Effect of pH on metabolic and cardiorespiratory responses during progressive exercise

Six healthy male subjects performed three exercise tests in which the power output was increased by 100 kpm/min each minute until exhaustion. The studies were carried out after oral administration of CaCO3 (control), NH4Cl (metabolic acidosis), and NaHCO3 (metabolic alkalosis). Ventilation (VE), O2 intake (VO2), and CO2 output (VCO2) were monitored continuously. Arterialized-venous blood samples were drawn at specific times and analyzed for pH, PCO2, and lactate concentration. Resting pH (mean +/- SE) was lowest in acidosis (7.29 +/- 0.01) and highest in alkalosis (7.46 +/- 0.02). A lower peak power output (kpm/min) was achieved in acidosis (1,717 +/- 95) compared with control (1,867 +/- 120) alkalosis (1,867 +/- 125). Submaximal VO2 and VCO2 were similar, but peak VO2 and VCO2 were lower in acidosis. Plasma lactate concentration was lower at rest and during exercise in acidosis. Although lactate accumulation was reduced in acidosis, increases in hydrogen ion concentration were similar in the three conditions. We conclude that acid-base changes influence the maximum power output that may be sustained in incremental dynamic exercise and modify plasma lactate appearance, but have little effect on hydrogen ion appearance in plasma.     

Effect of dorsolateral pontine lesions on diaphragmatic activity during REMS

Muscle atonia is a feature of normal rapid-eye-movement sleep (REMS). The suppression of accessory respiratory muscle activity has been investigated and a role for sleep-disordered breathing hypothesized, but the suppression of diaphragmatic activity has rarely been considered. We hypothesized that the activity of the diaphragm was suppressed by an area of the dorsolateral pons during REMS. Lesions in this region have previously been shown to abolish the atonia of REMS. The diaphragmatic electromyogram (EMG) activity was analyzed in five naturally sleeping cats before and after pontine lesions leading to REMS without atonia. Although respiratory timing parameters were not altered by the lesion, the inspiratory rate of rise was significantly increased in all cats, and the brief pauses (40-100 ms) in the diaphragmatic EMG normally seen in REMS were virtually abolished. We conclude that the dorsolateral pons has a role in suppressing diaphragmatic activation during REMS. This suppression affects the average rate of rise of diaphragmatic activity and also leads to brief intermittent complete cessation of ongoing muscle activity. These decrements in diaphragm activity could jeopardize ventilation during REMS.     

Effect of arsenic on some physiological parameters in bean plants

The objective of the study was to investigate the effect of different arsenic concentrations on some physiological parameters of bean (Phaseolus vulgaris L.) cultivars Plovdiv 10 and Prelom in the early growth phases. Seedlings, grown in sand with Hoagland-Arnon nutrient solution in a climatic box, were treated with 0, 2, 5 mg(As) dm^–3 as Na₃AsO₄ (pH 5.5). After 5 d of As treatment, the changes in leaf gas-exchange, water potential, chlorophyll and protein contents, peroxidase activity and lipid peroxidation in roots were recorded. Physiological analysis showed a minor negative effect of arsenic at concentration 2 mg(As) dm^–3, but at the higher dosage of 5 mg(As) dm^–3 growth, leaf gas-exchange, water potential, protein content and biomass accumulation were reduced in both cultivars. The peroxidase activity and lipid peroxidation increased considerably at 5 mg(As) dm^–3, which is a typical reaction of the plants to a presence of oxidative stress.     

The effect of neuroleptanalgesia on some cardiorespiratory variables in the rabbit

A technique of neuroleptanalgesia during which rabbits breathed spontaneously for as long as 6 h without any outward sign of stress and with full recovery within 12 h is described. The method involved the constant infusion of a solution comprising fentanyl (0.05 mg/ml) and droperidol (0.13 mg/ml) in 5% dextrose following an intramuscular dose of fentanyl and droperidol. Hourly measurements of blood gases, lung mechanics, mean arterial blood pressure and heart rate were made to assess changes in ventilation and in these physiological parameters for the length of the study. The animals' tracheas were intubated under direct vision with an uncuffed tube. The animals breathed spontaneously and their cardiovascular and respiratory systems were stable throughout the entire monitoring period. There was no statistical difference between the values for all the parameters measured (P less than 0.1). A two-way analysis of variance statistical test was applied to all the measurements.     

Effect of hexachlorobenzene on some male reproductive parameters in Meriones unguiculatus

Organochlorine pesticides are known to cause disturbances in many physiological functions. The effects of in vivo administered hexachlorobenzene (HCB) on the male testicular function were studied in Meriones unguiculatus. Three groups of sexually mature meriones were orally exposed to 1.6, 4, and 16 mg/kg of body weight in olive oil for 30 days. Morphological and morphometrical estimations were applied to quantify some structural constituents of the testes. Testicular weight was significantly decreased in all treated groups, while no change was noted in seminal vesicle weight. A decrease in the spermatozoid content of the seminiferous tube was noted and appeared correlated with a modification of the process of spermatogenesis. Spermatic activity in HCB-treated animals testes decreased significantly, particularly in the group treated with the higher dose (60+/-3.16% vs. 88+/-4.89% in controls). Plasma testosterone levels were decreased significantly in the groups treated with 4 and 16 mg[HCB]/kg BW (0.48+/-0.08 ng/ml and 0.54+/-0.07 ng/ml) comparatively to controls (1.08+/-0.1 ng/ml) p<0.01.     

Influence of respiratory support on respiration parameters

The influence of three types of respiratory support on the respiratory values in wakeful healthy individuals was studied. Specific changes in the pattern of volumetric and temporal parameters were established for each type of respiratory support. One response to all types of respiratory support was hyperventilation, though of different degrees, and hypocapnia as a consequence. These changes are not connected with the metabolic requirements and are apparently a result of interaction between the mechanisms of automatic and voluntary regulation of respiratory movements.     

Effect of the body antiorthostatic posture on various circulation and respiration parameters in anesthetised cats

In anaesthetised cats, antiorthostatic posture of the body with an inclination angle of 30 degrees increased pressure in the vena cava superior and in jugular vein. The rest of the cardio-respiratory parameters were changed insignificantly. Physical and physiological mechanisms of the blood regional redistribution in alteration of the body gravitation orientation, are discussed.     

Effect of selenium supplementation on some blood biochemical parameters in male rats

The long-term effect of selenium supplementation on blood glutathione peroxidase (GSH-Px) activity and plasma TBARS’ production (as an index of peroxidation) was evaluated in 15-mo-old male rats fed a diet supplemented with 0.25 or 0.50 ppm selenium, for 12 mo. A group of nonsupplemented age-matched rats was the control. In addition, triglycerides, phospholipids, total and free cholesterol, HDL-cholesterol, and HDL-phospholipid levels were measured in plasma. Plasma testosterone levels were also determined in order to control the aging process in these animals. The GSH-Px activity and the peroxidation level were unchanged in all the groups. However, concerning the lipid parameters, a decrease in triglycerides concentration was observed in both treated groups (p<0.05). Therefore, in these experimental conditions, despite no observed changes in parameters related to lipid peroxidation, selenium seems to be involved with triglycerides metabolism, eventually improving the triglycerides status of aged animals.     

康复护理对面瘫患者的影响

目的探讨面瘫患者实施康复护理的效果。方法选择2013年1月~2015年12月我院神经科收治的面瘫患者80例为研究对象,随机分为对照组和观察组各40例,对照组给予常规护理,观察组在常规护理基础上实施康复护理,观察比较两组患者的治疗效果。结果观察组临床总有效率明显高于对照组,差异有统计学意义(P0.05)。结论面瘫患者实施康复护理可提高临床效果,促进面神经的恢复,值得临床应用。     

Effect of pedal rate on diurnal variations in cardiorespiratory variables

Recently, it was observed that the freely chosen pedal rate of elite cyclists was significantly lower at 06:00 than at 18:00 h, and that ankle kinematics during cycling exhibits diurnal variation. The modification of the pedaling technique and pedal rate observed throughout the day could be brought about to limit the effect of diurnal variation on physiological variables. Imposing a pedal rate should limit the subject's possibility of adaptation and clarify the influence of time of day on physiological variables. The purpose of this study was to determine whether diurnal variation in cardiorespiratory variables depends on pedal rate. Ten male cyclists performed a submaximal 15 min exercise on a cycle ergometer (50% W_max). Five test sessions were performed at 06:00, 10:00, 14:00, 18:00, and 22:00 h. The exercise bout was divided into three equivalent 5 min periods during which different pedal rates were imposed (70 rev · min^-1, 90 rev · min^-1 and 120 rev · min^-1). No significant diurnal variation was observed in heart rate and oxygen consumption, whatever the pedal rate. A significant diurnal variation was observed in minute ventilation (p=0.01). In addition, the amplitude of the diurnal variation in minute ventilation depended on pedal rate: the higher the pedal rate, the greater the amplitude of its diurnal variation (p=0.03). The increase of minute ventilation throughout the day is mainly due to variation in breath frequency (p=0.01)—the diurnal variation of tidal volume (all pedal rate conditions taken together) being non-significant—but the effect of pedal rate×time of day interaction on minute ventilation specific to the higher pedal rate conditions (p=0.03) can only be explained by the increase of tidal volume throughout the day. Even though an influence of pedal rate on diurnal rhythms in overall physiological variables was not also evidenced, high pedal rate should have been imposed when diurnal variations of physiological variables in cycling were studied.     

老年帕金森病患者康复护理的效果分析

目的探讨老年帕金森病患者康复护理的效果。方法选取我科老年帕金森病患者100例,按随机表法分为观察组和对照组,观察组给予康复护理,对照组给予常规护理,比较两组患者治疗前后日常生活能力及帕金森病症状评分量表(UPDRS)评分情况。结果护理干预后,两组患者的UPDRSⅡ、Ⅲ评分均低于干预前(均P0.05),且观察组显著优于对照组(P0.05)。结论老年帕金森病患者实施康复护理可提高临床疗效,提高患者日常生活能力,增强战胜疾病的信心。     

Effect of alpha2 macroglobulin on some kinetic parameters of trypsin.

1. Complex formation of trypsin with alpha2 macroglobulin results in marked changes of the Michaelis-Menten constant, pH optimum and sensitivity to ionic strength in a system using N-carbobenzoxy-glycylglycyl-L-arginine-2-naphthylamide as substrate. 2. In contrasts to the inhibition (50%) observed when alpha2 macroglobulin-bound trypsin is assayed under conditions optimal for the free enzyme, there is minimal reduction of activity when determinations are performed at a substrate concentration and pH optimal for the bound enzyme. 3. The changes in substrate concentration and ionic environment required for maximum activity of alpha2 macroglobulin-bound trypsin are similar to those observed with enzymes embedded in polyelectrolyte matrices and may reflect alterations in the microenvironment of the enzyme resulting from conformational changes of the macromolecule during interaction with trypsin. 4. Enzymatic activity of trypsin towards casein is greatly reduced by alpha2 macroglobulin, even under assay conditions optimal for the bound enzyme, confirming previous findings that access to the active center for high-molecular weight substrates is sterically hindered by alpha2 macroglobulin.     

Effect of lung inflation on diaphragmatic shortening

The effect of lung inflation on chest wall mechanics was studied in 11 vagotomized pentobarbital sodium-anesthetized dogs. Diaphragmatic shortening (percent change from initial length at functional residual capacity, %LFRC) and transdiaphragmatic pressure swings (delta Pdi) were compared with control values over a range of positive-pressure breathing that produced a maximum increase in lung volume to 40% of inspiratory capacity. There was no change in the electromyogram of the diaphragm or parasternal intercostals during positive-pressure breathing. delta Pdi and tidal volume (VT) fell to 52 +/- 3.3 and 42.5 +/- 5% (SE) of control. This was associated with a reduction in the initial resting length of 13 +/- 1.9 and 21 +/- 2.2%LFRC (SE) in the costal and crural diaphragms, respectively. Tidal diaphragmatic shortening, however, decreased to 66 +/- 7 and 57 +/- 7 and the mean velocity decreased to 78 +/- 10 and 63 +/- 8% (SE) of control for the costal and crural diaphragms, respectively. We conclude that the reduction in diaphragmatic shortening is the main determinant of the reduced delta Pdi and VT during lung inflation and relate this to what is currently known about diaphragmatic contractile properties.