Masae Yukawa

Distribution of trace elements in the human body determined by neutron activation analysis.

Neutron activation analysis and instrumental semiconductor gamma-ray spectrometry were used for analysis of 20 trace elements in 10 autopsied human organs and tissues (liver, kidney, cerebrum, cerebellum, heart, muscle, pancreas, spleen, lung, and aorta) from 63 Japanese persons, whose ages ranged from 15 days to 85 yr. Distributions of aluminum, bromine, magnesium, manganese, rubidium, selenium, and vanadium in human body were almost uniform. High concentrations of cadmium were found in kidney and liver samples. There was a high mercury concentration in the liver, kidney, and brain samples. Concentrations of other elements (arsenic, gold, cobalt, chromium, copper, iron, indium, antimony, selenium, titanium, and zinc) in each organ or tissue are also presented in this paper.

Relationship between copper, zinc and metallothionein in hepatocellular carcinoma and its surrounding liver parenchyma

BACKGROUND/AIM Accumulation of copper (Cu) in hepatocellular carcinoma (HCC), especially in small tumors, is greater than that in the surrounding liver parenchyma. Metallothionein (MT) is considered to be present as Cu-MT, Zn,Cu-MT or Zn-MT. The aim of this study was to determine the presence and localization of Cu-MT and Zn-MT in HCC and surrounding liver parenchyma. METHODS In 16 HCC patients, surgically resected specimens including HCC and surrounding liver parenchyma were evaluated. RESULTS The level of Cu present in small HCC (<4 cm in diameter) was significantly greater than that in the surrounding liver parenchyma (p<0.05). However, the level of Cu in large HCC (>4 cm in diameter) was similar to that in the surrounding liver parenchyma. Analysis by Sephadex G-75 gel filtration revealed that the peak fraction due to Cu was identical to that due to MT in 14 (87.5%) of 16 HCC, the peak fraction due to Cu and Zn was identical to that due to MT in 2 (12.5%) HCC, and the peak fraction due to Zn was identical to that of MT in none of 16 HCC. CONCLUSIONS Accumulation of Cu in small HCC, in which Cu was present as Cu-MT or Zn, Cu-MT, was greater than that in the surrounding liver parenchyma. Cu accumulation and the presence of MT in the liver may be related to carcinogenesis of HCC, because of the similarity of these findings in the experimental data of Long-Evans rats with a cinnamon-like coat color who develop HCC spontaneously.

Accumulation of copper in the liver and hepatic injury in chronic hepatitis C

Background and Aims : Relationships between chronic liver disease and trace metals have not been clearly understood. To examine connections between severity of hepatic fibrosis in chronic hepatitis C and copper, iron and zinc we measured the contents of these metals in liver tissue and serum in the patients.

Profile of trace element concentrations in the feto‐placental unit in relation to fetal growth

Background.  During pregnancy, trace elements are indispensable for life maintenance not only for the mother but also for the fetus. The purpose of this study was to examine whether fetal growth is associated with altered levels of trace elements in maternal blood, fetal blood, and placenta tissue.

Metal Contents in the Liver of Patients with Chronic Liver Disease Caused by Hepatitis C Virus

Background/Aims: The aim of this study was to investigate the relationship between trace metals and the prevalence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or hepatic cirrhosis caused by hepatitis C virus (HCV). Methods: We measured the contents of copper, iron, and zinc in HCC tissue (n = 112), dysplastic nodules (n = 7), and liver parenchyma in patients with (n = 112) and without (n = 12; 7 with grade F3 fibrosis, 5 with grade F4 fibrosis) HCC. Metals were quantified in thin-needle biopsy specimens using the particle-induced X-ray emission method (PIXE). Results: Copper level in liver parenchyma was higher in patients with HCC than in those without HCC (p < 0.01), while there was no such difference in hepatic iron. In patients with grade F4 fibrosis, copper content in the liver parenchyma was higher in the presence of HCC than in its absence (p < 0.05). Multiple regression analysis showed that the only factor significantly associated with the coexistence of HCC in HCV-positive patients with chronic liver disease was the copper level in the liver parenchyma. Conclusions: Hepatic copper overload may contribute to the development of HCC in HCV-positive patients with chronic hepatitis or cirrhosis.

Introduction of PIXE analysis system in NIRS

In March 1999, electrostatic accelerator, Tandetron (Model 4117MC, High Voltage Engineering Europe Co.) was installed in the Electrostatic Accelerator Building for PIXE (Particle Induced X-ray Emission) analysis. The accelerating voltage is 0.4 to 1.7MV, and the maximum beam current is 5μA at 3.4MeV. This system has three beam ports for different types of PIXE analysis: normal, micro-beam and in-air. The first beam port is used for normal PIXE. Since two types of X-ray detecting device, Si (Li) and CdZnTe detectors, are available here, elements from Na (Z=11) to U (Z=92) are detectable. Fifteen samples can semi automatically be measured at one time using a proton beam of optical beam size from 0.5 to 2.0 mm at 100 nA beam current. A quadrupole triplet magnet (Model OM2000, Oxford Micro beams, Ltd.) attached to the second beam port produces a proton micro-beam of square shape less than 1μm×1μm. Micro-beam scanning PIXE analysis is carried out with this beam at 50pA current and scanning area up to 2.0mm square. The in-air PIXE analysis is performed using the third beam port. The operation of this machine has been scheduled to start from April 2000 and is controlled by Division of Technology and Safety. Some results preliminarily obtained are also shorn.

The variation of trace element concentration in human hair: the trace element profile in human long hair by sectional analysis using neutron activation analysis

Neutron activation analysis was used to determine the distribution of trace elements in human hair. Hair samples were obtained from five infants (two to seven years of age) with hair length ranging from 15 to 40 cm. The hairs were divided into segments, each of 2.5 cm, starting from the scalp end and trace elements were analysed in each segment. Concentrations of I, Mg, Ca and Cu increased from the scalp end to the tip. Concentrations of Cl and Br decreased inversely. Different profiles of the concentrations of Hg, Se, Ca and Mn were seen in each sample. These results were discussed with reference to the indication of environmental pollution.

Elemental imaging of rat epididymis by micro-PIXE analysis

Abstract The epididymis, a male reproductive organ, which is a highly convoluted duct, plays an important role in transportation of spermatozoa, their maturation, and their storage. Although major elements, such as P, S and K, as well as trace elements, such as Mn, Cu, Zn, Se, are known to be essential for spermatogenesis, detailed distributions of the elements in the epididymis are only poorly understood. In the present study, Mn, Cu, Zn and Se levels in the epididymis were examined in male Wistar rats by inductively coupled argon plasma-mass spectrometry (ICP-MS) analysis and in situ multi-elemental distributions of epididymal sections were determined by micro-PIXE (particle induced X-ray emission) analysis. The Zn, Cu and Se concentrations in the epididymis of the young adult rats were around 30 μg/g wet weight, 2 μg/g wet weight and 1 μg/g wet weight, respectively, and their Mn were less than 0.5 μg/g wet weight. PIXE imaging of P and K exhibited that P and K were higher in the epididymal epithelium. In contrast, more S was detected in the lumen, which is composed of spermatozoa and a fluid. Elemental imagings of the trace elements were unclear compared with the major elements, but information about zinc localization in the epididymis was obtained.

Single particle irradiation system to cell (SPICE) at NIRS

Selective irradiation by an ionizing particle of a targeted cell organelle may disclose such mechanisms as signal transaction among cell organelles and cell-to-cell communication in the processes toward an endpoint observed. Bystander effect, existence of which has been clearly evidenced by application of the particle microbeam to biological experiments, suggests potential deviation from the conventional risk estimation at low particle fluence rates, such as in an environment of space radiation in International Space Station. To promote these studies we started the construction of a microbeam facility (named as SPICE) by using our HVEE Tandem accelerator (3.4 MeV proton and 5.1 MeV 4 He 2þ ). For our primary goal, ‘‘irradiation of cell organelle with a single particle with a position resolution of 2 l mi n a reasonable irradiation time’’, special features are considered. Usage of a triplet Q-magnet for focussing the beam to micrometer levels is an outstanding feature compared to facilities of other institutes. Other features are almost similar to those of other institutes. Those are precise position control of a cell dish holder, design of the cell dish, data acquisition of microscopic image of a cell organelle (cell nucleus), data processing, reliable particle detection, soft and hard wares to integrate all these related data and system to control and irradiate a targeted spot with exactly determined number of particles.

LOBE-SPECIFIC CHANGES IN ZINC LEVELS IN THE PROSTATE OF RATS EXPOSED TO TRIBUTYLTIN CHLORIDE

The prostate is an accessory sex organ that secretes essential components of semen. High levels of Zn are found both in the prostate and its secretion. In the present study, the effects of environmental stress on zinc levels in the prostate were examined in Wistar male rats exposed to tributyltin chloride (TBTC), an environmental toxicant, by inductively coupled argon plasma–mass spectrometry (ICP-MS) for determination of Zn concentration in lobe-dissectioned specimens and micro-PIXE analysis for determination of site-specific distribution of Zn in prostatic sections. A single oral administration of TBTC to rats at a dose of 90 μmol/kg resulted 14 days later in a decrease in the Zn level in the dorsolateral prostate but not the ventral prostate. The TBTC did not affect the weight of the prostate tissue. Micro-PIXE imaging found Zn both in the lumen and the epithelium of the lateral prostatic tubules. PIXE spot analysis revealed that the epithelium of the control rat contained levels of Zn 4–fold higher than in the lumen and that Zn in the epithelium decreased selectively after TBTC exposure.