Monoclonal antibodies to rabbit alpha-2-macroglobulin and their use in a sensitive ELISA assay

alpha-2-macroglobulin (alpha-2-M), a plasma proteinase inhibitor, plays an important role in the pathogenesis of lung inflammation. The purpose of this study was to develop a sensitive ELISA assay for rabbit alpha-2-M to allow us to define the role of this protein in a rabbit model of lung inflammation/injury. Therefore, we developed hybridomas which secrete monoclonal antibodies (mAbs) against rabbit alpha-2-M. From the antibodies produced, two (5B6 and 3C5) were selected. Both of them were of the IgG1 subclass. 5B6 reacted with native alpha-2-M as well as with the "fast" form of alpha-2-M (native alpha-2-M or the "slow" form is converted to the "fast" form by reaction with a proteinase). On the other hand, 3C5 reacted only with "fast" form of alpha-2-M. With these antibodies, we developed two ELISA assays which were used to determine the concentration of alpha-2-M in the lung fluids from rabbits with lung injury.     

Benefits of oxygen on exercise performance and pulmonary hemodynamics in patients with COPD with mild hypoxemia

STUDY OBJECTIVES: To clarify the effects of oxygen on exercise performance and pulmonary hemodynamics during exercise in patients with COPD with mild hypoxemia at rest. DESIGN: Seventy-five male patients with stable COPD ("pink puffer" type), accompanied by mild hypoxemia (> 60 mm Hg) at rest and with mild (percentage of predicted FEV1 [%FEV1] > 50%, n = 16), moderate (%FEV1 > 35% to < or = 50%, n = 25), and severe (%FEV1 < or =35%, n = 34) airflow obstruction were recruited from an outpatient clinic. A 6-min walking distance (6MD) test was administered to 75 patients, and the pulmonary hemodynamics of 43 subjects were determined during exercise on a supine bicycle ergometer at 25 W and breathing compressed air and oxygen at 2 L/min. RESULTS: Supplemental oxygen resulted in a significant increase in 6MD, except for patients with mild airflow obstruction and mild desaturation. This increase in 6MD produced by oxygen was greater as the restriction of the airflow was more severe, and correlated negatively with %FEV1, but not with PaO2 at rest or exercise hypoxemia. Pulmonary artery pressure (Ppa) and pulmonary artery occlusion pressure (Pop) increased with exercise, while the rates of increase in both types of pressure were significantly higher for severe COPD than for mild COPD and moderate COPD. Oxygen inhalation significantly reduced the increases in Ppa and Pop during exercise in patients with moderate-to-severe COPD, and the effect of oxygen on the increase in Pop correlated positively with airtrapping (vital capacity - FVC). CONCLUSION: These findings suggest that supplemental oxygen benefits patients with COPD with moderate-to-severe airflow obstruction and mild hypoxemia at rest, as reflected in improvement in exercise performance and pulmonary hypertension during exercise.     

Functional disorders of the oxidative phosphorylation system in the heart mitochondria of mice with juvenile visceral steatosis

Mice with juvenile visceral steatosis (JVS) develop remarkable cardiac hypertrophy and exhibit an increased number of mitochondria in their heart. However, the biochemical characteristics and physiological functions of these mitochondria cardiac are little known. Here we show that the respiratory activities at state 3 with glutamate plus malate or succinate in the heart mitochondria of JVS mice were greatly decreased to 47% or 77%, respectively, compared with those of control mice. The contents of cytochromes a+a(3), b, and c+c(1) in the heart mitochondria of these mice were also decreased, to 51%, 45%, and 79%, respectively, of those of the control mice. Oligomycin-sensitive ATPase activitiy in these mitochondria, however, was increased to about 2 times over that of the control mice. Surprisingly, the ATP-Pi exchange activity of the heart mitochondria of JVS mice was greatly decreased, to 35% of that of control mice. On the other hand, the expression levels of 2 subunits of H(+)-ATP synthase, i.e., coupling factor 6 and alpha subunit, in heart mitochondria from control and JVS mice were almost the same. These results indicate that the coordinate regulation of mitochondrial proliferation and gene expression for components of the oxidative phosphorylation system was markedly defective in the heart of JVS mice. Our current results also suggest the presence of a novel regulatory mechanisms of ATP synthase activities in the heart.     

A comparative analysis of zoonosis and vector surveillance systems

PURPOSE: To investigate zoonosis and vector surveillance systems in major countries, conducted by quarantine, health and environment authorities, and compare the results with the current Japanese systems. METHODS: We elaborated a questionnaire for zoonosis and vector surveillance systems regarding target diseases, vectors, period and area of operation, type of surveillance (active and/or positive), and feedback mechanisms which was then mailed to ten countries having strong trade and tourism links with Japan. We visited some authorities for further discussions. RESULTS: Eight countries which responded answered that all were conducting zoonosis and vector surveillance. Target diseases included those designated by the International Health Regulations and others with a higher priority for control and prevention in the individual countries. The type of surveillance was classified as: regular monitoring of the vector population, active detection of pathogens in vectors during a specific time period of a year, and intensive pathogen characterization when problems occurred. CONCLUSIONS: The significance of zoonosis and vector surveillance was recognized through this investigation, where we found differences in target diseases, and type of operation. The results should be utilized for generation of more useful and efficient surveillance systems in Japan.     

Endothelium-dependent contraction of rat thoracic aorta induced by gallic acid

The vascular effect of a component of hydrolysable tannins, gallic acid, was examined in isolated rat thoracic aorta. Gallic acid exerted a contractile effect on the phenylephrine- or prostaglandin F(2/alpha)-precontracted endothelium-intact arteries. In endothelium-denuded arteries, the contractile response to-gallic acid was absent. Pretreatment with N(G)-nitro-L-arginine methyl ester (30 microM) abolished the gallic acid-induced contraction. Pretreatment with indomethacin (10 microM) or BQ610 (100 nM) had no observed effect. Pretreatment with gallic acid (1-10 microM) significantly attenuated the relaxation induced by acetylcholine, and that with 10 microM gallic acid also reduced the potency of sodium nitroprusside in the relaxation, without a reduction in efficacy, in endothelium-denuded arteries. These findings indicate that gallic acid induced endothelium-dependent contraction and strongly inhibited the endothelium-dependent relaxation rather than the endothelium-independent relaxation, probably through inhibition of endothelial nitric oxide (NO) production. Since NO plays an important role in vasodilative regulation and inflammatory disorders, these findings may also indicate that gallic acid interferes with the inflammatory responses.     

MEK kinase 1 mediates the antiapoptotic effect of the Bcr-Abl oncogene through NF-kappaB activation

Bcr-Abl tyrosine kinase, a chimeric oncoprotein responsible for chronic myelogenous leukemia, constitutively activates several signal transduction pathways that stimulate cell proliferation and prevent apoptosis in hematopoietic cells. The antiapoptotic function of Bcr-Abl is necessary for hematopoietic transformation, and also contributes to leukemogenesis. Herein, we show for the first time that cell transformation induced by Bcr-Abl leads to increased expression and kinase activity of MEK kinase 1 (MEKK1), which acts upstream of the c-Jun N-terminal kinase (JNK), extracellular signal regulated kinase (ERK) and NF-kappaB signaling pathways. Inhibition of MEKK1 activity using a dominant-negative MEKK1 mutant (MEKK1km) diminished the ability of Bcr-Abl to protect cells from genotoxin-induced apoptosis, but had no effect on the proliferation of Bcr-Abl-transformed cells. Expression of MEKK1km also reduced NF-kappaB activation, and inhibited antiapoptotic c-IAP1 and c-IAP2 mRNA expression in response to the genotoxin. By contrast, neither JNK nor ERK activation was affected. These results indicate that MEKK1 is a downstream target of Bcr-Abl, and that the antiapoptotic effect of Bcr-Abl in chronic myelogenous leukemia cells is mediated via the MEKK1-NF-kappaB pathway.