Dolichol synthesis in liver slices of streptozotocin diabetic rats

The rate of dolichol synthesis in normal and diabetic liver slices in the presence or absence of insulin was investigated with radiolabeled acetate and mevalonate as substrates. Cholesterol and dolichol syntheses were found low in diabetic rat liver slices when incubated either with 1-14C-acetate or 2-3H-mevalonate. In the presence of insulin, cholesterol and dolichol synthesis in diabetic rat liver slices returned to normal in nine hours when incubated with 1-14C-acetate; however, with 2-3H-mevalonate, synthesis of cholesterol and dolichol normalized in about three hours. These studies show that dolichol synthesis in rat liver slices is dependent on insulin.     

Zinc Deficiency and Anther Development in Maize

With the onset of male reproductive phase at 28 days, zinc waswithdrawn from fifty percent of maize (Zea mays L. cv. Ganga2) plants grown in refined sand at 0.13 mg Zn liter^–1.Plants from which zinc was withdrawn developed zinc deficiencysymptoms in young leaves after 38 days and were low in tissuezinc. Their tassel formation and pollen development was retarded.Anthers failed to develop beyond freshly liberated young pollengrain stage and vessels were formed in place of sporogenoustissue in sixty percent anthers of the younger of the two florets.Anthers from these plants showed low zinc concentration andstimulated specific activities of catalase, peroxidase, ribonucleaseand acid phosphatase. On resuming normal zinc (0.13 mg Zn liter^–1) through rootsto the plants from which it was withdrawn for 17 days, vegetativegrowth was partially renewed and short axillary buds were formedbut the development of anthers remained retarded. (Received April 11, 1986; Accepted October 15, 1986)     

Plant-water relations in wheat as influenced by root pruning

Summary A greenhouse study in which 24, 54 and 71 per cent roots of wheat (Triticum aestivum L.) were pruned on the 73rd day from the date of planting (anthesis stage) showed that during a 7-day period following root pruning, total transpiration and leaf water potential were significantly lower (P=0.05) and the stomatal resistance was significantly higher (P=0.05) where 54 and 71 per cent roots were pruned, as compared to no root pruning or 24 per cent root pruning. The leaf relative water content, however, showed no significant differences. Thus about one-fourth root sytem could be reduced without adversely affecting the plant-water status.     

Cytological studies on six cyprinid fishes

The chromosome complements of six cyprinid fishes were studied, using the routine air-drying Giemsa staining technique. The diploid chromosome number recorded is 2n = 50 (8m+18sm+14st+10t) with NF = 90 in Aspidoparia morar, 2n = 50 (8m+12sm+12st+18t) with NF = 82 in Crossocheilus latius latius, 2n = 50 (6m+12sm–16st+16t) with NF = 90 in Labeo pangusia, 2n = 70 (16m+6sm+16st–32t) with NF = 108 in Perilampus atpar, 2n = 48 (4m+6st+38t) with NF = 58 in Puntius chrysopterus and 2n = 50 (2m+2sm+4st+42t) with NF = 58 in P. tetrarupagus. Sex chromosomes are not identifiable in any of these species. A pair of marker chromosomes has been observed in all species excepting A. morar.     

On species of genus Lepadella (Eurotatoria:Monogononta:Colurellidae) from North-Eastern India,with remarks on Indian taxa

Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India. Two of these species are new records from this country and six are new reports from N.E. region. Comments are also made on the status and distribution of various Indian taxa.     

Burkitt-type lymphoma. Diagnosis by fine needle aspiration cytology

Forty cases of lymphoma were categorized as Burkitt-type lymphoma in a study of fine needle aspiration (FNA) smears. These constituted 14.3% of all cases of non-Hodgkin's lymphoma diagnosed between 1974 and 1982. The median age was 22 years in these cases, 81.8% of which had extranodal tumors. The majority of the cells in the smears (59.8% +/- 8.32%) were in the 11 micron to 15 micron size range and 60.3% +/- 10.3% had noncleaved nuclei. An average 71% of the cells contained cytoplasmic and/or nuclear vacuolizations. Nonneoplastic macrophages were present in the smears in 87.5% of the cases. A study of paraffin-embedded sections in 17 cases revealed the characteristic "starry-sky" appearance in 11; in 5 it was not clearly appreciated and in 1 the nonneoplastic macrophages were absent. FNA cytology was found to be quite reliable for arriving at a diagnosis of Burkitt-type lymphoma. More than 50% of the cases were managed without resort to subsequent surgical biopsy. Exploratory laparotomy was avoided in 69% of the cases having abdominal tumors.     

Temperature-Light Intensity Effect on the Antagonism of Species of Cladosporium to Melampsora larici-populina on Cultivars of Populus X euramericana (Dode) Guinier

The antagonistic and colonistic effect of post-inoculation temperature and light intensity was investigated in a factorial experiment involving four Cladosporium spp., three poplar cultivars, two levels of temperature and light intensity, anda race of Melampsora larici-populina. The species of Cladosporium were more antagonistic to uredinial production on the inoculated leaf discs of the cultivars when these were incubated in high temperature – high light intensity than in any other regime. Whilst colonisation of the uredinia was usually minimal in discs incubated on the high temperature – high light intensity regime, the condition of incubation favouring maximum colonisation varied with the cultivar and the species of Cladosporium employed. All the major factors and most of their two-, three- and four-way interactions were significant determinants of variation in both antagonism to uredinial production and in colonisation of the uredinia produced. The validity ofextrapolation from such experiments to the field environment is discussed.     

Reaction of nitric oxide with heme proteins and model compounds of hemoglobin

Rates for the reaction of nitric oxide with several ferric heme proteins and model compounds have been measured. The NO combination rates are markedly affected by the presence or absence of distal histidine. Elephant myoglobin in which the E7 distal histidine has been replaced by glutamine reacts with NO 500-1000 times faster than do the native hemoglobins or myoglobins. By contrast, there is no difference in the CO combination rate constants of sperm whale and elephant myoglobins. Studies on ferric model compounds for the R and T states of hemoglobin indicate that their NO combination rate constants are similar to those observed for the combination of CO with the corresponding ferro derivatives. The last observation suggests that the presence of an axial water molecule at the ligand binding site of ferric hemoglobin A prevents it from exhibiting significant cooperativity in its reactions with NO.     

Age-dependent regulation of glucocorticoid receptors in the liver of male rats

Specific binding of [3H]dexamethasone to cytosol and the activation of bound hormone-receptor complexes were studied in the liver of immature (3 weeks old) and mature (26 weeks old) Long-Evans male rats. The concentration of specific binding sites was significantly higher (33%) in the liver of immature rats as compared to mature, while dissociation constants (Kd) remain unaltered at both ages. Heat activation (for 45 min at 25 degrees C) significantly enhances the binding of [3H]dexamethasone-receptor complexes to DNA-cellulose and purified nuclei at both the ages, with a greater magnitude in mature rats. Cross mixing experiments (i.e., binding of activated cytosol from mature rats to nuclei of immature and vice-versa) show receptor specificity. Ca2+ activation (20 mM Ca2+ for 45 min at 0 degree C) also enhances the nuclear and DNA-cellulose binding at both the ages, but to a similar extent. Differences in the number of specific binding sites and some of the physiochemical properties of glucocorticoid receptors presented here between immature and mature rats may underlie the functional changes in tissue response with age.