292 research outputs found
Restoration of p16INK4A protein induces myogenic differentiation in RD rhabdomyosarcoma cells
p16INK4A (p16) tumour suppressor induces growth arrest by inhibiting function of cyclin-dependent kinase (CDK)4 and CDK6. Homozygous p16 gene deletion is frequent in primary rhabdomyosarcoma (RMS) cells as well as derived cell lines. To confirm the significance of p16 gene deletion in tumour biology of RMS, a temperature-sensitive p16 mutant (E119G) gene was retrovirally transfected into the human RMS cell line RD, which has homozygous gene deletion of p16 gene. Decrease from 40Β°C (restrictive) to 34Β°C (permissive) culture temperature reduced CDK6-associated kinase activity and induced G1 growth arrest. Moreover, RD-p16 cells cultured under permissive condition demonstrated differentiated morphology coupled with expressions of myogenin and myosin light chain. These suggest that deletion of p16 gene may not only facilitate growth but also inhibit the myogenic differentiation of RD RMS cells. Β© 1999 Cancer Research Campaig
Chemical characterization of oligosaccharides in the milk of six species of New and Old world monkeys
Human and great ape milks contain a diverse array of milk oligosaccharides, but little is known about the milk oligosaccharides of other primates, and how they differ among taxa. Neutral and acidic oligosaccharides were isolated from the milk of three species of Old World or catarrhine monkeys (Cercopithecidae: rhesus macaque (Macaca mulatta), toque macaque (Macaca sinica) and Hamadryas baboon (Papio hamadryas)) and three of New World or platyrrhine monkeys (Cebidae: tufted capuchin (Cebus apella) and Bolivian squirrel monkey (Saimiri boliviensis); Atelidae: mantled howler (Alouatta palliata)). The milks of these species contained 6β8% total sugar, most of which was lactose: the estimated ratio of oligosaccharides to lactose in Old World monkeys (1:4 to 1:6) was greater than in New World monkeys (1:12 to 1:23). The chemical structures of the oligosaccharides were determined mainly by 1H-NMR spectroscopy. Oligosaccharides containing the type II unit (Gal(Ξ²1-4)GlcNAc) were found in the milk of the rhesus macaque, toque macaque, Hamadryas baboon and tufted capuchin, but oligosaccharides containing the type I unit (Gal(Ξ²1-3)GlcNAc), which have been found in human and many great ape milks, were absent from the milk of all species studied. Oligosaccharides containing Lewis x (Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc) and 3-fucosyl lactose (3-FL, Gal(Ξ²1-4)[Fuc(Ξ±1-3)]Glc) were found in the milk of the three cercopithecid monkey species, while 2-fucosyl lactose (5'-FL, Fuc(Ξ±1-2)Gal(Ξ²1-4)Glc) was absent from all species studied. All of these milks contained acidic oligosaccharides that had N-acetylneuraminic acid as part of their structures, but did not contain oligosaccharides that had N-glycolylneuraminic acid, in contrast to the milk or colostrum of great apes which contain both types of acidic oligosaccharides. Two GalNAc-containing oligosaccharides, lactose 3β²-O-sulfate and lacto-N-novopentaose I (Gal(Ξ²1-3)[Gal(Ξ²1-4)GlcNAc(Ξ²1-6)]Gal(Ξ²1-4)Glc) were found only in the milk of rhesus macaque, hamadryas baboon and tufted capuchin, respectively. Further research is needed to determine the extent to which the milk oligosaccharide patterns observed among these taxa represent wider phylogenetic trends among primates and how much variation occurs among individuals or species
Variation in virulence in the rice blast fungus Magnaporthe grisea in SΓ£o Paulo State
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Chemical structures of oligosaccharides in milks of the American black bear (Ursus americanus americanus) and cheetah (Acinonyx jubatus)
The milk oligosaccharides were studied for two species of the Carnivora: the American black bear (Ursus americanus, family Ursidae, Caniformia), and the cheetah, (Acinonyx jubatus, family Felidae, Feliformia). Lactose was the most dominant saccharide in cheetah milk, while this was a minor saccharide and milk oligosaccharides predominated over lactose in American black bear milk. The structures of 8 neutral saccharides from American black bear milk were found to be Gal(Ξ²1-4)Glc (lactose), Fuc(Ξ±1-2)Gal(Ξ²1-4)Glc (2β-fucosyllactose), Gal(Ξ±1-3)Gal(Ξ²1-4)Glc (isoglobotriose), Gal(Ξ±1-3)[Fuc(Ξ±1-2)]Gal(Ξ²1-4)Glc (B-tetrasaccharide), Gal(Ξ±1-3)[Fuc(Ξ±1-2)]Gal(Ξ²1-4)[Fuc(Ξ±1-3)]Glc (B-pentasaccharide), Fuc(Ξ±1-2)Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc(Ξ²1-3)Gal(Ξ²1-4)Glc (difucosyl lacto-N-neotetraose), Gal(Ξ±1-3)Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc(Ξ²1-3)Gal(Ξ²1-4)Glc (monogalactosyl monofucosyl lacto-N-neotetraose) and Gal(Ξ±1-3)Gal(Ξ²1-4)GlcNAc(Ξ²1-3)Gal(Ξ²1-4)Glc. Structures of 5 acidic saccharides were also identified in black bear milk: Neu5Ac(Ξ±2-3)Gal(Ξ²1-4)Glc (3β-sialyllactose), Neu5Ac(Ξ±2-6)Gal(Ξ²1-4)GlcNAc(Ξ²1-3)[Fuc(Ξ±1-2)Gal(Ξ²1-4)GlcNAc(Ξ²1-6)]Gal(Ξ²1-4)Glc (monosialyl monofucosyl lacto-N-neohexaose), Neu5Ac(Ξ±2-6)Gal(Ξ²1-4)GlcNAc(Ξ²1-3)[Gal(Ξ±1-3)Gal(Ξ²1-4)GlcNAc(Ξ²1-6)]Gal(Ξ²1-4)Glc (monosialyl monogalactosyl lacto-N-neohexaose), Neu5Ac(Ξ±2-6)Gal(Ξ²1-4)GlcNAc(Ξ²1-3){Gal(Ξ±1-3)Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc(Ξ²1-6)}Gal(Ξ²1-4)Glc (monosialyl monogalactosyl monofucosyl lacto-N-neohexaose), and Neu5Ac(Ξ±2-6)Gal(Ξ²1-4)GlcNAc(Ξ²1-3){Gal(Ξ±1-3)[Fuc(Ξ±1-2)]Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc(Ξ²1-6)}Gal(Ξ²1-4)Glc (monosialyl monogalactosyl difucosyl lacto-N-neohexaose). A notable feature of some of these milk oligosaccharides is the presence of B-antigen (Gal(Ξ±1-3)[Fuc(Ξ±1-2)]Gal), Ξ±-Gal epitope (Gal(Ξ±1-3)Gal(Ξ²1-4)Glc(NAc)) and Lewis x (Gal(Ξ²1-4)[Fuc(Ξ±1-3)]GlcNAc) structures within oligosaccharides. By comparison to American black bear milk, cheetah milk had a much smaller array of oligosaccharides. Two cheetah milks contained Gal(Ξ±1-3)Gal(Ξ²1-4)Glc (isoglobotriose), while another cheetah milk did not, but contained Gal(Ξ²1-6)Gal(Ξ²1-4)Glc (6β-galactosyllactose) and Gal(Ξ²1-3)Gal(Ξ²1-4)Glc (3β-galactosyllactose). Two cheetah milks contained Gal(Ξ²1-4)GlcNAc(Ξ²1-3)[Gal(Ξ²1-4)GlcNAc(Ξ²1-6)]Gal(Ξ²1-4)Glc (lacto-N-neohexaose), and one cheetah milk contained Gal(Ξ²1-4)Glc-3β-O-sulfate. Neu5Ac(Ξ±2-8)Neu5Ac(Ξ±2-3)Gal(Ξ²1-4)Glc (disialyllactose) was the only sialyl oligosaccharide identified in cheetah milk. The heterogeneity of milk oligosaccharides was found between both species with respect of the presence/absence of B-antigen and Lewis x. The variety of milk oligosaccharides was much greater in the American black bear than in the cheetah. The ratio of milk oligosaccharides-to-lactose was lower in cheetah (1:1-1:2) than American black bear (21:1) which is likely a reflection of the requirement for a dietary supply of N-acetyl neuraminic acid (sialic acid), in altricial ursids compared to more precocial felids, given the role of these oligosaccharides in the synthesis of brain gangliosides and the polysialic chains on neural cell adhesion
Lack of functional alpha-lactalbumin prevents involution in Cape fur seals and identifies the protein as an apoptotic milk factor in mammary gland involution
The mammary gland undergoes a sophisticated programme of developmental changes during pregnancy/lactation. However, little is known about processes involving initiation of apoptosis at involution following weaning. We used fur seals as models to study the molecular process of involution as these animals display a unique mammary gland phenotype. Fur seals have long lactation periods whereby mothers cycle between secreting copious quantities of milk for 2 to 3 days suckling pups on land, with trips to sea alone to forage for up to 23 days during which time mammary glands remain active without initiating apoptosis/involution.<br /
Prognostic Significance of Vitamin D Receptor Polymorphisms in Head and Neck Squamous Cell Carcinoma
BACKGROUND:In patients with advanced non-small-cell lung cancer, vitamin D receptor (VDR) polymorphisms and haplotypes are reported to be associated with survival. We hypothesized that a similar association would be observed in patients with head and neck squamous-cell carcinoma (HNSCC). METHODS:In a post-hoc analysis of our previous prospective cohort study, VDR polymorphisms including Cdx2 G/A (rs11568820), FokI C/T (rs10735810), BsmI A/G (rs1544410), ApaI G/T (rs7976091), and TaqI T/C (rs731236) were genotyped by sequencing in 204 consecutive patients with HNSCC who underwent tumor resection. Progression-free survival was compared between VDR polymorphisms using Kaplan-Meier survival curves with log-rank tests and Cox proportional hazard models adjusting for age, gender, smoking status, primary tumor sites, postoperative stages, existence of residual tumor, and postoperative treatment with chemotherapy or radiotherapy. RESULTS:During a median follow-up of 1,047 days, tumor progression and death occurred in 76 (37.3%) and 27 (13.2%) patients, respectively. The FokI T/T genotype was associated with poor progression-free survival: median survival for T/T was 265 days compared with 1,127 days for C/C or C/T (log-rank test: Pβ=β0.0004; adjusted hazard ratio, 3.03; 95% confidence interval, 1.62 to 5.67; Pβ=β0.001). In contrast, the other polymorphisms (Cdx2, BsmI, ApaI, TaqI) showed no significant association with progression-free survival. The A-T-G (Cdx2-FokI-ApaI) haplotype demonstrated a significant association with a higher progression rate (Pβ=β0.02). CONCLUSION:These results suggest that VDR polymorphisms and haplotypes may be associated with prognosis in patients with HNSCC, although the sample size is not large enough to draw definitive conclusions
Serum vitamin D levels and survival of patients with colorectal cancer: Post-hoc analysis of a prospective cohort study
<p>Abstract</p> <p>Background</p> <p>Recently, serum 25-hydroxyvitamin D (25OHD) levels were shown to be associated with the survival of patients with colorectal cancer. However, 25OHD levels were measured a median of 6 years before diagnosis or were predicted levels. In this study, we directly measured serum 25OHD levels at surgery and examined the association with survival among patients with colorectal cancer.</p> <p>Methods</p> <p>We started a prospective cohort study to find prognostic factors in patients with colorectal cancer from 2003 to 2008 and stored serum samples and clinical data. As part of a post-hoc analysis, serum 25OHD levels were measured by radioimmunoassay. Association between overall survival and serum 25OHD levels were computed using the Cox proportional hazard model adjusted for month of serum sampling as well as age at diagnosis, gender, cancer stage, residual tumor after surgery, time period of surgery, location of tumor, adjuvant chemotherapy and number of lymph nodes with metastasis at surgery. Unadjusted and adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) were determined.</p> <p>Results</p> <p>Serum 25OHD levels were measured in 257 patients. Only 3% had sufficient levels (30 ng/ml and greater). Based on month of blood sampling, an annual oscillation of 25OHD levels was seen, with levels being lower in spring and higher in late summer. Higher 25OHD levels were associated with better overall survival under multi-variate analysis (HR, 0.91: 95% CI, 0.84 to 0.99, <it>P </it>= 0.027).</p> <p>Conclusions</p> <p>These results suggest that higher 25OHD levels at surgery may be associated with a better survival rate of patients with colorectal cancer.</p
Neutralization of Botulinum Neurotoxin by a Human Monoclonal Antibody Specific for the Catalytic Light Chain
Background: Botulinum neurotoxins (BoNT) are a family of category A select bioterror agents and the most potent biological toxins known. Cloned antibody therapeutics hold considerable promise as BoNT therapeutics, but the therapeutic utility of antibodies that bind the BoNT light chain domain (LC), a metalloprotease that functions in the cytosol of cholinergic neurons, has not been thoroughly explored. Methods and Findings: We used an optimized hybridoma method to clone a fully human antibody specific for the LC of serotype A BoNT (BoNT/A). The 4LCA antibody demonstrated potent in vivo neutralization when administered alone and collaborated with an antibody specific for the HC. In Neuro-2a neuroblastoma cells, the 4LCA antibody prevented the cleavage of the BoNT/A proteolytic target, SNAP-25. Unlike an antibody specific for the HC, the 4LCA antibody did not block entry of BoNT/A into cultured cells. Instead, it was taken up into synaptic vesicles along with BoNT/A. The 4LCA antibody also directly inhibited BoNT/A catalytic activity in vitro. Conclusions: An antibody specific for the BoNT/A LC can potently inhibit BoNT/A in vivo and in vitro, using mechanisms not previously associated with BoNT-neutralizing antibodies. Antibodies specific for BoNT LC may be valuable components o
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