Nitric oxide inhibits the release of norepinephrine and dopamine from the medial basal hypothalamus of the rat.

Previous research indicates that norepinephrine and dopamine stimulate release of luteinizing hormone (LH)-releasing hormone (LHRH), which then reaches the adenohypophysis via the hypophyseal portal vessels to release LH. Norepinephrine exerts its effect via alpha 1-adrenergic receptors, which stimulate the release of nitric oxide (NO) from nitricoxidergic (NOergic) neurons in the medial basal hypothalamus (MBH). The NO activates guanylate cyclase and cyclooxygenase, thereby inducing release of LHRH into the hypophyseal portal vessels. We tested the hypothesis that these two catecholamines modulate NO release by local feedback. MBH explants were incubated in the presence of sodium nitroprusside (NP), a releaser of NO, and the effect on release of catecholamines was determined. NP inhibited release of norepinephrine. Basal release was increased by incubation of the tissue with the NO scavenger hemoglobin (20 micrograms/ml). Hemoglobin also blocked the inhibitory effect of NP. In the presence of high-potassium (40 mM) medium to depolarize cell membranes, norepinephrine release was increased by a factor of 3, and this was significantly inhibited by NP. Hemoglobin again produced a further increase in norepinephrine release and also blocked the action of NP. When constitutive NO synthase was inhibited by the competitive inhibitor NG-monomethyl-L-arginine (NMMA) at 300 microM, basal release of norepinephrine was increased, as was potassium-evoked release, and this was associated in the latter instance with a decrease in tissue concentration, presumably because synthesis did not keep up with the increased release in the presence of NMMA. The results were very similar with dopamine, except that reduction of potassium-evoked dopamine release by NP was not significant. However, the increase following incubation with hemoglobin was significant, and hemoglobin, when incubated with NP, caused a significant elevation in dopamine release above that with NP alone. In this case, NP increased tissue concentration of dopamine along with inhibiting release, suggesting that synthesis continued, thereby raising the tissue concentration in the face of diminished release. When the tissue was incubated with NP plus hemoglobin, which caused an increase in release above that obtained with NP alone, the tissue concentration decreased significantly compared with that in the absence of hemoglobin, indicating that, with increased release, release exceeded synthesis, causing a fall in tissue concentration. When NO synthase was blocked by NMMA, the release of dopamine, under either basal or potassium-evoked conditions, was increased. Again, in the latter instance the tissue concentration declined significantly, presumably because synthesis did not match release. Therefore, the results were very similar with both catecholamines and indicate that NO acts to suppress release of both amines. Since both catecholamines activate the release of LHRH, the inhibition of their release by NO serves as an ultra-short-loop negative feedback by which NO inhibits the release of the catecholamines, thereby reducing the activation of the NOergic neurons and decreasing the release of LHRH. This may be an important means for terminating the pulses of release of LHRH, which generate the pulsatile release of LH that stimulates gonadal function in both male and female mammals.     

Natural bioburden levels detected on rigid lumened medical devices before and after cleaning

Controversy exists concerning the degree of microbial contamination associated with the us of rigid lumened medical devices, the efficacy of standard cleaning techniques used to remove pathogenic microorganisms from lumen channels, and whether patients are placed at risk of cross infection because of microbial contamination. In this study the level and types of microorganisms found on rigid lumened medical devices before and after cleaning in a hospital environment were investigated. The bioburden level after clinical use was found to be relatively low, ranging from 10¹ to 10⁴ colony forming units (CFU) per device. After the instruments were cleaned, none of the devices studied contained bioburden levels greater than 10⁴ CFU and 83% had bioburden levels less than or equal to 10² CFU. The bioburden present before cleaning was comprised of organisms derived from the handling of the device, from the hospital environment, and from the patient. The bioburden present after cleaning was comprised of organisms typically derived from the handling of the device and from the hospital environment. The level of bioburden per device was also related to the anatomic site where the device was used, with lower numbers of organisms found on devices exposed to sterile body sites and the respiratory tract.     

Evaluation of a Community Health Worker Intervention to Reduce HIV/AIDS Stigma and Increase HIV Testing Among Underserved Latinos in the Southwestern U.S.

Objectives

Latinos are at an elevated risk for HIV infection. Continued HIV/AIDS stigma presents barriers to HIV testing and affects the quality of life of HIV-positive individuals, yet few interventions addressing HIV/AIDS stigma have been developed for Latinos.

Methods

An intervention led by community health workers (promotores de salud, or promotores) targeting underserved Latinos in three southwestern U.S. communities was developed to decrease HIV/AIDS stigma and increase HIV knowledge and perception of risk. The intervention was led by HIV-positive and HIV-affected (i.e., those who have, or have had, a close family member or friend with HIV/AIDS) promotores, who delivered interactive group-based educational sessions to groups of Latinos in Spanish and English. To decrease stigma and motivate behavioral and attitudinal change, the educational sessions emphasized positive Latino cultural values and community assets. The participant pool comprised 579 Latino adults recruited in El Paso, Texas (n=204); San Ysidro, California (n=175); and Los Angeles, California (n=200).

Results

From pretest to posttest, HIV/AIDS stigma scores decreased significantly (p<0.001). Significant increases were observed in HIV/AIDS knowledge (p<0.001), willingness to discuss HIV/AIDS with one''s sexual partner (p<0.001), and HIV risk perception (p=0.006). Willingness to test for HIV in the three months following the intervention did not increase. Women demonstrated a greater reduction in HIV/AIDS stigma scores when compared with their male counterparts, which may have been related to a greater increase in HIV/AIDS knowledge scores (p=0.016 and p=0.007, respectively).

Conclusion

Promotores interventions to reduce HIV/AIDS stigma and increase HIV-related knowledge, perception of risk, and willingness to discuss sexual risk with partners show promise in reaching underserved Latino communities.Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) has disproportionately affected U.S. Latinos during the last 25 years. Although Latinos constitute 16% of the U.S. population, they account for 19% of those living with HIV and 21% of new HIV infections.¹ Since 2006, the Centers for Disease Control and Prevention (CDC) has recommended HIV testing for all people aged 13–64 years.² However, nearly half (46%) of Latino adults aged 18–64 years have never been tested, compared with 23% of black and 50% of white adults.³ Additionally, HIV testing often occurs at a late stage among HIV-positive Latinos. More than one-third (36%) of HIV-positive Latinos were diagnosed with AIDS within one year of learning their HIV status, compared with 32% of white people and 31% of black people.³ Late HIV testing hinders treatment options and may contribute to unknowing HIV transmission.Factors contributing to low HIV testing rates among Latinos include poverty, lack of health-care access, and limited availability of culturally and linguistically responsive services.^1,4–6 HIV/AIDS stigma is another factor.^7,8 UNAIDS (Joint United Nations Programme on AIDS) defines HIV stigma as the “devaluation of people either living with or associated with HIV/AIDS.”⁹ Stigma often results from fears about HIV as well as the associations of HIV with stigmatized groups such as homosexuals, sex workers, and injection drug users.^9,10HIV/AIDS stigma has negative consequences both at a population level and for individuals who are its targets, including people living with HIV/AIDS. Stigmatizing attitudes toward people living with HIV/AIDS are associated with decreased HIV testing, limited utilization of HIV prevention services, and high-risk sexual behaviors.^7,10,11 Additionally, for people living with HIV/AIDS, the stigma associated with HIV/AIDS contributes to unwillingness to disclose HIV status, unsafe sexual behaviors, delays in care seeking, reduced treatment adherence, mental health issues, and difficulties obtaining social support.^9,11–14Despite significant implications, few interventions have been developed to reduce HIV/AIDS stigma.^10,11,15 Existing interventions have often focused on specific populations (e.g., university students and health-care providers), with few interventions focused on Latinos,^11,15,16 who have high levels of stigmatizing attitudes toward people living with HIV/AIDS^1,17,18 that contribute to negative outcomes.^7,19Among Latinos, research indicates that community health workers (promotores de salud, hereinafter “promotores”) are an effective and culturally acceptable means of reaching the population with health information and motivating health behaviors.^20,21 Promotores are well positioned to promote changes in their communities because they share language and cultural values, are held in high esteem, and are perceived as role models.²¹ Promotores have been used to address health conditions ranging from chronic diseases to preventive screenings.^20–22 Several interventions have incorporated promotores into HIV prevention, finding significant changes in HIV risk behaviors, HIV counseling and testing, and other psychosocial constructs important to prevention.^16,23–29 To date, few studies have used promotores in interventions to reduce HIV stigma among Latinos.¹⁶We describe and report findings of an intervention using promotores to reduce HIV/AIDS stigma and increase willingness to seek HIV testing among Latinos in three communities in the southwestern United States: Los Angeles, California; San Ysidro, California; and El Paso, Texas.     

Population-Based Study of Trachoma in Guatemala

Abstract

Purpose: A prevalence survey for active trachoma in children aged under 10 years and trichiasis in women aged 40 years and older was carried out in four districts in the Sololá region in Guatemala, which is suspected of still having a trachoma problem.

Methods: Population-based surveys were undertaken in three districts, within 15 randomly selected communities in each district. In addition, in a fourth district that borders the third district chosen, we surveyed the small northern sub-district, by randomly selecting three communities in each community, 100 children aged under 10 years were randomly selected, and all females over 40 years. Five survey teams were trained and standardized. Trachoma was graded using the World Health Organization simplified grading scheme and ocular swabs were taken in cases of clinical follicular or inflammatory trachoma. Prevalence estimates were calculated at district and sub-district level.

Results: Trachoma rates at district level varied from 0–5.1%. There were only two sub-districts where active trachoma approached 10% (Nahualá Costa, 8.1%, and Santa Catarina Costa, 7.3%). Trichiasis rates in females aged 40 years and older varied from 0–3%. Trachoma was likely a problem in the past.

Conclusions: Trachoma is disappearing in the Sololá region in Guatemala. Health leadership may consider further mapping of villages around the areas with an especially high rate of trachoma and infection, and instituting trichiasis surgery and active trachoma intervention where needed.