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Biomedical subjects

A Saito

Publications and source records attributed to A Saito.

At least 145 records · Page 8Linked to original sources
PubMed2001

[Comparison of photometric, electrochemical and post-column fluorescence detection for the determination of flavonoids by HPLC].

For the analysis of flavonoids by HPLC, we compared three different detection methods, namely UV, electrochemical detection and post-column chelation with aluminum followed by fluorescence detection. Ten flavonoids were used: apigenin, myricetin, luteorin, taxifolin, quercetin-3-O-sulfate, kaempferol, isorhamnetin, isoquercitrin, quercetin and rutin. Nine flavonoids except apigenin were efficiently detected by the electrochemical method with a detection limit of 0.025-0.05 pmol. Flavonols having free 3-hydroxyl and 4-keto oxygen formed a fluorescent complex by post-column chelation and were detected by the fluorescence method. The detection limit of the fluorescence method was 0.05-0.5 pmol. Nine flavonoids except taxifolin were detected by the UV method (absorbance at 370 nm), but the detection level was poor (5-10 pmol). Flavonols added to human plasma were recovered by solid phase extraction, and were analyzed using the three detection methods. Most of the flavonols were efficiently detected by the electrochemical and fluorescence methods, and the detection limits were similar to those of standard samples.

Adult↗
PubMed2001

Usefulness of endoscopic ultrasonographic analysis of variceal hemodynamics for the treatment of esophageal varices.

The correlation of between the endoscopic findings of esophageal varices and endoscopic ultrasound findings of the collaterals outside the esophageal wall in patients with portal hypertension remains unclear. We investigated the relationship between esophageal varices and the collaterals by endoscopy and endoscopic ultrasound. Moreover, we investigated the correlation between the collaterals around the esophagus and recurrence of esophageal varices in patients with portal hypertension who had undergone endoscopic injection sclerotherapy. The collaterals were divided into two groups: 1; those with peri-esophageal collateral veins (peri-ECVs) adjacent to the muscularis externa of the esophagus, and 2; those with para-esophageal collateral veins (para-ECVs) distal to the esophageal wall without contact with the muscularis externa. Peri- and para-ECVs were scored as mild or severe according to the stage of development. According to endoscopy, the varix form was significantly larger in severe peri-ECVs group than in mild peri-ECVs group. In contrast, the varix form did not differ significantly between the mild and severe para-ECVs group. The prevalence of perforating veins increased according to the varix form. With regard to variceal recurrence, in patients with variceal recurrences, EUS findings included a significantly higher incidence of severe-type peri-ECVs, a significantly larger number of perforating veins, and a significantly larger diameter of perforating veins compared with patients without recurrence. Moreover, when EUS found the abnormalities when no endoscopic recurrence was found, the results were the almost same as the findings when EUS was performed at the same time when endoscopic recurrence was found. In conclusion, the presence of severe peri-ECVs and large perforating veins in the esophageal wall strongly correlates with occurrence and recurrence of esophageal varices in patients with portal hypertension. An understanding of these EUS abnormalities on the basis of hemodynamics around the esophagus is thought to be important for management of esophageal varices in patients with portal hypertension.

Collateral Circulation↗
PubMed2001

True hemangiopericytoma of the nasal cavity.

Two cases of nasal tumors with pericytic myoid differentiation are reported. The tumors occurred in a 77-year-old woman and a 60-year-old man as polypoid lesions covered by normal mucosa. Histologically, the tumors were composed of uniform short spindle or stellate cells with indistinct cell borders arranged in narrow and short fascicles. Numerous blood vessels of various sizes were common in both cases. The tumor cells of both cases stained intensely with anti-vimentin and anti-actin antibodies, but not with anti-desmin, CD34, or anti-high-molecular-weight caldesmon antibodies. Ultrastructural examination revealed well-developed actin thin filaments with dense bodies, subplasmalemmal plaques, intercellular junctions, and irregular discontinuous basement membranes. These histopathologic features suggest true pericytic differentiation of the tumors (true hemangiopericytoma), unlike soft tissue-type hemangiopericytoma. Generally, sinonasal hemangiopericytomas are subdivided into soft tissue-type hemangiopericytomas and true hemangiopericytomas identical to the cases presented here. Soft tissue-type hemangiopericytomas are frequently highly aggressive, whereas true hemangiopericytomas show localized benign behavior. Sinonasal true hemangiopericytomas should be strictly differentiated from soft tissue-type hemangiopericytomas.

Actins↗
PubMed2001

Pseudosarcomatous myofibroblastic tumor and myosarcoma of the urogenital tract.

OBJECTIVE: Pseudosarcomatous myofibroblastic tumors (PMTs) of the urogenital tract are rare but distinctive lesions. Despite their benign behavior, they are frequently misinterpreted as leiomyosarcomas and rhabdomyosarcomas in preoperative biopsies and even in resected specimens because of their atypical spindle-cell features. Precise diagnosis of PMTs is important to avoid unnecessary radical therapy. We analyzed urogenital myoid tumors to clarify which of their characteristics are useful for the differential diagnosis. METHODS: We evaluated 7 urogenital myoid tumors consisting of 3 PMTs, 2 leiomyosarcomas, and 2 rhabdomyosarcomas. We studied the expression of various immunohistochemical muscle-cell markers including desmin, muscle-specific actin, alpha-smooth muscle actin, high-molecular-weight caldesmon, and myogenin. RESULTS: Desmin, muscle-specific actin, and alpha-smooth muscle actin were noted variably in all tumor types, whereas high-molecular-weight caldesmon was expressed only in leiomyosarcomas, and myogenin was expressed only in rhabdomyosarcomas. CONCLUSION: High-molecular-weight caldesmon and myogenin are useful for differentiating urogenital PMTs from myosarcomas.

Actins↗
PubMed2001

Expression of enzymes and oncogene induced after radiotherapy and/or chemotherapy in patients with brain tumors.

The relationship between the degree of the expression of Cu/Zn SOD, GST-pi and bcl-2 in the initial and recurrent tumor tissue after radiotherapy and/or chemotherapy and the cellular heterogeneity obtained from DNA content by image cytometry was investigated. Subjects were 7 patients who had glial tumors which were surgically removed at onset and removed a second time at recurrence. Radiotherapy and chemotherapy were also administered after initial resection. Immunoreactivity for copper/zinc super oxide dismutase (Cu/Zn SOD), GST (glutathione-S-transferase)-pi, and bcl-2 were evaluated from routinely prepared tissue blocks. Tumors were classified into two groups by cytometric analysis of DNA ploidy in the G2M cell cycle phase. One tumor group consisted of single clonal cells in both the initial and recurrent tumors and the other group consisted of tumors with polyclonal cells in the initial and recurrent tumor. In this study, one patient (case 3) with single clonal cell glioblastoma at recurrence did not show high Cu/Zn SOD activity after radiotherapy and chemotherapy but showed a short survival time after recurrence. In three patients (cases 1, 2, 3) with single clonal-cell glioblastoma, the recurrent tumor cells showed high GST-pi immunoreactivity and survival time was short after recurrence. Tumor cells in two patients (cases 5, 7) with single clonal cell anaplastic glioma at recurrence, showed high GST-pi immunoreactivity and had a short survival time after recurrence. In three single clonal glioblastomas (cases 1, 2, 3), the recurrent tumor showed the increased bcl-2 immunoreactivity and showed a short survival time after recurrence. In two patients (case 5, 7) with single clonal cell anaplastic glioma at recurrence, tumor cells showed a high bcl-2 immunoreactivity and these patients showed a short survival time after recurrence. Although the number of subjects is very small, our study shows that the immunoreactivity of bcl-2 and GST-pi in malignant gliomas may be very important factors in radio- and chemosensitivity, and shows that GST-pi is induced by radiation and anti-cancer drugs.

Adult↗
PubMed2001

[Schwannoma of the cervical spinal cord with cervical angina: a case report].

A case of schwannoma of the cervical spinal cord presenting with cervical angina is reported. A 49-year-old man was admitted to our hospital with severe chest pain, cold sweats, and unconsciousness. Extensive cardiac examination showed no abnormal findings. Neurological deficits were muscular weakness and atrophy of the left arm, bilateral hypersthesia of the arms, and hyporeflexia of the left biceps. MRI revealed a tumor in the left side of the spinal canal between C4 and C5. The diagnosis was neurinoma of the left nerve root in C5. The tumor was completely removed surgically by laminectomy. Surgery confirmed that the tumor had originated from the left posterior root of C5 and that, histologically, it was schwannoma. The severe chest pain immediately disappeared after removal of the tumor with only dull post-operative chest pain remaining. We hypothesized that the severe chest pain was protopathic pain caused by compression of the anterior C5 root by the tumor and/or disturbance of the inhibitory pain mechanisms of the sympathetic nerve located in the posterior horn of the spinal cord. It must be kept in mind that cervical angina caused by spinal schwannoma is one of the differential diagnoses of chest pain.

Cervical Vertebrae↗
PubMed2001

Tentorial enhancement on MR images is a sign of cavernous sinus involvement in patients with sellar tumors.

BACKGROUND AND PURPOSE: This study was undertaken to analyze enhancement patterns of the dura around sellar tumors and to compare the results with tumor invasion or compression of the cavernous sinuses. Postoperative enhancement patterns on MR images were compared with preoperative findings. METHODS: Contrast-enhanced coronal and sagittal MR images were examined prospectively in 96 patients with sellar tumors (65 macroadenomas, 15 microadenomas, 14 Rathke cleft cysts, and two chordomas at the sella). All patients underwent surgical treatment, and pre- and postsurgical features on MR images were compared. RESULTS: Presurgical MR images showed dural enhancement in 36.5% of the patients: asymmetric tentorial enhancement in 24 patients, symmetric tentorial enhancement in seven, and sphenoidal ridge or clivus enhancement in four. Asymmetric tentorial enhancement disappeared after surgical decompression in seven patients. For evaluation of cavernous sinus invasion ipsilateral to the enhancement, sensitivity and specificity of the asymmetric tentorial enhancement sign were 81.3% and 86.3%, respectively. Sensitivity and specificity of the sign were 42.9% and 93.6% for cavernous sinus involvement, including compression and invasion. CONCLUSION: Asymmetric tentorial enhancement is a useful sign in the diagnosis of invasion or severe compression of the cavernous sinus by sellar tumor. The sign may represent venous congestion or collateral flow in the tentorium due to obstructed flow in the medial portion of the cavernous sinus.

Adenoma↗
PubMed2001

[Induction of mucosal immunity to mycobacterial heat shock protein (hsp) 65 by colonic inoculation of plasmid DNA encoding hsp65].

Mycobacterial heat shock protein (hsp) 65 has more than 50% sequence homology with human hsp60 and immune responses against mycobacterial hsp65 may cross-react with human hsp60 and could cause autoimmune diseases including inflammatory bowel diseases (IBD). Since the colonic mucosa is a main inflammatory site in IBD, mucosal immunity to hsp65 may be more important for the mucosal inflammation than systemic immunity to hsp65. We inoculated plasmid DNA (pDNA) encoding mycobacterial hsp65 (pACB-hsp 65) into the colon of Wistar rats and evaluated the mucosal humoral immune response and the effect of these immune responses on the colonic mucosa. Four weeks after pDNA inoculation, significantly elevated titers of hsp65-specific IgA antibody were seen in fecal extracts of rats immunized intra-colonic mucosa with pACB-hsp65 (40 +/- 9 U/ml), whereas the fecal IgA antibody titers of rats inoculated intradermal with pACB-hsp65 did not arise (8 +/- 5 U/ml). Colonic inoculation of pACB-hsp65 induced systemic and mucosal immune responses to hsp65. However, macroscopic and histological examinations of the colonic mucosa inoculated with pACB-hsp65 showed no evidence of mucosal damage. These results suggested that the mucosal immunity to hsp65 on the colonic mucosa may not play a crucial role in the induction of colonic mucosal inflammation as was seen in IBD.

Animals↗
PubMed2001

[Clinical features in six patients with liver abscess caused by Streptococcus milleri].

Among 39 patients with pyogenic liver abscess who were admitted to our institute, six (15%) were infected by Streptococcus milleri (S. milleri). We investigated clinical features of these six patients. There were five males and one female, aged 43-81 years old (mean: 61). Five of the six patients had underlying illness. All patients had fever, and three of them complained of abdominal pain. Three patients had mixed infections; particularly intraoral anaerobes, Fusobacterium, were found in two of the three patients. There were no differences in clinical features between patients with S. milleri liver abscess and those with other bacterial liver abscess. In conclusion, on selecting antibiotics for the treatment of liver abscess, it is necessary to consider the S. milleri and intraoral anaerobes.

Adult↗
PubMed2001

Hepatitis B virus concentrations in serum determined by sensitive quantitative assays in patients with established chronic hepatitis delta virus infection.

To clarify the correlation between hepatitis B virus (HBV) DNA levels and serum alanine aminotransferase (ALT) levels in patients with established chronic hepatitis delta virus (HDV) infection, sensitive HBV quantitative assays were used for the study. Thirty-four consecutive patients with chronic liver disease who were positive for both hepatitis B surface antigen (HBsAg) and antibody to HDV (anti-HDV), including 19 patients with chronic hepatitis, 8 patients with liver cirrhosis and 7 patients with hepatocellular carcinoma. All were negative for hepatitis Be antigen (HBeAg) and positive for antibody to HBeAg. HBV DNA was detected in 25 (73.5%) of the 34 patients using real-time detection PCR, and the HBV DNA levels of these patients were significantly lower compared with HBeAg status and ALT level-matched patients with chronic liver disease positive for HBsAg but negative for anti-HDV. There was no correlation between serum HBV DNA and ALT levels among the 34 patients with chronic liver disease positive for anti-HDV. Whereas serum ALT levels in anti-HDV-positive HBsAg carriers with HDV RNA were significantly higher than those without HDV RNA. Liver damage in patients with established chronic HDV infection may be caused mainly by ongoing HDV infection not by HBV replication.

Adult↗
PubMed2001

[Thrombosis of the abdominal aorta in a patient with nephrotic syndrome].

Nephrotic syndrome frequently causes thromboembolic complications in veins. Arterial thrombosis, however, is relatively rare. We report the case of a 47-year-old male with nephrotic syndrome complicated with abdominal aortic thrombosis. The patient complained of pain in the bilateral lower extremities 2 weeks after the development of nephrotic syndrome. The aortogram revealed complete occlusion of the abdominal aorta just below the origin of the inferior mesenteric artery. Necrosis of the legs extended rapidly, and he eventually lost his legs. Among various predisposing factors, hypercoagulability associated with nephrotic syndrome seemed to be responsible for the development of thrombosis. Thrombotic complications are sometimes serious in the nephrotic patient. Assessment for the risk factors is required to warrant prophylactic anticoagulation.

Amputation, Surgical↗
PubMed2001

[Characterization of cryoglobulin, M protein, low molecular weight IgM in a patient with chronic hepatitis C and type II mixed cryoglobulinemia].

The common extrahepatic manifestation of hepatitis C virus(HCV) infection is mixed cryoglobulinemia. We have analyzed serum cryoglobulin, IgM and various antibody activities from a patient with chronic hepatitis C and type II cryoglobulinemia. Cryoprecipitates were consisted of polyclonal IgG and monoclonal IgM-kappa with rheumatoid factor activity. About 20% of total IgM was found to be low molecular weight IgM by gel-filtration and SDS-PAGE. The anti-streptolysin O(ASO) activity measured by Latex agglutination method was found to be markedly elevated despite normal activity by Rantz-Randell method. The patient's serum has revealed to react against bovine gamma globulin, which crosslinked streptolysin O to Latex particles, in a nonspecific manner. Phenotypic analysis of the surface markers on abnormal lymphoid cells from peripheral blood and bone marrow showed monoclonal expansion of B-cell lineage by flow cytometry. The patient was treated with interferon-alpha, which resulted in an improvement of liver dysfunction, decreased amounts of cryoglobulin and IgM. It was concluded that the patient has suffered from lymphoproliferative disorder, namely HCV infection-associated primary macroglobulinemia.

Aged↗
PubMed2001

[A putative immunotherapy with biological response modifiers (BRM) against intractable pulmonary tuberculosis].

The problem of tuberculosis is emerging again with increase in the population of aged people and immunocompromised patients in Japan. It has been well documented that cell-mediated immunity play a central role in host resistance to infection with Mycobacterium tuberculosis. Many recent studies have provided evidences suggesting that the Th1-Th2 cytokine balance may determine the outcome of some diseases: predominant production of Th1 cytokines may prevent the occurrence of infectious diseases caused by intracellularly growing pathogens and Th2 cytokines may be involved in the exacerbation of allergic diseases. On the other hand, IL-12 plays an essential role in the differentiation of Th1 cells from naive T cells, and IL-18 potentiates this effect although it does not show such effect by itself. In previous investigations using gene-disrupted mice, the essential roles for IFN-gamma, IL-12 and IL-18 have been demonstrated. There are several host factors which determines the outcome of mycobacterial infection. Among them, steroid treatment and AIDS are important factors. In this lecture, I addressed the effect of these pathological conditions on Th1-Th2 cytokine balance and outcome of mycobacterial infection using murine models. In both conditions, the exacerbated infection was well correlated with the reduced production of IFN-gamma. Furthermore, I also talked about the relationship between other host factors and balance in the production of Th1 and Th2 cytokines. Using a murine model of fatal infection with M. tuberculosis, we demonstrated the therapeutic effect of Th1-type cytokines against this infection and suggested that immunotherapy with these cytokines may be clinically effective in the intractable infection. We tried a combined therapy with anti-tuberculous agents and IFN-gamma in intractable pulmonary tuberculosis caused by multidrug-resistant pathogen in a patient with insulin-dependent diabetes mellitus. Although no report showing the clinical use of IL-12 in infectious diseases has been seen, clinical trials already commenced for the therapy of malignant neoplastic diseases. It may not be in far future that this cytokine is clinically used for the treatment of infectious diseases. IL-18 has not yet been under the clinical trials.

Adult↗