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31.
The results of a detailed study on the adhesive apparatus of Indian hill stream cyprinid and sisorid fishes are presented. The structure of the mental suctorial disc in the genus Garra is described. Histological study of the mental region of Crossocheilus and Psilorhynchus has also been made and compared with the mental disc of Garra . The muscles of the disc which control its movements in bringing a partial vacuum during adhesion have been investigated. The complexity of the geniohyoideus muscles in Garra is interesting. Variations in the degree of development and histological modifications of the mental disc are exhibited by the fishes of the genus Garra .
A thoracic adhesive apparatus in the form of longitudinal or transverse ridges and grooves is present in the sisorids, Laguvia, Glyptothorax and Pseudecheneis except Gagata . A close study has revealed that the adhesive apparatus of the catfishes works mainly on the principle of friction. The variations in shape, size and location of the adhesive apparatus in various species are correlated to their respective habitats.
Structural variation in the adhesive apparatus of Pseudecheneis is maximum in comparison to that in Laguvia and Glyptothorax . It is discovered that the modifications are associated with the presence of multi-spinous layers, formation of caps by the basal or holdfast cells and with the transformation of loose areolar tissue into thick collagenous dermis. The presence of a pad of adipose tissue in the region of the adhesive apparatus has been reported and its physiological significance as a source of stored food suggested.
The anterior part of the protractor ischii muscle is modified to control the action of the adhesive apparatus. In Pseudecheneis , besides the m. protractor ischii, the ventral part of m. mesioventral is also associated with the adhesive apparatus. 相似文献
A thoracic adhesive apparatus in the form of longitudinal or transverse ridges and grooves is present in the sisorids, Laguvia, Glyptothorax and Pseudecheneis except Gagata . A close study has revealed that the adhesive apparatus of the catfishes works mainly on the principle of friction. The variations in shape, size and location of the adhesive apparatus in various species are correlated to their respective habitats.
Structural variation in the adhesive apparatus of Pseudecheneis is maximum in comparison to that in Laguvia and Glyptothorax . It is discovered that the modifications are associated with the presence of multi-spinous layers, formation of caps by the basal or holdfast cells and with the transformation of loose areolar tissue into thick collagenous dermis. The presence of a pad of adipose tissue in the region of the adhesive apparatus has been reported and its physiological significance as a source of stored food suggested.
The anterior part of the protractor ischii muscle is modified to control the action of the adhesive apparatus. In Pseudecheneis , besides the m. protractor ischii, the ventral part of m. mesioventral is also associated with the adhesive apparatus. 相似文献
32.
In a study of the kinetics of 5-hydroxytryptamine (5-HT) in platelets in 26 hypertensive subjects with a mean systolic and diastolic blood pressure of 153.9 +/- 26.9 and 106.9 +/- 9.1 mm Hg respectively, it has been observed that in hypertensive platelets there was a marked decrease in 5-HT uptake and content, an increase in 5-HT efflux and an accompanying increase in Plasma 5-HT and 5-HIAA levels. Regression analysis of the data indicated a significant correlation between rise in diastolic blood pressure and these changes in 5-HT kinetics. 相似文献
33.
A cytomorphologic diagnosis of tuberculous lymphadenitis by examination of needle aspirates was made in 560 of 1,471 cases of lymphadenopathy studied over two years. Cytologic features were categorized into four groups: epithelioid clusters with or without Langhans's giant cells without necrosis (32.14%), epithelioid clusters with or without Langhans's giant cells with necrosis (50.35%), occasional epithelioid cells without characteristic necrosis/giant cells (2.85%) and necrosis without epithelioid clusters or Langhans's giant cells (14.64%). While a diagnosis of tuberculous lymphadenitis was offered with confidence in the first two groups, constituting about 82.49% cases, aspirates from the third- and fourth-group patients were subjected to Ziehl-Neelsen staining for acid-fast bacilli, which was positive in 12.5% and 75.6% of cases, respectively. 相似文献
34.
A wheat basic protein (WBP) was purified to homogeneity from wheat germ by a protocol involving extraction, centrifugation, batchwise elution from carboxymethylcellulose (CM-52), acidification with trifluoroacetic acid, neutralization and HPLC on a SP5PW cation exchange column. WBP is a 10 kDa protein and is phosphorylated on serine residues by wheat germ Ca(2+)-dependent protein kinase (CDPK). [32P]phosphoWBP exactly comigrates with WBP on SDS-PAGE. WBP does not inhibit either wheat germ CDPK or calmodulin-dependent myosin light chain kinase. Apart from histone H1, WBP is the best endogenous substrate yet found for wheat embryo CDPK. A 12 kDa pine basic protein (PBP) was purified to homogeneity from seeds of stone pine (Pinus pinea L.) by a simple procedure involving batchwise elution from carboxymethylcellulose and cation exchange HPLC. PBP is also a good substrate for CDPK and is phosphorylated on Ser residues. N-terminal sequencing of WBP and PBP revealed that these proteins are homologous to a family of small basic plant proteins having a phospholipid transfer function. 相似文献
35.
We studied the effect on female viability oftrans-heterozygous combinations of X-chromosome deficiencies andSxl f1, a null allele ofSex-lethal. Twentyfive deficiencies, which together covered 80% of the X chromosome, were tested. Seven of thesetrans-hcterozygous combinations caused significant levels of female lethality. Two of the seven interacting deficiencies include the previously known sex determination genessans fills andsisterless-a. Four of the remaining uncover X-chromosomal regions that were not hitherto known to contain sex determination genes. These newly identified regions are defined by deficienciesDf(1)RA2 (7D10; 8A4-5),DJ(1)KA14 (7F1-2; 8C6),Df(1)C52 (8E; 9C-D) andDf(1)NI9 (17A1; 18A2). These four deficiencies were characterized further to determine whether it was the maternal or zygotic dosage that was primarily responsible for the observed lethality of female embryos,daughterless andextra macrochaetae, two known regulators ofSxl, influence the interaction of these deficiencies withSxl. 相似文献
36.
Amaresh Chandra M. Thungapathra Kallash C. Upadhyaya 《Journal of plant biochemistry and biotechnology.》1994,3(1):31-35
The calcium binding protein, calmodulin Is involved in regulating various cellular and biochemical processes. A gene tor calmodulin (CaM) has been Isolated from a genomic library of Arabidopsis thaliana constructed in ; EMBL-4 using a heterologous cDNA probe from electric eel. One of the positive clones was characterized and the region containing the calmodulin gene sequences was Identified, excised using appropriate restriction enzymes and subcloned Into a plasmid vector. The genomic clone contains a complete copy of the calmodulin gene. A comparison of the nucleotide sequence of the part of the clone with those of the other plant and animal systems confirms that the clone In fact contains the calmodulin gene sequences. Southern hybridization ulling the calmodulin gene sequences as a probe reveals the presence of more than one copy of the calmodulin gene. The results of this investigation taken together with those Iff the other. indicate that the calmodulin gene belongs to a small mutigene family consisting of atieast four member. In the Arabidopsis genome. 相似文献
37.
Chandra Prakash Prasad Satyendra Chandra Tripathi Manish Kumar Purusottam Mohapatra 《Biotechnology and bioengineering》2023,120(8):2049-2055
Cancer cell lines play a crucial role as invaluable models in cancer research, facilitating the examination of cancer progression as well as the advancement of diagnostics and treatments. While they may not perfectly replicate the original tumor, they generally exhibit similar characteristics. Low-passage cancer cell lines are generally preferred due to their closer resemblance to the original tumor, as long-term culturing can alter the genetic and molecular profiles of a cell line thereby highlighting the importance of monitoring the passage number (PN). Variations in proliferation, migration, gene expression, and drug sensitivity can be linked to PN differences. PN can also influence DNA methylation levels, metabolic profiles, and the expression of genes/or proteins in cancer cell lines. When conducting research on cancer cell lines, it is crucial for researchers to carefully select the appropriate PN to maintain consistency and reliability of results. Moreover, to ensure dependability and replicability, scientists ought to actively track the growth, migration, and gene/or protein profiles of cancer cell lines at specific PNs. This approach enables the identification of the most suitable range of PNs for experiments, guaranteeing consistent and precise results. Additionally, such efforts serve to minimize disparities and uphold the integrity of research. In this review, we have laid out recommendations for laboratories to overcome these PN discrepancies when working with cancer cell lines. 相似文献
38.
Darleen A. DeMason K. N. Chandra Sekhar Marilyn Harris 《American journal of botany》1989,76(9):1255-1265
Date seeds were sampled at regular intervals from pollination (March) to mature fruit (September) and processed for light microscopy and SDS-PAGE. Seed fresh weight rose until early June and then declined slightly through September due to a continuous decrease in water content. Cell wall formation started in May in the free nuclear endosperm and proceeded centripetally from the inner integument to the seed center. Wall thickening in each cell started in cell corners and showed a layered appearance with calcofluor white staining. It started in early June in the center of the seed and proceeded centrifugally such that the outer cells showed cell wall thickening in late June. Thickened cell walls were soft and PAS positive at inception, but staining disappeared and hardness increased during wall maturation. Cell elongation in the radial direction accompanied wall thickening. Protein body formation started after cell wall thickening and followed the same centrifugal developmental pattern. Mature protein bodies occurred in even the outermost cells by early July. No further structural changes occurred after this time. The high molecular weight storage proteins appeared in late June, which is when protein bodies had formed in all but the outer endosperm cells; however, these proteins did not appear simultaneously and minor changes in protein bands continued until maturation. α-Galactosidase activity was present in the developing endosperm and peaked at 13 wk after pollination. The data suggest that the thickened wall is deposited as a highly substituted galactomannan, but that most of the galactose side branches are clipped off presumably by α-galactosidase during cell wall polymerization. 相似文献
39.
Summary A new mutant strain,Aspergillus niger GS-III, showing resistance to manganese ions inhibition of citric acid fermentation on a sugarcane molasses containing medium was induced fromAspergillus niger KCU 520, a high citric acid-yielding strain. In submerged, surface or continuous cultures in the presence of manganese ions concentration upto 1.5 ppm the mutant strain yielded citric acid about 90 KgM–3 . The citric acid yield was comparable to that obtained with the parental strain KCU 520 in the absence of manganese ions, but it was atleast 3-fold higher than that obtained by the latter in the presence of manganese ions. The mutant strain immobilized in calcium alginate beads was used in combination with surface-stabilized cultures for about 36-days in a continuous flow horizontal fermenter without any apparent loss in citric acid productivity. These results indicate that the manganese-resistant mutant is stable and may be used in the presence of sufficient manganese ions concentration (1.5 ppm) in the fermentation medium. This capability of the mutant strainA. niger GS-III has been correlated with greatly reduced levels (about one-thirds) of the NADP+ -isocitric dehydrogenase, one of the control points for citric acid accumulation. 相似文献
40.
Mittal Chandra K. Harrell William B. Mehta Chander S. 《Molecular and cellular biochemistry》1995,149(1):263-265
This study was designed to evaluate thein vitro effects of transition heavy metal cations on activity of constitutive isoform of nitric oxide synthase (cNOS) in rat brain. NOS activity was determined in the cytosolic fractions of rat cerebral hemispheres by conversion of3H-L-arginine to3H-L-citrulline. Different concentrations of mercury (Hg2+), nickel (Ni2+), manganese (Mn2+), zinc (Zn2+), cadmium (Cd2+), lead (Pb2+) and calcium (Ca2+) were tested on NOS activity. While all the cations caused inhibition, there were differences in the apparent inhibition constants (Ki) among the cations. With the exception of calcium ion no other cation required preincubation with the enzyme preparation. These results indicate that while calcium ion modulate cNOS activity at regulatory site(s), inhibitory influence of toxic heavy metal cations may be exerted on the catalytic site(s) either by direct binding to it or by interfering with the electron transfer during catalysis. 相似文献