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排序方式: 共有213条查询结果,搜索用时 62 毫秒
31.
Utility of ninhydrin reagent for spectrofluorimetric determination of heptaminol in human plasma
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For the determination of heptaminol (HEP) in its authentic and dosage form as well as in human plasma, a new simple, sensitive and cheap fluorimetric method of analysis was developed and validated. The presented method is based on the reaction between aliphatic primary amino moiety present in HEP with ninhydrin and phenylacetaldehyde using Torell and Stenhagen buffer at pH 8.2 that yields a highly fluorescent derivative which after excitation at 390 nm showed a fluorescence emission at 464 nm. The effects of various experimental factors on both the development and stability of the fluorescent product was evaluated and optimized. In the concentration range (0.5–6.0 μg/ml), the constructed calibration curve was linear with a good correlation coefficient (0.9997) and the calculated limit of detection (LOD) and limit of quantitation (LOQ) were 0.14 and 0.43 respectively. The presented method was successfully applied for determination of Corasore® tablets and validated according to ICH guidelines. 相似文献
32.
The essential oil content of several members of the Myricaceae were examined for chemotaxonomic purposes. The analysis of the essential oils corroborates the suggestion that the Myricaceae should be divided into three genera. The study also suggests that Myrica pusilla and M. macfarlanei are not valid species. The analyses were carried out on the oil obtained from steam distillation of the foliage. Specific oil constituents were identified by GLC and IR. 相似文献
33.
Ultrastructure of spermatogenesis and mature spermatozoa in the flatworm Prosthiostomum siphunculus (Polycladida,Cotylea)
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Mehrez Gammoudi Willi Salvenmoser Abdel Halim Harrath Saïda Tekaya Bernhard Egger 《Cell biology international》2016,40(3):277-288
This is the first study investigating spermatogenesis and spermatozoan ultrastructure in the polyclad flatworm Prosthiostomum siphunculus. The testes are numerous and scattered as follicles ventrally between the digestive ramifications. Each follicle contains the different stages of sperm differentiation. Spermatocytes and spermatids derive from a spermatogonium and the spermatids remain connected by intercellular bridges. Chromatoid bodies are present in the cytoplasm of spermatogonia up to spermatids. During early spermiogenesis, a differentiation zone appears in the distal part of spermatids. A ring of microtubules extends along the entire sperm shaft just beneath the cell membrane. An intercentriolar body is present and gives rise to two axonemes, each with a 9 + “1” micro‐tubular pattern. Development of the spermatid leads to cell elongation and formation of a filiform, mature spermatozoon with two free flagella and with cortical microtubules along the sperm shaft. The flagella exit the sperm shaft at different levels, a finding common for acotyleans, but so far unique for cotylean polyclads. The Golgi complex produces numerous electron‐dense bodies of two types and of different sizes. These bodies are located around a perinuclear row of mitochondria. The elongated nucleus extends almost along the entire sperm body. The nucleus is wide in the proximal part and becomes narrow going towards the distal end. Thread‐like chromatin mixed with electron‐dense intranuclear spindle‐shaped bodies are present throughout nucleus. The general sperm ultrastructure, the presence of intranuclear bodies and a second type of cytoplasmic electron‐dense bodies may provide characters useful for phylogenetic analysis. 相似文献
34.
Romano Ngui Noor Amira Abdul Halim Yamuna Rajoo Yvonne AL Lim Stephen Ambu Komalaveni Rajoo Tey Siew Chang Lu Chan Woon Rohela Mahmud 《The Korean journal of parasitology》2016,54(5):673-678
Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the ‘true’ prevalence of S. stercoralis. 相似文献
35.
Vladimir Bresler Vera Bissinger Avigdor Abelson Halim Dizer Armin Sturm Renate Kratke Lev Fishelson Peter-Diedrich Hansen 《Helgoland Marine Research》1999,53(3-4):219-243
The intensive development of industry and urban structures along the seashores of the world, as well as the immense increase
in marine transportation and other activities, has resulted in the deposition of thousands of new chemicals and organic compounds,
endangering the existence of organisms and ecosystems. The conventional single biomarker methods used in ecological assessment
studies cannot provide an adequate base for environmental health assessment, management and sustainability planning. The present
study uses a set of novel biochemical, physiological, cytogenetic and morphological methods to characterize the state of health
of selected molluscs and fish along the shores of the German North Sea, as well as the Israeli Mediterranean and Red Sea.
The methods include measurement of activity of multixenobiotic resistance-mediated transporter (MXRtr) and the system of active
transport of organic anions (SATOA) as indicators of antixenobiotic defence; glutathione S-transferase (GST) activity as an
indicator of biotransformation of xenobiotics; DNA unwinding as a marker of genotoxicity; micronucleus test for clastogenicity;
levels of phagocytosis for immunotoxicity; cholinesterase (ChE) activity and level of catecholamines as indicators of neurotoxicity;
permeability of external epithelia to anionic hydrophilic probe, intralysosomal accumulation of cationic amphiphilic probe
and activity of non-specific esterases as indicators of cell/tissue viability. Complete histopathological examination was
used for diagnostics of environmental pathology. The obtained data show that the activity of the defensive pumps, MXRtr and
SATOA in the studied organisms was significantly higher in the surface epithelia of molluscs from a polluted site than that
of the same species from control, unpolluted stations, providing clear evidence of response to stress. Enhanced frequency
of DNA lesions (alkaline and acidic DNA unwinding) and micronucleus-containing cells was significantly higher in samples from
polluted sites in comparison to those from the clean sites that exhibited genotoxic and clastogenic activity of the pollutants.
In all the studied molluscs a negative correlation was found between the MXRtr levels of activity and the frequency of micronucleus-containing
hemocytes. The expression of this was in accordance with the level of pollution. The complete histopathological examination
demonstrates significantly higher frequencies of pathological alterations in organs of animals from polluted sites. A strong
negative correlation was found between the frequency of these alterations and MXRtr activity in the same specimens. In addition
to these parameters, a decrease in the viability was noted in molluscs from the polluted sites, but ChE activities remained
similar at most sites. The methods applied in our study unmasked numerous early cryptic responses and negative alterations
of health in populations of marine biota sampled from the polluted sites. This demonstrates that genotoxic, clastogenic and
pathogenic xenobiotics are present and act in the studied sites and this knowledge can provide a reliable base for consideration
for sustainable development.
Received: 2 March 1999 / Received in revised form: 2 August 1999 / Accepted: 3 August 1999 相似文献
36.
Alvarez-Fernández M Halim VA Aprelia M Laoukili J Mohammed S Medema RH 《The Journal of biological chemistry》2011,286(38):33029-33036
37.
Yous S Durieux-Poissonnier S Lipka-Belloli E Guelzim H Bochu C Audinot V Boutin JA Delagrange P Bennejean C Renard P Lesieur D 《Bioorganic & medicinal chemistry》2003,11(5):753-759
Tetrahydronaphthalenic analogues of melatonin have been synthesized and evaluated as melatonin receptor ligands. Introduction of a phenyl substituent in the 3-position of the tetraline ring allows to obtain MT(2) selective ligands. Activity and MT(2) selectivity can be modulated with suitable modifications of the N-acyl substituent. The (+)-(RR)-cis enantiomer of the N-[2-(7-methoxy-3-phenyl-1,2,3,4-tetrahydro-naphthalen-1-yl)ethyl]cyclobutyl carboxamide (14) is one of the most MT(2) selective ligands described until now and behaves as an antagonist. 相似文献
38.
39.
Zhang Yang Adnan Halim Yoshiki Narimatsu Hiren Jitendra Joshi Catharina Steentoft Katrine Ter-Borch Gram Schjoldager Morten Alder Schulz Natalie R. Sealover Kevin J. Kayser Eric Paul Bennett Steven B. Levery Sergey Y. Vakhrushev Henrik Clausen 《Molecular & cellular proteomics : MCP》2014,13(12):3224-3235
40.
Mukhtar Ahmed Daoud Ali Abdel Halim Harrath Tajamul Hussain Nasser Al-Daghri Majed S. Alokail Ravindranath H. Aladakatti Mukhtar Ahmed G. Ghodesawar 《Comptes rendus biologies》2014,337(4):250-257
Boswellia papyrifera and Boswellia carterii diffuses smoke polluting air that adversely affects indoor environment that certainly harm human health. Therefore, this study aims at ascertaining the effect of these plants on gonadal hormones and molecular changes in rat spermatozoa. The animals were exposed to 4 g/kg body weight of B. papyrifera and B. carterii daily for 120 days along with suitable controls. Significant decreases in FSH, LH and testosterone levels were evidenced, along with a reduction of protein, sialic acid, and carnitine levels. In sperm physiology, sperm count, motility, speed decrease, whereas sperm anomalies increase. TEM observation indicates morphological changes in plasma and acrosomal membranes, cytoplasmic droplet in the tail region, vacuolated, and disorganization of the mitochondrial sheath. These findings demonstrate that B. papyrifera and B. carterii smoke affects the process of sperm formation and maturation, which indicates the detrimental effects of these plants on the reproductive system. 相似文献