Ultrastructural variations in the sweat glands of anhidrotic horses

The ultrastructure of sweat glands from the skin of free sweating horses was compared with that of glands from anhidrotic cases. Evidence of atrophied and abnormal sweat glands in the anhidrotic horses indicates that the condition involves progressive failure of the glandular mechanism of sweat production.     

Echocardiographic detection of an intact aneurysm in a horse

Two-dimensional real-time echocardiographic examination of a 3-year-old Thoroughbred gelding with pleuropneumonia revealed an intact aneurysm of the right sinus of Valsalva, which was confirmed at postmortem examination. The horse had no clinical signs associated with the aneurysm.     

A case of multiple epitrichial sweat gland ductal carcinomas in a horse

This case report describes a rare epitrichial sweat gland ductal carcinoma in a 14-year-old horse and is the first report of multiple carcinomas of this type in horses. Although several tumours developed, mostly on the distal extremities, over a 2-year period, the horse remained otherwise healthy. Topical treatment with imiquimod was successful for many of them.     

Characterisation of glycoproteins in the sweat of the horse (Equus caballus)

The two major polypeptides H (Mr 49,000) and L (Mr 33,000) of equine sweat have been purified by gel filtration and characterised by gel electrophoresis and compositional analysis. Both H and L are glycoproteins containing sialic acid, neutral sugars, N-acetylglucosamine and N-acetylgalactosamine, but the two polypeptides differ considerably in the extent of glycosylation. H and L also differ in amino acid composition, but both contain only low levels of sulphur containing amino acids and histidine. These glycoproteins may behave as surfactants.     

Neoplasms of the apocrine sweat glands in 44 dogs and 10 cats

Neoplasms of the apocrine sweat glands accounted for 2.0 per cent and 3.6 per cent, respectively, of all canine and feline skin neoplasms diagnosed during a period of three years. They occurred in dogs from six to 17 years of age of both sexes, and golden retrievers appeared to be predisposed; they occurred in cats from six to 17 years of age and there were no breed or sex predilections. In both species, the neoplasms were usually solitary and occurred anywhere on the body; they were nearly always carcinomas and histologically were usually of the solid type. There were no clinical measurements that made it possible to distinguish reliably between benign and malignant lesions. No distant metastases were recorded, even though 22.5 per cent of the canine carcinomas had invaded the lymphatic system.     

Distribution and numbers of mucous glands in the horse trachea

Horses commonly suffer from respiratory diseases associated with excess secretions in the airway lumen, some of which are presumably derived from airway mucous glands. However, these structures have been little investigated in the horse. Accordingly, we describe here the number, distribution and size of equine tracheal mucous glands, and compare the data with similar information for other mammalian species. Two types of gland acini were present. In the thick connective tissue, up to 400 microm beneath the epithelium, gland acini were grouped in thin sheets that, in cross-section, averaged 20 microm thick and were up to 4.0 mm in length. However, it is probable that most sheets had maximal diameters much less than 4.0 mm. Between 400 to 900 microm below the epithelium, the connective tissue was much more diffuse, and glands were larger and more globular. Gland volume in the ventral portion was approximately 1.7 microl/cm2 of mucosal surface, and approximately 1.1 microl/cm2 in the dorsal portion. Glands were somewhat more abundant between, rather than over, the cartilaginous rings, but the difference between the 2 locations was not marked. Mucous gland openings were small (20 microm diameter) and very unevenly distributed, generally occurring about 100 microm apart in longitudinal rows of about 5. Average frequency of openings in the ventral portions of 3 tracheas was approximately 1.0/mm2 of mucosal surface. The volume of individual glands was therefore approximately 17 nl. Although the frequency of gland openings in the horse trachea is similar to that for the tracheas of other large mammalian species, horse tracheal gland volume was only about 15% that of the other species. Therefore, the excess 'mucous' secretions seen in equine recurrent airway obstruction and other respiratory diseases are unlikely to be caused by comparatively high levels of airway mucous gland secretion. Instead, they may be caused mainly by hyperplasia of the mucus-producing cells of the surface epithelium or by vascular transudation.     

Adenocarcinoma of apocrine sweat glands in a mouflon (Ovis musimon).

A free-living mouflon (Ovis musimon) was presented with a mass on the left shoulder. At necropsy, multifocal, slightly protruding whitish spots were noted on the kidneys, and several lymph nodes were abnormal. Histologically, the mass was composed of epithelial cells arranged in tubular and tubulopapillary structures. The cytoplasm of the epithelial cells had numerous periodic acid-Schiff-positive and diastase-resistant granules. Ultrastructurally, the cytoplasm of the neoplastic cells contained numerous pleomorphic secretory granules and microvilli, which partially covered the luminal surface of the tumor cells. Metastatic foci were present in prescapular and mediastinal lymph nodes and kidneys. On the basis of histological and ultrastructural findings, this tumor was diagnosed as a tubulopapillary adenocarcinoma, arising from apocrine sweat glands of the skin.     

Rate of discharge and morphology of sweat glands in the perineal, lumbodorsal and scrotal skin of cattle

The rates of evaporation of moisture from the skin in the lumbodorsal, perineal and scrotal regions of cattle were measured in thermoneutral and high environmental temperatures. The rates of evaporation from the perineal and scrotal regions of heifers and bulls were significantly (P<0–001) greater than those from the lumbodorsal areas. The lumbodorsal rate of evaporation increased significantly (P<0·001) when cows and bulls were transferred from a thermoneutral to a hot environment and the rate of evaporation from the scrotum of bulls showed a similar increase; the rate of evaporation from the perineum of cows increased to a smaller extent (P<0·05) under the same conditions. The rate of evaporation from the perineum of cows reached a maximum on the day of oestrus but the stage of the oestrous cycle had no effect on the lumbodorsal rate of evaporation.     

夏季皖东牛与荷斯坦牛皮肤汗腺及其散热调节特征

为了探究夏季高温时皖东牛与荷斯坦牛皮肤组织形态和皮肤散热调节特征的差异,在30℃以上的夏日,选择皖东牛和荷斯坦牛母牛各4头,屠宰后采集颈部、肩部、背部、腹部、臀部和腿部6个部位的皮肤样本,通过HE染色切片分析皮肤的汗腺(SWG)与皮脂腺(SEG)的分布与形态,测定皮肤组织乙酰胆碱(ACh)浓度及乙酰胆碱转移酶(AChT)和酯酶(AChE)活力,采用RT-qPCR和Western blot检测皮肤组织乙酰胆碱M3受体(ACh M3R)、一氧化氮合酶(eNOs)及水通道蛋白5(AQP5)mRNA和蛋白的表达。结果:部位间比较,皖东牛与荷斯坦牛表皮厚度均为背部最厚,颈部最薄(P<0.05)。品种间比较,皖东牛平均皮肤厚度较高,平均表皮厚度较薄(P<0.05);汗腺密度与皮脂腺密度品种间无显著差异(P>0.05);皖东牛汗腺和皮脂腺的平均长度、直径、深度、体积均显著增加(P<0.05)。肩部、背部和臀部皮肤对比:夏季皖东牛和荷斯坦牛皮肤组织ACh浓度品种间无显著差异(P>0.05),部位间以臀部最高,肩部次之,背部最低(P<0.05)。ACh M3R和AQP...     

Effects of thermal stimulation on intracellular sodium, potassium and chlorine in the sweat glands of the cow, sheep and goat

The intracellular concentrations of electrolyte elements in the sweat glands of the cow, sheep and goat provide evidence of altered secretory activity upon thermal stimulation in the cow but give no indication of such change in the sheep and goat. The results support the view that increased secretory function contributes to the pattern of sweat output in the cow.     

Characterisation of Chlamydia psittaci isolated from a horse

This paper describes the isolation and characterisation of a strain of Chlamydia psittaci obtained from a nasal swab taken from a horse with serous nasal discharge. Initial isolation was achieved in cycloheximide-treated McCoy cell monolayers. Chlamydial inclusions stained by immunofluorescence either with a rabbit antiserum raised against C. psittaci or with a monoclonal antibody directed against the genus-specific lipopolysaccharide antigen were single and compact. They did not stain with iodine or with a monoclonal antibody reactive against Chlamydia trachomatis. The agent was re-isolated in the yolk sacs of embryonated hens eggs and designated N16. Identification of the agent was confirmed by electron microscopy. Unique plasmid DNA was prepared from a purified suspension of chlamydial elementary bodies (EBs), and analysed by electrophoresis through 1.0% agarose gels stained by ethidium bromide. This strain of C. psittaci grew relatively slowly in cycloheximide-treated McCoy cells, and the yield of elementary bodies during the course of one growth cycle was relatively low.     

Microsporum gypseum isolated from ringworm lesions in a horse

Abstract

Extract

Microsporum gypseum has a world-wide distribution in soil, and it is considered to be essentially a soil inhabitant that only occasionally parasitizes animals and man (Georg, 1959 Georg, L. K. 1959. Animal Ringworm in Public Health, 3–17. U.S. Dept. of Health, Education and Welfare, Public Health Service Publ..  [Google Scholar]).     

Quantification of the response of equine apocrine sweat glands to beta2-adrenergic stimulation.

The aim of the present study was to characterise the quantitative sweating response of the horse to beta2-adrenergic stimulation. The sweating responses of 6 horses to the randomised infusion of 8 different adrenaline concentrations (0.025, 0.05, 0.075, 0.1, 0.2, 0.4, 1.0 or 2.0 microg/kg bwt/min), was investigated. Sweating rate (SR) and skin temperature (TSK) on the neck (N) and gluteal region (G), and plasma adrenaline and noradrenaline concentrations were measured. Peak SR was approximately 15 (N) and approximately 9 g/m2/min (G) during infusion of both 1.0 and 2.0 microg/kg bwt/min adrenaline. Sweat produced per nmol/l plasma adrenaline peaked during the infusion of 0.075 microg/kg bwt/min adrenaline. Higher adrenaline infusion concentrations resulted in a progressive decrease in the amount of sweat produced per nmol/l plasma adrenaline and a plateau of 6 g/m2/(nmol/l) plasma adrenaline was reached for infusions between 1.0 and 2.0 microg/kg bwt/min. Peak SR were far lower than we have previously reported during exercise. There was no evidence of sweat gland fatigue or vasoconstriction during infusion, suggesting saturation of sweat gland beta2 receptors. We conclude that sweating in the horse is under dual control from a combination of hormonal and neural mechanisms.     

Effects of season and lower ambient temperature on the structure of the sweat glands in anhidrotic horses

Histological studies of the sweat glands of anhidrotic horses in the Hong Kong summer and under conditions of reduced thermal stress, both natural and controlled, were undertaken to determine if glandular regeneration occurs. Clinical data were collected for comparison with the histological results in each instance. Horses were assigned to one of three categories on the basis of the resulting change in the number of thin glandular profiles in a cooler environment. Group 1, which was classed as normal, had a low initial value, which was maintained. Group 2, typical of mild and moderately affected animals, had a high initial value, which fell markedly after as little as six weeks in the cool environment. Animals in Group 3, classed as severely affected, had a high initial value which remained high even after prolonged exposure to the cool environment. Light microscopical examination of the sweat glands in the heat, and after six weeks in a cool environment, provided a means of predicting the degree of anhidrotic severity and the potential for recovery in a cool climate. This was superior to clinical observation, although a diagnostic test based on glandular function is still required.     

Antimicrobial resistance in streptococcal species isolated from bovine mammary glands

Streptococcal species isolated from dairy cows with clinical mastitis were obtained from mastitis research workers in Florida, Louisiana, New York, Vermont, Washington, and West Virginia. Seventy-one streptococcal isolates were tested, including 39 strains of Streptococcus agalactiae, 21 strains of S dysgalactiae, and 11 strains of S uberis. The minimal inhibitory concentration of erythromycin, lincomycin, oxytetracycline, penicillin, spectinomycin, streptomycin, and tetracycline was determined for each isolate. Differences were not detected among strains with respect to geographic origin. None of the strains was resistant to penicillin. Lincomycin was the next most effective antimicrobial, with only 2 resistant strains of each streptococcal species. There were no differences among the streptococcal species with respect to resistance to either penicillin or lincomycin. Streptococcus uberis was more likely to be resistant to erythromycin than were S agalactiae and S dysgalactiae (P less than 0.02). Streptococcus agalactiae and S uberis had similar distributions for resistance to oxytetracycline, tetracycline, spectinomycin, and streptomycin. Strains of S dysgalactiae were more likely to have intermediate resistance to oxytetracycline and streptomycin than were strains of S agalactiae and S uberis, which were highly resistant to oxytetracycline and streptomycin (P less than 0.001). Differences were not detected among the streptococcal species with respect to resistance to spectinomycin. Resistance to multiple antimicrobials was observed in all streptococcal species tested. Although S dysgalactiae appeared to have a greater percentage of strains (73%) that were resistant to multiple antimicrobials than did S agalactiae (31%) or S uberis (45%), differences were not statistically significant.