Label-free detection and characterization of heparin-induced thrombocytopenia (HIT)-like antibodies

Heparin-induced thrombocytopenia (HIT) antibodies (Abs) can mediate and activate blood cells, forming blood clots. To detect HIT Abs, immunological assays with high sensitivity (≥95%) and fast response are widely used, but only about 50% of these tests are accurate as non-HIT Abs also bind to the same antigens. We aim to develop biosensor-based electrical detection to better differentiate HIT-like from non-HIT-like Abs. As a proof of principle, we tested with two types of commercially available monoclonal Abs including KKO (inducing HIT) and RTO (noninducing HIT). Platelet factor 4/Heparin antigens were immobilized on gold electrodes, and binding of antibodies on the chips was detected based on the change in the charge transfer resistance (Rct). Binding of KKO on sensors yielded a significantly lower charge transfer resistance than that of RTO. Bound antibodies and their binding characteristics on the sensors were confirmed and characterized by complementary techniques. Analysis of thermal kinetics showed that RTO bonds are more stable than those of KKO, whereas KKO exhibited a higher negative ζ potential than RTO. These different characteristics made it possible to electrically differentiate these two types of antibodies. Our study opens a new avenue for the development of sensors for better detection of pathogenic Abs in HIT patients

The Role of Neighborhood Environment in Promoting Risk Factors of Cardiovascular Disease among Young Adults: Data from Middle to High Income Population in an Asian Megacity

Background: Modifiable risk factors of cardiovascular diseases (CVD) have their triggers in the neighborhood environments of communities. Studying the environmental triggers for CVD risk factors is important to understand the situation in a broader perspective. Young adults are influenced the most by the environment profile around them hence it is important to study this subset of the population.Methods: This was a descriptive study conducted using the EPOCH research tool designed by the authors of the PURE study. The study population consisted of young adults aged 18-25 in two areas of Karachi. The study setting was busy shopping malls frequented by young adults in the particular community being studied.Results: Our total sample size was 120 individuals, who consented to be interviewed by our interviewers. Less than 50% of the population recognized some form of restriction regarding smoking in their communities. The largest contributor to tobacco advertising was actors smoking in movies and TV shows with 89% responses from both communities. Only 11.9% of the individuals disapproved of smoking cigarettes among men with wide acceptance of \u27sheesha\u27 across all age groups. Advertising for smoking and junk food was more frequent as compared to smoking cessation, healthy diet and exercise in both the areas. Unhealthy food items were more easily available in contrast to healthier options. The cost of healthy snack food options including vegetables and fruits was higher than sugary drinks and foods.CONCLUSION: This assessment showed that both communities were exposed to environments that promote risk factors for cardiovascular diseases

High-frequency Contactless Sensor for the Detection of Heparin-Induced Thrombocytopenia Antibodies via Platelet Aggregation

Heparin-induced thrombocytopenia (HIT), a severe autoimmune disorder, occurs in patients undergoing heparin therapy. The presence of platelet-activating antibodies against platelet factor 4/Heparin in the blood confirms patients suffering from HIT. The most widely used methods for HIT diagnosis are immunoassays but the results only suit to rule out HIT as the assays provide only around 50% specificity. To confirm HIT, samples with positive results in immunoassays are retested in functional assays (>98% specificity) that track platelet-activating antibodies via platelet aggregation. However, the protocols in functional assays are either time-consuming (due to the requirement of the detection of serotonin release) or require highly trained staff for the visualization of platelets. Here, we applied a cheap and easy-to-use contactless sensor, which employs high-frequency microwaves to detect the changes in the resonant frequency caused by platelet aggregation/activation. Analysis of change in conductivity and permittivity allowed us to distinguish between HIT-like (KKO) and non-HIT-like (RTO) antibodies. KKO caused a stronger reduction of conductivity of platelet samples than RTO. Our results imply that the high-frequency contactless sensor can be a promising approach for the development of a better and easier method for the detection of HIT

Correction: A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins.

[This corrects the article DOI: 10.1371/journal.pone.0158833.]

A multitechnique approach to probe the interaction of a therapeutic tyrosine kinase inhibitor nintedanib and bovine serum albumin

<p>Drug and protein interaction provides a structural guideline in the rational drug designing and in the synthesis of new and improved drugs with greater efficacy. We have examined here the interaction tendency and mechanism of nintedanib (NTB), an anticancer drug (tyrosine kinase inhibitor) with bovine serum albumin (BSA), by spectroscopic techniques. The decline in Stern–Volmer quenching constants and binding constant with the temperature rise suggests that BSA forms a complex with NTB. Binding constant obtained by modified Stern–Volmer equation at 3 temperatures was realized to be of the order of ~10⁴ M⁻¹. Negative Δ<i>G</i> (~−5.93 kcal mol⁻¹), Δ<i>H</i> (−3.74 kcal mol⁻¹), and Δ<i>S</i> (−1.50 kcal mol⁻¹) values exhibited a spontaneous and exothermic reaction between BSA and NTB. NTB molecule interacts with BSA by forming hydrogen bonds, as elucidated by fluorescence results. Moreover, a minor increment in the helical conformation of BSA upon its binding to NTB was observed by circular dichroism spectroscopy. The modification in protein’s symmetry and a decline in hydrodynamic radii were observed in the presence of NTB (from ~3.6 to ~3 nm) as obtained by the dynamic light scattering measurement results.</p

A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins - Fig 5

<p>Absorption spectra of HSA (A) and BSA (B) gradually titrated with NDGA upto 1:10 molar ratio of albumins to NDGA, at 37°C.</p

A Multiparametric Analysis of the Synergistic Impact of Anti-Parkinson\u27s Drugs on the Fibrillation of Human Serum Albumin

Protein aggregation have been associated with several human neurodegenerative diseases, such as Parkinson\u27s and Alzheimer\u27s diseases. There are several small molecules that can reduce aggregation of proteins. The present study aimed to test the hypothesis that the application of more than one inhibitor either simultaneously or consecutively may result in more efficient inhibition of protein aggregation. To this end, the anti-amyloidogenic behaviour of benserazide hydrochloride (BH) and levodopa (LD) individually and in combination (BH + LD) was investigated using various biophysical, microscopic, and computational techniques. BH, LD, and BH + LD treatments showed inhibitory effects on protein aggregation and had the ability to minimise the amyloid-induced cytotoxicity in human neuroblastoma cell line (SH-SY5Y). The two drugs in combination showed synergism (combination index, CI \u3c 1) between them. These drugs also destabilised the preformed fibrils of human serum albumin (HSA). Our studies consistently showed that the BH + LD treatment showed highest efficacy towards inhibition and disaggregation of amyloid fibrils in comparison to treatment with BH and LD individually. Therefore, application of drugs in combination against fibrillogenesis may represent a new route for development of means for prevention or delaying of the aggregation-related diseases

Distance travelled for brain tumour surgery: A Low- and Middle-income Country Perspective

Objective: To examine the effect of distance travelled for brain tumour surgery on patient outcomes in an LMIC. Methods: Data were collected as part of the Pakistan Brain Tumour Epidemiology Study (PBTES) for brain tumour patients who underwent surgery in 2019. Mapping software was used to calculate the distance travelled by each patient from their primary address to the hospital. This was analysed in correlation with outcomes (change in KPS score, current status) and demographic variables. Results: Of 2366 patients, the median distance travelled across the country was 104 km (IQR: 9.07 - 304). Only 970 (41%) patients had access to brain tumour surgical care within 50 km of their primary address. A total of 372 (15.7%) patients requiring brain tumour surgery had to travel more than 500 km to reach their primary care hospital. Patients travelling more than 50 km for brain tumour surgery had better pre- and post-surgery Karnofsky performance scores (p<0.001) than those travelling less than 50 km. The overall survival for these patients was also better (82.4% vs 75.7%, p= 0.002) compared to patients travelling less than 50 km. Conclusion: The distance to a hospital dictates a patient's access to continuity of care through adjuvant chemoradiotherapy and regular follow-ups. Less than half of brain tumour patients in Pakistan had access to brain tumour surgery care within 50 km of their homes. Overall outcomes were significantly better in patients travelling more than 50km for neurosurgical care - suggesting a distance bias effect. Keywords: Distance travelled, Health disparities, Neuro-oncology, LMIC, Cancer epidemiology. Continue..