TGF beta-1 has been shown to upregulate matrix synthesis in articular chondrocytes. TGF beta-gene transfer to chondrocytes has the potential to increase the local production of this key component within regenerating cartilage after trauma and could support the repair process in articular cartilage lesions. Primary rabbit articular chondrocytes were cultured and retrovirally transfected with the experimental TGF beta-1 and the lacZ marker gene for control purposes. After radioactive labeling of new synthesized matrix proteins results were compared with normal primary chondrocytes. After TGF beta-1 gene transfer the endogenous growth factor concentration was doubled compared to normal chondrocytes and decreased in the lacZ control group. The proteoglycan synthesis in TGF beta-1 transfected chondrocytes showed a 96% increase compared to the basal production of normal chondrocytes. The LacZ transfected group revealed the opposite effect by a 44% decrease. The collagen synthesis of TGF beta-1 transfected chondrocytes was 304% compared to normal chondrocytes, predominantly type II collagen. The lacZ group collagen production was reduced by 35%. We conclude that TGF beta-1 gene transfer overcomes the decreasing effect observed by transfection with the LacZ marker gene and increases matrix synthesis in articular chondrocytes. Genetically altered chondrocytes might improve the repair of cartilage lesions by stimulating matrix synthesis and supporting the expression of the hyaline phenotype. 相似文献
BACKGROUND: Zinc is an essential trace element for human health and well-being; however, methods currently available for the assessment of zinc status in humans are unsatisfactory. OBJECTIVE: The objective was to critically evaluate the use of various indicators of zinc status in humans in a controlled metabolic ward study. DESIGN: Indicators of zinc status were measured in 25 healthy postmenopausal women aged 64.9 +/- 6.7 y. After a 10-d equilibration period, volunteers consumed a diet with either a low (1 mg/d; n = 12) or a high (3 mg/d; n = 13) copper content based on a total energy content of 8.4 MJ. They received the same amount of copper throughout the study. Both groups were fed the basal diet (3 mg Zn/d) with no zinc supplement for one 90-d period, and the diet supplemented with 50 mg Zn/d for another 90-d period. RESULTS: Zinc supplementation significantly increased (P < 0.0001) extracellular but not erythrocyte superoxide dismutase activity. This increase was more apparent when subjects were fed the low-copper diet. Zinc supplementation in combination with the low-copper diet significantly decreased (P < 0.01) amyloid precursor protein expression in platelets. Other indicators of zinc status that were significantly elevated after zinc supplementation were as follows: plasma zinc and free thyroxine concentrations and mononuclear 5'-nucleotidase activity. CONCLUSION: The measurement of serum extracellular superoxide dismutase activity may be useful as a marker for the functional assessment of zinc status in humans. 相似文献
The Authors for the Live Organ Donor Consensus Group
JAMA. 2000;284:2919-2926.
Objective To recommend practice guidelines for transplantphysicians, primary care providers, health care planners, andall those who are concerned about the well-being of the liveorgan donor.
Participants An executive group representing the NationalKidney Foundation, and the American Societies of Transplantation,Transplant Surgeons, and Nephrology formed a steering committeeof 12 members to evaluate current practices of living donortransplantation of the kidney, pancreas, liver, intestine, andlung. The steering committee subsequently assembled more than100 representatives of the transplant community (physicians,nurses, ethicists, psychologists, lawyers, scientists, socialworkers, transplant recipients, and living donors) at a nationalconference held June 1-2, 2000, in Kansas City, Mo.
Consensus Process Attendees participated in 7 assignedwork groups. Three were organ specific (lung, liver, and kidney)and 4 were focused on social and ethical concerns (informedconsent, donor source, psychosocial issues, and live organ donorregistry). Work groups' deliberations were structured by a seriesof questions developed by the steering committee. Each workgroup presented its deliberations to an open plenary sessionof all attendees. This information was stored and shaped intoa statement circulated electronically to all attendees for theircomments, and finally approved by the steering committee forpublication. The term consensus is not meant to convey universalagreement of the participants. The statement identifies issuesof controversy; however, the wording of the entire statementis a consensus by approval of all attendees.
Conclusion The person who gives consent to be a live organdonor should be competent, willing to donate, free from coercion,medically and psychosocially suitable, fully informed of therisks and benefits as a donor, and fully informed of the risks,benefits, and alternative treatment available to the recipient.The benefits to both donor and recipient must outweigh the risksassociated with the donation and transplantation of the livingdonor organ.
We previously created a transgenic mouse model of comorbid Tourette's syndrome and obsessive-compulsive disorder (TS+OCD), by expressing a neuropotentiating cholera toxin (CT) transgene in a subset of dopamine D1 receptor-expressing (D1+) neurons thought to induce cortical and amygdalar glutamate output. To test glutamate's role in the TS+OCD-like disorder of these transgenic mice (D1CT-7 line), the effects of glutamate receptor-binding drugs on their behavior were examined. MK-801, a non-competitive NMDA receptor antagonist that indirectly stimulates cortical-limbic glutamate output, aggravated a transgene-dependent abnormal behavior (repetitive climbing and leaping) in the D1CT-7 mice at doses insufficient to induce stereotypies, and more readily induced stereotypies and limbic seizure behaviors at high doses. NBQX, a seizure-inhibiting AMPA receptor antagonist, reduced only the MK-801-dependent stereotypic and limbic seizure behavior of D1CT-7 mice, but not their transgene-dependent behaviors. These data imply that TS+OCD-like behavior is mediated by cortical-limbic glutamate, but that AMPA glutamate receptors are not an essential part of this behavioral circuit. Our findings lead to the prediction that the symptoms of human Tourette's syndrome and obsessive-compulsive disorder are elicited by excessive forebrain glutamate output. 相似文献
Fast gradient-echo sequences that use an echo-train readout are becoming more widely used, particularly for imaging the heart. An important issue for these sequences involves determining the optimal duration for the echo-train readout. In normal volunteer scans and theoretically the echo-train readout duration was varied from 2.4 to 32.8 msec. Myocardial signal-to-noise ratio (SNR), myocardium-tag signal difference-to-noise ratio (SDNR), flow artifact-to-noise ratio (FNR), and geometric distortion were measured and/or calculated. Our results showed that to obtain high SNR, SDNR, and data acquisition efficiency while minimizing FNR and geometric distortion, the readout duration should be 10-15 msec at 1.5 T. 相似文献
PURPOSE: The aim of this study was to describe in detail the perinatal developmental profile of the pulmonary vasculature in congenital diaphragmatic hernia (CDH) and to examine the potential beneficial effects of extracorporeal membrane oxygenation (ECMO) on the vascular morphology. Additionally the authors aimed to identify the differences in pulmonary vascular morphology among CDH cases according to the primary cause of death: either extreme lung hypoplasia (LH) or persistent pulmonary hypertension (PPH). METHODS: The authors studied autopsy sections from 30 high-risk CDH cases with respect to the pulmonary arteries in relation to gestational age (GA) and ECMO treatment. They were grouped into CDH-I: 20 cases with GA greater than 34 weeks who were not subjected to ECMO and CDH-II: 10 cases with GA greater than 34 weeks, who were subjected to ECMO for an average time of 237 hours. Five age-matched neonates who died from placental insufficiency or birth asphyxia without evidence of lung hypoplasia served as controls (CON). Medial and adventitial thicknesses of pulmonary arteries were measured in lung sections stained with Elastic van Gieson by 2 investigators blinded for the clinical data. Immunohistological staining with anti-alpha-smooth muscle actin (alpha-SMA) was performed to confirm the precise location of the arterial media before morphometry. CDH cases were subgrouped and compared according to the primary cause of death. Unpaired Student t test was used for statistics, with significant P value < or =.05. RESULTS: In CDH newborns, a significant increase in medial, adventitial, and total wall thickness was found in pulmonary arteries with an external diameter of less than 200 microm as compared with age-matched controls (P<.004, .0001, and .0009, respectively). ECMO-treated CDH newborns showed a significantly thinner arterial adventitia than CDH patients who did not receive this treatment (P<.0001), approaching normal values. However, the medial thickness remained increased. Morphometrically, no significant differences in CDH cases between patients dying of PPH or severe LH could be determined. CONCLUSIONS: (1) In CDH, there is failure of the normal arterial remodeling processes occurring in the perinatal period. (2) Pulmonary vascular morphology in CDH does not differ between the groups with lung hypoplasia or persistent pulmonary hypertension as primary cause of death. (3) Adventitial thinning of these arteries might be one of the mechanisms by which ECMO alters PPH in CDH cases. 相似文献
Following the recent discovery that GABA(B) receptors expressed in cell lines are only functional when both GABA(B1) and GABA(B2) are expressed, the present study reports on the development of polyclonal antisera specific for carboxyl-terminal portions of the two related GABA(B) receptor components respectively. Western blotting indicated the specificity of affinity-purified antibodies for native or recombinant expressed GABA(BR1) and GABA(BR2), with no cross-reactivity, both antisera detecting the heterodimer in rat cerebellar membranes. Immunohistochemistry revealed a distinct distribution of both receptor proteins in rat cerebellum. GABA(B1) immunoreactivity was primarily located in the granule cell layer and Purkinje cells, with discrete immuno-positive cell bodies being present in the molecular layer. GABA(B2) staining revealed intense immunoreactivity in the molecular layer, with weaker staining in the granule cell layer. Purkinje cell bodies were less intensely immuno-positive for GABA(B2). Co-localisation of both receptor proteins was observed using double immunofluorescence techniques, consistent with the notion that both proteins are required for the formation of functional GABA(B) receptors in vivo. Immunofluorescence also indicated that GABA(B) receptors did not co-localise with glial fibrillary acid protein, confirming a neuronal localisation for GABA(B) receptors. Electron microscopic analysis of the molecular layer revealed that the distribution of immunolabelling for both GABA(B1) and GABA(B2) was mainly located on the membrane of Purkinje cell dendrites and spines and in parallel fibre terminals. 相似文献
This paper describes a PC-based system for simultaneous monitoring of locomotor and sound activities on small rodents. The displacement and location signals of the animal were first determined across consecutive video-frames, followed by marked data reduction to cater for long-term studies. At the same time, sounds generated by the animal were detected and the sound level was recorded as root-mean-square values at 1 s intervals. Preliminary data showed that such a multi-parametric monitor system could provide comprehensive information on the animal's activity. 相似文献