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61.
Individuals with cytological atypia in sputum may be at increased risk for lung cancer. We conducted a longitudinal analysis of the association between lung cancer incidence and cytological atypia in sputum samples collected prospectively from an ongoing cohort of adults at high risk for lung cancer. Cohort members had a smoking history of > or = 30 pack-years and chronic obstructive pulmonary disease documented by pulmonary airflow testing. Sputum samples collected at baseline and periodically thereafter were examined by standard cytological methods. From the cohort of 2,006 people, there were 83 incident lung cancers over 4,469 person-years of observation. At baseline, the association between personal and behavioral characteristics, and sputum cytological atypia was assessed by multiple logistic regression. The association between sputum cytological atypia and incident lung cancer was then assessed by hazard ratios using proportional hazards regression analysis, adjusting for potential confounding factors. Cytological atypia graded as moderate or worse was associated with continuing cigarette smoking (adjusted odds ratio, 2.5; 95% confidence interval, 1.5-4.1), and with lower levels of intake of fruits and vegetables (P for trend = 0.04). Atypia was not associated with several other factors, including the degree of airflow obstruction, the use of vitamin supplements, nonsteroidal anti-inflammatory drugs, or metered-dose steroid inhalers. Incident lung cancer was increased among those with moderate or worse cytological atypia (adjusted hazards ratio, 2.8; 95% confidence interval, 1.4-5.5). This association was not confounded by other risk factors. We conclude that in this high-risk cohort, cytological atypia is associated with continuing smoking and low intake of fruits and vegetables, but that independent of these and other factors, the risk of incident lung cancer is increased among those with moderate or worse grades of cytological atypia in their sputum.  相似文献   
62.
63.
OBJECTIVE: To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available. PARTICIPANTS: A 17-member international physician panel with antiretroviral research and HIV patient care experience initially convened by the International AIDS Society-USA in December 1995. EVIDENCE: Available clinical and basic science data including phase 3 controlled trials; data on clinical, virologic, and immunologic end points; research conference reports; HIV pathogenesis data; and panel expert opinion. Recommendations were limited to therapies available (US Food and Drug Administration approved) in 1999. CONSENSUS PROCESS: The panel assesses new research reports and interim results and regularly meets to consider how the new data affect therapy recommendations. Recommendations are updated via full-panel consensus. Guidelines are presented as recommendations if the supporting evidence warrants routine use in the particular situation and as considerations if data are preliminary or incomplete but suggestive. CONCLUSIONS: The availability of new antiretroviral drugs has expanded treatment choices. The importance of adherence, emerging long-term complications of therapy, recognition and management of antiretroviral failure, and new monitoring tools are addressed. Optimal care requires individualized management and ongoing attention to relevant scientific and clinical information in the field.  相似文献   
64.
Martin S. Hirsch, MD; Françoise Brun-Vézinet, MD; Richard T. D'Aquila, MD; Scott M. Hammer, MD; Victoria A. Johnson, MD; Daniel R. Kuritzkes, MD; Clive Loveday, MD, PhD; John W. Mellors, MD; Bonaventura Clotet, MD, PhD; Brian Conway, MD; Lisa M. Demeter, MD; Stefano Vella, MD; Donna M. Jacobsen; Douglas D. Richman, MD

JAMA. 2000;283:2417-2426.

Objective  Assays for drug resistance testing in human immunodeficiency virus type 1 (HIV-1) infection are now available and clinical studies suggest that viral drug resistance is correlated with poor virologic response to new therapy. The International AIDS Society–USA sought to update prior recommendations to provide guidance for clinicians regarding indications for HIV-1 resistance testing.

Participants  An International AIDS Society–USA 13-member physician panel with expertise in basic science, clinical research, and patient care involving HIV resistance to antiretroviral drugs was reconvened to provide recommendations for the clinical use of drug resistance testing.

Evidence and Consensus Process  The full panel met regularly between January and October 1999. Resistance and resistance testing data appearing in the last decade through April 2000 and presentations at national and international research conferences were reviewed. Recommendations and considerations were developed by 100% group consensus, acknowledging that definitive data to support final recommendations are not yet available.

Conclusions  Emerging data indicate that despite limitations, resistance testing should be incorporated into patient management in some settings. Resistance testing is recommended to help guide the choice of new regimens after treatment failure and for guiding therapy for pregnant women. It should be considered in treatment-naive patients with established infection, but cannot be firmly recommended in this setting. Testing also should be considered prior to initiating therapy in patients with acute HIV infection, although therapy should not be delayed pending the results. Expert interpretation is recommended given the complexity of results and assay limitations.

  相似文献   

65.
During the past two decades many different treatment regimens of combination chemotherapy have been applied in extensive stage small-cell lung cancer (SCLC). This study was carried out to identify whether these modifications have resulted in an improved overall survival for extensive stage during the past two decades. In total, 1111 patients with extensive stage SCLC were included in six consecutive randomised trials in our setting from 1973 until 1992. Of these, 526 patients treated in the early period (1973–1981) were compared with 585 patients treated in the late period (1981–1992) with respect to pretreatment prognostic factors, staging, treatment and outcome. No change in the distribution of prognostic factors was detected and the frequency of patients with extensive stage was equal in the two periods, and no difference in overall response rates and survival was observed (P=0.49). Median survival in the two periods was 208 days and 215 days, respectively. No stage migration or treatment-related improved outcome was observed in extensive disease. We suggest restricting aggressive treatment to patients with favorable prognosis and long-term survival as a realistic aim.  相似文献   
66.
In Sweden, snuff (locally known as snus), was introduced since the year 1637. Presently, Sweden has the highest per capita consumption and sale figures of snuff in the world, and the habit is becoming increasingly popular. Snus is manufactured into a dry form used in the nasal cavity and a moist form used in the oral cavity. Snus manufactured for oral use is a moist ground tobacco of Dark Kentucky or Virginia species mixed with an aqueous solution of water and other blending ingredients. This form of snuff is found in two types: (1) loose and (2) portion-bag-packed. These are the most widely used. The loose moist form (1–2 g a quid) is the most popular type consumed by 73% of the males, followed by the portion-bag-packed form (0.5–1 g a quid), consumed by 13% of the males, while 14% of the males are mixed users. The majority of snus users place the quid in the vestibular area of the upper lip, and the prevalence among persons 15 years of age or older is 15.9% among males and 0.2% among females. The pH of snus has declined from a previous range of 8–9 to a range of 7.8–8.5, moisture content ranges 35–60% and nicotine content is in the order of 5–11 mg/g dry wt tobacco-specific N-nitrosamines (TSNAs) in micrograms (N′-nitrosonornicotine: NNN 5–9; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone: NNK 1–2; N′-nitrosoanatabine: NAT 2–5). In the Sudan, snuff, locally known as toombak, was introduced approximately 400 years ago. It is always processed into a loose moist form, and its use is widespread in the country. Tobacco used for manufacture of toombak is of the species Nicotiana rustica, and the fermented ground powder is mixed with an aqueous solution of sodium bicarbonate. The resultant product is moist, with a strong aroma, highly addictive and its use is widespread particularly among males. Its pH range is 8–11, moisture content ranges 6–60% and nicotine content is from 8 to 102 mg/g dry wt, and TSNAs contents in micrograms (NNN 420–1 550; NNK 620–7 870; NAT 20–290). Snus and toombak dippers develop a clinically and histologically characteristic lesion at the site of dipping. Probably due to control of the TSNAs in snus, this type of snuff is associated with a lower risk of cancer of the oral cavity (relative risk: RR 5–6-fold), whereas the risk for cancer of the oral cavity among toombak users was high (RR 7.3–73.0-fold). In conclusion, the two snuff products significantly differ in many aspects. Most notable differences are tobacco species, fermentation and ageing, nicotine and TSNAs content, pH, expression of the p53 tumour supressor gene, and keratin types 13, 14, and 19. It was, therefore, the object of the present study to highlight the oral health hazards of toombak, and to compare it with snus regarding the aforementioned differences.  相似文献   
67.
Mitochondrial free calcium levels measured by Rhod-2 fluorescence and ultrastructure were examined during cell death in nerve growth factor (NGF)-differentiated PC12 cells that were 1) exposed to C2-ceramide, 2) deprived of serum to induce endogenous ceramide production, or 3) treated with calcium ionophore A23187. Rhod-2 fluorescence in mitochondria and also in the nucleolus increased to a maximum within 3 hours after C2-ceramide treatment or serum withdrawal. In A23187-treated cells, Rhod-2 fluorescence remained at baseline levels. In all three models, enlargement of the endoplasmic reticulum was the first ultrastructural alteration, followed by mitochondrial shrinkage in ionophore-treated cells, but by mitochondrial swelling in the ceramide-dependent models, in which rupture of the outer mitochondrial membrane and unfolding of the inner membrane were frequently seen. Dihydro-C2-ceramide, which did not cause cell death, had no effect on cellular ultrastructure. NGF, which inhibits ceramide-dependent cell death, prevented the effects of serum deprivation on mitochondrial ultrastructure but not on endoplasmic reticulum morphology or Rhod-2 fluorescence. Nuclear shrinkage with loss of nuclear membrane integrity, characterized by nuclear pores, free or surrounded by electron-dense filaments, was a late event in ceramide-dependent cell death. Chromatin condensation and other morphological features associated with apoptosis were seen in only a few atypical cells. Ceramide-mediated cell death, therefore, did not involve classical apoptosis but was mediated by a reproducible series of events beginning in the endoplasmic reticulum, followed by the mitochondria, and then the nucleus. NGF-dependent cell death inhibition intervenes at the mitochondrial level, not by blocking the increase in Rhod-2 fluorescence but by preventing the ultrastructural changes that follow.  相似文献   
68.
IMPLICATIONS: Visual strokes can occur after prolonged hypotension or as a complication of preeclampsia-eclampsia. This case describes the diagnostic dilemma posed by a patient who developed transient blindness after a hypotensive episode during cesarean delivery for severe preeclampsia-eclampsia.  相似文献   
69.
PURPOSE: Azoospermia after electroejaculation in spinal cord injured men may be due to testicular failure or obstruction. These men can initiate pregnancy with assisted reproductive techniques, such as intracytoplasmic sperm injection, but only if sperm are present in the testis biopsy. We analyzed the histopathology of testis biopsies from spinal cord injured men and assessed whether patient factors were predictive of testis biopsy pathology. MATERIALS AND METHODS: A total of 50 paraplegic men undergoing testis biopsy were divided into 2 groups based on normal or abnormal testis histopathology. Patient age, post-injury years, level of lesion, hormonal status and semen analysis results were compared. RESULTS: Spermatogenesis was normal in 28 of the 50 patients. Hypospermatogenesis was exhibited in 15, maturation arrest at the spermatid stage in 6 and maturation arrest at the spermatocyte stage in 1 of the 22 abnormal cases. Nevertheless, mature sperm were identified in 43 of 50 biopsies (normal spermatogenesis and hypospermatogenesis). Men with normal spermatogenesis had better forward progression of sperm and a higher testosterone-to-luteinizing hormone ratio. Otherwise, there was no statistically significant correlation between study variables and testis biopsy results. No factors were predictive of testis biopsy histopathology. CONCLUSIONS: The documentation of mature sperm in 43 of 50 biopsies from spinal cord injured patients suggests that a high rate of sperm retrieval is possible using testicular sperm extraction if sperm cannot be retrieved from the ejaculate. With intracytoplasmic sperm injection techniques the majority of spinal cord injured men retain fertility potential, even if azoospermic following electroejaculation.  相似文献   
70.
RAD51 is an ATP-dependent recombinase, recruited by BRCA2 to mediate DNA double-strand breaks repair through homologous recombination and represents an attractive cancer drug target. Herein, we applied for the first-time protein-templated dynamic combinatorial chemistry on RAD51 as a hit identification strategy. Upon design of N-acylhydrazone-based dynamic combinatorial libraries, RAD51 showed a clear templating effect, amplifying 19 N-acylhydrazones. Screening against the RAD51–BRCA2 protein–protein interaction via ELISA assay afforded 10 inhibitors in the micromolar range. Further 19F NMR experiments revealed that 7 could bind RAD51 and be displaced by BRC4, suggesting an interaction in the same binding pocket of BRCA2. These results proved not only that ptDCC could be successfully applied on full-length oligomeric RAD51, but also that it could address the need of alternative strategies toward the identification of small-molecule PPI inhibitors.  相似文献   
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