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排序方式: 共有3815条查询结果,搜索用时 609 毫秒
31.
32.
When administered to animals cadmium is known to accumulate in the liver and kidney causing indentifiable toxicity. However, its binding with cell sap and nucleus and effects on their constituents are poorly known. Since nuclear changes reflect some of the metabolic disturbances and are of value in diagnosis, an attempt has been made to analyse their morphology and chemistry in the liver and kidney of rat after individual and combined treatment with Cd and Zn. Present observations clearly show that cadmium inhibits DNA synthesis by blocking the formation of the enzyme thymidine triphosphate which is prerequisite for DNA synthesis. Zinc exerted a stimulatory effect on DNA and RNA both by increasing the activity of thymidine kinase. Their combined effects were found to be less injurious to the cell. Though these changes could be a secondary or generalized response of nuclei to altered physiological conditions, specific reasons for these changes have been discussed. 相似文献
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Reverse micelle and chemical hydrolysis techniques have been successfully combined to synthesize composite nanoparticles consisting of a photocatalytic shell of titania and a magnetic core of nickel ferrite. The nature of titania shell, i.e. anatase or brookite, depends on the TiO2 and NiFe2O4 molar ratio. The work presented here describes the photocatalytic and anti-microbial activity of the composite nanoparticles together with the magnetic characteristics of the nickel ferrite core. The TiO2-coated NiFe2O4 nanoparticles retain the magnetic characteristics of uncoated nanocrystalline nickel ferrites (superparamagnetism; absence of hysteresis, remanence and coercivity at 300 K) encouraging their application as removable anti-microbial photocatalyst nanoparticles that can be extracted from the sprayed surface (human body or environment) after exposure. 相似文献
35.
Nagarkatti R Kumar R Sharma SK Ghosh B 《International archives of allergy and immunology》2004,134(3):206-212
BACKGROUND: Asthma is a complex airway disorder, and a number of genetic loci have been found to be associated with asthma. The 5q31-33 region is one of the most important loci linked to asthma and atopic disorders. However, association studies with candidate genes in this region, such as IL4, were inconclusive, as both positive and negative results were obtained in several populations studied. The aim of our case-control study was to determine the association between IL4 and asthma in North Indians. PATIENTS AND METHODS: Polymorphisms in the promoter and a dinucleotide repeat in the 2nd intron in IL4 were genotyped by sequencing and GeneScan analysis, respectively, in ethnically matched, unrelated patients (n = 171) and controls (n = 128), following the guidelines of the American Thoracic Society. RESULTS: The proximal promoter region of the IL4 gene was found to be invariant. Previously reported polymorphisms, -590 C/T and +33 C/T, were found to be absent in our population. The chi2 test using only large expected cell counts (more than 5% of the sample size) showed a significant association between allele size and disease status (chi2 = 38.08, d.f. = 6, p < 0.05). In addition, a significant difference was observed for the allele and genotype frequencies (p < 0.0005 and p = 0.0009, respectively) in the patient and the control groups using the Fisher-Freeman-Halton test. CONCLUSION: Our studies indicate that the promoter of the IL4 gene is invariant in our population. The case-control studies on the CA repeat polymorphism in the 2nd intron of the IL4 gene have shown interesting results and indicate the need for further family-based studies. 相似文献
36.
Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP) 总被引:8,自引:0,他引:8
Rowe PS; Oudet CL; Francis F; Sinding C; Pannetier S; Econs MJ; Strom TM; Meitinger T; Garabedian M; David A; Macher MA; Questiaux E; Popowska E; Pronicka E; Read AP; Mokrzycki A; Glorieux FH; Drezner MK; Hanauer A; Lehrach H; Goulding JN; O'Riordan JL 《Human molecular genetics》1997,6(4):539-549
Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with
homologies to endopeptidases, on the X-chromosome), are responsible for
X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family
of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has
raised important questions regarding PEX function at the molecular level.
The aim of this study was to analyse 99 HYP families for PEX gene
mutations, and to correlate predicted changes in the protein structure with
Zn2+ metallopeptidase gene function. Primers flanking 22 characterised
exons were used to amplify DNA by PCR, and SSCP was then used to screen for
mutations. Deletions, insertions, nonsense mutations, stop codons and
splice mutations occurred in 83% of families screened for in all 22 exons,
and 51% of a separate set of families screened in 17 PEX gene exons.
Missense mutations in four regions of the gene were informative regarding
function, with one mutation in the Zn2+-binding site predicted to alter
substrate enzyme interaction and catalysis. Computer analysis of the
remaining mutations predicted changes in secondary structure,
N-glycosylation, protein phosphorylation and catalytic site molecular
structure. The wide range of mutations that align with regions required for
protease activity in NEP suggests that PEX also functions as a protease,
and may act by processing factor(s) involved in bone mineral metabolism.
相似文献
37.
Rigor and resistance to stretch in vertebrate smooth muscle 总被引:2,自引:0,他引:2
38.
39.
Munaza Fatima Santosh Kumar Mudassar Hussain Naveed Masood Memon Anum Vighio Muhammad Asif Syed Ambreen Chaudhry Zakir Hussain Zeeshan Iqbal Baig Mirza Amir Baig Rana Jawad Asghar Aamer Ikram Yousef Khader 《JMIR Public Health and Surveillance》2021,7(5)
BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures. 相似文献
40.
Rana Roshane-Shahid Nazim Syed M. Ather M. Hammad 《International urology and nephrology》2021,53(1):21-26
International Urology and Nephrology - To evaluate the acute renal colic score (ARC) in predicting the need of emergency intervention (EI) in patients with ureteric colic secondary to a ureteral... 相似文献