H3K27me3 at Pericentromeric Heterochromatin is a Defining Feature of the Early Mouse Blastocyst

Early mouse development is characterized by structural and epigenetic changes at the chromatin level while cells progress towards differentiation. At blastocyst stage, the segregation of the three primordial lineages is accompanied by establishment of differential patterns of DNA methylation and post-translational modifications of histones, such as H3K27me3. In this study, we have analysed the dynamics of H3K27me3 at pericentromeric heterochromatin (PCH) during development of the mouse blastocyst, in comparison with cultured embryonic cells. We show that this histone modification is first enriched at PCH in the whole embryo and evolves into a diffuse distribution in epiblast during its specification and maturation. Concomitantly, the level of transcription from major satellite decreases. Stem cells derived from blastocyst (naïve ESCs and TSCs) do not fully maintain the H3K27me3 enrichment at PCH. Moreover, the dynamic of H3K27me3 at PCH during in vitro conversion from naïve to primed pluripotent state and during ESCs derivation suggests that the mechanisms underlying the control of this histone mark at PCH are different in embryo and in vitro. We also conclude that the non-canonical presence of H3K27me3 at PCH is a defining feature of embryonic cells in the young blastocyst before epiblast segregation.

Assessment Screening of Chest Pain in Primary Setting: A Review

Chest pain can be caused by a variety of illnesses, ranging from benign and self-limiting to significant or life-threatening. Before a doctor examines more benign reasons, a workup must focus on ruling out significant pathology. The words "dull," "deep," "pressure," and "squeezing" are commonly used to describe visceral discomfort. Visceral pain generally has a diffuse distribution pattern, making it difficult for the patient to pinpoint a precise location. chest discomfort accounts for 1.5 percent of all consultations in primary care. The age group 45 to 64 years has the highest prevalence of chest pain consultations. Patients with suspected Acute coronary syndrome (ACS) should be diagnosed and treated as soon as feasible. While most patients are sent to the hospital, an electrocardiogram (ECG) is the sole examination necessary in primary care. In this review we will be looking at chest pain incident in primary care, and also we’ll be making overview to the etiology and diagnosis of the disease.

Incidence and Characterization of Concealed Cardiac Amyloidosis Among Unselected Elderly Patients Undergoing Post-mortem Examination

Background: The prevalence of cardiac amyloidosis (CA) is unknown.Aims and Methods: We sought to (a) determine the prevalence of CA in unselected patients ≥75 years undergoing autopsy, (b) characterize cardiological profiles of CA and non-CA patients by providing clinical-histological correlations, and (c) compare their cardiological profiles. After dedicated staining, the localization (interstitial or vascular) and the distribution (non-diffuse or diffuse) of amyloid deposition were analyzed. Cardiological data at last evaluation were retrospectively assessed for the presence of CA red-flags.Results: CA (50% light chains, 50% transthyretin) was found in 43% (n = 24/56) of the autopsied hearts. Atria were involved in 96% of cases. Amyloid localized both at the perivascular and interstitial levels (95.5 and 85%, respectively) with a slightly predominant non-diffuse distribution (58% of cases). Compared to the other patients, CA patients had a more frequent history of heart failure (HF) (79 vs. 47%, p = 0.014), advanced NYHA functional class (III-IV 25 vs. 6%, p = 0.047), atrial fibrillation (68 vs. 36%, p = 0.019), discrepancy between QRS voltage and left ventricular (LV) thickness (70 vs. 12%, p < 0.001), thicker LV walls (15 vs. 11 mm, p < 0.001), enlarged left atrium (49 vs. 42 mm, p = 0.019) and restrictive filling pattern (56 vs. 19%, p = 0.020). The presence of right ventricular amyloidosis seemed to identify hearts with a higher amyloid burden. Among the CA patients, >30% had ≥3 echocardiographic red-flags of disease.Conclusion: CA can be found in 43% of autopsied hearts from patients ≥75 years old, especially in patients with HF, LV hypertrophy and atrial fibrillation.

Comparison of Chest X-rays findings in COVID-19 suspected and confirmed cases at a university teaching hospital: A retrospective comparative study

Objectives: To compare Chest X-rays findings in COVID-19 suspected and confirmed patients on RT-PCR, presented at corona filtration center, Benazir Bhutto hospital Rawalpindi. Methods: In this study, Chest radiographs of 100 COVID-19 RT-PCR positive confirmed patients were compared with 100 RT-PCR negative suspected COVID-19 patients screened at corona filtration center, Benazir Bhutto Hospital Rawalpindi from November 2020 to December 2020. Data on demographics, presenting complaints, co-morbid, lesion characteristic, distribution and attenuation, lobar involvement, pleural effusion and lymphadenopathy were collected. Associations between imaging characteristics and COVID-19 pneumonia were analyzed with univariate and multivariate logistic regression modals. Results: Chest X-rays findings revealed bilateral lung consolidation with peripheral and diffuse distribution, involving middle and lower lobe to be statistically significant (p<0.05) between RT-PCR positives and negative patients. Peripheral distribution was associated with an 11.08-fold risk in COVID-19 positive patients than diffuse distribution. Middle lobe involvement had four folds risk and lower lobe involvement had 11.04 folds risk in COVID-19 cases as compared to upper lobe involvement. Consolidation had 2.6 folds risk in COVID-19 positive cases. Conclusions: Bilateral, peripheral distribution of middle and lower lobes ground glass haze or consolidation with no pleural effusion is significantly related to COVID-19 pneumonia. Overlapping imaging features of the infectious and non-infectious COVID mimickers can be further excluded by detailed clinical evaluation and further radiological workup. doi: https://doi.org/10.12669/pjms.38.1.4624 How to cite this:Durrani M, Shahid A, Kalsoom U, Inam-ul-Haq, Yousaf A, Naveed S. Comparison of Chest X-rays findings in COVID-19 suspected and confirmed cases at a university teaching hospital: A retrospective comparative study. Pak J Med Sci. 2022;38(1):---------. doi: https://doi.org/10.12669/pjms.38.1.4624 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.

FDTD simulation of electromagnetic wave propagation in magnetic randomly inhomogeneous media

An algorithm for the numerical simulation of the propagation of electromagnetic waves in randomly inhomogeneous magnetic media by the FDTD method has been developed. The formulated algorithm is suitable for analyzing the main timing characteristics, as well as identifying the features of the propagation of various types of signals in both time-independent and time-dependent layered randomly inhomogeneous media. The simulation of the propagation of the sine pulse, sine signal and square wave in time-independent magnetic randomly inhomogeneous media with a various levels of phase contrast of two types - with a “diffuse” distribution of inhomogeneities and their “close packing” is carried out. The influence of the concentration of magnetic granules and the type of their distribution on the characteristics of the transmitted and reflected signals is revealed.

FDTD simulation of electromagnetic wave propagation in magnetic randomly inhomogeneous media

An algorithm for the numerical simulation of the propagation of electromagnetic waves in randomly inhomogeneous magnetic media by the FDTD method has been developed. The formulated algorithm is suitable for analyzing the main timing characteristics, as well as identifying the features of the propagation of various types of signals in both time-independent and time-dependent layered randomly inhomogeneous media. The simulation of the propagation of the sine pulse, sine signal and square wave in time-independent magnetic randomly inhomogeneous media with a various levels of phase contrast of two types - with a “diffuse” distribution of inhomogeneities and their “close packing” is carried out. The influence of the concentration of magnetic granules and the type of their distribution on the characteristics of the transmitted and reflected signals is revealed.

FDTD simulation of electromagnetic wave propagation in magnetic randomly inhomogeneous media

An algorithm for the numerical simulation of the propagation of electromagnetic waves in randomly inhomogeneous magnetic media by the FDTD method has been developed. The formulated algorithm is suitable for analyzing the main timing characteristics, as well as identifying the features of the propagation of various types of signals in both time-independent and time-dependent layered randomly inhomogeneous media. The simulation of the propagation of the sine pulse, sine signal and square wave in time-independent magnetic randomly inhomogeneous media with a various levels of phase contrast of two types - with a “diffuse” distribution of inhomogeneities and their “close packing” is carried out. The influence of the concentration of magnetic granules and the type of their distribution on the characteristics of the transmitted and reflected signals is revealed.

Clinical, laboratory, and chest CT features of severe versus non-severe pediatric patients with COVID-19 infection among different age groups

Background This study was performed with the intention of comparing the clinical, laboratory, and chest computed tomography (CT) findings between severe and non-severe patients as well as between different age groups composed of pediatric patients with confirmed COVID-19. Method This study was carried out on a total of 53 confirmed COVID-19 pediatric patients who were hospitalized in Namazi and Ali Asghar Hospitals, Shiraz, Iran. The patients were divided into two severe (n = 27) and non-severe (n = 28) groups as well as into other three groups in terms of their age: aged less than two years, aged 3–12 years and 13–17 years. It should be noted that CT scans, laboratory, and clinical features were taken from all patients at the admission time. Abnormal chest CT in COVID-19 pneumonia was found to show one of the following findings: ground-glass opacities (GGO), bilateral involvement, peripheral and diffuse distribution. Result Fever (79.2%) and dry cough (75.5%) were the most common clinical symptoms. Severe COVID-19 patients showed lymphocytosis, while the non-severe ones did not (P = 0.03). C-reactive protein (CRP) was shown to be significantly lower in patients aged less than two years than those aged 3–12 and 13–17 years (P = 0.01). It was shown also that O2 saturation experienced a significant increase as did patients’ age (P = 0.01). Severe patients had significantly higher CT abnormalities than non-severe patients (48.0% compared to 17.9%, respectively) (P = 0.02). Conclusion Lymphocytosis and abnormal CT findings are among the factors most associated with COVID-19 severity. It was, moreover, showed that the severity of COVID-19, O2 saturation, and respiratory distress were improved as the age of confirmed COVID-19 pediatric patients increased.

Dermoscopic Predictors of Benignity and Malignancy in Equivocal Lesions Predominated by Blue Color

<b><i>Background:</i></b> Blue color in dermoscopy can be seen in a wide range of benign and malignant lesions, melanocytic or not. Some blue-colored dermoscopic criteria have been associated with specific tumors, such as blue-white veil with melanoma and homogeneous blue with blue nevi. However, when blue color occupies a large part of the lesion’s surface, the dermoscopic assessment might be particularly challenging. <b><i>Objective:</i></b> To identify dermoscopic predictors associated with benignity and malignancy in tumors characterized by a predominant dermoscopic presence of blue color. <b><i>Methods:</i></b> We retrospectively screened our institutional database for tumors exhibiting blue color in at least 50% of their surface with available histopathologic diagnosis. Lesions with blue color covering less than 50% of their extent and lesions not histopathologically assessed were excluded. The dermoscopic images were evaluated for the presence of predefined criteria, including the characteristics of the blue color, coexisting colors, and the vascular structures. <b><i>Results:</i></b> Of 91 included tumors, 53 were benign (35 blue nevi, 10 angiomas, and 8 seborrheic keratoses) and 38 malignant (12 melanomas and 26 basal cell carcinomas). Our analysis revealed 3 potent dermoscopic predictors of benignity: extension of blue color in more than 75% of the surface, diffuse distribution of blue color, and absence of vessels, posing a 2.3-fold, 5.6-fold, and 6.7-fold increased probability of benignity, respectively. In contrast, asymmetric distribution of blue color, blue clods, coexistence of gray color and linear vessels were significantly predictive of malignancy, posing a 8.9-fold, 2.8-fold, 13.5-fold, and 10.4-fold increased probability, respectively. <b><i>Conclusion:</i></b> In predominantly blue tumors, the probability of malignancy is high when blue color is seen in clods or is asymmetrically distributed and when gray color or linear vessels coexist. In contrast, a diffuse distribution of blue color, its expansion in more than 75% of the surface, and the absence of vessels are highly suggestive of a benign tumor.