Biomedical subjects

Koichi Iwai

Publications and source records attributed to Koichi Iwai.

5 recordsLinked to original sources

PubMed2006

Effect of tea catechins on mitochondrial DNA 4977-bp deletions in human leucocytes.

The catechins in green tea have antioxidative and antimutagenic effects. We examined the effect of green tea enriched with catechins on the presence of mitochondrial DNA (mtDNA) with a common 4977-bp deletion mutation (mtDNA4977) in human leucocytes. Ten healthy females [aged 20.80 +/- 1.03 years] drank 350 ml of catechin-rich tea daily after supper for 5 weeks. Blood samples were collected twice before, and twice after 5 weeks of consuming the tea. Deletions in mtDNA were analyzed using the nested polymerase chain reaction (PCR). We identified a common mtDNA4977 deletion in nine participants before drinking the tea. However, this mtDNA4977 deletion was not evident in leucocytes from most of the participants 5 weeks after drinking the tea. Catechins found in tea might contribute to the maintenance of health status by reducing damage to mtDNA and by maintaining the capacity of mtDNA for oxidative phosphorylation.

Adult↗

PubMed2004

Serial changes in independent sitting in adults with severe cerebral palsy.

We investigated the natural course of independent sitting in 28 institutionalized patients with severe cerebral palsy (CP) and evaluated the factors associated with presence or absence of independent sitting during adulthood. Seventeen subjects (61%) who could not sit at the age of 10 years were never able to reach the milestone of independent sitting. Five (45%) of 11 subjects subsequently lost the ability to sit independently during the early stage of adult life. In adulthood, many of the dependent sitters had poor activities of daily living (ADL) scores and required medical care for respiration and eating/swallowing. Hip dislocation was not directly associated with the presence or absence of independent sitting. We conclude that it is important to prevent further deterioration of swallowing and respiratory functions, as well as the development of deformities or contractures from childhood and to maintain previously acquired motor function and ADL in adults with severe CP.

Activities of Daily Living↗

PubMed2003

Evaluation of hippocampal infolding using magnetic resonance imaging.

To investigate developmental morphological variation of the hippocampal formation, we evaluated the degree of hippocampal infolding in cross-sectional oblique coronal images of the cerebral peduncle and the superior cerebellar peduncle. We defined the hippocampal infolding angle as the angle between the vertical midline and the straight line connecting the medial superior margin of the subiculum with the lateral margin of the cornu ammonis. The angle increased slightly with age, and was larger in the superior cerebellar peduncle than in the cerebral peduncle and larger in the right superior cerebellar peduncle than in the left superior cerebellar peduncle. This suggests that this angle and its variation with age and location merit our attention in morphological evaluation of the hippocampal formation.

Adolescent↗

PubMed2003

[A follow-up study on mental and physical function function among stroke patients: comparisons between admission and discharge status in a rehabilitation-specialized hospital].

PURPOSE: To assess results of a 5 year-follow-up, in terms of disability, depression, quality of life, and social network in cases of stroke patients. This report deal with results at admission and discharge (in average, from 2.5 to 6 months of the onset) in a rehabilitation-specialzed hospital. OBJECT AND METHOD: The subjects were 87 stroke patients hospitalized in the Ibaraki Prefectural University Hospital. They were 64 men and 23 women, and their age were between 42 and 79 with an average of 59 years. Systematic evaluation for mental and physical functions was conducted at admission and discharge, and it is intended that the evaluation will be repeated 1, 2, 3 and 5 years from the stroke onset. RESULTS: There were substantial improvements in motor functions, general intelligence, and the status of dementia during the hospitalization. Activities of daily living and degrees of job execution and satisfactory were also improved. The prevalence of depression remained 40%, and the acceptance of limb paralysis or reduced quality of life did not change. Social network scores declined. DISCUSSION: Lack of improvement of depressive status and quality of life, and deterioration social network may increase the rist of major difficulties after discharge of stoke patients. Prevention programs at hospital may be necessary to cope with these potential problems.

Activities of Daily Living↗

PubMed2002

Dynamic changes of deleted mitochondrial DNA in human leucocytes after endurance exercise.

We examined the time course of the appearance and disappearance of deleted mitochondrial DNA (mtDNA) in human leucocytes after endurance exercise. Five untrained healthy females [aged 20.2 (0.4) years] exercised for 30 min at 50-60 W at 60 rpm on a cycle ergometer for 2 or 3 consecutive days. Blood samples were collected immediately before exercise, and on three occasions after the end of the last exercise bout. Levels of mtDNA were analyzed using the nested polymerase chain reaction method. Prior to exercise, a common mtDNA deletion was identified in all subjects. This common deletion was again identified in all subjects 1 day after completion of the exercise regime. However, mtDNA with this common deletion was found to have disappeared 2 days after exercise in three subjects, and after 4 days in the other two subjects. The deletion then reappeared 5 or 6 days after the final exercise bout in three of the five subjects. These findings demonstrate that a common deletion in leucocytes disappears over a period of several days after endurance exercise and reappears a number of days thereafter. Therefore, the status of the appearance and disappearance of common mtDNA deletion in leucocytes is highly dynamic.

Adult↗