Browsing by Issue Date, starting with "1981"

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The prophylactic action of (-)-Epicatechin against alloxan induced diabetes in rats
(1981) B.K. Chakravarthy; S. Gupta; S.S. Gambhir; K.D. Gode
(-)-Epicatechin (1) was isolated from the bark of an Indian medicinal plant Pterocarpus marsupium Roxb. the water extract of which is used as an antidiabetic drug (2). (-)-Epicatechin administration to albino rats of either sex in doses of 30 mg/kg (i.p.) for two days prior to alloxan (150 mg/kg i.p.) administration, and continued for next 24 hours was able to protect the animals against the diabetogenic actions of alloxan. The protection by (-)-epicatechin may be due to scavenging of the deleterious and highly reactive hydroxyl radical which is generated by alloxan. © 1981.
Protective effects of certain environmental factors on the toxicity of zinc, mercury, and methylmercury to Chlorella vulgaris
(1981) L.C. Rai; J.P. Gaur; H.D. Kumar
The specific growth rate and final yield of Chlorella vulgaris treated with zinc, mercury, and methylmercury declined with increase in metal concentration. Methylmercury was most toxic and at 1 × 10-3 mg/liter concentration it reduced survival by about 50%. Approximately 50% mortality occurred at 25 and 0.4 mg/liter concentration of zinc and mercury, respectively. The total chlorophyll content decreased and the carotenoids/chlorophyll ratio increased with increase in heavy metal concentration. Of the various factors investigated, pH, phosphate, and calcium produced a highly significant (P < 0.001) effect on metal toxicities, and magnesium produced a less significant effect (P < 0.1). The present study suggests that alkaline and hard eutrophic waters might help protect freshwater organisms against heavy metal toxicity. © 1981.
Frequency dependence of the surface states at the N-type Si-SiO2 interface
(Springer India, 1981) R.J. Singh; R.S. Srivastava
The response of the surface states at the n-type Si-SiO2 interface to the different a.c. signal frequencies has been studied. The response values have been computed from both the measured capacitance voltage (C-V) and conductance-voltage (G-V) techniques. The results presented show that the frequency response of the effective density of states to different a.c. signal frequencies is proportional to the log of the applied frequencies. © 1981 Indian Academy of Sciences.
Morphine hyperthermia in rats: Role of neurochemical substances in the brain
(1981) U. Prakash; P.K. Dey
The central neurochemical mechanism underlying the hyperthermic effect of morphine has been investigated in rats. 200 μg morphine hydrochloride, when administered through cerebroventricular route at different seasonal air temperatures caused a rise in rectal temperature of rats. This hyperthermia was not affected by prior administration of antiserotonergic (pCPA, 5,6-DHT) or anticatecholaminergic (PBZ, 6-OHDA) drugs, as well as by PGE synthetase inhibitor, indomethacin. Similarly, cholinergic muscarinic or nicotine receptor blockers, such as atropine and pentolinium/D-tubocurarine, respectively, were ineffective in modifying it. In contrast, the depletion of acetylcholine in brain induced by pretreating the animals with hemicholinium profoundly delayed the hyperthermia, suggesting a central cholinergic involvement in morphine-induced hyperthermia in rats.
Staphylococcal myocarditis presenting with Stokes-Adams attacks
(1981) B.V. Agrawal; S.P. Verma; A. Sharma; P.N. Somani; P.K. Srivastava
[No abstract available]
Histiocytes in vaginal smears: As prognostic parameter in carcinoma of the uterine cervix
(1981) Saroj Gupta; Abha Rani; Y.N. Gupta; B. Sanyal; S. Khanna
Pretreatment vaginal smears of 251 patients with carcinoma of the cervix were counted for the percentage of histiocyte count in relation to benign squamous epithelial cells. No correlation was found between the percentage of histiocyte count and the age of the patient, clinical stage, cell type of squamous cell carcinoma, and clinical radiation response. Also a high histiocyte count is found to be unrelated to 5‐year survival, recurrence, metastasis, or death of these patients. The present study indicates that the histiocyte number appears to have no relationship with immediate or remote prognosis in patients with carcinoma of cervix uteri. Copyright © 1981 Wiley‐Liss, Inc., A Wiley Company
Genetic analysis of the het and nif genes in the blue-green alga Nostoc muscorum
(Springer-Verlag, 1981) R.K. Singh; H.N. Singh
Two multiply marked complementary strains namely Het+ Nif+ Str-R and Het- Nif- Ery-R MSO-R were constructed and crossed under conditions counterselective for the Het+ Nif+ Str-R parent and selective only for recombinants of Str-R and Ery-R or Str-R and MSO-R constitution. The results of the recombinant analysis with regard to the selected and unselected markers suggested that the Het- Nif- Ery-R MSO-R parent acted as a recipient and the Het+ Nif+ Str-R parent as donor of the genetic markers in the cross. The joint inheritance of Het+ and Nif+ unselected markers among the recombinants was found to occur more frequently than the inheritance of the Het+ or Nif+ markers alone. The observed joint inheritance of Het+ and Nif+ markers among the recombinants probably results from the inheritance of the regulatory gene(s) required for the activation of latent het and nif genes. This interpretation is fully supported by (a) the frequency distribution of unselected Het+ and Nif+ markers and (b) the reversion frequency of Het-Nif- strains to Het+ Nif+ prototrophy. Accordingly the apparent close genetic linkage of het and nif genes is not due to their organization in a single operon but to their common regulation by regulatory gene(s) of a positive control nature. The Het+ Nif+ wild type, mutant, revertant, and recombinant strains all appear similar in their NO3-repression of both heterocyst and nitrogenase. The Het+ Nif- and Het- Nif+ recominants also show similar NO3-repression of their heterocyst and nitrogenase respectively. The presence of only microaerobic acetylene reducing activity in Het- Nif+ recombinants clearly indicates the heterocyst to be an organ for protection of nitrogenase against oxygen toxicity. © 1981 Springer-Verlag.
Sarcomas of the breast: Homogenous or heterogenous?
(1981) Sushila Khanna; Saroj Gupta; N.N. Khanna
Eighteen cases of sarcomas of the breast are reported. Cases could be divided into two groups histogenetically. Group A, malignant cystosarcoma phylloides (14 cases); and Group B, pure sarcomas (4 cases). The malignant cystosarcoma phylloides occurred in the fourth decade, had longer duration of illness invariably followed by sudden increase in the size of the tumor, had a striking mucoid and slimy look grossly, and showed discernable epithelial elements histologically. In the event of their recurrence the ductal elements were not seen microscopically. Contrarily, Group B cases presented in the sixth decade were rapidly growing from the beginning, and grossly were fleshy and haemorrhagic. Microscopically these did not reveal any epithelial component. There was poor correlation between cytologic malignancy and the biologic behavior in Group A. Mode of treatment seems more important in determining the subsequent course of the disease. Simple mastectomy with follow‐up appears to be adequate in the majority of cases. Copyright © 1981 Wiley‐Liss, Inc., A Wiley Company
Synthesis and structural studies of mixed ligand (8-quinolinolato) (acetylacetonato) complexes of VO(IV), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)
(1981) R.C. Aggarwal; R.A. Rai; T.R. Rao
[No abstract available]
Some thoughts on the mechanism of acetal formation and related reactions: Extension of Baldwin's rules for ring closure
(1981) O.P. Reddy; S.M. Singh; R.Balaji Rao
Extension of Baldwin's rules for ring closure to dioxolane formation and related reactions has been attempted. A plausible mechanism has been arrived at on the basis of available literature evidence and earlier work reported from our laboratory. © 1981.
A report on the presence of trematode parasites in the brain ventricles of the teleost Channa punctatus (Bloch)
(1981) B.N. Joshi; A.G. Sathyanesan
[No abstract available]
On the geometry of vortex-lines in magnetofluid-flows
(Springer-Verlag, 1981) S.S. Gangwar; Ram Babu
[No abstract available]
Histological and histochemical study of the caudal neurosecretory system of the freshwater teleost Ompok bimaculatus (Bloch) with a note on its response to hypophysectomy and osmotic stress
(1981) S. Haider; A.C. Pandey
[No abstract available]
Response of reptilian gonad to melatonin
(1981) Chandana Haldar-Misra; J.P. Thapliyal
The effect of melatonin treatment on the weight and volume of gonads and accessory sex organs of sham-operated and pinealectomized lizards (Calotes versicolor) was examined during the different phases of the annual gonadal cycle of the animal. Melatonin injections to sham-operated lizards inhibited gonadal activity during the progressive (April-May), reproductive (June-July) and early regression (September-October) phases of the cycle, but had no effect on the atrophied gonad present during the inactive and early progressive phases. Pinealectomy increased the weight and volume of the gonads and accessory sex organs at all phases of the gonadal cycle. Melatonin treatment in pinealectomized lizards counteracted the effect of pinealectomy. It is concluded that melatonin is antigonadotropic in this species of tropical lizard. © 1981 S. Karger AG, Basel.
Effect of cadmium ion on the differentiation and micronutrient utilization in Nostoc calcicola
(1981) S.P. Singh; A.K. Pandey
[No abstract available]
INDUCTION OF POLLEN EMBRYOIDS IN SOLANUM TORVUM SWARTZ
(Indian Academy of Sciences, 1981) V.S. Jaiswal; Pratap Narayan
[No abstract available]
Non-random distribution of aberrations and identification with C- and G-bindings of the position of breakage points on muntjac chromosomes induced by mitomycin C, bromodeoxyridine and hydroxylamine
(1981) Pramila Gupta; T. Sharma
The analysis of chromosomes from muntjac after treatment of its lymphocyte cultures with 3 chemical mutagens having different base-pair affinities and modes of action, namely mitomycin C (MC), 5-bromodeoxyuridine (BUdR) and hydroxylamine hydrochloride (HA), with G- and C-band staining displayed non-random distribution of chemically specific damage points on them. The randomness of the involvement of each site on the chromosomes was examined by assuming an expected value calculated on the basis of its relative mitotic length. The observation revealed that a large fraction of MC-induced aberrations was preferentially located in the C-band positive constitutive heterochromatin, especially in the long "neck-like" centromeric region of the X-chromosome. On the chromosomal arms, the light G-bands were involved in aberrations either in proportion to or higher than that expected. When the cells were treated with BUdR, the dark G-bands on all the chromosomes of the complement were the preferred sites, displaying statistically significant higher numbers of aberrations. A singe "hot-spot" for induced damage on 1 mid-q was also recorded. HA induced a very high frequency of damage in the secondary constriction regions of the chromosome pairs 1, X and Y2, and the frequency was slightly lower than this in the centromeres of 1, 2 and X chromosomes. The observation of specific distribution of damage points induced by the 3 chemicals leads to the suggestion that, though the effect of a chemical on chromosome segments depends on several factors, each being partially responsible for the end result, it is perhaps primarily decided by the chemical's base-pair affinity and mode of action. A large variety of chemicals induce, in chromosomes, aberrations that are often distributed non-randomly. The non-random distribution of the chemically induced aberrations was noted even before the discovery of banding techniques, but with the use of conventional staining the identification of the exact location of induced break points, except for a few specific landmarks such as centromeres or secondary constrictions, was difficult and often unreliable too. Therefore, by using various banding techniques as a tool, a much more accurate assessment of the induced break points could be made. Several studies suggest that the involvement of specific chromosomes and/or chromosome segments are probably dependent upon the chemical used (Ayrand et al, 1976; Kaina, 1977; Kucerova and Polivkova, 1976; Morad et al., 1973; Morad and Zavahri, 1977; Reeves and Margoles, 1974). Meyne et. (1979) have suggested that, in addition to the nature of the chemicals used, the organization of chromosomes may also be responsible for the localized aberrations. To examine these points further, it was considered of interest to compare the extent of sensitivity of different chromosomal segments identified with banding techniques, after exposure to certain chemicals having different modes of action and base-pair affinities. In the present study, we compared the location of damage points on the chromosomes of the Indian barking deer Muntiacus muntjak, induced by 3 chemicals, namely (1) mitomycin C (MC), an antibiotic that acts by forming cross links with guanines between the complementary strands (Iyer and Szybalski, 1963), (ii) 5-bromodeoxyuridine (BUdR), a base analogue which is incorporated with concomitant thymine replacement into the DNA of mammalian cells (Djordjevic and Szybalski, 1960) and causes mutagenesis through a maispairing mechanism (Drake, 1970; Witkin and Parisi, 1974; Hutchinson and Stein, 1977; Rydberg, 1977), and (ii) hydroxylamine hydrochloride (HA), a reducing agent which reacts mainly with the cytosine moiety of the DNA by aminating only the C-4 atoms (Freese et al., 1961). © 1981.
A PLANE SYMMETRIC UNIVERSE FILLED WITH STIFF MATTER
(Indian Academy of Sciences, 1981) Abdussattar
[No abstract available]
Defence structure development in Rhizopus nigricans during mycoparasitism by Fusarium oxysporum F. sp. lycopersici
(Martinus Nijhoff/Dr. W. Junk Publishers, 1981) S.P. Pathak; Vijay Kumar; R.S. Dwivedi
The colony interaction and hyphal interference between F. oxysporum f. sp. lycopersici and R. nigricans were studied. Intermingling growth of both colonies was observed. Hyphal parasitism was characterized by coiling, penetration, ramification inside host, rupture of host hyphae and frequent chlamydospore formation. The host hyphae bulged out and deposited a 'wall like barrier'. The parasite penetrated the barrier and developed further. © 1981 Martinus Nijhoff/Dr. W. Junk Publishers.
Chronohaematological changes in the lizard Calotes versicolor after pinealectomy
(1981) C. Haldar; J.P. Thapliyal
[No abstract available]