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941.
The human cytomegalovirus (HCMV) major immediate-early promoter (MIEP) is one of the first promoters to activate upon infection. To examine HCMV MIEP tissue-specific expression, transgenic mice were established containing the lacZ gene regulated by the MIEP (nucleotides -670 to +54). In the transgenic mice, lacZ expression was demonstrated in 19 of 29 tissues tested by histochemical and immunochemical analyses. These tissues included brain, eye, spinal cord, esophagus, stomach, pancreas, kidney, bladder, testis, ovary, spleen, salivary gland, thymus, bone marrow, skin, cartilage, and cardiac, striated and smooth muscles. Although expression was observed in multiple organs, promoter activity was restricted to specific cell types. The cell types which demonstrated HCMV MIEP expression included retinal cells of the eye, ductile cells of the salivary gland, exocrine cells of the pancreas, mucosal cells of the stomach and intestine, neuronal cells of the brain, muscle fibers, thecal cells of the corpus luteum, and Leydig and sperm cells of the testis. These observations indicate that the HCMV MIEP is not a pan-specific promoter and that the majority of expressing tissues correlate with tissues naturally infected by the virus in the human host.  相似文献   
942.
A 15-year-old boy, whose history revealed an unremarkable pregnancy, birth and neonatal period and who had shown a normal motor and mental development, presented at the hospital with deterioration of cognitive functions since the age of 7. He was bedridden with manifest ataxia involving all limbs, anisocoria and a sluggish to absent pupil reaction to light. Syphilis serology was positive with a Venereal Disease Research Laboratory (VDRL) titer of 1:256 and a Treponema pallidum Haemagglutination Assay (TPHA) titer of 1:163840. Cerebrospinal fluid (CSF) protein concentration was 55 mg/dl and CSF-leucocyte count was 14/mm3 (85% mononuclear cells). CSF-VDRL-titer was 1:16. A diagnosis of congenitally acquired dementia paralytica was made, since the boy's parents' clinical exam and serology results were suggestive for latent syphilis. Although cognition was still very much deteriorated five months following penicillin treatment, clinical examination revealed partial recuperation. Screening for syphilis should be part of routine testing in every subject presenting with cognitive deterioration, regardless of age.  相似文献   
943.
BACKGROUND: The exercise-induced rise in arterial potassium concentration ([K+]a) may contribute to exercise hyperpnea and could play a role in exertional fatigue. This study was designed to determine whether the exercise-induced rise in [K+]a is altered in patients with chronic heart failure (CHF) and whether physical training affects K+ homeostasis. METHODS AND RESULTS: We evaluated 10 subjects with CHF (ejection fraction, 23 +/- 3.9%) and 10 subjects with normal left ventricular function (NLVF) who had undergone previous coronary artery graft surgery (ejection fraction, 63 +/- 8.6%). Subjects performed an incremental cycle ergometer exercise test before and after a physical training or detraining program. Changes in [K+]a and ventilation (VE) during exercise were closely related in both groups. Subjects with CHF did less absolute work and had reduced maximal oxygen consumption (VO2max) compared with subjects with NLVF (P < .01). Exercise-induced rises in [K+]a, VE, norepinephrine, lactate, and heart rate were greater at matched absolute work rates in subjects with CHF than in subjects with NLVF (P < .01). However, when the rise in [K+]a was plotted against percentage of VO2max to match for relative submaximal effort, there were no differences between the two groups. Physical training resulted in reduced exercise-induced hyperkalemia at matched submaximal work rates in both groups (P < .01) despite no associated change in the concentration of arterial catecholamines. At maximal exercise when trained, peak increases in [K+]a were unaltered, but peak concentrations of catecholamines were raised (P < .05). The decrease in VE at submaximal work rates after training was not significant with this incremental exercise protocol, but both groups had an increased peak VE when trained (P < .01). CONCLUSIONS: Exercise-induced rises in [K+]a, catecholamines, and VE are greater at submaximal work rates in subjects with CHF than in subjects with NLVF. Physical training reduces the exercise-induced rise in [K+]a but does not significantly decrease VE during submaximal exercise with this incremental cycle ergometry protocol. The reduction in exercise-induced hyperkalemia after training is not the result of altered concentrations of arterial catecholamines. The pathophysiological significance of the increased exercise-induced hyperkalemia in CHF and the mechanisms of improved K+ homeostasis with training have yet to be established.  相似文献   
944.
This study demonstrated an immediate and short-lasting endothelin-1 release in the circulation of patients with severe chronic congestive heart failure during isometric handgrip exercise, but not in normal subjects. Our data suggest that endothelin-1 levels may increase transiently during daily physical activity, thus contributing to progressive deterioration of left ventricular function.  相似文献   
945.
946.
947.
OBJECTIVE: To evaluate CVVH (Continuous Veno-Venous Hemofiltration) as acute renal replacement treatment in postoperative care of liver transplantation. DESIGN: Retrospective study. SETTING: Intensive Care Unit, year 1995. PATIENTS: 86 OLT performed in 1995, 11 of them underwent acute renal replacement treatment. In the same period, in the ICU were admitted 237 patients, and 20 underwent acute renal replacement treatment (control group). Evaluation with SOFA (Sepsis-related Organ Failure Assessment) score. INTERVENTION: CVVH performed heparin free, pump system, polyamide or polysulphone 0.6 mq membrane hemofilter device, blood flow 150-200 ml/min, UF rate 1000-1200 ml/h, clearance 16-20 ml/min. MEASUREMENTS: Coagulation monitoring (PT as INR, PTT, fibrinogen, antithrombin III, d-dimer, platelet count) was performed 3 times a day or on variation of the clinical conditions. RESULTS: SOFA score did not differ between the two groups. Mortality was higher in the patients treated with CVVH. CVVH was performed from 16 to 18 hrs/day for 9.90 +/- 2.33 days. Three patients developed clinical bleeding before CVVH, 3 during CVVH but 1 of them underwent repeated surgical procedures. CONCLUSIONS: We cannot demonstrate that CVVH doesn't affect bleeding, but we can say that, for the complexity of the post OLT patients, CVVH can be the treatment of choice in case of renal replacement treatment.  相似文献   
948.
Studies of invasive breast cancers consistently identify a subset of tumors without telomerase activity, compromising its utility as a tumor marker. Telomerase-negative tumors may represent a biologically different subset, or the result could be attributed to assay imperfections. To resolve this issue, we tested 105 invasive breast cancers for telomerase activity and found that 23 (22%) tumors were telomerase negative. Careful histological confirmation of an adjacent cryosection and/or microdissection of pure tumor cells reduced this number to 5 (5%). Thus, truly telomerase-negative invasive breast cancers are rare, making this enzyme a potentially very useful tumor marker in breast cancer.  相似文献   
949.
A new species and additional host records for 4 other species of quiescent deutonymphs (hypopi) of mites of the family Hypoderatidae are described from the subcutaneous adipose tissues of a roseate spoonbill, Ajaia ajaja L., in Florida. The hypopus of Phalacrodectes parvus n. sp. most closely resembles that of P. platalea Pence & Duncan from the African spoonbill, Platalea alba Scopali, in idiosomatic chaetotaxy and structure of the genital apparatus. It differs from this and other species of the genus in the shape of the idiosoma, pattern and density of idiosomatic sclerotization, the unique posterior extension of secondary sclerotization from the perigenital area, large size and more posterior location of genital seta gm, and small size and sharp-tipped spinelike structure of seta hT on tibia II. In addition to the new species, this roseate spoonbill also was infected with P. whartoni Fain and 3 other less common species of hypoderatid deutonymphs. A key to the deutonymphs of species in the genus Phalacrodectes is presented.  相似文献   
950.
A lightweight, robust P2P system to handle flash crowds   总被引:4,自引:0,他引:4  
An Internet flash crowd (also known as hot spots) is a phenomenon that results from a sudden, unpredicted increase in an on-line object's popularity. Currently, there is no efficient means within the Internet to deliver Web objects scalably under hot spot conditions to all clients that desire the object. We present peer-to-peer (P2P) randomized overlays to obviate flash-crowd symptoms (PROOFS), a simple, lightweight, P2P approach that uses randomized overlay construction and randomized, scoped searches to locate and deliver objects efficiently under heavy demand to all users that desire them. We evaluate PROOFS' robustness in environments in which clients join and leave the P2P network, as well as in environments in which clients are not always fully cooperative. Through a mix of simulation and prototype experimentation in the Internet, we show that randomized approaches like PROOFS should effectively relieve flash crowd symptoms in dynamic, limited-participation environments.  相似文献   
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