Thermal stress and physiological strain in the glass bangle industry

A preliminary survey of the few units of the small-scale glass bangle industry in Firozabad, Agra District, Uttar Pradesh, indicated that the workers were exposed to severe degrees of heat stress during various operations in the manufacturing processes. A more detailed study in eight glass bangle units was therefore undertaken to make quantitative estimates of heat stress on exposed workers in the summer season. The thermal data collected confirmed that the heat stress on the workers was severe but measurement of certain physiological indicators revealed relatively low levels of strain amongst the exposed workers. The findings could be attributable to high degrees of acclimatization, but further observations in the field supplemented by studies on simulated exposures of volunteers in a climatic chamber seem to be warranted.     

Irreversible platelet aggregation does not depend on lipoxygenase metabolites

Previous investigations in our laboratory demonstrated the existence of an intrinsic mechanism, termed membrane modulation, capable of restoring sensitivity to aspirin treated platelets, resulting in irreversible aggregation in response to arachidonic acid (AA). The mechanism underlying correction of aspirin induced inhibition of platelet function, however, was not clear. In the present study we have evaluated the role of lipoxygenase (LO) metabolites of AA in securing irreversible aggregation of drug induced cyclooxygenase (CO) deficient platelets. Platelets treated with aspirin or Ibuprofen did not convert radiolabeled AA to thromboxane, but generated significant quantities of hydroxy acids via the LO pathway. However, drug exposed platelets, when stirred with epinephrine first and then challenged with AA, aggregated irreversibly. Eicosatetraynoic acid (ETYA 1, U53119) inhibited AA conversion by the LO pathway, whereas 5,8,11,14-eicosatetraynoic acid (ETYA 2) inhibited AA conversion by both CO and LO enzymes. Yet, at the inhibitory concentration these fatty acids failed to prevent AA induced irreversible aggregation of CO deficient, alpha adrenergic receptor stimulated platelets. Results of four studies show that the generation of LO metabolites of AA are not essential for securing irreversible aggregation of platelets.     

Mitogen-like monoclonal anti-actin antibodies

Monoclonal antibodies (IgM kappa) have been produced to actin isolated electrophoretically from L cell extracts. These monoclonal anti-actin antibodies bind to intact L cells and modulate DNA synthesis and cell proliferation, much like affinity-purified polyclonal rabbit antibody to the same Mr 42,000 actin. In addition, monoclonal antibodies specific for actin from Entamoeba histolytica also bound to and modulated the growth of L cells. A monoclonal antibody directed against a neuroblastoma surface antigen did not produce stimulation of L cells, and the binding activity of anti-actin monoclonal antibody to L cells was removed by absorption with actin covalently coupled to Sepharose. These observations demonstrate the specificity of interaction between the anti-actin monoclonal antibodies and the surface of intact L cells. We conclude that a surface actin-like molecule on the L cell, when bound by specific monoclonal antibody, initiates a stimulatory signal which results in enhanced cellular metabolism.     

In vitro effect of prostaglandins,prostaglandin endoperoxides and thromboxane on rat intestinal alkaline phosphatase and (Ca2+-Mg2+) adenosine triphosphatase

The activity of alkaline phosphate and²⁺-Mg²⁺ adenosine triphosphatase, two of the enzymes involved in limpid and calcium uptake across the intestinal membrane, were increased in experimental atherosclerosis. Administration ofAnnapavala sindhooram, an antiatherosclerotic drug, lowers these enzyme levels to near normal values. Prostaglandin E2 stimulated the enzyme activitiesin vitro, while prostaglandin endoperoxide inhibited the activity. Thromboxane and other prostaglandins had no effect on the enzyme activities. Addition of the antiatherosclerotic drug to thein vitro assay system reversed the effect of both prostaglandin E₂ and prostaglandin endoperoxide.     

Changes in carbohydrates and lipids during embryonic development ofAntheraea mylitta (Lepidoptera)

Changes in carbohydrate and lipid metabolism during embryonic development inAntheraea mylitta were studied. While carbohydrates were metabolized during early embryogenesis, lipids were catabolised at the later stages. A significant increase in both total carbohydrates and glycogen on days 5 and 6 suggested the concurrent occurrence of both gluconeogenesis and glycogenesis. As the development of the embryo proceeds, both lipids and carbohydrates were utilised, resulting in the increase in the concentration of citrate, pyruvate and lactate.     

Major vault protein (MVP) gene polymorphisms and drug resistance in mesial temporal lobe epilepsy with hippocampal sclerosis

The human major vault protein (MVP) has been implicated in the development of drug resistance in cancer cells. Over expression of MVP has also been reported in brain tissue samples from antiepileptic drug (AED)-resistant human focal epilepsies. To investigate the relationship between single nucleotide polymorphisms (SNPs) involving the MVP gene and AED-resistance, we compared the distribution of three SNPs in the MVP gene, rs4788187, rs3815824 and rs3815823, among 220 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (prototype of AED-resistant epilepsy syndrome), 201 patients with juvenile myoclonic epilepsy (JME) (prototype of AED-responsive epilepsy syndrome) and 213 ethnically matched non-epilepsy controls. All the patients and controls were residents of the South Indian state of Kerala for more than three generations. We did not find any significant difference in allele and genotypic frequencies of the studied SNPs between AED-resistant and AED-responsive cohorts, and between AED-resistant and AED-responsive cohorts independently and pooled together when compared with the controls. We conclude that rs4788187, rs3815824, rs3815823 variants of the MVP gene are associated neither with predisposition for epilepsy nor with AED-resistance in the population that we have studied. Our results suggest the need for further research into the link between MVP and AED-resistance.