The Campo de Dalias GNSS Network Unveils the Interaction between Roll-Back and Indentation Tectonics in the Gibraltar Arc.

The Gibraltar Arc includes the Betic and Rif Cordilleras surrounding the Alboran Sea; it is formed at the northwest-southeast Eurasia-Nubia convergent plate boundary in the westernmost Mediterranean. Since 2006, the Campo de Dalias GNSS network has monitored active tectonic deformation of the most seismically active area on the north coast of the Alboran Sea. Our results show that the residual deformation rates with respect to Eurasia range from 1.7 to 3.0 mm/year; roughly homogenous west-southwestward displacements of the northern sites occur, while the southern sites evidence irregular displacements towards the west and northwest. This deformation pattern supports simultaneous east-northeast-west-southwest extension, accommodated by normal and oblique faults, and north-northwest-south-southeast shortening that develops east-northeast-west-southwest folds. Moreover, the GNSS results point to dextral creep of the main northwest-southeast Balanegra Fault. These GNNS results thus reveal, for the first time, present-day interaction of the roll-back tectonics of the Rif-Gibraltar-Betic slab in the western part of the Gibraltar Arc with the indentation tectonics affecting the eastern and southern areas, providing new insights for improving tectonic models of arcuate orogens.

Embryo production after superovulation of bovine donors with a reduced number of FSH applications and an increased eCG dose.

This study evaluated embryo production after superovulation (SO) with a reduced number of FSH applications and increased eCG dose in 26 Bos taurus × Bos indicus donors. On Day 0, donors received an intravaginal device (CIDR) with 1.9 g of progesterone plus 2.5 mg of estradiol benzoate and 50 mg of progesterone via IM. On Day 4, donors were randomly allotted to one of three SO treatments: 1) 455 IU of Folltropin +400 IU of eCG (n = 9), 2) 350 IU of Folltropin +600 IU of eCG (n = 9), and 3) 500 IU of Pluset + 600 IU of eCG (n = 8). In treatment 455 IU of Folltropin +400 IU of eCG, donors received eight IM Folltropin injections in decreasing dose 12 h apart from Day 4 to Day 7. On Day 6, at the same time as the Folltropin, donors received via IM 25 mg of dinoprost tromethamine (PGF2a). On Day 7, the CIDR was removed, and together with the Folltropin, donors received 200 IU of eCG via IM. In treatment 350 IU of Folltropin +600 IU of eCG, donors received four IM Folltropin injections in decreasing dose 12 h apart on Days 4 and 5. On Day 6, donors received via IM 600 IU of eCG in the morning and two doses of 25 mg of PGF2a 12 h apart. On Day 7, the CIDR was removed. Donors from treatment 500 IU of Pluset +600 IU of eCG received four IM Pluset injections in decreasing dose 12 h apart on Days 4 and 5. On Day 6, donors received via IM 600 IU of eCG in the morning and two doses of 25 mg of PGF2a 12 h apart. On Day 7, the CIDR was removed. In the morning of Day 8, donors from the three treatments received 0.25 mg of GnRH via IM. Artificial insemination was performed on Day 8 (pm) and Day 9 (am). Embryos were collected on Day 15. Variables evaluated were number of CL before embryo collection, number of structures recovered, transferable embryos, degenerate embryos and unfertilized oocytes, recovery rate, and viability rate. There was no difference in any variable among treatments (P > 0.05). In conclusion, replacement of four Folltropin or Pluset injections from a conventional eight FSH-injection SO protocol, by a single injection of 600 IU of eCG, is a good alternative to reduce donor handling without decreasing yield of transferable embryos.

Embryo production in middle-aged and mature Bos taurus × Bos indicus cows induced to multiple ovulation in a tropical environment.

The objective of the study was to evaluate embryo production in middle-aged and mature Bos taurus × Bos indicus cows induced to multiple ovulation (MO) in a tropical environment. Twenty-eight cows were assigned into two groups: (1) middle-aged cows = 4-6 years old (n = 13), and (2) mature cows = 8-12 years old (n = 15). All donors received the same MO protocol with follicle-stimulating hormone in decreasing dose during 4 days and two artificial insemination services. Total numbers of corpora lutea at embryo collection, structures collected, and viable embryos obtained, as well as recovery rate, were higher in middle-aged cows compared with mature cows (P < 0.05). A total number of degenerate embryos and unfertilized oocytes, as well as viability rate, were similar in both groups (P > 0.05). In conclusion, the mature cows responded to the MO treatment, but the average of viable embryos recovered per donor was lower than in middle-aged cows. Therefore, the inclusion of cows ≥ 8 years old as donors in MO programs in tropical environments should be avoided.

A computerized version of the Patient Health Questionnaire-4 as an ultra-brief screening tool to detect emotional disorders in primary care.

BACKGROUND: The Patient Health Questionnaire-4 (PHQ-4) is an ultra-brief self-report consisting of a 2-item depression scale (PHQ-2) and a 2-item anxiety scale (GAD-2). The aim of the present study is to determine the psychometric properties of a computerized version of the PHQ-4 used to detect emotional disorders (anxiety and depression) in the primary care setting. METHOD: A total of 1052 patients with suspected anxiety, depression, or somatic symptoms were recruited from 28 primary care centres participating in the PsicAP trial and completed the full version of the computerized PHQ. In addition, 178 of these patients also underwent in clinical interviews as a gold standard. RESULTS: Confirmatory factor analyses showed very good fit indices for a two-factor solution. This model was structurally invariant among the various age and gender groups and internal consistency was acceptable (PHQ-4; α = .83, PHQ-2; α = .86, and GAD-2; α = .76). The best cut-off points to obtain high sensitivity values was 3, on both the PHQ-2 (major depressive disorder) and the GAD-2 (generalized anxiety disorder). The criterion validity (sensitivity and specificity) for the PHQ-2 were .90 and .61 and for the GAD-2, .88 and 0.61. LIMITATIONS: The study was not designed as a prevalence study. Therefore, does not contain information on patients whose general practitioners do not consider them to suffer emotional disorders. CONCLUSION: This is the first study to provide evidence for the reliability and validity of a computerized version of the PHQ-4. This computerized tool can be used to detect depression and anxiety in a primary care setting.

Volunteer Functions Inventory: A systematic review / El inventario de funciones del voluntariado: una revisión sistemática

The objective of this research study was to conduct a systematic review of the research on volunteers using Clary et al.’s VFI (1998). A total of 48 research studies including 67 independent samples met eligibility criteria. The total sample of the studies analyzed ranged from 20375 to 21988 participants, depending on the motivation analyzed. The results show that the Values factor obtained the highest mean score, both overall and in each type of volunteering, whereas the lowest scores were for the Career and Enhancement factors. Studies conducted with samples with a mean age under 40 years obtain higher scores on Career and Understanding scales when compared to studies in older samples. The group of studies with less than 50% women yield higher mean scores on the Social scale than studies with more than 50% women in the sample. All the scales show reliability coefficients between .78 and .84. Only eight of the articles provide data on the reliability of the scale with a mean value of .90. Of the 26 studies that performed factor analysis, 18 confirmed the original structure of six factors (AU)

Antecedentes: las motivaciones son variables clave para comprender el comportamiento de los voluntarios. El objetivo de esta investigación es realizar una revisión sistemática de las investigaciones sobre voluntariado que hayan usado el VFI de Clary et al. (1998). Método: 48 investigaciones, con 67 muestras independientes, cumplían los criterios de elegibilidad. El total de la muestra de los estudios oscila entre 20.375 y 21.988 participantes, según el motivo analizado. Resultados: el factor Valores obtiene la mayor puntuación media en general y en cada tipo de voluntariado, las puntuaciones más bajas corresponden a los factores Mejora del Curriculum y Defensa del Yo. Los estudios realizados con muestras menores de 40 años de edad media obtienen puntuaciones mayores en las escalas de Mejora del Curriculum y Conocimiento. Los estudios con menos del 50 % de mujeres arrojan medias más altas en la escala Social que los estudios con más del 50 % de mujeres en la muestra. Todas las escalas muestran coeficientes de fiabilidad entre .78 y .84. Solo ocho artículos aportan datos sobre la fiabilidad de la escala total con una media de .90. De los 26 estudios que realizaron un análisis factorial, 18 confirman la estructura de seis factores original (AU)

Volunteer Functions Inventory: A systematic review.

The objective of this research study was to conduct a systematic review of the research on volunteers using Clary et al.’s VFI (1998). A total of 48 research studies including 67 independent samples met eligibility criteria. The total sample of the studies analyzed ranged from 20375 to 21988 participants, depending on the motivation analyzed. The results show that the Values factor obtained the highest mean score, both overall and in each type of volunteering, whereas the lowest scores were for the Career and Enhancement factors. Studies conducted with samples with a mean age under 40 years obtain higher scores on Career and Understanding scales when compared to studies in older samples. The group of studies with less than 50% women yield higher mean scores on the Social scale than studies with more than 50% women in the sample. All the scales show reliability coefficients between .78 and .84. Only eight of the articles provide data on the reliability of the scale with a mean value of .90. Of the 26 studies that performed factor analysis, 18 confirmed the original structure of six factors.

Transdiagnostic Cognitive Behavioral Therapy Versus Treatment as Usual in Adult Patients With Emotional Disorders in the Primary Care Setting (PsicAP Study): Protocol for a Randomized Controlled Trial.

BACKGROUND: Demand for primary care (PC) services in Spain exceeds available resources. Part of this strong demand is due to the high prevalence of emotional disorders (EDs)-anxiety, depression, and somatic symptom disorders-and related comorbidities such as pain or chronic illnesses. EDs are often under- or misdiagnosed by general practitioners (GPs) and, consequently, treatment is frequently inadequate. OBJECTIVE: We aim to compare the short- and long-term effectiveness of group-delivered transdiagnostic cognitive behavioral therapy (TD-CBT) versus treatment as usual (TAU) in the treatment of EDs in the PC setting in Spain. We also aim to compare the effect of these treatments on disability, quality of life, cognitive-emotional factors, and treatment satisfaction. METHODS: Here we present the study design of a two-arm, single-blind, randomized controlled trial (N=1126) to compare TAU to TD-CBT for EDs. TAU will consist primarily of pharmacological treatment and practical advice from the GP while TD-CBT will be administered in seven 90-minute group sessions held over a period ranging from 12 to 14 weeks. Psychological assessments are carried out at baseline (ie, pretreatment); posttreatment; and at 3-, 6-, and 12-month follow-up. The study is conducted in approximately 26 PC centers from the National Health System in Spain. RESULTS: This study was initiated in December 2013 and will remain open to new participants until recruitment and follow-up has been completed. We expect all posttreatment evaluations to be completed by December 2017, and follow-up will end in December 2018. CONCLUSIONS: We expect the TD-CBT group to have better results compared to TAU on all posttreatment measures and that this improvement will be maintained during follow-up. This project could serve as a model for use in other areas or services of the National Health System in Spain and even in other countries. CLINICALTRIAL: International Standard Randomized Controlled Trial Number (ISRCTN): 58437086; http://www.isrctn.com/ISRCTN58437086 (Archived by WebCite at http://www.webcitation.org/6mbYjQSn3).

An Explanatory Model of Poverty from the Perspective of Social Psychology and Human Rights.

Poverty is a social problem, entailing not only an economical perspective but above all a human and social issue. Poverty is promoted, justified and maintained by unique individuals and groups by means of our own attitudes, interests and behavior, as well as with our social structures and social relationships. From this interactive, psychosocial and sociostructural perspective, and also considering poverty as a denial of basic human rights (UNDP, 1998), we carried out a study with the primary objective to design and verify an Explanatory Model of Poverty. This research may helps to increase the validity of diagnostics and the effectiveness of interventions. Most of the hypotheses were accepted during the analysis and verification of the Model (p < .001), with data fitting the Model (CFI: 1 RMSEA: .025: LO90: 0 - HI90: .061. RMR: .008). These results, if replicated in new investigations, could have the following implications: (a) the need for a broad and comprehensive definition of poverty including its effects, processes and causes; (b) the need for everybody to accept the social responsibility in the prevention and solution to poverty; and

An explanatory model of poverty from the perspective of social psychology and human rights

Poverty is a social problem, entailing not only an economical perspective but above all a human and social issue. Poverty is promoted, justified and maintained by unique individuals and groups by means of our own attitudes, interests and behavior, as well as with our social structures and social relationships. From this interactive, psychosocial and sociostructural perspective, and also considering poverty as a denial of basic human rights (UNDP, 1998), we carried out a study with the primary objective to design and verify an Explanatory Model of Poverty. This research may helps to increase the validity of diagnostics and the effectiveness of interventions. Most of the hypotheses were accepted during the analysis and verification of the Model (p< .001), with data fitting the Model (CFI: 1 RMSEA: .025: LO90: 0 - HI90: .061. RMR: .008). These results, if replicated in new investigations, could have the following implications: (a) the need for a broad and comprehensive definition of poverty including its effects, processes and causes; (b) the need for every -body to accept the social responsibility in the prevention and solution to poverty; and (c) the need to conduct longitudinal interventions with scientific methodology and social participation (AU)

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Is engagement different from satisfaction and organizational commitment? Relations with intention to remain, psychological well-being and perceived physical health in volunteers / ¿Es el engagement diferente de la satisfacción y del compromiso organizacional? Relaciones con la intención de permanencia, el bienestar psicológico y la salud física percibida en voluntarios

En una muestra de voluntarios, que trabajan, aunque no por dinero, y cuyos gestores esperan que permanezcan en la organización por largo tiempo y sintiéndose bien ayudando a otras personas, el presente estudio analiza la distintividad entre tres conceptos frecuentemente relacionados entre sí en el área de la Psicología del trabajo: engagement, compromiso organizacional y satisfactión. Basándose en la literatura existente, se proponen relaciones entre ellos y respecto a tres resultados finales relevantes para la gestión del voluntariado: intención de permanencia, bienestar psicológico y salud física percibida. Tres modelos de ecuaciones estructurales dejan claro que el engagement en el voluntariado contribuye a explicar el compromiso organizacional, la satisfacción y el bienestar psicológicos de los voluntarios, al mismo tiempo que no parece explicar ni la intención de permanencia ni la salud física percibida. Por el contrario, el compromiso organizacional es el único predictor de la intención de permanencia y la satisfacción en el voluntariado es el único predictor de la salud física percibida. Este último resultado no era el esperado, según la bibliografía existente en el área del trabajo, aunque viene a reforzar la diferenciación entre los tres conceptos y puede además tener una explicación plausible en el área del voluntariado (AU)

In a sample of volunteers, who work, but not for money, and whose managers expect them to remain with the organization over the long term and to feel well by doing good, this study examines the distinctiveness between three concepts, usually related in the work field: Engagement, organizational commitment, and satisfaction. Based on the existing literature, they are related among them and regarding three relevant outcomes for management: Intention to remain, psychological well-being, and perceived physical health. Three structural equations models make it clear that volunteer engagement does contribute to the explanation of organizational commitment, volunteer satisfaction, and psychological well-being. At the same time, it does not seem to account for levels of intention to remain neither perceived physical health. On the contrary, organizational commitment is the only predictor of intention to remain, and volunteer satisfaction is the only predictor of perceived physical health. This last result was not expected, according to the literature on work, but reinforces the distinctiveness between the concepts and may have a plausible explanation in the volunteering field (AU)

Efficacy of lifestyle interventions in physical health management of patients with severe mental illness.

Awareness of the importance of maintaining physical health for patients with severe mental illnesses has recently been on the increase. Although there are several elements contributing to poor physical health among these patients as compared with the general population, risk factors for cardiovascular disease such as smoking, diabetes mellitus, hypertension, dyslipidemia, metabolic syndrome, and obesity are of particular significance due to their relationship with mortality and morbidity. These patients present higher vulnerability to cardiovascular risk factors based on several issues, such as genetic predisposition to certain pathologies, poor eating habits and sedentary lifestyles, high proportions of smokers and drug abusers, less access to regular health care services, and potential adverse events during pharmacological treatment. Nevertheless, there is ample scientific evidence supporting the benefits of lifestyle interventions based on diet and exercise designed to minimize and reduce the negative impact of these risk factors on the physical health of patients with severe mental illnesses.

Epidemiology of foreign bodies injuries in Ecuador: a first look based on a single centre experience.

OBJECTIVE: The analysis of foreign bodies (FB) injuries in the upper aero-digestive tract is not available for Ecuador and in this context, the present article represent the is the first presenting to the international community the basic epidemiological data on the Ecuador's experience on foreign bodies juries. METHODS: Data on 258 cases were gleaned using Susy Safe database, choosing the cases coming from Ecuador's institutions, namely Francisco De Icaza Bustamante Children Hospital, in Guayaquil (Ecuador) which collects data on children injuries due to foreign bodies with the aid of a standardized case report forms. RESULTS: Patients showed a female:male ratio of 1:1.2. Fifty-three percent of the children were younger than 2 years of age, with a mean age of 3.22 years. The most frequent location of retrieval was the oesophagus (37.98%) followed by the ears (34.88%). Coins were the most frequent cause of accident (37.21%). Seeds and grain were the most frequent food FBs and they were seen in 13.95% of cases. Adult presence was recorded in 113 cases. There was indeed a significant correlation between the presence of an adult and the activity that the children were doing when the incident occurred. CONCLUSIONS: This first breach into the analysis of injuries in Ecuador gives the confirmation that the results coming from country's data agreed with the general Susy Safe ones. Similar preventive strategies are therefore highly recommended, stressing that primary prevention has the main role in children's protection.

Motivos del Voluntariado: Categorización de las Motivaciones de los Voluntarios Mediante Pregunta Abierta / Motives for Volunteering: Categorization of Volunteers’ Motivations Using Open-ended Questions

La mayoría de los estudios sobre motivaciones del voluntariado utilizan cuestionarios estandarizados, siendo el Volunteer Funcion Inventory (VFI) el más utilizado. En muy pocas ocasiones se pregunta de forma abierta a los voluntarios por los motivos que les llevan a serlo. En este trabajo hipotetizamos que los cuestionarios tiende a sobre estimar el número de motivaciones y a infraestimar la variedad de las mismas, por lo que se analizan las respuestas cualitativas de 1515 voluntarios a una pregunta abierta por sus motivaciones y se realiza una categorización de las mismas. Los resultados muestran que los voluntarios dan una media de dos motivos, muy por debajo de lo aportado por los cuestionarios, y que Valores es la motivación más frecuentemente citada y la considerada másimportante por la mayoría. Además, esta motivación parece coexistir con otras motivaciones muy diversas, no contempladas en los cuestionarios, como Compromiso Organizacional, Religiosidad, Cambio Social, Interés por la Actividad o Desarrollo Personal (AU)

Most studies of volunteers’ motivations use standardized questionnaires with one of the most commonly-used being the Volunteer Function Inventory. Open-ended questions about what drives individuals to be volunteers are seldom used. We hypothesize that questionnaires tend to overestimate the numberof motivations and to underestimate their variety. Therefore, in this paper we analyze the answers of1515 volunteers to an open-ended question and categorize these answers. Results show that volunteers give an average of 2 motivations, fewer than the questionnaires, and that the Value motivation is the most frequently mentioned and the most important for volunteers. In addition, thismotivation coexists with other motivations, which are lacking in the standard questionnaires, such as Organizational Commitment, Personal Development, Religiosity, Social Change or Interest in the Activity (AU)

Effect of social isolation on 24-h pattern of stress hormones and leptin in rats.

This work analyzes the effect of social isolation of growing male rats on 24-h changes of plasma prolactin, growth hormone, ACTH and leptin, and on plasma and adrenal corticosterone concentrations. At 35 days of life, rats were either individually caged or kept in groups (6-8 animals per cage) under a 12:12 h light/dark schedule (lights on at 08:00 h). A significant arrest of body weight gain regardless of unchanged daily food intake was found in isolated rats after 2 weeks of isolation. On the 4th week, rats were killed at 6 time intervals during a 24-h cycle, beginning at 09:00 h. In isolated rats the 24-h pattern of all parameters tested became distorted, as assessed by Cosinor analysis. When analyzed as a main factor in a factorial analysis of variance, isolation decreased plasma prolactin and growth hormone, increased plasma leptin and corticosterone while decreased adrenal corticosterone. Plasma corticosterone levels correlated significantly with plasma ACTH and with adrenal corticosterone levels in group-caged rats only. These changes can be attributed to an effect of mild stress on the endogenous clock that modulates the circadian hormone release.

24-hour changes in ACTH, corticosterone, growth hormone, and leptin levels in young male rats subjected to calorie restriction.

Calorie restriction of young male rats increases plasma prolactin, decreases luteinizing hormone (LH) and testosterone, and disrupts their 24 h secretory pattern. To study whether this could be the consequence of stress, we examined the 24 h variations of plasma adrenocorticotropic hormone (ACTH) corticosterone, growth hormone (GH), leptin, and adrenal corticosterone. Rats were submitted to a calorie restriction equivalent to a 66% of usual intake for 4 weeks, starting on day 35 of life. Controls were kept in individual cages and allowed to eat a normal calorie regimen. Significantly lower ACTH levels were detected in calorie-restricted rats. Plasma corticosterone levels during the light phase of the daily cycle were significantly higher in calorie-restricted rats. Time-of-day variation in plasma ACTH and corticosterone levels attained significance in calorie-restricted rats only, with a maximum toward the end of the resting phase. The daily pattern of adrenal gland corticosterone mirrored that of circulating corticosterone; however, calorie restriction reduced its levels. Plasma ACTH and corticosterone correlated significantly in controls only. Calorie restriction decreased plasma GH and leptin, and it distorted 24h rhythmicity. In a second study, plasma ACTH and corticosterone levels were measured in group-caged rats, isolated control rats, and calorie-restricted rats during the light phase of the daily cycle. Plasma ACTH of calorie-restricted rats was lower, and plasma corticosterone was higher, compared with isolated or group-caged controls. The changes in the secretory pattern of hormones hereby reported may be part of the neuroendocrine and metabolic mechanisms evolved to maximize survival during periods of food shortage.

24-hour pattern of circulating prolactin and growth hormone levels and submaxillary lymph node immune responses in growing male rats subjected to social isolation.

To assess the effect of social isolation of growing rats on 24-h rhythmicity of circulating prolactin and growth hormone (GH) levels and submaxillary lymph node immune responses, male Wistar rats were either individually caged or kept in groups (4-5 animals per cage) for 30 d starting on d 35 of life. Plasma prolactin and GH levels, and submaxillary lymph node lymphocyte subset populations, interferon (IFN)-gamma release and mitogenic responses to concanavalin A (Con A) and lipopolysaccharide (LPS) were determined at six time intervals during the 24 h span. Social isolation brought about changes in mean values and 24-h pattern of plasma prolactin and GH levels and lymph node immune responses. After isolation, prolactin and GH mean values decreased, and lymph node T, B, non T-non B, CD8+, and CD4+-CD8+ cells augmented, whereas lymph node CD4+/CD8+ ratio, IFN-gamma release and mitogenic responses decreased. Social isolation resulted in disruption of 24 h rhythmicity of every immune parameter tested. CD4+/CD8+ ratio, IFN-gamma release and Concanavalin A (Con A) and lipopolysaccharide (LPS) responses correlated significantly with plasma prolactin or GH levels while T/B ratio correlated with plasma prolactin levels only. B, non T-non B, and CD4+-CD8+ cells correlated negatively with plasma prolactin. Modifications in mean value and 24-h rhythmicity of plasma prolactin and GH levels are presumably involved in the effect of social isolation on immune responsiveness.

Twenty-four-hour rhythms of mitogenic responses, lymphocyte subset populations and amino acid content in submaxillary lymph nodes of growing male rats subjected to calorie restriction.

Peripubertal male Wistar rats were submitted to a calorie restriction diet enriched in proteins and low in fat and carbohydrates for 4 weeks, and starting on day 35 of life. Mitogenic responses, lymphocyte subset populations, interferon (IFN)- gamma release and amino acid content were determined in submaxillary lymph nodes at six time intervals during the 24-h span. The diet employed completely arrested growth in growing rats. After caloric restriction, mean values of Con A response, lymph node T and CD4+ cell number and CD4+/CD8+ ratio augmented, whereas those of B cell number, IFN-gamma release and glutamine and glutamate concentration decreased. Calorie restriction modified 24-h rhythmicity of lymph node mitogenic responses to Con A and LPS, and of T, T-B, CD4+ and CD4+ -CD8+ lymph node cell subsets. It also changed the 24-h pattern of lymph node IFN-gamma release and glutamine, aspartate, glutamate and taurine lymph node content. Availability of nutrients presumably affects the mechanisms that modulate the circadian variation of immune responsiveness in growing rats.

24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone, and testosterone in young male rats subjected to calorie restriction.

This work analyzes the effect of calorie restriction on the 24h variation of pituitary-testicular function in young male Wistar rats by measuring the circulating levels of prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Control animals were provided an equilibrium calorie diet and the experimental animals a calorie-restriction diet equivalent to 66% of food restriction for four weeks starting on day 35 of life. Different groups of control and experimental rats were killed at 6h intervals around the clock, beginning I h after light on (HALO). Compared to the control animals, the mean secretion of prolactin was augmented and that of LH and testosterone decreased in calorie-restricted rats, whereas FSH release remained unchanged. Significant changes in the 24 h secretory pattern of circulating prolactin, LH, and testosterone occurred in the calorie-restricted rats. These include the appearance of a second maximum of plasma prolactin at 21 HALO, blunting of the LH peak seen at 13 HALO, and phase-shift of the testosterone peak from 13 HALO in controls to 17 HALO in calorie-restricted rats. The significant positive correlation between individual LH and testosterone levels found in controls was no longer observed in calorie-restricted rats. Availability of nutrients presumably affects the mechanisms that modulate the circadian variation of the pituitary-gonadal axis in growing male rats.

Differential responses of circulating prolactin, GH, and ACTH levels and distribution and activity of submaxillary lymph node lymphocytes to calorie restriction in male Lewis and Wistar rats.

OBJECTIVES: Calorie restriction has been associated with anorexia in growing individuals, but the mechanisms involved are not known. Also, the effects of carbohydrates and lipid restriction in growing individuals were not studied. The aim of this study was to determine whether 66% calorie restriction (lipids and carbohydrates) differentially affects growing rats of the Wistar or Lewis strains. METHODS: Growing male Wistar and Lewis rats were subjected to 66% calorie restriction for 4 weeks. Plasma prolactin, growth hormone (GH), and adrenocorticotropic hormone (ACTH) levels were measured by specific radioimmunoassays. Likewise, lymphocytes from submaxillary lymph nodes were aseptically obtained to study absolute number of lymphocytes, cell surface markers (CD4+, CD8+, CD4+CD8+, B, and T cells), and proliferation. RESULTS: The body weight gain was lower in Lewis than in Wistar rats and was blunted in both strains by calorie restriction. Wistar and Lewis rats exhibited differential patterns of plasma prolactin, ACTH, and GH levels as well as proliferative capacities of T and B cells and their distribution in the submaxillary lymph nodes. Calorie restriction increased plasma prolactin and ACTH levels in Lewis as compared with Wistar rats. However, the plasma GH levels were diminished in both strains of rats by calorie restriction. All changes in plasma prolactin ACTH and GH levels seemed to correlate with the modifications observed in the distributions of T and B subsets in the submaxillary lymph nodes as well as in their proliferative capacity. CONCLUSIONS: Calorie restriction differentially modifies the secretory patterns of prolactin, GH, and ACTH in Lewis and in Wistar rats. These changes may explain, at least in part, the associated modifications in the proliferative capacity of submaxillary lymph node lymphocytes and in their distribution.

d24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone and testosterone in male rats subjected to social isolation.

BACKGROUND: This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone. METHODS: Animals were either individually caged or kept in groups (4-5 animals per cage) under a 12:12 h light-dark cycle (lights on at 0800 h) for 30 days starting on day 35 of life. Rats were killed at 4-h intervals during a 24-h cycle, beginning at 0900 h. RESULTS: Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion. In isolated rats the 24-h secretory pattern of prolactin and testosterone became modified, i.e., the maximum in prolactin seen in control animals at the beginning of the activity span was no longer detected, whereas the maximum in circulating testosterone taking place at 1700 h in controls was phase-delayed to 2100 h in isolated rats. CONCLUSION: Social isolation affects the 24-h variation of pituitary-testicular function in young rats. Secretion of prolactin, LH and testosterone decreases, and secretion of FSH increases, in isolated rats. The maximum in prolactin seen in group-caged rats at the beginning of the activity span is not observed in isolated rats. The maximum in circulating testosterone taking place at the second part of the rest span in controls is phase-delayed to the light-dark transition in isolated rats.