Cell proliferation kinetics in the hair root matrix of dogs with healthy skin and dogs with idiopathic seborrhea

Cell proliferation kinetic values were established for the hair root matrix of primary anagen follicles of 14 Beagles and 4 Cocker Spaniels with healthy skin and 9 Cocker Spaniels with primary idiopathic seborrhea. Indices were established by intradermal pulse labeling with tritiated thymidine, followed by cutaneous biopsy and autoradiography. The hair root matrix cell labeling index was 23.4 +/- 3.5% for Beagles, 24.4 +/- 4.0% for healthy Cocker Spaniels, and 24.9 +/- 4.3% for seborrheic Cocker Spaniels. These values indicate a rapidly proliferating cell population. Differences among these cell kinetic data for the 3 groups of dogs were not statistically significant. Although significant cell kinetic differences have been reported for other epidermal structures (interfollicular epithelium, upper hair follicle external root sheath, sebaceous glands) in seborrheic Cocker Spaniels, proliferation of hair root matrix cells apparently remains unaffected.     

光周期对于绒山羊毛囊干细胞激活的影响

为了延长绒山羊毛囊兴盛期,提高羊绒产量,本试验通过人工缩短内蒙古阿尔巴斯型绒山羊的日照时间,利用组织切片技术对比人工短光照和自然光照周期下绒山羊皮肤组织形态变化,利用免疫组织化学方法研究毛囊细胞增殖及相关信号通路重要蛋白的表达。结果显示,人工短光照周期下绒山羊毛囊细胞增殖强烈,干细胞标记角蛋白15（cytokeratin 15,K15）阳性信号大量分布于外根鞘,β-catenin信号活跃表达于毛母质及根鞘,毛囊提前进入兴盛期;而自然光照周期下绒山羊毛囊仍停留在休止期,相应蛋白信号表达较弱。综上表明,短日照对毛囊生长具有明显的促进作用,人工短光照周期可以提前激活毛囊干细胞,使其提前进入兴盛期,引起多种毛囊生长相关蛋白的表达。     

Effects of Photoperiod on Stem Cells Activation in Cashmere Goat Hair Follicles

In order to extend the anagen of cashmere goat hair follicles and increase the production of cashmere,this study was performed with artificially shorten the daylight time among Arbas White cashmere goats. Skin tissue sections from cashmere goats were collected to compare the morphologic changes between artificial daylight and natural daylight,and immunohistochemical method was used to study the hair follicle cell proliferation and important protein expression in related signaling pathways. The results showed that strong cell proliferation occurred in cashmere goat hair follicle cells during artificial daylight,plenty of cytokeratin 15 (K15) positive signals were distributed in the outer root sheath,β-catenin protein was actively expressed in hair matrix and root sheath, indicating that the hair follicles were in the anagen growth phase;Meanwhile,cashmere goat hair follicles under natural daylight were in telogen with weak signals. Above all prove that short photoperiod played an important role in promoting hair follicle growth,the artificial short photoperiod could change hair follicle growth cycle and make hair follicles earlier enter to the anagen growth phase,causing a variety of typical gene expressions during hair follicle growth.     

Comparison of hair follicle histology between horses with pituitary pars intermedia dysfunction and excessive hair growth and normal aged horses

Background –  Pituitary pars intermedia dysfunction (PPID) in older equids is commonly recognized by a long hair coat that fails to shed. Objective –  The aim of this study was to compare hair follicle stages in PPID‐affected horses with excessively long hair coats with the stages of normal aged horses (controls) and to compare hair follicle stages in PPID‐affected horses after 6 months of treatment with pergolide mesylate with those of control horses. Animals –  Eight PPID‐affected horses and four normal, age‐matched, control horses. Methods –  Skin biopsies were collected from the neck and rump of PPID‐affected and control horses. A diagnosis of PPID was established based on hair coat changes and supportive overnight dexamethasone suppression test results. Skin biopsies were repeated after 6 months of treatment with pergolide. The number of hair follicles in anagen (A) or telogen (T) was counted for each skin biopsy using transverse sections. Results –  Pretreatment biopsies had a greater percentage of A follicles (neck 96%, rump 95%) and a lower percentage of T follicles (neck 4%, rump 5%) in PPID‐affected horses than in control horses (A, neck 15%, rump 25%; and T, neck 85%, rump 75%). After treatment with pergolide, all PPID‐affected horses had improved shedding, and the percentages of A follicles (neck 69%, rump 70%) and T follicles (neck 31%, rump 30%) were not different from untreated control horses (A, neck 68%, rump 82%; and T, neck 32%, rump 18%). Conclusions –  These findings document that excessive hair growth (hypertrichosis) in PPID‐affected horses is due to persistence of hair follicles in A. Furthermore, treatment with pergolide improved shedding and reduced the percentage of A follicles in PPID‐affected horses.     

Influence of inflammation and coat type on oestrogen receptor immunohistochemistry

The purpose of this study was to evaluate oestrogen receptor alpha staining in a variety of breeds and skin conditions. The influence of inflammation and coat type on the presence and intensity of oestrogen receptor alpha staining was evaluated. Approximately 1700 haematoxylin and eosin (H&E)-stained slides of skin biopsies were screened for presence of small hair bulbs. Slides from 94 cases were submitted for oestrogen receptor alpha immunohistochemistry. H&E-stained skin biopsy tissues were examined for inflammation and hair follicle stages. Oestrogen receptor alpha staining characteristics of telogen follicles, flame follicles, large anagen bulbs, small hair bulbs and early anagen hairs (capped bulbs) were recorded. To assess the influence of inflammation and coat type on oestrogen receptor staining of hair follicle types, chi-square tests, Fisher's exact tests and logistic regression models were performed. Slides were classified as inflammatory (65) and noninflammatory (29). There were no statistically significant differences in oestrogen receptor staining when comparing inflammatory to noninflammatory skin biopsies or skin biopsies from dogs with different coat types. A subset of 13 noninflammatory biopsies from alopecic skin was identified. There was a statistically significant increase in the number of flame follicles in this subset as compared to all others. Comparison of oestrogen receptor staining of hair follicle types from these biopsies and all other biopsies revealed a statistically significant increase in the number of mature telogen hair follicles stained in this subset. No statistical difference in staining of early follicle stages was noted. Therefore, the oestrogen receptor is unlikely to be the controlling factor for the transition from telogen to anagen in the dog.     

Experimental infection of red foxes (Vulpes vulpes) with Sarcoptes scabiei var. vulpes

Two of 3 red foxes became experimentally infected with Sarcoptes scabiei v. vulpes isolated from a naturally infected wild fox. The first clinical sign was seen after 10 days. After 30 days hairless patches were observed on the back of one of the foxes while general hair loss continued slowly. On the other fox the only macroscopical changes was tangling of the hair. The foxes died after 67 and 94 days, respectively. Both foxes were anaemic and in very poor condition. Scratching was seen in only 1 of the foxes.     

Histology of the hair cycle in male beagle dogs

A detailed histologic study of the hair follicles of male Beagle dogs was made to determine changes in microscopic structure associated with the three stages in the hair cycle. Observed changes are that the bulbs of hair follicles in anagen are more closely associated with adipose tissue than they are in telogen. This is due to the deeper penetration of the follicles into the subcutaneous tissue during anagen. The hair germ cells of telogen were presumed to arise from the stratum basale of the matrix cells rather than from the outer root sheath cells. During telogen, the dermal papilla is separated from the club hair, but remains in close proximity to it. There is no connecting stalk as is reported for other animals.     

Studies of a naturally occurring molybdenum-induced copper deficiency in the yak

The clinical signs of a disorder known locally as "shakeback disease" in yaks in the North of the Qing Hai-Tibetan Plateau of China were defined: they included emaciation, unsteady gait, a 'shivering' back and deprived appetites. Coat colour was not affected. The mineral composition of soil and forages, and samples of blood and hair from yaks in affected ranches in this region were compared with those of 20 samples from unaffected areas. The mean concentration of molybdenum (Mo) in soil and forage was 4.85+/-0.21 and 4.96+/-0.25 microg/g (dry matter), respectively; the mean copper (Cu) to Mo ratio in the forage was only 1.34+/-0.36 compared to 8.12+/-1.31 for unaffected areas. The mean concentrations of Cu in blood and hair from the affected yaks were 0.29+/-0.17 and 3.51+/-1.12 microg/g, respectively, compared with 0.85+/-0.24 and 6.42+/-1.21 microg/g, for controls. The highest value for Cu in the blood of affected yaks was 0.58 mug/g and the lowest 0.03 microg/g (the corresponding highest values for unaffected yaks were 1.03 mug/g, the lowest 0.56 microg/g). There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. The Cu deficiency in yaks was most severe during pregnancy and lactation, but oral administration of copper sulphate prevented and cured the disease. We conclude that "shakeback disease" of yaks in this region is probably caused by a secondary Cu deficiency, mainly due to the high Mo content in soils and forage.     

辽宁绒山羊2品系皮肤毛囊周期性变化的比较研究

皮肤切片采用HE染色方法,对辽宁绒山羊常年长绒型品系和季节长绒型品系皮肤表皮厚、真皮厚、次级毛囊和初级毛囊深度、密度,次级毛囊和初级毛囊毛球宽度,S／P值等作了详细统计观察,从形态学方面研究了辽宁绒山羊皮肤毛囊在1年内的变化规律。结果表明：两品系辽宁绒山羊毛囊的兴盛期为4～10月,退行期为11～12月,休止期为1～3月,持续时间分别为7、2、3个月。兴盛期经历时间最长,退行期最短。但在毛囊的退行期,因为大多数毛囊的活性还很高,因此在退行期绒毛仍在生长,特别是在退行前期（10、11月份）还是绒毛的快速生长期。     

A hair abnormality in Abyssinian cats

An abnormality of the hair shaft of the whiskers and guard hairs of Abyssinian cats, consisting of an onion-shaped swelling, usually situated at the tip of the hair but occasionally at other sites along the hair shaft, is reported. Where the abnormality occurs in the guard hairs it imparts a rough, brittle and lustreless appearance to the coat. Microscopically the epidermis, dermis and hair follicles and appendages appear normal. The condition has been seen in two Abyssinian cats in Denmark and one in Australia.     

Expression analysis of the type I keratin protein keratin 33A in goat coat hair

The coat of a goat, like that of many mammalian species, consists of an outer coat of coarse hairs and an under coat of fine, downy hairs. The coarse guard hairs are produced by primary follicles and the finer cashmere hairs by secondary follicles. We previously reported that hair keratins are components of cashmere hair, and proteomic analysis revealed that their expression is elevated in winter coat hair. To determine detailed characterization, we have cloned keratin 33A gene, a major highly expressed keratin in winter, and then analyzed the expression of goat hair coat. By Western analysis, we detected that keratin 33A protein is expressed only in hair coat among the various goat tissues. Moreover, the expression level in winter has increased in cashmere high‐producing Korean native breed, whereas the expression levels between summer and winter had not changed in cashmere low‐producing Saanen. In addition, by immunohistochemistry we determined that keratin 33A is localized in the major cortex portion of cashmere fiber. These results confirm that keratin 33A is a structural protein of goat cashmere hair fiber.     

北极狐和貉毛纤维显微结构的研究

为了区别北极狐和貉毛皮，采用哈氏切片法快速制取北极狐、南貉和北貉皮毛纤维横切片进行毛纤维组织结构观察。观察发现，貉毛皮的绒毛鳞片翘角大，呈刺状伸出毛干外，鳞片高度大；而北极狐绒毛的鳞片紧贴毛干，呈环形排列。因此，对于北极狐皮和貉皮的鉴别可通过其毛纤维的显微结构进行区分。     

内蒙古绒山羊与辽宁绒山羊皮肤毛囊周期性变化的比较研究

对内蒙古阿尔巴斯白绒山羊和辽宁绒山羊皮肤及毛囊的组织学周期性变化作了比较研究，结果表明：表皮生发层细胞从3月份开始活动并向下延伸，此时毛囊也开始重建，绒山羊毛囊8-9月份进入兴盛期，12月份进入退行期，2-3月份为休止期。它们进入兴盛期和持续的时间不同，初级毛囊除毛球宽外，其它各性状阿尔巴斯白绒山羊均大于辽宁绒山羊，而次级毛囊各性状辽宁绒山羊都大于阿尔巴斯白绒山羊，在大多数月份二者差异显著。毛囊深、密度、S／P、毛球宽和生长期是影响产绒量的因素。     

初生水貂皮肤毛囊发育组织学观察

为了解水貂皮肤毛囊发育的变化规律,本试验采集0～6周龄初生的美国短毛黑公水貂的背中部皮肤样品,用HE染色法制备组织切片,在显微镜下观察其皮肤毛囊结构及变化规律。结果发现,水貂的皮肤在出生前就已经基本发育完成,初级毛囊、次级毛囊的毛干具有髓质;水貂出生时可见初级毛囊而无次级毛囊,初级毛囊的密度随周龄的增加而增加,于4周龄后降低,初级毛囊在水貂4周龄后不再发育或很少发育, 4周龄时可见次级毛囊,次级毛囊随水貂体表的增长毛密度增加,且在水貂出生后大量发育。水貂6周龄时S/P值为2.95±0.23,次级毛囊仍将大量发育。水貂背中部表皮呈先增厚后变薄的变化,真皮随着周龄的增加而增厚;初级毛囊、次级毛囊随周龄的增加而加深。     

Study on the prevalence of Toxoplasma gondii and Neospora caninum and molecular evidence of Encephalitozoon cuniculi and Encephalitozoon (Septata) intestinalis infections in red foxes (Vulpes vulpes) in rural Ireland

Thoracic fluid (pleural fluid and clotted blood) from 206 foxes were examined for antibodies to Toxoplasma gondii and 220 thoracic fluid samples were tested for Neospora caninum antibodies using indirect immunofluorescent antibody tests (IFAT). A total of 115 (56%) and six (3%) foxes had antibodies to T. gondii and N. caninum, respectively. The brains from 148 foxes were examined for histological lesions and pathological changes suggestive of parasitic encephalitis were observed in 33 (22%). Two thirds of these foxes had antibodies to T. gondii and one fox had antibodies to both T. gondii and N. caninum. PCR assays carried out on DNA extracted from the 33 brains with histological lesions were negative for N. caninum but one of the brains was positive for T. gondii. Microsporidian DNA was also amplified from the brains of two of these foxes. Sequencing these amplicons revealed 100% homology with Encephalitozoon (Septata) intestinalis in one fox and Encephalitozoon cuniculi in the second fox. This is the first report of Encephalitozoon infections in wildlife in Ireland.     

Seasonal Moulting in Adult Male Raccoon Dog (Nyctereutes procyonoides)

Abstract

Seasonal moulting was studied by quantitative histology and external observations in adult male raccoon dogs. Moulting of the underfur hairs is characterized by a heavy loss of old winter hair in spring and an intensive growth of new winter hair in autumn. Only few mature and growing underfur hairs were found in the hair cover in summer. The new intermediate and large guard hairs started to develop in April and May. All the new guard hairs had developed by the end of June. About 7 and 3.5 months were needed for the growth of new winter guard and underfur hairs respectively. At the end of November the winter fur was mature. The bundles with an intermediate guard hair contained more underfur hairs than the bundles with a large guard hair in the mature winter fur. The thickness of dermis and the grade of skin colour peaked in the autumn moult, indicating a close relation to the activity of hair follicles.     

The effects of thyroid hormones on the skin of beagle dogs

The effects of hypothyroidism on canine skin were determined by comparing morphologic, morphometric, and hair cycle differences in skin biopsy samples from 3 groups of age- and gender-matched Beagle dogs: (1) euthyroid dogs; (2) dogs made hypothyroid by administration of 131I; and (3) dogs made hypothyroid and maintained in a euthyroid state by treatment with synthetic thyroxine. After 10 months of observation, there was slower regrowth of hair 2 months after clipping in the untreated-hypothyroid dogs. Untreated-hypothyroid dogs had a greater number of follicles in telogen and fewer hair shafts (ie, a greater number of hairless telogen follicles) than did the control group. The control dogs had a greater number of telogen follicles but the same number of hair shafts as the treated-hypothyroid group. Treated-hypothyroid dogs had the greatest number of follicles in the growing stage of the hair cycle (anagen). This study suggests that, at least in Beagles, induced hypothyroidism does not affect the pelage as dramatically as has been described in naturally occurring disease. This is because normal Beagles retain hair shafts in follicles for long periods, and the alopecia of hypothyroidism appears to evolve slowly because of the prolongation of this haired telogen stage. The evaluation of thyroxine-treated hypothyroid dogs demonstrates that thyroid hormone supplementation of Beagle dogs with induced hypothyroidism stimulates hair growth.     

Ultrastructure and stereology of leukocytes and platelets of normal foxes and a fox with a Chediak-Higashi-like syndrome

Peripheral blood leukocytes and platelets from five normal foxes (Vulpes vulpes) and a fox with phenotypical characteristics of Chediak-Higashi syndrome (CHS) were examined by electron microscopy. Lymphocytes, monocytes, neutrophils, eosinophils, and platelets from the affected fox contained giant membrane-bound granules that resembled lysosomes. In eosinophils and neutrophils from the affected fox and a normal fox, relative cell volume occupied by granules and number of granules per unit area were calculated. Relative cell volume occupied by granules was the same in both foxes, but there were significantly fewer granules per unit area in the affected fox. This result is consistent with the idea that the giant granules arose from fusion of pre-existing, normal-sized granules, as occurs in CHS. In platelets from the affected fox, no osmiophilic granules were seen. Our findings agree with those from studies of CHS-affected blood cells in other species.