Plasma Level’s of Neuregulin-1 in Healthy People

Aim. To determine the median levels of neuregulin-1 (NRG-1; endothelium-derived growth factor and the natural agonist of the ERBB3 and ERBB4 receptors) NRG-1 in healthy volunteers and to study the associations of NRG-1 levels with gender and age.Material and Methods. Ninety seven healthy participants were enrolled (median age of 44 [32-54], men 45 men [46.4%]). The following age groups were identified: 20-29 y.о. (n=20, men – 50.0%), 30-39 y.о. (n=21, men – 52.4%), 40-49 y.о. (n=22, men – 45.5%), 50-59 y.о. (n=22, men – 36.4%); 60-69 y.о. (n=12, men – 50.0%). Peripheral blood samples were collected at the time of enrolment, standard laboratory tests were performed, and NRG-1 levels were determined in the plasma samples by ELISA.Results. In the cohort of 97 healthy participants the median value of NRG-1 was 0.3 [0.121-2.24] ng/ml. NRG-1 levels did not differ significantly between men and women (p=0.145), indicating that NRG-1 levels are not influenced by gender. The levels of NRG-1 were similar in the different age groups: age 20-29 years=0.26 [0.17-0.37] ng/ml; age 30-39=0.24 [0.1-0.39] ng/ml; age 40-49=0.31 [0.19-1.15] ng/ml; age 50-59=0.37 [0.19-1.0] ng/ml; age 60-69=0.4 [0.13-0.81] ng/ml. Correlation analysis between NRG-1 levels and route blood measurements (haemoglobin, lipids, glucose, creatinine, and uretic acid) did not show significant associations.Conclusions. In this study, the median value of NRG-1 plasma levels were determined. The results of the study show that age and gender had no influence on NRG-1 values.

Evaluation of the role of rs2227983 polymorphism of EGFR gene in the development of allergic asthma

The objective of the study: to study rs2227983 polymorphism of EGFR gene in patients with allergic asthma and healthy individuals.Subjects and Methods. 179 patients suffering from allergic asthma were included in the study. The diagnosis and degree of severity were established in accordance with the GINA recommendations. The Control Group included apparently healthy individuals (n = 217). Patients with allergic asthma underwent standard laboratory and instrumental examinations and DNA typing.Results. A statistically significant predominance of AG genotype frequency in the group of patients with allergic asthma, including women, versus the group of healthy individuals, was established. AG rs2227983 genotype of EGFR gene was found to be significantly more common in patients with mild and moderate allergic asthma including women, than in healthy individuals, including women.Conclusion. The association of rs2227983 polymorphism of EGFR gene with allergic asthma has been established. A homozygous GG genotype may play a protective role against the disease.

Retrieval context determines whether event boundaries impair or enhance temporal order memory

Meaningful changes in context create "event boundaries", segmenting continuous experience into distinct episodes in memory. A foundational finding in this literature is that event boundaries impair memory for the temporal order of stimuli spanning a boundary compared to equally spaced stimuli within an event. This seems surprising in light of intuitions about memory in everyday life, where the order of within-event experiences (did I have coffee before the first bite of bagel?) often seems more difficult to recall than the order of events per se (did I have breakfast or do the dishes first?). Here, we aimed to resolve this discrepancy by manipulating whether stimuli carried information about their encoding context during retrieval, as they often do in everyday life (e.g., bagel-breakfast). In Experiments 1 and 2, we show that stimuli inherently associated with a unique encoding context produce a "flipped" order memory effect, whereby temporal memory was superior for cross-boundary than within-event item pairs. In Experiments 3 and 4, we added context information at retrieval to a standard laboratory event memory protocol where stimuli were encoded in the presence of arbitrary context cues (colored frames). We found that whether temporal order memory for cross-boundary stimuli was enhanced or impaired relative to within-event items depended on whether the context was present or absent during the memory test. Taken together, we demonstrate that the effect of event boundaries on temporal memory is malleable, and determined by the availability of context information at retrieval.

CREATININE AND CREATINE KINASE RATIO IN BLOOD OF DIFFERENT BODY TYPES - A NEW APPROACH.

Purpose: The inconsistencies and variations of creatine kinase level due to modifiable and non-modifiable factors were the basis of this study. The aim was to find out the relationships between creatinine and creatine kinase in the blood of somatotypes. Methods: The 122 males, aged 10 to 20 years, were classified according to their somatotypes. Somatotypes were measured by the ISAK method. By standard laboratory methods, creatinine and creatine kinase estimate. The IBM SPSS version 24 is used for calculation. One way ANOVA followed by post hoc tests was performed to compare the variables among the three groups (p<0.05). Results: Creatinine level in the blood insignificantly deferred among the three somatotypes. The significant differences (p<0.05) were found in creatine kinase level in the blood and creatinine/creatine kinase ratio among the three dominant Somatotypes. Creatine Kinase was significantly higher in Ectomorphs (212 U/L) than Endomorphs. Ectomorphs and mesomorphs have crossed normal creatine kinase levels (35 -175 U/L). The creatinine/creatine kinase ratio was found highest in endomorphs and lowest in the ectomorphs and significantly differed in three Somatotypes. Conclusion: Creatinine production remains the same, indicating production of Creatinine is independent of specific body types. A significant higher Creatine Kinase level in Ectomorphs over Endomorphs showed fat content was not associated with it. Significant differences in Creatinine / Creatine Kinase ratio among Somatotypes suggested its relevance between cellular and morphological relationships and might uses as biomarkers.

Impact of leaching on chloride ingress profiles in concrete

To investigate the effect of leaching on chloride ingress profiles in concrete and mortar, we exposed concrete and mortar specimens for 90 and 180 days to two different exposure solutions: 3% NaCl, and 3% NaCl with KOH added to limit leaching. The solutions were replaced weekly. After exposure, we determined total chloride profiles to investigate the chloride ingress, and portlandite profiles to assess the extent of leaching. The results showed that leaching during exposure greatly affects the chloride ingress profiles in mortar and concrete. We found that leaching leads to considerably higher maximum total chloride content and deeper chloride penetration into the concrete than in the specimens where leaching was limited. We recommend therefore that leaching should be taken into account in standard laboratory testing and that more mechanistic service life models should be used to take into account the impact of leaching.

Duration of respiratory sample stability at -80ºC for SARS-CoV-2 PCR

Objective: To determine the stability of respiratory samples for SARS-CoV-2 PCR at standard laboratory ultra-freezer temperatures (-80°C). Methods: Five hundred and sixty-five archived, SARS-CoV-2 PCR positive patient specimens received at the Pathology Department of the Indus Hospital & Health Network between January 2021 and June 2021 were retested in June 2021. Samples had been stored at -70°C or below throughout this duration. Sample integrity following storage was assessed as the percentage of samples with reproducible results, and as consistency of cycle threshold (Ct) values between the original testing and the repeat testing. Results: Of the 565 samples evaluated in this study, 86% gave reproducible results upon retesting. However, there was no correlation between the duration of storage and result reproducibility, though the majority (69% for PCR Target-I and 78% for PCR Target-II respectively) of non-reproducible results had Ct values above 30. Similarly, there was a consistent increase of Ct values upon storage at ultra-freezer temperatures, though the effect again was more contingent upon freezing the sample in the ultra-freezer rather than the duration of storage. Conclusion: SARS-CoV-2 positive respiratory specimens for PCR can be stored for up to six months at -70°C or below without loss of sample integrity, though there is some loss of PCR-detected viral targets as evidenced by an immediate increased in the PCR-generated Ct values. In addition, samples with initial Ct values above 30 are more likely to give non-reproducible results. doi: https://doi.org/10.12669/pjms.38.ICON-2022.5777 How to cite this:Aijaz J, Naseer F, Dojki M, Jamal S. Duration of respiratory sample stability at -80ºC for SARS-CoV-2 PCR. Pak J Med Sci. 2022;38(2):393-398. doi: https://doi.org/10.12669/pjms.38.ICON-2022.5777 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

External factors that affect the photoplethysmography waveforms

Photoplethysmography (PPG) is a simple and inexpensive technology used in many smart devices to monitor cardiovascular health. The PPG sensors use LED lights to penetrate into the bloodstream to detect the different blood volume changes in the tissue through skin contact by sensing the amount of light that hits the sensor. Typically, the data are displayed on a graph and it forms the pulse waveform. The information from the produced pulse waveform can be useful in calculating measurements that help monitor cardiovascular health, such as blood pressure. With many more people beginning to monitor their health status on their smart devices, it is extremely important that the PPG signal is accurate. Designing a simple experiment with standard laboratory equipment and commercial sensors, we wanted to find how external factors influence the results. In this study, it was found that external factors, touch force and temperature, can have a large impact on the resulting waveform, so the effects of those factors need to be considered in order for the information to become more reliable.

Effect of Some Storage Methods on the Quality of Maize Grown in the Ashanti Mampong Municipality of Ghana

This study aims at finding an acceptable storage method for three varieties of Maize grown in the Ashanti Mampong Municipality of Ghana. Survey and standard laboratory protocols were carried out to gather the necessary data for the study. The background study revealed that 18%, 13%, 24%, 15%, 12%, 8% and 10% of farmers store their maize by heaping on the floor, storing in cribs, conventional jute sack, plastic drum, clay pot, triple-layer hermetic bag and polypropylene respectively. The findings also indicated that moisture loss was reduced in the plastic drum and triple-layer hermetic bag after the four months of storage. The proximate composition of the stored produce showed that maize preserved better in the triple layer hermetic bag. It is recommended that the triple-layer hermetic bag should be extensively used in storing maize as it has the ability to reduce moisture loss, and also preserving the nutritional and market value of the produce stored in it.

SARS-CoV-2 and Variant Diagnostic Testing Approaches in the United States

Purpose of Review Given the rapid development of diagnostic approaches to test for and diagnose infection with SARS-CoV-2 and its associated variants including Omicron (B.1.1.529), many options are available to diagnose infection. Multiple established diagnostic companies are now providing testing platforms whereas initially, testing was being performed with simple PCR-based tests using standard laboratory reagents. Recent Findings Additional testing platforms continue to be developed, including those to detect specific variants, but challenges with testing, including obtaining testing reagents and other related supplies, are frequently encountered. With time, the testing supply chain has improved, and more established companies are providing materials to support these testing efforts. In the United States (U.S.), the need for rapid assay development and subsequent approval through the attainment of emergency use authorization (EUA) has superseded the traditional arduous diagnostic testing approval workflow mandated by the FDA. Through these efforts, the U.S. has been able to continue to significantly increase its testing capabilities to address this pandemic; however, challenges still remain due to the diversity of the performance characteristics of tests being utilized and newly discovered viral variants. Summary This review provides an overview of the current diagnostic testing landscape, with pertinent information related to SARS-CoV-2 virology, variants and antibody responses that are available to diagnose infection in the U.S.

Effects of temporal and spatiotemporal cues on detection of dynamic road hazards

While driving, dangerous situations can occur quickly, and giving drivers extra time to respond may make the road safer for everyone. Extensive research on attentional cueing in cognitive psychology has shown that targets are detected faster when preceded by a spatially valid cue, and slower when preceded by an invalid cue. However, it is unknown how these standard laboratory-based cueing effects may translate to dynamic, real-world situations like driving, where potential targets (i.e., hazardous events) are inherently more complex and variable. Observers in our study were required to correctly localize hazards in dynamic road scenes across three cue conditions (temporal, spatiotemporal valid and spatiotemporal invalid), and a no-cue baseline. All cues were presented at the first moment the hazardous situation began. Both types of valid cues reduced reaction time (by 58 and 60 ms, respectively, with no significant difference between them, a larger effect than in many classic studies). In addition, observers’ ability to accurately localize hazards dropped 11% in the spatiotemporal invalid condition, a result with dangerous implications on the road. This work demonstrates that, in spite of this added complexity, classic cueing effects persist—and may even be enhanced—for the detection of real-world hazards, and that valid cues have the potential to benefit drivers on the road.