Impact of sex on hyperalgesia induced by sleep loss

This study evaluated the impact of sex on the short term consequences of different periods of sleep deprivation and the effect of the respective sleep recovery periods on nociceptive responses. Male and female C57BL/6J mice were assigned to the following groups: paradoxical sleep deprived (PSD) for 72 h, sleep restricted (SR) for 15 days, exposed to respective recovery periods for 24 h, or untreated home-cage controls (CTRL). Mice were submitted to a noxious thermal stimulus to evaluate their nociceptive response after PSD, SR, or recovery periods. Blood was collected for hormonal analysis. the nociceptive response was significantly lower in PSD and SR mice compared to CTRL animals, regardless of the sex. However, SR females had a lower paw withdrawal threshold than males. Sleep recovery was able to restore normal nociceptive sensitivity after PSD in both sexes. the hyperalgesia induced by SR was not reversed by sleep rebound. in females, low concentrations of estradiol were found after SR, and these concentrations continued to decrease after 24 hours of sleep recovery. the PSD male mice exhibited higher concentrations of corticosterone than the CTRL and SR male mice. Corticosterone levels were not affected by SR. Our study revealed that PSD and SR induce hyperalgesia in mice. the SR groups showed marked changes in the nociceptive response, and the females were more sensitive to these alterations. This finding indicates that, although different periods of sleep deprivation change the nociceptive sensitivity in male and female mice, sex could influence hyperalgesia induced by chronic sleep loss. (C) 2010 Elsevier Inc. All rights reserved.Associacao Fundo de Incentivo a Psicofarmacologia (AFIP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Psicobiol, BR-04024002 São Paulo, BrazilUniv Fed Goias, Dept Ciencias Fisiol, Goiania, Go, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04024002 São Paulo, BrazilFAPESP: 98/14303-3FAPESP: 10/50130-0Web of Scienc

Comparação entre dois protocolos experimentais para promover osteoporose no osso maxilar e na tíbia proximal de ratas

The effects of two experimental protocols (ovariectomy associated or not with a low calcium diet) used to promote osteoporosis in the rat maxilla and proximal tibia were compared 5 and 11 weeks after surgery. Female Wistar rats were ovariectomized or sham-operated. Half of the ovariectomized rats were fed a low Ca++ diet (ovx*) and the remaining ovariectomized (ovx) and sham animals received a standard chow. At sacrifice, the proximal metaphysis was excised from the tibia and the molars were extracted from the hemi-maxilla. Dry (60°C overnight) and ash (700°C/14 h) weights were measured and the ashes were used for Ca++ measurement by means of a colorimetric method. After 5 weeks, ovx caused no alteration while ovx* decreased proximal metaphysis (17%) and maxilla (35%) bone mass. After 11 weeks, ovx caused a 14% bone mass reduction in the proximal metaphysis but not in the maxilla, while ovx* caused a comparable bone mass reduction (30%) in both bone segments. Calcium concentration was not altered in any experimental condition. The results show that estrogen deficiency is insufficient to cause maxillary osteoporosis in rats over an 11-week period and a long-term ovariectomy is needed to exert deleterious effect on proximal metaphysis bone mass. When a low Ca++ diet is associated with estrogen deficiency, however, a relatively precocious harmful effect is observed, twice as pronounced in the maxilla than in the proximal metaphysis. On a long-term basis, ovariectomy associated with a low Ca++ diet seems to be equally injurious to both proximal metaphysis and maxilla.Comparou-se o efeito de dois protocolos experimentais (ovariectomia associada ou não à dieta pobre em Ca++) utilizados para promover osteoporose em maxila e metáfise proximal de ratas, nos períodos de 5 e 11 semanas pós-cirurgia. Ratas Wistar foram ovariectomizadas ou submetidas à cirurgia simulada. Metade das ratas ovariectomizadas recebeu dieta pobre em Ca++ (ovx*) e as demais (ovx), assim como as que sofreram falsa cirurgia, receberam dieta comercial. Foram coletados o osso maxilar (após extração dos molares) e a metáfise proximal da tíbia para medidas do peso seco (60ºC/12 h) e do da cinza óssea (700ºC/14 h), utilizada para dosagem de Ca++ (método colorimétrico). Cinco semanas após a cirurgia, não se observaram alterações nos parâmetros investigados no grupo ovx, enquanto no grupo ovx* houve redução da massa óssea da metáfise proximal (17%) e da maxila (35%). Após 11 semanas, o grupo ovx apresentou 14% de redução da massa óssea da metáfise proximal, mas não da maxila, enquanto no grupo ovx* observou-se diminuição de 30% em ambos os segmentos ósseos. A concentração de Ca++ na cinza não se alterou em nenhuma condição experimental. Os resultados mostram que apenas a deficiência de estrógeno não é suficiente para provocar osteoporose maxilar em ratas num período de até 11 semanas, mas que nesse período já se observa seu efeito deletério na massa da metáfise proximal. Quando se associa a ovariectomia à dieta pobre em Ca++, observa-se diminuição da massa óssea após 5 semanas, 2 vezes maior na maxila do que na metáfise proximal da tíbia

Melanocytoma-acanthoma in a Dog

Background: Melanocytic neoplasms are skin tumors that often occur in dogs.  However, melanocytoma-acanthoma, also called melanoacanthoma, is a benign melanocytic neoplasm rarely reported in this species, which has been described only three times in the veterinary literature. Briefly, this tumor is characterized by a single, painless, darkly pigmented and firm cutaneous papule or nodule. Histologically, it is composed of mixed populations of well-differentiated melanocytes and keratinocytes, unlike traditional melanocytic tumors (melanoma and melanocytoma). These cells are arranged in lobules surrounded by collagenous stroma. Melanocytes are large epithelioid cells containing varying amounts of melanin. Keratinocytes form anastomosing trabeculae with peripheral palisading, and small cysts containing amorphous or laminated keratin. The definitive diagnosis of melanocytoma-acanthoma is based on histopathological findings. This report describes a case of melanocytoma-acanthoma in a dog in Brazil.Case: A 9-year-old female miniature Schnauzer dog was examined at the Veterinary Hospital of the Federal University of Santa Maria, where a single, firm, pigmented papule was found in the auricle. The lesion had started 15 days earlier. Hematological tests and serum biochemistry profile were normal. An excisional biopsy of the papule was surgically removed and subjected to histopathological examination. The tissue was fixed in 10% neutral buffered formalin, processed routinely and embedded in paraffin wax. Sections were stained with hematoxylin and eosin (HE). A histopathological examination revealed a nonencapsulated, well-defined, extensive, densely cellular proliferation located in dermis. This proliferation was composed of lobules and nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes, surrounded by thin bundles of fibrous stroma. A diagnosis of melanocytoma-acanthoma was established based on these histological features.Discussion: The first description of melanocytoma-acanthoma in humans was as melano-epithelioma, classified into subtypes I and II. Both subtypes are benign neoplasms composed of well-differentiated melanocytes and keratinocytes, which are distinguished from one another based on the amount and distribution of melanocytes. Type I melano-epithelioma is characterized by proliferative lobules of melanocytes and keratinocytes, including melanocytes scattered diffusely among keratinocytes. Type II melano-epithelioma involves only the proliferation of keratinocytes, while melanocytes are limited to the basal layer of keratinocyte lobules. To clarify this condition, some authors use the term “melanoacanthoma” to indicate the above-described type I melano-epithelioma, and seborrheic keratosis to indicate type II melano-epithelioma. However, other authors use the term melanoacanthoma to denote the two conditions (types I and II melano-epithelioma). On the other hand, veterinary medicine does not recognize subtypes, instead using the term melanocytoma-acanthoma, and more recently, melanoacanthoma, to denote this cutaneous neoplasm. Melanocytoma-acanthoma in dogs was first reported in Spain, and involved a 2-year-old German shepherd dog. Later, two other cases were described in adult mixed-breed dogs, one in South Korea and the other in Libya. This is the first report of melanocytoma-acanthoma in a dog in Brazil. The gross and histopathological appearance of this case matches that described in the previous cases (a single, well-defined, pigmented cutaneous papule or nodule). Histologically, the differential diagnosis for melanocytoma-acanthoma includes melanoma, melanocytoma, trichoepithelioma, and sebaceous epithelioma.

Melanocytoma-acanthoma in a Dog

Background: Melanocytic neoplasms are skin tumors that often occur in dogs.  However, melanocytoma-acanthoma, also called melanoacanthoma, is a benign melanocytic neoplasm rarely reported in this species, which has been described only three times in the veterinary literature. Briefly, this tumor is characterized by a single, painless, darkly pigmented and firm cutaneous papule or nodule. Histologically, it is composed of mixed populations of well-differentiated melanocytes and keratinocytes, unlike traditional melanocytic tumors (melanoma and melanocytoma). These cells are arranged in lobules surrounded by collagenous stroma. Melanocytes are large epithelioid cells containing varying amounts of melanin. Keratinocytes form anastomosing trabeculae with peripheral palisading, and small cysts containing amorphous or laminated keratin. The definitive diagnosis of melanocytoma-acanthoma is based on histopathological findings. This report describes a case of melanocytoma-acanthoma in a dog in Brazil.Case: A 9-year-old female miniature Schnauzer dog was examined at the Veterinary Hospital of the Federal University of Santa Maria, where a single, firm, pigmented papule was found in the auricle. The lesion had started 15 days earlier. Hematological tests and serum biochemistry profile were normal. An excisional biopsy of the papule was surgically removed and subjected to histopathological examination. The tissue was fixed in 10% neutral buffered formalin, processed routinely and embedded in paraffin wax. Sections were stained with hematoxylin and eosin (HE). A histopathological examination revealed a nonencapsulated, well-defined, extensive, densely cellular proliferation located in dermis. This proliferation was composed of lobules and nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes, surrounded by thin bundles of fibrous stroma. A diagnosis of melanocytoma-acanthoma was established based on these histological features.Discussion: The first description of melanocytoma-acanthoma in humans was as melano-epithelioma, classified into subtypes I and II. Both subtypes are benign neoplasms composed of well-differentiated melanocytes and keratinocytes, which are distinguished from one another based on the amount and distribution of melanocytes. Type I melano-epithelioma is characterized by proliferative lobules of melanocytes and keratinocytes, including melanocytes scattered diffusely among keratinocytes. Type II melano-epithelioma involves only the proliferation of keratinocytes, while melanocytes are limited to the basal layer of keratinocyte lobules. To clarify this condition, some authors use the term “melanoacanthoma” to indicate the above-described type I melano-epithelioma, and seborrheic keratosis to indicate type II melano-epithelioma. However, other authors use the term melanoacanthoma to denote the two conditions (types I and II melano-epithelioma). On the other hand, veterinary medicine does not recognize subtypes, instead using the term melanocytoma-acanthoma, and more recently, melanoacanthoma, to denote this cutaneous neoplasm. Melanocytoma-acanthoma in dogs was first reported in Spain, and involved a 2-year-old German shepherd dog. Later, two other cases were described in adult mixed-breed dogs, one in South Korea and the other in Libya. This is the first report of melanocytoma-acanthoma in a dog in Brazil. The gross and histopathological appearance of this case matches that described in the previous cases (a single, well-defined, pigmented cutaneous papule or nodule). Histologically, the differential diagnosis for melanocytoma-acanthoma includes melanoma, melanocytoma, trichoepithelioma, and sebaceous epithelioma.

Impairment of male reproductive function after sleep deprivation

Objective: To evaluate the influence of sleep loss on sexual behavior, hormone levels, sperm parameters, and testis-specific gene expression in male rats.Design: Experimental research.Setting: Animal laboratory.Animal(s): Male adult Wistar-Hannover rats.Intervention(s): Sexually experienced rats were subjected to paradoxic sleep deprivation (PSD) for 96 hours or sleep restriction (SR) for 21 days or kept in their home cage as control (CTRL).Main Outcome Measure(s): Sexual behavior, hormone levels, sperm parameters and expression of stress and nitric oxide-related genes were evaluated.Result(s): PSD significantly decreased sexual behavior compared with the CTRL group, whereas SR had no effect. the PSD group had significantly lower testosterone levels than the CTRL group. Both PSD and SR groups had lower sperm viabilities than the CTRL group. the decrease in the number of live sperm compared with the CTRL group was larger in the PSD group than in the SR group. Regarding testicular gene expression, both PSD and SR led to an increase of iNOS and hydroxysteroid 11 beta-dehydrogenase 1 expressions compared with the CTRL group. These changes were more pronounced in the PSD group. A significant increase in endothelial nitric oxide synthase expression was observed in the PSD groups compared with the CTRL group. No changes were observed in dimethylarginine dimethylaminohydrolase 1 and casein kinase 2 beta-polypeptide expressions.Conclusion(s): Sleep loss can promote marked changes in the male reproductive system of rats, particularly affecting spermatic function in part by interfering in the testicular nitric oxide pathway. (C) 2015 by American Society for Reproductive Medicine.Associacao Fundo de Apoio a Pesquisa (AFIP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)MEC-SeSU (PET) fellowshipUniversidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilUniv Fed Goias, Dept Pharmacol, Goias, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilFAPESP: 2014/15259-2FAPESP: 11/12325-6FAPESP: 12/05396-7Web of Scienc

The association of testosterone, sleep, and sexual function in men and women

Testosterone has been the focus of several investigations and review studies in males, but few have addressed its effects on sleep and sexual function, despite evidence of its androgenic effects on circadian activity in both sexes. Studies have been conducted to understand how sleeping increases (and how waking decreases) testosterone levels and how this rhythm can be related to sexual function. This review addresses the inter-relationships among testosterone, sexual function and sleep, including sleep-disordered breathing in both sexes, specifically its effects related to sleep deprivation. in addition, hormonal changes in testosterone that occur in the gonadal and adrenal axis with obstructive sleep apnea and other conditions of chronic sleep deprivation, and which consequently affect sexual life, have also been explored. Nevertheless, hormone-associated sleep disruptions occur across a lifetime, particularly in women. the association between endogenous testosterone and sex, sleep and sleep disturbances is discussed, including the results of clinical trials as well as animal model studies. Evidence of possible pathophysiological mechanisms underlying this relationship is also described. Unraveling the associations of sex steroid hormone concentrations with sleep and sexual function may have clinical implications, as sleep loss reduces testosterone levels in males, and low sex steroid hormone concentrations have been associated with sexual dysfunction. (C) 2011 Elsevier B.V. All rights reserved.Associacao Fundo de Incentivo a Pesquisa (AFIP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ginecol, BR-04024002 São Paulo, BrazilUniv Fed Goias, Dept Ciencias Fisiol, Goiania, Go, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, BR-04024002 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ginecol, BR-04024002 São Paulo, BrazilFAPESP: 98/14.303-3FAPESP: 09/14206-4FAPESP: 09/01030-5Web of Scienc