Low exercise blood pressure and risk of cardiovascular events and all-cause mortality: Systematic review and meta-analysis

Objective

The independent prognostic significance of abnormally low systolic blood pressure (SBP) during exercise stress testing (LowExBP) across different clinical and exercise conditions is unknown. We sought by systematic review and meta-analysis to determine the association between cardiovascular/all-cause outcomes and LowExBP across different patient clinical presentations, exercise modes, exercise intensities and categories of LowExBP.

Methods

Seven online databases were searched for longitudinal studies reporting the association of LowExBP with risk of fatal and non-fatal cardiovascular events and/or all-cause mortality. LowExBP was defined as either: SBP drop below baseline; failure to increase >10 mmHg from baseline or; lowest SBP quantile among reporting studies.

Results

After review of 13,257 studies, 19 that adjusted for resting SBP were included in the meta-analysis, with a total of 45,895 participants (average follow-up, 4.4 ± 3.0 years). For the whole population, LowExBP was associated with increased risk for fatal and non-fatal cardiovascular events and all-cause mortality (hazard ratio [HR]: 2.01, 95% confidence interval [CI]: 1.59–2.53, p < 0.001). In continuous analyses, a 10 mmHg decrease in exercise SBP was associated with higher risk (n = 9 HR: 1.13, 95% CI: 1.06–1.20, p < 0.001). LowExBP was associated with increased risk regardless of clinical presentation (coronary artery disease, heart failure, hypertrophic cardiomyopathy or peripheral artery disease), exercise mode (treadmill or bike), exercise intensity (moderate or maximal), or LowExBP category (all p < 0.05). However, bias toward positive results was apparent (Eggers test p < 0.001 and p = 0.009).

Conclusion

Our data show that irrespective of clinical or exercise conditions, LowExBP independently predicts fatal and non-fatal cardiovascular events and all-cause mortality.     

Preictal Dynamics of EEG Complexity in Intracranially Recorded Epileptic Seizure: A Case Report

Recent findings suggest that neural complexity reflecting a number of independent processes in the brain may characterize typical changes during epileptic seizures and may enable to describe preictal dynamics. With respect to previously reported findings suggesting specific changes in neural complexity during preictal period, we have used measure of pointwise correlation dimension (PD2) as a sensitive indicator of nonstationary changes in complexity of the electroencephalogram (EEG) signal. Although this measure of complexity in epileptic patients was previously reported by Feucht et al (Applications of correlation dimension and pointwise dimension for non-linear topographical analysis of focal onset seizures. Med Biol Comput. 1999;37:208–217), it was not used to study changes in preictal dynamics. With this aim to study preictal changes of EEG complexity, we have examined signals from 11 multicontact depth (intracerebral) EEG electrodes located in 108 cortical and subcortical brain sites, and from 3 scalp EEG electrodes in a patient with intractable epilepsy, who underwent preoperative evaluation before epilepsy surgery. From those 108 EEG contacts, records related to 44 electrode contacts implanted into lesional structures and white matter were not included into the experimental analysis.The results show that in comparison to interictal period (at about 8–6 minutes before seizure onset), there was a statistically significant decrease in PD2 complexity in the preictal period at about 2 minutes before seizure onset in all 64 intracranial channels localized in various brain sites that were included into the analysis and in 3 scalp EEG channels as well. Presented results suggest that using PD2 in EEG analysis may have significant implications for research of preictal dynamics and prediction of epileptic seizures.     

Cytotoxicity of acetylcholinesterase reactivators evaluated in vitro and its relation to their structure

The development of acetylcholinesterase reactivators, i.e., antidotes against organophosphorus poisoning, is an important goal of defense research. The aim of this study was to compare cytotoxicity and chemical structure of five currently available oximes (pralidoxime, trimedoxime, obidoxime, methoxime, and asoxime) together with four perspective oximes from K-series (K027, K074, K075, and K203). The cytotoxicity of tested substances was measured using two methods – colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and impedance based real-time cytotoxicity assay – in three different cell lines (HepG2, ACHN, and NHLF). Toxicity was subsequently expressed as toxicological index IC₅₀. The tested compounds showed different cytotoxicity ranging from 0.92 to 40.06?mM. In HepG2 cells, K027 was the least and asoxime was the most toxic reactivator. In ACHN and NHLF cell lines, trimedoxime was the compound with the lowest adverse effects, whereas the highest toxicity was found in methoxime-treated cells. The results show that at least five structural features affect the reactivators’ toxicity such as the number of oxime groups in the molecule, their position on pyridinium ring, the length of carbon linker, and the oxygen substitution or insertion of the double bond into the connection chain. Newly synthetized oximes with IC₅₀?≥?1?mM evaluated in this three cell lines model might appear suitable for further testing.     

Arylazopyrazole AAP1742 Inhibits CDKs and Induces Apoptosis in Multiple Myeloma Cells via Mcl‐1 Downregulation

Inhibitors of cyclin‐dependent kinases 9 have been developed as potential anticancer drugs for the treatment of multiple myeloma. We have previously prepared a library of arylazo‐3,5‐diaminopyrazole inhibitors of CDKs. Here, we describe a novel member, AAP1742 (CDK9 inhibition with IC₅₀ = 0.28 μm ), that reduces the viability of multiple myeloma cell lines in low micromolar concentrations. Consistent with inhibition of CDK9, AAP1742 decreases the phosphorylation of RNA polymerase II and inhibits mRNA synthesis of anti‐apoptotic proteins Mcl‐1, Bcl‐2, and XIAP, followed by apoptosis in the RPMI‐8226 cell line in a dose‐ and a time‐dependent manner. These results are consistent with the biochemical profile of AAP1742 and further suggest cellular inhibition of CDK9 as a possible target for anticancer drugs.     

Adherence to osteoporosis guideline: survey among Czech general practitioners

Rationale and objectives

General practitioners (GPs) play an important role in management of patients at risk of osteoporosis (OP). The objectives were to assess (1) knowledge about OP and use of OP clinical guideline in comparison with other information sources and (2) association between the use of individual information sources and knowledge and self-reported quality of care among GPs.

Methods

Survey among random sample of Czech GPs was performed to find out their attitudes and role in OP management. The return rate of the postal questionnaire was 38% (525 respondents). Quality of care was assessed using three indicators: suspicion on OP, referral to the specialist and initial check-up.

Results

Respondents (median age 52 years, 59% women) had a very good knowledge of several risk factors, while others, namely low body mass index, history of hip fracture in mother and smoking were perceived as risk factors by only 40%, 45% and 55% of respondents, respectively. 10% of GPs stated the correct answer regarding daily calcium intake recommended for postmenopausal women. The OP guideline was considered accessible by 83% of respondents and used repeatedly by 54%. Use of the guideline correlated positively with knowledge score (P < 0.001), while use of each individual other source of information did not. Use of the guideline correlated with all three indicators of quality of care. Use of each other information source correlated only with a maximum of two indicators.

Conclusion

We identified areas of insufficient knowledge that should be targeted in educational activities for GPs. It is recommended to further motivate GPs to use their clinical guidelines regularly.     

Rapid Detection and Identification of Mucormycetes in Bronchoalveolar Lavage Samples from Immunocompromised Patients with Pulmonary Infiltrates by Use of High-Resolution Melt Analysis

Rapid differential diagnostics of pulmonary infiltrates suspected of invasive fungal disease in an immunocompromised host and early initiation of effective antifungal therapy are crucial for patient outcomes. There are no serological tests available to detect mucormycetes; therefore, PCR-based methods are highly suitable. We validated our previously published PCR followed by high-resolution melt analysis (PCR/HRMA) to detect Rhizopus spp., Rhizomucor pusillus, Lichtheimia corymbifera, and Mucor spp. in bronchoalveolar lavage (BAL) samples from immunocompromised patients who were at risk of invasive fungal disease. All PCR/HRMA-positive samples were retested using novel real-time quantitative PCR (RQ PCR) assays specific to the species identified. In total, between January 2009 and December 2012 we analyzed 99 BAL samples from 86 patients with pulmonary abnormalities using PCR/HRMA. Ninety (91%) BAL samples were negative, and 9 (9%) samples were positive. The sensitivity and specificity of PCR/HRMA were 100% and 93%, respectively. By combining the positive results of PCR/HRMA with positive RQ PCR results, the specificity was raised to 98%. PCR/HRMA, due to its high negative predictive value (99%), represents a fast and reliable tool for routine BAL sample screening for the differential diagnosis of pulmonary infiltrates in immunocompromised patients for the four most clinically important mucormycetes.     

Genome-wide screening of DNA copy number alterations in cervical carcinoma patients with CGH+SNP microarrays and HPV-FISH

Alterations in the genome that lead to changes in DNA sequence copy number are characteristic features of solid tumors. We used CGH+SNP microarray and HPV-FISH techniques for detailed screening of copy number alterations (CNAs) in a cohort of 26 patients with cervical carcinoma (CC). This approach identified CNAs in 96.2% (25/26) of tumors. Array-CGH discovered CNAs in 73.1% (19/26) of samples, HPV-FISH experiments revealed CNAs in additional 23.1% (6/26) of samples. Common gains of genetic sequences were observed in 3q (50.0%), 1q (42.4%), 19q (23.1%), while losses were frequently found in 11q (30.8%), 4q (23.1%) and 13q (19.2%). Chromosomal regions involved in loss of heterozygosity were observed in 15.4% of samples in 8q21, 11q23, 14q21 and 18q12.2. Incidence of gain 3q was associated with HPV 16 and HPV 18 positive samples and simultaneous presence of gain 1q (P = 0.033). We did not found a correlation between incidence of CNAs identified by array-CGH and HPV strain infection and incidence of lymph node metastases. Subsequently, HPV-FISH was used for validation of array-CGH results in 23 patients for incidence of hTERC (3q26) and MYC (8q24) amplification. Using HPV-FISH, we found chromosomal lesions of hTERC in 87.0% and MYC in 65.2% of specimens. Our findings confirmed the important role of HPV infection and specific genomic alterations in the development of invasive cervical cancer. This study also indicates that CGH+SNP microarrays allow detecting genome-wide CNAs and copy-neutral loss of heterozygosity more precisely, however, it may be less sensitive than FISH in samples with low level clonal CNAs.