Pulmonary function changes in asthmatics associated with low-level SO2 and NO2 air pollution, weather, and medicine intake

This paper presents the response in subjects with asthma to gaseous air-pollution levels, weather, and medicine intake as identified by principal-component analysis and neutral network techniques. Pulmonary function measured by respiratory peak-flow rate in nonallergic asthmatics was associated with ambient, low level, air-pollution concentrations of sulphur dioxide and nitrogen dioxide, temperature, relative humidity, and medicine intake. Results from 27 nonallergic asthmatics aged 18–60 years with well-characterized bronchial asthma and regular medical treatment were analyzed from two cities. During an 8-month period, each subject kept a diary table, which included symptoms, lung function (evening peak flow), medicine intake, and tobbaco smoking.
High intake of medicine and high ambient temperatures correspondend to decreased peak flow. The changes in temperature did not occur in situations with low medicine intake. During frost periods, peak-flow values decreased independently of medicine intake and levels of so². During other times, increased levels of so² and no² increased temperature, and increased intake of medicine, and low relative humidity corresponded to synergistically to decreased peak flow at levels above 40μ/m³.     

LH syndrome and brain catecholamine levels after lesions of the nigrostriatal bundle

Lesions of the nigrostriatal bundle (NSB), whose fibers pass through the medial portions of the internal capsule and the immediately adjacent lateral hypothalamus (LH), produced a more severe aphagia, adipsia, and disturbance of water regulation than did lesions of the medial forebrain bundle (MFB). When deprived of food, animals with NSB lesions drank significantly less than controls and animals with MFB lesions. NSB lesions also produced greater decreases in telencephalic content of the catecholamines than MFB lesions, while the reverse was true for serotonin. Water intake during food deprivation was highly correlated with telencephalic catecholamine levels in animals with NSB lesions. Thus, the inability to regulate water intake in the absence of food, one of the characteristic and long lasting effects of the LH syndrome, appears to be due to destruction of the NSB and the consequent decline in telencephalic content of catecholamines.     

Hypotension and thirst in rats after isoproterenol treatment

Drinking induced in rats by systemic isoproterenol treatment is markedly attenuated after bilateral nephrectomy. The present experiments demonstrate that the hypotension produced by iso-proterenol treatment was more profound, and lasted much longer, in nephrectomized rats than in intact animals. When arterial blood pressure was partially elevated by central administration of angiotensin II or carbachol (Experiment 1) or by intraarterial infusion of epinephrine (Experiment 2), drinking behavior was restored in the nephrectomized animals and their water intakes approximated the amounts consumed by intact rats given isoproterenol. In general, an inverted U-shaped curve was found to define the relation between blood pressure and water intake in rats after isoproterenol treatment. Drinking was most probable when mean arterial blood pressures were in the range of 70–85 mm Hg, whereas rats were unlikely to drink when blood pressures were much below or above this range. These findings indicate that isoproterenol-induced thirst is not dependent on a renal dipsogen, and suggest instead that the hypersecretion of renin that occurs in intact rats is simply permissive of drinking behavior by modulating the hypotensive effects of the drug treatment.     

Visual perception in women during the menstrual cycle

Twelve females were tested at four times during the menstrual cycle with a visual detection task and a visual pattern discrimination task. Mood levels and confidence ratings were evaluated for each session. In addition to the behavioral testing, plasma samples were collected and radioimmunoassayed for estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone levels. Visual detection fluctuated significantly during the menstrual cycle with impaired performance occurring at the premenstrual session. In contrast to previous reports, the impaired performance was not related to lowered confidence ratings or to mood levels.     

Fine particulate matter exposure during pregnancy and infancy and incident asthma

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The mechanisms of fast renal compensation

Summary The changes in blood concentration which result in the adjustment of excretion when renal functioning mass is acutely reduced have been investigated by means of paired experiments on isolated dog kidneys. One kidney was perfused with undiluted blood; the other kidney was perfused with blood supplemented with an amount of water and solutes corresponding to the amount retained after the suppression of the contralateral kidney in situ; the response was evaluated from the difference in excretion between the two organs. The results may be summarized as follows: a) the adjustment of the excretion of water, sodium, potassium and urea results from small changes in blood concentration (haematocrit, plasma proteins and solutes), in the absence of specific stimuli of extrarenal origin; b) increased urea concentration is not the major determinant of the readjustment of sodium and water excretion; c) the response is potentiated by high arterial blood pressure; d) if the load of water exceeds the load of sodium, this ion is retained by the kidney even in the presence of an osmotic load of urea; e) the changes in the blood concentrations do not provide an adequate adjustment of the excretion of phosphate; f) increased excretion per nephron results from decreased fractional reabsorption without significant change in glomerular filtration rate.     

Hyperdipsia produced by severing ventral septal fiber systems.

The septum of male hooded rats (N = 59) was completely isolated from the rest of the brain (ISS) or was partially isolated by severing dorsal (DP), ventral (VP), anterior (AP), or posterior (PP) fiber tracts using a knife-cut technique. Daily water intakes and intakes following hypertonic NaCl and polyethylene glycol (PG) injections were measured. The septum totally degenerated for the ISS group and these rats had normal or hypodipsic daily intakes, likewise for intakes following NaCl and PG. Rats of the VP group sustained little septal damage, yet these cuts yielded the highest percentage (55 percent) of hyperdipsic daily drinkers of any group. The daily hyperdipsic rats drank normally in response to NaCl and PG, demonstrating a dissociation between daily drinking and drinking in response to specific thirst stimuli. The results indicate the importance of ventral fiber systems in the production of Septal Hyperdipsia, and support the notion that the septum has multiple effects upon water regulation.     

Serum levels of total IgE in non-allergic children

The purpose of this study was to establish the range of total serum IgE in a healthy population lacking personal and family history of allergy, as well as the influence of genetic factors (family history of allergy), environmental factors (degree of air pollution), age, and sex on the serum IgE levels. Using a commercial enzyme immunoassay (Phadezym IgE Prist) the mean serum level of IgE was determined in 363 non-atopic children from 0 to 12 years of age. The geometric mean of serum IgE increased according to age, indicating a positive correlation between both. Higher mean values of serum IgE were found for children with a family history of allergy, than for children without (27.82 and 14.49 U/ml respectively). The percentage of variation due to age was about 94.5% in children with no family history of allergy. The mean value of serum IgE increased with the degree of air pollution in the living area (15.49 U/ml in non-polluted areas, 20.78 U/ml in very polluted areas). However, the influence of air pollution was smaller than the influence of family history on the mean values of serum IgE. The mean value of serum IgE was not modified by sex.     

Interaction between the septal area and the subfornical organ in the control of water intake induced by thirst-eliciting procedures

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake.