Developing the research pipeline: increasing minority nursing research opportunities

The need to increase the number of minority nurses in policy and leadership positions in health care administration, academia, and research has been acknowledged. Limited academic and research training opportunities are available specifically designed to develop a cadre of minority nurse scientists to conduct the research needed to ultimately reduce health disparities within racial and ethnic minority populations. This article describes a collaborative approach to research career development at the doctoral level.     

Sympathetic augmentation in hypertension: role of nerve firing, norepinephrine reuptake, and Angiotensin neuromodulation

There is growing evidence that essential hypertension is commonly neurogenic and is initiated and sustained by sympathetic nervous system overactivity. Potential mechanisms include increased central sympathetic outflow, altered norepinephrine (NE) neuronal reuptake, diminished arterial baroreflex dampening of sympathetic nerve traffic, and sympathetic neuromodulation by angiotensin II. To address this issue, we used microneurography and radiotracer dilution methodology to measure regional sympathetic activity in 22 hypertensive patients and 11 normotensive control subjects. The NE transport inhibitor desipramine was infused to directly assess the potential role of impaired neuronal NE reuptake. To evaluate possible angiotensin sympathetic neuromodulation, the relation of arterial and coronary sinus plasma concentrations of angiotensin II to sympathetic activity was investigated. Hypertensive patients displayed increased muscle sympathetic nerve activity and elevated total systemic, cardiac, and renal NE spillover. Cardiac neuronal NE reuptake was decreased in hypertensive subjects. In response to desipramine, both the reduction of fractional transcardiac 3[H]NE extraction and the increase in cardiac NE spillover were less pronounced in hypertensive patients. DNA sequencing analysis of the NE transporter gene revealed no mutations that could account for reduced transporter activity. Arterial baroreflex control of sympathetic nerve traffic was not diminished in hypertensive subjects. Angiotensin II plasma concentrations were similar in both groups and were not related to indexes of sympathetic activation. Increased rates of sympathetic nerve firing and reduced neuronal NE reuptake both contribute to sympathetic activation in hypertension, whereas a role for dampened arterial baroreflex restraint on sympathetic nerve traffic and a peripheral neuromodulating influence of angiotensin II appear to be excluded.     

Experimental infection of the olive baboon (Paplio anubis) with Plasmodium knowlesi: severe disease accompanied by cerebral involvement

Experimental systems that model some of the complex interactions between parasite and host can be extremely valuable in identifying and developing new prophylactics and therapeutics against human diseases. Because primates have similar immune systems to humans, we have characterized a baboon model for understanding host response to Plasmodium knowlesi. Ten intact olive baboons (Papio anubis) of either sex were experimentally infected with P. knowlesi H strain erythrocytic parasites. The infection in these baboons was either acute or chronic. Animals with acute infection developed multiple system organ dysfunction and cerebral involvement. In chronically infected animals, only the spleen was moderately enlarged. The P. knowlesi parasitemia profile in baboons and rhesus monkeys was comparable. However, some clinical symptoms of the baboons and P. falciparum-infected humans were similar. These studies demonstrate for the first time that P. anubis is a suitable host for P. knowlesi for studying clinical symptoms and pathology.     

Continuous care teams in intensive outpatient treatment of chronic mentally ill patients

A continuous care team provides ongoing treatment for chronic mentally ill patients at a community mental health center in an inner-city area. The team, which consists of a nurse-social worker, a psychiatrist, four clinicians, and an addictions counselor, uses aggressive outreach and remains in charge of treatment while the patient is hospitalized. Preliminary outcomes for 32 of 39 patients treated during the first 15 months of the program included increased rates of treatment compliance, decreased frequency of crises, and decreased frequency and duration of hospitalization. However, substance abuse continued to be a problem and was negatively correlated with improvement.     

Olfactory primary neurons as a route of entry for toxic agents into the CNS.

Reports in the literature suggest that the primary sensory neurons of the olfactory system may provide a direct route of entry for agents into the central nervous system (CNS). To investigate whether cadmium, a heavy metal which is normally excluded from the CNS by the blood-brain barrier, can enter the CNS via the olfactory system, rats were exposed either intranasally (unilaterally) or ip to 109Cd (1 mumol Cd labeled with 1 microCi 109Cd). Rats were allowed to survive 7 days, at which point they were euthanized and the kidneys, livers, right and left forebrains, right and left olfactory bulbs, and right and left olfactory epithelia were removed. Tissues were placed in scintillation vials and radioactivity counted. In rats exposed by intranasal instillation, Cd levels were significantly elevated in the kidney, liver and ipsilateral olfactory bulb and epithelium, but not in the contralateral bulb and epithelium or forebrain areas. With the ip exposure, Cd levels were only elevated in the kidney and liver. In a second study the protocol was repeated (without ip exposure), but the olfactory bulbs and epithelium were washed in EDTA before counting. Cd was still present in the bulbs after washing, suggesting that the metal was internal and not bound to the external membrane. In the final experiment, both time course and dose effect of this phenomenon were explored. Rats were exposed either intransally to 1 mumol Cd labeled with 109Cd (1 microCi) and then sacrificed after 1, 3, 7, or 14 days or were exposed to 0.01, 0.1, or 1.0 mumol Cd labeled with 1 microCi 109Cd and sacrificed after 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)     

Listeria monocytogenes--an unusual cause of late infection in a prosthetic hip joint

As the scope of patients having arthroplasty with compromised immune systems expands, the incidence of late prosthetic infections will increase and the variety of infecting organisms will broaden. The role of prophylactic antibiotics for such patients undergoing procedures known to cause a transient bacteremia is currently unknown. Their use is not universal and many patients undergo procedures frequently without any form of protection. The following case report outlines an unusual organism causing late hip arthroplasty infection in an immunocompromised host and examines the role of prophylactic antibiotics in preventing such complications.     

The Influence of Photoperiod on the Hypothalamic Content of Beta-Endorphin and the Luteinizing Hormone Responses to Naloxone and to Steroid Withdrawal in the Male Syrian Hamster

The aim of this study was to investigate the influence of inhibitory photoperiods upon opioidergic function, as determined by changes in the hypothalamic content of β-endorphin and the luteinizing hormone response to opioidergic receptor blockade, in the male Syrian hamster over the course of gonadal involution and spontaneous gonadal recrudescence. Animals exposed to an 8 h light: 16 h dark cycle (8L: 16D) for 14 weeks underwent gonadal regression. Regression was also observed in animals held for 7 weeks on one of a range of short daylengths of between 11.5 h and 13.5 h, the degree of atrophy being greatest in those animals on the shortest daylength. The tissue concentration of β-endorphin within the mediobasal hypothalamus was significantly higher in animals exposed to 8L: 16D for 14 weeks than in gonadally active controls held on long days (16L: 8D). Exposure to photoperiods of less than 13.5 h for 7 weeks also caused a significant increase in the β-endorphin content of the mediobasal hypothalamus and there was a positive correlation between the concentration of β-endorphin, the degree of gonadal atrophy and the shortness of the photoperiod. Endorphin levels within the preoptic area were not affected by photoperiodic treatments. Exposure of intact animals to 8L: 16D for 12 weeks caused gonadal atrophy and an associated loss of the luteinizing hormone responses to both naloxone and castration. Castrated animals receiving testosterone replacement (cast + T) also exhibited photoinhibition, in the form of reduced serum levels of luteinizing hormone, and this was similarly accompanied by a loss of sensitivity to naloxone and to withdrawal of steroid. Prolonged exposure to 8L:16D led to spontaneous reactivation of the gonadotrophic axis as a consequence of the development of scotorefractoriness. In both gondally intact animals and in cast + T groups, this was associated with a restoration, in parallel, of the luteinizing hormone responses to naloxone and to castration/ steroid withdrawal. The time-course of the restoration of the response to steroid withdrawal in castrates was not significantly different to that observed in intact animals. The luteinizing hormone response to naloxone took significantly longer to redevelop in cast + T groups than it did in gonadally intact animals. The data demonstrate that central opioid systems are sensitive to photoperiod and are consistent with the hypothesis that opioids are involved in the neuroendocrine regulation of reproductive responses to daylength.