The effects of benzene hexachloride (BHC), an organochlorine pesticide, on cell growth and phosphatase activities were studied in the growing and developing stages of cells of the cellular slime mould Dictyostelium discoideum exposed to BHC (containing alpha-, beta-, delta- and gamma-isomers) at concentrations of > or = 60 micrograms ml-1. A significant increase in acid and alkaline phosphatase activities was recorded in both growing and differentiating Dictyostelium cells treated with different doses (> or = 60 micrograms/ml) of BHC. The cytotoxicity of BHC has been correlated with the stimulation of acid and alkaline phosphatase activities of this organism.

Acid Phosphatase↗

PubMedDate not supplied

Gentamicin-induced alterations in phospholipid metabolism in cultured human proximal tubular cells.

The effects of gentamicin on phospholipid levels and metabolism and the uptake of phosphatidylcholine (PC) adsorbed to low-density lipoprotein (LDL) were investigated in cultured human proximal tubular (PT) cells. Cells incubated with gentamicin (0.3 mM) for one to 21 days had a similar increase in the cell number and protein as compared to control cells. However, the cellular levels of phosphatidylcholine (PC) and sphingomyelin (SM), but not other phospholipids, increased in a time-dependent manner. Incubation of gentamicin (0.3 to 3.0 mM) resulted in a concentration-dependent increase in the cellular levels of PC (50% to 320%) and SM (20% to 40%). Gentamicin stimulated the incorporation of [14C]-acetate into diacylglycerol, PC, and SM in the order of 300%, 66%, and 20%, respectively, but not into lysophosphatidylcholine (LPC). Similarly, gentamicin stimulated the incorporation of [14C]-choline into PC and SM in the order of 300% and 172%, respectively, but not into LPC as compared to control cells. In addition, gentamicin also stimulated the incorporation of [14C]-choline into cytidine diphosphocholine (CDP-choline). However, the endocytosis of [14C]-PC-LDL was lower in cells incubated with gentamicin than in control cells. Thus, exogenously derived PC on LDL does not contribute to the increased cellular levels of PC in PT cells incubated with gentamicin. The activity of cytidine triphosphate (CTP):phosphocholine cytidyltransferase was moderately lower in cells incubated with gentamicin as compared to control. By contrast, the activity of phospholipase A1 and phospholipase C was twofold lower in cells incubated with gentamicin for 21 days as compared to control. Thus, increased incorporation of [14C]-acetate and [14C]-choline into PC in cells incubated with gentamicin may not only be due to increased endogenous synthesis but to decreased catabolism of newly synthesized PC. We conclude that gentamicin impairs the lysosomal catabolism of PC, leading to its accumulation in PT cells. This phenomenon may be an indication of gentamicin-induced nephrotoxicity in man.

Cells, Cultured↗

PubMedDate not supplied

Epidermal growth factor (EGF) replaces estradiol for the initiation of embryo implantation in the hypophysectomized rat.

Several studies have provided evidence that epidermal growth factor (EGF) or transforming growth factor alpha (TGF alpha) mediate some of the physiological effects of estrogen. The object of the present study was to determine whether exogenous EGF could initiate embryo implantation in the rat, a response known to depend upon the action of estrogen in a progesterone-primed uterus. Immunocytochemical examination showed the presence of immunoreactive EGF, TGF alpha and the EGF receptor in luminal glandular epithelium of uteri on days 4,5 and 6 of pregnancy. EGF receptor was also present in the implanting embryo and in decidual cells of the uterine stroma. Attempts to initiate implantation by intravenous injection of murine EGF into ovariectomized or hypophysectomized delayed-implanting rats maintained with progesterone were unsuccessful. Implantation sites were found, however, in 24 of 33 (73 per cent) hypophysectomized progesterone-primed rats given 100 micrograms EGF immediately after intrauterine transfer of blastocysts from hypophysectomized delayed implanting animals. Although EGF is capable of initiating implantation in the delayed implanting rat model it remains to be determined whether this growth factor is responsible for the implantation inducing action of estrogen in vivo.

Animals↗

PubMedDate not supplied

Permanent flank bulge is a consequence of flank incision for radical nephrectomy in one half of patients.

The objective of the study was to determine the incidence and predictors of post operative pain and flank bulging in patients undergoing nephrectomy for a renal tumor through a flank or thoracoabdominal incision. Only one previous retrospective study (1974) has directly addressed this issue in urologic patients. This reported a 3% incidence of flank bulging. This was at variance with our own experience. To determine the incidence of pain and post-operative flank bulge after flank or thoraco-abdominal incision, a cross sectional survey among in 70 patients, who had a nephrectomy for a renal tumor between 1996 and 2000, was assessed by telephone interview. Four surgeons contributed patients to the study. Thirty-four of seventy (49%) patients complained of a flank bulge persisting more than 1 yr after surgery. Durable flank pain was experienced by 24%. This was severe in 3% of patients. Median pain magnitude was 5/10. There was no difference in bulge incidence between surgeons (P = 0.49). Flank bulging occurred more frequently in left sided nephrectomy (P = 0.054) than right. Other parameters including gender, age, and tumor size had no correlation with the rate of either complication. In all patients who described a flank bulge, the deformity was durable; there were no cases of spontaneous resolution. Patients described a significant impact on QOL, particularly in those under 60 yrs. The overall rate of postoperative flank bulging is considerably higher than has been previously reported. This deformity affects quality of life. The observation that almost 50% of patients experience a flank bulge following a flank incision supports the shift towards laparoscopic nephrectomy, and should be incorporated into decision making regarding the optimal surgical approach. This may be particularly relevant in the choice between open partial nephrectomy and laparoscopic radical nephrectomy in a patient with a normal contralateral kidney.

Aged↗

PubMedDate not supplied

Effect of nitric oxide on mortality of mice after whole body hyperthermia.

The objective of this study is to find the role of nitric oxide (NO) in the haemodynamics of mice subjected to heat stress caused by Whole Body Hyperthermia (WBH) treatment. L-arginine (L-arg), a natural substrate for NO synthase (NOS), N-nitro-L-arginine methyl ester (L-NAME), a preferential inhibitor of endothelial NOS, and dexamethasone, a preferential inhibitor of inducible NOS, have been used to study the role of NO in thermal injury caused by WBH treatment. Nitrite in plasma and mortality of Swiss male mice subjected to WBH treatment induced by radiant heat (40 degrees C fo 1 h at 50-55% relative humidity), were monitored in mice pre-treated with either L-NAME, dexamethasone or L-arg. A batch of mice subjected to 24 h fasting prior to WBH treatment was also used to study the above parameters. Injections with 1.5 mg/kg or above of L-NAME just before WBH treatment, induced mortality in mice, with a corresponding drop in plasma nitrite values. L-arg (8 mg/kg) pre-treatment reversed the killing caused by L-NAME in WBH treated mice. L-arg (60 mg/kg) pre-treatment induced mortality in mice subjected to WBH treatment. In the fasted group, a very low dose of L-arg (8 mg/kg) given before WBH treatment led to a significant increase in plasma nitrite levels. In both the normal and fasted groups of mice, 120 mg/kg of L-arg pre-treatment resulted in a sharp increase in plasma nitrite values and subsequent death of mice. The results throw up an important finding, in that the interaction of elevated body temperature, with either a decrease or over production of nitrite oxide, leads to modulation of thermal injury of mice, caused by WBH treatment.

Animals↗

PubMedDate not supplied

Pulmonary function studies in healthy non-smoking men of Calcutta.

Pulmonary function measurements were made in 104 healthy non-smoking men from Calcutta with an age range of 20-59 years. Except for peak expiratory flow rate (PEFR), all the measurements were made with the help of two 9L closed-circuit type expirographs using standard spirometric techniques. PEFR was recorded by two Wright peak flow meters. Prediction formulae were derived on the basis of age and height for all the ventilatory tests except for FEV1%, FET and PEFR. These were predicted from age only. The prediction equation for VC, FVC, FEV1, FEV1%, MVVF and PEFR were reliable, but those for forced expitatory flows and time were not. The FVC and FEV1 values of the present subjects, standardized for age and height, were much lower than those of Americans, Caucasians, Europeans and Canadians but similar to those of Pakistani healthy adults. On comparison with the data reported from other parts of our country, it was revealed that the VC and FEV1 values of the current study, after adjustment of age and height, were much higher than those of southern Indians but comparable with those of north-western Indians.

Adult↗

PubMedDate not supplied

Pulmonary function studies in healthy non-smoking women of Calcutta.

Pulmonary function measurements were made in 230 healthy non-smoking women from Calcutta with an age range of 20-59 years. The tests consisted of vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory volume in one second as a percentage of forced vital capacity (FEV1%), forced expiratory time (FET), maximum voluntary ventilation, uncontrolled frequency (MVVF), forced expiratory flow (FEF200-1200ml), forced mid-expiratory flow (FEF25-75%), forced end-expiratory flow (FEF75-80%) and peak expiratory flow rate (PEFR). Except for PEFR, all the measurements were made with the help of two 9-litre closed-circuit-type expirographs using standard spirometric techniques. PEFR was recorded with the help of two Wright peak flow meters. Prediction formulae were derived on the basis of physical characteristics. Age and height were found to be the significant predictor variables for VC, FVC and FEV1, while only age was significant for FEV1%. The FVC and FEV1 values of the subjects, standardized for age and height, are much lower than those of Americans, Europeans and Jordanians. On comparison with data reported from other parts of India, it was revealed that the VC and FEV1 values of the current study, after adjustment for age and height, were much higher than those of Southern Indians but comparable with those of North-Western Indians.

Adult↗

PubMedDate not supplied

Lung function in Indian twin children: comparison of genetic versus environmental influence.

The relative contributions of genetic and environmental components in the variability of lung function measurements were studied in 54 twin pairs. Thirty pairs of monozygote (MZ) twins and 24 pairs of dizygotic (DZ) twins were examined. All measurements were made with 9-litre closed-circuit-type expirographs using standard spirometric techniques, except for peak expiratory flow rate (PFER) which was recorded with a Wright peak flow meter. Within-pair variances for inspiratory capacity (IC), vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced mid-expiratory flow (FEV25-75%), forced end-expiratory flow (FEF75-85%), maximum expiratory flow (FEF200-1200ml), forced maximum voluntary ventilation MVVF) and PEFR were significantly smaller (p < 0.01) in MZ twins than in DZ twins. Tidal volume (VT), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), forced expiratory volume in 1 second as a percentage of forced vital capacity (FEV1%), and forced expiratory time (FET) were not significantly different. Within-pair correlations were all higher in MZ than DZ twins. All measurements except for VT and PEFR showed high levels of heritability (23-99%). All measurements were positively and significantly correlated with physical characteristics such as weight, standing height, surface area, arm-span, chest circumference and age, except FEV1% and FET. Residual values adjusted for physical characteristics showed similar results to unadjusted values in most cases. These data indicate that major lung function measurements are possibly influenced more by genetic than environmental factors. Genetically influenced measurements show higher levels of heritability estimates and suggest that genetic determination of lung function is possibly independent of the influence of physical characteristics.

Adolescent↗