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71.
72.
Bartholomew J Reichart J Mundy R Recktenwald J Keyser S Riddle M Kuruvilla H 《Purinergic signalling》2008,4(2):171-181
Guanosine 5'-triphosphate (GTP) is a chemorepellent in Tetrahymena thermophila that has been shown to stimulate cell division as well as ciliary reversal. Previous studies have proposed that GTP avoidance is linked to a receptor-mediated, calcium-based depolarization. However, the intracellular mechanisms involved in GTP avoidance have not been previously documented. In this study, we examine the hypothesis that GTP signals through a tyrosine kinase pathway in T. thermophila. Using behavioral assays, enzyme immunosorbent assays, Western blotting, and immunofluorescence, we present data that implicate a tyrosine kinase, phospholipase C, intracellular calcium, nitric oxide synthase (NOS) and guanylyl cyclase in GTP signaling. The tyrosine kinase inhibitor genistein eliminates GTP avoidance in Tetrahymena in behavioral assays. Similarly, pharmacological inhibitors of phospholipase C, NOS, and guanylyl cyclase all eliminated Tetrahymena avoidance to GTP. Immunofluorescence data shows evidence of tyrosine kinase activity in the cilia, suggesting that this enzyme activity could be directly involved in ciliary reversal. 相似文献
73.
Effect of somatostatin on gastrointestinal contractility in Schistosoma mansoni infected mice 总被引:3,自引:0,他引:3
De Man JG Chatterjee S De Winter BY Vrolix G Van Marck EA Herman AG Pelckmans PA 《International journal for parasitology》2002,32(10):1309-1320
Schistosoma mansoni infection induces severe gastrointestinal motility disturbances which are characterised by hyperactivity of intestinal muscle, abdominal pain, diarrhoea, vomiting and nausea. During schistosomiasis, the neuropeptide somatostatin is generated within inflammatory granulomas. However, somatostatin is also an important inhibitory modulator of gastrointestinal motility. In the present study, we have investigated the potential of somatostatin to reduce schistosomiasis-induced hyperactivity of gastrointestinal smooth muscle. Organ bath experiments were performed to study the contractility of isolated smooth muscle strips of intestine from control mice and from mice that were infected with S. mansoni for 2, 4, 8 and 16 weeks. Electrical field stimulation (0.5-8 Hz) of enteric nerves induced frequency-dependent neurogenic contractions of cholinergic origin in all regions of the small intestine. Somatostatin (0.1-1 microM) concentration-dependently inhibited the contractions to enteric nerve stimulation in the small intestine from uninfected control mice and from acutely S. mansoni infected mice (2 and 4 weeks of infection). After 8 weeks of infection with S. mansoni, this inhibitory effect of somatostatin was less pronounced and after 16 weeks of infection it was completely abolished. Histology demonstrated that chronic infection of mice with S. mansoni was associated with significant alterations in the musculature of the small intestine. These alterations may be associated with physiological changes in the responsiveness to somatostatin and suggest that the somatostatin neuroregulatory circuit of enteric neurotransmission in the small intestine is disturbed during chronic schistosomiasis mansoni. 相似文献
74.
Shyama Sidique Sergey A. Shiryaev Boris I. Ratnikov Ananda Herath Ying Su Alex Y. Strongin Nicholas D.P. Cosford 《Bioorganic & medicinal chemistry letters》2009,19(19):5773-5777
West Nile Virus (WNV) is a potentially deadly mosquito-borne flavivirus which has spread rapidly throughout the world. Currently there is no effective vaccine against flaviviral infections. We previously reported the identification of pyrazole ester derivatives as allosteric inhibitors of WNV NS2B-NS3 proteinase. These compounds degrade rapidly in pH 8 buffer with a half life of 1–2 h. We now report the design, synthesis and in vitro evaluation of pyrazole derivatives that are inhibitors of WNV NS2B-NS3 proteinase with greatly improved stability in the assay medium. 相似文献
75.
Revonsuo proposes an evolutionary theory of dreaming in which dreams allow an individual to prepare for real world threats in the safety of the virtual setting of the dream world. Based upon previous work examining the dreams of video game players, it was hypothesized that high-end gamers would experience fewer threat simulation dreams because of frequent threat resolution rehearsal during game play. Subjects were asked to report a night before dream and fill out surveys regarding their gaming history, media use, and dream experiences. Using a factor analysis, support for the main hypothesis was found. Individuals with a history of game play experienced fewer threat severity variables in their dreams. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
76.
Many recent high throughput technologies have enabled large-scale discoveries of new phosphorylation sites and phosphoproteins. Although they have provided a number of insights into protein phosphorylation and the related processes, an inclusive analysis on the nature of phosphorylated sites in proteins is currently lacking. We have therefore analyzed the occurrence and occupancy of phosphorylated sites (~100,281) in a large set of eukaryotic proteins (~22,995). Phosphorylation probability was found to be much higher in both the termini of protein sequences and this is much pronounced in transmembrane proteins. A large proportion (51.3%) of occupied sites had a nearby phosphorylation within a distance of 10 amino acids; however, this proportion is very high compared to the expected one (16.9%). The distribution of phosphorylated sites in proteins showed a strong deviation from the expected maximum randomness. An analysis of phosphorylation motifs indicated that just 40 motifs and a much lower number of associated kinases might account for nearly 50% of the known phosphorylations in eukaryotic proteins. Our results provide a broad picture of the phosphorylation sites in eukaryotic proteins. 相似文献
77.
Pretty Mary Abraham Korah P Kuruvilla Jobin Mathew Anitha Malat Shilpa Joy CS Paulose 《Journal of biomedical science》2010,17(1):78
Diabetes and stress stimulate hippocampal 5-HT synthesis, metabolism and release. The present study was carried out to find
the effects of insulin, Aegle marmelose alone and in combination with pyridoxine on the hippocampal 5-HT, 5-HT2A receptor subtype, gene expression studies on 5-HT2A, 5-HTT, INSR, immunohistochemical studies and elevated plus maze in streptozotocin induced diabetic rats. 5-HT content showed
a significant decrease (p < 0.001) and a significant increase (p < 0.001) in 5-HIAA in hippocampus of diabetic rats compared to control. 5-HT receptor binding parameters Bmax and Kd showed a significant decrease (p < 0.001) whereas 5-HT2A receptor binding parameters Bmax showed a significant decrease (p < 0.001) with a significant increase (p < 0.05) in Kd in hippocampus of diabetic rats compared to control. Gene expression studies of 5-HT2A, 5-HTT and INSR in hippocampus showed a significant down regulation (p < 0.001) in diabetic rats compared to control. Pyridoxine treated in combination with insulin and A. marmelose to diabetic rats reversed the 5-HT content, Bmax , Kd of 5-HT, 5-HT2A and gene expression of 5-HT2A, 5-HTT and INSR in hippocampus to near control. The gene expression of 5-HT2A and 5-HTT were confirmed by immunohistochemical studies. Behavioural studies using elevated plus maze showed that serotonin
through its transporter significantly increased (p < 0.001) anxiety-related traits in diabetic rats which were corrected by
combination therapy. Our results suggest that pyridoxine treated in combination with insulin and A. marmelose has a role in the regulation of insulin synthesis and release, normalising diabetic related stress and anxiety through hippocampal
serotonergic function. This has clinical significance in the management of diabetes. 相似文献
78.
OBJECTIVE: To correlate the cytomorphologic spectrum of giant cell tumor of tendon sheath (GCTTS) with clinical and histologic findings and determine key features helpful in preoperative diagnosis. STUDY DESIGN: Retrospective analysis was done on 48 cases diagnosed cytologically over 9 years. Cases were divided into 2 groups: in group 1 cytology and histology were available (12), and in group 2 cytology alone was available (36). Cytomorphologic features were correlated with clinical and histologic findings. RESULTS: Patients ranged in age from 11 to 60 years, with more women. Small joint involvement was seen in all cases except 1, with upper limb involvement in most cases. Recurrence occurred in 3 cases. Aspiration smears in all cases showed high cellularity, multinucleated osteoclastic type of giant cells and stromal cells. Other features seen less frequently were cytoplasmic granules and vacuoles, nuclear grooves, inclusions, budding, focal mild pleomorphism, hemosiderin-laden macrophages and foam cells. Mitosis and necrosis were absent. Cytologic features were classified as constant when present in all cases and variable when present occasionally. CONCLUSION: The constant cytologic features when combined with clinical and radiologic details are sufficiently distinctive of GCTTS. Fine needle aspiration cytology can be used in early, accurate preoperative diagnosis. 相似文献
79.
Fontes AM Kashima S Bonfim-Silva R Azevedo R Abraham KJ Albuquerque SR Bordin JO Júnior DM Covas DT 《Genetics and molecular biology》2011,34(4):539-545
Complement receptor 1 (CR1) gene polymorphisms that are associated with Knops blood group antigens may influence the binding of Plasmodium parasites to erythrocytes, thereby affecting susceptibility to malaria. The aim of this study was to evaluate the genotype and allele and haplotype frequencies of single-nucleotide polymorphisms (SNPs) of Knops blood group antigens and examine their association with susceptibility to malaria in an endemic area of Brazil. One hundred and twenty-six individuals from the Brazilian Amazon were studied. The CR1-genomic fragment was amplified by PCR and six SNPs and haplotypes were identified after DNA sequence analysis. Allele and haplotype frequencies revealed that the Kn(b) allele and H8 haplotype were possibly associated with susceptibility to Plasmodium falciparum. The odds ratios were reasonably high, suggesting a potentially important association between two Knops blood antigens (Kn(b) and KAM(+)) that confer susceptibility to P. falciparum in individuals from the Brazilian Amazon. 相似文献
80.
BACKGROUND: Follicular carcinoma of the thyroid in association with hyperthyroidism is rare. The malignant lesion may remain occult for a long time. Certain clinical and cytologic features may be helpful in raising the alarm. CASE: An elderly male with a history of occupational exposure to X rays, long-standing toxic multinodular goiter and clinical hyperthyroidism presented with a rapidly enlarging mass in the neck. Cytologic smears showed a prominent microfollicular pattern, scanty colloid, anisonucleosis and nuclear overlapping. The noteworthy feature was the presence of marginal vacuoles. The cytologic diagnosis of follicular neoplasm with highly suggestive malignancy was made. Subsequently, multiple pulmonary nodules provided radiologic evidence of possible metastatic spread. CONCLUSION: This case report demonstrates the rare association of follicular carcinoma of the thyroid with hyperthyroidism and analyzes certain high-risk clinical and cytologic features to be considered in the follow-up of long-standing hyperfunctioning multinodular goiter. 相似文献