Powerlessness Regarding Health-Service Barriers: Construction of an Instrument

PURPOSE. The purpose of the study was to develop a scale to calculate college students' powerlessness regarding health service barriers (PHSB). METHODS. Scale items were generated to represent two domains of interest: powerlessness and college students' powerlessness regarding health service barriers. The final 20-item instrument was subjected to multiple measures of validity with college students and panels of nurse experts in the area of nursing diagnosis. Reliability was assessed by two samples (n = 92 and n = 33) of college-age students. A final administration was conducted with 197 college students. FINDINGS. The PHSB scale was determined to be an accurate and consistent measure. CONCLUSIONS. This instrument will provide a reliable and valid measure to conduct research.     

Histidine, histamine, and the neuroregulation of food intake: a review and hypothesis

Feeding, a behavior regulated by the central nervous system (CNS), includes the acquisition of specific essential nutrients and the maintenance of energy balance. Modulation of feeding behavior is a normal part of survival, but certain pathological conditions interrupt or modify regulatory aspects of feeding, thereby leading to inappropriate intake. This review examines aspects of metabolism associated with the anorexia seen in animals suffering from protein-energy malnutrition (PEM). The main focus is the indispensable amino acid histidine (His), the biosynthetic precursor of the neurotransmitter histamine (HA). In kwashiorkor-like PEM, His is elevated in plasma and brain, whereas all other indispensable amino acids are decreased. The elevation of His in the brain is to concentrations five times normal. Because the rate of HA synthesis in the brain is a function of the His concentration, His elevation raises the possibility of a profound direct effect of CNS function. In children, PEM consistently produces the symptoms of depressed food intake, edema, growth failure, and psychomotor changes. One known central effect of HA is the stimulation of ACTH and corticosteroid release. Based on these observations, the hypothesis being examined is as follows: one component of the pathophysiological neuroregulation of food intake involved the His-induced variation of HA concentration in the hypothalamus and the subsequently altered neurochemical activity at the corticotropin-releasing factor (CRF) neurons o the paraventricular nucleus (PVN).     

Theophylline and status epilepticus in children

We studied the role of theophylline on outcome of status epilepticus (SE) in children. During a two-year-period, 16 of 114 episodes of SE occurred in children receiving theophylline. At the onset of SE, theophylline blood levels were elevated in 8 episodes, and were therapeutic or subtherapeutic in 8 episodes. In the 8 episodes of SE with elevated theophylline levels, one child died and three suffered permanent new neurologic deficits. In the 8 episodes of SE with normal or low theophylline levels, only one child had a transient deficit. The occurrence of death or disability in 4 of 8 episodes of SE with elevated theophylline was considerably higher than the 23% incidence of death or persistent CNS deficit in the overall series of 114 episodes of SE. We conclude that theophylline, at toxic levels, is a significant factor in increased morbidity. We suspect that the hypoxia from the respiratory disorder for which theophylline was used, and the reduced cerebral blood flow known to occur with theophylline led to a failure to compensate for the increased cerebral metabolic rate of SE, thus increasing the risk of a poor outcome.     

Expression of functional postjunctional alpha 2-adrenoceptors in rabbit isolated distal saphenous artery--a permissive role for angiotensin II?

In the rabbit isolated distal saphenous artery, the population of postjunctional adrenoceptors is of the alpha 1 variety under normal in vitro experimental conditions, based on the potency order of selective agonists and on the effects of the antagonists prazosin and rauwolscine against responses to UK-14304. Angiotensin II (A II, 0.05 microM) however, without affecting resting baseline tension, markedly enhanced responses to UK-14304, particularly at low concentrations. This previously unseen component of the response to UK-14304 was resistant to prazosin (0.1 microM) but susceptible to rauwolscine (1 microM). A II would therefore appear to have a permissive role for the expression of a quiescent population of postjunctional alpha 2-adrenoceptors in the rabbit distal saphenous artery.     

Macrophages and translymphatic absorption represent the first line of host defense of the peritoneal cavity

To quantitate the host defenses of the rat peritoneal cavity, nonviable radiolabeled Escherichia coli were injected intraperitoneally and clearance, leukocyte influx, and phagocytosis were examined. Macrophages (MCs) were present initially and remained relatively constant in number. The polymorphonuclear leukocyte (PMN) response began at one to two hours and was maximal at 24 to 72 hours. A previously unidentified inoculum-dependent PMN response was defined. Clearance and phagocytosis were extremely rapid, and few (less than 3%) free bacteria were present after two hours. Phagocytic activity of MCs and PMNs was identical, but MCs were numerically predominant initially and thus accounted for the majority of early phagocytosis. Thus, MC phagocytosis and clearance represent the primary line of host peritoneal defenses. We hypothesize that the subsequent inoculum-dependent PMN response may have evolved to cope with those larger inocula for which this initial response is inadequate.