Effects of indomethacin and prostaglandins on ovulation of goldfish

A technique is described whereby elevated temperature and HCG injection yield a high percentage of ovulation in gravid goldfish. Indomethacin (10 μg/g; i.p. injection) completely inhibits ovulation if given within 6 hours following HCG (4 IU/g); the unovulated oocytes develop rapidly into corpora atretica. PGE₁, PGE₂, and PGF_2α (5 μg/g; i.p. injection) induce ovulation in fish treated with indomethacin and HCG; PGE₂ was most effective when given 11 hours after HCG. The results suggest that the ovulatory action of prostaglandins following HCG stimulation is at the level of the ovary and that it is restricted to a period between 7 and 12 hours after the gonadotropin injection.     

Alkaline and acid phosphatase in the intestines of rats infected with a virulent strain of Entamoeba histolytica and treated with emetine and Flagyl

The distribution patterns of alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2) in the intestine of rats inoculated intracaecally with a virulent strain of Entamoeba histolytica and treated with emetine hydrochloride and metronidazole (Flagyl) were studied. The caecum and the large intestine showed a highly significant increase in alkaline phosphatase activity after amoebic inoculation, and the enhanced activity was lowered by emetine and Flagyl treatment. There was no significant increase in acid phosphatase activity either in the caecum and the large intestine or in the small intestine (ileocaecal end). Intracaecal inoculation of bacterial associates alone from E. histolytica cultures did not produce any significant change in the level of these enzymes in the intestine.     

Rhizophagus in Mycorrhizal Association with Litchi chinensis Sonn

The morphology and the mycotrophic habit of a new species ofRhizophagus in mycorrhizal association with the roots ofLitchi chinensis Sonn a tropical fruit tree, has been described. It belongs to the vesicular-arbuscular group of phycomycetous endophytes and has been namedRhizophagus litchii sp. nov.The endophyte could not be brought into culture in artificial media, the presence of living litchi roots was necessary for its growth and development.Root penetration of the endophyte was through the epidermal cells. Roots hairs were free from infection.Part of the thesis submitted byS. Pandey for the award of the degree of Doctor of Philosophy from Bhagalpur University, Bhagalpur, Bihar (India).     

Observations on Compsopogon iyengarii Krishnamurthy (Rhodophyceae)

The structure and reproduction of Compsopogon iyengarii Krishnamurthy collected from the river Yamuna at Allahabad have been studied both in nature and cultures. Certain branches produced by proliferating cortical cells may bear monoaplanospore like structures. Monoaplanospores and microaplanospores may germinate in situ under cultural conditions. Stages in development and germination of microaplanospores have been investigated.     

Genetic transformation and “graft-hybridization” in flowering plants

Summary Recent pollination experiments with highly irradiated (100,000 r) pollen in Nicotiana have shown that radiation-pulverized pollen chromatin can cause genetic transformation of the egg. A new model is proposed here for integration of chromatin fragments into host chromosomes. It is also proposed that heterochromatin may be involved in the process of gene transfer, and in the phenomena of meiotic drive associated with gene transfer.It is suggested that this discovery throws new light on the phenomenon of graft-hybridization. In spite of many reports to the contrary, graft-hybrids have so far been explained only on the basis of their being chimaeras. A mechanism is suggested here by which they may result from genetic transformation.     

Biochemistry of terminal deoxynucleotidyltransferase (TdT): characterization and mechanism of inhibition of TdT by P1, P5-bis(5'-adenosyl) pentaphosphate

The catalysis of DNA synthesis by calf thymus terminal deoxynucleotidyltransferase (TdT) is strongly inhibited in the presence of Ap5A, while replicative DNA polymerases from mammalian, bacterial, and oncornaviral sources are totally insensitive to Ap5A addition. The Ap5A-mediated inhibition of TdT seems to occur via its interaction at both the substrate binding and primer binding domains as judged by classical competitive inhibition plots with respect to both substrate deoxynucleoside triphosphate (dNTP) and DNA primer and inhibition of ultraviolet light mediated cross-linking of substrate dNTP and oligomeric DNA primer to their respective binding sites. Further kinetic analyses of Ap5A inhibition revealed that the dissociation constant of the Ap5A-enzyme complex, with either substrate binding or primer binding domain participating in the complex formation, is approximately 6 times higher (Ki = 1.5 microM) compared to the dissociation constant (Ki = 0.25 microM) of the Ap5A-TdT complex when both domains are available for binding. In order to study the binding stoichiometry of Ap5A to TdT, an oxidized derivative of Ap5A, which exhibited identical inhibitory properties as its parent compound, was employed. The oxidation product of Ap5A, presumably a tetraaldehyde derivative, binds irreversibly to TdT when the inhibitor-enzyme complex is subjected to borohydride reduction. The presence of aldehyde groups in the oxidized Ap5A appeared essential for inhibitory activity since its reduction to alcohol via borohydride reduction or its linkage to free amino acids prior to use as an inhibitor rendered it completely ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)     

Studies on soil fungistasis: Effect of certain physical and biological factors

Summary The effect of different physical and biological factors like soil sterilization, incubation period of soil, spore age, amendment of certain fungal species and their metabolites on soil fungistasis has been investigated.Different degree of sterilization affected the fugistasis differently. Soil heating above 80°C completely annulled the fungistasis. No fungistasis was recorded in soil samples steamed for 15 mts in an autoclave.Incubation of soil samples to longer duration resulted in increased fungistasis. Maximum fungistatic value was noted in samples incubated for 15 days at 25±1°C.Spore age also played important role in fungistasis. A positive relation was noted in the spore age and fungistasis upto 30 days of age and thereafter the increase in fungistasis was not well marked.Varying inhibitory effect was noted on the spore germination of the test fungi in relation to amendment of certain fungi individually and in different combinations to the soil.Aspergillus flavus alone and in combination ofAspergillus niger proved most inhibitory. The filtrate of the different fungi also induced fungistasis in soil. In this case alsoA. flavus was most effective.     

Effect of Centchroman administration in normospermic & oligospermic individuals

The effect of Centchroman, 3,4-trans-2,2-dimethyl-3-phenyl-4-para-(beta -pyrrolidinoethocy)-phenyl-7-methorychroman, administration was investigated in normospermic and oligospermic subjects. 3 normal volunteers, aged 32-40 years, were treated with increasing doses (30, 60, and 120 mg/day, each dose for 2 weeks). The sperm count was decreased in 1 volunteer but the percentages of nonmotile and abnormal spermatozoa were increased in all 3. There was no change in plasma testosterone and urinary 17-ketosteroid (17-KS) levels but the 17-ketogenic steroids (17-KGSs) were decreased in all of them. 3 out of 5 oligospermic subjects, aged 24-35 years, who received 30 mg/day for 6 weeks revealed increased sperm counts. Plasma testosterone levels were decreased in 4, urinary 17-KGSs were decreased in 2, and 17-KSs were decreased in 1 subject. Acid phosphatase, fructose, sialic acid and glycerylphosphoryl choline levels in semen, and serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, and urea in blood were not markedly altered in either group.