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排序方式: 共有848条查询结果,搜索用时 15 毫秒
1.
Sublethal stress of toxicants on organisms is generally measured through metabolic changes. The effects of three pesticides (endosulfan, malathion, and methyl parathion) on tissue lipid levels in the estuarine bivalve, Villorita cyprenoids var. cochinensis, have been measured. The reduction in lipid content was expressed as a function of the pesticide concentrations and the duration of the exposure periods (24, 48, 72, and 96 h). The results point to the existence of a direct relationship between the applied stress and the fall in the lipid content. The order of toxicity was endosulfan > malathion > methyl parathion. The depletion in lipid content observed may reflect an adaptive response of the organism to pesticide stress. Thus lipids in bivalves have been shown to be an important reserve material that may be utilized under stressed conditions as an energy source. © by John Wiley & Sons, Inc. 相似文献
2.
We have examined the patterns of expression of the major intermediate filament (IF) protein mRNAs during development of the hamster brain. Quantitative northern blotting was used to examine changes in the levels of mRNAs for the low, middle and high molecular weight neurofilament proteins (NF-L, NF-M, NF-H) as well as peripherin, vimentin and glial fibrillary acidic protein (GFAP). Total RNA was isolated from hamster brains at embryonic (E) days 12 and 14 and postnatal (P) days 1, 3, 5, 7, 9, 11, 13, 15, 20, 28 and 60-90 (adult), and probed with specific IF cDNAs. Northern blotting revealed that NF-L and NF-M mRNAs were present at very low levels in embryonic brain and that significant expression of these genes only occurred postnatally when the levels increased dramatically until P28 and then declined again in the adult. Increases in NF-H mRNA levels were somewhat delayed relative to those of NF-L and NF-M. NF-H mRNA was not seen at embryonic stages and was expressed at very low levels prior to P9; after that time the levels increased rapidly until P28 and then declined in the adult. Two of the type III IF genes, peripherin and vimentin, followed a pattern of expression opposite that of the NF genes. Both peripherin and vimentin mRNAs were present in embryonic brain and were expressed at higher levels during early postnatal stages than at later times. The magnitude and rate of reduction in vimentin gene expression in the postnatal interval was much greater than that of peripherin. GFAP mRNA levels were extremely low prior to P9 after which a robust increase occurred, followed by a decline in the adult. We discuss the implication of the dramatic changes in IF isotype expression in brain to the pathways of both neuronal and glial development in vivo. 相似文献
3.
Biji Bahuleyan Ankamma Rao Ari George Chacko Roy Thomas Daniel 《Journal of clinical neuroscience》2007,14(9):895-898
Chiari I malformation (CM) associated with a cervico-thoracic syrinx due to supracerebellar arachnoid cyst has not been reported in the literature. We report such a case, managed by fenestration of the arachnoid cyst and foramen magnum decompression (FMD), aiming to reduce the inferiorly directed pressure on the cerebellum and eliminate the craniospinal pressure dissociation respectively. Imaging done post-operatively showed upward displacement of the cerebellar tonsils with a decompressed craniovertebral junction and disappearance of the syrinx. 相似文献
4.
Comparison of the Amplicor HIV-1 monitor test and the nucleic acid sequence-based amplification assay for quantitation of human immunodeficiency virus RNA in plasma, serum, and plasma subjected to freeze-thaw cycles. 总被引:6,自引:5,他引:1
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B P Griffith M O Rigsby R B Garner M M Gordon T M Chacko 《Journal of clinical microbiology》1997,35(12):3288-3291
The Amplicor HIV-1 Monitor test was compared to the nucleic acid sequence-based amplification (Nasba) assay system for the quantitation of human immunodeficiency virus (HIV) RNA in three different types of clinical samples: plasma, serum, and plasma subjected to freeze-and-thaw cycles. Each assay detected HIV RNA in the same 73 (90%) of 81 samples tested, and the quantitative results obtained with the two assays were significantly correlated. Both assays detected higher RNA levels in patients with CD4+ cell counts lower than 200 cells/mm3 than in patients with CD4+ cell counts higher than 200 cells/mm3. In addition, RNA levels in plasma higher than 5 logs predicted higher numbers of clinical events than did RNA levels in plasma lower than 5 logs. Quantitation of HIV RNA in paired plasma and serum samples showed lower HIV RNA content in serum than in the paired plasma sample, with mean differences between HIV RNA contents of plasma and serum of 0.54 and 0.28 log RNA copy/ml by the Nasba assay and the Amplicor HIV-1 Monitor assay, respectively. No significant loss of HIV RNA was detected with either assay in plasma samples subjected to multiple freeze-and-thaw cycles. These studies demonstrate that the Nasba and Amplicor assays perform similarly with plasma and serum samples. Further, the results indicate that freeze-and-thaw cycles do not result in significant loss of detectable HIV RNA. 相似文献
5.
6.
A. V. Meera S. Sen P. Raghupathy D. Walter M. Chandy H. Krishnaswami J. Chacko N. Zachariah K. E. Mammen 《Pediatric surgery international》1995,10(5-6):389-390
We present two children with massive bleeding into the serous body cavities accompanied by intractable consumption coagulopathy. One had a large spleen palpable at admission, the other developed progressive splenomegaly while in hospital. Neither child had any external evidence of angiomatous lesions. A splenic hemangioma was suspected clinically and on abdominal ultrasound; the diagnosis was confirmed at laparotomy. Splenectomy resulted in a prompt cure in both cases. 相似文献
7.
Wymbs Frances Doctoroff Greta L. Chacko Anil Sternheim Gillian 《Prevention science》2021,22(7):866-879
Prevention Science - The impact of evidence-based parenting health promotion programs is threatened by limited enrollment and attendance. We used a discrete choice experiment (DCE) to examine how... 相似文献
8.
Regulation of actomyosin and contraction in smooth muscle 总被引:4,自引:1,他引:3
Summary Unlike striated muscle cells, smooth muscle cells do not have an organized sarcomeric structure. However, all smooth muscle cells contain the contractile proteins, myosin, actin, and tropomyosin. Polymorphism of the myosin heavy chain exists in smooth muscle cells. Two myosin heavy chain (MHC) isoforms, SM1 (204 kDa) and SM2 (200 kDa), are present in smooth muscle cells; however, their ratios vary in smooth muscles from different sources. The hypertrophy of the urinary bladder induced by partial outlet obstruction in rabbits is associated with an alteration of the SM1-to-SM2 ratio from 1:3 to 1:1. Both heavy chains react with polyclonal antibody against smooth muscle myosin; however, antibody prepared against a peptide from the C-terminal region of the SM2 heavy chain cross-reacts only with the SM2 heavy chain. Removal of the obstruction reverses the bladder to normal mass with a concomitant change in the SM1-to-SM2 ratio back to 1:3. The expression of the SM1 mRNA is increased in response to obstruction-induced hypertrophy, and it also returns to normal upon removal of the obstruction. Urinary bladder smooth muscle contains predominantly -actin. Obstruction-induced hypertrophy of the bladder smooth muscle is associated with an increase in the -actin at both protein and mRNA levels. The -non-muscle actin is decreased and the -smooth muscle actin is unchanged in response to obstruction-induced bladder hypertrophy.Contraction of all smooth muscles involves similar mechanisms. This review describes our current understanding of the mechanisms regulating contraction of the smooth muscle of the urinary bladder.This work was supported in part by NIH grants HL 22246, DK 47514 and DK 39740 相似文献
9.
Williams B Chacko PT 《The Canadian journal of radiography, radiotherapy, nuclear medicine》1983,14(3):96-101
Because of a very low technologist productivity in their Radiology Department, the authors describe a Productive Point System they developed and implemented to solve this personnel problem. After establishing the average time required to perform all exams, point credits (one point for every ten minutes utilized) were assigned to each exam performed, thereby determining an index of production. A Productive Index of 80% was considered realistic and was the equivalent of 192 points for a 40-hour work week. From 1975 to 1978 personal productivity increased from 79% to 113%. This resulted in an average yearly fiscal savings of over $20,000.00 for this three-year period. There was also a significant improvement in exam efficiency and quality, job attitude, personnel morale, and public relations. This program was highly successful because technologist acceptance and cooperation was complete, and this occurred mainly because the system supports the normal occupational goals and expectations of technologists. 相似文献
10.
Gujral S Abrams P Donovan JL Neal DE Brookes ST Chacko KN Wright MJ Timoney AG Peters TJ 《The Journal of urology》2000,164(1):59-64
PURPOSE: We assessed the effectiveness of laser therapy versus transurethral prostatic resection in men with symptomatic chronic urinary retention secondary to benign prostatic enlargement. MATERIALS AND METHODS: This trial was multicenter, pragmatic and randomized. Analysis was done by intent to treat. Laser therapy involved neodymium:YAG noncontact visual prostate ablation, while transurethral prostatic resection was performed by standard electroresection. Patients were included in our study if they reported moderate to severe lower urinary tract symptoms with an International Prostate Symptom Score (I-PSS) of 8 or more, benign prostatic enlargement and a persistent post-void residual urine volume of more than 300 ml. Followup was 7.5 months. Primary outcome measures included the I-PSS, I-PSS quality of life score, maximum urinary flow and post-void residual urine volume. Secondary outcome measures included treatment failure, complications, hospital stay and catheterization time. RESULTS: A total of 82 patients agreed to be randomized to receive laser therapy (38) or transurethral prostatic resection (44). There were significant improvements in all primary outcomes in each group from randomization to followup. Transurethral prostatic resection was significantly better than laser therapy for I-PSS and maximum urinary flow values (p = 0.035 and 0.029, respectively) but there were no differences in post-void residual urine volume and I-PSS quality of life score between the groups. We noted significantly more treatment failures with laser therapy than resection (8 versus 0, p = 0.0014), although only 3 patients required resection after laser therapy because of persistent symptoms. In addition, hospital stay after resection was 2-fold that after laser therapy (ratio of geometric means 2.01, 95% confidence interval 1.54 to 2.61, p <0.0001). However, time to catheter removal was 9 times longer in the laser therapy group (p <0. 0001). Complication rates were significantly higher for transurethral prostatic resection (chi-square 5.05, 1 df, p = 0.025). CONCLUSIONS: Transurethral prostatic resection is more effective than laser ablation in men with chronic urinary retention in terms of symptom score, maximum urinary flow and failure. However, men who underwent resection had significantly more treatment complications and were hospitalized longer than those who received laser therapy. This finding implies that laser ablation therapy may have a role in patients at higher risk who are willing to accept a lower level of effectiveness in exchange for decreased complication rates and hospital stay. 相似文献