[in Japanese]

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[in Japanese]

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There are several aspects and approaches to aging research, dependeing on researchers and their situations. We attempted to elucidate the origin of aging phenomenon but not to investigate the apparent aging phenomenon itself. An important thing to be considered at first was to recognize that the most generally adopted approach to aging research, namely comparison between young and aged men or animals, will give nothing about relationship between the cause and the result of aging. So that we started aging reserch on genetic basis using the nematode, C. elegans, as experimental animals.
This paper gives the story of our investigations over the past 20 years: the planning of investigations that we made before starting actual activity, choice of experimental animal (why the nematode?), the summary of the present state of our investigation and future prospects. In brief, after meny difficulties we isolated a mutant of C. elegans, which was named as mev-1. The mutant was found to have a shorter life span than the wild type. In addition, it was hypersensitive to the oxygen atomosphere. The mutant gene was found to correspond to succinate-reductase cytochrome b.
In view of the widely accepted evidence, showing intervention of oxygen stress (present research) and perhaps of apoptosis in aging. We can safely say that aging, including natural death, is certainly the result of “life” itself. This contradictory situation might be explainable as, God did not give an eternal advantage to life.

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[in Japanese]

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Current imaging modalities, such as ultrasonic tissue characterization, have enabled accurate determination of the composition of atherosclerotic plaque of excised aortic tissue. The aim of this study is to compare integrated backscatter (IBS) echo signals of the intima-media complex of human carotid arteries between young and elderly subjects, and to evaluate the ability of ultrasonic tissue characterization. We compared the difference in ultrasonic parameters between the carotid arteries of young healthy subjects (n=27, 25±1y.o.) and elderly subjects (n=55, 75±4y.o.). Intima-media thickness (IMT) and calibrated IBS value (C-IBS: Tissue IBS-vessel lumen IBS value) were measured. The IMT values of young and elderly subjects were 0.54±0.03 and 1.08±0.07mm, respectively (p<0.01). C-IBS of elderly subjects (11.7±0.8dB) was significantly higher than that of young subjects (6.9±0.7dB). Significantly wider standard deviation of C-IBS value in each individual was observed in elderly subjects (mean±SE of individual standard deviation in C-IBS: 4.2±0.9dB) compared with that in young subjects (1.7±0.3dB). This might reflect varied composition of atherosclerotic plaques in elderly subjects. IBS analysis would become a promising method to distinguish plaque composition quantitatively and to assess the stability of plaques in clinical setting.

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We investigated post-operative management of acute complications of percutaneous endoscopic gastrostomy (PEG) which often caused respiratory infections and local skin infections.
The subjects were a total of 341 patients (male 131, female 210, and the mean age was 80.3), they were classified into six groups by method of feeding and use of antibiotics. Patients were divided into three groups based on the time that feeding was started. In Group I, enteral feeding was not started within the first five days. In Group II, sterilized enteral feeding (lactated Ringer's solution for intravenous infusion) using sterilized intravenous infusion kit started within 24 hours after the procedure, and in Group III, feeding of the usual enteral formula started within 24 hours after the procedure. And as for the using of antibiotics, they were also divided into two groups, antibiotics administered [AB (+)] and no antibiotics administered [AB (-)]. Thus, the patients were divided into six groups according to the time of starting nutrition and the use of antibiotics. The rates of incidence of acute respiratory infections and local skin infections in the six groups were compared by the chi-square test and differences in the rates of incidence of complication were also compared between two PEG methods; the Pull/Push method and the Introducer method.
The frequency of local skin infection in Group III was significantly higher than in Group I and Group II. As for the PEG methods, the frequency of local skin infection in the Pull/Push method was significantly higher than Introducer methods. Acute respiratory infections occurred significantly less in the AB (+) group than in the AB (-) group.
Postoperative administration of antibiotics would seem to be appropriate for prophylaxis of respiratory infection in elderly patients after PEG. On the other hand, local skin infections are not related to administration of antibiotics, and are highly related to the method of feeding. We concluded that nutrition of sterilized enteral feeding immediately after operation using a sterilized intravenous infusion kit and administration of antibiotics are advisable to prevent major complications in elderly patients.

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The aim of this study is to explore the factors associated with feelings of well-being in 683 community-dwelling elderly residents, aged 65 years and over using a self-administered questionnaire. The feeling of well-being was rated using a single question item constructed by The Japanese
Association for Cerebro-cardiovascular Disease control (JACD), and then subjects were divided into two groups according to answer categories: happiness and unhappiness. There was no statistically significant difference in the proportion of subjects with happiness between males and females, or among age groups. Even when interaction among multiple factors were adjusted by logistic regression analysis, a high frequency of conversation with family was statistically significantly related to happiness, and the odds ratio of it was highest among all other factors. The odds ratio of high frequency of conversation with family was higher among the elderly aged 75 and over than among those aged 65-74. These results suggest that the construction of communication between the elderly and their family through conversation could contribute to feelings of well-being in the elderly.

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We devised a new epirubicin-based combination chemotherapy (Epi-COP) regimen for the patients with elderly non-Hodgkin's lymphoma and have treated 30 patients aged 66 years and older who had measurable diseases. In Epi-COP therapy, epirubicin was used as a substitute for doxorubicin in the CHOP regimen, and some dose modifications were made for the other agents. Combined modality treatment (CMT; chemotherapy plus radiotherapy) was adopted for 9 patients with localized disease. Complete response was obtained in 21 of all the 30 patients (70%), 8 in 9 (89%) of the CMT group and 13 in 21 (62%) of the patients with chemotherapy only (chemotherapy group). The median follow up time is 350 days, ranging from 2to 77 months. The 2 year survival rate was 56% in all patients, 67% in the CMT group and 52% in the chemotherapy group. Granulocyte colony-stimulating factor (G-CSF) was administered when the leucocyte count decreased below 2, 000/μl, and 16 patients received it in the first course. The regimen could be repeated every three weeks in most cases. Although we encountered two early deaths, the overall toxicity level seemed to be acceptable. Even when we take account of the small number of patients and the short observation period, it might be concluded that Epi-COP was effective in inducing a good remission rate with moderate toxic effect in elderly patients with non-Hodgkin's lymphoma and CMT should be adopted if it is localized. A randomized comparative study with the CHOP regimen is necessary.

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This study was conducted to clarify the relationship between long-term prognosis of functional status after stroke and the magnetic resonance imaging (MRI) findings as well as complications in the course. A total of 98 patients with initial cerebral thrombosis were enrolled, and 65 patients surviving 5 years after the event, were studied in terms of cognitive function and activity of daily living (ADL). Mean age at registration (3 months after the event) was 72.0 years-old and 44 were male. MRI findings were divided into eight categories including the size and laterality of infarction, in addition to six categories as previously described. The presence of dementia was identified according to the HDS-R and the DSM-III-R scales, and the extent of dementia, assessed with the CDR scale, was divided into 3 grades: none, mild, and severe. The extent of ADL status was also graded into 3 classes: independent, partially dependent, and completely dependent. Recurrence of stroke, pneumonia, and motor disorders (hip joint fracture) were counted as complications during the course. At baseline, dementia was identified in 44, consisting of 30 mild and 14 severe dementias. During 5 years, 11 cases with mild dementia showed deterioration, and 1 case without dementia developed mild dementia. At registration, there were 46 cases with partially dependent ADL status and 22 cases completely dependent, while deterioration of ADL was seen in 17 during 5 years. Multiple regression analyses showed that diffuse PVH and pneumonia were contributory factors to the development of dementia, while dementia, pneumonia and motor disorders were risk factors for deterioration of ADL. These findings suggested that in patients with cerebral thrombosis, especially in patients with diffuse PVH, pneumonia and motor disorders should be taken care of in order to prevent functional decline.

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