Occult Hepatitis B infection (OBI) in vaccinated groups, a metanalysis

Nowadays, the presence of HBV DNA in the absence of HBsAg; occult hepatitis B infection; (OBI), is a known clinical entity along with the rapid influx of research being conducted on its clinical relevance. Biologists and clinicians alike have a recent-standing interest in this regards. OBI has been described in several clinical settings. However, the data on its prevalence among immunized and non-immunized healthy general population, in particular, among health care workers (HCWs) is ambigous. This review attemps to explore the significance of OBI in vaccinated groups as a special subject. The prevalence of OBI among general population, vaccinated children/general population and health care workers were: 157 (5.2%), 222 (6.7%) and 33 (1.8%), respectively. The prevalence of anti-HBc among OBI-positive subjects were: 64 (40.7%), 133 (82.7%) and 27 (81.8%), respectively. OBI is partly prevalent in general population and in vaccinated individuals, especially in those who born to HBsAg positive mothers. HBV serological surveys are not enough adequate and sensitive to rule out the presence of HBV DNA. For high-risk groups (subjects born to HBsAg mothers, health care workers, isolated anti-HBc, etc) sensitive molecular tests based on real time PCR should be applied for a proper diagnosis

Sympathetic skin response in chronic renal failure patients

زمینه و هدف: نوروپاتی یورومیک یکی از شایع ترین عوارض نارسایی مزمن کلیوی است که علاوه بر اختلال سیستم عصبی سمپاتیک، نوروپاتی محیطی نیز اتفاق می افتد. تست پاسخ پوستی سمپاتیکی یک تست غیر تهاجمی و ســـاده جهت بررسی فعالیت غدد عرقی اکرین پوست در اثر تحریک سمپاتیکی می باشد. هدف از این مطالعه بررسی اختلال سیستم عصبی اتونوم در بیماران مبتلا به نارسایی کلیوی به وسیله تست SSR و مقایسه نتایج آن با علائم بالینی اتونومیک بود. مواد و روشها: در این مطالعه تست پاسخ پوستی سمپاتیکی بر روی 35 فرد سالم و 31 فرد بیمار مبتلا به نارسایـی مزمـن کلیـــوی که همودیالیزمنظم می شدند انجام شد. نتایج: پاسخ پوستی سمپاتیکی در12 فرد بیمار (7/38) محو ((Absent و در 23 فرد بیمار (74) غیر طبیعی بود. همبستگی خوبی بین تست پاسخ پوستی سمپاتیکی غیر طبیعی و علائم دیس اتونومیک بالینی مشاهده نشد ولی به نظر می رسد که در نارسایی مزمن کلیوی غیر طبیعی شدن پاسخ پوستی سمپاتیکی قبل از ظهور علائم بالینی دیس اتـــونومی رخ می دهـــد. سن، جنس،‌ طول مدت همودیالیز و طــــول تاریخچه نارسایی مزمن کلیوی بیمـــاران اثـــری روی پاسخ پوستـــی سمپاتیکی نداشت. ولی بــه نظر می رسد که تعــــداد دفعـــات دیالیز در هفتـــه روی پــــاسخ پوستی سمپاتیکی تأثیرگذار است. نتیجه گیری: می توان چنین نتیجه گرفت که در نارسایی مزمن کلیوی اختلال سیستم اتونومیکی محیطی شایع است و دیالیزکافی در بهبودی آن مؤثر می باشد.

Clinical Performance of RT-PCR and Chest CT Scan for Covid-19 Diagnosis; A Systematic Review

Context: Due to their availability and rapid turnaround time, the supplemental role of chest computed tomography (CT) scan and real-time polymerase chain reaction (RT-PCR) is growing for early diagnosis of patients with COVID-19. However, due to the low efficiency of viral nucleic acid detection as well as low specificity of chest CT scan for detecting COVID-19 pneumonia, both methods show incomplete clinical performance for proper COVID-19 disease diagnosis. The purpose of this review was to compare the clinical performance of two methods and to evaluate the diagnostic values of chest CT scan and RT-PCR for suspected COVID-19 patients. Evidence acquisition: We systemically searched PubMed, Cochrane, from December 2019 to the end of April 2020. Clinical research papers in goal fields that reviewed COVID-19 patients, whom chest CT scan, and PCR testing were performed together were included. Results: In total, we found 536 studies; and finally168 studies were shortlisted. Following title and abstract screening, we reached 83 studies based on the inclusion and exclusion criteria. Conducted screen by the full text covered 28 studies, which led to data extraction. By the full-text assessment of 28 included studies, we found 4486 assessed patients. Totally, 3164 patients had positive chest CT scans, and 3014 patients had positive PCR results. The finding showed that recent studies on the diagnostic performance of RT-PCR and chest CT scan have commonly been reported from China. Conclusion: The results from this review indicate that the chest CT scan should be used for symptomatic and hospitalized patients. Moreover, chest CT scan should not be used as a primary screening tool for diagnosing COVID-19. Application of RT-PCR as the first line diagnosis is still recommended

Periodic seepage face formation and water pressure distribution along a vertical boundary of an aquifer

Detailed measurements of the piezometric head from sand flume experiments of an idealised coastal aquifer forced by a simple harmonic boundary condition across a vertical boundary are presented. The measurements focus on the pore pressures very close to the interface View the MathML source and throw light on the details of the boundary condition, particularly with respect to meniscus suction and seepage face formation during the falling tide. Between the low and the mean water level, the response is consistent with meniscus suction free models in terms of both the vertical mean head and oscillation amplitude profiles and is consistent with the observation that this area of the interface was generally within the seepage face. Above the mean water level, the influence of meniscus formation is significant with the mean pressure head being less than that predicted by capillary free theory and oscillation amplitudes decaying faster than predicted by suction free models. The reduced hydraulic conductivity in this area due to partial drainage of pores on the falling tide also causes a delay in the response to the rising tide. The combined influence of seepage face formation, meniscus suction and reduced hydraulic conductivity generate higher harmonics with amplitudes of up to 26% of the local main harmonic. To model the influence of seepage face formation and meniscus suction a numerical solution of the Richards' equation was developed and evaluated against the data. The model-data comparison shows a good agreement with the behaviour high above the water table sensitive to the choice of moisture retention parameters

Association of polymorphisms in TLR3 and TLR7 genes with susceptibility to COVID-19 among Iranian population: a retrospective case-control study

Background and Objectives: Host genetic changes like single nucleotide polymorphisms (SNPs) are one of the main factors influencing susceptibility to viral infectious diseases. This study aimed to investigate the association between the host SNP of Toll-Like Receptor3 (TLR3) and Toll-Like Receptor7 (TLR7) genes involved in the immune system and susceptibility to COVID-19 in a sample of the Iranian population. Materials and Methods: This retrospective case-control study evaluated 244 hospitalized COVID-19 patients as the case group and 156 suspected COVID-19 patients with mild signs as the control group. The genomic DNA of patients was genotyped for TLR7 (rs179008 and rs179009) and TLR3 (rs3775291 and rs3775296) SNPs using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: A significant association between rs179008 SNP in the TLR7 gene and the susceptibility of COVID-19 was found between case and control groups. The AT genotype (Heterozygous) of TLR7 rs179008 A>T polymorphism showed a significant association with a 2.261-fold increased odds of COVID-19 (P=0.003; adjusted OR: 2.261; 99% CI: 1.117-4.575). In addition, a significant association between TC genotype of TLR7 rs179009 T>C polymorphism and increased odds of COVID-19 (P 0.004167). Conclusion: SNPs in TLR7 rs179008 and rs179009 genotypes are considered host genetic factors that could be influenced individual susceptibility to COVID-19. The SNPs in TLR3 (rs3775296 and rs3775291) showed no significant association with COVID-19 in Iranian population

A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs). Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings. Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran. Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p<0.001). Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions