Mechanical power during maximal treadmill walking and running in young and elderly men

This study determined mechanical power during movements specific to maximal walking and running using a non-motorized treadmill in 38 elderly [69.4 (5.0) years] and 50 young [24.3 (3.4) years] men. The mean mechanical power over a period of time covering six steps, during which the belt velocity peaked and then kept almost plateau, was determined as a performance score in each of maximal walking (WP) and running (RP). In terms of the value relative to body mass, the relative difference between the two age groups was greater for RP (61.7%) than for WP (21.4%) or isometric knee extension (34.1%) and flexion torque (43.8%). In the two groups, WP was significantly (P<0.05) correlated to knee extension (r=0.582 for the elderly and r=0.392 for the young) and flexion torque (r=0.524 for the elderly and r=0.574 for the young). Similarly, RP was also significantly (P<0.05) correlated to knee extension (r=0.627 for the elderly and r=0.478 for the young) and flexion torque (r=0.500 for the elderly and r=0.281 for the young). In these relationships, the WP adjusted statistically by thigh muscle torque was similar in the two age groups. However, the corresponding value for RP was significantly higher in the young than in the elderly. The findings here indicate that: (1) the difference between the young and elderly men in mechanical power is greater during maximal running than maximal walking, and (2) although the thigh muscle torque contributes to the power production during the two maximal exercise modes in the two age groups, the RP is greater in the young than in the elderly regardless of the difference in the thigh muscle torque.     

A promoter variant of the ATP-binding cassette transporter A1 gene alters the HDL cholesterol level in the general Japanese population

To investigate the effects of polymorphisms in the ATP-binding cassette transporter A1 (ABCA1) gene on the high-density lipoprotein cholesterol (HDL-C) level and the incidence of myocardial infarction (MI), we performed association studies. Sequence analysis identified 14 polymorphisms in the promoter region of ABCA1. After considering linkage disequilibrium, three polymorphisms in the promoter region and 11 polymorphisms from the JSNP database were determined in 1,880 subjects recruited from the Suita Study, representing the general population in Japan. We evaluated the association between the ABCA1 genotype and HDL-C level adjusted not only for standard factors, but also for genetic factors including ApoA1 and ApoE genotypes. Of the 14 polymorphisms tested, the G(–273)C (P=0.0074), C(–297)T (P=0.0195), and IMS-JST071749 (P=0.0093) polymorphisms were significantly associated with the HDL-C level in the Suita population. We could reconfirm that the G(–273)C genotype was influential in another set of subjects (P=0.0310, n=743). However, the distribution of the ABCA1 G(–273)C genotype in subjects with MI (n=598) was not different from that in the control population (n=801). These results indicate that ABCA1 G(–273)C has a significant effect on the HDL-C level in the general Japanese population, but not on the incidence of MI.     

GIANT CELL CARCINOMA OF THE PANCREAS

A case of giant cell carcinom of the pancreas is reported herein. The patient is a 67-year-old Japanese woman complaining of ascites, general fatigue, loss of weight, abdominal distention, nausea, and vomiting. Cytological diagnosis of ascites revealed adenocarcinoma. At autopsy, a whitish tumor measuring around 5 cm in diameter was found at the head of the pancreas. Metastasis was seen only in the liver. Histological examination displayed bizarre multinucleated giant cells occasionally phagocytosing the tumor cells and neutrophils.     

Repair of infarcted myocardium mediated by transplanted bone marrow-derived CD34+ stem cells in a nonhuman primate model

Rodent and human clinical studies have shown that transplantation of bone marrow stem cells to the ischemic myocardium results in improved cardiac function. In this study, cynomolgus monkey acute myocardial infarction was generated by ligating the left anterior descending artery, and autologous CD34(+) cells were transplanted to the peri-ischemic zone. To track the in vivo fate of transplanted cells, CD34(+) cells were genetically marked with green fluorescent protein (GFP) using a lentivirus vector before transplantation (marking efficiency, 41% on average). The group receiving cells (n = 4) demonstrated improved regional blood flow and cardiac function compared with the saline-treated group (n =4) at 2 weeks after transplant. However, very few transplanted cell-derived, GFP-positive cells were found incorporated into the vascular structure, and GFP-positive cardiomyocytes were not detected in the repaired tissue. On the other hand, cultured CD34(+) cells were found to secrete vascular endothelial growth factor (VEGF), and the in vivo regional VEGF levels showed a significant increase after the transplantation. These results suggest that the improvement is not the result of generation of transplanted cell-derived endothelial cells or cardiomyocytes; and raise the possibility that angiogenic cytokines secreted from transplanted cells potentiate angiogenic activity of endogenous cells.     

Clinical application of rapid assay of interleukin-6 in influenza-associated encephalopathy

The characteristics of influenza-associated encephalopathy is the high mortality and nimble progress with coma which appears in general cases within 48 hours. Most of patients show no abnormalities in the standard blood checks on admission or in early stage. In this study we investigated if a rapid assay of interleukin (IL)-6 is useful in influenza-associated encephalopathy in early stages. The levels of IL-6 in patients with influenza-associated encephalopathy did not show any significant difference compared with those in patients with febrile convulsion and rotavirus-associated convulsion. However the levels of IL-6 in severe cases were significantly higher than those of mild cases with influenza-associated encephalopathy. Consequently the rapid assay of serum IL-6 is useful to evaluate and decide the therapies.     

Expression of connexin 32 gap junction protein in the kidneys during fetal development of the hamster (Mesocricetus auratus)

The expression of gap junction protein was examined immunohistochemically using affinity-purified antibody against rat liver gap junction protein, connexin 32 (Cx32), in the kidneys of fetal (gestation days 13–16) and adult Syrian golden hamsters. Phalloidin histochemical staining, PNA- and RCA I-lectin stainings, NCAM immunostaining, and alkaline phosphatase and Na⁺-K⁺-ATPase enzyme-histochemical staining were performed in combination with Cx32 immunostaining. The kidney sections were observed with a confocal scanning laser microscope. By gestation day 13, Cx32 immunoreactivity was observed in the differentiating tubules. The Cx32 staining was localized on the lateral cell membrane of the cells lining the developing proximal tubules, while the S-shaped bodies, developing distal tubules, and collecting tubules showed no positive immunostaining. As the kidney developed, the density of Cx32 immunoreactivity increased. As the gap junction provides pathways for cell-cell communication, the development of Cx32 expression may imply that this structure plays an important role in renal tubule development. Confocal scanning laser microscopy provided a clear image of the fluorescence-labeled cell structures, free from out-of-focus blur. Using the same sections, stereoscopic images were easily reconstructed from serial optical sections, and were helpful in understanding the spatial distribution of Cx32 expression in the developing fetal proximal tubules.     

Biological activities of Bacteroides forsythus lipoproteins and their possible pathological roles in periodontal disease

Bacteroides forsythus is a gram-negative, anaerobic, fusiform bacterium and is considered to be an etiological agent in periodontal disease. A lipoprotein fraction prepared from B. forsythus cells by Triton X-114 phase separation (BfLP) activated human gingival fibroblasts and a human monocytic cell line, THP-1, to induce interleukin-6 production and tumor necrosis factor alpha production. BfLP was found to be capable of inducing nuclear factor-kappaB translocation in human gingival fibroblasts and THP-1 cells. By using Chinese hamster ovary K1 cells transfected with Toll-like receptor genes together with a nuclear factor-kappaB-dependent CD25 reporter plasmid, it was found that signaling by BfLP was mediated by Toll-like receptor 2 but not by CD14 or Toll-like receptor 4. BfLP induced apoptotic cell death in human gingival fibroblasts, KB cells (an oral epithelial cell line), HL-60 cells (a human myeloid leukemia cell line), and THP-1 cells but not in MOLT4 cells (a T-cell leukemia cell line). Caspase-8, an initiator caspase in apoptosis, was found to be activated in these cells in response to BfLP stimulation. Thus, this study suggested that BfLP plays some etiological roles in oral infections, especially periodontal disease, by induction of cell activation or apoptosis.