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81.
Benito N Moreno A Filella X Miró JM González J Pumarola T Valls ME Luna M García F Rañó A Torres A Gatell JM 《Clinical and diagnostic laboratory immunology》2004,11(3):608-614
We analyzed the characteristics of the inflammatory response occurring in blood during pulmonary infections in human immunodeficiency virus (HIV)-infected patients. A prospective study of consecutive hospital admissions of HIV-infected patients with new-onset radiologic pulmonary infiltrates was carried out in a tertiary university hospital from April 1998 to May 2001. Plasma cyclic AMP receptor protein (CRP), interleukin 1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor alpha (TNF-alpha) levels were determined at the time of admission and 4, 5, and 6 days later. Patients were included in a protocol addressed to study etiology and outcome of disease. A total of 249 episodes of infection were included, with the main diagnoses being bacterial pneumonia (BP) (118 episodes), Pneumocystis carinii pneumonia (PCP) (41 episodes), and mycobacteriosis (36 episodes). For these three patient groups, at the time of admission the median CRP and cytokine levels were as follows: CRP, 10.2, 3.8 and 5 mg/dl, respectively (P = 0.0001); IL-8, 19, 3, and 2.9 pg/ml (P = 0.045); and TNF-alpha, 46.4, 44, and 75 pg/ml, respectively (P = 0.029). There were no significant differences in levels of IL-1beta, IL-6, or IL-10 among the patient groups. A total of 23 patients died. At the time of admission, HIV-infected patients with BP had higher plasma CRP and IL-8 levels than did PCP and mycobacteriosis patients. TNF-alpha levels were higher in patients with mycobacteriosis. An elevated IL-8 level (>61 pg/ml) at the time of admission was an independent factor associated with higher mortality (odds ratio, 12; 95% confidence interval, 1.2 to 235.5). 相似文献
82.
Calcium events in smooth muscles and their interstitial cells; physiological roles of sparks 总被引:2,自引:1,他引:2
Tom B. Bolton 《The Journal of physiology》2006,570(1):5-11
The observation of spontaneous sporadic releases of packets of stored calcium made 20 years ago has opened up a number of new concepts in smooth muscle physiology: (1) the calcium release sites are ryanodine and inositol 1,4,5-trisphosphate (IP3 ) receptor channels which contribute to cell-wide increases in [Ca2 + ]i in response to cell depolarization, activation of IP3 -generating receptors, or other stimuli; (2) changes in [Ca2 + ]i act back on the cell membrane to activate or modulate K+ , Cl− and cation channel activity so affecting contraction, in arterial smooth muscle for example affecting blood pressure; (3) IP3 production is voltage dependent and is believed to contribute to pacemaker potentials and to refractory periods which control the rhythmical motility of many hollow organs. Most smooth muscle tissues contain interstitial cells (ICs) in addition to contractile smooth muscle cells (SMCs). The interactions of these internal mechanisms, and in turn the interactions of SMCs and ICs in various smooth muscle tissues, are major factors in determining the unique physiological profiles of individual smooth muscles. 相似文献
83.
Stehle Robert Lionne Corinne Travers Franck Barman Tom 《Journal of muscle research and cell motility》1998,19(4):381-392
We have exploited solvent perturbation to probe the coupling of Ca2+ and rigor activation of the ATPase of myofibrils from rabbit psoas. Three techniques were used: overall myofibrillar ATPases
by the rapid-flow quench method; kinetics of the interaction of ATP with myofibrils by fluorescence stopped-flow; and myofibrillar
shortening by optical microscopy. Because of its extensive use with muscle systems, ranging from myosin subfragment-1 to muscle
fibres, we chose 40% ethylene glycol as the relaxing agent. At 4°C, the glycol had little effect on the myofibrillar ATPase
at low [Ca2+], but at high [Ca2+] the activity was reduced 50-fold, close to the level found under relaxing conditions, and there was no shortening. However,
the ATPase of chemically cross-linked myofibrils (permanently activated even without Ca2+) was reduced only 3–4-fold. The lesser reduction of the ATPase of permanently activated myofibrils was also observed in single
turnover experiments in which activation occurs by a few heads in the rigor state activating the remaining heads. The addition
of ADP, which also promotes strong head-thin filament interactions, also activated the ATPase but only in the presence of
Ca2+. Further experiments revealed that in 40% ethylene glycol, Ca2+ does initiate shortening but only with the aid of strong interactions and at temperatures above 15°C. This confirms that
in the organized and intact myofibril, Ca2+ and rigor activation are coupled, as proposed previously for regulated actomyosin subfragment-1.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
84.
Quality assurance of a helical tomotherapy machine 总被引:2,自引:0,他引:2
Fenwick JD Tomé WA Jaradat HA Hui SK James JA Balog JP DeSouza CN Lucas DB Olivera GH Mackie TR Paliwal BR 《Physics in medicine and biology》2004,49(13):2933-2953
Helical tomotherapy has been developed at the University of Wisconsin, and 'Hi-Art II' clinical machines are now commercially manufactured. At the core of each machine lies a ring-gantry-mounted short linear accelerator which generates x-rays that are collimated into a fan beam of intensity-modulated radiation by a binary multileaf, the modulation being variable with gantry angle. Patients are treated lying on a couch which is translated continuously through the bore of the machine as the gantry rotates. Highly conformal dose-distributions can be delivered using this technique, which is the therapy equivalent of spiral computed tomography. The approach requires synchrony of gantry rotation, couch translation, accelerator pulsing and the opening and closing of the leaves of the binary multileaf collimator used to modulate the radiation beam. In the course of clinically implementing helical tomotherapy, we have developed a quality assurance (QA) system for our machine. The system is analogous to that recommended for conventional clinical linear accelerator QA by AAPM Task Group 40 but contains some novel components, reflecting differences between the Hi-Art devices and conventional clinical accelerators. Here the design and dosimetric characteristics of Hi-Art machines are summarized and the QA system is set out along with experimental details of its implementation. Connections between this machine-based QA work, pre-treatment patient-specific delivery QA and fraction-by-fraction dose verification are discussed. 相似文献
85.
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87.
Transfer of the active form of transforming growth factor-beta 1 gene to newborn rat lung induces changes consistent with bronchopulmonary dysplasia 总被引:7,自引:0,他引:7
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Gauldie J Galt T Bonniaud P Robbins C Kelly M Warburton D 《The American journal of pathology》2003,163(6):2575-2584
Bronchopulmonary dysplasia is a chronic lung disease of premature human infancy that shows pathological features comprising varying sized areas of interstitial fibrosis in association with distorted large alveolar spaces. We have previously shown that transfer of active transforming growth factor (TGF)-beta 1 (AdTGF beta 1(223/225)) genes by adenovirus vector to embryonic lungs results in inhibition of branching morphogenesis and primitive peripheral lung development, whereas transfer to adult lungs results in progressive interstitial fibrosis. Herein we show that transfer of TGF-beta1 to newborn rat pups results in patchy areas of interstitial fibrosis developing throughout a period of 28 days after transfer. These areas of fibrosis appear alongside areas of enlarged alveolar spaces similar to the prealveoli seen at birth, suggesting that postnatal lung development and alveolarization has been inhibited. In rats treated with AdTGF beta 1(223/225), enlarged alveolar spaces were evident by day 21, and by 28 days, the mean alveolar cord length was nearly twice that in control vector or untreated rats. Hydroxyproline measurements confirmed the presence of fibrosis. These data suggest that overexpression of TGF-beta 1 during the critical period of postnatal rat lung alveolarization gives rise to pathological, biochemical, and morphological changes consistent with those seen in human bronchopulmonary dysplasia, thus inferring a pathogenic role for TGF-beta in this disorder. 相似文献
88.
Voluntary HIV counseling and testing: experience among the sexually active population in Bangui,Central African Republic 总被引:4,自引:0,他引:4
Grésenguet G Séhonou J Bassirou B Longo Jde D Malkin JE Brogan T Bélec L 《Journal of acquired immune deficiency syndromes (1999)》2002,31(1):106-114
OBJECTIVES: In July 1997, the National Reference Center for Sexually Transmitted Diseases of Bangui, Central African Republic (CAR), was expanded by the creation of an anonymous and voluntary counseling and testing (VCT) unit for HIV infection, the Anonymous Surveillance Unit (Unité de Dépistage Anonyme [UDA]). The goal of the UDA was to initiate and promote voluntary HIV testing in the general adult population of Bangui. We carried out an observational and comprehensive survey over a 4-year period to document and analyze the experience of VCT in the UDA, with special attention to risk factors associated with HIV infection. METHODS: All clients for VCT were given adequate pretest counseling by trained counselors focused on knowledge about HIV infection and sexually transmitted infections, individual risks of acquiring HIV, and anticipation of the client's attitude about test results. After consent was obtained, a blood sample was drawn and tested for HIV by two ELISAs in parallel. The client paid a standard cost of $1.20 at the initial visit. After a week, test results were given to the client during the posttest visit, at which time HIV-seropositive individuals received emotional support and were referred to specific social or medical structures. Seronegative clients received reinforcement of prevention messages and were asked to come back for serologic follow-up free of charge after 3 (M3) and 12 (M12) months. RESULTS: From July 1997 to March 2001, 5686 individuals aged 14 to 65 years (mean age, 27 years) had an initial visit for VCT (V1). Peaks of UDA visitation (250-450 clients) were observed on the annual AIDS Day in the CAR, at which time HIV serologic testing was offered free of charge. A total of 5060 (89%) clients came back for a second visit (V2) to receive test results. Among those, 18.3% were infected with HIV type 1. Multivariate analysis of risk factors demonstrated marked association of HIV seropositivity with age, female gender, widowed/divorced women, poor or low education level, occupations such as civil servants or merchants, presence of symptoms of sexually transmitted infections, and lack of systematic condom use. Single young women were at higher risk for HIV infection compared with men of the same age (OR = 7.7 for women aged 15-24 years, 95% CI: 4.0-14.0; OR = 2.8 for women aged 25-34 years, 95% CI: 1.7-4.5). Widowed women older than 44 years of age were more likely to be HIV-seropositive than men (OR = 10.0; 95% CI: 1.7-83.6). A total of 885 (21%) HIV-seronegative individuals returned for follow-up at 3 months (M3; 0.45% rate of seroconversion). Seventy-nine (9%) individuals returned at 12 months (M12), without any new cases of HIV infection. HIV-negative clients consulting at M3 and M12 showed a significant reduction in unprotected intercourse with occasional sexual partners. CONCLUSION: This experience demonstrates that VCT for HIV infection is feasible in Central Africa. 相似文献
89.
A gene for autosomal recessive limb-girdle muscular dystrophy maps to chromosome 2p 总被引:10,自引:3,他引:10
Bashlr Rumaisa; Strachan Tom; Keers Sharon; Stephenson Anthea; Mahjneh Ibrahim; Marconi Giamplero; Nashef Lina; Bushby Kate M. D. 《Human molecular genetics》1994,3(3):455-457
The limb-girdle muscular dystrophies are a clinically and geneticallyheterogeneous group of disorders. We have ostudied two largeinbred families of different ethnic origin and excluded linkageto LGMD2 on chromosome 15q and SCARMD on chromosome 13. Proceedingto a genomic linkage search, we have now identified linkageto markers D2S134 and D2S136 on chromosome 2p (maximum lod score3.57 at zero recombination). The phenotype in the two familieswas similar, with onset in the pelvic girdle musculature inthe late teens and usually relatively slow progression. Thiswork Identifies a second locus for autosomal recessive limb-girdlemuscular dystrophy. 相似文献