Ribonucleic acids from barley leaves

1. The total RNA and the RNA present in 27000g pellet (probably composed of chloroplasts, nuclei and mitochondria) and in 27000g supernatant (probably composed of microsomes and soluble proteins) fractions (separated by centrifugation at 27000g of a leaf homogenate prepared in 0·5m-sucrose–0·02m-tris–HCl, pH7·6) of barley leaves were extracted by phenol–sodium lauryl sulphate and their elution profiles on Sephadex G-200 and on ECTEOLA-cellulose anion-exchanger were examined and their nucleotide compositions and the melting curves were determined. 2. The pellet and the supernatant fractions contained respectively about 55% and 20% of the total RNA, whereas 25% of the total RNA was lost during homogenization of the leaf tissue with sucrose–buffer. 3. The total RNA or the RNA from pellet or supernatant fractions, which by its behaviour on Sephadex G-200 columns was found to be predominantly of high molecular weight (i.e. of ribosomal origin), produced about 13 peaks on ECTEOLA-cellulose columns. The RNA species in the pellet and supernatant fractions probably resembled each other in molecular size or secondary structure or both. However, they were present in relatively different amounts in these fractions. 4. The T_m (i.e. the temperature at which 50% of the maximal increase in extinction had occurred) of total RNA and of RNA from pellet fraction was 64·5° whereas T_m of RNA from the supernatant fraction was 73°. The total RNA and the RNA from pellet fraction also resembled each other in nucleotide composition, and the RNA from the supernatant fraction in accordance with its high T_m had a high GMP+CMP content.     

Protection by Desferrioxamine Against Histopathological Changes of the Liver in the Post-Oligaemic Phase of Clinical Haemorrhagic Shock in Dogs: Correlation with Improved Survival Rate and Recovery

Haemorrhagic shock was produced in anaesthetized dogs, by rapid arterial bleeding to mean arterial blood pressure 35 mmHg, and maintained oligaemic for 4 h followed by return of withdrawn blood(R0WB). Dogs were observed for 72 h after ROWB for survival and recovery, and, for histopathological (HP) studies on liver, dogs were sacrificed 2 h after ROWB in non-survival experiments. Desferrioxamine mesylate (25mg/kg) was administered intra-muscularly at 2,3 and 4h after blood loss in survival experiments and for HP studies the drug was given at 4 h in one group and at 2 h plus 4 h after blood loss in the second group. With the drug given at 3 or 4h, survival was 70% and 100% while in the 2h and the untreated groups it was 50%. Recovery was rapid in all the drug treated survivors, few became conscious within 30min. showed slight activity by 4-6 h, all were almost normally active by 24 and fully so by 72 h after ROWB. All the 5 control survivors remained unconscious/drowsy upto 24 h; 3 were sluggish at 72 h. By group analysis, serum iron elevation during the oligaemic and at the end of the post-oligaemic phase was less in the drug-treated animals. HP changes of shock in the liver studied by light microscopy, were markedly reduced in severity and were less prevalent in the drug-treated dogs. The salutory effects of desferrioxamine may be due to inhibition of iron catalyzed free-radical production and tissue damage, through its strong iron chelating action. It may have a therapeutic advantage in this emergency condition without the disadvantages of toxicity inherent in prolonged use.     

Bionomics ofTrioxys indicus [Hym.: Aphidiidae], a parasitoid ofAphis craccivora [Hem.: Aphididae]: 31. Effect of host haemolymph on the numerical response of the parasitoid

The influence of kairomones on the numerical response of the parasitoidTrioxys indicus against its hostAphis craccivora at its varying density was studied. The kairomones (applied as aqueous extract of the host) significantly enhanced the rate of parasitisation and multiplication and the area of discovery of the parasitoid and also the K-values of mortality of the host at all parasitoid densities introduced (1, 2, 4, 8, 12 and 16 parasitoids) into troughs having about 200 hosts. The sex-ratio of F₁ offspring decreased at lower parasitoid densities and remained more or less unchanged at higher parasitoid densities after the application of kairomones. The present findings indicate that if kairomones are applied properly, the number of hosts destroyed by a stimulated parasitoid will be about 200, twice the number reported earlier, thus fewer parasitoids will be needed to regulate an estimated population of the hosts.      

Tissue culture and plant regeneration of watermelon (Citrullus vulgaris Schrad. cv. Melitopolski)

Plants were regenerated from cotyledon and hypocotyl explants of watermelon (Citrullus vulgaris). The explants were cultured on a Murashige and Skoog's basal nutrient medium supplemented with auxin, cytokinin and auxin-cytokinin combinations. Green healthy nodular and compact callus was obtained in medium containing naphthalene acetic acid and benzylaminopurine. Shoot differentiation and root differentiation from the cotyledon and hypocotyl after callus formation in different media containing benzylaminopurine or naphthalene acetic acid, respectively. Shoot formation required benzylaminopurine. Kinetin proved ineffective in inducing shoot buds or shoots. Root differentiation occurred in a medium containing naphthalene acetic acid or indole acetic acid. There was a greater proliferation of roots on medium supplemented with naphthalene acetic acid. The regenerated shoots developed roots when transferred to medium containing naphthalene acetic acid and complete plantlets could be transferred to soil for further growth.Abbreviations BAP 6 Benzylaminopurine - NAA -Naphthalene acetic acid - MS Murashige and Skoog's medium - IAA Indole acetic acid - KN Kinetin     

Extracts from two frequently consumed spices--cumin (Cuminum cyminum) and turmeric (Curcuma longa)--inhibit platelet aggregation and alter eicosanoid biosynthesis in human blood platelets

In the traditional Indian system of medicine, Ayurveda, several spices and herbs are claimed to possess medicinal properties, such as being antithrombotic, antiatherosclerotic, hypolipidemic, anti-inflammatory etc. Earlier we have reported that extracts from several spices behave as antiaggregatory agents and inhibit eicosanoid synthesis. Similar studies with extracts prepared from cumin (Cuminum cyminum) and turmeric (Curcuma longa) were undertaken. Ethereal extract of both cumin and turmeric inhibited arachidonate-induced platelet aggregation. Extracts from these spices inhibited thromboxane B2 production from exogenous (14C) arachidonic acid (AA) in washed platelets; a simultaneous increase in the formation of lipoxygenase-derived products was observed. Less TxB2 was produced in blood samples treated with turmeric extract when they were allowed to clot. Turmeric extract inhibited incorporation of (14C)AA into platelet phospholipids and deacylation of AA-labelled phospholipids on stimulation with calcium ionophore A23187. Cumin extract was devoid of such effects. Extracts from the two spices reduced the formation of (14C)TxB2 from AA-labelled platelets when they were challenged with A23187. The anti-inflammatory property of turmeric may, in part, be explained by its effect on eicosanoid biosynthesis.     

Studies on lactic dehydrogenase and sorbitol dehydrogenase release in relation to deep freezing of buffalo semen in certain extenders

Forty seminal ejaculates from five mature buffalo bulls (n=8 from each bull), exhibiting more than 70% initial sperm motility, were frozen in the following three extenders: egg-yolk sodium citrate glycerol (EYCG); tris-egg yolk glycerol (TYG); and citric acid whey glycerol (CAWG). The extenders were evaluated for the release of intracellular enzymes, lactic dehydrogenase (LDH) and sorbitol dehydrogenase (SODH) from the spermatozoa during freezing (in fresh semen, after dilution and after equilibration) and post freezing (24 h and 7 d after freezing. It was found that the release of LDH and SODH enzymes was significantly lower in TYG than in EYCG and CAWG extenders. The most critical stage, at which the enzyme release was maximal, was between equilibration and 24 h post freezing in all three extenders.