Intranasal Versus Intravenous Dexamethasone to Treat Hospitalized COVID-19 Patients: A Randomized Multicenter Clinical Trial.

BACKGROUND: SARS-CoV2 induces flu-like symptoms that can rapidly progress to severe acute lung injury and even death. The virus also invades the central nervous system (CNS), causing neuroinflammation and death from central failure. Intravenous (IV) or oral dexamethasone (DXM) reduced 28 d mortality in patients who required supplemental oxygen compared to those who received conventional care alone. Through these routes, DMX fails to reach therapeutic levels in the CNS. In contrast, the intranasal (IN) route produces therapeutic levels of DXM in the CNS, even at low doses, with similar systemic bioavailability. AIMS: To compare IN vs. IV DXM treatment in hospitalized patients with COVID-19. METHODS: A controlled, multicenter, open-label trial. Patients with COVID-19 (69) were randomly assigned to receive IN-DXM (0.12 mg/kg for three days, followed by 0.6 mg/kg for up to seven days) or IV-DXM (6 mg/d for 10 d). The primary outcome was clinical improvement, as defined by the National Early Warning Score (NEWS) ordinal scale. The secondary outcome was death at 28 d between IV and IN patients. Effects of both treatments on biochemical and immunoinflammatory profiles were also recorded. RESULTS: Initially, no significant differences in clinical severity, biometrics, and immunoinflammatory parameters were found between both groups. The NEWS-2 score was reduced, in 23 IN-DXM treated patients, with no significant variations in the 46 IV-DXM treated ones. Ten IV-DXM-treated patients and only one IN-DXM patient died. CONCLUSIONS: IN-DMX reduced NEWS-2 and mortality more efficiently than IV-DXM, suggesting that IN is a more efficient route of DXM administration.

Low responsiveness of peripheral lymphocytes in extraparenchymal neurocysticercosis.

BACKGROUND: The morbidity and mortality of extraparenchymal neurocysticercosis (EP-NC) remain high and effectiveness of current medical treatment is suboptimal. Various factors have been implicated in the severity of EP-NC and in the poor response to treatment, but the possible role of host immune and endocrine systems has not yet been examined thoroughly. METHODOLOGY/PRINCIPAL FINDINGS: 42 participants with EP-NC before receiving standard treatment and 25 healthy controls were included in the study. Treatment response was assessed by comparing pre/post treatment parasite volumes from 3D MRI. Prior to treatment among participants with EP-NC, specific stimulation induced an increased specific proliferative response accompanied by a significant increase in IL-4, NK, NKT, Bregs and Tregs cells, whereas in healthy controls, specific stimulation induced a significant increase in IL-1ß, IL-5, CCL5, IL-6, TNF-α, NK and Bregs cells. Significant differences between participants with EP-NC and healthy controls in the specific inflammatory response were observed. Participants with EP-NC prior to treatment had significantly weaker responses of proinflammatory cytokines (IL-6, TNF-α) and NK cells, and stronger IL-4 response. Anthelmintic treatment did not promote significant peripheral immunological changes at any time, although inflammation was sustained in the cerebrospinal fluid. Serum estradiol concentration significantly decreased after anthelmintic treatment among males, and cortisol correlated negatively with IL-6 and positively with IFN-γ levels. No pre-treatment immunologic or endocrinologic parameters were significantly associated with response to treatment. CONCLUSION/SIGNIFICANCE: Prior to anthelmintic treatment, EP-NC was characterized by low lymphocyte reactivity accompanied by a regulatory response, which may be involved in the lack of peripheral immunological changes during and after treatment, although a central inflammatory response was present. This weak specific peripheral response could favor the chronicity of the infection and the poor response to treatment. Our findings highlight the need for new anti-inflammatory treatment focused on the central nervous system with less systemic immunosuppressive effects.

Physiological status of House Sparrows (Passer domesticus) along an ozone pollution gradient.

Mexico City is one of the most polluted cities in the world, and one in which air contamination is considered a public health threat. Numerous studies have related high concentrations of particulate matter and ozone to several respiratory and cardiovascular diseases and a higher human mortality risk. However, almost all of those studies have focused on human health outcomes, and the effects of anthropogenic air pollution on wildlife species is still poorly understood. In this study, we investigated the impacts of air pollution in the Mexico City Metropolitan Area (MCMA) on house sparrows (Passer domesticus). We assessed two physiological responses commonly used as biomarkers: stress response (the corticosterone concentration in feathers), and constitutive innate immune response (the concentration of both natural antibodies and lytic complement proteins), which are non-invasive techniques. We found a negative relationship between the ozone concentration and the natural antibodies response (p = 0.003). However, no relationship was found between the ozone concentration and the stress response or the complement system activity (p > 0.05). These results suggest that ozone concentrations in air pollution within MCMA may constrain the natural antibody response in the immune system of house sparrows. Our study shows, for the first time, the potential impact of ozone pollution on a wild species in the MCMA presenting the Nabs activity and the house sparrow as suitable indicators to assess the effect of air contamination on the songbirds.

Immunoendocrine abnormalities in the female reproductive system, and lung steroidogenesis during experimental pulmonary tuberculosis.

INTRODUCTION: Tuberculosis (TB) caused by Mycobacterium tuberculosis mainly affects the lungs, but can spread to other organs. TB chronically activates the immune and endocrine systems producing remarkable functional changes.So far, it is unknown whether pulmonary non-disseminated TB cause changes in the female reproductive system and lung endocrinology. OBJECTIVE: To investigate whether pulmonary TB produces immunoendocrine alterations of the female mice reproductive organs, and lung estradiol synthesis. METHODS: BALB/c mice were infected intratracheally with Mycobacterium tuberculosis (Mtb) strain H37Rv. Groups of six non-infected and infected animals were euthanized on different days. Bacillary loads were determined in the lungs, ovaries and uterus. Immunohistochemistry and morphometry studies were performed in histological sections. Serum estradiol wasassayed, and supernatantfrom cultured lung cells was analyzed by Thin Layer Chromatography (TLC). RESULTS: Mtb only grew in lung tissue. Histopathology revealed abnormal folliculogenesis and decreased corpora lutea. Altered ovarian expression of IL-6, IL-1ß was found. The infection increased serum estradiol. Estradiol synthesis by infected lung cells triplicate after 30 pi days.Aromatase immunostaining was found in the alveolar and bronchial epithelium, being stronger in the infected lungs, mainly in macrophages. CONCLUSION: Pulmonary TB affects the histophysiology of the female reproductive system in absence of its local infection, and disturbslung endocrinology.

Towards the development of an epitope-focused vaccine for SARS-CoV-2.

The rapid spread of COVID-19 on all continents and the mortality induced by SARS-CoV-2 virus, the cause of the pandemic coronavirus disease 2019 (COVID-19) has motivated an unprecedented effort for vaccine development. Inactivated viruses as well as vaccines focused on the partial or total sequence of the Spike protein using different novel platforms such us RNA, DNA, proteins, and non-replicating viral vectors have been developed. The high global need for vaccines, now and in the future, and the emergence of new variants of concern still requires development of accessible vaccines that can be adapted according to the most prevalent variants in the respective regions. Here, we describe the immunogenic properties of a group of theoretically predicted RBD peptides to be used as the first step towards the development of an effective, safe and low-cost epitope-focused vaccine. One of the tested peptides named P5, proved to be safe and immunogenic. Subcutaneous administration of the peptide, formulated with alumina, induced high levels of specific IgG antibodies in mice and hamsters, as well as an increase of IFN-γ expression by CD8+ T cells in C57 and BALB/c mice upon in vitro stimulation with P5. Neutralizing titers of anti-P5 antibodies, however, were disappointingly low, a deficiency that we will attempt to resolve by the inclusion of additional immunogenic epitopes to P5. The safety and immunogenicity data reported in this study support the use of this peptide as a starting point for the design of an epitope restricted vaccine.

Intranasal dexamethasone: a new clinical trial for the control of inflammation and neuroinflammation in COVID-19 patients.

BACKGROUND: By end December of 2021, COVID-19 has infected around 276 million individuals and caused over 5 million deaths worldwide. Infection results in dysregulated systemic inflammation, multi-organ dysfunction, and critical illness. Cells of the central nervous system are also affected, triggering an uncontrolled neuroinflammatory response. Low doses of glucocorticoids, administered orally or intravenously, reduce mortality among moderate and severe COVID-19 patients. However, low doses administered by these routes do not reach therapeutic levels in the CNS. In contrast, intranasally administered dexamethasone can result in therapeutic doses in the CNS even at low doses. METHODS: This is an approved open-label, multicenter, randomized controlled trial to compare the effectiveness of intranasal versus intravenous dexamethasone administered in low doses to moderate and severe COVID-19 adult patients. The protocol is conducted in five health institutions in Mexico City. A total of 120 patients will be randomized into two groups (intravenous vs. intranasal) at a 1:1 ratio. Both groups will be treated with the corresponding dexamethasone scheme for 10 days. The primary outcome of the study will be clinical improvement, defined as a statistically significant reduction in the NEWS-2 score of patients with intranasal versus intravenous dexamethasone administration. The secondary outcome will be the reduction in mortality during hospitalization. CONCLUSIONS: This protocol is currently in progress to improve the efficacy of the standard therapeutic dexamethasone regimen for moderate and severe COVID-19 patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04513184 . Registered November 12, 2020. Approved by La Comisión Federal para la Protección contra Riesgos Sanitarios (COFEPRIS) with identification number DI/20/407/04/36. People are currently being recruited.

Synergetic effects of immune challenge and stress depress cortisol, inflammatory response and antioxidant activity in fish-eating Myotis.

One of the most common tools in conservation physiology is the assessment of environmental stress via glucocorticoid measurement. However, little is known of its relationship with other stress-related biomarkers, and how the incidence of an immune challenge during long-term stress could affect an individual's overall stress response. We investigated here the relationship between basal and post-acute stress fecal cortisol metabolite (FC) with different antioxidant enzymes, oxidative damage and immune parameters in the fish-eating bat, Myotis vivesi We found that in both basal and post-stress conditions, FC was highly related with a number of antioxidant enzymes and immune parameters, but not to oxidative damage. We also assessed changes of FC through the seasons. Basal FC samples and stress reactivity after short-duration stress displayed similar levels during summer, autumn and early winter, but lower concentrations in late winter. Stress reactivity after long-duration stress was greater in summer and early winter. Finally, we tested the effect of a simultaneous exposure to a long, strong stress stimulus with an immune response stimulation by administrating adrenocorticotropic hormone (ACTH) and phytohemagglutinin (PHA) after 42 h. Results showed that when both stimuli were administrated, FC concentrations, inflammation and some antioxidant activity were lowered in comparison with the control and individual administration of the challenges. Our findings support the idea that animals maintain constant basal glucocorticoid levels when living in challenging environments, but response to acute stress differs seasonally and immune defense mechanisms and stress responses might be compromised when confronted with multiple challenges.

Evagination of metacestodes of the WFU strain of Taenia crassiceps and evaluation of the impact of immune suppression of hamsters during tapeworm development.

Taeniosis-cysticercosis caused by Taenia crassiceps (Zeder, 1800) is a useful experimental model for biomedical research, in substitution of Taenia solium Linnaeus, 1758, studied during decades to develop effective vaccination, novel anti-helminthic drugs and diagnostic tools. Cysticercosis in mouse (Mus musculus Linnaeus) is achieved by the larval subculturing of the Wake Forest University (WFU) strain of T. crassiceps. Golden hamster, Mesocricetus auratus (Waterhouse), has been shown to be the most suitable host for adult forms of parasite in experimental taeniosis. Metacestodes of T. crassiceps WFU multiply by budding without restrictions once inoculated into the mouse, while the number of tapeworms developed from these larvae in hamsters remains highly variable. Three objectives have been proposed to improve the infection of T. crassiceps WFU in hamsters: (1) to re-evaluate the need of immune suppression; (2) to investigate the advantage of infecting hamsters with metacestodes with in vitro protruded scolices; and (3) to compare a number of tapeworms developed from metacestodes subcultured in hamsters against those proliferated in mice. Our results demonstrated that when the evagination of murine metacestodes was high, the number of T. crassiceps WFU adults obtained from hamsters was also high. Immunosuppressive treatment remains relevant for this experimental rodent model. The hamster-to-hamster cysticercosis-taeniosis by T. crassiceps overcame the mouse-to-hamster model in the yield of adult specimens. In vitro scolex evagination and metacestode asexual proliferation in hamsters place this rodent model by T. crassiceps WFU as the most affordable experimental models with taeniids.

The effect of finasteride and dutasteride on the synthesis of neurosteroids by glioblastoma cells.

Glioblastoma (GBM) is the most aggressive local brain tumor and effective treatments are lacking. Many studies have proposed an important participation of steroid hormones in the development of gliomas. Evidence was provided by statistics analysis where the incidence in adult population is 50% higher in men than in women. Female patients have a better prognosis for survival compared to male patients with GBM. Also, the expression of receptors to estrogen, progesterone and androgens in glioma cell lines and tumor biopsies, and glucocorticoid receptors in GBM cell lines had been reported. Here we have investigated the effect of the pharmacological inhibition of 5-α reductases on the capacity of GBM derived cell lines C6 (rat) and U87 (human) to synthesize neurosteroids. As the knowledge of the pathways used to synthesize neurosteroids by GBM derived cells was incomplete, we have investigated the synthesis of these steroids by C6 and U87 cells using tritiated precursors and thin layer chromatography (TLC). Increasing concentrations of finasteride and dutasteride were added to U87 culture media that was collected after 24 and 48 h. The results of the study showed that C6 cells incubated with 3H-cholesterol yielded dihydroandrosterone, hydroxytestosterone, androstenediol, androstenedione and estriol, while U87 cells also synthesized progesterone, and androstanedione. Incubation with 3H-androstenedione or 3H-testosterone mainly yielded dihydrotestosterone, androsterone, dihydroandrosterone, hydroxytestosterone, and estradiol in both lines. To note, we showed here for the first time that U87 cells synthesize corticosteroids. Addition of finasteride or dutasteride to U87 cells reduced androgen and estrogen synthesis. Dutasteride also decreased the synthesis of dihydrocorticosterone and allotetrahydrodesoxycorticosterone while deoxycorticosterone was accumulated. In summary, both GBM cell lines synthesize numerous neurosteroids, including 5-α reductase products and 3α-HSD pathways that were inhibited by finasteride and dutasteride. These inhibitors may be considered as tools to control neurosteroid synthesis of potential relevance for GBM survival.

Immunoendocrine abnormalities in the male reproductive system during experimental pulmonary tuberculosis.

INTRODUCTION: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that mainly affects the lungs. Along the course of pulmonary TB there are remarkable changes in the production of cytokines that cause endocrine changes. So far, it is not known the physiological and histological changes in the male reproductive system during pulmonary TB. OBJECTIVE: To investigate whether pulmonary TB produces histological alterations of the BALB/c mice reproductive organs, as well as abnormalities in spermatogenesis, serum testosterone concentrations and expression of testicular cytokines. METHODS: BALB/c mice were infected intratracheally with high dose Mtb strain H37Rv. Groups of six non infected and infected animals were euthanized on days 1, 3, 7, 14, 21, 28, 60, 90 and 120 post-infection. Bacillary loads were determined by counting colony forming units (CFUs) in lungs, testes, prostate and seminal vesicles. Histological sections were obtained from the same organs. Spermatozoids number and quality were assessed by spermatobioscopy. Serum testosterone concentrations were determined by radioimmunoanalysis (RIA) in control and infected mice in each time of sacrifice. RESULTS: Mtb only grew in lung tissue. Serum androgens showed a trend to decrease in the infected mice compared to the healthy animals, the difference turn into statistically significance at post infection day 120. The weight of the testis was not modified throughout the study, and no histopathological changes were found. However, we detected a significant decrease in the weight of the seminal vesicles and prostate starting at 28 days post-infection. Atrophy of the seminal vesicles and prostate epithelia were significant, beginning after 60 days of infection. Spermatobioscopy revealed hypospermia in the later stages of the disease. We have observed in the testes a local significant disbalance on the cytokine profile (increase of IL-6 and decrease of IL-10 and TGF-b levels) together with a very significant reduction of the body weight during late pulmonary TB. CONCLUSION: Pulmonary TB affects the histophysiology of the male reproductive system due to hormonal changes, an imbalance of pro-inflammatory cytokine profile, and a wasting syndrome during late disease.

Proximal and Distal Predictors of the Spider Monkey's Stress Levels in Fragmented Landscapes.

The rapid loss, fragmentation and degradation of tropical forests threaten the survival of many animal species. However, the way in which these phenomena affect animal health has been poorly explored, thus limiting the design of appropriate conservation strategies. To address this, here we identified using linear mixed models the effect of proximal (diet, activity pattern, hunting and logging) and distal (sum of the basal areas of fruiting-tree species [SBAFS], landscape forest cover and degree of forest fragmentation) variables over fecal glucocorticoid metabolite (fGCM) levels-hormones associated with animal health and fitness-of six groups of spider monkeys (Ateles geoffroyi) inhabiting six landscapes with different spatial structures in Mexico. Proximal variables showed a stronger predictive power over fGCMs than distal. In this sense, increases in travel time, the occurrence of hunting, and reductions in rest time and fruit consumption resulted in higher fGCM levels. Regarding distal variables, increases in SBAFS were negatively related to fGCM levels, thus suggesting that food scarcity increases stress hormone levels. Nevertheless, contrary to theoretical expectations, spider monkeys living in smaller tracts of forest spent less time travelling, but the same time feeding on fruit as those in more forested areas. The lower net energy return associated with this combination of factors would explain why, contrary to theoretical expectations, increased forest cover was associated with increased levels of fGCMs in these groups. Our study shows that, at least in the short term, spider monkeys in fragmented landscapes do not always present higher levels of stress hormones compared to those inhabiting continuous forest, and the importance of preserving fruit sources and controlling hunting for reducing the levels of stress hormones in free ranging spider monkeys.

Parasites and steroid hormones: corticosteroid and sex steroid synthesis, their role in the parasite physiology and development.

In many cases parasites display highly complex life cycles that include the penetration and permanence of the larva or adults within host organs, but even in those that only have one host, reciprocal, intricate interactions occur. Evidence indicates that steroid hormones have an influence on the development and course of parasitic infections. The host gender's susceptibility to infection, and the related differences in the immune response are good examples of the host-parasite interplay. However, the capacity of these organisms to synthesize their own steroidogenic hormones still has more questions than answers. It is now well-known that many parasites synthesize ecdysteroids, but limited information is available on sex steroid and corticosteroid synthesis. This review intends to summarize some of the existing information in the field. In most, but not all parasitosis the host's hormonal environment determines the susceptibility, the course, and severity of parasite infections. In most cases the infection disturbs the host environment, and activates immune responses that end up affecting the endocrine system. Furthermore, sex steroids and corticosteroids may also directly modify the parasite reproduction and molting. Available information indicates that parasites synthesize some steroid hormones, such as ecdysteroids and sex steroids, and the presence and activity of related enzymes have been demonstrated. More recently, the synthesis of corticosteroid-like compounds has been shown in Taenia solium cysticerci and tapeworms, and in Taenia crassiceps WFU cysticerci. In-depth knowledge of the parasite's endocrine properties will contribute to understand their reproduction and reciprocal interactions with the host, and may also help designing tools to combat the infection in some clinical situations.

Human papillomavirus type 16 E7 oncoprotein upregulates the retinoic acid receptor-beta expression in cervical cancer cell lines and K14E7 transgenic mice.

Persistent infection with high-risk human papillomaviruses is the main etiological factor in cervical cancer (CC). The human papillomavirus type 16 (HPV16) E7 oncoprotein alters several cellular processes, regulating the expression of many genes in order to avoid cell cycle control. Retinoic acid receptor beta (RARB) blocks cell growth, inducing differentiation and apoptosis. This tumor suppressor gene is gradually silenced in late passages of foreskin keratinocytes immortalized with HPV16 and in various tumors, including CC, mainly by epigenetic modifications. We investigated the effect of E7 oncoprotein on RARB gene expression. We found that HPV16 E7 increases RARB mRNA and RAR-beta protein expression both in vitro and in the cervix of young K14E7 transgenic mice. In E7-expressing cells, RARB overexpression is further increased in the presence of the tumor suppressor p53 (TP53) R273C mutant. This effect does not change when either C33-A or E7-expressing C33-A cell line is treated with Trichostatin A, suggesting that E7 enhances RARB expression independently of histone deacetylases inhibition. These findings indicate that RARB overexpression is part of the early molecular events induced by the E7 oncoprotein.

Mycobacterium smegmatis synthesizes in vitro androgens and estrogens from different steroid precursors.

Fast-growing mycobacteria such as Mycobacterium sp. and Mycobacterium smegmatis degrade natural sterols. They are a model to study tuberculosis. Interestingly, M. smegmatis has been found in river effluents derived from paper production, and therefore, it would be important to gain further insight into its capacity to synthesize steroids that are potential endocrine disruptors affecting the development and reproduction of fishes. To our knowledge, the capacity of M. smegmatis to synthesize estrogens and even testosterone has not been previously reported. Therefore, the objective of this study was to investigate the capacity of M. smegmatis to synthesize in vitro testosterone and estrogens from tritiated precursors and to investigate the metabolic pathways involved. Results obtained by thin-layer chromatography showed that (3)H-progesterone was transformed to 17OH-progesterone, androstenedione, testosterone, estrone, and estradiol after 6, 12, or 24 h of incubation. (3)H-androstenedione was transformed into testosterone and estrogens, mainly estrone, and (3)H-testosterone was transformed to estrone and androstenedione. Incubation with (3)H-dehydroepiandrosterone rendered androstenediol, testosterone, and estrogens. This ability to transform less potent sex steroids like androstenedione and estrone into other more active steroids like testosterone and estradiol or vice versa suggests that M. smegmatis can influence the amount of self-synthesized strong androgens and estrogens and can transform those found in the environment.

Assessment of adrenocortical and gonadal hormones in male spider monkeys (Ateles geoffroyi) following capture, restraint and anesthesia.

The spider monkey (SM) (Ateles geoffroyi) a New World primate species native to Mexican forests, has become endangered in the wild due to environmental perturbations. Little is known about adrenal function and its relationship to reproduction in this species. Our objectives were to assess serum glucocorticoid (GC), mineralocorticoid (MC) and testosterone concentrations in captive SM and evaluate adrenal and testicular responses to potentially stressful animal handling procedures. Seven adult males, housed in a single mixed gender group in an off-exhibit enclosure at the University Park were captured for anesthesia every 2 months over a 1-year period. Blood samples were collected from each male at three time points: (1) ∼5-10 min after ketamine injection in the outdoor enclosure; (2) ∼2 hr later following animal transport to the laboratory and immediately after tiletamine-zolazepam injection; and (3) ∼20-30 min following the second anesthetic injection. Serum samples were frozen and later analyzed for cortisol, corticosterone, aldosterone and testosterone via radioimmunoassay. Cortisol was the primary GC detected in SM serum with much higher mean concentrations than for corticosterone. Capture, restraint and anesthesia resulted in significant increases in both cortisol and corticosterone concentrations. Whereas aldosterone concentrations were unchanged by animal handling procedures, testosterone concentrations significantly declined under anesthesia over time. In summary, these results provide data for the main adrenocortical hormones in male SM and characterize their acute adrenal responses to potentially stressful handling and anesthesia procedures. Our findings also suggest an interaction between acute increases in corticosteroids and decreased concentrations of serum testosterone.

Impact of Taenia solium neurocysticercosis upon endocrine status and its relation with immuno-inflammatory parameters.

Neurocysticercosis (NC) is a parasitic disease caused by the infiltration of the larval stage of Taenia solium in the central nervous system. Clinical presentations are heterogeneous and particularly depend, on the age and gender of the host. We designed a clinical study to evaluate the hormonal changes associated with neurocysticercosis and the relationships between disease heterogeneity, endocrine and immunological status. A total of 50 patients and 22 healthy subjects were included. A precise clinical and radiological description of disease for each patient was recorded. A broad hormonal profile was assessed for each participant and, in a sub-group of patients, immunological features were also evaluated. Compared with controls, all patients had lower dehydroepiandrosterone (DHEA) concentration; male patients also had lower concentrations of 17ß-estradiol and higher concentrations of luteinising hormone (LH). In the clinically severe patients, lower concentrations of progesterone and androstenedione were found in women. Higher concentrations of follicle stimulating hormone (FSH) and lower concentrations of testosterone were found in men when compared with the less clinically severe patients. Significant correlations were found between estradiol and IL-10 in male patients, and between dehydroepiandrosterone (DHEA) and IL-1ß, and androstenedione and IL-17 in female patients. To our knowledge the present study constitutes the first demonstration that the presence of T. solium larvae in the central nervous system can modify the host environment by the induction of endocrine and immunological changes. These results provide a stimulating background to analyse the repercussions of these changes on the course of the disease and on patient reproductive health.

Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle.

Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle.

Stress in wildlife species: noninvasive monitoring of glucocorticoids.

Depression and stress are related pathologies extensively studied in humans. However, this relationship is not well known in animals kept in zoos and even less known in wild animals. In zoo animals, acute and chronic stress caused by difficulties in coping with stressors such as public presence and noise, among others, can induce the appearance of repetitive pathological behaviors such as stereotypies, many times associated with organic pathologies that deeply affect their health and welfare. In the wild, factors such as deforestation, habitat fragmentation, lack of food and water, and human disturbances are potential causes of acute and chronic stress for the resident fauna. Glucocorticoids (GC) have been extensively used as stress indicators in many species including humans. Since chase and handling of wild animals immediately raise their GC serum levels, noninvasive methods have been developed to assess stress without interference caused by sample collection. The hormones and their metabolites can be measured in various body fluids and excreta and detect basal feedback free hormone concentrations as well as the response to ACTH and handling. In order to study the influence of disturbing factors we have measured GC as stress indicators by noninvasive techniques in dolphins and felids (ocelots, jaguarundis and margays) and cortisol and testosterone in spider monkeys.

The key steroidogenic enzyme 3beta-hydroxysteroid dehydrogenase in Taenia solium and Taenia crassiceps (WFU).

Larval and adult stages of Taenia solium and Taenia crassiceps WFU strain were analyzed by histochemical and biochemical methods to determine the existence of steroid pathways. The presence of the key enzyme 3beta-hydroxisteroid-dehydrogenase (3beta-HSD) was examined in frozen sections of cysticerci obtained from mice and segments of tapeworms obtained from the intestine of hamsters. 3beta-HSD activity was detected by nitroblue-tetrazolium products after incubation with dehydroepiandrosterone, androstendiol, or pregnenolone. Tapeworm tissues exhibited 3beta-HSD activity in the subtegumentary areas of the neck and immature proglottids following incubation with androstendiol, as well as surrounding the testes in mature proglottids. T. solium cysticerci exhibited 3beta-HSD activity in the subtegumentary tissues. The synthesis of steroid hormones involving the activity of 3beta-HSD was studied in cysticerci or tapeworms incubated in the presence of tritiated steroid precursors. The culture media were analyzed by thin layer chromatography and showed synthesis of androstendiol, testosterone, and 17beta-estradiol by cysticerci, androstendiol, and 17beta-estradiol by tapeworms. The results strongly suggest the activity of 3beta-HSD in taeniid parasites that have at least a part of the enzymatic chain required for androgen and estrogen synthesis and that the enzymes are present in the larval stage and from the early strobilar stages to the mature proglottids.