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.     

Factors influencing the sensitivity of two human bladder carcinoma cell lines to cis-diamminedichloroplatinum(II)

A two-fold difference in sensitivity to cis-diamminedichloroplatinum(II) (cisplatin), as judged by colony forming assays, has been demonstrated in two human bladder carcinoma continuous cell lines. Approximately twice as many DNA-DNA interstrand cross-links (ISL) and a 2-fold greater inhibition of DNA synthesis occurred in the more sensitive T24 cell line than in the RT112 cell line after exposure to the same concentrations of cisplatin. Equitoxic concentrations of cisplatin resulted in similar extents of ISL and inhibition of DNA synthesis in both cell lines. Although drug uptake was identical, twice as much cisplatin was bound to the DNA of T24 cells than RT112 cells. However after equitoxic concentrations of cisplatin the DNA from both cell lines was platinated to a similar extent. In addition, levels of glutathione (GSH), glutathione reductase (GR) and total glutathione-S-transferases (GST) were higher in the less sensitive RT112 cell line.     

Fluorinated carbohydrates as potential plasma membrane modifiers and inhibitors. Synthesis of 2-acetamido-2,6-dideoxy-6-fluoro-D-galactose

Reaction of benzyl 2-acetamido-3,4-di-O-benzyl-2-deoxy-6-O-mesyl-alpha-D-galactopyran oside with cesium floride gave benzyl 2-acetamido-3,6-anhydro-4-O-benzyl-2-deoxy-alpha-D-galactopyranoside instead of the desired 6-fluoro derivative. Acetonation of benzyl 2-acetamido-2-deoxy-6-O-mesyl-alpha-D-galactopyranoside gave the corresponding 3,4-O-isopropylidene derivative. The 6-O-mesyl group was displaced by fluorine with cesium fluoride in boiling 1,2-ethanediol, and hydrolysis and subsequent N-acetylation gave the target compound. In another procedure, treatment of 2-acetamido-1,3,4-tri-O-acetyl-2-deoxy-alpha-D-galactose with N-(diethylamino)sulfur trifluoride gave 2-acetamido-1,3,4-tri-O-acetyl-2,6-dideoxy-6-fluoro-D-galactose which, on acid hydrolysis followed by N-acetylation, gave 2-acetamido-2,6-dideoxy-6-fluoro-D-galactose.     

Effect of phosphate supplementation on oxygen delivery at high altitude

In the present communication, effect of low doses of phosphate supplementation on short-term high altitude adaptation has been examined. Studies were carried out in 36 healthy, male, sea-level residents divided in a double blind fashion into drug and placebo treated groups. 3.2 mmol of phosphate were given orally to each subject of the drug treated group once a day for 4 days on arrival at an altitude of 3,500 m. Sequential studies were done in the subjects in both groups on the 3rd, 7th, 14th and 21st day of their altitude stay. Haemoglobin, haematocrit, erythrocyte and reticulocyte counts increased to the similar extent in both groups. Blood pH, pO₂ and adenosine tri-phosphate (ATP) did not differ between the two groups. On 3rd day of the altitude stay, inorganic phosphate and 2,3-diphosphoglycerate (2,3 DPG) levels in the drug treated group increased significantly as compared to the placebo group. No significant difference in inorganic phosphate and 2,3 DPG was observed later on in the two groups. Psychological and clinical tests also indicated that the drug treated subjects felt better as compared to the placebo treated subjects. The present study suggests that low doses of phosphate increases circulating 2,3-DPG concentration which in turn brings about beneficial effect towards short term high altitude adaptation.