The development of tumor cell drug resistance is a major obstacle which often leads to failure of cancer chemotherapy. Therefore, reversing the cell drug resistance would have important implications in cancer treatment. We have developed a cisplatin-resistant mouse tumor cell line from the radiation induced fibrosarcoma (RIF-1) parental line; this line is named RIF/ptr1 versus the parental line...

Trypanosomatid parasitic protozoans of the genus Leishmania are autotrophic for both folate and unconjugated pteridines. Leishmania salvage these metabolites from their mammalian hosts and insect vectors through multiple transporters. Within the parasite, folates are reduced by a bifunctional DHFR (dihydrofolate reductase)-TS (thymidylate synthase) and by a novel PTR1 (pteridine reductase 1), w...

The protozoan Trypanosoma brucei has a functional pteridine reductase (TbPTR1), an NADPH-dependent short-chain reductase that participates in the salvage of pterins, which are essential for parasite growth. PTR1 displays broad-spectrum activity with pterins and folates, provides a metabolic bypass for inhibition of the trypanosomatid dihydrofolate reductase and therefore compromises the use of ...

The hyperthermophilic archaeon Methanococcus jannaschii encodes two putative transcription regulators, Ptr1 and Ptr2, that are members of the Lrp/AsnC family of bacterial transcription regulators. In contrast, this archaeon's RNA polymerase and core transcription factors are of eukaryotic type. Using the M. jannaschii high-temperature in vitro transcription system, we show that Ptr2 is a potent...

A critical step in the infectious cycle of Leishmania is the differentiation of parasites within the sand fly vector to the highly infective metacyclic promastigote stage. Here, we establish tetrahydrobiopterin (H4B) levels as an important factor controlling the extent of metacyclogenesis. H4B levels decline substantially during normal development, and genetic or nutritional manipulations showe...

Pistacia integerrima Stew ex Brandis is a valued medicinal plant used for curing various diseases such as diarrhea, fever, liver disorder, pain, asthma, and inflammation. The aim of this study was the isolation bioactive leishmanicidal agents from methanolic extract. extract led to flavonoids 3,5,7,4/-tetrahydroxy-flavanone (1). isolated compound 1 were tested antileishmanial effect. showed per...

Abstract Adrenomedullin (ADM) is an evolutionarily conserved multi-functional peptide hormone in mammalian species. The implantation sites of conceptuses (embryo/fetus and its extra-embryonic membranes) pregnant Adm+/− female mice are abnormally spaced leading to fetal crowding, intrauterine growth restriction (IUGR) increases pregnancy loss. As litter-bearing species, pigs exhibit a high incid...