New System for Digital to Analog Transformation and Reconstruction of 12-Lead ECGs

Introduction

We describe initial validation of a new system for digital to analog conversion (DAC) and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer''s 12-lead ECG hardware/software into that of any other.

Materials and Methods

To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long) in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data.

Results

The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer''s analog to digital converter (ADC) as the original digitization, and 28.4 µV per channel when it involved a different manufacturer''s ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout.

Conclusion

Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud-based servers.     

Histone Modifications Are Associated with Δ9-Tetrahydrocannabinol-mediated Alterations in Antigen-specific T Cell Responses

Marijuana is one of the most abused drugs due to its psychotropic effects. Interestingly, it is also used for medicinal purposes. The main psychotropic component in marijuana, Δ⁹-tetrahydrocannabinol (THC), has also been shown to mediate potent anti-inflammatory properties. Whether the immunomodulatory activity of THC is mediated by epigenetic regulation has not been investigated previously. In this study, we employed ChIP-Seq technology to examine the in vivo effect of THC on global histone methylation in lymph node cells of mice immunized with a superantigen, staphylococcal enterotoxin B. We compared genome-wide histone H3 Lys-4, Lys-27, Lys-9, and Lys-36 trimethylation and histone H3 Lys-9 acetylation patterns in such cells exposed to THC or vehicle. Our results showed that THC treatment leads to the association of active histone modification signals to Th2 cytokine genes and suppressive modification signals to Th1 cytokine genes, indicating that such a mechanism may play a critical role in the THC-mediated switch from Th1 to Th2. At the global level, a significant portion of histone methylation and acetylation regions were altered by THC. However, the overall distribution of these histone methylation signals among the genomic features was not altered significantly by THC, suggesting that THC activates the expression of a subset of genes while suppressing the expression of another subset of genes through histone modification. Functional classification of these histone marker-associated genes showed that these differentially associated genes were involved in various cellular functions, from cell cycle regulation to metabolism, suggesting that THC had a pleiotropic effect on gene expression in immune cells. Altogether, the current study demonstrates for the first time that THC may modulate immune response through epigenetic regulation involving histone modifications.     

Isolation of a naturally-occurring nickel resistance plasmid from a rare hypersaline estuary (Laguna Madre,Texas, USA) for potential use as a bio-indicator of metal contamination

Metal-resistant bacteria were isolated from sediments of the Laguna Madre, a rare hypersaline estuary impacted by many anthropogenic compounds, including various metals and metalloids. Bacteria were initially isolated on nutrient agar supplemented with NaCl; random isolates (n = 100) were tested for metal resistance toward zinc, nickel, chromium, and cadmium using a pour plate disc assay. Metal-resistant cultures were assayed for plasmids that contained naturally-occurring heavy metal resistance genes. Putative metal-resistance plasmids were tested for metal-resistance efficacy by transforming a metal-sensitive strain of Escherichia coli. Polymerase Chain Reaction (PCR) primers were designed to detect cnrA, part of a nickel–cobalt resistance gene cluster, and restriction endonuclease digests were performed to detect restriction sites within the plasmid. Results showed that many bacterial isolates tested were resistant toward most of the metals used in this study. Among tested bacteria cultures, 34 were resistant to zinc, 64 were resistant to chromium, and 51 resistant to cadmium. Only 8 cultures were resistant to nickel; however, most bacteria were found to be resistant to more than one metal. Several plasmids were found from the bacteria isolates. One plasmid, designated pDZ5, was isolated from a bacterium identified as Bacillus pumilus by 16S rRNA sequencing. Plasmid pDZ5 conferred nickel resistance to the metal-sensitive E. coli strain and was found to contain cnrA as confirmed by PCR amplification. Plasmid pDZ5 was successfully cut with restriction enzymes for potential ligation with reporter genes. The presence, abundance and expression of pDZ5 may prove to be a useful bio-indicator of metal contamination, specifically nickel pollution, in the Laguna Madre due to the fewer number of bacteria that were nickel-resistant compared to other metals.     

The cost-effectiveness of early access to HIV services and starting cART in the UK 1996-2008

Aim

To calculate use, cost and cost-effectiveness of people living with HIV (PLHIV) starting routine treatment and care before starting combination antiretroviral therapy (cART) and PLHIV starting first-line 2NRTIs+NNRTI or 2NRTIs+PI_boosted, comparing PLHIV with CD4≤200 cells/mm3 and CD4>200 cells/mm3. Few studies have calculated the use, cost and cost-effectiveness of routine treatment and care before starting cART and starting cART above and below CD4 200 cells/mm3.

Methods

Use, costs and cost-effectiveness were calculated for PLHIV in routine pre-cART and starting first-line cART, comparing CD4≤200 cells/mm3 with CD4>200 cells/mm3 (2008 UK prices).

Results

cART naïve patients CD4≤200 cells/mm3 had an annual cost of £6,407 (95%CI £6,382 to £6,425) PPY compared with £2,758 (95%CI £2,752 to £2,761) PPY for those with CD4>200 cells/mm3; cost per life year gained of pre-cART treatment and care for those with CD4>200 cells/mm3 was £1,776 (cost-saving to £2,752). Annual cost for starting 2NRTIs+NNRTI or 2NRTIs+PI_boosted with CD4≤200 cells/mm3 was £12,812 (95%CI £12,685–£12,937) compared with £10,478 (95%CI £10,376–£10,581) for PLHIV with CD4>200 cells/mm3. Cost per additional life-year gained on first-line therapy for those with CD4>200 cells/mm3 was £4639 (£3,967 to £2,960).

Conclusion

PLHIV starting to use HIV services before CD4≤200 cells/mm3 is cost-effective and enables them to be monitored so they start cART with a CD4>200 cells/mm3, which results in better outcomes and is cost-effective. However, 25% of PLHIV accessing services continue to present with CD4≤200 cells/mm3. This highlights the need to investigate the cost-effectiveness of testing and early treatment programs for key populations in the UK.     

Expression of cell surface zinc transporter LIV1 in triple negative breast cancer is an indicator of poor prognosis and therapy failure

Triple negative breast cancers (TNBC) are an aggressive molecular subtype of breast carcinoma (BC) identified by the lack of receptor expression for estrogen, progesterone, & human epidermal growth factor receptor-2. Lack of tangible drug targets warrants further research in TNBC. LIV1, is a zinc (Zn) transporter known to be overexpressed in few cancer types including BCs. Recently, in the United States of America, FDA approved the use of a new drug targeting LIV1, antibody drug conjugate SGN-LIV1A for treatment of TNBC patients. Though LIV1 also has a role in modulating immune cells by its differential transport of Zn, a correlation between the tumor cell expression of LIV1 and immune cell infiltrations were scantily reported. Further adequate baseline data on LIV1 expression in other populations have not been documented. Our objective was to screen a large Indian cohort of TNBC patient samples for LIV1, categorize the immune cell infiltration using CD4/CD8 expression and correlate the findings with therapy outcomes. Further, we also investigated for LIV1 expression in matched samples of primary & secondary tumors; pre & postchemotherapy in TNBC patients. Results showed an elevated expression of LIV1 in TNBC samples as compared to adjacent normal, the mean Q scores being 183.06 ± 6.39 and 120.78 ± 7.37 (p < 0.0001), respectively. Similarly, LIV1 levels were elevated in secondary tumors than primary & in patient samples postchemotherapy as compared to naïve. In the TNBC cohort, using automated method, cell morphology parameters were computed and analysis showed LIV1 levels were elevated in grade 3 TNBC samples presenting with altered cell morphology parameters namely cell size, cell perimeter, & nucleus size. Thus indicating LIV1 expressing TNBC samples portrayed an aggressive phenotype. Finally, TNBC patients with 3+ staining intensity showed poor survival (4.44 year) as compared to patients with 2+ LIV1 expression (5.47 year), emphasizing that LIV1 expression is a poor prognostic factor in TNBC. In conclusion, the study reports elevated expression of LIV1 in a large Indian TNBC cohort; high expression is a poor prognostic factor and correlated with aggressive disease and indicating the need for LIV1 targeted therapies.     

Length‐weight relationship of two Ambassid fish species,Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba,Southern Western Ghats,India

The present study provides the length‐weight relationships (LWRs) of two Ambassid fish species, Parambassis dayi (Bleeker, 1874) and Parambassis thomassi (Day, 1870) from River Pamba in Southern Western Ghats, India. Fishes were collected on a monthly basis between April 2014 to March 2015 using gill nets (1.0–3.0 cm), cast nets (1.0–2.0 cm) and seine nets (1.0 cm). The b values in the LWRs were estimated as 3.01 for P. dayi and 3.14 for P. thomassi. No previous information is available on LWRs for these two species in FishBase.     

Fabrication of chitin-chitosan/nano ZrO(2) composite scaffolds for tissue engineering applications

The urge to repair and regenerate natural tissues can now be satisfactorily fulfilled by various tissue engineering approaches. Chitin and chitosan are the most widely accepted biodegradable and biocompatible materials subsequent to cellulose. The incorporation of nano ZrO₂ onto the chitin-chitosan scaffold is thought to enhance osteogenesis. Hence a nanocomposite scaffold was fabricated by lyophilization technique using chitin-chitosan with nano ZrO₂. The prepared nanocomposite scaffolds were characterized using SEM, FTIR, XRD and TGA. In addition, the swelling, degradation, biomineralization, cell viability and cell attachment of the composite scaffolds were also evaluated. The results demonstrated better swelling and controlled degradation in comparison to the control scaffold. Cell viability studies proved the non toxic nature of the nanocomposite scaffolds. Cells were found to be attached to the pore walls and spread uniformly throughout the scaffolds. All these results suggested that the developed nanocomposite scaffolds possess the prerequisites for tissue engineering scaffolds and could be used for various tissue engineering applications.     

Identification of four novel genes contributing to familial elevated plasma HDL cholesterol in humans

While genetic determinants strongly influence HDL cholesterol (HDLc) levels, most genetic causes underlying variation in HDLc remain unknown. We aimed to identify novel rare mutations with large effects in candidate genes contributing to extreme HDLc in humans, utilizing family-based Mendelian genetics. We performed next-generation sequencing of 456 candidate HDLc-regulating genes in 200 unrelated probands with extremely low (≤10th percentile) or high (≥90th percentile) HDLc. Probands were excluded if known mutations existed in the established HDLc-regulating genes ABCA1, APOA1, LCAT, cholesteryl ester transfer protein (CETP), endothelial lipase (LIPG), and UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 2 (GALNT2). We identified 93 novel coding or splice-site variants in 72 candidate genes. Each variant was genotyped in the proband’s family. Family-based association analyses were performed for variants with sufficient power to detect significance at P < 0.05 with a total of 627 family members being assessed. Mutations in the genes glucokinase regulatory protein (GCKR), RNase L (RNASEL), leukocyte immunoglobulin-like receptor 3 (LILRA3), and dynein axonemal heavy chain 10 (DNAH10) segregated with elevated HDLc levels in families, while no mutations associated with low HDLc. Taken together, we have identified mutations in four novel genes that may play a role in regulating HDLc levels in humans.     

Development of Indicators for Patient Care and Monitoring Standards for Secondary Health Care Services of Mumbai

Background

The Qualitative aspect of health care delivery is one of the major factors in reducing morbidity and mortality in a health care setup. The expanding suburban secondary health care delivery facilities of the Municipal Corporation of Greater Mumbai are an important part of the healthcare backbone of Mumbai and therefore the quality of care delivered here needed standardization.

Material and Methods

The project was completed over a period of one year from Jan to Dec, 2013 and implemented in three phases. The framework with components and sub-components were developed and formats for data collection were standardized. The benchmarks were based on past performance in the same hospital and probability was used for development of normal range. An Excel spreadsheet was developed to facilitate data analysis.

Results

The indicators comprise of 3 components - Statutory Requirements, Patient care & Cure and Administrative efficiency. The measurements made, pointed to the broad areas needing attention.

Conclusion

The Indicators for patient care and monitoring standards can be used as a self assessment tool for health care setups for standardization and improvement of delivery of health care services.