Emerging Concepts of Mechanisms Controlling Cardiac Tension: Focus on Familial Dilated Cardiomyopathy (DCM) and Sarcomere-Directed Therapies

Novel therapies for the treatment of familial dilated cardiomyopathy (DCM) are lacking. Shaping research directions to clinical needs is critical. Triggers for the progression of the disorder commonly occur due to specific gene variants that affect the production of sarcomeric/cytoskeletal proteins. Generally, these variants cause a decrease in tension by the myofilaments, resulting in signaling abnormalities within the micro-environment, which over time result in structural and functional maladaptations, leading to heart failure (HF). Current concepts support the hypothesis that the mutant sarcomere proteins induce a causal depression in the tension-time integral (TTI) of linear preparations of cardiac muscle. However, molecular mechanisms underlying tension generation particularly concerning mutant proteins and their impact on sarcomere molecular signaling are currently controversial. Thus, there is a need for clarification as to how mutant proteins affect sarcomere molecular signaling in the etiology and progression of DCM. A main topic in this controversy is the control of the number of tension-generating myosin heads reacting with the thin filament. One line of investigation proposes that this number is determined by changes in the ratio of myosin heads in a sequestered super-relaxed state (SRX) or in a disordered relaxed state (DRX) poised for force generation upon the Ca2+ activation of the thin filament. Contrasting evidence from nanometer-micrometer-scale X-ray diffraction in intact trabeculae indicates that the SRX/DRX states may have a lesser role. Instead, the proposal is that myosin heads are in a basal OFF state in relaxation then transfer to an ON state through a mechano-sensing mechanism induced during early thin filament activation and increasing thick filament strain. Recent evidence about the modulation of these mechanisms by protein phosphorylation has also introduced a need for reconsidering the control of tension. We discuss these mechanisms that lead to different ideas related to how tension is disturbed by levels of mutant sarcomere proteins linked to the expression of gene variants in the complex landscape of DCM. Resolving the various mechanisms and incorporating them into a unified concept is crucial for gaining a comprehensive understanding of DCM. This deeper understanding is not only important for diagnosis and treatment strategies with small molecules, but also for understanding the reciprocal signaling processes that occur between cardiac myocytes and their micro-environment. By unraveling these complexities, we can pave the way for improved therapeutic interventions for managing DCM.

International review of blood donation nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

Nucleic acid amplification testing (NAT), in blood services context, is used for the detection of viral and parasite nucleic acids to reduce transfusion-transmitted infections. This project reviewed NAT for screening blood donations globally.

MATERIALS AND METHODS

A survey on NAT usage, developed by the International Society of Blood Transfusion Working Party on Transfusion-transmitted Infectious Diseases (ISBT WP-TTID), was distributed through ISBT WP-TTID members. Data were analysed using descriptive statistics.

RESULTS

Forty-three responses were received from 32 countries. Increased adoption of blood donation viral screening by NAT was observed over the past decade. NAT-positive donations were detected for all viruses tested in 2019 (proportion of donations positive by NAT were 0.0099% for human immunodeficiency virus [HIV], 0.0063% for hepatitis C virus [HCV], 0.0247% for hepatitis B virus [HBV], 0.0323% for hepatitis E virus [HEV], 0.0014% for West Nile virus [WNV] and 0.00005% for Zika virus [ZIKV]). Globally, over 3100 NAT-positive donations were identified as NAT yield or solely by NAT in 2019 and over 22,000 since the introduction of NAT, with HBV accounting for over half. NAT-positivity rate was higher in first-time donors for all viruses tested except WNV. During 2019, a small number of participants performed NAT for parasites (Trypanosoma cruzi, Babesia spp., Plasmodium spp.).

CONCLUSION

This survey captures current use of blood donation NAT globally. There has been increased NAT usage over the last decade. It is clear that NAT contributes to improving blood transfusion safety globally; however, there is a need to overcome economic barriers for regions/countries not performing NAT.

Prioritizing parotid gland surgery: A call for the implementation of the MSRSGC classification

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is developed to aid diagnosis and management of salivary gland tumors. This study evaluates the time-to-treatment initiation (TTI) for parotid gland tumors in the Netherlands and relates these to the MSRSGC classification. Subsequently, the use of the MSRSGC in the Netherlands is evaluated.

METHODS

Data regarding fine-needle aspiration cytology (FNAC) and histopathological resections of the parotid were gathered from the Dutch nationwide pathology data bank (PALGA). The TTI was calculated for each MSRSGC category and type of treating center. FNACs performed from 2018 to 2021 were gathered from PALGA to estimate how frequently the MSRSGC classification was applied.

RESULTS

Median TTI in days were 86 for nondiagnostic (MSRSGC I), 75 for nonneoplastic (MSRSGC II), 65 for atypia of unknown significance (AUS) (MSRSGC III), 89 for benign (MSRSGC IVa), 52 for salivary gland neoplasm of unknown malignant potential (SUMP) (MSRSGC IVb), 31 for suspected malignant (MSRSGC V), and 30 for malignant (MSRSGC VI) categories. Significant variation in the TTI between the types of treating centers was found for the nondiagnostic, nonneoplastic, AUS, SUMP, and suspected malignant categories. In the first 3 years after the introduction of the MSRSGC, the pathologist stated the MSRSGC classification in 6.4% of all reports.

CONCLUSIONS

The median TTI for most categories is long, and there is significant interhospital variation in TTI. Preoperative risk stratification and treatment prioritization in parotid gland surgery in the Netherlands should be improved. The MSRSGC could contribute to this. Until 2021, the MSRSGS classification was implemented on a limited scale in the Netherlands.

Time Trend and Prevalence Analysis of Transfusion Transmitted Infections among Blood Donors: A Retrospective Study from 2001 to 2016

Context

Transfusion-transmitted infections (TTIs) remain a major threat to the patients receiving blood. The incidence of the transmission of various infectious agents has reduced ever since the introduction of various molecular techniques for detection.

Aims

The study tried to figure out accurate estimates of risk and trend of TTI over a period of sixteen years, essential for monitoring the safety of blood supply and evaluating the efficacy of the currently employed screening procedures.

Methods and Material

A total of 57942 blood donors' records were analyzed for the period from January 2001 to December 2016. Chi-square test (χ2) was used to evaluate the relationship between serological positivity and particular donor characteristics. A P value of less than 0.05 was considered statistically significant.

Results

Of the 57942 donations, overall prevalence of TTI was 2.7%. Of these, the reactivity rate of hepatitis B (HBV), hepatitis C, HIV, syphilis, and malaria was 1.8%, 0.42%, 0.2%, 0.31%, and 0.017%, respectively with significant P value (P < 0.05, CI: 95%). Overall prevalence was higher in replacement donors as compared to voluntary blood donors. Trend of TTI prevalence decreased from 2001 to 2016.

Conclusions

This epidemiological research on TTI is important for the region, as estimated disease burden based on comprehensive epidemiological research provides the foundation for public policy to ensure an easily accessible and adequate supply of safe and quality blood and blood components to the needy patients.

Impact of delay in diagnosis and treatment-initiation on disease stage and survival in oral cavity cancer: a systematic review

AIM/OBJECTIVES

This study aimed to systematically review the literature on the impact of delay in diagnosis and treatment of oral cavity cancer.

METHODS

PubMed and Embase were systematically searched for articles reporting impact of delay in diagnosis and treatment on cancer-stage and survival of oral cavity cancer. Studies comprising at least ten patients, and published since the year 2000, were included.

RESULTS

Sixteen studies (n = 45,001, range: 62-18,677 per study, 83% men), from Australia, Asia, Europe, North America and South America, met the inclusion criteria. Eleven studies (n = 1,460) examined delay in diagnosis, while five studies (n = 43,541) reported delay in treatment. Eight of the eleven studies, examining delay in diagnosis (n = 1,220), analyzed the correlation between delay in diagnosis and tumor stage at diagnosis. Three studies found a significant correlation between patient delay and advanced stage at diagnosis (p < 0.05), whereas three other studies did not. The studies reporting a significant correlation were from Asian countries, whereas the three studies that did not find a correlation were from other continents. Studies reporting on professional delay and total diagnostic delay, generally, did not find a significant correlation with advanced cancer at diagnosis. Time to treatment (TTI), defined as time from diagnosis to treatment, was found significantly correlated with survival in three studies (p < 0.01, p < 0.001, p < 0.05), and nonsignificant in two studies.

CONCLUSION

A significant correlation between patient delay and advanced stage cancer was reported in Asian studies only, while professional delay and total diagnostic delay were generally found to be non-correlated with advanced stage cancer at diagnosis. TTI was in some studies reported to be correlated with poorer outcome, while other studies did not report a correlation. One study presented that there was no clear advantage in overall survival (OS) for patients treated within 30 days, compared to patients treated between 30 and 44 days.

Enzymatic Time-Temperature Indicator Prototype Developed by Immobilizing Laccase on Electrospun Fibers to Predict Lactic Acid Bacterial Growth in Milk during Storage

Laccase was immobilized on a chitosan/polyvinyl alcohol/tetraethylorthosilicate electrospun film (ceCPTL) and colored with guaiacol to obtain a laccase time-temperature indicator (TTI) prototype. The activation energy (Ea) of coloration of the prototype was 50.89-33.62 kJ/mol when 8-25 μg/cm² laccase was immobilized on ceCPTL, and that of lactic acid bacteria (LAB) growth in milk was 73.32 kJ/mol. The Ea of coloration of the TTI prototype onto which 8-10 μg/cm² laccase was immobilized was in the required range for predicting LAB growth in milk. The coloration endpoint of the TTI prototype onto which 10 μg/cm² (0.01 U) laccase was immobilized could respond to the LAB count reaching 10⁶ colony-forming units (CFU)/mL in milk during a static temperature response test, and the prediction error was discovered to be low. In dynamic temperature response experiments with intermittent temperature changes between 4 and 25 °C, the coloration rate of the laccase TTI prototype was consistent with LAB growth. The results of this study indicate that the laccase TTI prototype can be applied as a visual monitoring indicator to assist in evaluating milk quality in cold chains.

Preliminary Study on Biosensor-Type Time-Temperature Integrator for Intelligent Food Packaging

A glucose biosensor was utilized as a platform for the time-temperature integrator (TTI), a device for intelligent food packaging. The TTI system is composed of glucose oxidase, glucose, a pH indicator, and a three-electrode potentiostat, which produces an electrical signal as well as color development. The reaction kinetics of these response variables were analyzed under isothermal conditions. The reaction rates of the electrical current and color changes were 0.0360 ± 0.0020 (95% confidence limit), 0.0566 ± 0.0026, 0.0716 ± 0.0024, 0.1073 ± 0.0028 µA/min, and 0.0187 ± 0.0005, 0.0293 ± 0.0018, 0.0363 ± 0.0012, 0.0540 ± 0.0019 1/min, at 5, 15, 25, and 35 °C, respectively. The Arrhenius activation energy of the current reaction (Ea_current) was 25.0 ± 1.6 kJ/mol and the Ea_color of the color reactions was 24.2 ± 0.6 kJ/mol. The similarity of these Ea shows agreement in the prediction of food qualities between the electrical signal and color development. Consequently, the function of the new time-temperature integrator system could be extended to that of a biosensor compatible with any electrical utilization equipment.

Seroprevalence of transfusion-transmissible infections (HBV, HCV, syphilis and HIV) among prospective blood donors in a tertiary health care facility in Calabar, Nigeria; an eleven years evaluation

Background

Provision of constant and safe blood has been a public health challenge in Sub-Saharan Africa with high prevalence of transfusion-transmissible infections (TTIs). This study was aimed at determining the trend and seroprevalence of HBV, HCV, syphilis and HIV across the years within study among prospective blood donors at blood bank in University of Calabar Teaching Hospital (UCTH), Calabar, Nigeria.

Methods

A retrospective analysis of blood donor data from January 2005 to December 2016 was conducted in Blood Bank/Donor Clinic of University of Calabar Teaching Hospital, Calabar, Nigeria. Sera samples were screened for hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (HCV), human immunodeficiency virus (HIV) 1 and 2 and Treponema pallidum using commercially available immunochromatic based kits.

Results

Out of the 24,979 screened prospective donors in the 2005–2016 study period, 3739 (14.96%) were infected with at least one infective agent. The overall prevalence of HBV, HCV, syphilis and HIV were 4.1, 3.6, 3.1 and 4.2%, respectively. During the period of study, the percentage of all transfusion-transmissible infections declined significantly with remarkable decline in HIV. The study showed male dominated donor pool (98.7%) with higher prevalence (4.2%) of transfusion-transmissible infections than in female donors (0.0%). Commercial donors constituted majority (62.0%) of the donors and as well had the highest prevalence of transfusion-transmissible infections. Majority (62.9%) of the donors were repeat donors.

Conclusion

HBV, HCV, syphilis and HIV have remained a big threat to safe blood transfusion in Nigeria and Sub-Saharan Africa at large. Strict adherence to selection criteria and algorithm of donor screening are recommended.

Guideline for proper usage of time temperature integrator (TTI) avoiding underestimation of food deterioration in terms of temperature dependency: A case with a microbial TTI and milk

Time-temperature integrators (TTIs) can be used to predict food deterioration. However, underestimation of the magnitude of deterioration is not desirable. This study aims to establish guidelines in terms of temperature dependency (Arrhenius activation energy, Ea) to avoid such underestimation by proper use of TTIs. A case study was executed with a microbial TTI and milk. The Ea of the TTI color change was 106 kJ/mol and those of milk deterioration factors aerobic mesophilic bacteria count, lactic acid bacteria count, ln lactic acid %, and pH were 101, 107, 122, and 145 kJ/mol, respectively. The deterioration factors with values of Ea larger than that of TTI, ln lactic acid %, LAB, and pH, were found to be underestimated as compared to their actual levels by prediction from TTI color change, leading to potential consumption of deteriorated milk.

Serological characterization of occult hepatitis B virus infection among blood donors in India

INTRODUCTION

Discovery of hepatitis B infections characterized by the presence of viral genome without detectable HBsAg (Occult Hepatitis; OBI) has initiated a considerable amount of research in this regard. Our study is a serological and molecular characterization of OBI among the donors who donated at our blood bank during the study period.

MATERIAL AND METHOD

During the study period HBsAg ELISA non reactive ID-NAT reactive donors samples were screened for presence of antibody against HBc, HBs and HBe. Molecular analysis of these NAT yield samples was undertaken for detection of the viral load and genotyping.

RESULT

We studied 28,134 HBsAg ELISA non reactive donor samples. On testing them with ID-NAT, HBV DNA was detected in 25 samples. Eighteen samples out of these 25 NAT yield were further worked up. The 66.6% of the NAT yield samples (12 out of 18) were reactive for antibody against HBc. The 25% (3 out of 12) of these NAT yield samples having antibody against core antigen also had antibody against HBs. The 27.7% (5 out of 18) of NAT yield detected by ID-NAT did not have any detectable serological marker in blood. Four out of 12 core antibody positive NAT yield samples had genotype A HBV infection.

CONCLUSION

As per our study molecular detection of HBV DNA by ID-NAT, we were able to analyze 18 HBV NAT yield cases among 28,134 HBsAg ELISA non reactive donors. Out of 18, 12 donors were OBI whereas the rest (6) were in window period (WP yield) of HBV infection. One out of every 3.6 NAT yield detected by ID-NAT was non reactive for all serological markers.

Nucleic acid testing for blood banks: an experience from a tertiary care centre in New Delhi, India

INTRODUCTION

Blood safety is a challenging task in India; with a population of around 1.23 billion and a high prevalence rate of HIV (0.29%), HBV (2-8%) and HCV (≈ 2%) in general population. Nucleic acid testing (NAT) in blood donor screening has been implemented in many developed countries to reduce the risk of transfusion-transmitted viral infections (TTIs). NAT shortens this window period, thereby offering blood centers a much higher sensitivity for detecting viral infections.

MATERIALS AND METHODS

Routine ID-NAT for HIV-1, HCV and HBV was started from June 2010 at AIIMS blood bank by the Procleix® Ultrio® Assay (Novartis Diagnostics, USA) a multiplex NAT, which allows the simultaneous detection of HIV-1, HCV, and HBV in a single tube. During the period of 27 months from June 2010 to August 2012, around 73,898 samples were tested for all the three viruses using both ELISA (by Genscreen Ultra HIV Ag-Ab(BIO-RAD), Hepanostika HCV Ultra & HBsAg Ultra(Biomerieux) and Nucleic acid testing. The comparative results of both the assays are being presented here in this study.

RESULTS

Out of 73,898 samples, 1104 samples (1.49%) were reactive by NAT. out of these 1104 samples, 73 were reactive for HIV-1 (0.09%), 186 were reactive for HCV only (0.25%), 779 (1.05%) were reactive for HBV only, and around 66 (0.08%) were HBV-HCV co-infections. There was one HIV, 37 HCV, 73 HBV and 10 HBV-HCV co-infection cases that were not detected by serology but reactive on NAT testing, with a combined yield of 1 in 610 donations (total 121 NAT yields).

CONCLUSION

NAT could detect HIV, HBV and HCV cases in blood donor samples that were undetected by serological tests. NAT can interdict a large number of infected unit transfusions and thus help in providing safe blood to the patients.