Presence Of Sweat Glands Research Articles

Factors determining sperm fertility

The purpose of the work is to to systematize scientific data on factors affecting sperm fertility. Sperm fertility is the ability of a sexually mature organism to reproduce offspring. It is determined by parameters such as sperm motility and the quantity of normal and pathological sperm forms in the ejaculate. The fertility of male producers is acquired in stages: spermatogenesis occurs at the beginning, then the spermatozoa mature in the epididymis. The epididymis plays a significant role in making sperm fertile. Maturation occurs due to a complex of substances produced by the epididymis, and the full maturation of spermatozoa occurs in the genital tract of the female. Thus, fructose, produced by the vesicular glands, affects the fertility of animals. Another substance found in seminal plasma is citric acid, which takes part in the acrosomal reaction. Fertility is influenced by such factors as: the age of the animal, breed, the health of the male's reproductive system, heat stress and others. For instance, as animals age, the number of pathological sperm forms increases in the ejaculate, and their motility decreases. The same happens in cases of inflammatory diseases of the male reproductive system. Changes in the qualitative characteristics of sperm were recorded among Simmental and red breeds, as well as Holstein-Frisian and Jersey breeds. Prolonged or severe heat stress can also have a negative impact on fertility, despite the presence of compensatory mechanisms. These mechanisms are maintained by the presence of sweat glands in the scrotum, which are innervated by sympathetic nerves, as well as a reflex arc between the scrotum and the respiratory center. When the scrotum's temperature rises, respiratory rate increases, facilitating cooling. Furthermore, sperm activity can vary depending on the season. In animals with seasonal reproductive activity, sperm fertility parameters are better during the breeding season.In summary, sperm fertility is a multifactorial process, the success of which is mainly due to the health of the male reproductive system and the presence of many compensatory and adaptive mechanisms.

Histological Assessment of Cutaneous Acute Graft-Versus-Host Disease in a Preclinical Swine Model of Hematopoietic Cell Transplantation and Vascularized Skin Flap Tolerance

Abstract 1894Graft-versus-host disease (GVHD) remains a frequent complication of hematopoietic cell transplantation with skin being a principal target organ. Murine models have provided some insight into the mechanisms of this complex disease process. However, mouse skin differs from human skin, and results of studies in rodents may not translate well to the clinic. Miniature swine is a well-recognized animal model for preclinical studies of skin including dermal toxicology, transdermal drug delivery and wound healing. Unlike skin of rodents, dogs or non-human primates, porcine skin is similar to human skin in terms of structure of epidermal rete ridges (Figure 1A), hair follicle structure and density, and presence of sweat glands and subcutaneous fat.We have developed a miniature swine model of haploidentical hematopoietic cell transplantation that results in stable stem cell engraftment, hematopoietic chimerism and donor skin flap tolerance without GVHD. Swine leukocyte antigen (SLA)ad animals receive 100cGy total body irradiation and T cell depletion using porcine CD3 immunotoxin prior to cytokine mobilized peripheral blood hematopoietic cell transplantation from a haploidentical SLAac donor. Daily cyclosporine is administered at doses adjusted to maintain serum levels between 400–800 ng/ml starting one day prior to transplantation and continued for 30 days with taper until day 45.Mixed hematopoietic cell chimerism persists in these animals and donor vascularized skin flaps are accepted without the need for maintenance immunosuppression regardless of whether they are placed at the time of hematopoietic cell transplantation or greater than 100 days later. Despite the initial resistance to GVHD in this model, acute cutaneous GVHD could be induced through infusion of a high dose of donor leukocytes (DLI) including 15 million donor T cells/kg recipient body weight administered 463 days post hematopoietic cell transplantation and 314 days post vascularized donor skin flap transplantation. Conversion to full donor hematopoiesis was observed between 3–4 weeks post DLI. At this time a mild skin rash was evident in both donor and host skin which appeared to progress specifically within host skin. The presence of both donor and host skin on a tolerant animal whose peripheral blood consists of a mixture of both donor and host derived hematopoietic cells provides a novel model to evaluate specific targets of acute GVHD.In this study we assess histologically the manifestations of acute GVHD in both donor and host skin and compare it to typical histological manifestations of acute GVHD observed in patients. Specifically, recipient skin developed superficial lymphoid infiltrates that progressed to confluence along the dermal-epidermal junction by day 21. These infiltrates were associated with intraepidermal migration, prominent basal cell layer keratinocyte apoptosis, and satellitosis virtually indistinguishable from grade 3–4 human cutaneous acute GVHD (Figure 1B). Superficial portions of hair follicles were involved, as also seen in human disease. Of interest, mild disease was detected in the donor skin grafts by day 62 post-DLI, where selective lymphoid infiltration in the tips of the epidermal rete ridges and in association with target cell apoptosis/satellitosis was documented, a finding remarkably similar to early targeting events in humans.These findings emphasize the value of the porcine model for translational studies of cutaneous GVHD. Preliminary data suggest differences in cellular targeting between recipient and donor skin whereby the latter may be triggered by the presence of chimeric recipient-derived hematopoietic elements that have populated donor grafts. Further studies are now possible to explore the effector-target cell interactions in this clinically-relevant model of human cutaneous GVHD. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Ectodermal dysplasia with true anodontia

The hereditary condition known as ectodermal dysplasia is characterized by the absence or defect of two or more ectodermally derived structures. The most commonly observed forms of ectodermal dysplasia are the hidrotic and hypohidrotic types; discrimination is based on the absence or presence of sweat glands. A case of 8-year-old male child with hypohidrotic ectodermal dysplasia with complete anodontia of primary as well as secondary dentitions is presented. The child had a short stature, low intelligent quotient (I.Q.,), and was underweight. The patient experienced episodes of high fever, was intolerant to heat, and did not sweat. He exhibited smooth and dry skin, sparse light-colored eyebrows. Dental clinicians can be the first to diagnose ectodermal dysplasia due to the absence of teeth.

Electrical Characterization of Acupuncture Points: Technical Issues and Challenges

Acupuncture points are frequently described as having distinct electrical properties. These properties include increased conductance, reduced impedance and resistance, increased capacitance, and elevated electrical potential compared to adjacent nonacupuncture points. Commercial electrodiagnostic devices have used this assertion as a means to localize and analyze acupuncture points for diagnostic purposes. Yet, the electrical characterization of acupuncture points is associated with important technical issues that are often overlooked. Electrode polarizability, stratum corneum impedance, presence of sweat glands, choice of contact medium, electrode geometry, and other factors contribute to the final electrodermal reading and may cause doubts about the validity of available electrodiagnostic devices. The goal of this review is to help researchers and clinicians understand these factors affecting electrodermal readings, to make apparent the difficulties and challenges confronting electrodermal readings, and to increase understanding about how these possible associations can be interpreted and understood from the perspective of biology.

Cytokine, chemokine, and matrix metalloproteinase response after sulfur mustard injury to weanling pig skin.

Cutaneous exposure to sulfur mustard [bis(2-chloroethyl) sulfide; SM] produces a delayed inflammatory skin response and severe tissue injury. Pig skin has organ similarities to human skin that is characterized by the content and types of epidermal lipids, the density of hair follicles and presence of sweat glands, which together afford penetration of topically applied compounds, complex inflammatory responses, and subsequent wound healing. The goal of this study was to identify in vivo proinflammatory biomarkers of the SM porcine skin injury within 72 h after SM challenge, using the weanling pig model. Changes in gene expression of inflammatory mediators were examined at 3, 6, 24, 48, and 72 h, using subtraction library analyses and by quantitation of selected transcripts by reverse transcription-polymerase chain reaction (RT-PCR). Sequence analysis of subtraction libraries identified up-regulation of IL-8 at 24, 48, and 72 h. No other specific proinflammatory gene transcripts were isolated from the libraries. Specific transcript RT-PCR analysis showed increased production of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and matrix metalloproteinase-9 (MMP-9, gelatinase B) mRNA levels in response to SM exposure. Tumor necrosis factor-alpha (TNF-alpha) expression was only slightly increased and no change in the levels of expression was observed for monocyte chemoattractant protein-1 and MMP-2. This study identifies the main proinflammatory mediators involved in SM-induced skin injury in a weanling pig model. The results suggest transcriptional activity in the inflammatory response proteins IL-8, IL-6, IL-1beta, and MMP-9 and modest changes in TNF-alpha that together produce inflammation and contribute to the pathogenesis of SM dermatotoxicity. Therefore, drugs preventing SM-induced inflammation should be prime candidates for medical intervention to lessen collateral inflammation associated with tissue destruction.

Cutaneous histopathologic features in weanling pigs after exposure to three different doses of liquid sulfur mustard.

Sulfur mustard (2,2' dichlorodiethyl sulfide, HD) is a chemical warfare agent that is easily produced, and may be used against civilian populations as well as against military troops. However, good therapeutic and prophylactic measures await a better understanding of the pathophysiology of lesions produced by this agent. Because the skin remains is one of the principal routes for HD exposure and damage, the study of HD-induced skin lesions is of major interest. Blister formation is a characteristic of HD-induced skin lesions in humans. Attempts have been made to find an animal model that produces cutaneous microblisters after exposure to the naturally occurring liquid as well as vaporized HD. Weanling pigs were exposed to three different doses of liquid HD. Histopathologic findings showed microblister formation as well as variable apoptosis and/or necrosis of epidermal keratinocytes and vascular endothelium. Pig skin is morphologically similar to human skin. In the pig, the epidermal lipids, the density of hair follicles, the presence of sweat glands, the proliferation kinetics, and the antigenicity are all closer to human skin than are rodent models. All these features may be important in lesions induced by HD, and may mean that the pig is a superior model for studying the pathophysiology of HD-induced cutaneous lesions.

Production of Sweat Gland Cholinergic Differentiation Factor Depends on Innervation

Sympathetic neurons innervating sweat glands undergo a target-directed developmental switch in neurotransmitter properties. Using cultured sympathetic neurons as a bioassay for cholinergic differentiation factors, we and others found that extracts containing soluble proteins from developing and adult footpads caused the same changes in transmitter properties in sympathetic neurons in vitro that the target does in vivo. In the present studies, using footpads from Tabby mutant mice that lack sweat glands, we found that the presence of sweat glands is correlated with the presence of cholinergic differentiation activity in footpad extracts. We examined the conditions necessary for secretion of differentiation activity from primary cultures of sweat gland cells. Surprisingly, sweat gland cells cultured alone do not produce or secrete cholinergic differentiation activity. When grown in the presence of sympathetic neurons, however, gland cells induce cholinergic function, increase vasoactive intestinal peptide content, and reduce catecholamine production in the neurons. Medium conditioned by sweat gland/neuron cocultures has a similar effect on the transmitter properties of cultured sympathetic neurons, indicating that the target influence on phenotype is mediated by a secreted factor(s). The innervation-dependence of cholinergic differentiation factor production provides evidence that reciprocal interactions between neurons and sweat glands are necessary for acquisition of the mature transmitter phenotype.

Comparative Physiology of Metabolic Responses to Neurohypophysial Hormones in Vertebrates

The neurohypophysial (NHP) hormones in mammals are arginine vasopressin (AVP) (lysine vasopressin (LVP) in Suiformes) and oxytocin. Since these hormones have been implicated in the regulation of water balance and oxytocic functions in the body, metabolic responses to their action have to be considered in relation to problems associated with adaptive radiation and physiological evolution of vertebrates. Studies on species from different classes of vertebrates have shown that water deprivation, salt-loading and thermal stress could lead to the release of neurosecretory material (NSM) from the hypothalamo-neurohypophysial system (HNPS). Salt-loading has been shown to produce in rats significant decrease in both vasopressin and oxytocin in HNPS and also cause a fall in plasma free fatty acid (FFA) and a rise in plasma glucose. Injections of exogenous AVP and LVP decrease plasma FFA level in most of the mammals studied. AVP, LVP and oxytocin produce hyperglycemia in the mammals, birds and amphibians hitherto investigated. Arginine vasotocin (AVT) is shown to increase plasma FFA and glucose levels in the bird, fish and cyclostome. Possibly growth hormone (GH) is at least one of the extraneurohypophysial hormones through which the metabolic effects of AVT may be mediated. Thermal stress and dehydration in pigeons cause the release of NSM granules from the neurohypophysis and a rise in plasma levels of GH, cAMP and FFA with no significant change in glucose. Prostaglandin E, is found to increase plasma GH and FFA with a tendency toward hyperglycemia in the pigeon. Under heat stress, some reptiles, birds and mammals pant causing increased activity of the respiratory muscles. Increased activity can also cause rise in body temperature. Whether with exercise or increased body temperature the metabolic responses are indicated by increased mobilization and utilization of lipid which yields more energy and metabolic water than carbohydrate, thus sparing glucose for glycogen build-up in the muscles. In short-term muscular activity carbohydrate is the main fuel, whereas in long-term, fat becomes the preferred source of energy. In most mammals at least in in vivo experiments, AVP and LVP cause decrease in plasma FFA but increase in plasma glucose unlike AVT in birds as far as plasma FFA is concerned. This difference may be attributed to the presence of sweat glands in mammals which are thermoregulatory in function. The NHP hormones seem to have a regulatory role in bird migration. In certain birds there is found to be a build-up of NSM in HNPS towards migration and it is released before migration thereby possibly triggering a chain of regulatory and metabolic events. Melatonin which is known to release AVT has been shown to increase plasma levels of GH, FFA and glucose in the pigeon. The influence of environmental factors such as temperature and photoperiod in bird migration may be mediated through NHP and the pineal hormones.

Basic studies of the skin transplant for tympanoplasty.

Histological and in vivo examinations of skins were made in order to offer one of the grounds of tympanic skin grafting in the following 14 regions: the external auditory canal (cartilagineous portion), the retroauricular region, the upper arm (medial and lateral parts), the forearm (anterior and posterior parts), the thorax, the back, the abdomen (lateral and hypogastric parts), the inguinal region, the gluteal region, and the thigh (medial and lateral parts). Although considerably different in relation to individuals, both the data show some common characteristic trends of skin in different regious of the body surface irrespective of age. The present data were summarized as follows: L Thick skin pieces can be usually r emoved from the g luteal region and the abdomen. 2. The dis­ tribution of sebaceous glands is relativ el y scarce in the upper and lower extremities. Accordmgly, irrespective of the methods of transplantation, skin pieces removed from both the extremities are of more advantage in preventing them from infection and crust formation. 3. The distribution of sweat glands in skin pieces is almost uniform in the major reg ions ot the body surface. Skin pieces removed by the split thickness graft method are evenly available for tympanic grafting, and thos e from the back and gluteal r egions are of more advantage in preventing them from infection because of the deepest presence of sweat glands ther e. 4. The distribution and thickness of hairs have a rela tion with the success of tympanic skin grafting. Perforation of skin pieces, to be induced by the thin split thickness graft method, is prevented by using the thick split thickness graft method, due to regeneration from the remaining part of the hair roots in the deeper layer of skin pieces. The possibility of development of cholesteatoma f r om hair roots is, however, prevented by using the same skins in the full thickne ss graft method. 5. The ext ension and dis tribution of elastic fibers, especially of deep hori zontal thic k elastic fiber s , has a relation with th e success of tympa nic s kin grafting ­ skin pieces removed from the r etroauricular r egion, the back and the glut eal region are of advantage, because the distribution and extensi on of deep horizontal thick elastic fibers are found far deeper in those regions than anywhere else. 6. Considering from the abovementioned data, it is probable that skin transplants removed f rom the thigh , the back, the g luteal and r etroauricular reg ions are theoretically more avaiabl e a s tympanopl a stic material, although it is difficult to determin e t heir superiority or inferiori t y in detail a s tympanoplast ic material in the skins of th e whole body surfa ce examined.

Relationship between suint and the sweat glands

In the fleece of sheep with different types of skin, suint (cold water extract of the greasy fleece) was shown to be associated with the presence and size of the sweat glands. In the absence of sweat glands, suint was produced in substantially less than normal quantities, whereas the amount was much greater where the sweat glands were large.Similarly, the amount of potassium in suint, in skin, and in fluid from dermal cysts was much larger in the presence of sweat glands. The conclusion that suint is therefore largely produced by sweat glands was substantiated by the detection of high concentrations of potassium in sheep sweat.