Biomedical subjects

K Wakasa

Publications and source records attributed to K Wakasa.

At least 37 records · Page 2Linked to original sources

PubMed2001

Appraisal of transarterial immunoembolization for hepatocellular carcinoma: a clinicopathologic study.

Recurrence of hepatocellular carcinoma (HCC) is frequent, even after apparently curative resection. Preoperative transcatheter arterial chemoembolization (TAE) does not improve disease-free survival after hepatic resection. We previously reported the potential usefulness of transarterial immunoembolization (TIE), a newly developed arterial embolization technique using OK-432 and fibrinogen, as preoperative treatment. In this study, we further investigated the effect of TIE by histologic examination of the resected specimens and compared it with conventional TAE in a prospective nonrandomized manner. Thirty-nine patients underwent TIE (n = 17) or TAE (n = 22) before curative hepatectomy for HCC. Transarterial immunoembolization was performed according to the standard protocol using OK-432, fibrinogen, and thrombin. Histologic changes in cancerous and noncancerous liver tissues were examined at different stages after TIE. Histologic grading of cancer cell injury according to the modified Shimosato criteria (Grades 0-IV, in increasing order of severity of cell injury) and postoperative disease-free survival were compared between the two groups. Based on the results of histopathology, TAE was more effective than TIE against the main tumor. In contrast, TIE was significantly more effective than TAE against extracapsular invasion and intrahepatic metastasis. Disease-free survival after hepatectomy tended to be better in patients pretreated with TIE than TAE. Postoperative tumor recurrences in the TIE group (n = 4) occurred in the nontreatment regions, whereas tumor recurrences in TAE group developed mostly (8 of 11 patients) in treated liver regions. Based on results of histologic examination, TIE seems to be more effective than conventional TAE against extracapsular invasion and intrahepatic metastasis. Data for disease-free survival and recurrence site suggest TIE may be a useful preoperative treatment.

Antineoplastic Agents↗

PubMed2001

Expression of p57/Kip2 protein in pancreatic adenocarcinoma.

INTRODUCTION: Evaluation of the biologic character of carcinomas requires understanding of cell cycle regulators. AIMS: To investigate p57 expression in human pancreatic adenocarcinoma and cyst adenoma. METHODOLOGY: We examined the expression of p57(Kip2), a member of the Cip/Kip family, in 45 pancreatic adenocarcinomas, 7 cystadenomas, and 7 chronic pancreatitis cases. RESULTS: The p57 labeling index (LI) in duct epithelia in chronic pancreatitis averaged 32.8+/-8.3 and was significantly higher than in normal duct epithelia (18.8+/-6.6; p = 0.0011). For the carcinoma, the LI averaged 46.0+/-20.9, which was significantly higher than that for normal duct epithelia (p < 0.0001) and cystadenoma (16.0 11.2; p = 0.0007). However, it was significantly reduced in cases with stage IV disease (p = 0.0351), lymph node metastasis (p = 0.0003), larger size (p = 0.0094), capsular invasion (p = 0.0462), lymphatic invasion (p = 0.0351), and cell proliferating activity (p = 0.0002). In multivariate analysis, p57 LI in pancreatic adenocarcinoma was independently linked to high proliferating activity (p = 0.0230). CONCLUSION: These results suggest that p57 plays a role in the hyperplastic change of the ducts in chronic pancreatitis and that pS7 overexpression contributes to the downregulation of cell proliferation, and its decreased expression contributes to the progression of pancreatic adenocarcinoma.

Adenocarcinoma↗

PubMed2001

Characterization of rice anthranilate synthase alpha-subunit genes OASA1 and OASA2. Tryptophan accumulation in transgenic rice expressing a feedback-insensitive mutant of OASA1.

Anthranilate synthase (AS) is a key enzyme in the synthesis of tryptophan (Trp), indole-3-acetic acid, and indole alkaloids. Two genes, OASA1 and OASA2, encoding AS alpha-subunits were isolated from a monocotyledonous plant, rice (Oryza sativa cv Nipponbare), and were characterized. A phylogenetic tree of AS alpha-subunits from various species revealed a close evolutionary relationship among OASA1 and Arabidopsis ASA2, Ruta graveolens AS alpha 2, and tobacco ASA2, whereas OASA2, Arabidopsis ASA1, and R. graveolens AS alpha 1 were more distantly related. OASA1 is expressed in all tissues tested, but the amount of its mRNA was greater in panicles than in leaves and roots. The abundance of OASA2 transcripts is similar among tissues and greater than that of OASA1 transcripts; furthermore, OASA2 expression was induced by a chitin heptamer, a potent elicitor, suggesting that OASA2 participates in secondary metabolism. Expression of wild-type OASA1 or OASA2 transgenes did not affect the Trp content of rice calli or plants. However, transformed calli and plants expressing a mutated OASA1 gene, OASA1(D323N), that encodes a protein in which aspartate-323 is replaced with asparagine manifested up to 180- and 35-fold increases, respectively, in Trp accumulation. These transgenic calli and plants were resistant to 300 microM 5-methyl-Trp, and AS activity of the calli showed a markedly reduced sensitivity to Trp. These results show that OASA1 is important in the regulation of free Trp concentration, and that mutation of OASA1 to render the encoded protein insensitive to feedback inhibition results in accumulation of Trp at high levels. The OASA1(D323N) transgene may prove useful for the generation of crops with an increased Trp content.

Amino Acid Sequence↗

PubMed2001

Influence of previous interferon therapy on recurrence after resection of hepatitis c virus-related hepatocellular carcinoma.

Interferon (IFN) therapy decreases the incidence of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV). One hundred and fifty-nine consecutive patients who underwent liver resection for HCV-related HCC were studied. In 17 (group 1) of the 159 patients, HCC was detected during or after IFN therapy. The incidences of recurrence after surgery in the group 1 patients and the other 142 patients (group 2) were compared. Eight patients had a complete response to IFN, 4 had a partial response, and 5 had no response. The proportion of patients without HCV viremia was significantly higher in the group 1 patients (P < 0.0001). The tumor-free survival rate was significantly higher in the group 1 patients (P = 0.0010). By multivariate analysis of various risk factors for recurrence, no previous IFN was a significant independent risk factor for recurrence (risk ratio = 6.336; 95%CI, 1.512 - 26.50). The patients with HCC who underwent IFN therapy previously are good candidates for liver resection because recurrence after the operation was rarely observed.

Aged↗

PubMed2001

Haemorrhagic hepatic cyst: a differential diagnosis of cystic tumour.

A 63-year-old man was found on ultrasound examination to have a hepatic cystic mass with a mural nodule, which was mildly enhanced on contrast enhanced CT and MRI. At surgery, the cystic fluid was haemorrhagic and histological examination of the mural nodule demonstrated an organized haematoma. This case is of interest in that an apparent mural nodule was present in a non-neoplastic cyst. Haemorrhagic hepatic cyst with an organized haematoma should be included in the differential diagnosis of cystic neoplasms.

Cysts↗

PubMed2001

Pancreatic mass due to chronic pancreatitis: correlation of CT and MR imaging features with pathologic findings.

OBJECTIVE: The purpose of this study was to identify helical CT and MR imaging features of pancreatic masses (focal enlargement) due to chronic pancreatitis and their correlation with pathologic findings. CONCLUSION: When histologic fibrosis is uniformly present through the pancreas in patients with chronic pancreatitis, there is no demarcation of masses due to chronic pancreatitis. When there is a greater degree of histologic fibrosis in the masslike part of the pancreas, the mass is often demarcated from the remaining pancreas, and the enhancement pattern on two-phase helical CT and dynamic gadolinium-enhanced MR imaging mimics that of pancreatic adenocarcinoma.

Adenocarcinoma↗

PubMed2001

Expression of p73 and p63 proteins in pancreatic adenocarcinoma: p73 overexpression is inversely correlated with biological aggressiveness.

The significance of p53, a prominent tumor suppressor gene, and its product in various neoplasms including pancreatic adenocarcinoma has been established. We investigated the expression of two types of homologue of p53, p73 and p63, in pancreatic adenocarcinoma by means of immunohistochemistry. Overexpression of p73 was observed in 45.6% of the cases and this phenomenon was more frequently seen in cystic adenocarcinomas than in ductal carcinomas. Furthermore, p73 overexpression was inversely linked to lymph node metastasis, tumor size, and Ki-67 labeling index. On the other hand, p63 overexpression was observed in 68.2% of the cases, but was not related to any clinicopathological features. No correlation was established between the expression of these proteins and aberrant p53 expression. These results suggest that decreased expression of p73 protein and over-expression of p63 protein may play a role in the development of pancreatic adenocarcinoma.

Adenocarcinoma↗

PubMed2001

Metachromasia of the endocervical epithelium in women treated with gonadotropin releasing hormone agonist.

Endocervical epithelium from women treated with gonadotropin releasing hormone agonist (GnRH agonist) were compared with those from untreated women, using metachromatic stain with toluidine blue and immunohistochemistry, for estrogen and progesterone receptors. Smaller endocervical epithelium with lower intraepithelial mucus and more prominent nuclear distribution of estrogen receptors were seen in a woman who was treated for twelve months with GnRH agonists, as compared with those from an untreated premenopausal woman.

Adult↗

PubMed2001

Metachromasia of the endocervical epithelium for delineating the internal os.

OBJECTIVE: To study the metachromatic stainability of the endocervical epithelium. STUDY DESIGN: Surgical specimens that included endocervical epithelium were deparaffinized and stained with toluidine blue at various pH levels and after enzyme digestion. Glycosaminoglycans were separated from endocervical tissue and analyzed by electrophoresis. RESULTS: The endocervical epithelium stained metachromatically purple with toluidine blue in pH 4.1 buffer, but the staining disappeared after chondroitinase digestion. The electrophoretic mobility of the glycosaminoglycan fraction separated from the endocervical epithelium was compatible with nonsulfated chondroitin. CONCLUSION: Endocervical epithelium was identifiable from metachromatic staining below the internal os, and the electrophoretic results of the tissue extract suggested that nonsulfated chondroitin is the main component of glycosaminoglycans in endocervical epithelium.

Cervix Uteri↗

PubMed2001

Unusual CT and MR findings of inflammatory pseudotumor in the parapharyngeal space: case report.

Unusual MR and CT findings of an inflammatory pseudotumor in the parapharyngeal space of a 73-year-old woman are reported. The mass was hypointense on T1- and T2-weighted images and demonstrated ring enhancement after contrast medium injection. Punctated calcifications were scattered at the periphery. Inflammatory pseudotumors in the parapharyngeal space are rare, and only three cases have been reported. The possible pathogenesis and varieties of inflammatory pseudotumors are discussed.

Aged↗

PubMed2000

Effect of viral status on recurrence after liver resection for patients with hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND: Risk factors for recurrence after resection of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) require more precise definition. METHODS: Forty patients who underwent liver resection for HBV-related HCC were studied. Their clinical findings, laboratory data (including viral status), pathologic findings, and operative methods were evaluated for recurrence risk in univariate and multivariate analyses. RESULTS: The HB envelope (HBe) antigen, wild-type HBV, intrahepatic metastases, elevated serum activities of aspartate aminotransferase and alanine aminotransferase, and moderately or severely active hepatitis were more likely to be found in patients with a high viral load than in patients with a low viral load. Precore mutant-type HBV was more likely to be found in patients with a low viral load than in patients with a high viral load. The platelet count was significantly lower in the patients with a high viral load. A high viral load, the presence of wild-type HBV, the absence of anti-HBe, the absence of precore mutant-type HBV, Child score B, a low platelet count, and a positive surgical margin were risk factors for recurrence in univariate analysis. A nonanatomic resection tended to be a risk factor. A high viral load and positive surgical margin were independent risk factors for recurrence. CONCLUSIONS: The measurement of viral load and detection of anti-HBe, wild-type HBV, and precore mutant-type HBV are useful for estimating a patient's prognosis after resection of HBV-related HCC.

Adult↗

PubMed2000

Assessment of decontamination methods as pretreatment of silanization of composite glass fillers.

In terms of mechanical properties and durability, the surface of glass fillers should be decontaminated in order to optimize the silanization process for the production of resin composites. The objective of this study was to evaluate the decontamination efficiency of 18 cleaning methods on glass fillers as pretreatment of silane coupling. X-ray photoelectron spectroscopy revealed that SiO(2) boiled with a 5% sodium peroxodisulfate aqueous solution for 15 min, followed by ultrasonic rinsing with acetone for 30 min was most effective among all the decontamination methods investigated. In addition, nano-indentation measurements on SiO(2) treated by the above-mentioned method revealed that the surface was not significantly weakened as compared to untreated SiO(2). The results of this study should lead to an improved filler-matrix coupling and thus contribute to the development of better wear and fatigue-resistant composites. Therefore, sodium peroxodisulfate is proposed as a presilanization filler decontamination step in the production process of resin composites.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2000

Risk factors for recurrence after resection of hepatitis C virus-related hepatocellular carcinoma.

Although there have been many studies of the risk factors for recurrence after resection of hepatocellular carcinoma (HCC), the subjects were patients with various viral status in the previous studies, and hepatitis C viremia has not been evaluated. We investigated risk factors, including hepatic C viremia and histologic findings of noncancerous hepatic tissue, for recurrence after resection of hepatitis C virus (HCV)-related HCC. A total of 223 patients who underwent liver resection for HCV-related HCC were studied. HCV viremia, laboratory data, degree of HCC malignancy, histologic findings in noncancerous hepatic tissue, preoperative interferon therapy, and operative methods were evaluated for recurrence risk by univariate and multivariate analyses. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin, and the proportion of patients with a high histologic activity score (mild to severe active hepatitis) were significantly higher in patients with HCV viremia than in those without viremia. Serum albumin was significantly lower in patients with HCV viremia. By univariate analysis, older age (> 65 years old), HCV viremia, elevated AST (> 40 IU/L) and ALT (> 45 IU/L), large tumors (> 40 mm), multiple HCCs, moderately or poorly differentiated HCC, portal invasion, mild to severe active hepatitis, and lack of preoperative interferon therapy were risk factors for recurrence. Multivariate analysis showed that older age, HCV viremia, high AST, multiple HCCs, and portal invasion were independent risk factors. For HCV-related HCCs, not only the degree of malignancy of the HCC but also HCV viremia and active hepatitis are risk factors for recurrence.

Aged↗

PubMed2000

Additional hepatocellular carcinomas undetectable before surgery.

The presence of small additional hepatocellular carcinomas (HCCs) undetectable before hepatic resection is a crucial topic for hepatic surgeons. We assessed the incidence of pathologically diagnosed multiple HCCs in 267 patients who underwent hepatic resection for HCC. Ninety-five additional HCC nodules were detected in 72 of the patients (27%). The survival rate of these 72 patients was significant worse than for the 195 with single nodular HCC (p = 0.0013). Twenty-one (22%) were detected before surgery, 29 (31%) during surgery, and 45 (47%) on pathologic examination after surgery. The mean nodule diameters for each group were 2.1, 1.0, and 0.9 cm, respectively (p < 0.0001). None of the 21 nodules detected before surgery was well differentiated, whereas 30 of the 74 nodules in the other two groups were well-differentiated. Although the mean nodule diameter of the well-differentiated HCC group was the smallest, there was no significant difference among the three groups assigned according to tumor differentiation (p = 0.2355). Altogether, 9 of 16 patients with additional nodules detected before surgery (56%) and 49 of 59 with additional nodules detected during or after surgery (88%) had cirrhosis of the liver. The odds ratio for detecting a new HCC nodule during or after surgery in the presence of cirrhosis was 5.444 (p = 0.0087). Improvement in the detection of small additional HCC nodules before and during surgery and meticulous follow-up after surgery are necessary for patients with cirrhosis. For patients without cirrhosis, surgical treatment may be performed according to the results of preoperative imaging studies.

Analysis of Variance↗

PubMed2000

Granular cell tumor of the male breast: report of a case.

We treated a 35-year-old male with a granular cell tumor in the right breast. Physical examination revealed a solid, flattened, round 3.2 x 2.5-cm mass with an irregular surface, covering skin fixation and right axillary lymphadenopathy. Mammography revealed a well-demarcated high-density mass with a minimal starburst appearance. Ultrasonography revealed a hypoechoic, nonhomogeneous mass with an acoustic shadow. Several enlarged lymph nodes in the right axilla were removed at the time of breast tumor excision. Histologically, the tumor featured nests of round or polygonal cells with abundant eosinophilic cytoplasmic granules and small round nuclei, and the enlarged lymph nodes in the right axilla exhibited no metastasis. Immunohistochemically, there was positive staining for S-100 protein, neuron-specific enolase, and vimentin. The tumor also stained for macrophage CD-68, alpha1-antichymotrypsin, and myoglobin. These immunohistochemical findings suggested the tumor cells to be undifferentiated mesenchymal cells which demonstrated the properties of neurogenic cells and histiocytes.

Adenocarcinoma↗

PubMed2000

Presence of active hepatitis associated with liver cirrhosis is a risk factor for mortality caused by posthepatectomy liver failure.

The histologic activity of associated hepatitis was examined in 285 patients who underwent hepatectomy for hepatocellular carcinoma (HCC), to determine if the histologic activity is an independent risk factor for postoperative mortality due to liver failure. The proportion of patients with liver cirrhosis who died due to liver failure (6/180, 3.3%) was not different from that of patients with chronic hepatitis (2/68, 2.9%). However, mortality was higher in patients with liver cirrhosis and active hepatitis (4/46, 8.7%) than in those with cirrhosis and inactive hepatitis (2/134, 1.5%, P < 0.05). Such difference was not observed in the chronic hepatitis group. Multivariate analysis showed that clearance of indocyanine green at 15 min (ICGR15) and activity of hepatitis were two independent risk factors for postoperative mortality due to liver failure. In conclusion, histologic activity of associated hepatitis should be taken into account in hepatic resection of HCC in cirrhotic liver, in addition to the functional reserve of the liver.

Adult↗

PubMed2000

Chemotherapy-induced acral erythema: report of a case and immunohistochemical findings.

Chemotherapy-induced acral erythema (CAE) is an uncommon and distinct reaction seen in patients receiving high-dose chemotherapy. The exact pathogenic mechanisms of this disorder are still unknown. We report a 27-year-old woman who presented with red, swollen and painful macules on both palms, clinically consistent with this disease. Histological examination demonstrated vacuolar degeneration of the basal cell layer and spongiotic blisters in the epidermis, especially in the atrophied eccrine ducts and papillary oedema with mild perivascular infiltration of mononuclear and hypersegmented neutrophils. Immunohistochemistry showed that the infiltrating mononuclear cells were CD3-CD16+CD56+ leucocyte function antigen-1+, possibly natural killer cells. The eccrine ducts expressed HLA-DR and intracellular adhesion molecule-1 (ICAM-1). Our findings suggest that cell-to-cell interaction between NK cells and keratinocytes in the eccrine apparatus may induce CAE and may be involved in the pathogenesis of the skin reaction in our patient and possibly in this disease.

Adrenal Cortex Hormones↗

PubMed2000

Superparamagnetic iron oxide-enhanced magnetic resonance images of hepatocellular carcinoma: correlation with histological grading.

Superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging has been used for the detection of hepatic tumors. However, little is known about this technique in relation to hepatocellular carcinoma (HCC). The aim of this study was to investigate whether SPIO-enhanced MR imaging can be useful in assessing histological grades of HCC. The authors studied histologically proven tumors including 31 HCCs and 6 dysplastic nodules. The ratio of the Kupffer-cell count in the tumorous tissue relative to that in the nontumorous tissue (Kupffer-cell-count ratio) decreased as HCCs became less well differentiated. The ratio of the intensity of the tumorous lesion to that of the nontumorous area on SPIO-enhanced MR images (SPIO intensity ratio) correlated inversely with Kupffer-cell-count ratio in HCCs and dysplastic nodules (r = -.826, P <.001) and increased as the degree of differentiation of HCCs decreased, indicating that the uptake of SPIO in HCCs decreased as the degree of differentiation of HCCs declined. All of the dysplastic nodules and some well-differentiated HCCs showed hypointense or isointense enhancement, relative to the surrounding liver parenchyma, indicating greater or similar uptake of SPIO in the tumor when compared with nontumorous areas. These results suggest that SPIO-enhanced MR imaging reflects Kupffer-cell numbers in HCCs and dysplastic nodules, and is useful for estimation of histological grading in HCCs, although uncertainties persist in differentiating dysplastic nodules from well-differentiated HCCs.

Aged↗