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Background: Cytotoxic regimens used in induction treatments for acute myeloid leukemia (AML) almost always include standard or high-dose cytarabine (Ara-C). During or soon after induction therapy, leukemic patients frequently develop gastroenteric complications, characterized by abdominal pain and diarrhea. The association ofthese symptoms with f and melena is typical ofnecrotizing enterocolitis (NE), a life-threathening condition that can be documented by ultrasound abdominal scan. Patients and methods: We analyzed retrospectively the clinical course of169 adult patients with AML treated by standard dose Ara-C-containing induction regimens, either by continuous venous infusion (group 1) or subcutaneous injection (group 2). Ultrasonography was employed as early diagnostic tool in a majority ofpatients with gastroenteric complications. Bowel wall thickening was accurately measured and used to confirm the diagnosis of necrotizing enterocolitis. Results: In the first group of 115 patients (median age, 51 years), gastroenteric complications were observed in 55 patients (48%), and 10 patients (9%) received diagnosis ofNE, which was fatal in four. Patients with NE had a median age older than that of patients without gastroenteric symptoms, and a more prolonged neutropenia. In the second group of54 patients (median age, 60 years), gastroenteric events were observed in 14 patients (26%), and no case of NE was recorded. Conclusions: This retrospective analysis shows that NE is a serious complication occurring mainly in patients treated by Ara-C administered as continuous i.v. infusion. The Hematology Journal (2003) 4, 346–350. doi:10.1038/sj.thj.6200304

We investigated bone marrow (BM) and circulating (PB) hematopoietic progenitor cells in 37 normal donors and in 25 patients 1 to 8 years after successful allogeneic bone marrow transplant. At the time of testing, transplanted patients had normal blood counts and bone marrow cellularity. By flow cytometry, BM CD34+ cells were found to be three- to four-fold decreased in transplanted patients compared to normal donors, while the number of PB CD34+ cells was the same as in normal donors. Using a methylcellulose colony assay, primary BM colony-forming cells (CFU-GM) were decreased 2.1-fold, whereas PB CFU-GM were only marginally decreased. In a long-term culture initiating cell (LTC-IC) assay, an eight-fold decrease of early progenitor cells was observed in the marrow of transplanted patients compared to normal donors, and a five-fold decrease was documented in peripheral blood. We found that the BM LTC-IC cell number correlated with concurrently determined BM CD34+ cells and committed progenitor cell number (measured as CFU-GM) and with PB LTC-IC number, but not with PB CFU-GM and CD34+ cells. We conclude that marrow and circulating early stem cell compartments, as measured by the LTC-IC assay, are greatly and permanently depressed following bone marrow transplant. The correlation between BM and PB LTC-IC indicates that the enumeration of circulating LTC-IC can be used as a measure of the stem cell compartment in the bone marrow after transplant. It seems that the deficiency of the most immature progenitor cells persists forever after successful bone marrow transplant; this means that a complete hematopoietic reconstitution can be sustained by a reduced stem cell pool.

Although it has been determined that gambling is a popular activity amongst the young, there seems to be a lack of studies examining developmental differences in children's gambling behavior. This study examines developmental differences in children's blackjack gambling behavior. One hundred and four students (51 males; 53 females) from grades 4, 6, and 8 completed a questionnaire examining their gambling behavior in general and individually played a computerized blackjack game with the following data being recorded: percentage of accuracy, amounts of money bet, gross winnings, percentage of wins, number of hands played, and end balance. Findings revealed few developmental differences in prevalence and frequency of gambling behavior and performance on a blackjack task. Males were found to wager greater amounts of money and have larger gross winnings than females on the blackjack task. Furthermore, males were more likely to view gambling as involving both large amounts of skill and luck, thus suggesting an illusion of control for gambling activities. The results are discussed from a cognitive developmental perspective.

A recombinant Saccharomyces cerevisiae, expressing and secreting rice alpha-amylase, converts starch to ethanol. The rice alpha-amylase gene (OS103) was placed under the transcriptional control of the promoter from a newly described Pichia pastoris alcohol oxidase genomic clone. The nucleotide sequences of ZZA1 and other methanol-regulated promoters were analyzed. A highly conserved sequence (TTG-N3-GCTTCCAA-N5-TGGT) was found in the 5' flanking regions of alcohol oxidase, methanol oxidase, and dihydroxyacetone synthase genes in Pichia pastoris, Hansenula polymorpha, and Candida boidinii S2. The yeast strain containing the ZZA1-OS103 fusion secreted biologically active enzyme into the culture media while fermenting soluble starch.

We have cloned and functionally expressed a tyrosinase gene from Streptomyces antibioticus in Escherichia coli under the control of an inducible bacteriophage T7 promoter. Recombinant E. coli cells containing the induced tyrosinase gene produced melanin pigments on agar plates and in liquid culture when supplemented with copper and tyrosine. The expression of an additional open reading frame from the mel gene locus of S. antibioticus was required for high-level melanin production in E. coli. Our results also show that it is possible to screen other classes of precursor compounds for incorporation into melanin pigments with unique colors and other biochemical features. In addition, it may be possible to screen for enhanced melanin production in the absence of added precursors to identify overproducing mutants in the amino acid biosynthetic pathways of E. coli. The ability to screen for a melanin phenotype in recombinant E. coli provides new opportunities for production of novel melanins and for protein engineering of tyrosinases with altered catalytic properties.

Juvenile hormone (JH) treatment coordinately stimulated the dose-dependent synthesis of vitellogenin and endoplasmic reticulum (ER) membrane phospholipids in fat body cells from allatectomized adult females ofLeucophaea maderae. Animals were pulse-labeled in vivo with [32P] to simultaneously measure the rates of synthesis of the phosphorylated subunits of vitellogenin and the structural phospholipids of the ER membranes. Phospholipid synthesis in ER membranes from nontarget tissues for JH such as thoracic muscle, midgut, and larval fat body was unresponsive to hormone treatment. The proliferation of ER in response to JH treatment was thus restricted to tissue that was competent to synthesize vitellogenin.Primary and secondary vitellogenin induction was measured in allatectomized adult females treated 12 days apart with JH-III. The time-course of the primary response for vitellogenin and ER phospholipid synthesis was characterized by a 24 h latent period, a rapid increase to a maximum at 72 h, and then a gradual decline. During secondary induction, vitellogenin accumulated in the hemolymph nearly twice as fast as before and peaked at a concentration of 38 μg/μl. This vitellogenin titer was approximately two-fold higher than that found at the height of the primary response. During both primary and secondary stimulation with JH, ER phospholipid synthesis, as measured by [14C]choline incorporation into microsomal phosphatidylcholine, was stimulated five-fold over the untreated control animals. The amplified production of vitellogenin during the secondary response was associated with a 24 h-earlier peak of ER phospholipid synthesis in the fat body.

Targeting a Herbicide–Resistant Enzyme from Escherichia Coli to Chloroplasts of Higher Plants

A Daucus carota cell line selected as resistant to N-(phosphonomethyl)-glycine (glyphosate) was found to have increased levels of 5-enolpyruvylshikimic acid-3-phosphate synthase (EPSPS) activity of 5.5 times over wild-type carrot and an EPSPS protein level increase of 8.7 times as confirmed by Western hybridization analysis. Southern blot hybridization using a petunia EPSPS probe showed increases in the number of copies of EPSPS genes in the glyphosate-resistant line which correlated with the higher levels of the EPSPS enzyme. The mechanism of resistance to glyphosate is therefore due to amplification of the EPSPS gene. To examine the stability of the amplified genes, cloned lines selected as doubly resistant to Dl-5-methyltryptophan (5MT) and azetidine-2-carboxylate (A2C) were fused with the amplified EPSPS glyphosate-resistant cell line. Somatic hybrids expressed resistances to 5MT in a semidominant fashion while A2C and glyphosate resistance was expressed as dominant, or semi-dominant traits, in a line-specific manner. The hybrid lines possessed additive chromosome numbers of the parental lines used and no double minute chromosomes were observed. The glyphosate-resistant parental line and most somatic hybrids retained the amplified levels of EPSPS in the absence of selection pressure over a 3-year period.