Reviewing the definition of "elderly"

Conventionally, "elderly" has been defined as a chronological age of 65 years old or older, while those from 65 through 74 years old are referred to as "early elderly" and those over 75 years old as "late elderly." However, the evidence on which this definition is based is unknown. We have attempted to review the definition of elderly by analyzing data from long-term longitudinal epidemiological studies, and clinical and pathological studies that have been accumulated at the Tokyo Metropolitan Geriatric Hospital and the Tokyo Metropolitan Institute of Gerontology. Our recommendation might be a starting point in developing a strategy for a successful society by reviewing the definition of elderly based on comprehensive evidence in all aspects of social, cultural and medical sciences.     

Effect of the rate of speech flow on speech intelligibility in normal and hearing-impaired subjects]

The relationship between the rate of speech flow and speech intelligibility was investigated in normal and hearing-impaired subjects. It is usually observed that a slowly and clearly delivered speech is easier for hearing-impaired patients to understand. The purpose of paper is to analyze this phenomenon clinically and to present useful data for developing new hearing aids. Four or 5 syllabic words lists were prepared for this experiment and speech stimuli were chosen from these lists. The subjects consisted of 15 normal subjects and 79 hearing-impaired patients (57 with inner ear hearing loss and 22 with retrocochlear hearing loss). Hearing tests were performed using a tape recorder with various speech control systems in a soundproof room. Speech samples were presented at three speaking rates, that is, a conversational speech rate, a rate one and a half times as fast as the conversational speech rate and a rate twice as fast as that rate. The results obtained in the normal subjects confirmed that the faster the speaking rate was, the more the word intelligibility was reduced. According to the results in the hearing-impaired subjects, both the correlation coefficient and regression parameter between the word intelligibility in this experiment and speech discrimination scores measured by 57S-monosyllabic lists were low at the conversational speaking rate, but the higher the speaking rate was, the closer the relation between the both factors was. It was estimated by analyzing the data of inner ear hearing loss and retrocochler hearing loss separately that the subjects with retrocochler hearing loss had more difficulty in speech-mediated communication than the subjects with inner ear hearing loss.     

The effect of a carbon dioxide pneumoperitoneum on rabbit follicular oocytes and early embryonic development

The effect of a carbon dioxide (CO2) pneumoperitoneum and its duration on rabbit follicular oocytes was assessed by evaluating fertilization and subsequent embryonic development rates. CO2 may cross the plasma membrane and form carbonic acid, which liberates H+, thus lowering the intracellular pH. There were no significant differences in arterial pH and [HCO3-] between CO2 and air treatment groups, whereas arterial pCO2 and pO2 were significantly increased in the CO2 treatment group. We found that the duration of pneumoperitoneum, irrespective of type of gas used, was negatively correlated with success of embryonic development. These findings necessitate that more attention be given to the gas used for creation of a pneumoperitoneum during egg retrieval for in vitro fertilization and an attempt be made to minimize duration of the pneumoperitoneum.     

Clinical experience of local thermotherapy in the treatment of benign prostatic hyperplasia]

Thirty-five patients with benign prostatic hyperplasia (age range: 45-88 years; average: 67.5 years) underwent local thermotherapy with prostathermer. Clinical therapeutic effect was evaluated in 30 of the 35 patients: 2 patients interrupting from therapy and 3 receiving pretherapeutic indwelling catheters were not included. A total of 6 treatments (2 per week) were performed, each lasting for 60 minutes. As for subjective improvement, improvement of nocturia was noted in 70.0% of all patients and sense of residual urine in 70.7%. Post-therapeutic nocturnal and daytime decreases in urination frequency were statistically significant (p less than 0.01). Objective improvement in residual urine volume occurred in 19 of the 30 cases, and elevation in uroflowmetric maximal flow rate following therapy was statistically significant (p less than 0.05). Among complications ascribable to catheter insertion were urethral bleeding (3 cases), epididymitis (1 case) and pyuria (1 case). Therapeutic result based primarily on subjective symptoms and partly on objective findings was fairly good in 17 cases (about 57%), and slightly good in 25 cases (about 83%). In conclusion, this therapy seems to be useful in the treatment of benign prostatic hyperplasia.     

Evaluation of myocardial disorders in patients with dilated cardiomyopathy and left ventricular eccentric hypertrophy--by 201Tl myocardial SPECT]

201Tl myocardial SPECT was performed in cases of dilated cardiomyopathy and valvular heart disease with left ventricular eccentric hypertrophy, and the two groups were compared from the standpoint of the mechanism of onset of myocardial disorders. Significant coefficients of correlation were seen between the Tl score and LVDd (r = 0.792, r = 0.785) and Tl score and LVEF (r = -0.634, r = -0.555) in both dilated cardiomyopathy and valvular heart disease. In cases of valvular heart disease, significant correlation coefficients (r = -0.756, r = -0.720) between LVDd and r-WR (relative-washout rate), and Tl score and r-WR were observed, but no such correlation was seen in dilated cardiomyopathy. In valvular heart disease, a decrease in myocardial perfusion associated with enlargement of the left ventricle appeared, while in dilated cardiomyopathy, there was a marked decrease in LVEF in proportion to the thallium defect. Therefore, it was assumed that left ventricular wall disorders occur due to myocardial metabolic disorders and coronary microcirculation disorders.     

Divergent expression and localization of aquaporin 5, an exocrine-type water channel,in the submandibular gland of Sprague-Dawley rats

By Western blot analysis, the expression level of aquaporin (AQP) 5 in the submandibular gland (SMG) was found to be different among individual rats of the Sprague-Dawley (SD) strain. Such differences were observed for AQP5 but not for AQP1 and consequently the SD strain was divided into two groups, one expressing a high level of AQP5 and the other a low one. The difference in average intensity of expression between the two groups was more than twofold. Immunohistochemical analysis of the SMG demonstrated that the AQP5 protein was localized in the basal and apical/lateral plasma membrane of acinar cells in rats expressing the high level of AQP5. In the rat expressing the low level, however, this channel protein was localized strongly in the apical/lateral plasma membrane, but only very weakly in the basal membrane of the acinar cells. Such a diverse localization of AQP5 was confirmed by Western blotting as well. Breeding between brother and sister was repeated for two times within high expressers and low expressers to obtain the third generation progenies (F2); the AQP5 level of the SMG in the third generation (F2 rats) from high expressers was significantly higher than the F2 from low expressers. Our present study suggests the existence of genetic variation in the expression of a water channel protein, AQP5, in rats.     

Role of NMDA receptors in the increase of glucose metabolism in the rat brain induced by fluorocitrate

The effect of inhibition of glial metabolism by infusion of fluorocitrate (FC, 1 nmol/μl, 2 μl) into the right striatum of the rat brain on the glucose metabolism was studied. Significant increases in [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake (45 min) in the right cerebral cortex and striatum were observed 4 h after the infusion of FC, both as determined by the tissue dissection method and autoradiography. No significant increase in the initial uptake of [¹⁸F]FDG (1 min) was seen in the striatum. Pretreatment with dizocilpine (MK-801), an N-methyl-d-aspartate (NMDA) receptor antagonist, reduced [¹⁸F]FDG uptake in not only FC infused hemisphere but also in the contralateral hemisphere (saline-infused side). The radioactivity concentrations in plasma at 1, 5 and 45 min after the [¹⁸F]FDG injection were not altered by MK-801. This effect of MK-801 on glucose metabolism observed in the rat brain infused with FC was different from previous reports which indicated an increase in glucose metabolism in some areas of normal rat brain. In addition, the enhancement of glucose metabolism in the striatum induced by FC was almost completely abolished by pretreatment with MK-801. In the cerebral cortex, the relative ratio of radioactivity concentration in the right hemisphere to that in the left hemisphere still remained 1.37 (tissue dissection method) or 1.55 (autoradiography), which indicated that MK-801 partially blocked the effect of FC of enhancing glucose metabolism in this region. These results indicate an important role of NMDA-mediated signal transmission on the increase of glucose utilization induced by inhibition of glial metabolism.     

Association of bone mineral density with a dinucleotide repeat polymorphism at the calcitonin (CT) locus

Calcitonin (CT), a calcium-regulating hormone, lowers the calcium level in serum by inhibiting bone resorption. Because CT may play a role in the pathogenesis of osteoporosis, genetic variations in or adjacent to the CT gene may be associated with variations in bone mineral density (BMD). The present study examined the correlation between a dinucleotide (cytosine-adenine; CA) repeat polymorphism at the CT locus and BMD in 311 Japanese postmenopausal women (mean age, 64.1 years). Seven alleles were present in this population; each allele contained 10, 11, 16, 17, 18, 19, or 20 CA repeats. Thus, we designated the respective genotypes A10, A11, A16, A17, A18, A19, and A20. The A10 and A17 alleles were the predominant alleles in the population studied. Z scores (a parameter representing deviation from the age-specific weight-adjusted average BMD) were compared between individuals that possessed one or two alleles of each genotype and those that did not possess the allele. Subjects who possessed one or two A10 alleles had lower BMD Z scores than those who did not (lumbar 2–4 BMD Z score; −0.148 ± 1.23 vs 0.182 ± 1.54; P = 0.04). No significant relationships were observed between allelic status and background data or biochemical parameters. The significant association observed between BMD and genetic variations at the CT locus implies that polymorphism at this locus may be a useful marker for the genetic study of osteoporosis. Received: August 10, 2000 / Accepted: September 6, 2000     

An enzyme-linked immunosorbent assay for the measurement of human interleukin-6

An enzyme-linked immunosorbent assay has been developed to measure human interleukin-6. The assay, based on the avidin-biotin amplified two-step sandwich method, is quick (requiring 4.5 h), sensitive (detecting 9.5 pg/ml) and satisfactory in reproducibility and specificity. It shows good correspondence with the results of bioassays, and it is not affected by serum and plasma components. These results indicate that this ELISA is suitable for application to clinical samples, which is a major advantage over the widely used bioassays.