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41.
Esther E. Uchendu Magfrat Muminova Sandhya Gupta Barbara M. Reed 《In vitro cellular & developmental biology. Plant》2010,46(4):386-393
Regrowth of plants after cryopreservation varies, and resulting regrowth ranges from poor to excellent. Oxidative stress is
a potential cause of damage in plant tissues. Antioxidants and anti-stress compounds may improve regrowth by preventing or
repairing the damage. Lipoic acid (LA), glutathione (GSH), glycine betaine (GB), and polyvinylpyrrolidone (PVP) were tested
during cryopreservation of shoot tips using the plant vitrification solution 2 (PVS2) protocol. Two in vitro-grown blackberry cultivars were cold acclimated and then cryopreserved in liquid nitrogen (LN). The antioxidant and anti-stress
compounds were added at four critical steps of the protocol: pretreatment, loading, rinsing, and regrowth. Three out of the
four compounds significantly improved regrowth of cryopreserved shoot tips. Regrowth ranged from 40% to 50% for controls to
>80% for treated shoot tips. LA (4-8 mM) produced high regrowth at pretreatment, loading, and rinsing for ‘Chehalem’ and at
all steps for ‘Hull Thornless’. Recovery improved at all steps with GSH (0.16 mM) and GB (10 mM). PVP had a neutral or negative
impact on regrowth. Overall addition of LA, GSH, and GB improved regrowth by ∼25% over the shoot tips cryopreserved using
the regular PVS2 protocol (control). This study shows that adding non-vitamin antioxidants and anti-stress compounds during
the PVS2-vitrification protocol improves regrowth of shoot cultures following cryopreservation. We recommend inclusion of
antioxidants as part of standard cryopreservation protocols. 相似文献
42.
The present study was directed to the production of N-acetyl-D-glucosamine using endochitinase and chitobiase from fungal cultures in solid culturing. Fifteen fungal strains were evaluated for endochitinase and chitobiase production under solid-state fermentation using agro-industrial residues, of which Penicillium aculeatum NRRL 2129 showed maximum endochitinase activity whereas Trichoderma harzianum TUBF 927 showed maximum chitobiase activity. Eleven substrates, alone and in combination with chitin, were evaluated for the enzyme production. Optimization of physico-chemical parameters such as incubation period and initial moisture content, and nutritional parameters such as chitin source, inorganic and organic nitrogen sources, were carried out. Optimization resulted in more than 3-fold increase in endochitinase production (from 3.5 to 12.53 U/g dry weight of substrate) and about 1.5-fold increase in chitobiase production (from 1.6 to 2.25 U/g dry weight of substrate). Studies on the degradation of colloidal chitin to N-acetyl-D-glucosamine showed improved efficiency when endochitinase and chitobiase were used in combination. 相似文献
43.
44.
Ram Reddy T Srinivasula Reddy L Rajeshwar Reddy G Nuthalapati VS Lingappa Y Sandra S Kapavarapu R Misra P Pal M 《Bioorganic & medicinal chemistry letters》2011,21(21):6433-6439
A multi component based synthesis involving palladium catalyzed C-C bond forming reaction has been developed as a new strategy to access systematically modified functionalized 2-aminochromenes. This MCR involves the use of bromobenzaldehyde as a key component and is highlighted by generating a new compound library. Many of these compounds showed Mycobacterium tuberculosis H37Rv chorismate mutase inhibiting properties in vitro representing the lead example of chorismate mutase inhibition by heteroarene based compounds. 相似文献
45.
Background
In the general population, peripheral metabolic complications (MC) increase the risk for left ventricular dysfunction. Human immunodeficiency virus infection (HIV) and combination anti-retroviral therapy (cART) are associated with MC, left ventricular dysfunction, and a higher incidence of cardiovascular events than the general population. We examined whether myocardial nutrient metabolism and left ventricular dysfunction are related to one another and worse in HIV infected men treated with cART vs. HIV-negative men with or without MC.Methods
Prospective, cross-sectional study of myocardial glucose and fatty acid metabolism and left ventricular function in HIV+ and HIV-negative men with and without MC. Myocardial glucose utilization (GLUT), and fatty acid oxidation and utilization rates were quantified using 11C-glucose and 11C-palmitate and myocardial positron emission tomography (PET) imaging in four groups of men: 23 HIV+ men with MC+ (HIV+/MC+, 42 ± 6 yrs), 15 HIV+ men without MC (HIV+/MC-, 41 ± 6 yrs), 9 HIV-negative men with MC (HIV-/MC+, 33 ± 5 yrs), and 22 HIV-negative men without MC (HIV-/MC-, 25 ± 6 yrs). Left ventricular function parameters were quantified using echocardiography.Results
Myocardial glucose utilization was similar among groups, however when normalized to fasting plasma insulin concentration (GLUT/INS) was lower (p < 0.01) in men with metabolic complications (HIV+: 9.2 ± 6.2 vs. HIV-: 10.4 ± 8.1 nmol/g/min/μU/mL) than men without metabolic complications (HIV+: 45.0 ± 33.3 vs. HIV-: 60.3 ± 53.0 nmol/g/min/μU/mL). Lower GLUT/INS was associated with lower myocardial relaxation velocity during early diastole (r = 0.39, p < 0.001).Conclusion
Men with metabolic complications, irrespective of HIV infection, had lower basal myocardial glucose utilization rates per unit insulin that were related to left ventricular diastolic impairments, indicating that well-controlled HIV infection is not an independent risk factor for blunted myocardial glucose utilization per unit of insulin.Trial Registration
NIH Clinical Trials NCT00656851 相似文献46.
Ohlsson C Wallaschofski H Lunetta KL Stolk L Perry JR Koster A Petersen AK Eriksson J Lehtimäki T Huhtaniemi IT Hammond GL Maggio M Coviello AD;EMAS Study Group Ferrucci L Heier M Hofman A Holliday KL Jansson JO Kähönen M Karasik D Karlsson MK Kiel DP Liu Y Ljunggren O Lorentzon M Lyytikäinen LP Meitinger T Mellström D Melzer D Miljkovic I Nauck M Nilsson M Penninx B Pye SR Vasan RS Reincke M Rivadeneira F Tajar A Teumer A Uitterlinden AG Ulloor J Viikari J Völker U Völzke H Wichmann HE Wu TS 《PLoS genetics》2011,7(10):e1002313
Testosterone concentrations in men are associated with cardiovascular morbidity, osteoporosis, and mortality and are affected by age, smoking, and obesity. Because of serum testosterone''s high heritability, we performed a meta-analysis of genome-wide association data in 8,938 men from seven cohorts and followed up the genome-wide significant findings in one in silico (n = 871) and two de novo replication cohorts (n = 4,620) to identify genetic loci significantly associated with serum testosterone concentration in men. All these loci were also associated with low serum testosterone concentration defined as <300 ng/dl. Two single-nucleotide polymorphisms at the sex hormone-binding globulin (SHBG) locus (17p13-p12) were identified as independently associated with serum testosterone concentration (rs12150660, p = 1.2×10−41 and rs6258, p = 2.3×10−22). Subjects with ≥3 risk alleles of these variants had 6.5-fold higher risk of having low serum testosterone than subjects with no risk allele. The rs5934505 polymorphism near FAM9B on the X chromosome was also associated with testosterone concentrations (p = 5.6×10−16). The rs6258 polymorphism in exon 4 of SHBG affected SHBG''s affinity for binding testosterone and the measured free testosterone fraction (p<0.01). Genetic variants in the SHBG locus and on the X chromosome are associated with a substantial variation in testosterone concentrations and increased risk of low testosterone. rs6258 is the first reported SHBG polymorphism, which affects testosterone binding to SHBG and the free testosterone fraction and could therefore influence the calculation of free testosterone using law-of-mass-action equation. 相似文献
47.
Hansson J Vasan RS Ärnlöv J Ingelsson E Lind L Larsson A Michaëlsson K Sundström J 《PloS one》2011,6(1):e16185
Objective
Turnover of the extracellular matrix in all solid organs is governed mainly by a balance between the degrading matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). An altered extracellular matrix metabolism has been implicated in a variety of diseases. We investigated relations of serum levels of MMP-9 and TIMP-1 to mortality risk from an etiological perspective.Design
The prospective Uppsala Longitudinal Study of Adult Men (ULSAM) cohort, followed from 1991–1995 for up to 18.1 years. A random population-based sample of 1,082 71-year-old men, no loss to follow-up. Endpoints were all-cause (n = 628), cardiovascular (n = 230), non-cardiovascular (n = 398) and cancer mortality (n = 178), and fatal or non-fatal myocardial infarction (n = 138) or stroke (n = 163).Results
Serum MMP-9 and TIMP-1 levels were associated with risk of all-cause mortality (Cox proportional hazard ratio [HR] per standard deviation 1.10, 95% confidence interval [CI] 1.03–1.19; and 1.11, 1.02–1.20; respectively). TIMP-1 levels were mainly related to risks of cardiovascular mortality and stroke (HR per standard deviation 1.22, 95% CI 1.09–1.37; and 1.18, 1.04–1.35; respectively). All relations except those of TIMP-1 to stroke risk were attenuated by adjustment for cardiovascular disease risk factors. Relations in a subsample without cardiovascular disease or cancer were similar to those in the total sample.Conclusion
In this community-based cohort of elderly men, serum MMP-9 and TIMP-1 levels were related to mortality risk. An altered extracellular matrix metabolism may be involved in several detrimental pathways, and circulating MMP-9 or TIMP-1 levels may be relevant markers thereof. 相似文献48.
Sandhya S Chakrabarti S Abhinandan KR Sowdhamini R Srinivasan N 《Journal of biomolecular structure & dynamics》2005,23(3):283-298
Profile-based sequence search procedures are commonly employed to detect remote relationships between proteins. We provide an assessment of a Cascade PSI-BLAST protocol that rigorously employs intermediate sequences in detecting remote relationships between proteins. In this approach we detect using PSI-BLAST, which involves multiple rounds of iteration, an initial set of homologues for a protein in a 'first generation' search by querying a database. We propagate a 'second generation' search in the database, involving multiple runs of PSI-BLAST using each of the homologues identified in the previous generation as queries to recognize homologues not detected earlier. This non-directed search process can be viewed as an iteration of iterations that is continued to detect further homologues until no new hits are detectable. We present an assessment of the coverage of this 'cascaded' intermediate sequence search on diverse folds and find that searches for up to three generations detect most known homologues of a query. Our assessments show that this approach appears to perform better than the traditional use of PSI-BLAST by detecting 15% more relationships within a family and 35% more relationships within a superfamily. We show that such searches can be performed on generalized sequence databases and non-trivial relationships between proteins can be detected effectively. Such a propagation of searches maximizes the chances of detecting distant homologies by effectively scanning protein "fold space". 相似文献
49.
Mutational study of the bacterial hemoglobin distal heme pocket 总被引:1,自引:0,他引:1
Verma S Patel S Kaur R Chung YT Duk BT Dikshit KL Stark BC Webster DA 《Biochemical and biophysical research communications》2005,326(2):290-297
Ligand binding experiments on three mutants in the distal heme pocket of Vitreoscilla hemoglobin (GlnE7His, ProE8Ala, and GlnE7His,ProE8Ala) were used to probe the role of GlnE7 and ProE8 in the pocket's unusual structure. The oxygen dissociation constants for the wild type, E8Ala mutant, and E7His mutant proteins were 4.5, 4.7, and 1.7microM, respectively; the K(d) for the double mutant was not determinable by our technique. Visible-Soret spectra of the carbonyl and cyanyl forms and FT-IR of the carbonyl form of the E8 mutant were similar to those of the wild type; the opposite was true for the GlnE7His and GlnE7His,ProE8Ala mutants, which also differed from wild type in the visible-Soret spectra of their oxidized forms. Models of the effects of the mutations on distal pocket structure were consistent with the experimental findings, particularly the larger effects of the GlnE7His change. 相似文献
50.
Chattopadhyay D Dungdung SR Das K Saha S Mandal AB Majumder GC 《Indian journal of experimental biology》2005,43(11):1104-1109
The role of methanolic extract and n-butanol fraction of A. macrophylla leaves was investigated on the forward motility of goat spermatozoa. The methanol extract (600 micro/g/ml) and one n-butanol fraction (Fraction A; 100 microg/ml) showed marked inhibition of sperm forward motility, tested by microscopic and spectrophotometric methods. Approximately, 50-60% of the spermatozoa lost their motility when treated with 600 microg/ml of methanol extract or 100 microg/ml of Fraction A. The Fraction A at 400 microg/ml concentration showed complete inhibition of sperm forward motility at 0 min. The inhibitory activity increased with the increasing concentrations of the fraction. The motility inhibitory activity of the Fraction A was stable to heat treatment at 100 degrees C for 2 min. The compound showed high inhibitory effect in the pH range 6.7-7.6. Fraction A also showed high efficacy for inhibiting human sperm motility, assessed by the microscopic method. The phytochemical analysis of methanolic extract of A. macrophylla leaves revealed the presence of sterols, triterpene, flavonoid, alkaloid, tannin and reducing sugar, while the Fraction A contains beta-sitosterol, a common phytosterol. The results demonstrate that Fraction A (beta-sitosterol) is a potent inhibitor of sperm motility and thus it has the potential to serve as a vaginal contraceptive. 相似文献