Hexokinase, glucose-6-phosphate dehydrogenase and antioxidant enzymes in diabetic reticulocytes: effects of insulin and vanadate.

Experimentally induced diabetic rats were treated separately with insulin and vanadate. The activities of hexokinase (HK) and glucose-6-phosphate dehydrogenase (G-6PDH) were increased in reticulocyte hemolysate isolated from the diabetic rats and were restored to normal levels by insulin. The restoration was not detected in vanadate treated diabetic animals. The enzymes of glutathione metabolism namely glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-s-transferase (GST) exhibited increases in their activities with diabetes and were restored to almost control values by insulin treatment. Vanadate given to diabetic animals further increased GPx, and GST. The level of superoxide dismutase(SOD) decreased in the reticulocytes of diabetic rats and catalase (CAT) was unchanged. Both CAT and SOD had normal values when the diabetic rats were treated with insulin and vanadate. It is proposed that vanadate may cause an increase in the activity of GR which may stimulate glucose transporters and glucose metabolism.

Effect of experimental diabetes on the activities of hexokinase, glucose-6-phosphate dehydrogenase and catecholamines in rat erythrocytes of different ages.

Hexokinase and glucose-6-phosphate dehydrogenase were assayed in various circulating age fractions i.e., young, middle-aged and old red cell from control, diabetic and insulin-treated diabetic rats. An increase in the activity of hexokinase was observed in three age-wise separated fractions of red cells from diabetic animals in comparison to control. The activity of glucose-6-phosphate dehydrogenase on the other hand decreased in separated ageing fractions of diabetic red cells when compared to control. Reversal of these two enzymes were observed in insulin-treated diabetic rats. The levels of glycosylated haemoglobin and catecholamines were found to increase with ageing red cells in controls and also increased in red cells plasma.

Adenosine deaminase activity in typhoid fever.

Serum adenosine deaminase (ADA) activity was determined in 41 patients of typhoid fever and 15 normal controls. The mean ADA activity was significantly raised in typhoid fever patients as compared to controls (p < 0.001). The peak enzymatic activity was observed in the first week of illness. Complicated patients had lower mean ADA activity at diagnosis as compared to uncomplicated group and they showed a rise in enzyme level during defervescence, repeated in a few cases. A significant correlation between serum ADA activity and lymphocyte percentage was found (r = 0.4245, p < 0.001). It is concluded that ADA activity in typhoid fever patients not only indicates immunity but also has a prognostic value.

Ageing erythrocytes and alloxan diabetes: II. Role of thyroxine in reversing diabetic state.

The erythrocytes from control (C), diabetic (D) and thyroxine-treated diabetic (D+T4) rats were separated into three ageing groups (TAG) like light dense (young cells), intermediate-dense (middle-aged cells) and heavy-dense (old aged cells). Thyroxine reversed the diabetic defense enzymes to normal values like catalase in young cells, glutathione-s-transferase in middle-aged and old cells and levels of GSH in middle-aged cells. Thyroxine also increased the levels of GSSG in TAG whereas the levels of GSH increased in young cells, and decreased in old cells. The percentage of glycosylated haemoglobin did not return to normal levels by thyroxine in diabetic animals. Thyroxine may be playing the dual role in increasing the sulfhydryl levels and also inactivating enzymes in ageing erythrocytes of diabetic animals.

Choice of antibiotics for empiric treatment of serious infections.

We have compared the in vitro activity of commonly used aminoglycosides--Gentamicin and Amikacin with Ciprofloxacin to determine whether the latter has any role in the empiric treatment of serious bacterial infections. Our results indicate that ciproloxacin was comparable or had a better activity than gentamicin or Amikacin against clinical isolates. As it can be administered orally, hospitalization can be avoided in a large number of patients.

Ageing erythrocytes and alloxan diabetes: I. A possible role of catalase, GSH, GSSG, and GSH-enzymes in decreasing defence system.

The erythrocytes from control (C), diabetic (D) and insulin-treated diabetic (D+I) rats were separated into three ageing groups (TAG) i.e., light dense (young cells), intermediate-dense (middle-aged cells) and heavy-dense (old aged cells) samples. The activities of enzymes and metabolites changed from young to old cells in the following manner: (1) Increase of CAT in TAG and a lower level in D and D+I (2) Decrease of GPx in TAG but a low level in D (3) Increase of GR in TAG but a higher level in D, (4) Increase of GST in C and a decrease in D with a higher level in young cells and a lower level in middle-aged and old cells. The reversal of enzyme was more in young cells of D+I (5) Increase of GSH in TAG, a low level in D and a high level in D+I (6) Increase of GSSG in TAG, a high level found only in young cells of D. The results show that young red cells are affected more significantly in diabetes than other age cell types.

In vitro effect of testosterone propionate on lactate dehydrogenase and malate dehydrogenase in brain and gonads of Channa punctatus.

The activities of lactate dehydrogenase (LDH), malate dehydrogenase (MDH), and protein levels were measured in vitro incubation of tissue homogenate of brain and gonads with testosterone propionate (TP) in Channa punctatus (teleost). The activities of LDH and MDH were found to be highest in the ovarian tissues in comparison to the testis and the brain in control fish. TP (2 micrograms-4 micrograms/ml) stimulated testicular tissue with increases in LDH by 10-fold and MDH by 15-fold approximately, the ovary with significant increase in LDH and a decrease in MDH and the brain showed only an increase in MDH.

Effect of insulin and thyroxine on catalase, glutathione-s-transferase, GSH and GSSG in alloxan diabetic rat red cells.

The levels of catalase (CAT), glutathione-s-transferase (GST), reduced glutathione (GSH) and oxidised glutathione (GSSG) were measured in red blood cells from control (C) and diabetic rats (D). Diabetes was induced by alloxan administration and diabetic rats were treated with insulin (D+I) and thyroxine (D+T4). On the third day of insulin withdrawal the CAT activity increased significantly. The GST activity showed an increase in D and D+I for one week, thyroxine treatment to D rats resulted in maintaining the GST activity at control levels. The levels of GSH and GSSG increased in D red cells after one week of insulin withdrawal but later, the GSH level was below the control level while the GSSG was at its control level. Insulin treatment to D rats did not reverse GSH level to control initially but controlled it at a later stage. Thyroxine, though, reversed GSH levels but enhanced GSSG in D rat red cells.

Multidrug resistant Salmonella typhi in Delhi.

In 1990, we isolated 158 strains of Salmonella typhi from blood cultures of patients suffering from typhoid fever. Seventy nine (50%) of these isolates were found to be simultaneously resistant to chloramphenicol, ampicillin and cotrimoxazole. These strains were also resistant to streptomycin and tetracycline, but sensitive to gentamicin, amikacin and cephalexin. The minimum inhibitory concentrations of chloramphenicol and trimethoprim for a representative number of these strains were found to be greater than 1024 micrograms/ml and greater than 128 micrograms/ml respectively. Majority of the multidrug resistant (MDR) strains tested against cefotaxime (23/23), ciprofloxacin (38/38) and amoxycillin plus clavulanic acid (23/24) were sensitive to these drugs.

Determination of fluoride in zinc concentrates, processing products and solutions with an ion-specific electrode.

Determination of fluoride in hydrometallurgical zinc-plant processing products and solutions with a fluoride-ion electrode is described. Various types of buffers were tested, to find a suitable common buffer for use in analysis of all types of substances generated at the zinc plant. The method involves decomposition of samples either by fusion with sodium hydroxide or by leaching with perchloric acid to bring fluoride into solution. The fluoride concentration is measured directly with a fluoride-specific electrode. In standard addition tests 100% recovery was obtained when a citric acid/sodium nitrate buffer was used. Validation tests gave satisfactory results.

Ted Hall and the science of biological microprobe X-ray analysis: a historical perspective of methodology and biological dividends.

This review surveys the emergence of electron probe X-ray microanalysis as a quantitative method for measuring the chemical elements in situ. The extension of the method to the biological sciences under the influence of Ted Hall is reviewed. Some classical experiments by Hall and his colleagues in Cambridge, UK, previously unpublished, are described; as are some of the earliest quantitative results from the cryo-sections obtained in Cambridge and elsewhere. The progress of the methodology is critically evaluated from the earliest starts to the present state of the art. Particular attention has been focused on the application of the method in providing fresh insights into the role of ions in cell and tissue physiology and pathology. A comprehensive list of references is included for a further pursuit of the topics by the interested reader.

Changes in erythrocyte glutathione peroxidase and glutathione reductase in alloxan diabetes.

Glutathione peroxidase and glutathione reductase activities were measured in erythrocytes from control, diabetic and insulin-treated diabetic rats. A significant decrease in the activity of glutathione peroxidase and an increase in the glutathione reductase activity were found with increase in the time of diabetes which may result in the alteration in the activity of the pentose phosphate pathway by the modulation of the levels of NADPH. Insulin administration reverses the change in the activity of glutathione peroxidase but does not reverse the glutathione reductase activity during diabetes. The overall changes may be due to changes in the levels of insulin, triiodothyronine and thyroxine.

Effect of hyperthyroidism and hypothyroidism on rat red blood cell insulin receptors and catecholamines: relationship with cellular ageing.

Insulin receptor activity and its relationship with catecholamines in rat young, middle aged and old red blood cells were investigated in experimental hypothyroidism and hyperthyroidism. In control animals, a loss of insulin receptor activity was found with cellular ageing and increased levels of norepinephrine, epinephrine and glycosylated hemoglobin. There was down regulation of insulin receptors together with alterations in membrane bound catecholamines in thyroid hormones imbalances. These results suggest that loss of insulin receptor in cellular ageing is probably part of a more generalised alteration and rat serves as an excellent model in defining the role of thyroid hormones in carbohydrate tolerance.

Rat brain insulin degrading enzyme in insulin and thyroid hormones imbalances.

Rat brain insulin degrading enzyme activity and its relationship with insulin receptor were investigated in experimental hyperglycemia, hyperinsulinemia, hypothyroidism and hyperthyroidism. Insulin degrading enzyme activity was assessed in synaptosomes and high speed cytosol using [125I]insulin. Levels of insulin degrading enzyme were changed in high speed cytosol in insulin and thyroid hormone imbalances. These results suggest that insulin degrading enzyme in brain is predominantly active in cytosol and is subject to regulation by insulin and thyroid hormones. Probably it plays some role in long term effects of insulin in brain.

Susceptibility of clinical isolates to cephalexin, cefazolin and cefotaxime.

Three hundred and seventeen recent clinical isolates were tested for in vitro susceptibility to the three cephalosporins available in India--cephalexin, cefazolin and cefotaxime by the Kirby--Bauer disc diffusion method. Cefazolin was the most effective cephalosporin against Gram positive cocci (71.8% sensitive) followed by cefotaxime (62.7%) and cephalexin (52.7%). Cefotaxime was very effective against commonly isolated Gram negative bacilli with only 10 (8.8%) isolates being resistant to it while 44 (39%) and 65 (57.5%) were resistant to cefazolin and cephalexin, respectively. All isolates of Pseudomonas aeruginosa were resistant to cephalexin and cefazolin and only 29 (32.6%) were sensitive to cefotaxime.