Distribution of cardiac troponin I in the Japanese general population and factors influencing its concentrations.

BACKGROUND: The 99th percentile of cardiac troponin I level in the general population is accepted as the cut-off for the diagnosis of acute myocardial infarction (AMI). However, it is not clear whether the cut-offs derived in racially and geographically different populations are applicable in Japan. METHODS: Troponin I was determined using the Abbott ARCHITECT STAT high-sensitive troponin I immunoassay in 698 apparently healthy individuals who visited the Japanese Red Cross Medical Center for a health checkup. RESULTS: The 99th percentile of the hsTnI in the overall population was 22.5 (95% confidence interval (CI), 16.8-36.6) pg/mL, 17.7 (95% CI 12.0-22.8) pg/mL for females and 30.6 (95% CI 17.1-53.4) pg/mL for males. The median of the hsTnI in the overall population was 3.2 (95% CI, 3.0-3.3) pg/mL, 2.6 (95% CI 2.4-2.8) pg/mL for females and 4.0 (95% CI 3.8-4.3) pg/mL for males. The age and gender had a significant influence on these values. The troponin I level also showed significant associations with the body mass index (BMI), the gamma glutamyl transferase (GGT), lactate dehydrogenase (LDH), estimated glomerular filtration rate (eGFR), and cardiac abnormalities by electrocardiography (ECG) but not with the high-sensitive C-reactive protein (hsCRP) level. CONCLUSIONS: The 99th percentiles of the troponin I measured in the general population in Japan were comparable as the ones derived in the US, Germany, and Singapore. The troponin I level was dependent on the gender, age, BMI, and cardiac abnormalities found by ECG but not by the hsCRP level.

Quantitative fluorescence in situ hybridization for investigation of telomere length dynamics in the pituitary gland using samples from 128 autopsied patients.

In order to investigate the population dynamics of telomere status, we measured the telomere lengths of glandular cells in the adenohypophysis (AH) and pituicytes, a type of glial cell, in the neurohypophysis (NH) of 128 autopsied humans (65 men, 63 women, 0 and 102 years) using our original quantitative fluorescence in situ hybridization (Q-FISH) method. Telomeres in the AH shortened with aging in both men and women, but those of pituicytes did not. Pituicyte telomeres were significantly longer in women than in men. The data suggest that telomeres shorten with age in the AH, whereas those in pituicytes maintain a constant length throughout life. Comparison of pituicyte telomere lengths among 5 generations, <18, 18-69, 70-79, 80-89, and >90 years, revealed a tendency for telomeres to be longer in individuals in their 80 s and 90 s than in those in their 70 s. These findings lend support to the widely held notion that humans with longer telomeres may have a longer life span, and shed light on the biology of pituitary gland in terms of telomere length dynamics, as well contributing to the development of bioengineered hormone-producing cell replacement strategies and regenerative therapies.

Changes in telomere length with aging in human neurons and glial cells revealed by quantitative fluorescence in situ hybridization analysis.

AIM: The telomere is a structure present at the ends of chromosomes, and is known to shorten with aging and successive rounds of cell division. However, very little is known about telomere attrition in post-mitotic cells, such as neurons. METHODS: Using our originally developed quantitative fluorescence in situ hybridization method, we analyzed age-dependent alterations of telomere length in three types of cells in the human cerebrum: neurons and glial cells in both the gray and white matter. RESULTS: In adults, telomeres were significantly longer in neurons than in glial cells, whereas in infants, telomere lengths did not differ among the three cell types. No aging-related telomere attrition was evident in neurons. However, the telomeres of glial cells were shorter in older individuals than in younger individuals, and attrition was more rapid in the white matter than in the gray matter. CONCLUSIONS: The present results suggest that the telomeres of neurons remain stable throughout life, whereas telomeres in white matter glial cells become significantly shorter with age. Examination of adults showed no significant correlation between telomere length and age in the three cell types. Although the present study was cross-sectional, the results suggest that telomere shortening before adolescence contributes to the significant decrease of telomere length in white matter glial cells. The present findings in normal cerebral tissues will be informative for future studies of telomere stability in the diseased brain. Geriatr Gerontol Int 2018; 18: 1507-1512.

Gradual telomere shortening and increasing chromosomal instability among PanIN grades and normal ductal epithelia with and without cancer in the pancreas.

A large body of evidence supports a key role for telomere dysfunction in carcinogenesis due to the induction of chromosomal instability. To study telomere shortening in precancerous pancreatic lesions, we measured telomere lengths using quantitative fluorescence in situ hybridization in the normal pancreatic duct epithelium, pancreatic intraepithelial neoplasias (PanINs), and cancers. The materials employed included surgically resected pancreatic specimens without cancer (n = 33) and with invasive ductal carcinoma (n = 36), as well as control autopsy cases (n = 150). In comparison with normal ducts, telomere length was decreased in PanIN-1, -2 and -3 and cancer. Furthermore, telomeres were shorter in cancer than in PanIN-1 and -2. Telomere length in cancer was not associated with histological type, lesion location, or cancer stage. PanINs with or without cancer showed similar telomere lengths. The incidences of atypical mitosis and anaphase bridges, which are morphological characteristics of chromosomal instability, were negatively correlated with telomere length. The telomeres in normal duct epithelium became shorter with aging, and those in PanINs or cancers were shorter than in age-matched controls, suggesting that telomere shortening occurs even when histological changes are absent. Our data strongly suggest that telomere shortening occurs in the early stages of pancreatic carcinogenesis and progresses with precancerous development. Telomere shortening and chromosomal instability in the duct epithelium might be associated with carcinogenesis of the pancreas. Determination of telomere length in pancreatic ductal lesions may be valuable for accurate detection and risk assessment of pancreatic cancer.

Quantitative fluorescence in situ hybridization measurement of telomere length in skin with/without sun exposure or actinic keratosis.

Chromosomal and genomic instability due to telomere dysfunction is known to play an important role in carcinogenesis. To study telomere shortening in the epidermis surrounding actinic keratosis, we measured telomere lengths of basal, parabasal, and suprabasal cells in epidermis with actinic keratosis (actinic keratosis group, n = 18) and without actinic keratosis (sun-protected, n = 15, and sun-exposed, n = 13 groups) and in actinic keratosis itself as well as in dermal fibroblasts in the 3 groups, using quantitative fluorescence in situ hybridization. Among the 3 cell types, telomeres of basal cells were not always the longest, suggesting that tissue stem cells are not necessarily located among basal cells. Telomeres of basal cells in the sun-exposed group were shorter than those in the sun-protected group. Telomeres in the background of actinic keratosis and in actinic keratosis itself and those of fibroblasts in actinic keratosis were significantly shorter than those in the controls. Our findings demonstrate that sun exposure induces telomere shortening and that actinic keratosis arises from epidermis with shorter telomeres despite the absence of any histologic atypia.