NMDA-receptor blockers but not NBQX,an AMPA-receptor antagonist,inhibit spreading depression in the rat brain

The effect of different glutamate-receptor antagonists on the induction of cortical spreading depression of Leao and of cortical anoxic membrane depolarization were investigated in the anaesthetized rat. Spreading depression (SD), elicited by mechanical stimulation of the cortical surface, was inhibited by the non-competitive N-methyl-d -aspartate (NMDA)-receptor blocker, (±)-5-methyl-10,11-dihydro-SH-dibenzo(a, d)-cyclo-hepten-5,10-imine maleate (dizocilpine or MK-801), (0. 30 μmol kg^-1 (0. 10 mg kg ^-1)), and the competitive NMDA-receptor antagonists; cis-4-phosphonomethyl-2-piperidine carboxylate (CGS 19755), (3.36 μmol kg^-1 (0.75 mg kg^-1)), d -(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid (CGP 40116), (1.20 μmol kg^-1 (0.25 mg kg^-1)) and its carboxylester CGP 43487, (6.30 μmol kg^-1 (1.50 mg kg^-1)). The α-amino-3-hydroxy-5-methyl-4-isoxazolepripriate (AMPA)-receptor blocker, 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F) quinoxaline (NBQX), administered as an intravenous dose of 29.76 and 89.29 μmol kg^-1 (10 & 30 mg kg^-1), which is sufficient to block seizures and protect against ischaemic brain damage, did not inhibit spreading depression. None of the drugs utilized inhibited the anoxic membrane depolarization. The data demonstrate that NMDA-receptor activation is essential for the initiation and propagation of spreading depression, while activation of AMPA-receptors is not obligatory. The observed initiation and propagation of SD, during AMPA-receptor blockade, suggest that activation of voltage-operated ion channels may contribute to release the magnesium block of the NMDA-receptor operated channel and to the initiation of SD.     

The role of spinal cord cyclic AMP in the acoustic startle response in rats

Drugs thought to increase intracellular levels of cAMP were infused intrathecally into the subarachnoid space of the lumbar spinal cord, and the effects on the acoustic startle response in rats were measured. Intrathecal infusions of the cAMP analogs dibutyryl cAMP or 8-bromo cAMP (12.5-100 micrograms) produced marked, dose-dependent increases in startle amplitude compared to the infusion of artificial cerebrospinal fluid (CSF). Local infusions of dibutyryl cAMP at more rostral levels of the spinal cord or brain failed to mimic the excitatory effect seen following lumbar intrathecal infusion. No excitation of startle was seen following intrathecal infusion of cAMP itself, ATP, 5'-AMP, or dibutyryl cGMP. A weak excitation of startle was seen following intrathecal, but not intraventricular, infusion of the water-soluble adenylate cyclase activator forskolin 7-deacetyl-7-O-hemisuccinic acid (forskolin-DHA; 5.0-100 micrograms, in artificial CSF), whereas forskolin itself [0.01-200 micrograms, in dimethyl sulfoxide (DMSO)] was without consistent effect. Finally, intrathecal infusion of the selective phosphodiesterase inhibitor Rolipram (12.5-200 micrograms) produced a marked excitation of startle similar in magnitude to the effects produced by cAMP analogs. The excitatory effects of intrathecally infused dibutyryl cAMP, 8-bromo cAMP, forskolin-DHA, or Rolipram support a functional link between spinal cord cAMP and the acoustic startle reflex. Possible sites of cAMP action on startle are discussed.     

Scimitar syndrome: four new cases examined with CT

Four new cases of scimitar syndrome illustrate the complex derangement of the right lung architecture. Computed tomography (CT) helped in demonstrating the hyparterial relationship of the right bronchus to the pulmonary artery, the course and termination of the scimitar vein, the mediastinal shift, unusual fissures, and abnormal lobation and bronchial distribution. The CT findings confirm that the retrosternal opacity and indistinct right heart border are results of the mediastinal shift. One case had features resembling, but clearly distinguishable from, the horseshoe lung syndrome.     

Dietary intake of 70- to 89-year-old men in eastern and western Finland.

A detailed dietary history interview of 70- to 89-year-old men, 98 from eastern and 129 from western Finland, was obtained as part of a 30-year follow-up survey within the Seven Countries Study. The average energy intake was similar in level, about 2700 kcal, in both areas. The percentage of total energy intake from fat was 39.1% in the west, and 36.5% in the east. The P/S ratio was about the same, 0.27 and 0.29, in eastern and western areas, respectively. The intake of most micronutrients was similar in the two cohorts. Only the intake of vitamins A and C and phosphorus, manganese, copper and zinc was higher in eastern Finland than in western Finland. The nutritional density of the diet of the eastern cohort was slightly higher than that of the western one due to their higher consumption of rye products, vegetables and berries, and also sour milk and fish and fish products. The diet met the general recommendations and was comparable to that of younger age groups.     

Body composition of patients with Alzheimer's disease

Low body weight is frequently reported in patients with Alzheimer's disease. We sought to discover why by comparing the body composition of 28 cognitively normal elders and 23 institutionalized individuals with Alzheimer's disease. Body mass index was calculated from standing height and weight. Percentages of lean body mass, body fat, and body water were derived from bioimpedance measurements of resistance and reactance. Skinfold thickness was measured at seven body sites to estimate regional fat distribution. Variables were analyzed by analysis of variance with subjects grouped by cognitive status within gender. Activity level and age were not significant covariates. Both women and men with Alzheimer's disease weighed less than control subjects. Differences in body composition were more pronounced in women with Alzheimer's disease, who had lower body mass index (22.0 ± 3.0 vs 26.1 ± 5.1), higher percentage of lean body mass (73.8 ± 5.1 vs 66.9 ± 6.5), lower percentage of body fat (26.1 ± 5.1 vs 33.1 ± 6.5), and higher percentage of body water (55.8 ± 5.0 vs 49.3 ± 6.5) compared with control women. Except for lower body weight, the body composition of men with Alzheimer's disease was not significantly different from that of control men. Patients of both sexes with Alzheimer's disease had less truncal body fat compared with controls, which gave them a youthful body habitus. These differences were not accounted for by age, diet, or activity. Our findings indicate that patients with Alzheimer's disease have lower body weight and may require higher energy intake than cognitively normal elders.     

Comparison of anthropometric measures of men with HIV: Asymptomatic, symptomatic, and AIDS

Objective Anthropometric measures were performed to determine differences in estimated fat mass, lean body mass, and body weight among three groups of men infected with human immunodeficiency virus (HIV).

Design This study was cross-sectional.

Setting Local centers of community services and support groups for persons infected with HIV in the province of Quebec, Canada.

Subjects Thirty-seven HIV-positive men were recruited; 11 were asymptomatic (T helper cells [CD4 + count] > 400 cells/mm³), 8 were symptomatic (CD4 + < 400 cells/mm³), and 17 were clinically stable but met the criteria of the Centers for Disease Control and Prevention for acquired immunodeficiency syndrome (AIDS).

Main outcome measures Self-reported usual weight, actual weight, body mass index, midarm circumference, and triceps and subscapular skinfolds were recorded. From those we derived the percentage of body fat, the midarm muscle, and fat areas. Daily energy and protein intakes were determined from a 7-day food record. Clinical signs and symptoms were assessed by a structured questionnaire.

Statistical analyses performed For statistical comparisons, analysis of variance was used, with P < .05 being significant.

Results We found a trend toward a decrease in body weight and in the fat mass indicators as the disease progressed. Lower energy intakes were observed among symptomatic and AIDS groups. The number of nutrition-related clinical signs and symptoms experienced by each individual correlated with the magnitude of weight loss (P < .0004, R = −.69).

Applications The findings suggest that anthropometric measures can be used in routine clinical practice to assess changes in body weight and in estimated fat mass among men infected with HIV. Symptoms and energy intakes should be assessed to identify subjects at high risk of greater weight loss.     

Nasal congestion during the menstrual cycle

Oestrogens have been considered to cause nasal congestion during the menstrual cycle and during pregnancy. The aim of the present study was to evaluate the degree of nasal congestion during the menstrual cycle in healthy women. Nasal peak expiratory flow (nPEF) was measured and subjective nasal stuffiness was scored morning and evening by 27 women for 3 months and by 14 women for 6 months. During the menstrual days, when the serum oestrogen level is lowest, the morning nPEFs were significantly lower compared with the rest of the cycle (P= 0.0012). The difference was most pronounced for the second day of the cycle (P= 0.00034). The correlation between nPEFs and the subjective scores was high (R= 0.98), while the coefficient of variation within the series of three nPEF recordings was low (6.4%). It is concluded that the nasal obstruction experienced during menstruation cannot be explained by increased serum levels of oestrogen.