Bombesin analogs containing alpha-amino-isobutyric acid with potent anticancer activity.

Six octapeptide bombesin (BN) analogs were synthesized by substituting alpha-aminoisobutyric acid (Aib), in place of Ala9 or Gly11, or both, in the [D-Phe6, desMet14]-BN (6-14) sequence: D-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Leu13-NH2 (P0). Additionally, Leu13 was replaced with isoleucine in two analogs and one of the analogs was butanoylated at the N-terminus. The antiproliferative activity of the analogs was tested in vitro on human pancreatic (MiaPaCa-2) and colon cancer (SW620, HT29 and PTC) cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The analogs demonstrated anticancer activity in the above cell lines at concentrations ranging from 0.01 nM to 1 microM. One of the analogs, P6, was evaluated for in vivo tumor regression in a xenograft model of human primary colon cancer in athymic nude mice and was found to cause significant reduction in tumor volume. NMR and molecular dynamics (MD) simulation studies for this analog revealed the presence of a mixed 3(10)/alpha-helical structure. This study demonstrates that the designed BN analogs retain their anticancer activity after the incorporation of the constrained amino acid, Aib, and are potential molecules for future use in cancer therapy and drug targeting.     

In vitro regulation of 3-hydroxy-3-methylglutarylcoenzyme A reductase and acylcoenzyme A: cholesterol acyltransferase activities by phosphorylation-dephosphorylation in rabbit intestine

The regulation of 3-hydroxy-3-methylglutarylcoenzyme A reductase and acylcoenzyme A:cholesterol acyltransferase activities by phosphorylation-dephosphorylation in rabbit intestine was studied in vitro. Preparing intestinal microsomes in the presence of 50 mM NaF caused a 64% decrease in the reductase activity. It had no effect on acyl-CoA:cholesterol acyltransferase activity. Microsomes that were prepared in NaF were incubated with intestinal cytosol, a partially purified phosphatase from cytosol, and Escherichia coli alkaline phosphatase. All three preparations increased 3-hydroxy-3-methylglutaryl-CoA reductase by two- or three-fold suggesting dephosphorylation and 'reactivation' of enzyme activity. Cytosol caused a 78% increase in acyl-CoA:cholesterol acyltransferase activity, but neither the partially purified phosphatase nor the E. coli alkaline phosphatase affected the acyltransferase activity. Microsomes incubated with increasing concentrations of MgCl2 and ATP decreased both the activities of 3-hydroxy-3-methylglutaryl-CoA reductase and acylcoenzyme A:cholesterol acyltransferase in a step-wise fashion. Whereas this inhibitory effect was specific for reductase, the effect on acyl-CoA:cholesterol acyltransferase activity was secondary to the presence of ATP in the assay mixture. The 8500 X g supernatant of intestinal whole homogenate from isolated intestinal cells or scraped mucosa was incubated with MgCl2, ATP and NaF. In microsomes prepared from this supernatant, the activity of 3-hydroxy-3-methylglutaryl-CoA reductase was significantly decreased. Again, no change was observed in the acyltransferase activity. The rate of cholesterol esterification in isolated intestinal cells was not affected by 0.1 mM cAMP or 50 mM NaF. We conclude that under conditions which regulate 3-hydroxy-3-methylglutaryl-CoA reductase activity in rabbit intestine by phosphorylation-dephosphorylation, no regulation of acyl-CoA:cholesterol acyltransferase activity is observed.     

Increased production of lipoxygenase products by cholesterol-rich mouse macrophages

The metabolism of arachidonic acid by cholesterol-enriched resident mouse peritoneal macrophages was investigated. The amounts of monohydroxyeicosatetraenoic acid (mono-HETE) produced by the cholesterol-rich macrophages were 2.5-fold greater when compared to control macrophages. The major lipoxygenase product, identified by high-performance liquid chromatography in both macrophages was 12-HETE. Since macrophages are important participants in the formation of atheromatous lesions, the increased metabolism of arachidonic acid to HETE products by cholesterol-rich macrophages could contribute to the initiation and progression of the atherosclerotic process.     

The positional distribution of fatty acids in phospholipids ofFusarium oxysporum

Fusarium oxysporum, when cultured in the basal synthetic medium, synthesized as much as 26.4 % lipids. TLC analysis of total lipid shows the presence of two main classes of lipids,viz. glycerophospholipids and triacylglycerols, the latter being predominant. The major glycerophospholipid is phosphatidylcholine, the others being phosphatidylethanolamine and phosphatidylinositol.     

Vitamin A economy of the developing chick embryo and of the freshly hatched chick

1. The changes in the net amounts of retinol, retinyl esters and retinal in both the developing chick embryo and the newly hatched chick were investigated. The embryo requires about 68nmol of the vitamin for its growth, whereas the baby chick requires about 108nmol during the first 7 days after hatching. 2. Retinal was present in the egg in fairly high concentrations at the beginning of the incubation but it virtually disappeared from the extra-embryonic tissue after day 17 of incubation. It was not found in the liver of the embryo or of the newly hatched chick up until day 7.     

Epidemiological,Clinical, and Biochemical Study of Endemic Dental and Skeletal Fluorosis in Punjab

The incidence of dental fluorosis in 46,000 children in the Punjab was assessed and compared with the fluoride content of their water supplies. Ten villages were selected for more detailed studies of skeletal as well as dental fluorosis.Factors other than the fluoride contect of the drinking water which were found to influence the incidence and the severity of fluorosis were the chemical composition of the water and in particular its calcium content; the duration of exposure; sex and occupation; nutritional status; and climatic and geological variations. The role of fluoride-containing foodstuffs has yet to be assessed.     

The effect of porcine calcitonin on plasma calcium in Channa punctatm Bloch

The effect of porcine calcitonin on the plasma calcium of the freshwater Indian murrel, Channa punctatus Bloch has been studied. An injection of 200 MRC mU of porcine calcitonin was given intraperitoneally, while control fish received the gelatin carrier. A significant hypocalcaemia was noted I h after calcitonin treatment (P < 0.001). The plasma calcium had returned to the normal level by the 6th h.     

Studies of soil moisture stress in barley (Hordeum vulgare L.)

Summary The objective was to find the optimum range of water contents for inducing better growth, physiological efficiency and yield potential of barley plants (Hordeum vulgare L. var. K18). A pot culture experiment was conducted in the Division of Crop Physiology and Biochemistry Kanpur-2. The plants were subjected to various soil moisture stresses,i.e., 0.15, 0.30, 0.45, 0.60 and 0.75 atm tension throughout the crop growth period measured by irrometers.Plants maintained at 0.45 soil moisture tension required 19.07 litre of water and had the best water use efficiency (1765 mg dm/litre of water) which favourably influenced the leaf water balance (85.9%), plant growth as measured by plant height (85.4 cm) and tiller production (35.6) per hill, photosynthetic efficiency (2.185 mg CO₂/g dm/h), grain number (722) and grain yield (33.7 g) per hill while plants irrigated at a tension greater than 0.45 SMT did not develop as well. However, protein and gluten percentage increased gradually with the subsequent increase in soil moisture tension. On the other hand respiration rate (2.090 mg CO₂/g dm/hr) and leaf area (4375 cm²) were recorded to be the highest at 0.60 and 0.30 atm SMT respectively.Thus it is suggested that for reaping high harvest of barley crop, the physiological need of water (19.07 litre) in total of plant life should be made available through scheduled irrigation based on maintenance of plant at 0.45 SMT from seeding to maturity.