Vascular risk factors and cognitive impairment in a stroke-free cohort

OBJECTIVE

To examine vascular risk factors, as measured by the Framingham Stroke Risk Profile (FSRP), to predict incident cognitive impairment in a large, national sample of black and white adults age 45 years and older.

METHODS

Participants included subjects without stroke at baseline from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study with at least 2 cognitive function assessments during the follow-up (n = 23,752). Incident cognitive impairment was defined as decline from a baseline score of 5 or 6 (of possible 6 points) to the most recent follow-up score of 4 or less on the Six-item Screener (SIS). Subjects with suspected stroke during follow-up were censored.

RESULTS

During a mean follow-up of 4.1 years, 1,907 participants met criteria for incident cognitive impairment. Baseline FSRP score was associated with incident cognitive impairment. An adjusted model revealed that male sex (odds ratio [OR] = 1.59, 95% confidence interval [CI] 1.43-1.77), black race (OR = 2.09, 95% CI 1.88-2.35), less education (less than high school graduate vs college graduate, OR = 2.21, 95% CI 1.88-2.60), older age (10-year increments, OR = 2.11, per 10-year increase in age, 95% CI 2.05-2.18), and presence of left ventricular hypertrophy (LVH, OR = 1.29, 95% CI 1.06-1.58) were related to development of cognitive impairment. When LVH was excluded from the model, elevated systolic blood pressure was related to incident cognitive impairment.

CONCLUSIONS

Total FSRP score, elevated blood pressure, and LVH predict development of clinically significant cognitive dysfunction. Prevention and treatment of high blood pressure may be effective in preserving cognitive health.

Nutritional effects of culture media on mycoplasma cell size and removal by filtration

Careful media filtration prior to use is an important part of a mycoplasma contamination prevention program. This study was conducted to increase our knowledge of factors that influence efficient filtration of mycoplasma. The cell size of Acholeplasma laidlawii was measured after culture in various nutritional conditions using scanning electron microscopy. The maximum cell size changed, but the minimum cell size remained virtually unchanged and all tested nutritional conditions resulted in a population of cells smaller than 0.2 microm. Culture in Tryptic Soy Broth (TSB) resulted in an apparent increase in the percentage of very small cells which was not reflected in increased penetration of non-retentive 0.2 microm rated filters. A. laidlawii cultured in selected media formulations was used to challenge 0.2 microm rated filters using mycoplasma broth base as the carrier fluid. We used 0.2 microm rated filters as an analytical tool because A. laidlawii is known to penetrate 0.2 microm filters and the degrees of penetration can be compared. Culture of A. laidlawii in TSB resulted in cells that did not penetrate 0.2 microm rated filters to the same degree as cells cultured in other media such as mycoplasma broth or in TSB supplemented with 10% horse serum.

Association of higher diastolic blood pressure levels with cognitive impairment

BACKGROUND

We evaluated the cross-sectional relationship of blood pressure (BP) components with cognitive impairment after adjusting for potential confounders.

METHODS

Reasons for Geographic and Racial Differences in Stroke (REGARDS) is a national, longitudinal population cohort evaluating stroke risk in 30,228 black and white men and women >or=45 years old. During the in-home visit, BP measurements were taken as the average of 2 measurements using a standard aneroid sphygmomanometer. Excluding participants with prior stroke or TIA, the present analysis included 19,836 participants (enrolled from December 2003 to March 2007) with complete baseline physical and cognitive evaluations. Incremental logistic models examined baseline relationships between BP components (systolic blood pressure [SBP], diastolic blood pressure [DBP], and pulse pressure [PP]) and impaired cognitive status (score of <or=4 on 6-Item Screener) after adjusting for demographic and environmental characteristics, cardiovascular risk factors, depressive symptoms, and current use of any antihypertensive medication.

RESULTS

Higher DBP levels were associated with impaired cognitive status after adjusting for demographic and environmental characteristics, risk factors, depressive symptoms, and antihypertensive medications. An increment of 10 mm Hg in DBP was associated with a 7% (95% confidence interval [CI] 1%-14%, p = 0.0275) higher odds of cognitive impairment. No independent association was identified between impaired cognitive status and SBP (odds ratio [OR] 1.02, 95% CI 0.99-1.06) or PP (OR 0.99, 95% CI 0.95-1.04). There was no evidence of nonlinear relationships between any of the BP components and impaired cognitive status. There was no interaction between age and the relationship of impaired cognitive status with SBP (p = 0.827), DBP (p = 0.133), or PP (p = 0.827) levels.

CONCLUSIONS

Higher diastolic blood pressure was cross-sectionally and independently associated with impaired cognitive status in this large, geographically dispersed, race- and sex-balanced sample of stroke-free individuals.

Cigarette smoking, disease severity and autoantibody expression in African Americans with recent-onset rheumatoid arthritis

OBJECTIVE

To examine the association of smoking with clinical and serological features in African Americans with recent-onset rheumatoid arthritis (RA) and to explore whether this association is dependent on the presence of the HLA-DRB1 shared epitope (SE).

METHODS

In African Americans with recent-onset RA (n = 300), we examined the association of cigarette smoking (current versus past versus never and pack-years of exposure) with anti-cyclic citrullinated peptide antibody, rheumatoid factor (RF) (IgM and IgA), rheumatoid nodules and baseline radiographic erosions using logistic and cumulative logistic regression (adjusting for SE status). We also examined for evidence of interaction between smoking status and SE for all outcomes.

RESULTS

Although there was no association with RF-IgA seropositivity, current smokers were approximately twice as likely as never smokers to have higher IgA-RF concentrations (based on tertiles; OR = 1.74; 95% CI 1.05 to 2.88) and nodules (OR = 2.43; 95% CI 1.13 to 5.22). These associations were most pronounced in those with more than 20 pack-years of exposure. There was no association of smoking status or cumulative tobacco exposure with anti-cyclic citrullinated peptide antibody, IgM-RF or radiographic erosions. There was also no evidence of a biological or statistical SE-smoking interaction for any of the outcomes examined.

CONCLUSIONS

This is the first study to systematically examine the association of cigarette smoking with RA-related features in African Americans. Cigarette smoking is associated with both subcutaneous nodules and higher serum concentrations of IgA-RF in African Americans with RA, associations that may have important implications for long-term outcomes in this population.

Activation and transposition of endogenous retroviral elements in hypomethylation induced tumors in mice

Genomewide DNA hypomethylation is a consistent finding in human tumors, but the importance of this change for human tumorigenesis remains an open question. We have previously reported that mice carrying a hypomorphic allele for the maintenance DNA methyltransferase (Dnmt1(chip/-)) are hypomethylated and develop thymic lymphomas, demonstrating that genomewide DNA hypomethylation can induce tumors. Hypomethylated cells exhibit inherent chromosomal instability, which is revealed in the lymphomas as a consistent trisomy of chromosome 15. We now report another aspect of the molecular basis for tumor development upon DNA hypomethylation. Seven out of 16 hypomethylation-induced lymphomas were found to contain an intracisternal A particle (IAP) somatic insertion in the middle of the Notch1 genomic locus, leading to generation of an oncogenic form of Notch1 in the tumors. This finding suggests that the molecular basis for hypomethylation-induced tumors in this model involves chromosomal instability events accompanied by activation of endogenous retroviral elements. Our findings validate the proposed role of DNA methylation in suppression of transposable elements in mammalian cells and demonstrate the importance of DNA methylation for normal cell function as well as the potential consequences of spontaneously occurring or chemically induced DNA hypomethylation.

Investigating gender specific metabolic differences in non-small cell lung cancer by F-18 FDG PET

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Background: Lung cancer is the leading cause of cancer death in women, killing more women than breast, ovarian, and uterine cancers combined. Recent evidence suggests differences in lung cancer between the sexes. Women have better rates of survival, different histology, genetic, and molecular factors as compared to men. Metabolic characteristics of lung cancer have prognostic value. The use of F-18 FDG Positron Emission Tomography (PET) has been demonstrated in multiple studies to better determine outcome, improve diagnostic and staging techniques. Methods: 251 (M:F=101:150) patients with newly diagnosed biopsy proven NSCLC and evaluated by F-18 FDG PET(CT), without other malignancies, prior radiation or chemotherapy, were analyzed retrospectively from our institution. PET scans were obtained 1 hour after injection of 370 MBq F-18 FDG using a dedicated whole body PET-CT or PET scanner. The PET images were reconstructed with attenuation correction by either radioisotope or CT transmission scan. The SUV, defined as tumor activity divided by dose injected per lean body mass, from the PET cameras had been cross validated to produce the same value in a given phantom and patient. The maximum SUV was measured by searching the maximum value within a volume of known primary cancer. Results: The two groups were matched for age. Females had significantly less squamous cell carcinomas (18% vs. 29%, p=0.025) and more adenocarcinomas (41% vs. 30%, p=0.041) than males. Although there were no significant differences stage by stage between males and females, there was gradual transition or increment of SUV by stage in all female NSCLC with the SUV of stage I NSCLC being lower than that of cancers in stages II, III or IV (p=0.00022, 0.0088, and 0.0026 respectively). However, there were no such distinctions among male patients. There were no differences in SUV among various histological types of NSCLC between the sexes. Conclusions: The study suggests there are gender differences in the metabolic properties of NSCLC with distinctively more metabolically aggressive NSCLCs upon advancing stage in women but not in men. This gender specific metabolic difference is another discriminator besides other known gender factors and is potentially useful in the management of early stage NSCLC in women.

No significant financial relationships to disclose.

The effectiveness of low dose droperidol in controlling nausea and vomiting during epidural anesthesia for cesarean section

The antiemetic efficacy of 0.5 mg of droperidol was evaluated in 128 term parturients undergoing elective and non-urgent cesarean section with epidural anesthesia. Following delivery, parturients received intravenously either 0.5 mg of droperidol or normal saline in a double-blinded fashion. Droperidol decreased nausea after delivery from 41 to 13% (P=0.001). There was no significant decrease in the incidence of vomiting. Analysis of the data using logistic regression analysis showed that increasing age (P = 0.002), hypotension after delivery (P = 0.040), and vomiting prior to delivery (P = 0.017) were associated with increased nausea after delivery. No extrapyramidal symptoms or significant changes in pulse rate or blood pressure were associated with droperidol administration. We conclude that 0.5 mg of intravenous droperidol decreases nausea in term parturients undergoing non-urgent cesarean section with epidural anesthesia without producing unwanted side-effects.

A shocking admission: patient exclusion from intensive care therapy

OBJECTIVE

Quantitative description of intensive care unit (ICU) triage practice.

METHODS

Prospective audit of patients refused access to the Waikato ICU over a one year period.

RESULTS

For the period August 2003 to September 2004, 280 referrals to the ICU were refused. Ninety five referrals (34%) were refused on the grounds that the patient would be too sick to benefit from ICU treatment, and 124 (44%) were considered too well. Sixty one referrals were declined on the basis that there was insufficient resource (beds or nurses).

CONCLUSIONS

In our hospital a significant number of patients referred for intensive care therapy are refused access. Triage occurs as a result of resource limitation and/or because the patient is seen as too sick or too well to benefit. Despite this being part of our daily practice, it has been, to date, poorly quantified. Until the process is demystified it cannot be understood or debated by doctors, the public and political figures.

Early rheumatoid arthritis in African-Americans: the CLEAR Registry

African-Americans have been under-represented in genetic studies of rheumatoid arthritis (RA) susceptibility and severity. Genetic and non-genetic factors influencing the radiographic severity of RA and its response to treatment are poorly understood, particularly in African-Americans. The Consortium for the Longitudinal Evaluation of African-Americans with early RA (CLEAR) Registry, a collaborative effort among four institutions in the southeast USA, will hopefully provide a useful resource to study these issues.

Water safety plans for small systems: a model for applying HACCP concepts for cost-effective monitoring in developing countries

The development of water safety plans (WSPs) for small systems should be based on a thorough understanding of the relationships between risk factors and contamination events. This can be achieved through the use of well-designed assessments of water quality that provide better evidence to support the identification of control measures, performance limits, monitoring parameters and verification procedures. Training of community operators is critical to the success of the WSP and the understanding gained from the assessments provides a sound basis for addressing these needs. The WSP approach provides for more effective control of water quality and the use of targeted assessments is cost-effective in improving the design of WSPs.

Method for qualifying microbial removal performance of 0.1 micron rated filters. Part IV: Retention of hydrogenophaga pseudoflava (ATCC 700892) and Ralstonia pickettii (ATCC 700591) by 0.2 and 0.22 micron rated filters

Ralstonia pickettii has emerged as a bioburden microorganism of considerable importance in pharmaceutical processes utilizing conventional 0.2 or 0.22 micron rated "sterilizing grade" filters. In this article, we re-evaluated and studied the retention efficiencies of 0.2 micron rated nylon 6.6 and 0.22 microns rated modified polyvinylidene fluoride (PVDF) filters for Hydrogenophaga pseudoflava (ATCC 700892) and R. pickettii (ATCC 700591). Out of a total of forty-four 0.2/0.22 micron rated filters discs tested in this study (spanning different challenge fluids, different challenge conditions, and different filter types), H. pseudoflava penetration was observed for every filter disc tested. Log titer reduction (LTR) values ranged from 0.3 to 2.0 logs for 20-48 hour challenges conducted in Water for Injection (WFI), and 3.8-7.1 logs for 6-hour challenges conducted in Minimal Media Davis (MMD). For 0.2 micron nylon 6.6 filter discs, penetration by R. pickettii was observed only in WFI challenges and was dependent on the culture and challenge conditions used. Penetration by R. pickettii was also restricted to only those membrane discs that were very close to the filter manufacturer's production integrity test (the Quantitative Bubble Point, QBP, test) limit. Where R. pickettii penetration was observed, LTR values were significantly higher than those observed for H. pseudoflava with the same filter discs. This study: 1) supports the use of H. pseudoflava as a worst-case challenge model for R. pickettii in process- and product-specific bacterial retention testing; 2) provides experimental evidence, for the first time, for the need to include filter membrane lots that have a physical integrity test value at or near the filter manufacturer's production (lower) limit in these tests; and 3) demonstrates how a standardized membrane integrity test (such as the QBP test) can be used select such "worst-case" membranes and to verify the inclusion of such "worst-case" membranes in these tests, thus serving as the link between the membrane disc used in bacterial retention validation testing and the production process filter.