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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 109 records · Page 6Linked to original sources
PubMed2001

Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisation.

The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology.

Antibodies↗
PubMed2001

Oncocytic biliary cystadenocarcinoma is a form of intraductal oncocytic papillary neoplasm of the liver.

Biliary cystadenocarcinoma with oncocytic differentiation was first reported in 1992. This is a report of a second case. The patient (a 71-year-old man) was admitted to our hospital complaining of abdominal fullness. Multicystic lesions were identified in the left hepatic lobe radiologically. The patient died of peritoneal dissemination of carcinoma 20 months later. At autopsy, the tumor of the left hepatic lobe was found to be composed of adjoining multiple cystic lesions and a solid lesion with infiltration of the hepatic hilus and peritoneal dissemination. Histologically, the multicystic lesions were covered by papillary neoplastic epithelial cells with an eosinophilic granular cytoplasm resembling that of oncocytes and a fine fibrovascular core. The cyst wall was fibrous, but there was no mesenchymal stroma. In the solid lesion and infiltrated areas, acidophilic and granular carcinoma cells formed small glandular or solid cord patterns with much mucin secretion (mucinous carcinoma). Immunohistochemically, carcinoma cells of both components were found to contain many mitochondria and showed the phenotypes of hepatocytes and cholangiocytes. Interestingly, the intrahepatic biliary tree also was invaded by carcinoma cells. This may be a case of intraductal oncocytic papillary neoplasm of the left hepatic lobe followed by secondary cystic dilatation of the affected bile duct.

Adenoma, Oxyphilic↗
PubMed2001

Interleukin-1 beta enhances and interferon-gamma suppresses activin A actions by reciprocally regulating activin A and follistatin secretion from bone marrow stromal fibroblasts.

Activin A is a multi-functional cytokine with a potent stimulation on erythroid cell differentiation in the bone marrow. The actions of activin A are determined by a balance of the levels of activin A and its inhibitor, follistatin (FS). However, the regulation of its actions in the bone marrow has been unclear. Here we show that bone marrow-derived stromal fibroblasts are the major source of activin A and FS in the bone marrow, and that the production of activin A is enhanced by interleukin-1beta (IL-1beta) and lipopolysaccharide (LPS), whereas interferon-gamma (IFN-gamma) inhibits the secretion of activin A by stromal fibroblasts. Concomitantly, IL-1beta as well as LPS inhibits and IFN-gamma stimulates FS secretion from stromal fibroblasts. Thus, these cytokines potently regulate activin A actions by reciprocal modulation of activin A and FS secretion from stromal fibroblasts. Because activin A exhibits anti-inflammatory effects in various tissues, up-regulation of activin A actions by IL-1beta and endotoxin in the bone marrow may play a protective role against inflammatory processes as well as anaemia. The present results also suggest that the inhibitory effect of IFN-gamma on erythropoiesis is mediated at least in part by a suppression of activin A actions in bone marrow.

Activins↗
PubMed2001

Expression of MUC1 and MUC2 and carbohydrate antigen Tn change during malignant transformation of biliary papillomatosis.

AIM: Biliary papillomatosis is characterized by papillary proliferations of biliary lining cells without invasion or metastasis. The neoplastic character and biological behaviour of this disease remain still speculative. These issues were examined in this study. METHODS AND RESULTS: Mucin core protein MUC1, MUC2, MUC3, MUC5AC and carbohydrate antigens (T, Tn and sialosyl Tn) were immunohistochemically examined, using 11 lesions of biliary papillomatosis from seven patients, and five lesions of biliary papillomatosis with foci of carcinoma from four patients. Five cases of papillary intrahepatic cholangiocarcinoma and 12 histologically normal livers were used as a control. Patients with biliary papillomatosis alone or with carcinoma were middle-aged or elderly (five men and six women). Microscopically, biliary papillomatosis showed a villous, papillo-tubular, papillary, or papillo-villous pattern with a thin fibrovascular core. Cytologically, they were classifiable into biliary epithelial or pyloric gland-like type. The former was frequent in the cases associated with carcinoma. Expression of MUC1, Tn antigen and sialosyl Tn antigen was frequent and marked in biliary papillomatosis alone and with carcinoma and also intrahepatic papillary carcinoma. In addition, marked expression of MUC1 and Tn antigen were rather frequent in biliary papillomatosis with carcinoma and intrahepatic biliary papillary carcinoma compared with biliary papillomatosis. MUC2 was rather frequent and marked in biliary papillomatosis alone compared to other two disease groups. Focal expression of MUC5AC and MUC2 was rather frequent and infrequent irrespective of disease group, respectively. Focal expression of T antigen was frequent in papillary ICC. CONCLUSION: Biliary papillomatosis could undergo overt malignant transformation along with altered phenotypic expression of MUC proteins and mucin carbohydrate antigens.

Aged↗
PubMed2001

Hepatocellular carcinoma arising in non-alcoholic steatohepatitis.

The incidence and significance of hepatocellular carcinoma (HCC) in non-alcoholic steatohepatitis (NASH) has not been previously evaluated in detail. We recently experienced a case of NASH with multicentric HCC in a female patient. At the age of 58 years, the patient was diagnosed with non-insulin-dependent diabetes mellitus, treated by insulin therapy. The patient did not drink alcohol. She was negative for all serological markers of hepatitis B and C virus infection. Because of liver dysfunction, a needle biopsy was performed at the age of 62 years, and pathological findings, such as fatty change, Mallory's body, nuclear glycogen and pericellular fibrosis, suggested a diagnosis of NASH. Subsequently, four nodules were detected in the liver by imaging. Liver biopsies were performed from each nodule. One nodule was pathologically diagnosed as a pseudolymphoma, while three other nodules were moderately differentiated HCC (10 years after the diagnosis of non-alcoholic steatohepatitis), well-differentiated HCC (11 years later) and dysplastic nodule (11 years later), suggesting multicentric occurrence of HCC. This case suggests that HCC could be a late complication of NASH.

Biopsy, Needle↗
PubMed2001

Enhanced expression of basement-membrane-type heparan sulfate proteoglycan in tumor fibro-myxoid stroma of intrahepatic cholangiocarcinoma.

To investigate the molecular mechanism for enhanced fibrous stroma formation in intrahepatic cholangiocarcinoma (ICC), we surveyed the expression pattern of basement-membrane-type heparan sulfate proteoglycan (HSPG; also known as perlecan) at the core protein and the mRNA level in ICC as well as in other liver neoplasms and reactive hepatic diseases. Immunohistochemistry of paraffin-embedded liver sections with hyaluronidase pretreatment showed that HSPG was present in small amounts in normal liver around the bile ducts and the blood vessels within the portal area. There was no evident expression within the hepatic lobules. Intense immunoexpression of HSPG was seen in the tumor-specific fibro-myxoid stroma of ICC and metastatic liver cancer originating from the colon. However, tumor-specific stroma of hepatocellular carcinomas showed little or no expression of HSPG. At the mRNA level, signals for HSPG were found in tumor cells of cholangiocarcinoma and metastatic colonic carcinomas, and in myofibroblasts in the tumor fibro-myxoid-specific stroma. From immunoprecipitation and reverse transcription-polymerase chain reaction (RT-PCR) analyses, a cultured human intrahepatic cholangiocarcinoma cell line (CCKS1), was found to express high levels of HSPG core protein and mRNA. These findings suggest that biliary and metastatic colon carcinoma cells as well as stromal myofibroblasts have a potential for HSPG production. In order to investigate the growth, invasion and metastatic ability of ICC, further study of the 'self-made' stromal component of ICC may provide a new approach.

Adult↗
PubMed2001

Spontaneous occurrence of chronic non-suppurative destructive cholangitis and antimitochondrial autoantibodies in MRL/lpr mice: possible animal model for primary biliary cirrhosis.

MRL/MP mice bearing the lymphoproliferative gene lpr (known as MRL/MP-lpr/lpr or MRL/Ipr mice) are known to spontaneously develop severe autoimmune diseases such as glomerulonephritis, arteritis and arthritis at an early stage of their life. They have also been reported to develop severe sialadenitis, suggesting that this mouse could be a model for Sjögren's syndrome. Primary biliary cirrhosis, an autoimmune disease characterized by chronic non-suppurative destructive cholangitis and the occurrence of antimitochondrial antibodies, is frequently associated with Sjögren's syndrome. In this study, we examined whether cholangitis and/or antimitochondrial antibodies occur in this mouse model, using more than 100 young and old MRL/Ipr mice. We frequently found portal inflammation associated with cholangitis of small intrahepatic bile ducts, especially in older mice. There was also infiltration of inflammatory cells (monocytes) as well as CD4-positive T cells. Epithelioid granuloma and bile-duct loss were also occasionally found. These histological features resemble primary biliary cirrhosis. In addition, antimitochondrial antibodies were shown by immunocytochemistry to be present in the sera of MRL/Ipr mice. There is currently no established animal model for primary biliary cirrhosis. Therefore, further studies on MRL/Ipr mice, with respect to pathogenesis of primary biliary cirrhosis, are warranted.

Animals↗
PubMed2001

A study of mismatch negativity in newborns.

BACKGROUND: Although newborns are presumed to have cognitive ability, studies on the objective cognitive ability of neonates are making little progress. METHODS: We gave auditory and visual stimuli to newborns whose conceptional age ranged from 35 to 43 weeks and recorded the mismatch negativity (MMN) that is said to reflect the process by which stimuli are detected automatically. We compared the waveform and latency of the MMN. RESULTS: The mismatch negativity waveform in newborns was similar to that of adults. The MMN latency tended to shorten with an advance in conceptional age and was especially shortened between 36 and 37 weeks of fetal life. In some newborns whose clinical course indicated a possibility of their having cognitive dysfunction, the MMN latency was prolonged. CONCLUSIONS: Newborns also have cognitive ability and MMN is useful for objectively evaluating the cognitive ability in newborns.

Cognition↗
PubMed2001

Spontaneous labor increases nitric oxide synthesis during the early neonatal period.

BACKGROUND: This paper aimed to assess the influence of spontaneous labor upon endogenous nitric oxide (NO) and endothelin 1 (ET-1) during transition to extrauterine life. METHODS: The serum levels of NO metabolites (the sum of nitrites and nitrates (NOx)) and the plasma level of ET-1 were determined in 53 healthy full-term infants (spontaneous labor group; n=40, cesarean delivery group; n=13). In both groups, blood samples were obtained from a cord vein at birth and from a peripheral vein at 5 days of age. RESULTS: The differences in serum NOx concentrations between the spontaneous labor group and the elective cesarean group were not significant at birth. By the age of 5 days, serum NOx concentrations had risen significantly in the spontaneous labor group to become significantly higher in the elective cesarean group. CONCLUSION: It is speculated that spontaneous labor might enhance endogenous NO synthesis at 5 days of age.

Adaptation, Physiological↗
PubMed2001

Guidelines for catheter intervention in coronary artery lesion in Kawasaki disease.

The Research Committee of Ministry of Health, Labour and Welfare 'Study of treatment and long-term management in Kawasaki disease' reported the guidelines for catheter intervention in coronary artery lesion in Kawasaki disease in this paper. The contents include: (i) background and natural history of coronary artery lesion in Kawasaki disease; (ii) indication of catheter intervention; (iii) types of procedure, and their indication and care; (iv) institute and backup system; (v) the management after procedure, evaluation and follow up; and (vi) prospects, especially in relation to bypass surgery.

Angioplasty, Balloon, Coronary↗
PubMed2001

Expression of endogenous galectin-1 and galectin-3 in intrahepatic cholangiocarcinoma.

Galectins, a family of beta-galactoside-binding animal lectins, might be involved in tumor progression. In this study, the expression patterns of galectin-1 and -3 were examined immunohistochemically in intrahepatic cholangiocarcinoma (ICC), with emphasis on its development and progression as well as its histopathologic features, by use of samples of normal intrahepatic bile duct (n = 20), biliary epithelial dysplasia (n = 15), ICC (n = 40), and a cholangiocarcinoma cell line, CCKS1. In normal intrahepatic bile ducts, galectin-3 was constitutively but weakly expressed, whereas galectin-1 was not expressed. In hepatolithiasis, biliary epithelial dysplasia was strongly positive for galectin-3 but negative for galectin-1. Galectin-3 was frequently and strongly expressed in the cytoplasm of well-differentiated ICCs, and its expression was significantly decreased and less intense or even absent in poorly differentiated ICCs. Galectin-1 was expressed in carcinoma cells in ICC, and its incidence and extent were correlated with histologic dedifferentiation of ICC. Proliferative cell nuclear antigen (PCNA) labeling index (LI) was higher in ICC cases positive for galectin-1 than in those that were negative. Galectin-1 was strongly expressed in cancerous stroma of ICC, and this stromal expression was related to histologic dedifferentiation of ICC. In the carcinoma cell line CCKS1, galectin-1 and -3 were expressed in the cytoplasm of carcinoma cells, and galectin-1 was additionally detected in the culture medium. These results suggest that galectin-1 was newly expressed on carcinoma cells of ICC, and its overexpression seems to be associated with neoplastic progression and proliferative activities, and the expression of galectin-1 in cancerous stroma may also be related to the progression of ICC. Galectin-3 expression in epithelial cells is up-regulated in the preneoplastic and early neoplastic stages of ICC, although galectin-3 tends to disappear at later stages of ICC. HUM PATHOL 32:302-310.

Adult↗
PubMed2001

Molecular identification of bacterial 16S ribosomal RNA gene in liver tissue of primary biliary cirrhosis: is Propionibacterium acnes involved in granuloma formation?

The etiopathogenesis of primary biliary cirrhosis (PBC) remains speculative. Epithelioid granulomas are often found in the vicinity of damaged interlobular bile ducts in PBC, raising the possibility of a reaction to microbial materials. In this study, we tried to detect and identify bacterial DNA within granulomatous lesions in PBC. Using liver sections from 9 patients with PBC and 13 control livers, granuloma in portal tracts, portal tracts without granuloma, and adjacent hepatic parenchyma were selectively microdissected from sections, and then DNA was extracted from them. First, part of the bacterial 16S ribosomal RNA (rRNA) gene was amplified from DNA samples extracted from 5 PBC and 6 control livers, and their amplicons were sequenced for the identification of bacterial species. Several indigenous bacteria were identified. Among them, Propionibacterium acnes (P. acnes) was detected as a major clone in 20% to 50% of sequenced clones from granuloma of PBC, but the detection rate of P. acnes was 0% to 20% in those cloned from adjacent hepatic parenchyma of PBC. Then, a P. acnes-specific PCR was performed using all microdissected samples. Distinct PCR products were identified in epithelioid granuloma in all 9 PBC cases. The result that P. acnes DNA is present as a major clone in granulomas of PBC, suggest that P. acnes is involved in the pathogenesis of granuloma in PBC.

DNA, Bacterial↗
PubMed2001

Human REG I gene is up-regulated in intrahepatic cholangiocarcinoma and its precursor lesions.

The Reg I gene (regenerating gene) and its product (Reg protein) are a regenerating and/or proliferating factor(s) of pancreatic islet cells. The ectopic expression of REG Ialpha was shown in colorectal carcinomas, suggesting that REG Ialpha is related to their carcinogenesis. In this study, we examined the expression of REG I in intrahepatic cholangiocarcinoma (ICC) and its precursor lesion (biliary dysplasia). By polymerase chain reaction and in situ hybridization (ISH) studies using a total of 16 fresh liver specimens, REG Ialpha mRNA was demonstrated in 6 of 11 (55%) ICC cases, but in 0 of 5 (0%) normal livers. Immunohistochemistry for REG I protein was performed in 100 formalin-fixed, paraffin-embedded sections obtained from the 18 cases of ICC alone, 45 hepatolithiasis with ICC (n = 19) or biliary dysplasia (n = 26), 21 hepatolithiasis alone (all with hyperplasia), and 16 normal livers. In ICC, the expression of REG I protein was significantly dependent on the histologic differentiation; 12 of 13 (92%) cases in papillary and well-differentiated, 6 of 16 (38%) cases in moderately differentiated, and 0 of 8 (0%) cases in poorly differentiated types. Moreover, in the lesions of hyperplasia, low-grade dysplasia, and high-grade dysplasia in hepatolithiasis, REG I protein was expressed in 4 of 21 (19%), 7 of 12 (58%), and 13 of 14 (93%) cases, respectively. In normal liver, intrahepatic bile ducts were constantly negative for REG I protein. These findings suggest that neoexpression of REG I is a good marker for biliary mucosa at risk for development of ICC, and also that REG I plays a role in the early stages of biliary carcinogenesis, probably via a cell-proliferative effect.

Bile Duct Neoplasms↗
PubMed2001

Thiazolidinedione- and tumor necrosis factor alpha-induced downregulation of peroxisome proliferator-activated receptor gamma mRNA in differentiated 3T3-L1 adipocytes.

Thiazolidinediones (TZDs) are antidiabetic insulin-sensitizing agents that bind to peroxisome proliferator-activated receptor gamma (PPARgamma) and have potent adipogenic effects on 3T3-L1 preadipocytes. In fully differentiated 3T3-L1 adipocytes, TZDs markedly decreased PPARgamma mRNA levels without reducing the expression of genes that are positively regulated by PPARgamma, such as adipocyte lipid-binding protein 2 (aP2) or lipoprotein lipase-(LPL). PPARgamma mRNA levels were also downregulated by tumor necrosis factor alpha (TNFalpha), an antiadipogenic cytokine. We propose that the downregulation of PPARgamma is not the common denominator of the metabolic effects of TZDs and TNFalpha on mature adipocytes.

3T3 Cells↗
PubMed2001

Effect of angiotensin II on venodilator response to nitroglycerin.

OBJECTIVE: An enhanced circulatory angiotensin II level that results from the administration of nitroglycerin may contribute to the development of nitrate tolerance. Using human hand veins, we investigated whether a subconstricting dose of angiotensin II attenuates the venodilator effect of nitroglycerin, whether pretreatment with losartan influences this effect, and whether angiotensin II also attenuates the venodilator effect of diltiazem. METHODS: In 9 healthy male subjects, increasing doses (0.5-128 ng/min) of nitroglycerin were infused into the dorsal hand vein pretreated with 0 (control), 0.3, or 1 ng/min of angiotensin II. In 8 healthy male subjects, angiotensin II (0.3 and 1 ng/min) was infused into the vein dilated by nitroglycerin with and without pretreatment with losartan and with diltiazem. The diameter of the vein was measured with a linear variable differential transformer. RESULTS: The venodilator response of nitroglycerin was significantly suppressed by the pretreatment with angiotensin II; The maximum venodilator effect was dose-dependently decreased, and the infusion rate producing half-maximum response was dose-dependently increased. The venodilation caused by nitroglycerin was decreased by angiotensin II, and this effect was attenuated by pretreatment with losartan. The venodilation caused by diltiazem was also attenuated by angiotensin II, but this attenuating effect was smaller compared with that caused by nitroglycerin. CONCLUSIONS: These findings suggest that an enhanced angiotensin II level might attenuate the venodilation caused by nitroglycerin and diltiazem, and pretreatment with losartan might decrease the attenuating effect of angiotensin II.

Adult↗
PubMed2001

Furosemide-probenecid interaction as a laboratory exercise for undergraduate education in clinical pharmacology.

OBJECTIVE: The aim of this study was to determine the easiness, reproducibility, and safety of a laboratory exercise for a drug interaction between furosemide and probenecid. METHODS: From 1995 to 1999 approximately 100 medical students participated in the exercise each year after they gave written informed consent. The students were randomly assigned to one of the three groups in a double-blind fashion: group 1, placebo plus 20 mg of furosemide; group 2, 250 mg of probenecid plus 20 mg of furosemide; and group 3, 1000 mg of probenecid plus 20 mg of furosemide. The students took probenecid or its placebo 1 hour before furosemide. Urine volume and urinary sodium excretion were measured for 3 hours after furosemide. At the end of the exercise in 1999, students responded to several questionnaires concerning the utility of furosemide. RESULTS: The entire course of the exercise was completed within half a day. The following findings were obtained every year. (1) Probenecid dose dependently blunted the diuretic effects of furosemide. (2) Time courses of the diuretic effects were altered by probenecid. Ten to twenty percent of the students had slight complaints but completed the exercise without any medications. Finally, more than 80% of the students considered the exercise to be useful. CONCLUSIONS: The data suggest that the exercise of the drug interaction between furosemide and probenecid is easy to perform, reproducible, and safe. Through the experience of the laboratory exercise, students will develop an attitude to assess and estimate potential drug interactions before they prescribe drugs.

Diuresis↗
PubMed2001

Different effects of St John's wort on the pharmacokinetics of simvastatin and pravastatin.

OBJECTIVE: St John's Wort, a widely used herbal product, is an inducer of CYP3A4 and it decreases blood concentrations of CYP3A4 substrates. The effects of St John's Wort on the pharmacokinetics of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors simvastatin (an inactive lactone pro-drug) and pravastatin were determined in this study. METHODS: Sixteen healthy male subjects (n = 8 in group 1 and n = 8 in group 2) took a St John's Wort caplet (300 mg) or matching placebo three times a day for 14 days in a double-blind, crossover study. On day 14, a single oral dose of 10 mg simvastatin and 20 mg pravastatin was given to subjects in group 1 and group 2, respectively. Blood samples were obtained during a 24-hour period after the administration of each drug. RESULTS: Repeated St John's Wort treatment tended to lower plasma simvastatin concentration and significantly (P <.05) lowered concentrations of simvastatin hydroxy acid, its active metabolite. The peak concentration in plasma (ratio, 0.72 of placebo) of simvastatin hydroxy acid tended to be decreased and its area under the plasma concentration-time curve between time zero and 24 hours after administration (ratio, 0.48 of placebo) was significantly decreased (P <.05) by St John's Wort. On the other hand, St John's Wort did not influence plasma pravastatin concentration. No significant differences were observed in the elimination half-life of simvastatin or pravastatin between the placebo and St John's Wort trials. CONCLUSIONS: This study showed that St John's Wort decreases plasma concentrations of simvastatin but not of pravastatin. Because simvastatin is extensively metabolized by CYP3A4 in the intestinal wall and liver, which are induced by St John's Wort, it is likely that this interaction is partly caused by the enhancement of the CYP3A4-mediated first-pass metabolism of simvastatin in the small intestine and liver.

Adult↗