Age-dependent changes in metallothionein levels in liver and kidney of the Japanese

Samples of liver, renal cortex, and medulla were obtained from 55 forensic autopsies (0- to 95-yr-old Japanese). Metallothionein (MT) was determined by the Ag-hem or Cd-hem method. Zinc (Zn), copper (Cu), and cadmium (Cd) were determined by atomic absorption spectrophotometry. The mean levels of MT were 250 μg/g in the liver, and 394 μg/g (cortex) and 191 μg/g (medulla) in the kidney. Age-dependent changes were observed in both the liver and kidney. In the liver, MT level decreased during infancy and increased thereafter with age. Similar age-dependent changes in the levels of Zn and Cu were observed. In the kidney cortex, MT level increased with age, although no correlation was found after middle age. The levels of Cd and Zn also increased with age until middle age; however, they decreased thereafter. These results suggest that age-dependent changes in renal MT levels are associated with accumulation of Cd.     

大规模区带离心纯化Vero细胞乙脑疫苗

本文报道一种适合疫苗生产的大规模纯化Ｖｅｒｏ细胞乙脑疫苗的方法。原疫苗经适当浓缩和去除ＤＮＡ处理后,用不连续蔗糖梯度（３６％和６０％）。３２６００ｇ,速率区带离心４ｈ。纯化后疫苗的效力比中国参考疫苗高出６倍以上,补体结合抗原比中国参考疫苗高４～８倍。总蛋白含量低于３０μｇ／ｍＬ,牛血清含量降至０．５μｇ／ｍＬ以下,细胞残余ＤＮＡ低于１００ｐｇ／０．５ｍＬ。用此法连续制备三批纯化疫苗,其纯度和效力均高于日本鼠脑纯化疫苗。此法对于制备其它纯化Ｖｅｒｏ细胞疫苗也具有一定的参考意义。     

Identification of the gene variations in human CD22

 CD22, a member of the immunoglobulin superfamily, is a B-cell transmembrane glycoprotein that acts as an accessory-signaling component of the B-cell antigen receptor (BCR). Recent evidence indicating the role of CD22 as a negative regulator of BCR signal transduction prompted us to test the possibility that genetic variations of human CD22 may be associated with autoimmune diseases. In this study, variation screening of the entire CD22 coding region was performed, and possible association with rheumatic diseases was tested, using the genomic DNA from 207 healthy Japanese individuals, 68 patients with systemic lupus erythematosus (SLE), and 119 patients with rheumatoid arthritis (RA). Through the variation screening, seven non-synonymous and four synonymous substitutions were identified. In addition, single base substitutions were found in two introns flanking exon-intron junctions. Among these variations, Q152E substitution within the second extracellular domain was observed with a marginally higher frequency in the patients with SLE (3/68, 4.4%) than that in healthy individuals (1/207, 0.5%) (P=0.048. SLE vs healthy individuals), although this difference was no longer significant after correction for the number of comparisons (Pc=0.62). No significant association was observed between any of the variations and RA. These findings indicate that a number of genetic variants are present in CD22, and suggest that CD22 could be considered a candidate for the susceptibility genes to autoimmune diseases. Received: 14 July 1998 / Revised: 7 September 1998     

Male dominance rank and reproductive success in an enclosed group of Japanese macaques: with special reference to post-conception mating

The mating behaviour and reproductive success of male Japanese macaques (Macaca fuscata) were studied in relation to the female sexual cycles, which were monitored from the plasma profiles of gonadotropins and ovarian hormones. Based on observations of the mating behaviour during four successive mating seasons and paternity identification by DNA fingerprinting in 35 out of 37 offspring born in the subsequent birth seasons, the correlations between (1) male dominance rank and timing of mating, and (2) male dominance rank and reproductive success were examined. The results may be summarized as follows. (1) The number of copulations with ejaculation by any male was positively correlated with the male dominance rank, but not with the identified numbers of offspring fathered by each male. (2) Males could not choose ovulatory females as mating partners: the number of copulations with ejaculation with females during ovulatory weeks was not related to the male's rank. Monopolized copulations in consortship were mostly observed between high-ranking males and non-lactating parous females after conception. (3) Paternity testing showed that the male copulating most frequently with a female was not the identified father in 11 out of 15 cases. Prediction of the fathers of offspring was difficult even from the number of copulations occurring at around the estimated time of ovulation. An adaptive explanation of these correlations is discussed.     

Comparison of thermoregulatory responses to heat between Japanese Brazilians and Japanese

1. 1. Eight male Japanese Brazilians and 11 male Japanese volunteered for this study. Each one sat on a chair for 45 min at 40°C (r.h. 50%).

2. 2. Then, they exercised using a bicycle ergometer in a semi-reclining position for 45 min at 40% of maximal oxygen uptake.

3. 3. Thermal and comfort sensation confirmed that Japanese Brazilians felt cooler and more comfortable in 40°C environment than the Japanese.

4. 4. Oxygen uptake, sweat rate and body weight loss for both groups were not significantly different.

5. 5. Forearm blood flow and heart rate for Brazilians were significantly lower than those for Japanese.

6. 6. Skin temperature at chest region for Brazilians was found to be significantly higher than that for Japanese.

7. 7. Thus the thermoregulatory responses observed in Japanese Brazilians may be largely attributed to the climate in their native places located on the Tropic of Capricorn.

8. 8. These results may indicate that environment condition is the important factor in determining the thermoregulatory responses.

Sex difference in the neurotensin-immunoreactive cell populations of the preoptic area in quail (Coturnix japonica)

The distribution of neurotensin-immunoreactive cells and fibers was analyzed by immunocytochemistry in the forebrain of male and female Japanese quail (Coturnix japonica) by using an antibody directed against the C-terminal part of the molecule. Immunoreactive perikarya were located almost exclusively in the medial preoptic area with small populations also being present in the nucleus paraventricularis and in the tuberal region. Immunoreactive fibers were observed not only throughout the preoptic area-hypothalamus, but also in the septal region, nucleus intercollicularis, substantia grisea centralis and the classical catecholaminergic areas of the mesencephalon, such as the area ventralis of Tsai and the nucleus tegmenti pedunculo-pontinus, pars compacta. The preoptic neurotensin-immunoreactive cells were exclusively located within the boundaries of the sexually dimorphic medial preoptic nucleus. They were significantly more numerous in females than in males. In females, the number of neurotensin cells varied during the ovulatory cycle: fewer cells were observed in birds that were about to lay an egg (they had a calcified egg in the oviduct) than in those that had already laid or were not going to lay on that day. These data indicate major variations in the expression of neurotensin in response to neurochemical or neuroendocrine changes associated with ovulation.     

Variation of trace metals in ancient and contemporary Japanese bones

Excavated and contemporary bones (rib cortexes) of a mature age (40-60 yr) were analyzed by atomic absorption spectrometry for the concentration of seven elements, including Ca, Cd, Cu, Fe, Mn, Ni, and Pb, with a view to historically evaluating the chemical composition of the bones. Fifty-two well-preserved specimens, obtained from western Japan, were classified into six groups according to Japanese prehistoric and historic eras (Jomon, Yayoi, Kofun, Muromachi, Edo, and Contemporary). Average concentrations of Ca were 0.20-0.33 g/g in the excavated bones and 0.17 g/g in the contemporary bones. Among the trace metals, such as Cu, Fe, Mn, and Pb, which showed remarkably elevated concentrations in the Edo era bones, Cu, Fe, and Mn were found to be strongly associated with soil contamination. Lead levels only slightly increased between the Jomon and Kofun eras, but became abruptly elevated following the Edo era. In contrast, the concentrations of Cd increased abruptly in the Yayoi era to a level with an order of magnitude higher than the Edo era, and they have recently decreased to rather low contemporary levels. This tendency becomes clearer when comparing the molar ratio of trace metals to Ca. The cause of elevated Cd concentrations in early excavated bones is discussed in relation to the mineralization of bones and the surrounding environment.