Effect of Alcohol Drinking on Gene Expression of Hepatic O6-Methylguanine DNA Methyltransferase in Chronic Liver Diseases

O⁶-methylguanine DNA methyltransferase (MGMT) is a repair protein that transfers methyl groups from O⁶-methylguanine to a cysteine acceptor in its own molecule, and restores DNA to its undamaged state. If left unrepaired, O⁶-methylguanine can pair with either a thymine or a cytosine, causing a C-G to T-A transition, which is considered to be one of the molecular mechanisms of both mutagenesis and carcinogenesis. The expression of MGMT mRNA in liver tissue was quantitatively assessed by the competitive reverse transcrip-tion-polymerase chain reaction method in patients with chronic liver diseases with or without alcohol drinking. MGMT mRNA expression was 1.4 ± 0.9 pg/μg RNA in control livers. Its expression in chronic hepatitis was 3.8 ± 0.7 in alcoholics and 2.7 ± 0.8 in nonalcoholics, which were not statistically different. MGMT mRNA expression in liver cirrhosis was significantly low, compared with that in chronic hepatitis, and 0.8 ± 0.3 in alcoholics and 0.5 ± 0.1 in nonalcoholics, which also were not significantly different. The present study shows that MGMT mRNA was not decreased in patients with chronic liver diseases with alcohol drinking, compared with those without alcohol drinking.     

Effect of temporary school closure due to COVID-19 on musculoskeletal function in elementary school children

Objective: In 2020, coronavirus disease-2019 (COVID-19) became the cause of a pandemic. In response, the Japan Sports Agency issued warnings about secondary damage to health, such as the threat to physical and mental well-being due to the lack of exercise in this situation. In this study, we report on cross-sectional and longitudinal examinations of standing trunk flexion to evaluate how temporary long-term school closures affected musculoskeletal function in elementary school students.Patients and Methods: All children in one public elementary school in T-city during the school years 2019 and 2020 were included in this study. A digital forward flexion meter was used to measure standing trunk flexion.Results: In this study, 284 (284/289: 98.3%) and 266 (266/274: 97.1%) children in school years 2020 and 2019, respectively, were found to have valid data for cross-sectional analysis. The standing trunk flexion did not show significant differences between grades or sexes. In the longitudinal analysis, the results of the comparison of standing trunk flexion in children for two consecutive years revealed significant differences only between grades 3 and 4 (P<0.05) and between girls in grades 3 and 4 (P<0.01), but no significant differences in other grades or among boys or girls were observed.Conclusion: Initially, we expected that there would be a difference in the results of functional assessment using standing trunk flexion depending on the period of absence from school. However, the results of this study showed no significant changes in standing trunk flexion. Moreover, since children’s musculoskeletal functions may be affected by various factors during the COVID-19 pandemic, they should be carefully monitored in the future.     

Three-dimensional visualization of the bovine cardiac conduction system and surrounding structures compared to the arrangements in the human heart

In the human heart, the atrioventricular node is located toward the apex of the triangle of Koch, which is also at the apex of the inferior pyramidal space. It is adjacent to the atrioventricular portion of the membranous septum, through which it penetrates to become the atrioventricular bundle. Subsequent to its penetration, the conduction axis is located on the crest of the ventricular septum, sandwiched between the muscular septum and ventricular component of the membranous septum, where it gives rise to the ramifications of the left bundle branch. In contrast, the bovine conduction axis has a long non-branching component, which penetrates into a thick muscular atrioventricular septum having skirted the main cardiac bone and the rightward half of the non-coronary sinus of the aortic root. It commonly gives rise to both right and left bundle branches within the muscular ventricular septum. Unlike the situation in man, the left bundle branch is long and thin before it branches into its fascicles. These differences from the human heart, however, have yet to be shown in three-dimensions relative to the surrounding structures. We have now achieved this goal by injecting contrast material into the insulating sheaths that surround the conduction network, evaluating the results by subsequent computed tomography. The fibrous atrioventricular membranous septum of the human heart is replaced in the ox by the main cardiac bone and the muscular atrioventricular septum. The apex of the inferior pyramidal space, which in the bovine, as in the human, is related to the atrioventricular node, is placed inferiorly relative to the left ventricular outflow tract. The bovine atrioventricular conduction axis, therefore, originates from a node itself located inferiorly compared to the human arrangement. The axis must then skirt the non-coronary sinus of the aortic root prior to penetrating the thicker muscular ventricular septum, thus accounting for its long non-branching course. We envisage that our findings will further enhance comparative anatomical research.     

Chronic active hepatitis with hepatitis B virus DNA and antibody against e antigen in the serum. Disturbed synthesis and secretion of e antigen from hepatocytes due to a point mutation in the precore region

Some patients with type B chronic active hepatitis have a high titer of hepatitis B virus DNA despite antibody against e antigen in the serum. Clones of hepatitis B virus were propagated from the sera of seven patients with this disease, and the precore region was sequenced. Essentially all clones (128/131 or 98%) showed a point mutation from guanine to adenine at nucleotide 83, converting codon 28 for tryptophan (TGG) to a stop codon (TAG); the second guanine-to-adenine point mutation at nucleotide 86 was identified in only 29 clones from two patients. In patients followed up since they had hepatitis B e antigen, a shift from guanine to adenine was observed at nucleotide 83 along with the seroconversion to the antibody to e antigen. The precore-region product is required for the synthesis and secretion of e antigen from hepatocytes. A point mutation from guanine to adenine at nucleotide 83 observed in the seven patients, therefore, would be responsible for disturbed secretion of e antigen.     

Intrapulmonary bronchial blood flow of rats as studied by the microsphere method

Summary The intrapulmonary bronchial blood flow of the left lung (systemic arterial blood flow to the left lung via the bronchial artery) was determined in 45 anesthetized and artificially ventilated male Wistar rats, weighting 263±5 g (mean ± SEM). The microsphere method was employed and designed so that recirculating microspheres across the peripheral arteriovenous anastomoses were prevented from lodging in the left lung, and disturbances of the isovolemic state of the animals became minimal. Under normal conditions with a mean arteiral pressure of 115±2 mmHg (n=40), the bronchial blood flow of the left lung was found to be 0.307±0.033 ml/min on average, and amounted to 0.52±0.06% of the cardiac output. The flow (ml/min) normalized per kg body weight, 100 g wet lung, or 100 g dry lung was 1.14±0.12, 76±8, or 368±39, respectively. The total intrapulmonary bronchial blood flow of the left and right lungs could be estimated by multiplying the intrapulmonary bronchial flow of the left lung by the weight ratio (total: left) of 2.9. The variability of the flow data was small, as confirmed in a study with simultaneous injection of two differently radiolabeled microspheres. The reproducibility of duplicate measurements was excellent.     

Age-related expression analysis of mouse liver nuclear protein binding to 3′-untranslated region of <Emphasis Type="Italic">Period2</Emphasis> gene

In mammals, both circadian rhythm and aging play important roles in regulating time-dependent homeostasis. We previously discovered an age-related increase element binding protein, hnRNP A3, which binds to the 3′-untranslated region (UTR) of blood coagulation factor IX (FIX). Here, we describe other members of this protein family, hnRNP C and hnRNP H, which bind to the 3′-UTR of the mouse circadian clock gene Period 2 (mPer2). RNA electrophoretic mobility shift assays using a ³²P-labeled Per2 RNA probe coupled with two-dimensional gel electrophoresis followed by MALDI-TOF/MS peptide mass fingerprint analysis was used to analyze these proteins. Western blotting suggested that the total expression of these proteins in mouse liver cell nuclei does not increase with age. Two-dimensional gel electrophoresis analysis of age-related protein expression showed that many isoforms of these proteins exist in the liver and that each protein exhibits a complex age-related expression pattern. These results suggest that many isoforms of proteins are regulated by different aging systems and that many age regulation systems function in the liver.     

Comparison of brachial artery flow‐mediated dilation in youth with type 1 and type 2 diabetes mellitus

Aims/Introduction

Brachial artery flow‐mediated dilation (FMD) is a method of evaluating the function of vascular endothelial cells and is utilized for early diagnosis of atherosclerotic diseases. Only a few studies evaluated the risks for major vascular complications in youth with type 1 and 2 diabetes mellitus from the aspect of the early development of atherosclerosis. We studied whether there is a difference in vascular endothelial cell function between youth with type 1 and 2 diabetes mellitus.

Materials and Methods

We assessed %FMD of 24 patients with type 1 diabetes mellitus and 27 patients with type 2 diabetes mellitus aged 12–20 years along with glycated hemoglobin, lipid metabolism markers such as triglycerides, and inflammatory biomarkers such as total adiponectin levels in adolescent patients with type 1 or 2 diabetes mellitus. The significance of the difference in each factor between the type 1 and type 2 diabetes groups was assessed using Student''s t‐test.

Results

The %FMD was significantly lower in patients with type 2 diabetes. The body mass index and blood pressure were significantly higher, and total and high‐molecular‐weight adiponectin levels were significantly lower in patients with type 2 diabetes. %FMD significantly correlated with systolic blood pressure.

Conclusions

The results suggest that youth with type 2 diabetes have more advanced damage of the vascular endothelium and therefore are at higher risk for major vascular complications. Therefore, monitoring the progression of atherosclerosis would also be beneficial in youth with diabetes mellitus, and measurement of FMD could be further warranted.