Double-minute chromatin bodies in HL-60 leukemia cells sensitive and resistant to differentiation inducing agents

We studied the chromosome characteristics of HL-60 promyelocytic leukemia cells sensitive and resistant to differentiation inducing agents (DI). The karyotypic analysis of sensitive (HL-60 S) and resistant (HL-60 R) cells revealed the presence of identical chromosome abnormalities such as loss of chromosomes 5, 9, 10, 14, 16, 17 and X; and gain of chromosome 18. HL-60 S and HL-60 R cells also share five common markers. The difference between the two cell lines consisted essentially of the loss of an unidentifiable chromosome segment in the HL-60 R cell line. In addition, the two sublines showed marked differences in the content of double-minute chromatin bodies (DM), which were abundant in HL-60 S but rarely found in HL-60 R cells. Contrary to a previous report by others, there was no evidence of chromosome rearrangement of the DM as homogeneously stained regions (HSR) or abnormally banding regions (ABR) in the resistant HL-60 R cells. The presence of DM as an expression of gene amplification may be of relevance in the determination of susceptibility of HL-60 cells to DI.     

Comparative organic growth factor requirements of nine Candida species

Nine Candida species isolated from fleshy fruits have been examined for their organic growth factor requirements. Complete or partial deficiencies for thiamine, biotin, pyridoxine, inositol, pantothenic acid, ascorbic acid and xanthine have been reported in C. catenuclta, C. curiosa, C. curvata, C. humicola, C. rhagii, C. steatolytica and C. tropicalis. Only two species, namely, C. fragicola and C. ishiwadea were prototrophic for the growth factors. Concentrations of essential growth factors higher than the optimum have been found inhibitory for the growth of yeasts.     

Metabolic Syndrome Is Associated with Increased Oxo-Nitrative Stress and Asthma-Like Changes in Lungs

Epidemiological studies have shown an increased obesity-related risk of asthma. In support, obese mice develop airway hyperresponsiveness (AHR). However, it remains unclear whether the increased risk is a consequence of obesity, adipogenic diet, or the metabolic syndrome (MetS). Altered L-arginine and nitric oxide (NO) metabolism is a common feature between asthma and metabolic syndrome that appears independent of body mass. Increased asthma risk resulting from such metabolic changes would have important consequences in global health. Since high-sugar diets can induce MetS, without necessarily causing obesity, studies of their effect on arginine/NO metabolism and airway function could clarify this aspect. We investigated whether normal-weight mice with MetS, due to high-fructose diet, had dysfunctional arginine/NO metabolism and features of asthma. Mice were fed chow-diet, high-fat-diet, or high-fructose-diet for 18 weeks. Only the high-fat-diet group developed obesity or adiposity. Hyperinsulinemia, hyperglycaemia, and hyperlipidaemia were common to both high-fat-diet and high-fructose-diet groups and the high-fructose-diet group additionally developed hypertension. At 18 weeks, airway hyperresponsiveness (AHR) could be seen in obese high-fat-diet mice as well as non-obese high-fructose-diet mice, when compared to standard chow-diet mice. No inflammatory cell infiltrate or goblet cell metaplasia was seen in either high-fat-diet or high-fructose-diet mice. Exhaled NO was reduced in both these groups. This reduction in exhaled NO correlated with reduced arginine bioavailability in lungs. In summary, mice with normal weight but metabolic obesity show reduced arginine bioavailability, reduced NO production, and asthma-like features. Reduced NO related bronchodilation and increased oxo-nitrosative stress may contribute to the pathogenesis.     

Coping with ethnicity in South Asia: Bangladesh,Punjab and Kashmir compared

In the anthropological and sociological studies of India the terms ‘tribe’ and ‘caste’, have been in use for almost two hundred years. The related notions of ‘tribalism’ and ‘casteism’ were brought in to replace a static (structural) by a dynamic (organizational, processual) approach. Since the 1970s, ‘ethnic group’ and ‘ethnicity’ have gained currency. After defining the terms, three cases of ethnicity are examined, namely East Bengali Muslim, Punjabi Sikh and Kashmiri Muslim. It is argued that, while the first is a success story, the second seems more like a retreat at present, and the third is at best nascent. The reasons for this difference are explored. Ethnicity, it is argued, is not only characterization of identity, but also a set of strategies to establish a new state. This objective is opposed by competing ethnic groups and the existing state. Ethnic movements therefore involve violence and their outcome is dependent upon a variety of factors and therefore contingent.     

Release of 12 Adipokines by Adipose Tissue,Nonfat Cells,and Fat Cells From Obese Women

The relative release in vitro of endothelin‐1, zinc‐α2‐glycoprotein (ZAG), lipocalin‐2, CD14, RANTES (regulated on activation, normal T cell expressed and secreted protein), lipoprotein lipase (LPL), osteoprotegerin (OPG), fatty acid–binding protein 4 (FABP‐4), visfatin/PBEF/Nampt, glutathione peroxidase‐3 (GPX‐3), intracellular cell adhesion molecule 1 (ICAM‐1), and amyloid A was examined using explants of human adipose tissue as well as the nonfat cell fractions and adipocytes from obese women. Over a 48‐h incubation the majority of the release of LPL was by fat cells whereas that of lipocalin‐2, RANTES, and ICAM‐1 was by the nonfat cells present in human adipose tissue. In contrast appreciable amounts of OPG, amyloid A, ZAG, FABP‐4, GPX‐3, CD14, and visfatin/PBEF/Nampt were released by both fat cells and nonfat cells. There was an excellent correlation (r = 0.75) between the ratios of adipokine release by fat cells to nonfat cells over 48 h and the ratio of their mRNAs in fat cells to nonfat cells at the start of the incubation. The total release of ZAG, OPG, RANTES, and amyloid A by incubated adipose tissue explants from women with a fat mass of 65 kg was not different from that by women with a fat mass of 29 kg. In contrast that of ICAM‐1, FABP‐4, GPX‐3, visfatin/PBEF/Nampt, CD14, lipocalin‐2, LP, and endothelin‐1 was significantly greater in tissue from women with a total fat mass of 65 kg.     

Structural Characterization of CalS8, a TDP-α-d-Glucose Dehydrogenase Involved in Calicheamicin Aminodideoxypentose Biosynthesis

Classical UDP-glucose 6-dehydrogenases (UGDHs; EC 1.1.1.22) catalyze the conversion of UDP-α-d-glucose (UDP-Glc) to the key metabolic precursor UDP-α-d-glucuronic acid (UDP-GlcA) and display specificity for UDP-Glc. The fundamental biochemical and structural study of the UGDH homolog CalS8 encoded by the calicheamicin biosynthetic gene is reported and represents one of the first studies of a UGDH homolog involved in secondary metabolism. The corresponding biochemical characterization of CalS8 reveals CalS8 as one of the first characterized base-permissive UGDH homologs with a >15-fold preference for TDP-Glc over UDP-Glc. The corresponding structure elucidations of apo-CalS8 and the CalS8·substrate·cofactor ternary complex (at 2.47 and 1.95 Å resolution, respectively) highlight a notably high degree of conservation between CalS8 and classical UGDHs where structural divergence within the intersubunit loop structure likely contributes to the CalS8 base permissivity. As such, this study begins to provide a putative blueprint for base specificity among sugar nucleotide-dependent dehydrogenases and, in conjunction with prior studies on the base specificity of the calicheamicin aminopentosyltransferase CalG4, provides growing support for the calicheamicin aminopentose pathway as a TDP-sugar-dependent process.