Effect of banana on cold stress test & peak expiratory flow rate in healthy volunteers.

The effect of banana on cold stress induced hypertension, peak expiratory flow rate and plasma ACE activity in healthy human volunteers was tested. Systolic blood pressure (P < 0.005), diastolic blood pressure (P < 0.025) and mean arterial blood pressure (P < 0.005) were significantly decreased during cold stress after banana treatment compared to controls subjected to cold stress. There was no significant changes in heart rate and peak expiratory flow rate but only significant decrease in plasma ACE activity after banana treatment. Banana decreased the rise of systolic blood pressure and diastolic blood pressure in healthy volunteers subjected to cold stress test without much effect on heart rate and peak expiratory flow rate.

Effect of chloride and diamide on angiotensin converting enzyme from sheep testis and epididymis.

Effect of chloride and diamide on testicular and epididymal angiotensin converting enzyme (ACE) activity was investigated using Hip-His-Leu as substrate in sheep. The chloride ions functioned as ACE activators, however, there was no linear correlation between the two. The optimum chloride concentrations were 500 mM for epididymal ACE and 900-1100 mM for testicular ACE. Further, optimum chloride concentration increased ACE activity of testis and epididymis 25.40- folds and 12.84- folds respectively of the activities at physiological chloride concentration. The differences found in the effect of chloride on testicular and epididymal ACE activity suggest dissimilar three dimensional structure of ACE in these tissues. Increased testicular and epididymal ACE activity on diamide pretreatment indicates that tissue oxidation may affect ACE activity.

Inhibition of angiotensin converting enzyme from sheep tissues by captopril, lisinopril and enalapril.

Inhibition of angiotensin converting enzyme(EC 3.4,15.1, ACE) in presence of captopril, lisinopril and enalapril were investigated in kidney, lung and serum of sheep using Hip-His-Leu(HHL) as substrate. The activity in kidney, lung and serum was inhibited at HHL concentration above 5 mM. The inhibitory constants (IC50) ranged between 5.6 nM for serum ACE with lisinopril and 70000 nM for renal ACE with enalapril while Ki ranged from 1.0 nM for serum ACE with lisinopril to 12000 nM for kidney ACE with enalapril. Differences in inhibition observed in different tissues suggest that the inhibitors may block function(s) of ACE to varying degrees in each tissue.

A simple technique for improving chromosome spreads from clumped metaphases.

A method has been described by which clumped metaphases either due to inadequate hypotonic KCl treatment or prolonged storage at 4 degrees C can be rescued. The cell pellet obtained from cell suspension following centrifugation was resuspended in freshly prepared Carnoy's fixative (1:3, acetic acid: methanol) at room temperature by vortexing. Twenty microliters of Triton X-100 at a concentration of 0.5% was added drop by drop while vortexing. Three changes with fixative containing 0.5% Triton X-100 were optimal for obtaining good metaphase spreads with complete removal of the cytoplasmic background. The advantage of this technique is that important patients' samples having clumped metaphases otherwise not useful for G-banding can be rescued and karyotyped by this method.

Membrane instability in respiring mitochondria: role of phosphate.

Metabolically-induced (spontaneous) high amplitude swelling of mitochondria has been shown to be due to a serial disruption of the mitochondrial membranes [D. Sambasivarao & V. Sitaramam (1985), Biochim Biophys Acta, 806, 195-209]. Phosphate- and arsenate-induced swelling was investigated in mitochondria to evaluate the role of phosphate transport in the instability created in the mitochondrial membranes. Phosphate-induced swelling in respiring mitochondria was similar to spontaneous swelling. Both represent essentially colloidal swelling due to the variable porosity induced in the inner membrane to polyols by respiration. Swelling of non-respiring mitochondria at high ammonium phosphate concentrations was, on the other hand, primarily due to high permeability to phosphate. This membrane instability created by phosphate transport in the surrounding lipid involves neither the endogenous nor the exogenous Ca2+.

Pulmonary function status of shopkeepers of Ahmedabad exposed to autoexhaust pollutants.

The study deals with evaluation of pulmonary function status (VC, FEV1% and FEF25-75%) in Ahmedabad shopkeepers stationed near different traffic junctions and relating them with the levels of oxides of nitrogen (NOx) near these junctions categorised as Heavy, Medium and Low polluted area junctions. The pulmonary function test (PFT) values of heavy polluted and medium polluted area shopkeepers is compared with low polluted area shopkeepers. The influence of smoking habits and duration of exposure over PFT values was seen. The prevalence of airway obstruction in shopkeepers was compared with USA population. The results indicated significant impairment in FEV1% and FEF25-75% value in high polluted area shopkeepers where NOx level is much higher than TLV value. In medium polluted area, where NOx level is slightly higher than TLV value, shopkeepers demonstrated significant impairment in FEF25-75%. Smoking is found to have an additive effect. A linear increase in the prevalence of pulmonary impairment with increasing duration of exposure was evidenced. Shopkeepers exhibited higher prevalence of impairment in both smokers and non-smokers than USA population attributing it to the effect of autoexhaust pollutants. This study also denoted that FEF25-75% is an early indicator of obstruction in smaller airways which is the primary site of deposition of inhaled pollutants.

Pulmonary function studies in 15 to 18 years age workers exposed to dust in industry.

Pulmonary function tests (VC, FEV1% and FEF25-75%) were evaluated in 15 to 18 years age workers employed in slate pencil industry exposed to silica dust, in wool carpet industry exposed to wool dust and in diamond cutting and polishing exposed to carbon dust. These values were compared with the values obtained in clinically healthy non-smokers of the same age group. The results revealed significant impairment of VC in diamond workers, and FEF25-75% in slate pencil workers. When the values were observed according to smoking habits in diamond workers, VC, FEV1 and FEF25-75% were all significantly reduced in smokers whereas in non-smokers only VC was lowered significantly. Among slate pencil workers FEF25-75% was significantly reduced in both smokers and non-smokers. Wool dust exposed workers showed reduced values than normal subjects. The detailed results including the prevalence of various pulmonary impairments were presented.

Pulmonary function studies in Gujarati subjects.

In this study a multiple regression equation for prediction of ventilatory pulmonary function tests (FVC, FEV1%, FEF25-75% and PEFR) is developed in average healthy non-smoker male and female Gujarati subjects. The average adult female values showed a reduction varying from 21.0 to 29.0% compared to adult male subjects. There is a deviation of the present study values from other studies in Indian subjects and values from European studies are higher than the present values. This study demonstrated that the present regression equation is the most ideal and appropriate for prediction of pulmonary function values in Gujarati subjects either for assessing physical fitness in normal subjects or for determining the pattern of ventilatory impairment in respiratory disease patients. The pulmonary function values assessed by substituting the average age, height and weight of females in male regression equation revealed lower values in females ranging from 14.0 to 19.0% attributable only due to difference in sex.

Oxidative phosphorylation in rat liver mitochondria: influence of physical parameters.

Effects of pH, temperature, ionic strength and osmotic pressure on various respiratory states and indices of oxidative phosphorylation in well coupled rat liver mitochondria have been studied. It appears that temperature and osmotic pressure are the most important physical variables, whereas ionic strength and pH were devoid of any significant influence on oxidative phosphorylation. Thus any model for oxidative phosphorylation must critically account for the differential osmotic sensitivity of respiration as well as the curious fact that ADP/O ratio increases as temperature decreases.