Biomedical subjects

Kazuhiro Nagaike

Publications and source records attributed to Kazuhiro Nagaike.

8 recordsLinked to original sources

PubMed2006

Serum hepatocyte growth factor activator inhibitor type I (HAI-I) and type 2 (HAI-2) in prostate cancer.

BACKGROUND: Hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are Kunitz-type serine protease inhibitors for hepatocyte growth factor activator (HGFA). We attempted to clarify whether serum levels of HAI-1 and HAI-2 could be a useful marker in patients with prostate cancer. METHODS: Serum levels of HAI-1 and HAI-2 were measured by enzyme-linked immunosorbent assay in 27 patients with benign prostatic hyperplasia (BPH) and 118 patients with prostate cancer. RESULTS: The mean serum levels of HAI-1 in patients with prostate cancer were significantly higher than those in patients with BPH. Furthermore, the serum HAI-1 levels in patients with distant metastasis and hormone resistant prostate cancer were significantly elevated compared with those in patients with organ-confined diseases. There were no significant differences in serum HAI-2 levels among prostate cancer subgroups according to clinical stage. Significantly elevated levels of HAI-1 were detected in 38 patients with prostate cancer before any treatment. CONCLUSIONS: HAI-1 may be a potential tumor marker for prostate cancer. Further studies in large groups of patients are needed to define the clinical value of HAI-1.

Biomarkers, Tumor↗

PubMed2006

Changes in plasma levels of hepatocyte growth factor and its associated factors during pregnancy.

AIM: Hepatocyte growth factor (HGF) was originally identified as a factor that stimulates the mitogenesis of hepatocyte, and also plays a role in maintaining pregnancy. We conducted this study to evaluate the changes in plasma concentrations of HGF and its associated factors during normal pregnancy. METHODS: Blood specimens were obtained from 14 healthy non-pregnant and 175 healthy pregnant and post-partum women (189 women in all). The women's plasma concentrations of total HGF, active HGF, active HGF activator (HGFA), HGF activator inhibitor type 1 (HAI-1) and HGF activator inhibitor type 2 (HAI-2) were determined by enzyme-linked immunosorbent assay. RESULTS: The levels of active HGF and HGF activator were significantly lower in pregnant women compared with those of non-pregnant women. The level of plasma HAI-1 significantly increased as pregnancy progressed, while it fell post-partum. Also, there were no differences in the concentrations of total HGF and HAI-2 in non-pregnant and pregnant women. CONCLUSION: A high concentration of HAI-1 during pregnancy may decrease the plasma level of active HGFA. This may in turn inhibit the activation of the precursor form of HGF, leading to a decrease in the level of plasma active HGF.

Adult↗

PubMed2005

Serum hepatocyte growth factor activator (HGFA) in benign prostatic hyperplasia and prostate cancer.

OBJECTIVES: Hepatocyte growth factor activator (HGFA) is responsible for proteolytic activation of the precursor form of hepatocyte growth factor (HGF). We attempted to clarify whether serum levels of HGFA could be used as a marker for prostate cancer. MATERIAL AND METHODS: Serum levels of total HGF and HGFA were measured by enzyme-linked immunosorbent assay in 99 healthy controls, 27 patients with benign prostatic hyperplasia (BPH) and 119 patients with prostate cancer. RESULTS: : The mean+/-S.D. serum levels of HGFA in untreated prostate cancer and BPH cases were 0.42+/-0.24 and 0.50+/-0.26 ng/ml, respectively (no significant difference). Serum HGFA was significantly elevated in hormone-refractory prostate cancer (stage D3) compared to other stages, while HGF did not significantly differ with regard to clinical stage. CONCLUSIONS: Serum HGFA tends was elevated in patients with advanced stage prostate cancer. Further studies in large groups of patients are needed to clarify the clinical value of HGFA.

Aged↗

PubMed2005

[Proteomics and diagnostic application].

Proteomics research possesses even greater potential than the achievements of genomics research. Clinical tests which more accurately identify pathology are needed. Clinical tests are also classified in terms of the metabolome. On the other hand, the techniques of proteomics research appear to be useful for developing diagnostic systems, not just searching for biomarkers. 2DG and the mass spectrometer are representative proteomics tools, and are now being used in blood tests. It is possible that systemic manifestations will come to be understood on the basis of the data obtained from them, and that they will be used for a variety of screening tests. Use of one of them, SELDI, is particularly interesting. High-throughput protein expression techniques, for example, phage display and the IVV method, are becoming useful for producing innovative high-affinity diagnostic antibodies. Protein chips that use ELISA and fluorescence for detection can be regarded as simultaneous multi-item tests. Up until now there have been chips with several spots, but it should soon become possible to make high-density chips in addition. Array devices for SPR, a new principle for viewing protein-protein interactions, have already been developed. Although they may not be very sensitive, they are useful in antibody tests because they make it possible to measure affinity. Simultaneously using different types of detection systems on the thin gold film of the SPR array would make possible a wider range of tests than ever before. Moreover, enormous chip data processing has the potential to create a new concept in profiling test methodology. Proteomics research such as that described above has the potential to give rise to new concepts in the field of diagnosis.

Biomarkers↗

PubMed2004

Cloning of the varicella-zoster virus genome as an infectious bacterial artificial chromosome in Escherichia coli.

The complete genome of the varicella-zoster virus (VZV) Oka strain has been cloned as a bacterial artificial chromosome (BAC). Following electroporation into Escherichia coli (E. coli) strain DH10B, the VZV BAC was stably propagated over multiple generations of its host. Human embryonic lung (HEL) cells transfected with VZV BAC DNA recovered from DH10B showed cytopathic effect (CPE), and virus spread to neighbouring cells was observed. BAC vector sequences are flanked by loxP sites and, coinfection of the reconstituted virus, with a recombinant adenovirus expressing Cre recombinase removed the bacterial sequences. The resulting recombinant rV02 grew as well as the parental virus in HEL cells. The recombinant VZV will promote VZV research and increase use of the viral genome as an investigative tool.

Adenoviridae↗

PubMed2004

A new immunofluorostaining method using red fluorescence of PerCP on formalin-fixed paraffin-embedded tissues.

Immunofluorostaining, a versatile tissue staining method, is used in biomedical research because of its clear contrast and precise quantification of positive signals. However, its application in clinical diagnosis has been limited. A major obstacle is high fluorescent background of formalin-fixed, paraffin-embedded tissue sections (paraffin sections). On paraffin sections, strong and broad fluorescence of the section overlapping that of conventional fluorescent dyes such as fluorescein isothiocyanate (FITC) prevents detection of target immunofluorescence. To circumvent the background, we selected an albuminous dye, peridinin chlorophyll a protein (PerCP), for immunostaining of human tumor sections with tumor-reactive monoclonal antibodies. Red fluorescence of PerCP clearly distinguished the tumor region within the yellow-green autofluorescence of the section. Furthermore, it was possible to observe tissue morphology simultaneously without any counterstaining; autofluorescence served as counterstaining in this method. Digital quantification of PerCP-stained image intensity correlated (r2>0.99) well with extracted PerCP amount, indicating the usefulness of image quantification. We conclude that this new and simple immunofluorostaining method can be applied to pathological diagnosis of a wide range of conditions, including cancer.

Animals↗

PubMed2004

Establishment and evaluation of cancer-specific human monoclonal antibody GAH for targeting chemotherapy using immunoliposomes.

To establish human monoclonal antibodies suitable for targeting chemotherapy, we prepared a panel of human-mouse hybridomas, using mouse myelomas and lymphocytes of regional lymph nodes excised from cancer patients, and selected antibodies on the basis of their specificity of binding to the surface of viable cancer cells derived from fresh cancer tissues. A selected antibody, named GAH, was found to react with viable cancer cells from 21/22 stomach and 13/20 colon cancer tissues. As for further analysis, complementary DNAs encoding GAH were cloned and recombinant GAH (rGAH) was obtained from established CHO cells transfected with GAH expression vectors. rGAH selectively stained cancer cells in human tissue sections from 13/14 stomach, 4/11 colon, 5/11 mammary, and 0/7 lung cancers, while no positive staining was observed in those of non-tumor and various normal specimens. Notably, using confocal fluorescence microscopy, rGAH was not only bound to the surface of cancer cells, but was also internalized by the cells. The potential of rGAH for intracellular drug delivery was subsequently evaluated using rGAH-conjugated, doxorubicin (DXR)-encapsulated immunoliposomes. The immunoliposomes were also internalized into the cancer cells and finally DXR was delivered to the cell nucleus. Furthermore, the immunoliposomes could inhibit the growth of DXR-insensitive stomach cancer cells (B37) in an in vivo model. These results suggest that a GAH-utilized liposome-targeting technique will provide a potent and useful cancer chemotherapy with broad applications for cancer patients.

Amino Acid Sequence↗

PubMed2002

Comparison of the complete DNA sequences of the Oka varicella vaccine and its parental virus.

The DNA sequences of the Oka varicella vaccine virus (V-Oka) and its parental virus (P-Oka) were completed. Comparison of the sequences revealed 42 base substitutions, which led to 20 amino acid conversions and length differences in tandem repeat regions (R1, R3, and R4) and in an origin of DNA replication. Amino acid substitutions existed in open reading frames (ORFs) 6, 9A, 10, 21, 31, 39, 50, 52, 55, 59, 62, and 64. Of these, 15 base substitutions, leading to eight amino acid substitutions, were in the gene 62 region alone. Further DNA sequence analysis showed that these substitutions were specific for V-Oka and were not present in nine clinical isolates. The immediate-early gene 62 product (IE62) of P-Oka had stronger transactivational activity than the mutant IE62 contained in V-Oka in 293 and CV-1 cells. An infectious center assay of a plaque-purified clone (S7-01) from the V-Oka with 8 amino acid substitutions in ORF 62 showed smaller plaque formation and less-efficient virus-spreading activity than did P-Oka in human embryonic lung cells. Another clone (S-13) with only five substitutions in ORF 62 spread slightly faster than S7-01 but not as effectively as P-Oka. Moreover, transient luciferase assay in 293 cells showed that transactivational activities of IE62s of S7-01 and S7-13 were lower than that of P-Oka. Based on these results, it appears that amino acid substitutions in ORF 62 are responsible for virus growth and spreading from infected to uninfected cells. Furthermore, the Oka vaccine virus was completely distinguishable from P-Oka and 54 clinical isolates by seven restriction-enzyme fragment length polymorphisms that detected differences in the DNA sequence.

Amino Acid Sequence↗