Nitric oxide-mediated neurotransmission is attenuated in the anococcygeus muscle from diabetic rats

Summary The effect of STZ-induced diabetes of 8-weeks duration was examined on nitric oxide-mediated neurotransmission in the rat anococcygeus muscle. In the presence of noradrenergic blockade and raised tissue tone, relaxant responses to nerve stimulation (0.5–5 Hz, for 10 s), sodium nitroprusside (5 and 10 nmol/l) and nitric oxide (1 and 3 mol/l) were significantly reduced in anococcygeus muscles from diabetic rats compared to responses from control rats (p <0.05). In contrast, relaxations to papaverine (3 and 10 mol/l were not reduced in tissues from diabetic rats. The nitric oxide synthesis inhibitor NOLA (100 mol/l) abolished relaxant responses to nerve stimulation but had no effect on responses to any of the relaxant agents used. Exposure to NOLA at 10 mol/l reduced stimulation-induced relaxations; this reduction was significantly greater in tissues from the diabetic group than from the control group (p <0.05), probably as a consequence of the smaller relaxant responses in muscles from diabetic rats. Contractile responses to nerve stimulation (1–10 Hz, for 10 s), but not noradrenaline (0.03–30 mol/l), were significantly greater in anococcygeus muscles from diabetic rats than from control rats (p <0.05). NOLA (100 mol/l) significantly enhanced stimulation-induced contractions (p <0.05), however the enhancement was significantly less in tissues from diabetic rats (p <0.05). The results suggest that STZ-induced diabetes impairs smooth muscle reactivity to nitric oxide in the rat anococcygeus muscle.Abbreviations STZ Streptozotocin - NOLA N^G-nitro-l-arginine - NANC nonadrenergic noncholinergic - ANOVA analysis of variance     

Daily variability in resting levels of cardiovascular variables in normal subjects and those with homozygous sickle cell disease

Measurements were made of cardiovascular variables and oral temperature in 16 male subjects with homozygous sickle cell disease (SS) and in 17 matched controls (AA) at 10.00 a.m., 1.00 p.m. and 4.00 p.m. All subjects were in a rested state throughout. At 10.00 a.m., mean arterial pressure was lower, while heart rate, total forearm blood flow and cutaneous red cell flux in the forearm were higher in SS than AA. Vascular resistance in total forearm and forearm skin, calculated by dividing arterial pressure by blood flow or red cell flux, were lower in SS but hand cutaneous red cell flux and vascular resistance were not significantly different in SS and AA. In both SS and AA, there were parallel increases over the three sessions, in mean arterial pressure (by 12 and 10%, respectively) forearm vascular resistance (by 17 and 27%) and hand cutaneous vascular resistance and hand cutaneous resistance (by 240 and 350%) whereas forearm blood flow and hand cutaneous red cell flux fell. By contrast, forearm cutaneous resistance showed no change during the day in SS, but increased progressively in AA (by 75%). These results indicate that, during the day, there is progressive vasoconstriction in forearm muscle and hand skin in SS and AA and also in forearm skin of AA that contributes to a progressive rise in the resting level of mean arterial pressure. We suggest this daily variability should be considered in studies of cardiovascular function: within a given study they should be performed at the same time of day.     

Development and preliminary validation of an instrument to assess quality of sitting of children with neuromotor dysfunction

The development of a clinical instrument to assess static and dynamic postural control in sitting in children with neuromotor dysfunction is described. A review of the literature has supported the need for objective assessment tools for measuring various aspects of functioning with this population. In this paper the conceptual basis and preliminary validation study results of a new instrument, the Sitting Assessment for Children with Neuromotor Dysfunction (SACND) are presented. Initial results show the SACND to have good inter-rater reliability, and discriminant validity. Construct validity testing suggest the SACND shows promise for use by clinicians and researchers. Further research is needed to assess the SACND's test-retest reliability, the major underlying test constructs, and the effects of intervention on test scores.     

Pesticide exposure in a farming village in Venezuela--a developing country

This study was designed and performed by the Universidad de Carabobo, Centro de Investigaciones Toxicológicas, Venezuela, and the University of Cincinnati Department of Environmental Health. The authors tested methodology and analyzed preliminary data on demographics, pesticide use, health, environment, and lifestyles in a farming community in Venezuela (population = 386; sample size = 81) to determine if pesticide misuse might have been contributing to public health problems. Questionnaire and geographic information were collected. There were statistically significant incidences of pesticide-related symptoms (p < .01) in farmers versus nonfarmers (odds ratio = 5.7; 95% confidence interval = 2.9, 18.8). In addition, in one area there was a cluster of farmers who experienced symptoms that appeared to be the result of foul air and proximity to farms where there was pesticide use. The results of the study indicated that this public health problem may have been associated with pesticide misuse; however, additional studies are needed to corroborate the findings.     

The views and outcomes of consenting and non-consenting patients receiving ECT

BACKGROUND: Current mental health legislation in the UK makes provision for the use of certain treatments in severely ill patients who are unable, or unwilling, to give informed consent. Under the terms of this legislation, electroconvulsive therapy (ECT) may be used, usually to treat severely depressed patients. A number of organizations have challenged this practice, stating that ECT should only be given with fully informed consent: it has been implied that patients receiving compulsory ECT (given without the patient's consent, under the terms of mental health legislation) find the treatment damaging and unhelpful. METHODS: A series of 150 patients receiving ECT in Aberdeen was studied. A proportion of the series (approximately 7%) received compulsory ECT. The views and treatment outcomes of compulsory patients were compared with those of patients giving informed consent for treatment. RESULTS: More than 80% of patients in both consenting and compulsory groups considered ECT to have helped them. Clinical outcome did not differ between the groups. Patients' views showed marked concordance with independent medical evaluation of outcome. CONCLUSIONS: Outcome following ECT in non-consenting patients is equivalent to that seen in consenting patients whether rated by the patients themselves or by clinicians. Overall outcome is good, with more than 80% of patients benefiting from treatment. A ban on compulsory ECT would deny the access of seriously ill patients to an effective and acceptable treatment.     

A behavioral approach to identifying sources of happiness and unhappiness among individuals with profound multiple disabilities

This investigation evaluated a behavioral means of identifying sources of happiness and unhappiness among individuals with profound multiple disabilities. Indices of happiness and unhappiness were defined, and a corresponding observation system was developed and implemented with five students in an adult education classroom. Each student was observed while participating in two separate classroom activities. Results indicated the definitions and the observation system reliably identified different frequencies of happiness and/or unhappiness indices for each student across separate activities. Results are discussed regarding routine use of the observation system to evaluate classroom activities for effects on student happiness as a measure of quality of life. Future research needs are discussed in terms of determining means to alter certain classroom procedures that are accompanied by indices of student unhappiness.     

The hereditary spastic paraplegias

The hereditary spastic paraplegias are a complex group of neurodegenerative conditions which are characterised by slowly progressive lower limb spasticity. This article describes the main clinical features of pure and complicated hereditary spastic paraplegias and summarises recent advances in our understanding of the molecular genetics of these conditions. Received: 2 June 1999 Accepted: 7 August 1999     

Clonal mixing, clonal restriction, and specification of cell types in the developing rat olfactory bulb

To understand the clonal relationship of various olfactory bulb (OB) cell types, OB progenitor cells were infected at embryonic day (E) 14, E15, and E17 with retroviral libraries encoding alkaline phosphatase or beta-galactosidase. After survival to postnatal day 10-15, sibling relationships were identified by polymerase chain reaction DNA amplification of distinct sequences in the retroviral constructs. Within the OB, clonal progeny dispersed widely in all directions. In sharp contrast, however, clonal dispersion between the OB and neocortex was not observed, although occasional clonal dispersion between the OB and pyriform and hippocampal regions could not be excluded. Most clones (84%) contained a single cell type, especially after E17 injections, suggesting the existence of either restricted precursors, or multipotential progenitors instructed by a restricted cellular environment. Mixed OB clones (16%) contained multiple cell types in the OB, or occasionally glial or neuronal cells outside the OB, demonstrating the existence of multipotential OB progenitors, likely at a stage before formation of the olfactory rostral migratory stream. Surprisingly, OB glial cells were not labeled, suggesting distinct lineages or perhaps distinct migratory paths for glia and neurons into the OB. A hierarchical cell lineage is proposed that involves a multipotential progenitor that gives rise to potentially more limited progenitors.