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Jota Watanabe

Publications and source records attributed to Jota Watanabe.

9 recordsLinked to original sources
PubMed2006

Measuring human complement activation by HLA antibodies.

CONTEXT: The clinical significance of HLA antibodies in transplantation depends on their ability to activate complement, which is measured by the standard complement-dependent cytotoxicity test. Recent reports indicate that C3b measurement on target cells may be a better indicator of human complement activation than standard cytotoxicity. OBJECTIVE: To determine the characteristics of the test, the role of other complement components, and the potential influence of the patient's own complement activity. DESIGN: The T-cell deposition of multiple complement components triggered by HLA alloantibodies was evaluated by flow cytometry using normal human serum as the source of complement. Complement activity in patients' sera was measured after activation with a standard antibody. RESULTS: When HLA antibodies activate complement, C3b deposition is usually highest, followed by that of C4b and C5b. Deposition of C1q, C3d, iC3b, or C5b-9 was low or undetectable in this study. The C5 was activated only when relatively high levels of C3b were present. There was a critical concentration of antibody, unique for each patient, below which activation of C3 declined abruptly. The complement activity in the serum of candidates for liver, heart, and lung transplantation that was tested with a standard antibody was similar to normal serum. In contrast, kidney transplant candidates exhibited higher complement activity. Unexpectedly, serum C3 activity was retained for at least 72 hours after collection. CONCLUSIONS: Measurement of C3b, and in some instances C4b or C5b, offers a better definition of the ability of HLA antibodies to activate human complement than tests that are in current use. The results provide a necessary baseline to conduct clinical correlation studies.

Complement Activation↗
PubMed2005

The usefulness of early laparoscopic surgery for determining a medical treatment plan in severe acute pancreatitis.

A 41-year-old woman presented with sudden onset severe epigastric pain. She was diagnosed as having severe acute pancreatitis (SAP) with an APACHE II score of 10, and initially, general supportive therapy was performed. Because the patient's condition kept worsening, early laparoscopic surgery was performed. It revealed swelling, hemorrhagic necrosis of the pancreas, and massive fluid collection in the abdominal cavity. Kocherization and bursectomy were performed for these lesions, and drainage tubes were indwelled. The white blood cell count (WBC) and serum interleukin-6 value prominently improved shortly after the operation, and the WBC count remained at a low level. The patient gradually recovered and was finally discharged 39 days after her initial presentation. To summarize, we performed a successful exploration for SAP, and we found that postoperative continuous lavage effectively eliminated toxic enzymatic exudates in the abdominal cavity and prevent them from circulating. Regarding SAP with peritonitis, early laparoscopic surgery is very useful for determining the pathological extent of the disease and for selecting appropriate treatment options.

Acute Disease↗
PubMed2005

Downregulation of cytokine release by heat preconditioning of livers used for transplantation in rats.

We evaluated the changes in the levels of released cytokines following heat preconditioning of the livers used in rat liver transplantation. The donor rats in the heat preconditioning (HP) group were subjected to heat preconditioning 48 h before graft harvesting. The liver isografts were preserved in Euro-Collins solution for 8 h, and then transplanted orthotopically. The one-week survival rate of the HP group was significantly better than that of the control (C) group. The serum levels of interleukin-6 and interleukin-10 were significantly lower in the HP group than in the C group. Histological staining revealed that the stagnation of red blood cells and infiltration of neutrocytes were reduced in the HP group. The expression of intercellular adhesion molecule-1 was decreased around the central vein in the HP group, as revealed by immunohistochemistry. These results indicate that heat preconditioning downregulates cytokine release and reduces the frequency of microcirculation disorders.

Animals↗
PubMed2005

Case of emphysematous pyelonephritis in a renal allograft.

Emphysematous pyelonephritis is a rare, but serious complication after renal transplantation. This is a case report of a 49-yr-old female who had a renal transplant for diabetic nephropathy. She presented to ER with about 1 wk history of right lower abdominal pain and fever 15 months after the transplant. She had gross hematuria and mental status changes just prior to presentation. A computed tomography (CT) scan of the abdomen showed extensive retroperitoneal and extraperitoneal air dissecting from the transplanted kidney in the right lower quadrant to the level of the mediastinum. There was air in the urinary bladder. These findings were highly suggestive of extensive emphysematous pyelonephritis. The patient was taken to the operating room emergently and underwent a transplant nephrectomy. Blood culture and urine culture were subsequently positive for Salmonella (serogroup O 6, 8 or C2). Initial blood culture also yielded Enterobacter cloacae. The patient was treated with imipenem, cefepime, flagyl, and diflucan empirically: this was later changed to complete a 6-wk course of ciprofloxacin upon discharge. Her hospital course was complicated by a urinary leak; she was discharged to home on day 21. This is the 12th reported case of emphysematous pyelonephritis occurred in a renal transplant recipient.

Emphysema↗
PubMed2005

IVIG and HLA antibodies. Evidence for inhibition of complement activation but not for anti-idiotypic activity.

The immediate effects of IVIG can be due to the presence of anti-idiotypic antibodies or inhibition of complement, but there is limited data about these possible mechanisms specifically on HLA antibodies (HLA Abs). Potential blocking activity of IVIG on HLA Ab binding and complement activation was investigated by flow cytometry. IVIG did not inhibit the IgG binding of any of 23 sera from sensitized patients containing Abs to several different HLA specificities. In contrast, IVIG produced significant dose-dependent complement inhibition. Low IVIG concentrations could be inhibitory if there was little C3 activation, but high concentrations were needed when C3 was activated more efficiently. The data do not support any significant contribution of anti-idiotypic antibodies against HLA Abs to the activity of IVIG. The results also highlight a relationship between the magnitude of C activation and the C inhibitory effect of IVIG.

Antibodies, Anti-Idiotypic↗
PubMed2004

Human leukocyte antigen antibodies and human complement activation: role of IgG subclass, specificity, and cytotoxic potential.

BACKGROUND: Human leukocyte antigen (HLA) antibodies are defined as complement (C) fixing and clinically relevant based upon the complement-dependent cytotoxicity (CDC) test. However, the sub-lytic activation of individual C components is of critical biologic significance. The requirements of HLA antibodies to activate human C are not known. METHODS: IgG, IgM, IgG subclasses, and human C3b deposition upon T cells were evaluated by flow cytometry with sera from HLA-sensitized patients and human monoclonal HLA antibodies. RESULTS: Comparative studies showed that there was poor correlation between the amount of IgG on target cells and their ability to produce CDC. Human C3b deposition was influenced more by the particular serum/cell combination under study than by the amount of IgG, with some combinations showing high IgG and low C3b and others showing low IgG and high C3b. IgG1 was the predominant IgG subclass in all patients. The other subclasses were low or undetectable and did not correlate with C3b deposition. Human monoclonal HLA antibodies, mostly IgG1, did not activate human C efficiently despite high IgG binding. However, combinations of two monoclonal antibodies to different epitopes of the same antigen did produce significant C3b deposition. CONCLUSIONS: Contrary to common assumptions, CDC, IgG binding, and IgG subclass are poor predictors of human C activation by HLA antibodies. The mix of specificities in a given serum and the antigens of a particular target cell appear to determine the efficiency of C activation. Measuring both antibody and C3b deposition (or other C component) may improve the assessment of donor-recipient compatibility.

Antibodies, Monoclonal↗
PubMed2004

Prognostic significance of Bcl-xL in human hepatocellular carcinoma.

BACKGROUND: Proliferation and apoptosis of liver cancer cells are closely related phenomena. We investigated the correlation between overexpression of Bcl-xL, an anti-apoptosis-related protein of the Bcl-2 family, and the clinical course of hepatocellular carcinoma (HCC). METHODS: Specimens from 7 HCC patients were used for Western blotting and immunoelectron microscopy tests. Samples from 33 HCC patients who had undergone hepatectomies were used for immunohistochemical staining. The degrees of expression of Bcl-xL and Ki-67, as an index of HCC mitosis severity, were each classified into 2 groups. RESULTS: With the use of Western blot analysis, enhanced immunoreactivity of Bcl-xL was found in cancerous specimens. Bcl-xL overexpression was found in cancer specimens in 21 of 33 patients (63.6%). The overall survival (P=.019) and disease-free survival (P=.030) rates of the group overexpressing Bcl-xL were definitely poorer. The Ki-67 higher labeling index LI > 10) group had a poorer survival rate (P=.016). There were significant correlations between Bcl-xL and overall survival and disease-free survival. Multivariate analyses revealed that Bcl-xL, tumor size, histologic portal invasion, and histologic metastatic foci were independent prognostic factors for overall survival and disease-free survival. CONCLUSIONS: These results showed Bcl-xL in HCC specimens, suggesting that Bcl-xL was a significant prognostic factor for disease progression in human HCC.

Adult↗
PubMed2002

Bcl-xL overexpression in human hepatocellular carcinoma.

It is known that proliferation and apoptosis are closely related phenomena in liver cancer cells. In this study, using surgical specimens from 42 patients with hepatocellular carcinoma (HCC), we investigated the expression and localization of Bcl-xL, an antiapoptosis-related protein of the Bcl-2 family. Using Western blotting, Bcl-xL expression was detected in both cancerous and non-cancerous specimens from all of the HCC patients, and elevated Bcl-xL levels were found in cancerous specimens from two thirds of the patients. In normal human liver specimens, Bcl-xL was found mainly in the cytoplasm of hepatocytes, although it was also found in the cytoplasm of bile duct cells in Glisson's capsule by immunohistochemical staining. To the best of our knowledge, this is the first report of Bcl-xL overexpression and localization in HCC specimens. Bcl-xL was found not only in the cytoplasm of HCC cells, but also in the nuclei of some HCC cells, suggesting that Bcl-xL is involved in the progression of HCC cells in vivo.

Adult↗