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L Mishra

Publications and source records attributed to L Mishra.

46 records · Page 3Linked to original sources

Transcription of cholera toxin operon in wild-type and mutant strains of Vibrio cholerae.

mRNA for cholera toxin (CT) was measured in wild-type, hypertoxinogenic, and hypotoxinogenic strains of the classical biotype. The amount of CT-specific mRNA was directly related to the amount of CT that the strains could produce. Estimates of the size of the mRNA for CT in individual experiments varied between approximately 900 and 1,100 nucleotides.

Cholera Toxin↗

Physical maps of varicella-zoster virus DNA derived with 11 restriction enzymes.

Varicella-zoster virus DNA was digested with 11 restriction endonucleases, and the resulting fragments were separated on agarose gels. Terminal fragments were identified by lambda exonuclease digestion. Physical maps were then constructed using a combination of double restriction enzyme digestion and hybridization to cloned BamHI fragments to place the remaining fragments in order.

Base Sequence↗

Interferon production by human cells in vitro.

The relative capacity of several types of human cells and tissue to produce interferon was studied. Types of cells and tissue included were fibroblasts from embryos, foreskins, and biopsied skins; amnion cells; peripheral leukocytes; established lymphoid cell lines; established heteroploid cell lines; and chorioamniotic membrane. When Newcastle disease virus was used as the inducer, fibroblasts and amnion cells produced more interferon per 10(6) cells than leukocytes, lymphoid cells, and heteroploid cells. Only minor variations in interferon-producing capacity were observed among fibroblasts from 36 persons. Culture passage level, cell concentration, and inducer were factors that significantly affected interferon production.

Adult↗

Expansion of hepatic and hematopoietic stem cells utilizing mouse embryonic liver explants.

Ex vivo embryonic liver explant culture is a novel and attractive approach to obtain abundant hepatic and hematopoietic stem cells. Gene therapy of autologous hepatic and hematopoietic stem cells represents an alternative therapeutic approach to liver transplantation for genetic and metabolic disorders. In this study we characterize the growth and differentiation of hepatic stem cells utilizing embryonic liver cultures. Day 9.5 liver buds are microdissected and cultured under specific conditions. Modulation of growth conditions by addition of hepatocyte growth factor, Flt-3 ligand, and stem cell factor leads to enrichment of hepatic progenitor cells in embryonic liver explants. Under these conditions, we also demonstrate the role of a novel marker PRAJA-1 to identify hepatic stem cells and transitional hepatocytes. Utilization of dexamethasone enhanced pseudolobule formation with increased hepatocytic and biliary differentiation. Transforming growth factor-beta leads to enrichment of biliary cells in the culture. Gut formation is enhanced in the presence of interleukin-3 and blood formation by increasing the mesodermal tissue in these cultures. We also show increased retroviral-mediated expression of the green fluorescent protein expression in the expanded hepatic and hematopoietic stem cells under different culture conditions. Thus, the embryonic liver explant culture is an attractive source for hepatic progenitors and is a possible step towards generating nontumorigenic immortalized hepatocytes with possible transplantation applications.

Animals↗

Sequences homologous to BAV component of HL23V in baboon tissues.

The BAV component of HL23V virus (HL23V-BAB) hybridized to DNA from different Baboon tissues and appears to be an endogenous Baboon virus. Competition hybridization studies show that HL23V-BAB is closely related to viruses isolated from various Baboon species: P. hamadrys, P. papio, and P. cynocephalus. Competition hybridization studies also show that normal Baboon tissues contain more copies of proviral DNA than cells infected in vitro.

Animals↗