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81.
Fanconi anemia (FA) is a recessive inherited disease characterized by defective DNA repair. FA cells are hypersensitive to DNA cross-linking agents that cause chromosomal instability and cell death. FA is manifested clinically by progressive pancytopenia, variable physical anomalies, and predisposition to malignancy. Four complementation groups have been identified, termed A, B, C, and D. The gene for the FA complementation group C, FACC, has been cloned. Expression of the FACC cDNA corrects the phenotypic defect of FA(C) cells, resulting in normalized cell growth in the presence of DNA cross-linking agents such as mitomycin C (MMC). Gene transfer of the FACC gene should provide a survival advantage to transduced hematopoietic cells, suggesting that FA might be an ideal candidate for gene therapy. We demonstrated efficient transduction, expression, and phenotypic correction in lymphoblastoid cell lines derived from FA (C) patients using a recombinant adeno-associated virus (rAAV) vector containing the FACC gene. Molecular characterization of the transduced FACC gene showed an intact unrearranged proviral genome with expression sufficient to normalize cell growth, cell cycle kinetics and chromosomal breakage in the presence of MMC. These observations were extended by testing rAAV transduction in hematopoietic progenitor cells. Peripheral blood CD34+ cells isolated from a FA (C) patient and transduced with rAAV/FACC virus yielded 5-10-fold more progenitor colonies than mock-infected cells, consistent with genetic "rescue" of corrected cells. This is the first demonstration of rAAV gene correction in primary human hematopoietic progenitor cells and has important implications for gene therapy of hematopoietic disorders, specifically FA.  相似文献   
82.
This study reports on a systematic statewide effort to determine the residential needs and preferences of two important groups: primary consumers of mental health services and family members of consumers. Two comparable surveys regarding the residential needs of consumers were conducted. In all, 314 consumers and 459 family members participated in the survey. A comparison of the preferences of family members and consumers suggests that family members more often prefer congregate living situations and more staff support than do consumers. Consumers more often express a desire to reside by themselves without staff and without other persons who are mentally ill. While the direct comparison of preferences from these two constituencies has limitations, these data do suggest significant variability in needs and preferences voiced by consumers and their family members; discrepancies that need to be addressed by mental health policymakers and planners.  相似文献   
83.
The gastropod mollusc Austrocochlea constricta was collected from four marine locations within the Newcastle region of New South Wales, Australia to assess the range and distribution of major bioaccumulated organic and heavy metal pollutants. The metals and organopollutants were extracted from the soft tissue and the shell of the mollusc for analysis using atomic absorption spectroscopy (AAS) and gas chromatography-mass spectroscopy (GC-MS). The organisms accumulated heavy metals from the sea water and concentrated them to levels substantially higher than those in the surrounding environment. A wide range of organopollutants was also detected in varying levels in Austrochochlea from each location. Abietic and dehydroabietic acids were detected only in the shell and not in the soft tissue suggesting that the shell may act as a toxic waste sink to facilitate the removal of potentially harmful compounds from the more metabolically active soft tissue. Aliphatic hydrocarbon contaminants were detected in Austrocochlea derived from the three sites associated with either heavy industry or recreational boating, but no hydrocarbons were detected in organisms from the control site. It was concluded that Austrocochlea may serve as a useful biomonitoring system of pollutants bioaccumulated from marine environments.  相似文献   
84.
85.
Damage to tooth structure is a major hazard in the use of infrared lasers for oral surgical procedures. While the effects of laser exposure on dental enamel and dentine are well characterized, there are no data on the effects of laser exposure on dental composite materials, which are widely used in tooth-colored restorations. This study examined surface changes in several dental composites exposed to CO2 laser radiation for 200 msec. Surface changes, such as ablation, combustion, and melting, occurred even at relatively low power densities (340 W/cm2), with greater effects occurring in composites than in "compomers" (glass iomomer-composite mixtures). These findings indicate that nonmetallic dental restorations are prone to damage from inadvertent laser exposure. Clinicians must be aware of this hazard and employ measures to protect both natural tooth structure and restorations when performing intraoral laser surgery.  相似文献   
86.
87.
The effects of low-intensity near-infra-red laser irradiation (820 nm; 1.5 and 9.0 J cm–2; pulsed at 12 Hz, 73 Hz and 5 kHz) upon peripheral neurophysiology and skin temperature were investigated using antidromic conduction studies in the human median nerve in vivo. Healthy human volunteers (n = 90) were recruited and allocated randomly to either a control group (n=10) or one of eight experimental groups (two radiant exposures, 1.5 J cm–2 and 9.0 J cm–2 at one of three pulse repetition rates, 12 Hz, 73 Hz or 5 kHz, in addition to a placebo group for each radiant exposure;n = 10 all groups). Analysis of variance (ANOVA) demonstrated a significant (p0.05) decrease in skin temperature following irradiation at the lowest radiant exposure (1.5 J cm–2) combined with pulse repetition rates of 73 Hz and 5 kHz, with the greatest effect at 73 Hz. These changes in skin temperature were coupled with increases in negative peak latency (NPL); ie changes in NPL were inversely related to changes in skin temperature. However, in contrast to the authors' previous findings using continuous wave (CW) laser irradiation, differences in NPL were not found to be significant. These findings, therefore, provide little evidence of the neuro-physiological effects of low-intensity infra-red irradiation at the dosage levels and pulse repetition rates used here.  相似文献   
88.
This study was designed to identify gender and age-related differences among complete denture referrals from general dental practice to a dental teaching hospital over a 4 year period. Referral rates were calculated according to male/female ratios in the edentulous population. Although more women than men were referred overall, the proportion of males to females referred was similar to that in the edentulous population. Significant gender-related differences in referral patterns were identified, suggesting that edentulous males with complete denture problems, and aged 69 or less, made proportionately less use of hospital services, and proportionately more when aged 70 or over.  相似文献   
89.
BACKGROUND: Insomnia is a very common symptom, particularly in the elderly. Thus, all hypnotic medications should be carefully evaluated in the elderly population. Zaleplon, a new nonbenzodiazepine hypnotic with a short elimination half-life (approximately 1 hour), was evaluated in the current study. METHOD: This multicenter, randomized, placebo-controlled outpatient study evaluated the efficacy and safety of zaleplon, 5 and 10 mg, in elderly patients with insomnia (as defined by DSM-IV); zolpidem, 5 mg, was the active comparator. Sleep was assessed in 549 elderly patients (>/= 65 years old) by using morning questionnaires completed after each of 7 baseline nights during which placebo was given, 14 nights of double-blind treatment, and 7 nights of placebo after discontinuation of active treatment. RESULTS: Zaleplon, 10 mg, and zolpidem, 5 mg, significantly reduced sleep latency during both weeks of the study. Zaleplon, 5 mg, reduced sleep latency only during week 2. Sleep duration was increased with zolpidem, 5 mg, during weeks 1 and 2 and with zaleplon, 10 mg, during week 1. No clinically significant rebound insomnia was observed after discontinuation of treatment with zaleplon, whereas evidence of rebound effects was seen with zolpidem. There was no significant difference between either zaleplon dose and placebo in the frequency of any central nervous system adverse events. CONCLUSION: Zaleplon is effective in reducing latency to sleep without evidence of undesired effects in elderly patients with insomnia.  相似文献   
90.
The initial pulmonary evaluation of the immunocompromised patient   总被引:1,自引:0,他引:1  
Practical approaches to the initial evaluation of solid organ transplant patients, BMT patients, and HIV-infected patients with pulmonary disease are summarized in Figures 2, 3, and 4. These algorithms are meant to be used as guidelines for the clinician. The clinical setting will ultimately determine the extent and speed of the evaluation. Patients who are recipients of solid organ transplants and have pulmonary symptoms may have focal or diffuse changes or may have normal chest radiographs. In all these groups, sputum is obtained by expectation. If a pathogen is found in any of the groups, it is treated. When no pathogen is found on sputum examination in patients with focal disease, empiric antibiotic therapy is given. If the patients do not improve on the empiric antibiotics, then bronchoscopy is performed. Some centers proceed directly to bronchoscopy before antibiotics are started in the hope of directing antibiotic therapy. Patients who have a normal CXR or diffuse infiltrates and no identified pathogen on examination of sputum undergo bronchoscopy, and the protocol is followed until a diagnosis is made (see Fig. 2). Patients who have received a BMT and who present with pulmonary symptoms are treated as shown in Figure 3. The CXR will reveal if the infiltrate is focal or diffuse. Those with focal infiltrates are treated with broad-spectrum antibiotics for 48 to 72 hours. If the symptoms and signs do not show some resolution, then bronchoscopy is usually performed. The effect of diffuse infiltrates in BMT patients depends to a large extent how far along in recovery from the transplant the patient is when they develop the infiltrates. During the first 30 days posttransplant, pulmonary edema commonly occurs, and the infiltrates may resolve with diuresis. If the patient is not clinically fluid overloaded or they do not respond to the diuretic therapy, then bronchoscopy with BAL is indicated. Finally, many HIV-infected patients may present with pulmonary symptoms. They may have a normal CXR or a diffuse or focal pattern (Fig. 4). All patients are subjected to sputum induction to identify a pathogen. If one is identified, it is treated. Should the patient not respond to treatment adequately or a pulmonary pathogen is not found, then bronchoscopy with BAL, protected specimen brush, or a transbronchial biopsy is attempted. The above schema is a general guideline to the initial evaluation of pulmonary disorders in the ICP. The respiratory abnormality is found in most of the cases if these algorithms are closely followed. If the patient does not improve or deteriorates further, additional diagnostic procedures such as video-assisted thorascopic lung biopsy or CT-directed transthoracic needle biopsy may be needed.  相似文献   
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