Correlation between muscle strength and muscle mass, and their association with walking speed, in community-dwelling elderly Japanese individuals

OBJECTIVES

We aimed to assess the correlation between muscle strength and muscle mass based on sex and age, and their association with walking speed, which is a health predictor for independent living, in elderly Japanese individuals.

METHODS

The participants included 318 (111 men, 207 women) community-dwelling elderly Japanese individuals aged ≥65 years. Knee extension strength was assessed as an indicator of muscle strength, and bioelectrical impedance analysis was used to measure muscle mass. The maximum walking speed of participants was recorded. All measurements were categorized based on sex and age groups as follows: young-old (age, 65-74 years) and old-old (age, ≥75 years).

RESULTS

Appendicular muscle mass and knee extension strength decreased with age in both men and women. In men, knee extension strength showed significant positive correlations with leg and appendicular muscle mass in both young-old and old-old age groups. However, in women, only the old-old age group showed significant positive correlations between knee extension strength and leg and appendicular muscle mass. Muscle strength was significantly positively correlated with maximum walking speed in all groups, whereas muscle mass was not significantly correlated with maximum walking speed in men and women.

CONCLUSIONS

Muscle strength was significantly correlated with muscle mass in both age groups in men. However, in women, the correlation between muscle strength and muscle mass differed according to age. This finding suggests that the relationship between muscle strength and muscle mass differs according to sex and age. Muscle strength showed significant correlation with walking speed in both men and women in both age groups. These findings suggest that it is necessary to recognize that muscle strength is different from muscle mass, and that an individualized approach to prevent decline of muscle strength and muscle mass is necessary for health promotion in elderly.

The current situation of voluntary vaccination and the factors influencing its coverage among children in Takatsuki, Japan: focus on Hib and pneumococcal vaccines

This study aimed to understand the current scenario of voluntary vaccination and the factors influencing its coverage among 18-month-old children of Takatsuki City, Japan. Based on 1167 parents responses, we found that voluntary vaccination coverage rates were low when compared with routine vaccination rates. The children who were not the first born of the family and who had young and poorly educated parents were less likely to receive voluntary vaccination. Japanese government-supported vaccines, such as Haemophilus influenzae type b and pneumococcal vaccine, had a higher coverage than the vaccines for which parents had to bear the entire vaccination cost. Furthermore, it was found that mass communication media and family pediatricians were effective means to disseminate voluntary vaccination-related information. We envisage that an active participation of medical professionals, easy access to vaccinations, and mass awareness programs will increase voluntary vaccination coverage in Takatsuki.

[Factors related to sarcopenia in community-dwelling elderly subjects in Japan]

OBJECTIVES

This study aimed at determining the factors associated with sarcopenia, defined as low muscle mass and strength and low physical performance, in community-dwelling elderly subjects in Japan.

METHODS

The subjects included 1,074 elderly, community-dwelling Japanese people aged 65 years or older. We measured appendicular muscle mass (AMM) by bioelectrical impedance analysis, grip strength, and usual walking speed. A low muscle mass was defined by the AMM index (AMI, weight [kg]/height [m(2)] as >2 standard deviations below the mean AMI for normal young subjects. The lowest quartile for grip strength and usual walking speed were classified as low muscle strength and low physical performance, respectively. "Sarcopenia" was characterized by a low muscle mass, combined with either a low muscle strength or low physical performance. Subjects without low muscle mass or strength and low physical performance were classified as "normal." Subjects were classified as being "intermediate" if they were neither "sarcopenic" nor "normal." Items in the questionnaire included residential status, past medical history, admission during the past year, smoking and drinking habits, leisure-time physical activity, health status, depression, masticatory ability, and dietary variety score.

RESULTS

Sarcopenia was identified in 13.7% of men and 15.5% of women. Among men, a large proportion of subjects with sarcopenia had poor masticatory ability and a low dietary variety score compared with normal or intermediate subjects. Among women, a large proportion of the subjects with sarcopenia lived alone, had poor exercise habits, considered themselves to be unhealthy, and had poor masticatory ability compared with normal or intermediate subjects. A multiple logistic regression analysis showed that age and dietary variety in men and age and masticatory ability in women were associated with sarcopenia.

CONCLUSION

The present study carried out in Japan showed that sarcopenia, assessed by muscle mass, muscle strength, and physical performance, was associated with age, dietary variety score (in men), and masticatory ability (in women).

[Clinical study of an outbreak of aseptic meningitis due to echovirus type 30 in Munakata City in 1997-1998]

From October, 1997 through July, 1998, an outbreak of aseptic meningitis due to echovirus type 30 occurred in the northern part of Kyushu area in Japan. In this outbreak, clinical and virologic observations were carried out on 157 in-patients with aseptic meningitis at our hospital. The age of the patients ranged from 1 year and 9 months to 57-year old. One hundred and twenty out of 157 cases were the children under 15 years of age, and in this age group, male/female ratio was 2:1. The largest proportion of cases occurred in the 5- to 9-year age group. The number of cases reached a peak in December, 1997, but the epidemic extended to the next summer. In 12 families, more than one person became ill (total 22 cases). Virus isolation from cerebrospinal fluid (CSF) was tried on 130 out of 157 cases. Echovirus 30 was isolated in 74 cases (58 children, 16 adults), and echovirus 18 in 9 cases from June, 1998 until the end of the study. Paired acute and convalescent sera were available from the 25 patients with negative virus isolation, and 7 out of 25 patients had a fourfold or greater rise in neutralizing antibodies. Headache, fever, vomiting, nuchal rigidity were detectable in most cases, but in this outbreak, continued severe headache was characteristic. Eye pain was experienced by 2% of the total cases. In children, gastrointestinal symptoms were noted in 12% of the cases, but were not in adult patients. The CSF cell counts ranged from 2 to 3,478 cells per cubic millimeter. Fifty-eight percent were predominantly lymphocytic, while 42% were polymorphonuclear predominant. Virus was highly isolated from the CSF when the specimens were obtained within three days after the onset of the acute illness, but in one case, virus was isolated on day 7. In a few cases, virus was isolated without pleocytosis in CSF.

[A case of systemic sclerosis with crescentic glomerulonephritis associated with perinuclear-antineutrophil cytoplasmic antibody (p-ANCA)]

A 50-year-old female with systemic sclerosis (SSc) developed rapidly progressive renal insufficiency. Laboratory findings showed rapid elevation of serum creatinine level (3.8 mg/dl) and a high titer of perinuclear-antineutrophil cytoplasmic antibody (p-ANCA) (504 EU/ml). Renal pathology revealed crescentic glomerulonephritis (CrGN) without mucoid intimal proliferation of the interlobal arteries and fibrinoid necrosis of the afferent arterioles, Immunofluorescent micrography showed focal segmental granular deposition of IgG and C 3 in the mesangium and along the capillary loop and was in agreement with pauci-immune type. Recently, a subtype of renal involvement in SSc that is associated exclusively with normotensive renal failure and recognizable by p-ANCA is suggested. On the other hand, SSc with p-ANCA-positive glomerulonephritis as this case can be considered to be overlap syndrome of SSc and microscopic polyangitis nodosa (microscopic PN) because in microscopic PN, p-ANCA is detected at the range of 50% to 80% and renal pathology reveals necrotizing glomerulonephritis. In this point, we may describe this case as a suggestive one about p-ANCA-positive glomerulonephritis.

Immunoregulation of murine plasmacytoma. II. Target selectivity of anomalous killer cells and role of immune T cells for the induction

Requirements for the induction of anomalous killer (AK) cells to syngeneic MOPC 104E-KI81 plasmacytoma, and their pattern of reaction were investigated. The AK cells are Thy-1.2 positive and were induced by cocultivation of normal BALB/c spleen cells for 5 days in vitro with mitomycin C-treated MOPC 104E-KI81 cells in RPMI 1640 medium supplemented with fetal calf serum and 2-mercaptoethanol. The pattern of reactivity was investigated by direct cytotoxicity and indirect cold target inhibition assays using a panel of target cells. The results from cold target inhibition show that anomalous killer cells react with various tumor targets in the same preferential order as the results shown in direct cytotoxicity assay, and indicates that the AK cell population may be detecting the same determinants expressed to different degrees on panels of target cells. Kinetic study showed that peak cytotoxic responses were observed on day 5 and day 4, for primary and secondary sensitizing cultures, respectively. Cytotoxicity was not generated when nude mouse spleen cells were used as responder cells, suggesting the essential role of T cells in the induction. Nylon wool-column-purified splenic T cells from mice primed in vivo with intraperitoneal injection of MMC-treated stimulator cells, but not from normal mice, were able to generate AK cells in vitro. These results indicate that generation of AK cells with NK-cell-like reactivity needs inductive factors provided by the immune reaction between sensitized T cells and stimulatory MOPC 104E-KI81 cells.

Immunoregulation of murine plasmacytoma. I. Generation of anomalous killer cells in vitro by cocultivation with MOPC 104E

Murine plasmacytoma MOPC 104E-K181 is a tissue culture cell line of MOPC 104E derived from BALB/c mice. MOPC 104E-K181 implanted subcutaneously in syngeneic normal mice regresses spontaneously after an initial growth of about 10 mm. Mice that regressed tumors or mice immunized intraperitoneally with mitomycin C-treated MOPC 104E-K181 myeloma could reject subsequent challenge of viable K181 myeloma cells. In contrast to euthymic mice, T-cell-deficient athymic nude mice developed subcutaneous tumors after challenge and died from progressive tumor growth, suggesting the critical role of T cells in tumor regression. In vitro induction of cytotoxic cells was used to define the immunologic mechanism by which the host can suppress tumor growth. Spleen cells from immune mice did not show cytolytic activity in 51Cr release cytotoxicity assay, but showed inhibitory action of tumor proliferation in vitro at an effector cell to target cell ratio of 500:1 in a [3H]thymidine incorporation assay. To determine if cytotoxicity could be induced against MOPC 104E-K181 cells, in vitro sensitizing cultures were studied. We have demonstrated that normal BALB/c spleen cells became cytotoxic against MOPC 104E-K181 cells after 5 days cultivation with mitomycin C-treated stimulator cells at an optimal responder to stimulator cell ratio of 5:1. Treatment of anti-Thy-1.2 serum plus complement abolished cytotoxic activity of effector cells. Cytotoxic cells lysed not only MOPC 104E-K181 cells used for stimulation but also H-2k osteosarcoma cells. It was concluded that Thy-1.2-positive cytotoxic cells with nonspecific anomalous reactivity could be induced in murine plasmacytoma-stimulating cultures.

Dissemination of herpes simplex virus in nude mice after intracutaneous inoculation and effect of antibody on the course of infection

Dissemination of herpes simplex virus (HSV) in nude mice after intracutaneous inoculation in the midflank, and the effect of passively administered antibody on the course of infection were investigated. In untreated infected mice the skin lesions developed rapidly and HSV could first be recovered from the homogenate of the dorsal root ganglia on day 3 after infection, from the spinal cord on day 7 and from the brain on day 11. HSV could not be recovered from the blood, spleen or liver. In mice passively immunized with human gamma globulin, development of the skin lesions was rather slow and HSV could not be recovered from the homogenate of the dorsal root ganglia until day 16. From the results of explant culture of the ganglia, HSV was found to have reached the ganglia as early as 48 h after infection, even in mice administered human gamma globulin. The protective action of antibody seems to originate from the inhibition of virus growth not only at the inoculation site but also in the dorsal root ganglia.

Mechanism of antibody-mediated protection against herpes simplex virus infection in athymic nude mice: requirement of Fc portion of antibody

Experiments were performed to investigate the resistance of the host due to antibody-mediated mechanisms to herpes simplex virus (HSV) infection. Transfer of hyperimmune anti-HSV mouse serum inhibited the development of skin lesions and prolonged the survival of lethally HSV-infected nude mice. Relatively high concentrations of antibody were required to achieve this protection. Antisera prepared in heterologous animals were also effective, while administration of anti-cowpox virus serum or interferon provided no protection. This type of protection is therefore due to specific antibody and cannot be attributed to interferon. In order to delineate the requirement for antibody in antibody-mediated protection, human gamma globulin preparations were transferred to lethally HSV-infected nude mice. Transfer of intact human gamma globulin (GG) was effective in controlling infection. S-sulfonation of GG did not diminish the protective ability. However, purified F(ab')2 did not have any protective action even when it was administered frequently to maintain serum neutralizing antibody titer. GG was effective in C5-deficient mice lethally infected with HSV. These results indicate that in vivo antibody-mediated protection to HSV infection requires the Fc region of the intact IgG molecule and suggest that antibody-dependent cell-mediated cytotoxicity may be operative in vivo.

Phagocytosis-connected oxygen consumption by peripheral leukocytes from patients with systemic lupus erythematosus

The phagocytic activity of peripheral blood leukocytes was assayed by means of oxygen consumption in 28 patients with systemic lupus erythematosus (SLE) and 22 normal individuals. The method in which zymosan was added to a small volume of whole blood enabled us to assay quantitatively and rapidly both the phagocytosis-connected oxygen consumption and the opsonizing time. The degree of oxygen consumption by phagocytes from SLE patients was not significantly different from that in normals. Opsonizing time of zymosan by autologous serum in SLE patients did not differ from that in normals either. It should be emphasized, however, that the opsonizing time of zymosan in SLE patients was inversely correlated with serum complement level, especially C3 level (coefficient of correlation = -0.76, p less than 0.001). This raises the possibility that the phagocytosis may be delayed in SLE patients with low titers of C3.