Medical Hypotheses

a new publicly available database of PPG and PEPG signals collected during rest, respiration, and motion for the creation and validation of signal processing algorithms for analysis and feature extraction from PPG and PEPG signals. PPG and PEPG signals are recorded from the fingertip of ring finger from left and right hand respectively are recorded together with limbs electrocardiography (ECG) to allow a reference/comparison to be found. The new database provides a benchmark for current algorithms or could assist in the development of algorithms to be tested on two different plethysmography technologies instead of only one technology.

This study present two new concepts and definitions to the medical literature. One of those is “endogenous retinoic acid theory” and the other “retinoic acid depletion syndrome”. A new classification will be provided for the immune system: “retinoic acid dependent component” and “retinoic acid non-dependent component”. If this theory is verified, all the diseases where the retinoic acid metabolism is defective and retinoic acid levels are low will be identified and new approaches will be developed fortreating such diseases. Prevention, through intrinsic mechanisms or medications, of the excretion of pre-stored retinoic acids through liver cytochrome oxidase enzymes and increasing retinoic acid levels to therapeutic levels in cases where the body’s need for retinoic acids increases, such as acute infection, high fever, extreme catabolic process and continuous antigenic impulse, is called “Endogenous Retinoic Acid Theory”. Retinoic acids also manage their own metabolisms with feedback mechanisms. Despite such compensatory mechanisms, the retinoic acid stores of the body get depleted due to overuse of the RIG-I pathway and the Type-I interferon synthesis patway, which include retinoic acid receptors, because of reasons such as high fever, severe catabolic process and oversized viral genome (SARS-CoV-2). As a result, the RIG-I path is passivated, causing excessive TNFα and cytokine discharge over the NFκB arm by shifting to TLR3, TLR7, TLR8, TLR9, MDA5 and UPS pathways in the mechanism, adaptive immune defense neutrophils, macrophages and dendritic cells. Depletion of retinoic acid stores as a result of such overuse, leading to shifting of the immune defense mechanism to the NFκB arm, where retinoic acid cannot be used and which results in cytokine release, is called ‘’retinoic acid depletion syndrom’’. COVID-19 and each of the previously defined sepsis, SIRS and ARDS are essential a retinoic acid depletion syndrome. We claim that retinoic acid metabolism is defective especially in COVID-19 (cytokine storm) most inflammatory diseases such as sepsis, SIRS and ARDS. Finding a solution to this mechanism will require a new perspective and treatment approach to such diseases.

Dataset generated for the article entitled "Hematuria at dipstick on first versus second morning voiding: a screening for patients with persistent isolated hematuria?"

The present paper is based on this data base.

STATA DATA file. You can upload data directly to STATA.

The NCBI pBlast tool was used to test the hypothesis that SARS-CoV-2 contains a calcium-dependent fusion domain(s) similar to those that were recently discovered in both Rubella and SARS-CoV-1. An Amino Acids comparison of the two relevant amino acid regions in S protein of SARS-CoV-1 representing fusion loop 1 (FL1 = Amino Acids 798- 819) and fusion loop 2 (FL2 = Amino Acids 835 -855) was conducted using the Protein Blast program from the National Center for Biotechnology Information. Specifically, Table 1 and Table 2 exhibit the data from the Protein Blast Alignment Tool data from the calcium binding fusion domains, labeled FL1 and FL2 respectively, that compare the spike proteins of COVID-19 (SARS-CoV-2) with SARS-COV and Rubella utilizing cited reference data; GenBank: QHD43416.1 (CoV-2), NCBI Reference Sequence: NP_828851.1(CoV-1), GenBank: ACN50046.1. (Rubella), GenBank: NP_828851(Human coronavirus229E) and GenBank: AD177360.1 (hemagglutinin [Influenza A virus (A/Boston/136/2009(H1N1))]). The results demonstrated a 100% and a 95% correspondence respectively between the postulated FL1 and FL2 domains in SARS-CoV-2 (COVID-19) compared to the known FL regions for SARS-CoV-1 described in 2017. Additionally, the less pathogenic Alpha coronavirus 229E (HCoV-229E) has a solitary FL2 domain and a reduced homology length compared to the SARS-CoV-2 (COVID-19) FL2. Similarly, amino acids 49 to 55 of the Rubella Virus membrane glycoprotein E2 virus also have a smaller, but significant homology with the FL2 domain. In contrast, the Influenza H1N1 hemagglutinin (HA) protein has no significant similarity to any of the CoV FL domains. The reduced homology of HCoV-229E’s single calcium-binding domain to SARS-CoV-2 suggests attenuation of HCoV-229E, which is consistent with HC0V-229E having crossed species barriers to infect humans decades or centuries ago.

original figure

The cause of pyloric stenosis of infancy

Research data

Quantitative analysis of the skin is a new, quick, and very efficient method to quantify various skin changes like performing health assessments, determine skin conditions, and evaluating how skin responds to assigned treatment course(s). The quantitative analysis allows to produce universal measures of different skin conditions that would be more accurate and non-biased. It was theoreticized that healthy skin is more structured compared to the affected skin which exhibits more alterations due to neoplastic, inflammatory, or traumatic processes. The dermatology clinic database of deidentified dermatoscopic images of the skin affected by psoriasis and adjacent clinically intact skin were used for the current analysis. All images were captured by Visioscope PC 35 camera device (Courage + Khazaka, Germany ). All images (raw data) were transferred into specially coded and developed proprietary software which enables its users to calculate entropy values for healthy and non-healthy skin. Blank paper (baseline with minimum randomness), gridded paper (interpreted as the simplified model of skin), and chaotic patterns (interpreted as the skin affected by lesions) were used as reference entropy values. The Mann-Whitney U method was used to determine the statistical significance of gathered data. The entropy values for normal unaffected skin exhibited normal distribution with mean of 2.56 with 95% confidence interval of [2.36, 2.75]. The skin affected by psoriasis exhibited normal distribution with mean of 3.30 with 95% confidence of [2.93, 3.66]. The healthy skin has a lower entropy values compared to the entropy values of skin affected by psoriasis. That is because the healthy skin appears to have more uniformed patterns in its structure, while the skin affected by psoriasis exhibits more random features due to traumatic processes and inflammation. The current technique of implying a mathematical algorithm to calculate the Maximum entropy shows promising results because physicians would be able to use universal measures to access skin conditions with minimal sources of error.