Differential response of tomato and tobacco to Agrobacterium mediated transformation with cytokinin independent -1 (CKI-1) gene as influenced by cytokinin levels.

Cytokinin independent-1 (CKI-1) gene was identified through its ability to confer cytokinin independent growth in Arabidopsis which has led to this gene being advocated as a selectable marker in plant transformation. Keeping this in view, CKI-1 gene was assessed as a selectable marker by transformation of tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum L.). Overexpression of CKI-1 gene through Agrobacterium mediated transformation in tobacco and tomato conferred cytokinin independent shoot regeneration (in media devoid of cytokinin/plant growth regulators) in tobacco, but not in tomato wherein this ability (cytokinin independence) was conferred to T1 explants of CKI-1 transgenic tomato plant (T0) regenerated on cytokinin medium. Analysis of cytokinin levels revealed that cytokinin independent growth upon transformation with CKI-1 gene in tobacco (T0) and tomato (T1) was achieved through maintaining/regulating higher endogenous cytokinin levels and CKI-1 gene expression. Levels of CKI-1 transcripts assayed through quantitative RT-PCR suggested that there seemed to be a threshold level of endogenous cytokinin level, regulated due to external or internal supply via CKI-1 gene upto which CKI-1 gene expression correlated with endogenous cytokinin content and beyond that, either the gene expression was not induced or it remains same. With the incorporation of CKI-1 gene, it appeared that this threshold level of endogenous cytokinin might be reduced in crops like tomato to support shoot regeneration at lower concentration of cytokinin, but could not be made independent of external supply of cytokinin as in tobacco suggesting that use of CKI-1 gene as an effective alternate selection marker could not be universally applicable across the species. The results of the present study revealed that CKI-1 gene in addition to enhancing cytokinin levels, was also involved in contributing to the sensitivity to cytokinin and thus served as a positive regulator of cytokinin signal transduction.

Lipid profile in a tertiary care center.

INTRODUCTION: Lipid profile is changing with changing developmental status and lifestyle in less developed countries and coronary artery disease risk factor is rising. The aim of the study is to find the lipid pattern in Department of Medicine in tertiary care hospital. METHODS: An observational prospective study was conducted in 408 subjects from January 2009 to February 2010. Study subjects were selected irrespective of co-morbid condition and coronary risk factors. RESULTS: The mean triglycerides, cholesterol, LDL, HDL were 138.3 +/- 78.3 mg/dl, 180.2 +/- 53.7 mg/dl, 113.8 +/- 41.2 mg/dl, 40.1 +/- 10.1 mg/dl respectively. The Triglycerides (>140 mg/dl), Cholesterol (>250 mg/dl), LDL (>92 mg/dl), HDL (<45mg/dl) were 35.5%, 7.6%, 67.9%, 76% respectively. CONCLUSIONS: Lipid profile is becoming atherogenic with high triglyceride, high LDL and low HDL being the most common abnormality. An epidemiological study is recommended to understand the true burden of the disease in the community.

Use of hydrogen peroxide to assess the sperm susceptibility to oxidative stress in subjects presenting a normal semen profile.

Human sperm susceptibility to oxidative stress is vital as it affects various characteristics of sperm function. In the present study, we report a simple, sensitive and quick method of assessing the capacity of the sperms to withstand increased oxidative stress. The basis for the test was derived from the fact that human sperms suspended in Ham's F-10 medium tend to lose the forward progressive motility when co-incubated with H(2)O(2) (600 microm). Replacement of the medium with seminal plasma (1: 1) was able to reduce the loss of sperm motility (40%). Retention of sperm motility in semen (0-30%) following 10 min of H(2)O(2) (600 microm) exposure was taken as the criteria for delineating the quality of sperm as poor, moderate, good and excellent types. The protocol was tested in 87 subjects presenting a normal semen profile. On the basis of this test, 44% of the semen samples were classified as poor and the rest as moderate, good or excellent. Lipid peroxidation was found higher in the sperms from the 'poor' category. Activities of superoxide dismutase and catalase were also significantly elevated in the seminal plasma of these subjects as compared with combined categories of good or excellent. The test described here can be used routinely in laboratory investigations to assess sperm susceptibility to oxidative stress in subjects presenting a normal semen profile.

Biochemical toxicology of argemone oil. I. Effect on hepatic cytochrome P-450 and xenobiotic metabolizing enzymes.

The in vivo effect of argemone oil on hepatic xenobiotic metabolizing enzymes was investigated in albino rats following either a single (10 ml kg-1 body wt.) or multiple intraparenteral doses (5 ml kg-1 body wt.) for three days. Animals sacrificed 72 h after a single intraparenteral dose of argemone oil exhibited a significant loss of hepatic cytochrome P-450 (35%) and cytochrome b5 (34%) contents and inhibition of aminopyrine-N-demethylase (APD), aryl hydrocarbon hydroxylase (AHH) and ethoxycoumarin-O-deethylase (ECD) activities (21-39%). Three successive 24-hourly intraparenteral injections of argemone oil followed by sacrificing the animals after 24 h of the last injection, showed a greater degree of inhibition of the content of cytochrome P-450 (58%) and its dependent mixed-function oxidases (35-63%). Also, multiple treatment of argemone oil caused a depletion of endogenous hepatic glutathione (GSH) content (72%) with a concomitant increase in lipid peroxidation (177%) and decrease in glutathione-S-transferase (GST) activity (30%). A significant decrease in relative liver weight (39%) was observed in animals treated with multiple treatment of argemone oil. These results suggest that argemone oil can alter both membrane and cytosolic defences and destabilizes the hepatic cytochrome P-450 dependent mixed-function oxidase system, so that it tips in the direction of autooxidative peroxidation of lipids.

Role of antioxidants and scavengers on argemone oil-induced toxicity in rats.

The role of antioxidants and scavengers on argemone oil-induced enzymatic and non-enzymatic hepatic lipid peroxidation was investigated in rats. Multiple treatment of argemone oil caused a significant stimulation of NADPH-dependent enzymatic or FeSO4 or FeSO4/ADP-or ascorbic acid-dependent non-enzymatic hepatic microsomal lipid peroxidation. In vitro addition of antioxidants such as tannic acid, quercetin, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), alpha-tocopherol, riboflavin or glutathione (GSH) in the assay system resulted in significant protection against argemone oil-induced microsomal NADPH, or FeSO4/ADP-dependent lipid peroxidation. In vitro addition of scavengers of the superoxide anion (O2-.) radical and hydrogen peroxide (H2O2) such as superoxide dismutase (SOD) and catalase, respectively, prevented argemone oil augmented microsomal lipid peroxidation to a lesser extent as compared to the scavengers of singlet oxygen (1O2) such as 2,5-dimethylfuran (DMF), beta-carotene, and histidine or hydroxyl (OH.) radical scavengers such as ethanol, mannitol and sodium benzoate. These results suggest that primarily 1O2 and OH. radicals are involved in argemone oil-induced hepatic microsomal lipid peroxidation, and that bio-antioxidant vitamins including riboflavin, beta-carotene and alpha-tocopherol may prove useful in reducing argemone oil-induced hepatotoxicity.

Biochemical toxicology of argemone oil. IV. Short-term oral feeding response in rats.

Consumption of edible oils contaminated with Argemone mexicana seed oil is known to cause various clinical manifestations. In the present study, the effect of dietary intake of argemone oil on histopathological changes, haematological indices and selected marker parameters of toxicity was investigated to observe the exact sites and mode of action of argemone oil in rats. Histopathological changes in the liver showed increased fibrosis, hyperplasia of bile ducts and congestion in a few portal tracts. Lungs of argemone oil-fed animals indicated congestion and thickening of interalveolar septa. Alveolar spaces were disorganised and irregular. Kidneys showed vascular and glomerular congestion and patchy tubular lesions. At 30 days only mild congestion was noted in the myocardium. Cardiac muscle fibres showed degenerative changes at 60 days which were more marked in the auricular wall. Haematological examination showed appearance of anaemia in experimental animals. Hepatic alkaline phosphatase, alanine transaminase and aspartate transaminase activities were inhibited by 30, 29 and 29% after 30 days of argemone intake along with concomitant enhancement in serum by 27, 29 and 66%, respectively. Liver showed decrease in glutathione (32-63%) content along with significant stimulation of lipid peroxidation (49-105%) in argemone-intoxicated animals. These results suggest that liver, lungs, heart and kidneys are the target tissues of argemone oil toxicity and that membrane destruction may be a possible mode of action.

Biochemical toxicology of argemone alkaloids. III. Effect on lipid peroxidation in different subcellular fractions of the liver.

Consumption of edible oils contaminated with Argemone mexicana seed oil causes various toxic manifestations. In this investigation the in vivo effect of argemone oil on NADPH-dependent enzymatic and Fe2+-, Fe2+/ADP- or ascorbic acid-dependent non-enzymatic hepato-subcellular lipid peroxidation was studied. Parenteral administration of argemone oil (5 ml/kg body weight) daily for 3 days produced a significant increase in both non-enzymatic and NADPH-supported enzymatic lipid peroxidation in whole homogenate, mitochondria, and microsomes. Lipid peroxidation aided by various pro-oxidants, namely Fe2+, Fe2+/ADP and ascorbic acid also revealed a significant enhancement in the whole homogenate, mitochondria and microsomes of argemone oil-treated rats. Further, when compared with whole homogenate, the hepatic mitochondria and microsomes of either control or argemone oil-treated rats showed a 4- and 6-fold increase in non-enzymatic, and a 5- and 18-fold increase in NADPH-dependent enzymatic lipid peroxidation, respectively. Similarly, both mitochondrial and microsomal fractions showed a 5- and 7-fold increase in Fe2+-, and a 12- and 15-fold increase in either Fe2+/ADP- or ascorbic acid-aided lipid peroxidation, respectively. These results suggest that the hepatic microsomal as well as the mitochondrial membrane is vulnerable to the peroxidative attack of argemone oil and may be instrumental in leading to the hepatotoxicity symptoms noted in argemone poisoning victims.