The Effects of Stages of the Estrous Cycle on Pain Thresholds in Female White Rats

The effects of stages in the estrous cycle on electrical pain thresholds were studied in white rats in conditions of chronic measurement. On recording day 3, females in the diestrus and estrus stages showed sharp increases in shudder and paw-shuffling thresholds. Females in proestrus and metestrus showed no change in thresholds as compared with those in the first days of recording. Starting from day 7, there were progressive decreases in electrical pain thresholds regardless of the stage of the estrous cycle. Data for all animals showed that regular measurement of pain thresholds induces a smooth two-fold increase in body resistance from day 1 to day 7. This was followed by a sharp drop on day 8, with parallel decreases in body resistance and electrical pain thresholds. Thus, chronic measurement of electrical pain thresholds and body resistance changed in a complex fashion, and threshold values depended on the stage of the estrous cycle.     

Immunosuppressive Effects of Dietary Wortmannin on Rats and Mice

In order to assess the effects of the fungal toxin wortmannin on the immune system, rats and mice were fed wortmannin-containing cultures of Fusarium oxysporum for 1 or 2 weeks. Wortmannin caused significant decreases in thymic weight, thymic lymphocyte numbers, serum IgG and IgM levels, the primary humoral response to T-dependent and T-independent antigens and the proliferative response of spleen cells to pokeweed mitogen. In vitro administration of wortmannin did not produce evidence of cytotoxicity to spleen or thymus cells. The data indicate that wortmannin inhibits immune function in rats and mice and suggest that metabolic modification of the toxin is necessary for toxicity.     

频谱水对大鼠全血粘度和红细胞变形性的影响

目的 :研究频谱水改善血液粘度和红细胞变形性的作用 ,进一步了解频谱水改善微循环、减轻红细胞聚集作用机理。方法 :大鼠饮用频谱水 30天～ 6 0天 ,由尾静脉注入内毒素造成微循环障碍模型 ,由心脏取血 ,分别进行细胞电泳和全血粘度、血浆粘度、红细胞变形性的测定。结果 :饮用频谱水 30天～ 6 0天的大鼠血液粘度均比对照组低 ,红细胞电泳速度比对照组快 ,显示红细胞的表面电荷比对照组多 ,不易使红细胞聚集。红细胞变形性无明显差别。结论 :饮用经调剂后的频谱水有改善血液粘度的作用 ,能提高红细胞电泳速度 ,有利于血液的流动     

Animal models of early life stress: Implications for understanding resilience

In the mid‐1950s, Levine and his colleagues reported that brief intermittent exposure to early life stress diminished indications of subsequent emotionality in rats. Here we review ongoing studies of a similar process in squirrel monkeys. Results from these animal models suggest that brief intermittent exposure to stress promotes the development of arousal regulation and resilience. Implications for programs designed to enhance resilience in human development are discussed. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 402–410, 2010.     

Natural Pathogens of Laboratory Mice, Rats, and Rabbits and Their Effects on Research

Laboratory mice, rats, and rabbits may harbor a variety of viral, bacterial, parasitic, and fungal agents. Frequently, these organisms cause no overt signs of disease. However, many of the natural pathogens of these laboratory animals may alter host physiology, rendering the host unsuitable for many experimental uses. While the number and prevalence of these pathogens have declined considerably, many still turn up in laboratory animals and represent unwanted variables in research. Investigators using mice, rats, and rabbits in biomedical experimentation should be aware of the profound effects that many of these agents can have on research.     

频谱水对大鼠血浆白介素1、6和白细胞行为的影响

目的 :探讨频谱水对大鼠白介素 1、6(IL 1、IL 6)和白细胞行为的影响。方法 :静脉内注入内毒素造成炎症刺激模型 ,用生化方法检测血浆IL 1、IL 6的含量 ,用活体方法观察白细胞粘附、游出行为。结果 :实验组大鼠饮用频谱水 30、60天后 ,血浆IL 1、IL 6的含量比对照组高 ,白细胞粘附、游出的数量比对照组明显减少。对照组大鼠白细胞粘附、游出的数量较实验组明显增多 ,而血浆中IL 1、IL 6的含量比实验组低。结论 :频谱水能够提高血浆IL 1、IL 6的含量 ,显著减轻白细胞粘附及游出。     

Social Media Use in the United States: Implications for Health Communication

Background

Given the rapid changes in the communication landscape brought about by participative Internet use and social media, it is important to develop a better understanding of these technologies and their impact on health communication. The first step in this effort is to identify the characteristics of current social media users. Up-to-date reporting of current social media use will help monitor the growth of social media and inform health promotion/communication efforts aiming to effectively utilize social media.

Objective

The purpose of the study is to identify the sociodemographic and health-related factors associated with current adult social media users in the United States.

Methods

Data came from the 2007 iteration of the Health Information National Trends Study (HINTS, N = 7674). HINTS is a nationally representative cross-sectional survey on health-related communication trends and practices. Survey respondents who reported having accessed the Internet (N = 5078) were asked whether, over the past year, they had (1) participated in an online support group, (2) written in a blog, (3) visited a social networking site. Bivariate and multivariate logistic regression analyses were conducted to identify predictors of each type of social media use.

Results

Approximately 69% of US adults reported having access to the Internet in 2007. Among Internet users, 5% participated in an online support group, 7% reported blogging, and 23% used a social networking site. Multivariate analysis found that younger age was the only significant predictor of blogging and social networking site participation; a statistically significant linear relationship was observed, with younger categories reporting more frequent use. Younger age, poorer subjective health, and a personal cancer experience predicted support group participation. In general, social media are penetrating the US population independent of education, race/ethnicity, or health care access.

Conclusions

Recent growth of social media is not uniformly distributed across age groups; therefore, health communication programs utilizing social media must first consider the age of the targeted population to help ensure that messages reach the intended audience. While racial/ethnic and health status–related disparities exist in Internet access, among those with Internet access, these characteristics do not affect social media use. This finding suggests that the new technologies, represented by social media, may be changing the communication pattern throughout the United States.     

Toward an Animal Model for Antisocial Behavior: Parallels Between Mice and Humans

The goal of this article is to examine whether mouse lines genetically selected for short and long attack latencies are good animal models for antisocial behavior in humans. To this end, we compared male Short and Long Attack Latency mice (SAL and LAL, respectively) with the extremes of the Dunedin Multidisciplinary Health and Development Study (men who persistently displayed antisocial behavior [Persisters] and men who never manifested antisocial behavior [Abstainers]). Groups were compared on the basis of five distinct domains: aggression/violence, reproduction, cognition, behavioral disorders, and endophenotypes. Our observations point to considerable parallels between, on one side, SAL and Persisters, and, on the other side, between LAL and Abstainers (but to a lesser extent). We believe that SAL and LAL are good mouse models to study the development of antisocial behavior and will yield valuable and testable hypotheses with regard to the neurobiological and genetical architecture of antisocial behavior.     

Risk Assessment of Hymenoptera Re-Sting Frequency: Implications for Decision-Making in Venom Immunotherapy

Background: Venom immunotherapy is highly efficacious in preventing anaphylactic sting reactions. However, there is an ongoing discussion regarding patient selection and whether and how to apply a cost-benefit analysis of venom immunotherapy. In order to help decision-making, we investigated the re-sting frequency of hymenoptera-venom-allergic patients to single out those at high risk. Methods: In this retrospective study, re-sting data of 96 bee-venom-allergic patients and 95 vespid-venom-allergic patients living mainly in a rural area of Switzerland were analyzed. Hymenoptera venom allergy status was rated according to the classification system of H.L. Mueller [J Asthma Res 1966;3:331-333]. Different risk-groups were defined according to sting exposure and their median sting-free interval was calculated. Results: The risk factors for a wasp or bee re-sting were outdoor occupation, beekeeping and habitation close to a bee-house. Half of all vespid-venom-allergic outdoor workers were re-stung within 3.75 years compared to 7.5 years for indoor workers. Similarly, 50% of the bee-venom-allergic beekeepers or subjects with a bee-house in the vicinity suffered a bee re-sting within 5.25 years compared to 10.75 years for individuals who were not beekeepers. Conclusions: The high degree of exposure of vespid-venom-allergic outdoor workers and bee-venom-allergic beekeepers and subjects living close to bee-houses underlines the high benefit of venom immunotherapy for these patients even if they suffered a non-life-threatening grade II reaction. Yet, bee-venom-allergic individuals with no proximity to bee-houses and with an indoor occupation face a very low exposure risk, which justifies epinephrine rescue treatment for these patients especially if they have suffered from grade II sting reactions.     

Modulatory Effect of the Pesticide Captan on the Immune Response in Rats and Mice

The effect of short-term oral administration of captan, [N-(trirnethylthio)-4-cyclohexene-1,2-carboximidel on the immune response was studied in rats and mice. Animals were fed a diet with or without 0.3 % (w/w) of captan for 7, 14, 21 and 42 days. The SRBC-antibody formation was depressed by about 70 % in both species after 14 days of treatment. A release of inhibition occurred in mice at day 42. In a parallel manner, the lymphoblastic stimulation of splenic cells by PHA and by LPS was studied in captan-treated mice and their controls. The stimulation by PHA of splenic cells that were mainly T cells was clearly inhibited (45 %) by day 14 of captan ingestion. Thereafter, the inhibition was only partially released until day 42. B cells, stimulated by LPS, presented a decrease in stimulation in captan-treated mice, during the first week of diet (20 %). Then an important increase in the stimulation of these cells occurred at day 21 (85 %) followed by a return to the normal value at day 42. These results pointed out a clear depressive effect of captan-diet on the immune response of the animals. The inhibition of SRBC-antibody formation during the first stage of the treatment may be correlated to the inhibitory effect of captan on T cells, which were cooperative with B cells for the expression of SRBC-antibody synthesis. These effects were obtained at a level of captan which was considerably lower than the toxic dose.     

Inhibitory Effects of Anti-VEGF Antibody on the Growth and Angiogenesis of Estrogen-induced Pituitary Prolactinoma in Fischer 344 Rats: Animal Model of VEGF-targeted Therapy for Human Endocrine Tumors

Estrogen-induced pituitary prolactin-producing tumors (PRLoma) in F344 rats express a high level of vascular endothelial growth factor (VEGF) associated with marked angiogenesis and angiectasis. To investigate whether tumor development in E2-induced PRLoma is inhibited by anti-VEGF monoclonal antibody (G6-31), we evaluated tumor growth and observed the vascular structures. With simultaneous treatment with G6-31 for the latter three weeks of the 13-week period of E2 stimulation (E2+G6-31 group), the following inhibitory effects on the PRLoma were observed in the E2+G6-31 group as compared with the E2-only group. In the E2+G6-31 group, a tendency to reduction in pituitary weight was observed and significant differences were observed as (1) reductions in the Ki-67-positive anterior cells, (2) increases in TUNEL-positive anterior cells, and (3) repair of the microvessel count by CD34-immunohistochemistry. The characteristic “blood lakes” in PRLomas were improved and replaced by repaired microvascular structures on 3D observation using confocal laser scanning microscope. These inhibitory effects due to anti-VEGF antibody might be related to the autocrine/paracrine action of VEGF on the tumor cells, because VEGF and its receptor are co-expressed on the tumor cells. Thus, our results demonstrate that anti-VEGF antibody exerted inhibitory effects on pituitary tumorigenesis in well-established E2 induced PRLomas.     

Modulatory Effect of the Pesticide Captan on the Immune Response in Rats and Mice

Abstract

The effect of short-term oral administration of captan, [N-(trirnethylthio)-4-cyclohexene-1,2-carboximidel on the immune response was studied in rats and mice. Animals were fed a diet with or without 0.3 % (w/w) of captan for 7, 14, 21 and 42 days. The SRBC-antibody formation was depressed by about 70 % in both species after 14 days of treatment. A release of inhibition occurred in mice at day 42. In a parallel manner, the lymphoblastic stimulation of splenic cells by PHA and by LPS was studied in captan-treated mice and their controls. The stimulation by PHA of splenic cells that were mainly T cells was clearly inhibited (45 %) by day 14 of captan ingestion. Thereafter, the inhibition was only partially released until day 42. B cells, stimulated by LPS, presented a decrease in stimulation in captan-treated mice, during the first week of diet (20 %). Then an important increase in the stimulation of these cells occurred at day 21 (85 %) followed by a return to the normal value at day 42. These results pointed out a clear depressive effect of captan-diet on the immune response of the animals. The inhibition of SRBC-antibody formation during the first stage of the treatment may be correlated to the inhibitory effect of captan on T cells, which were cooperative with B cells for the expression of SRBC-antibody synthesis. These effects were obtained at a level of captan which was considerably lower than the toxic dose.     

Adverse Drug Reactions: Implications for Providers of Health Care

Adverse drug reactions are defined and examples are given. Four areas of concern are addressed, namely, defining drug reactions, identifying some of the factors contributing to the adverse drug reactions, implications of adverse drug reactions for health-care providers, and preventive measures which impact on the occurrence of adverse drug reactions. It is implied that increased knowledge and research are important factors in the control of these problems.     

Modernization of Native Healers: Implications for Health Care Delivery in Ghana

There are two major categories of traditional healers in contemporary Ghana. The traditionalists still adhere to the basic concepts and methods of traditional healing. A significant proportion of healers have, however, adopted a new approach to healing. These new-style healers are rejecting some of the traditional beliefs about etiology of illness, and are reorganizing their medical practice. They have more education, live in cities, and acquire “modern” medical knowledge through formal training at Traditional Medical Training Centers. This new development has had a significant impact on the contributions of traditional medicine in health care delivery in Ghana.