山羊毛囊干细胞的分离及体外培养

试验采用2．4U／mL Dispase酶消化和机械切割法分离毛囊隆突部,经胰酶（0．5mg／mL胰酶＋0．2mg／mL EDTA）消化从山羊耳部皮肤分离得到的毛囊干细胞,然后进行形态学观察、细胞生长曲线测定、克隆形成率及免疫组化染色检测,并对毛囊干细胞的基础培养基进行了筛选。结果表明：DMEM／F12是一种适合毛囊干细胞体外增殖培养的培养基;在以DMEM／F12为基础培养液的培养体系中细胞可传代至19代。     

羊驼毛囊干细胞分离、培养与鉴定

采用0.2%中性蛋白酶Ⅱ和0.25%胰酶∶0.02%EDTA(1∶1)两步酶消化法从羊驼背部皮肤分离得到羊驼毛囊干细胞。用无血清角质细胞培养基(K-SFM)培养进行形态学观察、细胞生长曲线克隆形成率及免疫组化染色检测。结果显示,细胞生长曲线表明,不同代次毛囊干细胞接种前3d生长缓慢,4⁶d进入倍增期,有无限增殖的趋势,所分离的羊驼毛囊干细胞具备毛囊干细胞特征(体积小、立体感强),呈现未分化特征;CK19、CK15、β1-integrin和CD34免疫组化染色阳性;第3、5、7、9代克隆形成率分别为(32.7±2.27)%、(47.0±3.46)%、(46.3±3.18)%和(43.3±3.76)%。结果表明,用两步酶消化法成功分离获得羊驼毛囊干细胞,无血清角质细胞培养基(K-SFM)可使羊驼毛囊干细胞体外维持未分化状态并传代至12代。     

羊驼毛囊干细胞分离、培养与鉴定

采用0．2％中性蛋白酶Ⅱ和0．25％胰酶：0．02％EDTA（1：1）“两步酶”消化法从羊驼背部皮肤分离得到羊驼毛囊干细胞。用无血清角质细胞培养基（K-SFM）培养进行形态学观察、细胞生长曲线克隆形成率及免疫组化染色检测。结果显示,细胞生长曲线表明,不同代次毛囊干细胞接种前3d生长缓慢,4～6d进入倍增期,有无限增殖的趋势,所分离的羊驼毛囊干细胞具备毛囊干细胞特征（体积小、立体感强）,呈现未分化特征;CK19、CK15、81-integrin和CD34免疫组化染色阳性;第3、5、7、9代克隆形成率分别为（32．7±2．27）％、（47．0±3．46）％、（46．3±3．18）％和（43．3±3．76）％。结果表明,用“两步酶”消化法成功分离获得羊驼毛囊干细胞,无血清角质细胞培养基（K—SFM）可使羊驼毛囊干细胞体外维持未分化状态并传代至12代。     

毛囊干细胞研究进展

文章阐述了毛囊干细胞的定位、表面标记及分化调控,同时阐述了毛囊干细胞在毛发再生、创面愈合、决定动物皮毛颜色基因程序重调及其它方面的应用。对实现毛发再生,促进皮肤损伤后功能与结构的完全修复具有重要意义。     

Immunohistochemical detection of p27 and p21 proteins in canine hair follicle and epidermal neoplasms

Trichoblastomas, trichoepitheliomas, and squamous cell carcinomas in the skin of dogs were analysed by immunohistochemistry for the nuclear expression of p27, p21 and proliferating cell nuclear antigen (PCNA). High levels of p27 were present in trichoepitheliomas and trichoblastomas compared with squamous cell carcinomas. Detectable p21 was found in trichoepitheliomas and squamous cell carcinomas, but trichoblastomas had low level of p21 nuclear reactivity. Low levels of PCNA were detected in trichoepitheliomas and trichoblastomas compared with squamous cell carcinomas. The results suggested that nuclear p27 acts as a cyclin-dependent kinase (CDK) inhibitor in trichoepitheliomas and trichoblastomas. Nuclear p21 expression is involved in the induction of epithelial differentiation and seems to be unrelated to CDK inhibition.     

In vitro metabolism of progesterone by canine hair follicle cells

Dermal papilla cells (DPC) and dermal fibroblasts (DFB) derived from hair follicles from two different body sites (head, flank) of four male, castrated beagle dogs were incubated for 24 h with radioactive progesterone (P4). Thin-layer chromatography was used for separation and autoradiography for identification of the radioactive metabolites. In DFB the main metabolites were cortisol and 4-pregnene-11beta-ol-3,20-dione, whereas in DPC they were 5alpha-pregnane-3,20-dione and cortisol. The highest percentage of metabolism of P4 was found in DFB of the head. Smaller amounts of other metabolites were found in both cell types of both locations.     

Thyroid tumours in the dog

The clinical, radiological and histopathological features of 30 thyroid tumours in the dog are described. Ten tumours were considered suitable for surgical removal and in a follow-up period of between 14 and 36 months five dogs were still alive.     

In vitro metabolism of dehydroepiandrosterone and testosterone by canine hair follicle cells

The metabolism of radioactive dehydroepiandrosterone (DHEA) and testosterone was studied in dermal papilla cells (DPC) and dermal fibroblasts (DFB) derived from hair follicles from two different body sites (head, flank) of four male, castrated beagle dogs. Thin layer chromatography was used for separation, and autoradiography for identification of the radioactive metabolites. DHEA was metabolized mainly to 11 alpha-OH-testosterone and only to a minor extent to 11 alpha-OH-androstenedione and another unidentified metabolite. The highest percentage of metabolization of DHEA was found in DFB of the head. Testosterone was metabolized only to a minor extent (less than 10%) to 5 alpha-dihydrotestosterone and epiandrosterone and there was no significant difference between either the two cell types or the two locations. These results clearly show that the metabolization of androgens in canine DPC and DFB is different from that observed in cells from the human hair follicle.     

The phase of hair growth in hypothyroidism in the dog

The stage of hair growth which predominated in dogs not affected with hypothyroidism appeared to be breed-dependent. For example, in boxers, Labradors and collies, the resting stage (telogen) predominated, whereas in West Highland White terriers and cairn terriers the active stage (anagen) predominated. However, even in pet dogs kept mainly indoors, the proportion of hairs in anagen tended to increase during the winter months.In dogs affected with hypothyroidism, the proportion of hairs in anagen or telogen in members of a particular breed was the same as in the normal dogs of the breed. From this, it appeared that breed was more influential than hypothyroidism in determining the predominant phase of hair growth.     

The effects of thyroxine on hair growth in the dog

The effects of orally and topically administered thyroxine on hair growth were studied in normal, intact, cross-bred male dogs maintained under the same controlled conditions of temperature and photoperiod. It was found that, irrespective of the route of administration, thyroxine produced an increase in both the rate of hair growth and in the number of hair follicles entering the anagen phase of the hair cycle. With orally administered thyroxine, the changes in hair growth were most marked in the flank region.     

The surgical management of bone-involved oral tumours in the dog

A total of 28 dogs bearing bone-involved tumours of the oral cavity underwent radical excision procedures including premaxillectomy, mandibular symphysectomy and removal of the horizontal body or vertical ramus of the mandible. Subsequent return to normal feeding was rapid and long-term prehensile and masticatory function was considered to be good with prosthetic reconstruction necessary in only one case. Amongst the 23 malignant tumours in this series the actuarial survival rate at twelve months was markedly improved in the case of the squamous cell carcinoma and osteosarcoma over that for conventional treatment techniques. No significant improvement was seen in the cases of fibrosarcoma. All five dogs undergoing surgery for benign tumours are surviving tumour free. Radical surgical excision is a practical approach to the management of otherwise complex mandibular and premaxillary tumours providing good tumour-free function and improvement in prognosis for certain histological types.     

Determination of the depth of excision using a dermatome (Aesculap) to export all hair follicle bulbs from a donor site in the dog

The aim of the study was to determine the depth of excision using a dermatome to excise all hair follicle bulbs from the donor site. Partial-thickness skin samples of different depth, ranging from 0.4 to 1 mm, were excised using a dermatome (Aesculap) from the dorsal aspect of the trunk of the dog. Biopsies, using a 6-mm biopsy punch, were performed in the centre of each donor site and excised sample. They were processed routinely for histological examination and the aspect of the hair follicles was observed. Split-thickness skin grafts of >or=0.7 mm deep performed with a dermatome contain the entire hair follicle.     

Nerve sheath tumours in the dog and cat

Schwannomas were diagnosed in twelve dogs and five cats at Massey University Small Animal Clinic and Hospital over a 15-year period (1977-92). A further two feline cases were reported at the Batchelar Animal Health Laboratory. In six dogs, the tumour involved nerves of the brachial plexus. Clinical signs observed in these dogs were forelimb lameness, muscle wasting and pain on movement of the affected limb or neck. Hindlimb paresis was observed in two dogs. Surgical excision of the brachial plexus tumour was attempted in one dog, leading to an 8-month remission of signs. In one dog, the tumour involved the sacral nerves, and in two dogs the cranial nerves were affected. Three dogs had skin nodules. Seven of the twelve affected dogs were destroyed. In five cats, the tumours developed on the carpus, tarsus or interdigital area of a forelimb or hindlimb as a slowly developing nodular lesion. In the other two cats, the site of the tumour was the flank and the lateral thigh respectively. Surgical excision of the tumour was successful in three cats.     

Colonisation status of Malassezia pachydermatis on the hair and in the hair follicle of healthy beagle dogs

Hair and hair follicle carriage of Malassezia pachydermatis was studied in 12 healthy beagle dogs. The yeast was isolated from hair clipped from the lip region at 13 sites in nine dogs but was less frequently recovered from the interdigital spaces on the forefeet and from two sites on the trunk. Population sizes at the lip were significantly greater (P < 0.01) than those at other sites. Skin biopsy specimens were obtained from the same sites and epidermal and follicular tissues dissected following immersion in 1 M CaBr(2). Epidermal carriage of M. pachydermatis was identified in nine biopsy specimens taken from five dogs. Hair follicle carriage was identified in five skin specimens (four foot, one lip) from three dogs. This study indicates that M. pachydermatis is readily recovered from the distal hair in healthy dogs and that hair follicle carriage is infrequent or that populations are low at that site.     

Primary and secondary bone tumours in the dog

During a 14-year period (January 1962 to December 1975), 394 primary and secondary tumours or tumour-like lesions affecting bones were diagnosed in the dog. The most frequently occurring tumour was osteosarcoma (183, 46.5%), followed by chondrosarcoma (forty-four, 11.2%), squamous cell carcinoma (thirty-nine, 10%), fibrosarcoma (thirty-one, 7.8%), multiple myeloma (fourteen, 3.6%), haemangiosarcoma (fourteen, 3.6%), malignant melanoma (thirteen, 3.3%), synovioma (nine, 2.3%), lymphosarcoma (eight, 2.0%), cartilage analogue of fibromatosis (seven, 1.8%), adaman-tinoma (five, 1.3%), osteocartilaginous exostosis, ossifying fibroma, rhabdomyosarcoma (four each), polyostotic cyst, haemangiomatosis (three each), odontoma, tumoral calcinosis (two each), and osteoma, chondroma, desmoid fibromatosis, and malignant mesenchymoma (one each).
Of these, desmoid fibromatosis, malignant mesenchymoma, and haemangiomatosis have not been previously reported in the dog.