Telomeres and atherosclerosis

Abstract

In humans and other multicellular organisms that have an extended lifespan, the leading causes of death are atherosclerotic cardiovascular disease and cancer. Experimental and clinical evidence indicates that these age-related disorders are linked through dysregulation of telomere homeostasis. Telomeres are DNA protein structures located at the terminal end of chromosomes and shorten with each cycle of cell replication, thereby reflecting the biological age of an organism. Critically shortened telomeres provoke cellular senescence and apoptosis, impairing the function and viability of a cell. The endothelial cells within atherosclerotic plaques have been shown to display features of cellular senescence. Studies have consistently demonstrated an association between shortened telomere length and coronary artery disease (CAD).

Several of the CAD risk factors and particularly type 2 diabetes are linked to telomere shortening and cellular senescence. Our interest in telomere biology was prompted by the high incidence of premature CAD and diabetes in a subset of our population, and the hypothesis that these conditions are premature-ageing syndromes. The assessment of telomere length may serve as a better predictor of cardiovascular risk and mortality than currently available risk markers, and anti-senescence therapy targeting the telomere complex is emerging as a new strategy in the treatment of atherosclerosis. We review the evidence linking telomere biology to atherosclerosis and discuss methods to preserve telomere length.

FPGA Based High Speed Data Acquisition System for Electrical Impedance Tomography

Electrical Impedance Tomography (EIT) systems are used to image tissue bio-impedance. EIT provides a number of features making it attractive for use as a medical imaging device including the ability to image fast physiological processes (>60 Hz), to meet a range of clinical imaging needs through varying electrode geometries and configurations, to impart only non-ionizing radiation to a patient, and to map the significant electrical property contrasts present between numerous benign and pathological tissues. To leverage these potential advantages for medical imaging, we developed a modular 32 channel data acquisition (DAQ) system using National Instruments' PXI chassis, along with FPGA, ADC, Signal Generator and Timing and Synchronization modules. To achieve high frame rates, signal demodulation and spectral characteristics of higher order harmonics were computed using dedicated FFT-hardware built into the FPGA module. By offloading the computing onto FPGA, we were able to achieve a reduction in throughput required between the FPGA and PC by a factor of 32:1. A custom designed analog front end (AFE) was used to interface electrodes with our system. Our system is wideband, and capable of acquiring data for input signal frequencies ranging from 100 Hz to 12 MHz. The modular design of both the hardware and software will allow this system to be flexibly configured for the particular clinical application.

An information systems model of the determinants of electronic health record use

OBJECTIVES

The prominence given to universal implementation of electronic health record (EHR) systems in U.S. health care reform, underscores the importance of devising reliable measures of factors that predict medical care providers' use of EHRs. This paper presents an easily administered provider survey instrument that includes measures corresponding to core dimensions of DeLone and McClean's (D & M) model of information system success.

METHODS

Study data came from self-administered surveys completed by 460 primary care providers, who had recently begun using an EHR.

RESULTS

Based upon assessment of psychometric properties of survey items, a revised D&M causal model was formulated that included four measures of the determinants of EHR use (system quality, IT support, ease of use, user satisfaction) and five indicators of provider beliefs about the impact on an individual's clinical practice. A structural equation model was estimated that demonstrated a high level of inter-correlation between the four scales measuring determinants of EHR use. All four variables had positive association with each of the five individual impact measures. Consistent with our revised D&M model, the association of system quality and IT support with the individual impact measures was entirely mediated by ease of use and user satisfaction.

CONCLUSIONS

Survey research provides important insights into provider experiences with EHR. Additional studies are in progress to investigate how the variables constructed for this study are related to direct measures of EHR use.

Micellar Behaviour of Copper Surfactants Derived from Fresh (Untreated) Sesame Oil and Used (Treated at High Temperature) Sesame Oil

Copper soaps have been prepared from fresh and used sesame oils. The formation of copper soaps has been confirmed by spectral technique. Micellar characterization of copper soaps has been studied by density, viscosity and ultrasonic measurements. The apparent molar volume and apparent molar compressibility have been enumerated at constant temperature using these data. The results were used to determine the critical micelle concentration (CMC), soap-solvent interaction. The results of apparent molar volume were discussed in terms of Masson's equation and the results of viscosity data have been discussed in terms of Jones-Dole equation. The CMC values are found to increase with decrease in average molecular weight of the soap. It has been observed that there is a decrease in soap-solvent interaction with the decrease in average molecular weight of copper soap.

Synthesis, Characterization and Antifungal Activities of Copper(II) Soaps and their Complexes Derived from Azadirecta Indica (Neem) and Pongamia Pinnata (Karanj) Oil

Neem (Azadirecta indica) and Karanj (Pongamia pinnata) oils are ecofriendly, non-toxic, completely biodegradable with antiviral, antifungal, and antibacterial properties. The dark green colour Copper(II) soaps derived from Neem and Karanj oil, their greenish brown complexes with ligand 2-amino-6-methyl benzothiazole containing nitrogen and sulphur have been synthesized and characterized by elemental analysis. IR and NMR of complexes suggest that the complexation has taken place successfully. From the analytical data the stoichiometry of the complexes has been observed to be 1:1 (metal-ligand). Copper soaps and their complexes are good anti-fungal agents. The fungi toxicities of the oils, soaps and complexes of neem and karanj have been investigated. The results indicate that the strain of Candida species is susceptible towards complexes of benzothiazole.

Assessment of phylogenetic relationship of rare plant species collected from Saudi Arabia using internal transcribed spacer sequences of nuclear ribosomal DNA

The rare and endangered plants of any country are important genetic resources that often require urgent conservation measures. Assessment of phylogenetic relationships and evaluation of genetic diversity is very important prior to implementation of conservation strategies for saving rare and endangered plant species. We used internal transcribed spacer sequences of nuclear ribosomal DNA for the evaluation of sequence identity from the available taxa in the GenBank database by using the Basic Local Alignment Search Tool (BLAST). Two rare plant species viz, Heliotropium strigosum claded with H. pilosum (98% branch support) and Pancratium tortuosum claded with P. tenuifolium (61% branch support) clearly. However, some species, viz Scadoxus multiflorus, Commiphora myrrha and Senecio hadiensis showed close relationships with more than one species. We conclude that nuclear ribosomal internal transcribed spacer sequences are useful markers for phylogenetic study of these rare plant species in Saudi Arabia.

The incidence and magnitude of fibrinolytic activation in trauma patients

BACKGROUND

Trauma is a global disease, with over 2.5 million deaths annually from hemorrhage and coagulopathy. Overt hyperfibrinolysis is rare in trauma, and is associated with massive fatal injuries. Paradoxically, clinical trials suggest a much broader indication for antifibrinolytics.

OBJECTIVE

To determine the incidence and magnitude of fibrinolytic activation in trauma patients and its relationship to clot lysis as measured by thromboelastometry.

METHODS

A prospective cohort study of 303 consecutive trauma patients admitted between January 2007 and June 2009 was performed. Blood was drawn on arrival for thromboelastometry (TEM) and coagulation assays. Follow-up was until hospital discharge or death. TEM hyperfibrinolysis was defined as maximum clot lysis of > 15%. Fibrinolytic activation (FA) was determined according to plasmin-antiplasmin (PAP) complex and D-dimer levels. Data were collected on demographics, mechanism, severity of injury, and baseline vital signs. The primary outcome measure was 28-day mortality. The secondary outcome measures were 28-day ventilator-free days and 24-h transfusion requirement.

RESULTS

Only 5% of patients had severe fibrinolysis on TEM, but 57% of patients had evidence of 'moderate' fibrinolysis, with PAP complex levels elevated to over twice normal (> 1500 μg L(-1)) without lysis on TEM. TEM detected clot lysis only when PAP complex levels were increased to 30 times normal (P < 0.001) and antiplasmin levels were < 75% of normal. Patients with FA had increased 28-day mortality as compared with those with no FA (12% vs. 1%, P < 0.001), fewer ventilator-free days, and longer hospital stay.

CONCLUSIONS

FA occurs in the majority of trauma patients, and the magnitude of FA correlates with poor clinical outcome. This was not detected by conventional TEM, which is an insensitive measure of endogenous fibrinolytic activity.

Bone marrow negative visceral leishmaniasis in an adolescent male

Visceral Leishmaniasis or Kala Azar is endemic in certain regions of India. In endemic areas, the constellation of fever, progressive weight loss, weakness, pronounced splenomegaly, anemia, leukopenia, and hypergammaglobulinemia is highly suggestive of visceral leishmaniasis. Demonstration of the parasite in liver, splenic or bone marrow aspirates is confirmatory. We present a case in which Leishmania donovani (LD) bodies were demonstrated on splenic aspirate. We were unable to demonstrate LD bodies on bone marrow aspiration.

Risk of cancer other than breast or ovarian in individuals with BRCA1 and BRCA2 mutations

The risks of cancers other than breast and ovarian amongst BRCA1 and BRCA2 mutation carriers are based on relatively few family based studies with the risk of specific cancers tested in population based samples of cancers from founder populations. We assessed risks of "other cancers" in 268 BRCA1 families and 222 BRCA2 families using a person years at risk analysis from 1975 to 2005. Cancer confirmations were overall higher than in previous family based studies at 64%. There was no overall increase in risk for BRCA1 carriers although oesophagus had a significant increased RR of 2.9 (95% CI 1.1-6.0) and stomach at 2.4 (95% CI 1.2-4.3), these were based mainly on unconfirmed cases. For BRCA2 increased risks for cancers of the pancreas (RR 4.1, 95% CI 1.9-7.8) and prostate (RR 6.3, 95% CI 4.3-9.0) and uveal melanoma (RR 99.4, 95% CI 11.1-359.8) were confirmed. Possible new associations with oesophagus (RR 4.1, 95% CI 1.9-7.8) and stomach (RR 2.7, 95% CI 1.3-4.8) were detected but these findings should be treated with caution due to lower confirmation rates. In contrast to previous research a higher risk of prostate cancer was found in males with mutations in the BRCA2 OCCR region. The present study strengthens the known links between BRCA2 and pancreatic and prostate cancer, but throws further doubt onto any association with BRCA1. New associations with upper gastro-intestinal malignancy need to be treated with caution and confirmed by large prospective studies.

Early diagnosis of typhoid fever by nested PCR for flagellin gene of Salmonella enterica serotype Typhi

BACKGROUND & OBJECTIVES

Typhoid fever caused by Salmonella Typhi continues to be a major health problem in spite of the use of antibiotics and the development of newer antibacterial drugs. Inability to make an early laboratory diagnosis and resort to empirical therapy, often lead to increased morbidity and mortality in cases of typhoid fever. This study was aimed to optimize a nested PCR for early diagnosis of typhoid fever and using it as a diagnostic tool in culture negative cases of suspected typhoid fever.

METHODS

Eighty patients with clinical diagnosis of typhoid fever and 40 controls were included in the study. The blood samples collected were subjected to culture, Widal and nested PCR targeting the flagellin gene of S. Typhi.

RESULTS

The sensitivity of PCR on blood was found to be 100 per cent whereas the specificity was 76.9 per cent. The positive predictive value (PPV) of PCR was calculated to be 76.9 per cent with an accuracy of 86 per cent. None of the 40 control samples gave a positive PCR.

INTERPRETATION & CONCLUSIONS

Due to its high sensitivity and specificity nested PCR can be used as a useful tool to diagnose clinically suspected, culture negative cases of typhoid fever.