posteriorly the Harderian gland. In contrast, if the histochemical definition is used, there is only one gland, but its precise identity cannot be confirmed until the role of the lipid droplets is established. Moreover, the histochemical definition poses additional problems with respect to the mechanism of secretion, multiple secretions, and glandular plasticity. Finally, the unitary definition identifies one deeply subdivided gland with an anterior and a posterior lobe in S. crassicaudata. This last definition is broad enough to accommodate a wide level of anatomical variation in the anterior ocular glands of tetrapods. Anat Rec 293:1449–1454, 2010. © 2010 Wiley‐Liss, Inc.