Neurocognitive problems in attention deficit disorder. Alternative concepts and evidence for impairment in inhibition of selective attention.

The critical neurocognitive components of Attention-Deficit/Hyperactivity Disorder (ADHD) remain controversial, despite extensive research to disclose the essential cognitive components of this disorder. We propose to organize this research into three types of cognitive mechanisms while demonstrating the consistencies and inconsistencies in each: studies of response inhibition, of executive function, and of attentional inhibition. We also present the results of cluster analyses of a group (n = 25) of narrowly selected adult patients with childhood onset of ADHD, reveal three subtypes of ADHD, and argue that the only evidence of a general cognitive deficit is found in tests of selective attention. Finally, we provide the results of exploratory studies of selective attention for perception and for semantic memories. The data suggest that the cognitive disinhibition of ADHD is found in semantic recognition, but not in visuoperceptual recognition.

Alternative therapies and nurse practitioners: knowledge, professional experience, and personal use.

An anonymous questionnaire was mailed to all members of the Connecticut Nurse Practitioner Group, Inc. to identify their knowledge, and personal and professional experiences with alternative therapies. Of the 202 respondents (a 73% return), 78% described themselves as "slightly" or "quite" knowledgeable about alternative therapies in general and 63% reported personal experience. Approximately half of the nurse practitioners (NP) (49%) indicated they "sometimes" or "usually" ask about their clients' use of such therapies and 65% have referred for or recommended one or more of these modalities. Additionally, some NPs have provided alternative therapies directly (30%). One third (31%) indicated they had received training in one or more therapy(ies) and 65% would be "extremely" or "quite" interested in learning more.

Influence of carotid denervation on the body-core temperature and metabolic responses to changes in ambient temperature during normoxemia and acute hypoxemia in guinea pigs during postnatal maturation.

Acute hypoxemia produces a decrease in body-core temperature (Tbc) in guinea pigs during postnatal maturation, although the factors mediating the response remain unknown. Experiments were therefore carried out to test the hypothesis that the carotid chemoreceptors and (or) baroreceptors mediate the decrease in Tbc during acute hypoxemia. Twelve guinea pigs, six carotid intact and six carotid denervated, were studied in a metabolic chamber to determine the influence of carotid denervation on the Tbc and metabolic (i.e., oxygen consumption) responses to changes in ambient temperature during normoxemia and during acute hypoxemia at 2, 3, and 4 weeks of age. Carotid denervation accentuated the decrease in Tbc in response to a decrease in ambient temperature during normoxemia at 2 and 3 weeks of age but not at 4 weeks of age without altering the metabolic response. This suggests that carotid denervation disrupted heat conservation mechanisms rather than heat production mechanisms in an age-specific manner. Furthermore, carotid denervation accentuated the decrease in Tbc and oxygen consumption in response to acute hypoxemia at all ages studied. This provides evidence that the carotid chemoreceptors and (or) baroreceptors do not mediate the decrease in Tbc that occurs in response to acute hypoxemia in guinea pigs during postnatal maturation.

Influence of pregnancy on the febrile response to intracerebroventricular administration of PGE1 in rats.

Rats have an attenuated or absent febrile response to exogenous pyrogen (e.g., bacterial endotoxin) and endogenous pyrogen (e.g., interleukin-1 beta) near term of pregnancy. The present experiments have been carried out on 19 nonpregnant and 18 time-bred pregnant Long-Evans rats to investigate the febrile response to intracerebroventricular (ICV) administration of prostaglandin E1 (PGE1). Each rat was anesthetized, a biotelemetry device was placed in the peritoneal cavity for measurement of body core temperature (Tbc), and guide cannulas were placed above the lateral cerebral ventricles for ICV injection of PGE1. At least 6 days were allowed to lapse between surgery and the experiments. ICV injection of 0.2 micrograms PGE1 produced significant increases in Tbc in both nonpregnant and pregnant animals (day 19 of gestation). The increase in Tbc as well as the fever index, however, were significantly attenuated in the pregnant compared with the nonpregnant rats. Vehicle had no effect on Tbc or fever index in either group of animals. The attenuated febrile response to PGE1 in the pregnant rats may have resulted from a pregnancy-related activation of endogenous antipyretics and/or impaired thermoregulatory effector mechanisms.

Perioperative nursing care of patients with craniofacial injuries.

Craniofacial injuries are the result of deceleration, blunt, or penetrating trauma. Depending on the mechanism of injury, craniofacial fractures can be minor and go undetected, or they can produce devastating facial deformities. With the advent of intermaxillary fixation devices, surgeons can manipulate facial bone structures and repair soft tissue damage in the majority of patients with craniofacial trauma injuries. Most patients experience optimal results from their craniofacial surgical procedures and return to normal lives after surgery.

Inhibition of protein kinase A-induced glucagon synthesis and secretion by glucose.

The control of glucagon biosynthesis and secretion in the pancreatic islet was examined in response to protein kinase A stimulation at various glucose concentrations. Forskolin plus 3-isobutyl 1-methylxanthine (IBMX) stimulated both glucagon synthesis and secretion at a glucose concentration equivalent to hypoglycemia (0.5 g/L, P<.001), but not at higher glucose concentrations (1.0, 2.0, and 4.0 g/L, P>.05). Destruction of B cells with streptozotocin or inhibition of glycolysis with mannoheptulose did not reverse the inhibitory action of high glucose (4.0 g/L) on the response of glucagon to forskolin plus IBMX. In contrast, citrate but not EGTA treatment permitted forskolin plus IBMX to stimulate glucagon synthesis and secretion (P<.05 and P<.001, respectively) in the presence of high glucose. We conclude that citrate can block the inhibitory action of glucose on the response of A cells to the protein kinase A pathway, possibly through its effects on an intracellular metabolic pathway.

Role of glutamate in regulating hypothalamic proglucagon-derived peptide secretion in vitro.

We have previously demonstrated expression of the proglucagon gene and synthesis and secretion of the proglucagon-derived peptides (PGDPs) in the fetal rat hypothalamus. The excitatory amino acid glutamate has been found to be a key regulator of hypothalamic neuroendocrine hormone secretion. Therefore, the effects of glutamate on hypothalamic PGDP secretion and synthesis were examined in the present study, using the hypothalamic culture model. Glutamate (10 microM) significantly stimulated PGDP secretion (P < 0.01), but had no effect on the total PGDP content of the cultures over 24 hr of incubation. Similarly, the metabotropic/ionotropic glutamate receptor agonist, quisqualic acid (10 microM) stimulated PGDP secretion only ( P < 0.05). In contrast, the ionotropic glutamate receptor agonist, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA; 10 microM) and antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 10 microM), had no effects on either secretion or content of the hypothalamic PGDPs. These findings suggest that excitatory amino acids, and glutamate in particular, regulate secretion but not synthesis of the PGDPs in the hypothalamus.

Control of proglucagon-derived peptide synthesis and secretion in fetal rat hypothalamus.

The hypothalamus has the highest concentration of proglucagon-derived peptides (Pgdp's) in the brain, however, the control of the synthesis and secretion of these peptides is not understood. The goal of our studies was to examine in detail the regulation of synthesis and secretion of Pgdp's in the hypothalamus. Hypothalamic cultures were prepared from fetal rats on day 19-21 of gestation and Pgdp's in media and cells were determined by radioimmunoassay after treatment with test agents. Dibutyryl cyclic AMP or forskolin, activators of protein kinase A, markedly stimulated both Pgdp synthesis (by 5-fold) and secretion (by 10-fold) after 24 h of treatment (p < 0.05). The effects of protein kinase A stimulation on Pgdp's in the hypothalamus were greater than seen in our previous studies with the Pgdp-producing pancreatic A and intestinal L cells. Therefore there are tissue-specific differences with regard to the magnitude of the response of Pgdp's to protein kinase A stimulation. Consistent with an involvement of protein kinase A in hypothalamic Pgdp synthesis and secretion, somatostatin-14, an inhibitor of protein kinase A, was found to inhibit Pgdp synthesis and secretion in a dose-dependent fashion (p < 0.05). Phorbol myristate acetate (PMA), a stimulator of protein kinase C, did not significantly affect the synthesis or secretion of Pgdp's at 6 h, but significantly stimulated Pgdp secretion after 24 h (p < 0.05). The inactive phorbol ester, phorbol triacetate was without effect on Pgdp synthesis or secretion after 24 h of incubation (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Anthocyanin Preparations as Colorants on Hygroscopicity of Dry-Pack Foods.

The equilibrium relative humidity isotherm of a cherry beverage base and a strawberry gelatin dessert mix colored with anthocyanins from grape skins, cranberries and roselle was evaluated versus a Red No. 2 control. As well, the water vapor transmission rate of the packaging material was evaluated to evaluate probable shelf-life. Results indicated that physical parameters, such as hygroscopicity, must be considered in estimating effects of the use of natural colorants in foods as well as the color and chemical stability normally investigated.