The effect of non-steroidal anti-inflammatory drugs on osteosarcoma cells.

OBJECTIVE: Osteosarcoma (OS), an aggressive malignancy, is the most common primary bone tumor in children. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to reduce pain and inflammation. NSAIDs have shown to be toxic to certain malignancies such as colorectal, breast, and pancreatic cancers, but are not well-studied in OS. The purpose of this study is to assess whether ketorolac induces apoptosis in OS cells, compare this to indomethacin, which has been shown to inhibit OS proliferation, and explore the underlying mechanism. MATERIALS AND METHODS: A rat OS cell line (UMR-108) was exposed to various concentrations of ketorolac and indomethacin. Cell viability, cytotoxicity, apoptosis induction, DNA fragmentation and the expression of apoptosis-related markers were examined by MTT assay, colony formation assay, flow cytometry, agarose gel electrophoresis, and Western blot respectively. RESULTS: The results indicated that ketorolac and indomethacin could induce apoptosis of rat OS cells in a dose- and time-dependent manner. Apoptosis was confirmed by cell morphology and annexin positivity. The molecular data showed that NSAIDs affected expression of Bcl-2, survivin, and Poly (ADP-ribose) polymerase-1 (PARP). CONCLUSIONS: These findings demonstrated that NSAIDs induced apoptosis in rat OS cells in vitro. Further research focusing on the potential cytotoxicity of NSAIDs in vivo is needed.

Liver injury is associated with mortality in sickle cell disease.

BACKGROUND: Increased life expectancy in sickle cell disease (SCD) has resulted in greater recognition of the consequences of repeated intravascular vaso-occlusion and chronic haemolysis to multiple organ systems. AIM: To report the long-term consequences of liver dysfunction in SCD. METHODS: A cohort of SCD patients was prospectively evaluated at the National Institutes of Health (NIH) Clinical Center. The association of mortality with liver enzymes, parameters of liver synthetic function and iron overload was evaluated using Cox regression. RESULTS: Exactly, 247 SCD patients were followed up for 30 months of whom 22 (9%) died. After controlling for predictors, increased direct bilirubin (DB), ferritin, alkaline phosphatase and decreased albumin were independently associated with mortality. In a multivariable model, only high DB and ferritin remained significant. Ferritin correlated with hepatic iron content and total blood transfusions but not haemolysis markers. Forty patients underwent liver biopsies and 11 (28%) had fibrosis. Twelve of 26 patients (48%) had portal hypertension by hepatic venous pressure gradient (HVPG) measurements. All patients with advanced liver fibrosis had iron overload; however, most patients (69%) with iron overload were without significant hepatic fibrosis. Ferritin did not correlate with left ventricular dysfunction by echocardiography. DB correlated with bile acid levels suggesting liver pathology. Platelet count and soluble CD14 correlated with HVPG indicating portal hypertension. CONCLUSIONS: Ferritin and direct bilirubin are independently associated with mortality in sickle cell disease. Ferritin likely relates to transfusional iron overload, while direct bilirubin suggests impairment of hepatic function, possibly impairing patients' ability to tolerate systemic insults.

Genome-wide analysis of transcriptomic divergence between laboratory colony and field Anopheles gambiae mosquitoes of the M and S molecular forms.

Our knowledge of Anopheles gambiae molecular biology has mainly been based on studies using inbred laboratory strains. Differences in the environmental exposure of these and natural field mosquitoes have inevitably led to physiological divergences. We have used global transcript abundance analyses to probe into this divergence, and identified transcript abundance patterns of genes that provide insight on specific adaptations of caged and field mosquitoes. We also compared the gene transcript abundance profiles of field mosquitoes belonging to the two morphologically indistinguishable but reproductively isolated sympatric molecular forms, M and S, from two different locations in the Yaoundé area of Cameroon. This analysis suggested that environmental exposure has a greater influence on the transcriptome than does the mosquito's molecular form-specific genetic background.

A simple fluorescent biosensor for theophylline based on its RNA aptamer.

Theophylline is a potent bronchodilator with a narrow therapeutic index. A simple fluorescent biosensor that detects clinically relevant theophylline concentrations has been developed using the well-characterized theophylline binding RNA aptamer. Hybridization of the RNA aptamer to a fluorescently labeled DNA strand (FL-DNA) yields a fluorescent RNA:DNA hybrid that is sensitive to theophylline. The biosensor retains the remarkable selectivity of the RNA aptamer for theophylline over caffeine and is sensitive to 0-2 muM theophylline, well below the clinically relevant concentration (5-20 mg/L or approximately 10-50 muM). Adding a dabcyl quenching dye to the 3'-terminus of the fluorescently labeled DNA strand yielded a dual-labeled DNA strand (FL-DNA-Q) and increased the dynamic range of this simple biosensor from 1.5-fold to 4-fold.

Simulated impairment of contrast sensitivity: performance and gaze behavior during locomotion through a built environment.

PURPOSE: An experimental study investigated the effects of simulated impairment of contrast sensitivity (CS) on performance and eye gaze patterns during locomotion through a library. METHOD: Normally sighted participants with simulated CS impairment (diffusive blur) walked two routes, one entailing limited change in direction (simple) and the other entailing several changes in direction (complex), while eye movements relative to the scene were recorded. Performance variables included walking speed in completing the route, pauses during travel, and collisions with objects on the route. For eye movements, dwell time and saccades were determined for each of three object classes: (1) objects on the route below eye level; (2) objects on the route extending above eye level; and (3) elsewhere-objects not on the route. RESULTS: Walking speed was significantly affected by CS level and by route; pauses and collisions were rare. Dwell times and saccades suggested limited attention directed to low-level objects, except for CS impairment on the complex route. In the complex route, saccades and dwell times in the object class "elsewhere" were also reduced. CONCLUSIONS: The results for the simple route suggest ballistic strategies: the participant appraises the scene and follows a more or less predetermined path. For the complex route, CS impairment appears to adversely affect information processing and locomotion. The results have implications for the design of built environments, especially with regard to the safety of visually impaired occupants during emergency scenarios.

Management of metabolic syndrome: aspirin.

Cardiovascular disease (CVD), which includes myocardial infarction(MI), stroke, and peripheral vascular disease, remains the leading cause of death in the United States and in most developed countries. In the United States today, 25% of patients have metabolic syndrome-including those who have had a prior occlusive vascular disease event, those who are having an acute MI or ischemic stroke, and finally, the largest segment of the population,namely those who have not yet experienced a clinical CVD, but whose risks are substantial (10-year risk 10%). This article reviews the totality of evidence for aspirin in the treatment and prevention of CVD and emphasizes its importance as adjunctive therapy for patients with metabolic syndrome.

A case-control study of endogenous hormones and cervical cancer.

Both parity and oral contraceptive use are associated with elevated circulating levels of sex hormones, at least transiently, and with increased risk of cervical cancer in human papillomavirus (HPV)-infected women. We directly evaluated whether elevations in the physiologic levels of these hormones predispose to the development of cervical neoplasia. We identified 67 premenopausal and 43 postmenopausal women with cervical intraepithelial neoplasia 2, 3, or cervical cancer (>/=CIN2) diagnosed during enrollment of a population-based cohort of 10 077 women. Four controls, two chosen randomly and two chosen from women testing positive for cancer-associated HPV, were matched to each case on menopausal status, age, days since last menses (pre), or years since menopause (post). Sex hormone-binding globulin, oestradiol, oestrone, oestrone-sulphate, dehydroepiandrosterone sulphate, and progesterone were measured in enrollment plasma. There was no consistent association between the sex hormones and risk of >/=CIN2. Excluding cases with invasive disease had a minimal impact on results. Though this case-control study was based on a well-defined population, it was limited by reliance on a single measure of hormone levels taken at the time of diagnosis. Nonetheless, our results do not support the hypothesis that plasma levels of sex hormones have an important bearing on the risk of cervical neoplasia in HPV-infected women.

Seroprevalence of human papillomavirus-16, -18, -31, and -45 in a population-based cohort of 10000 women in Costa Rica.

Human papillomavirus (HPV) seroprevalence and determinants of seropositivity were assessed in a 10049-woman population-based cohort in Guanacaste, Costa Rica. Serologic responses based on VLP-based ELISA were obtained from the plasma collected at study enrollment in 1993/1994 for HPV-16 (n=9949), HPV-18 (n=9928), HPV-31 (n=9932), and HPV-45 (n=3019). Seropositivity was defined as five standard deviations above the mean optical density obtained for studied virgins (n=573). HPV-16, -18, -31, and -45 seroprevalence was 15, 15, 16, and 11%, respectively. Of women DNA-positive for HPV-16, -18, -31, or -45, seropositivity was 45, 34, 51, and 28%, respectively. Peak HPV seroprevalence occurred a decade after DNA prevalence; lifetime number of sexual partners was the key determinant of seropositivity independent of DNA status and age. DNA- and sero-positive women showed the highest risk for concurrent CIN3/cancer, followed by DNA-positive, sero-negative women.

Geographic epidemiology of gonorrhoea and chlamydia on a large military installation: application of a GIS system.

OBJECTIVES: The geographic epidemiology of infectious diseases can help in identifying point source outbreaks, elucidating dispersion patterns, and giving direction to control strategies. We sought to establish a geographic information system (GIS) infectious disease surveillance system at a large US military post (Fort Bragg, North Carolina) using STDs as the initial outcome for the model. METHODS: Addresses of incident cases were plotted onto digitised base maps of Fort Bragg (for on-post addresses) and surrounding Cumberland County, NC (for off-post addresses) using MAPINFO Version 5. We defined 26 geographic sectors on the installation. Active duty soldiers attending the post preventive medicine clinic were enrolled between July 1998 and June 1999. RESULTS: Gonorrhoea (GC) was diagnosed in 210/2854 (7.4%) and chlamydia (CT) in 445/2860 (15.6%). African-American male soldiers were at higher risk for GC (OR = 4.6 (95% CL 3.0 to 7.2)) and chlamydia (OR = 2.0 (1.4 to 2.7)). For women, there were no ethnic differences in gonorrhoea prevalence, but chlamydia was higher in African-Americans (OR = 2.0 (1.4-2.7)). Rank and housing type were associated with gonorrhoea and chlamydia in men, but were not significant factors in women. For gonorrhoea, two geographic sectors had prevalences between 14.0%-16.5%, three between 10.3%-13.9%, three between 7.1%-10.2%, and five between 3.0%-7.1%. The geographic distribution demonstrated a core-like pattern where the highest sectors were contiguous and were sectors containing barracks housing lower enlisted grade personnel. In contrast, chlamydia prevalence was narrowly distributed. CONCLUSION: GIS based disease surveillance was easily and rapidly implemented in this setting and should be useful in developing preventive interventions.

Changes and continuities in the determinants of older adults' voter turnout 1952-1996.

PURPOSE: The goal of this project was to examine the factors related to the high level of voter turnout among older adults and how these factors have changed across the past 50 years. The study builds on previous research efforts by combining individual level analyses from three nationally representative surveys. DESIGN AND METHODS: We examined voter turnout among older citizens using the American National Election Studies (ANES) 1952-1996, the Current Population Studies (CPS) 1972-1996, and the General Social Surveys (GSS) 1972-1996. Logit regression identified significant factors that contribute to or detract from voting in presidential elections. RESULTS: Included in the extensive results, we found that being married, attending church, and contact by political operatives (since the 1980 election) contributed positively to older voters' turnout, whereas living in the South was a negative predictor. IMPLICATIONS: Triangulating data sources, we are able to utilize the strengths of each study-providing an overview of the determinants of voter turnout and understanding of the changes related to older Americans' turnout in presidential elections.

Application of a geographic information system to the tracking and control of an outbreak of shigellosis.

A personal computer-based commercial geographic information system (GIS) was applied to an outbreak of Shigella sonnei infection at Fort Bragg, North Carolina. We used a database consisting of demographic, temporal, and home-address information for all recognized cases of S. sonnei that occurred among health care beneficiaries from 23 May 1997 through 14 August 1997. We imported this database into the GIS, which contained a digitized basemap of the local community. Through simultaneous examination of temporal and spatial distribution of the 59 identified cases of S. sonnei, a focus of infection in a single housing area was identified. Targeted education among residents of the neighborhood in which there was intense transmission was associated with prompt extinction of the epidemic. A GIS offers an efficient and practical way to directly visualize the dynamics of transmission of infectious diseases in the setting of a community outbreak.

Molecular interactions and metal binding in the theophylline-binding core of an RNA aptamer.

An RNA aptamer containing a 15-nt binding site shows high affinity and specificity for the bronchodilator theophylline. A variety of base modifications or 2' deoxyribose substitutions in binding-site residues were tested for theophyllinebinding affinity and the results were compared with the previously determined three-dimensional structure of the RNA-theophylline complex. The RNA-theophylline complex contains a U6-A28-U23 base triple, and disruption of this A28-U23 Hoogsteen-pair by a 7-deaza, 2'-deoxy A28 mutant reduces theophylline binding >45-fold at 25 degrees C. U24 is part of a U-turn in the core of the RNA, and disruption of this U-turn motif by a 2'-deoxy substitution of U24 also reduces theophylline binding by >90-fold. Several mutations outside the "conserved core" of the RNA aptamer showed reduced binding affinity, and these effects could be rationalized by comparison with the three-dimensional structure of the complex. Divalent ions are absolutely required for high-affinity theophylline binding. High-affinity binding was observed with 5 mM Mg2+, Mn2+, or Co2+ ions, whereas little or no significant binding was observed for other divalent or lanthanide ions. A metal-binding site in the core of the complex was revealed by paramagnetic Mn2+-induced broadening of specific RNA resonances in the NMR spectra. When caffeine is added to the aptamer in tenfold excess, the NMR spectra show no evidence for binding in the conserved core and instead the drug stacks on the terminal helix. The lack of interaction between caffeine and the theophylline-binding site emphasizes the extreme molecular discrimination of this RNA aptamer.

Using remotely sensed data to identify areas at risk for hantavirus pulmonary syndrome.

The 1993 U.S. hantavirus pulmonary syndrome (HPS) outbreak was attributed to environmental conditions and increased rodent populations caused by unusual weather in 1991- 92. In a case-control study to test this hypothesis, we estimated precipitation at 28 HPS and 170 control sites during the springs of 1992 and 1993 and compared it with precipitation during the previous 6 years by using rainfall patterns at 196 weather stations. We also used elevation data and Landsat Thematic Mapper satellite imagery collected the year before the outbreak to estimate HPS risk by logistic regression analysis. Rainfall at case sites was not higher during 1992-93 than in previous years. However, elevation, as well as satellite data, showed association between environmental conditions and HPS risk the following year. Repeated analysis using satellite imagery from 1995 showed substantial decrease in medium- to high-risk areas. Only one case of HPS was identified in 1996.

Effects of dose and interdose interval on conditioned heart rate tolerance to smoking.

The effects of an environmental cue and smoking administration on heart rate (HR) responses to smoking were investigated in 2 studies. The 1st study was performed without smoking, to rule out the possibility that the cue manipulations alone could produce HR habituation. Thirty-six male nonsmokers were exposed to 6 trials of a changing or repeating cue (segments of a story on audiotape), followed by a paced-breathing period. HR habituation was not found. In the 2nd study, 40 male smokers smoked 4 puffs every 10 min (small-dose/long-interdose interval [IDI]) or 6 puffs every 5 min (large-dose/short-IDI) in 6 trials. The same repeating or changing cue preceded smoking. Only the repeating-cue, small-dose/long-IDI group developed HR tolerance. Modifying the cue on Trial 6 did not reverse tolerance. The results indicated that (a) tolerance to smoking appears to be subject to conditioning, (b) this effect depends on the dose and IDI, and (c) the observed tolerance is not likely to be a result of the effects of the cue alone. Nonassociative tolerance to smoking a high-dose/short-IDI did not occur in this study.

The additional risk of endometrial cancer associated with unopposed estrogen use in women with other risk factors.

We analyzed data from a population-based case-control study of endometrial cancer. Our goal was to identify a subgroup of women in whom the additional cancer risk associated with unopposed estrogen use was sufficiently small so as to not be a deterrent to taking a hormone preparation of this type. Researchers interviewed women with endometrial cancer (N = 553) and controls (N = 752) regarding hormone use. The additional risk of endometrial cancer associated with unopposed estrogen use did not vary substantially in the presence or absence of hypertension, parity, oral contraceptive use, or smoking. The results suggest that, although heavier women may experience a greater risk of endometrial cancer associated with unopposed estrogen use (8.2 per 1,000 per year) than lighter women (4.2 per 1,000 per year), long-term users in the latter group nonetheless face a substantial absolute increase in risk. We conclude that subdividing women on the basis of the presence or absence of other known risk factors for endometrial cancer fails to delineate a subgroup that is exempt from the increased risk of this cancer associated with use of unopposed estrogens. 83.6% of estrogen users reported taking conjugated estrogens.

High-performance liquid chromatography purification of homogenous-length RNA produced by trans cleavage with a hammerhead ribozyme.

An improved method is presented for the preparation of milligram quantities of homogenous-length RNAs suitable for nuclear magnetic resonance or X-ray crystallographic structural studies. Heterogeneous-length RNA transcripts are processed with a hammerhead ribozyme to yield homogenous-length products that are then readily purified by anion exchange high-performance liquid chromatography. This procedure eliminates the need for denaturing polyacrylamide gel electrophoresis, which is the most laborious step in the standard procedure for large-scale production of RNA by in vitro transcription. The hammerhead processing of the heterogeneous-length RNA transcripts also substantially improves the overall yield and purity of the desired RNA product.

Four-month, four-drug preventive therapy for inactive pulmonary tuberculosis.

Standard preventive therapy for inactive pulmonary tuberculosis (TB) is 12 mo of isoniazid. Shorter multiple-drug preventive regimens have been proposed. From December 1993 through January 1996 we evaluated a 4-mo, four-drug regimen of preventive therapy for patients with inactive TB, mostly newly arriving immigrants from countries with high rates of TB and of isoniazid resistance. Fifty-three evaluable patients received a 4-mo regimen of isoniazid, rifampin, ethambutol, and pyrazinamide. We compared their completion rate, side effects, and cost of treatment with those of 108 age-matched patients who had received 12 mo of isoniazid at an earlier time. Sixty-eight percent of patients on the 4-mo regimen completed treatment; 69% of those on the 12-mo regimen completed treatment (p = 0.9393). Side effects were more frequent for the 4-mo regimen (30.2%) compared with 12 mo of isoniazid (11.1%) (p = 0. 0027). The cost of providing an uncomplicated, self-supervised regimen was estimated to be almost four times greater for the four-drug regimen compared with isoniazid. These results show that, in terms of compliance, a four-drug, 4-mo regimen had no advantage over standard preventive therapy for persons with inactive pulmonary TB. On the other hand, the shorter, more intensive regimen was associated with more frequent adverse effects and was more costly.

Mediastinal parathyroid cysts revisited.

BACKGROUND: A case of a functioning mediastinal cyst is presented. METHODS: A comprehensive review of the literature found 93 patients in whom a parathyroid cyst or cysts extended into, or was completely contained within, the mediastinum. Including our patient, there were 46 men and 45 women, and the gender was not recorded in three. RESULTS: The cysts were located in the anterosuperior region in 56 patients, in the middle region of the mediastinum in 26, and in the anterior, prevascular region in 12. Thirty-nine patients had functioning cysts associated with hyperparathyroidism of varying severity; seven patients presented with a hypercalcemic crisis. Local symptomatology consisted of a neck mass, respiratory distress, and occasional dysphagia or chest pain. Recurrent laryngeal nerve paresis was present in nine patients, and innominate vein compression or thrombosis was present in two. The cysts in all but four patients were treated by open surgical excision; two were treated by thoracoscopy, and two patients only had fine-needle aspiration of the cyst. The cyst was excised via a cervical approach in 67 patients and by a thoracotomy or median sternotomy or a variation thereof in 23. There was no operative mortality and morbidity was minimal. CONCLUSION: Surgical resection was successful in all and remains the treatment of choice for mediastinal parathyroid cysts.