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671.
672.
Amenzoui K Ferhan-Tachinante F Yahyaoui A Kifani S Mesfioui AH 《Comptes rendus biologies》2006,329(11):892-901
This work focuses on aspects of reproductive biology of Sardina pilchardus from the Atlantic coast of Morocco. The mean values of batch fecundity estimated for the species is 23150(+/-1301) oocytes for a mean size of 19.5(+/-0.49) cm, the mean relative fecundity being 346(+/-7.34) oocytes per gram of female without ovary. Batch fecundity increases with total length and body weight without ovary. Sizes at first sexual maturity (L50) are reached for males and females at 15.8(+/-0.29) cm and 15.8(+/-0.35) cm, respectively. The spawning period for the population extends between October and July and the spawning peak occurs from October to February. However, the small sardines (14.5-17 cm) in their first reproduction spawn between November and June, whereas larger fish (17.5-25 cm) spawn between October and July. The factor of condition (K) increased in summer during the sexual resting phase. It is weak in winter during the period of reproduction. Regarding, the sex ratio, there was no significant difference in the number of males and females. 相似文献
673.
Mahmoud M El-Mas Jian Zhang Abdel A Abdel-Rahman 《Journal of applied physiology》2006,100(3):1011-1018
Previous reports from our laboratory have shown that ethanol elicits hypotension in female but not in male rats and that this effect of ethanol is estrogen dependent (El-Mass MM and Abdel-Rahman AA. Alcohol Clin Exp Res 23: 624-632, 1999; El-Mass MM and Abdel-Rahman AA. Clin Exp Hypertens 21: 1429-1445, 1999). In the present study, we tested the hypothesis that ethanol lowers blood pressure in female rats via upregulation of the inducible nitric oxide synthase (iNOS) in vascular tissues. The effects of pretreatment with NG-nitro-L-arginine (NOARG; nonselective nitric oxide synthase inhibitor) or aminoguanidine (selective iNOS inhibitor) on hemodynamic responses elicited by intragastric (ig) ethanol were determined in conscious female rats. Changes in vascular (aortic) iNOS protein expression evoked by ethanol in the presence and absence of aminoguanidine were also measured by immunohistochemistry. Compared with control (water treated) female rats, ethanol (1 g/kg ig) elicited hypotension that was associated with a significant increase in the aortic iNOS activity. The hypotensive effect of ethanol was virtually abolished in rats infused with the nitric oxide synthase inhibitor NOARG, suggesting a role for nitric oxide in ethanol hypotension. The inability of ethanol to lower blood pressure in NOARG-treated rats cannot be attributed to the presence of elevated blood pressure in these rats because ethanol produced hypotension when blood pressure was raised to comparable levels with phenylephrine infusion. Selective inhibition of iNOS by aminoguanidine (45 mg/kg ip), which had no effect on baseline blood pressure, abolished both the hypotensive action of subsequently administered ethanol and the associated increases in aortic iNOS content. These findings implicate vascular iNOS, at least partly, in the acute hypotensive action of ethanol in female rats. 相似文献
674.
El Ashry ES Awad LF Abdel Hamid HM Atta AI 《Nucleosides, nucleotides & nucleic acids》2006,25(3):325-335
The condensation of D-glucono- and D-galactono-1,5-lactone and thiocarbohydrazide to give 3-(D-alditol-1-yl)-4-amino-5-mercapto-1,2,4-triazoles 4 and 5 is accelerated by the use of microwave-assisted organic reaction (MAOS). The deamination and dethiolation of compound 4 to give 6 was also accelerated by the use of MAOS. Condensation of 4 and 5 with p-nitrobenzaldehyde afforded Schiff bases 8 and 9, respectively, within 4 min under microwave irradiation (MWI), whereas with ethyl chloroacetate the thioalkylated products 14 and 15 were obtained in 8 min. The structures of the synthesized compounds were confirmed by 1H NMR, 2D NMR, and mass spectra. 相似文献
675.
Matthew D. Burgess Kim D. Moore Gay M. Carter Abdel A. Alli Christopher S. Granda Hirohito Ichii Camillo Ricordi William R. GowerJr 《Histochemistry and cell biology》2009,132(1):95-103
Atrial natriuretic peptide (ANP), brain type natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) comprise a family
of natriuretic peptides that mediate their biological effects through three natriuretic peptide receptor subtypes, NPR-A (ANP,
BNP), NPR-B (CNP) and NPR-C (ANP, BNP, CNP). Several reports have provided evidence for the expression of ANP and specific
binding sites for ANP in the pancreas. The purpose of this study was to identify the ANP receptor subtype and to localize
its expression to a specific cell type in the human pancreas. NPR-C immunoreactivity, but neither ANP nor NPR-A, was detected
in human islets by immunofluorescent staining. No immunostaining was observed in the exocrine pancreas or ductal structures.
Double-staining revealed that NPR-C was expressed mainly in the glucagon-containing alpha cells. NPR-C mRNA and protein were
detected in isolated human islets by RT-PCR and Western blot analysis, respectively. NPR-C expression was also detected by
immunofluorescent staining in glucagonoma but not in insulinoma. ANP, as well as BNP and CNP, stimulated glucagon secretion
from perifused human islets (1,111 ± 55% vs. basal [7.3 fmol/min]; P < 0.001). This response was mimicked by cANP(4–23), a selective agonist of NPR-C. In conclusion, the NPR-C receptor is expressed
in normal and neoplastic human alpha cells. These findings suggest a role for natriuretic peptides in the regulation of glucagon
secretion from human alpha cells. 相似文献
676.
Ali Hebeish Mohamed Hashem Nihal Shaker Mohamed Ramadan Bahiya El-Sadek Marwa Abdel Hady 《Carbohydrate polymers》2009,78(4):953-960
Four different types of cotton-based fabrics, namely, loom-state cotton, cotton/polyester (50/50), cotton/polyester (35/65) and grey mercerized fabrics were bioscoured and bleached. The four substrates are given enzymatic treatment using cellulase enzyme to affect bio-polishing followed by crosslinking using N,N-dimethylol 4,5-dihydroxyethylene urea (DMDHEU) to affect easy care finishing. In another series of experiments the said bioscoured–bleached substrates were similarly crosslinked followed by bio-polishing. Technical properties of the treated fabric that were monitored include: nitrogen content, loss in fabric weight, tensile strength, elongation at break, tear strength, whiteness index, surface roughness and wrinkle recovery angle. Scanning electron micrograph was also examined. Conclusions arrived at from these studies indicated that: post-crosslinking and pre-crosslinking revealed marginal differences in N%, wrinkle recovery angle and whiteness index, a point which validates the argument that cellulase enzyme could not break down the DMDHEU crosslinks within the molecular structure of cotton-containing fabrics. Meanwhile the surface roughness obtained with pre-crosslinking is a bit higher than those of post-crosslinking. Moreover, post-crosslinking caused higher losses in strength properties than pre-crosslinking. Scanning electron micrograph shows that cotton sample pre-crosslinked is almost smooth than those post-crosslinked. 相似文献
677.
Temperature and pH-responsive hydrogels based on chitosan grafted with poly acrylic acid (PAAc), poly hydroxy propyl methacrylate (PHPMA), poly (vinyl alcohol) (PVA) and gelatin were prepared for controlled drug delivery. These stimuli-responsive hydrogels were synthesized by gamma irradiation technique. The degree of gelation was over 90% and increased as chitosan, AAc and PVA content increased, while the degree of gelation decrease with the increase of gelatin content. The equilibrium swelling studies of hydrogels prepared in various conditions were carried out in an aqueous solution, and the pH sensitivity in the range of 2–9 was investigated. An increase of swelling degree with an increase in the pH was noticed and showed the highest value at pH 9. Also antibiotic drug Oxttetracycline was loaded into the hydrogels and the release studies were carried out at different pH and temperature. The in vitro release profiles of the drug showed that, the release of the drug increased as the time, temperature and pH increased and reached to maximum after 48 h at pH 9. The prepared hydrogels were characterized by using SEM, FTIR, and DSC. 相似文献
678.
The incidence of yeast-induced infections has increased in the last decade, mainly because of the increasing number of immunodeficient patients. Since biofilm production is believed to be responsible for fungal virulence, we propose screening yeasts of various genera in order to determine their ability to form biofilms. This is an important issue because yeast cells that form biofilms are particularly resistant to anti-fungal agents used in human patients. For screening, we used Eladium©, a new polysaccharide produced by a Rhizobium sp., as an alternative gelling agent to agar. We also established the conditions necessary to detect biofilm formation. The adapted medium provides the missing link between liquid and solid media. Its advantages include enhancement of growth of microorganisms and facilitation of quick and easy monitoring of biofilm formation. 相似文献
679.
El‐S. H. Abdel‐Aziz T. El‐Sayed Ali S. B. S. Abdu H. F. Fouad 《Zeitschrift fur angewandte Ichthyologie》2010,26(4):522-527
This work analyses the distribution, histology and ultrastructure of chromaffin cells (CCs) and interrenal tissue (It) in the head kidney of Epinephilus tauvina. Histological examination revealed that chromaffin cells are found in small groups under the endothelium of the posterior cardinal vein (PCV) and are mostly closely associated with the interrenal tissue. Ultrastructure examination confirmed the existence of two main chromaffin cell types, distinguished by different types of secretory granules. The first type was characterized by the presence of vesicles with round, strongly electron dense core granules, which were eccentrically located. Such cells were interpreted as being noradrenaline cells. Meanwhile, cells with vesicles that were completely electron lucent or that contained small less dense eccentric granules were identified as adrenaline cells. Nerve endings were invaginated into the chromaffin cells through synaptic junctions. Interrenal tissue consisted of nests, cords, or strands of cells in contact with the posterior cardinal vein (PCV) and interposed with haematopoietic tissue. Ultrastructure analysis revealed only one interrenal cell type, which contained abundant smooth endoplasmic reticulum (sER) and numerous mitochondria with tubulo‐vesicular cristae, characteristics of steroid‐producing cells. The interrenal tissue cells have different cytological aspects that can be linked to a steroidogenic cell cycle allowing a periodical renewal of organelles. 相似文献
680.
Mohd Saeed Munazzah Tasleem Ambreen Shoib Mohd Adnan Kausar Abdel Moneim E. Sulieman Nadiyah M. Alabdallah Zeina El Asmar Abdelmuhsin Abdelgadir Asma Al-Shammary Md Jahoor Alam Riadh Badroui Maryam Zahin 《Current issues in molecular biology》2022,44(7):2825
Diabetic peripheral neuropathy (DPN) is a common diabetes complication (DM). Aldose reductase -2 (ALR-2) is an oxidoreductase enzyme that is most extensively studied therapeutic target for diabetes-related complications that can be inhibited by epalrestat, which has severe adverse effects; hence the discovery of potent natural inhibitors is desired. In response, a pharmacophore model based on the properties of eplarestat was generated. The specified pharmacophore model searched the NuBBEDB database of natural compounds for prospective lead candidates. To assess the drug-likeness and ADMET profile of the compounds, a series of in silico filtering procedures were applied. The compounds were then put through molecular docking and interaction analysis. In comparison to the reference drug, four compounds showed increased binding affinity and demonstrated critical residue interactions with greater stability and specificity. As a result, we have identified four potent inhibitors: ZINC000002895847, ZINC000002566593, ZINC000012447255, and ZINC000065074786, that could be used as pharmacological niches to develop novel ALR-2 inhibitors. 相似文献