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181.
Eyong KO Folefoc GN Kuete V Beng VP Krohn K Hussain H Nkengfack AE Saeftel M Sarite SR Hoerauf A 《Phytochemistry》2006,67(6):605-609
The study of the chemical constituents of the roots of Newbouldia laevis (Bignoniaceae) has resulted in the isolation and characterization of a naphthoquinone-anthraquinone coupled pigment named newbouldiaquinone A (1) together with 14 known compounds: apigenin, chrysoeriol, newbouldiaquinone, lapachol, 2-methylanthraquinone, 2-acetylfuro-1,4-naphthoquinone, 2,3-dimethoxy-1,4-benzoquinone, oleanolic acid, canthic acid, 2-(4-hydroxyphenyl)ethyl triacontanoate, newbouldiamide, 5,7-dihydroxydehydroiso-alpha-lapachone, beta-sitosterol, and beta-sitosterol glucopyranoside. The structure elucidation of the isolated compounds was established based on spectroscopic studies, notably of the 2D NMR spectra. The antimalarial activity of compound (1) against Plasmodium falciparum in vitro shows moderate chemo suppression of parasitic growth. Its antimicrobial activity against a wide range of microorganisms was 13- and 24-fold more active against Candida gabrata and Enterobacter aerogens than the reference antibiotics nystatin and gentamycin. 相似文献
182.
Fu Z Runquist JA Forouhar F Hussain M Hunt JF Miziorko HM Kim JJ 《The Journal of biological chemistry》2006,281(11):7526-7532
3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase is a key enzyme in the ketogenic pathway that supplies metabolic fuel to extrahepatic tissues. Enzyme deficiency may be due to a variety of human mutations and can be fatal. Diminished activity has been explained based on analyses of recombinant human mutant proteins or, more recently, in the context of structural models for the enzyme. We report the experimental determination of a crystal structure at 2.1 A resolution of the recombinant human mitochondrial HMG-CoA lyase containing a bound activator cation and the dicarboxylic acid 3-hydroxyglutarate. The enzyme adopts a (betaalpha)(8) barrel fold, and the N-terminal barrel end is occluded. The structure of a physiologically relevant dimer suggests that substrate access to the active site involves binding across the cavity located at the C-terminal end of the barrel. An alternative hypothesis that involves substrate insertion through a pore proposed to extend through the barrel is not compatible with the observed structure. The activator cation ligands included Asn(275), Asp(42),His(233), and His(235); the latter three residues had been implicated previously as contributing to metal binding or enzyme activity. Arg(41), previously shown to have a major effect on catalytic efficiency, is also located at the active site. In the observed structure, this residue interacts with a carboxyl group of 3-hydroxyglutarate, the hydrolysis product of the competitive inhibitor 3-hydroxyglutaryl-CoA required for crystallization of human enzyme. The structure provides a rationale for the decrease in enzyme activity due to clinical mutations, including H233R, R41Q, D42H, and D204N, that compromise active site function or enzyme stability. 相似文献
183.
Lodhi MA Hussain J Abbasi MA Jassbi AR Choudhary MI Ahmad VU 《Journal of enzyme inhibition and medicinal chemistry》2006,21(5):531-535
Inhibition of Bacillus pasteurii urease enzyme by 3,7,15-tri-O-acetyl-5-O-nicotinoyl-13,14-dihydroxymyrsinol (1), a diterpene ester with a myrsinol-type skeleton, isolated from Euphorbia decipiens Boiss. and Buhse, was un-competitive consistent with the molecular docking results. The Ki value was 117.40 +/- 0.7 microM. 相似文献
184.
Background
Patients with aero-digestive malignancy will often require a feeding gastrostomy during their treatment to maintain their nutritional status. These are usually placed percutaneously using an endoscopic technique.Case presentation
A fifty-six year old male underwent placement of a percutaneous gastrostomy (PEG) prior to commencement of his treatment for an oral squamous cell carcinoma. The treatment for this was locally curative. However, he developed a metastasis at the site of his PEG tube. This was excised en-bloc with the anterior gastric and abdominal walls.Conclusion
Tumour implantation into wounds has been previously reported. In this case the direct trauma of passing the PEG tube through the oropharynx led to implantation of cells in the anterior abdominal wall. In these cases laparoscopic placement may be more beneficial to avoid this problem. 相似文献185.
Techniques of EMG signal analysis: detection, processing, classification and applications 总被引:1,自引:0,他引:1
Electromyography (EMG) signals can be used for clinical/biomedical applications, Evolvable Hardware Chip (EHW) development,
and modern human computer interaction. EMG signals acquired from muscles require advanced methods for detection, decomposition,
processing, and classification. The purpose of this paper is to illustrate the various methodologies and algorithms for EMG
signal analysis to provide efficient and effective ways of understanding the signal and its nature. We further point up some
of the hardware implementations using EMG focusing on applications related to prosthetic hand control, grasp recognition,
and human computer interaction. A comparison study is also given to show performance of various EMG signal analysis methods.
This paper provides researchers a good understanding of EMG signal and its analysis procedures. This knowledge will help them
develop more powerful, flexible, and efficient applications. 相似文献
186.
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188.
The precise characterization of post translational modifications (PTMs) is important for the understanding of protein regulatory
mechanisms and their role in disease. However, experimental studies on PTMs, especially with multifunctional proteins are
difficult to follow and investigate. Bioinformatic tools are therefore helpful in predicting key protein modifications. To
study the role of PTMs in claudin proteins, specifically claudin-1, -3 and -4 in the onset or progression of human cancers,
we performed an in silico study of various PTMs and investigated their interplay. Given that the activity of claudins is known
to be influenced by two types of PTMs, specifically palmitoylation and kinase- dependent phosphorylation, we predicted two
conserved regions in the topological domains of claudin-1, -3 and -4 as potential palmitoylation sites. Furthermore, conserved
phosphorylation residues, which may be targets for kinases and can alter claudin’s ability to maintain the integrity of tight
junctions, were identified. To our knowledge, this is the first report to suggest O-glycosylation of claudin proteins, as well as a potential novel interplay between phosphorylation and O-glycosylation at Yin Yang sites. Thus, our findings may facilitate the production of anti-cancer drugs, and suggest that
novel therapeutic strategies should target post translational events. 相似文献
189.
In tropical and subtropical regions of the world, parasitic diseases are major obstacle in the health and ultimately overall
performance of animals. Cattle express heritable, contrasting phenotypes when exposed to ticks depicting genetic nature of
trait. IFN-γ is one of the most reported genes critical for innate and adaptive immunity against viral and intracellular infections.
To identify its role in resistance for ectoparasite especially tick, genetic characterization of this gene was done in resistant
and susceptible animals of Sahiwal cattle (n = 95) and Friesian (n = 92). Nine Polymorphisms were identified, three of them were found in exonic region. One out of nine variants was being
reported previously (ss82716193) and was confirmed in Pakistani Sahiwal cattle population as well. Single site analysis of
each variant depicted their significance in tick resistant and tick susceptible groups (P < 0.05). The associations using haplotypes were more informative than for single markers. Eighteen different haplotypes resulting
from nine polymorphic sites were used in construction of maximum parsimony tree which categorized resistant and susceptible
animals in two clades. Genetic markers identified in this study can be useful in future breeding selection programs against
tick resistance. 相似文献
190.
Thakur N Hussain S Nasare V Das BC Basir SF Bharadwaj M 《Molecular biology reports》2012,39(1):407-414
The potent tumor suppressors P16 and RB1 are the key regulators of cell cycle machinery in eukaryotes. Polymorphisms in these
genes play an important role in the outcome of various diseases including cancer. In the present study, we evaluated the association
of p16 and RB1 polymorphisms with cervical cancer susceptibility in Indian population. We screened 150 histologically confirmed
cervical cancer cases along with equal number of healthy controls with normal cervical cytology. PCR-RFLP method was employed
for genotyping of SNPs in p16 C540G (rs11515), C580T (rs3088440) in the 3′-UTR of exon 3 and RB1 A153104G (rs4151580) located
in the intron 18 and confirmed by direct sequencing. Both patients and controls were screened for HPV infection. In this case–control
study 84.67% (127/150) of cases were found to be positive for HPV DNA sequence. Women carrying p16 C540G carrier genotypes
540 (CG/GG) may have protective effect for the development of cervical cancer (P = 0.0001, OR = 0.31, 95% CI = 0.17–0.56). And SNP at C580T of p16 gene was found to be negatively associated with the risk
of cervical cancer (P = 0.0004, OR = 0.04, 95% CI = 0.002–0.63). p16 (540C/580T) has emerged as a major risk haplotype (P = 0.033, OR = 1.47, 95% CI = 1.05–2.07) whereas p16 (540G/580T) as a chief protective haplotype (P = 0.014, OR = 0.39, 95% CI = 0.18–0.83) for the development of cervical cancer among Indian women. Contrary to this, SNP
at A153104G of RB1 gene showed statistically significant association (P = 0.035, OR = 1.69, 95% CI = 1.06–2.68) with increased susceptibility for the development of cervical cancer. Our results
suggest that single nucleotide polymorphisms in p16, RB1 genes may affect the susceptibility to cervical cancer collectively. 相似文献