Hydrogen peroxide-scavenging enzymes impart tolerance to high temperature induced oxidative stress in sugarcane.

Seventy-one genotypes of sugarcane from diverse agro-climatic zones of India viz. peninsular, northwest, north-central and eastern zones, were screened for their tolerance to high temperature stress based on the damage to leaf biomass i.e. necrosis of leaf-tips and margins, and rolling of leaves. Nine selected genotypes showing variable response to heat injury were tested for activity pattern of isoforms of two H2O2-scavenging enzymes; ascorbate peroxidase (APX) and catalase (CAT), under high temperature induced oxidative stress. Changes in the activity of APX and CAT isozymes in leaves corresponded to the level of tolerance of genotypes towards heat injury which was substantiated by the highly negative correlation coefficients of heat injury levels of leaves vs. integrated density of APX and CAT isozyme bands. This indicated that the criteria of higher expression of CATs’ and APXs’, the two major reactive oxygen species scavenging proteins in leaves may be used to screen large seedling populations and germplasm for high temperature tolerance.

A study to characterize the influence of outdoor SPM and associated metals on indoor environment in Delhi.

In order to understand the influence of outdoor SPM and its associated metals on indoor environment, a study was carried out for 24 residential, sensitive, commercial and heavy traffic sites in Delhi. In the first phase, the samplings of SPM were conducted simultaneously indoors and outdoors at a reference site during February to March 2000 and later at all other sites from February to July 2001. Atomic Absorption Spectrometry (AAS) was used to determine the heavy metal composition of SPM, analyses of Ca, Mg, Cu, Cd, Pb, Cr, Mn, Fe and Ni were done. It is observed that, depending upon the nature of the site, the outdoor SPM concentrations affect the indoor SPM concentrations in varying degrees. In case of metals such as Cu, Cr, Cd and Ni, very good correlation between the indoor and outdoor concentrations was observed irrespective of the nature of the site. The correlation between indoor and outdoor for Mg, Fe, Mn and Pb depends upon the nature of the site. No correlation was observed between indoor and outdoor Ca at any of the chosen sites.

Acute Promyelocytic Leukemia : Experience at a North Indian Tertiary Care Hospital with Review of Literature

Acute promyelocytic leukemia (APL) is characterised by balanced translocation between the long arms of chromoso)ne 15 and 17 resulting in formation of fusion protein PML/RARa. Due to this abnormal fusion protein, myeloid cell differentiation is arrested at the promyelocyte level. This molecular defect and myeloid cell differentiation arrest can be overcome by pharmacologic doses of ali-trans retinoic acid (ATRA). APL most common Iy presents as catastrophic bleeding manifestations which is a major cause of mortality. If diagnosed and treated early, patients can be salvaged and can achieve long term disease free survival. Our experience of seven patients is presented. All patiens presented with bleeding manifestation and two died due to it. Rest of the five patients who underwent chemotherapy in the form of induction with ATRA along with supportive measures (fresh frozen plasma and platelets) followed by consolidation therapy in the form of multi-agent chemotherapy, achieved prolonged disease free remission. Thus with early diagnosis and start of ATRA, APL is a potentially curable malignancy.