Association between body mass index and stroke severity in acute ischaemic stroke with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

The objective of this study was to investigate the association between body mass index (BMI) and both initial stroke severity at presentation and functional outcomes after acute ischaemic stroke (AIS) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

Patients were categorized on the basis of their BMI into underweight (BMI <18.5, n = 111), normal (18.5 ≤ BMI <25, n = 1036) and overweight to obese (BMI ≥25, n = 472) groups. Initial stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score and functional outcomes were assessed using the modified Rankin Scale score at discharge. The differences in stroke severity and functional outcomes were compared between groups using robust log-linear regression with a Poisson distribution and binary logistic regression analysis.

RESULTS

A total of 1619 AIS patients with NVAF from six hospitals were included. Compared with the NIHSS scores [median 5, interquartile range (IQR) 2-14] of normal-weight patients, the NIHSS scores (median 9, IQR 4-19) of underweight patients were more likely to be higher, whereas those of overweight to obese patients were lower (median 4, IQR 1-12) (P < 0.001). In terms of functional outcomes after stroke, underweight patients had a higher risk of poor functional outcomes (odds ratio 1.78, 95% confidence interval 1.09-2.56, P = 0.01) but overweight to obese patients had no significant difference in functional outcomes compared with normal-weight patients.

CONCLUSION

An inverse association was found between BMI and stroke severity in AIS patients with NVAF. This suggests the presence of an obesity paradox for short-term outcomes in patients with NVAF.

Comparative genotyping of Streptococcus mutans by repetitive extragenic palindromic polymerase chain reaction and multilocus sequence typing

The genetic diversity of Streptococcus mutans has been extensively studied using a variety of genotyping methods. Repetitive extragenic palindromic-polymerase chain reaction (rep-PCR) is a genotyping approach used for screening large numbers of bacterial isolates. This two-part study used multilocus sequence typing (MLST) analysis to evaluate genotypes previously identified as unique using rep-PCR. In part one, an isolate was selected from each of the 22 S. mutans rep-PCR genotype groups representing 8000 clinical isolates. For part two, four additional isolates were selected from the six most commonly occurring genotype groups (GG) for further analysis. Real-time PCR was performed using eight housekeeping S. mutans gene loci and the amplicons were sequenced. Sequence data analysis was performed using CLC DNA Workbench and alleles were compared with the PubMLST database for Oral Streptococcus using the Nakano scheme. Concatenated sequences were evaluated with MEGA using a minimum evolution method with bootstrap. All 22 rep-PCR genotypes were unique by MLST analysis. Within rep-PCR GGs, MLST matched rep-PCR in three groups demonstrating clonality; three groups exhibited more diversity with MLST. The discovery of three clonal groups is unique to this study and suggests that S. mutans genotypes are shared between unrelated subjects. Furthermore, MLST defined 19 new alleles and 26 new sequence types that have been confirmed and registered with PubMLST. Methods for processing were streamlined and a process for using MLST with rep-PCR is suggested. In conclusion, MLST verified that rep-PCR is a reliable and cost-effective method for screening large numbers of S. mutans strains for epidemiological study.

Genetic diversity of plaque mutans streptococci with rep-PCR

Mutans streptococci (MS) are key organisms associated with the etiology of dental caries. Using probabilities that were tested by oversampling, we designed this study to determine the minimal number of MS isolates from an individual required to evaluate diversity of genotypes. MS isolates were genotyped by repetitive extragenic palindromic-polymerase chain-reaction (rep-PCR). Analysis of 20 isolates from individuals resulted in a mean of 1.6 and 2.4 genotypes in children (N = 12) and adults (N = 10), respectively. In a follow-up study, reducing the number of isolates to 7-10 resulted in a theoretical probability of up to 78% for detecting up to 4 genotypes. A mean of 1.5 genotypes was found in 35 children and 10 adults. These findings provide evidence for the design of studies of MS genotyping that can serve as a model for the analysis of genotypes within individuals.

Asymptomatic kidney stones in long-term survivors of childhood acute lymphoblastic leukemia

We hypothesized an association between renal calculi and bone mineral density (BMD) deficits, shown in adults, exists in survivors of childhood acute lymphoblastic leukemia (ALL). Thus, we analyzed the associations between quantitative computed tomography (QCT)-determined renal calcifications and clinical parameters (gender, race, age at diagnosis and age at the time of QCT), BMD, treatment exposures and Tanner stage. We investigated the associations between stone formation and nutritional intake, serum and urinary calcium and creatinine levels, and urinary calcium/creatinine ratio. Exact chi(2)-test was used to compare categorical patient characteristics, and the Wilcoxon-Mann-Whitney test to compare continuous measurements. Of 424 participants, 218 (51.4%) were males; 371 (87.5%) were nonblack. Most (n=270; 63.7%) were >or=3.5 years at ALL diagnosis. Mean (s.d.) and median (range) BMD Z-scores of the entire cohort were -0.4 (1.2) and -0.5 (-3.9 to 5.1), respectively. Nineteen participants (10 males; 10 Caucasians) had kidney stones (observed prevalence of 4.5%; 19/424) with a significant negative association between stone formation and body habitus (body mass index, P=0.003). Stone formation was associated with treatment protocol (P=0.009) and treatment group (0.007). Thus, kidney stones in childhood ALL survivors could herald the future deterioration of renal function and development of hypertension. Long-term follow-up imaging may be warranted in these patients to monitor for progressive morbidity.

Global detection of molecular changes reveals concurrent alteration of several biological pathways in nonsmall cell lung cancer cells

To identify the molecular changes that occur in non-small cell lung carcinoma (NSCLC), we compared the gene expression profile of the NCI-H292 (H292) NSCLC cell line with that of normal human tracheobronchial epithelial (NHTBE) cells. The NHTBE cells were grown in a three-dimensional organotypic culture system that permits maintenance of the normal pseudostratified mucociliary phenotype characteristic of bronchial epithelium in vivo. Microarray analysis using the Affymetrix oligonucleotide chip U95Av2 revealed that 1,683 genes showed a >1.5-fold change in expression in the H292 cell line relative to the NHTBE cells. Specifically, 418 genes were downregulated and 1,265 were upregulated in the H292 cells. The expression data for selected genes were validated in several different NSCLC cell lines using quantitative real-time PCR and Western analysis. Further analysis of the differentially expressed genes indicated that WNT responses, apoptosis, cell cycle regulation and cell proliferation were significantly altered in the H292 cells. Functional analysis using fluorescence-activated cell sorting confirmed concurrent changes in the activity of these pathways in the H292 line. These findings show that (1) NSCLC cells display deregulation of the WNT, apoptosis, proliferation and cell cycle pathways, as has been found in many other types of cancer cells, and (2) that organotypically cultured NHTBE cells can be used as a reference to identify genes and pathways that are differentially expressed in tumor cells derived from bronchogenic epithelium.

Activation of ErbB2 during wallerian degeneration of sciatic nerve

We used anti-phosphopeptide-immunodetecting antibodies as immunohistochemical reagents to define the location and activity state of p185(erbB2) during Wallerian degeneration. Nerve damage induces a phosphorylation event at Y1248, a site that couples p185(erbB2) to the Ras-Raf-MAP kinase signal transduction pathway. Phosphorylation of p185(erbB2) occurs within Schwann cells and coincides in time and space with Schwann cell mitotic activity, as measured by bromodeoxyuridine uptake. These visual images of receptor autophosphorylation link activation of p185(erbB2) to the Schwann cell proliferation that accompanies nerve regeneration.