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Hirofumi Chiba

Publications and source records attributed to Hirofumi Chiba.

8 recordsLinked to original sources
PubMed2005

Surfactant protein gene expressions for detection of lung carcinoma cells in peripheral blood.

BACKGROUND: Inflow of tumor cells to circulation is an essential step for metastasis of primary tumors. To know its state may contribute to therapeutic strategy. However, methodology to detect lung carcinoma cells floating in peripheral blood has not been established. Pulmonary surfactant protein (SP)-A, SP-C and Clara cells-10 kd protein (CC10) are specific to the lung and often expressed in primary lung carcinomas. We evaluated the worth of these gene expressions for the detection of carcinoma cells in peripheral blood. METHODS: The expressions in 5 ml of venous blood were tested by RT-PCR. Ninety-nine patients with non-small cell lung carcinoma (NSCLC) and 17 with small cell lung carcinoma (SCLC) were compared to 13 with secondary lung tumor, 48 with non-malignant respiratory diseases and 19 healthy volunteers. RESULTS: The mRNA expressions of SP-A and SP-C were completely specific to NSCLC when compared to SCLC and secondary lung tumors. All of the healthy volunteers and patients with non-malignant respiratory diseases showed negative for these mRNA expressions, except for one sample. The positive rate of SP-A, SP-C and CC10 mRNA in patients with NSCLC was 33.3%, 14.1%, 3.3%, respectively. The rates of SP-A and SP-C mRNA were higher than that (11.1%) in CEA mRNA. The increased positive rate of mRNA of SP-A and SP-C was significantly dependent on the clinical stage and the existence of distant metastasis. CONCLUSION: These results demonstrate that the detection of mRNA of SP-A and SP-C would give clinicians valuable information suggesting the presence of blood-floating carcinoma cells as a step toward metastasis.

Aged↗
PubMed2004

Surfactant protein A binds Mycoplasma pneumoniae with high affinity and attenuates its growth by recognition of disaturated phosphatidylglycerols.

Surfactant Protein A (SP-A) is an abundant, multifunctional lectin that resides within the bronchoalveolar compartment of the lung and plays an important role in the innate immunity of the organ. Mycoplasma pneumoniae is a human pathogen that resides in the same compartment as SP-A, and we examined the interaction between the two. Preparations of human and rat SP-A recognized the mycoplasma with high affinity in the presence of Ca(2+), exhibiting apparent K(')(d) values in the nanomolar range. Membranes prepared from the microbe also bound human and rat SP-A with similar characteristics and affinity to the intact cells. The ligand for SP-A was insensitive to proteolysis. Lipid extracts prepared from the mycoplasma, bound SP-A with high affinity when examined by ligand blot analysis. These lipid extracts were also potent competitive inhibitors (IC(50) = 0.2 nM) of human SP-A binding to mycoplasma membranes. The major lipid ligands for the protein identified by mass spectrometry are a group of disaturated phosphatidylglycerols. The addition of SP-A to cultures of M. pneumoniae markedly attenuated the growth of the organism assessed by colony formation, metabolic activity, and DNA replication. The bacteriostatic effects of SP-A were reversed by dipalmitoylphosphatidylglycerol. These findings demonstrate that human SP-A can play a direct role in antibody-independent immunity to M. pneumoniae by interacting with lipid ligands expressed on the surface of the organism and implicate SP-A in the immediate host response to the bacteria.

Animals↗
PubMed2004

Elevated serum surfactant protein A and D in a case of acute eosinophilic pneumonia.

A 29-year-old man was admitted to our hospital because of fever elevation, dry cough, malaise, skin eruption, and dyspnea with hypoxemia. His serum levels of surfactant protein (SP) -A and SP-D were markedly high, but serum KL-6 was not. He was diagnosed as acute eosinophilic pneumonia (AEP) on the basis of CT imaging, bronchoalveolar lavage findings and the clinical course. He showed good response to steroid therapy and serum levels of SP-A and SP-D returned to almost normal levels. Our experience suggested that serum SP-A and SP-D might be helpful markers for monitoring the clinical course in AEP.

Acute Disease↗
PubMed2003

[The environmental risk factors for COPD--tobacco smoke, air pollution, chemicals].

The identification of risk factors is an important step toward developing strategies for prevention and treatment of any disease. The risks of COPD are related to environmental exposures in combination with the genetic makeup of the individual. The principal environmental factor in COPD is well known--exposure to cigarette smoke--and it can be modified. However, although smoking is the best-studied COPD risk factor, it is not only one. Air pollution, occupational dusts and chemicals can also cause COPD when the exposures are sufficiently intense or prolonged. This is a summary of environmental risk factors for COPD.

Air Pollution↗
PubMed2002

Human surfactant protein D (SP-D) binds Mycoplasma pneumoniae by high affinity interactions with lipids.

Increasing evidence now identifies surfactant protein D (SP-D) as an important element of the innate immune system of the lung. In this study, we examined the interactions of rat and human SP-D with the human pathogen, Mycoplasma pneumoniae. Rat and human SP-D bound the organism with high affinity in a reaction that required Ca(2+) and was inhibited by EGTA. Membranes derived from the organism bound the proteins in a similar manner, except the rat SP-D also exhibited a significant level of Ca(2+)-independent binding. Pretreatment of membranes with proteases did not alter the Ca(2+)-dependent SP-D binding of membranes by either protein. Mannose, glucose, maltose, and inositol, at millimolar concentrations, competed for human SP-D binding to the bacterial membrane. Lipids extracted from membranes and separated by two-dimensional thin layer chromatography bound human SP-D with high affinity in a Ca(2+)-dependent reaction. A tandem mutant of SP-D with E321Q and N323D substitutions, failed to bind M. pneumoniae lipids, directly implicating the carbohydrate recognition domain in the interaction. The interaction of rat and human SP-D with M. pneumoniae was unaffected by the presence of surfactant lipids and the hydrophobic surfactant proteins. These findings demonstrate that M. pneumoniae is likely to be recognized by SP-D in the alveolar environment and that primary determinants recognized on the organism are lipid components of the cell membrane.

Animals↗