Biomedical subjects

T Kiba

Publications and source records attributed to T Kiba.

At least 19 recordsLinked to original sources

PubMed2001

Expression of apoptosis on rat liver by hepatic vagus hyperactivity after ventromedial hypothalamic lesioning.

We examined whether the Fas (APO-1/CD95)/Fas ligand system mediates apoptosis in rats with ventromedial hypothalamus (VMH) lesions. Northern and Western blotting indicated that VMH lesions lead to a significant increase in Fas mRNA and protein expression from day 1 to day 7 and in Fas ligand mRNA and protein expression from day 2 to day 7. Immunohistochemistry indicated that the region of strongest Fas expression shifted from acinar zone 1 to zones 2 and 3 by day 7 after VMH lesioning and that at days 2-7 Fas-ligand-positive hepatocyte cell membranes and cytoplasm were randomly distributed in acinar zones 1-3. We also analyzed activation of caspase 3-like proteases in hepatocytes, Kupffer cells, and sinusoidal endothelial cells. Spectrofluorometric assay demonstrated that caspase 3-like activity significantly increased only in hepatocytes after VMH lesioning. Moreover, electron microscopy and TUNEL assay showed that VMH lesions induced apoptosis. All of these effects were completely inhibited by hepatic vagotomy and administration of atropine. Vagal firing after VMH lesioning may stimulate Fas/Fas ligand system-mediated apoptosis through the cholinergic system in the rat liver.

Alanine Transaminase↗

PubMed2001

Using contrast-enhanced sonography to assess the effectiveness of transcatheter arterial embolization for hepatocellular carcinoma.

OBJECTIVE: We evaluated the usefulness of contrast-enhanced wideband harmonic gray-scale sonography in assessing the therapeutic effects of transcatheter arterial embolization for patients with hepatocellular carcinoma and compared the findings of this imaging modality with those of helical CT. SUBJECTS AND METHODS: Twenty-nine patients with 39 hepatocellular carcinoma lesions were examined. We scanned lesions before and after therapy using contrast-enhanced wideband harmonic gray-scale sonography after injection of a galactose-palmitic acid contrast agent. All patients held their breath for 20--50 sec after injection while the vascularity of the tumor was observed. We then monitored tumor enhancement between 60 and 180 sec after injection with patients breath-holding for a few seconds. Lesions were considered to exhibit viable tumor residue if hypervascular enhancement was observed in the tumor. We compared this enhancement with helical CT findings. RESULTS: After therapy, 36 of the 39 lesions showed viable tumor residue on contrast-enhanced wideband harmonic gray-scale sonography, with no artifacts from iodized oil. Helical CT revealed a high-attenuation area in 12 of the 36 lesions, whereas 24 of the 36 lesions could not be evaluated for tumor residue as a result of artifacts from iodized oil accumulation in the tumor. The remaining three lesions showed complete deposition of iodized oil and complete necrosis on contrast-enhanced wideband harmonic gray-scale sonography. CONCLUSION: Contrast-enhanced wideband harmonic gray-scale sonography is useful in evaluating the therapeutic effects of transcatheter arterial embolization for hepatocellular carcinoma.

Aged↗

PubMed2001

Nonresectable hepatocellular carcinoma: improved percutaneous ethanol injection therapy guided by CO(2)-enhanced sonography.

OBJECTIVE: The purpose of our study was to evaluate the usefulness of percutaneous ethanol installation using CO(2)-enhanced sonography for patients with nonresectable hepatocellular carcinoma (HCC). SUBJECTS AND METHODS: Forty-six patients with 65 HCC lesions were examined with contrast-enhanced sonography with direct injection of CO(2) into the proper hepatic artery during arteriography. We performed percutaneous ethanol injection guided by CO(2)-enhanced sonography for the treatment of hypervascular HCC lesions that could not be treated with conventional percutaneous ethanol injection or with transcatheter arterial embolization. RESULTS: CO(2)-enhanced sonography detected five additional small HCC lesions before treatment (p<0.05) and 14 new lesions during follow-up (p<0.01), than conventional sonography detected. CO(2)-enhanced sonography showed positive enhancement of residual lesions after initial treatment (n = 3) and incomplete local treatment (n = 5) that were not detected on conventional sonography. These 27 lesions were successfully treated with percutaneous ethanol injection using a mixture of iodized oil and ethanol and guided by CO(2)-enhanced sonography. CONCLUSION: CO(2)-enhanced sonography is a sensitive method for detecting residual viable lesions and small new HCC lesions that cannot be detected with conventional sonography. Percutaneous ethanol injection guided by CO(2)-enhanced sonography can treat hypervascular HCC lesions that cannot be treated with conventional percutaneous ethanol injection or transcatheter arterial embolization.

Adult↗

PubMed2001

Contrast-enhanced, wide-band harmonic gray scale imaging of hepatocellular carcinoma: correlation with helical computed tomographic findings.

We evaluated the usefulness of contrast-enhanced, wide-band harmonic gray scale imaging for the diagnosis of hepatocellular carcinoma and compared it with helical computed tomography. Forty-eight patients with 61 hepatocellular carcinoma lesions were scanned by contrast-enhanced, wide-band harmonic gray scale imaging after an intravenous bolus injection of the contrast agent Levovist. Fifty-seven of the 61 hepatocellular carcinoma lesions showed hypervascular enhancement, and intratumoral vessels could be observed in 40 of the 57 lesions. Helical computed tomography revealed a high-attenuation area in 54 of the 61 lesions, whereas the other lesions showed an equivocal-attenuation area. Contrast-enhanced, wide-band harmonic gray scale imaging is a useful method for diagnosing the vascularity of hepatocellular carcinoma.

Adult↗

PubMed2000

Sonographically guided core-needle biopsy of focal splenic lesions: report of four cases.

There are few published reports about the use of splenic needle biopsies in the investigation of focal splenic lesions. We report our experience with sonographically guided core-needle biopsies of splenic lesions in 4 patients. The biopsies resulted in the following diagnoses: sarcoidosis, malignant lymphoma, infarction, and scar tissue. Surgery was avoided in the 3 patients diagnosed with sarcoidosis, infarction, and scar tissue by ruling out the possibility of a malignant splenic tumor. None of the patients experienced significant complications. We conclude that splenic core-needle biopsy is a useful and safe diagnostic tool for the evaluation of focal splenic lesions.

Adult↗

PubMed2000

Fas (APO-1/CD95) mRNA is down-regulated in liver regeneration after hepatectomy in rats.

The interaction of Fas (APO-1/CD95) and the Fas ligand system induces apoptosis. However, the role of the Fas/Fas ligand system in normal physiological liver cell death remains to be determined. Using northern blotting analysis, we investigated the role of Fas and Fas ligand mRNA expression in liver regeneration in rats until 14 days after partial hepatectomy. Partial hepatectomy led to a significant decrease in Fas mRNA levels at 2 h, with a further gradual reduction until 18 h. The minimum Fas mRNA levels persisted until 5 days after the surgery. Fas mRNA levels then increased markedly at 6 days, and gradually increased to the initial levels by 14 days after the surgery. However, partial hepatectomy did not affect the expression of Fas ligand mRNA levels. These findings suggest that Fas mRNA is down-regulated in liver regeneration after partial hepatectomy, and that when the original liver mass is gradually regenerating, Fas mRNA is again up-regulated to the initial levels.

Animals↗

PubMed2000

Detection of vascular endothelial growth factor and its receptor expression in human hepatocellular carcinoma biopsy specimens.

BACKGROUND: Vascular endothelial growth factor (VEGF) exerts its actions on the microvasculature, by interacting with specific endothelial cell receptors, and thus, contributes to angiogenesis and growth in many tumours. METHODS: Using nested reverse-transcription-polymerase chain reaction, we examined the biopsy specimens of 14 patients with human hepatocellular carcinoma (HCC) and cirrhosis, for the expression of hepatic VEGF, and the VEGF receptors KDR and fit-1. To avoid the influence of hypoxia or ischaemia induced by surgical manipulation, we used biopsy specimens of the liver instead of resected specimens. RESULTS: Vascular endothelial growth factor mRNA expression was detected in the tumour portion of the specimens in 13 of 14 patients (93%), and in the corresponding non-tumour portion of the specimens in eight patients (57%; P= 0.08). No differences were found between the tumour portion and the corresponding non-tumour portion in relative concentrations of VEGF mRNA. However, mRNA expression of the VEGF receptors, KDR and fit-1, was detected in 14 (100%) and 11 (79%) of the tumour portions, respectively, and in four (29%) and five (36%) of the corresponding non-tumour portions, respectively (chi2 test: KDR, P< 0.01; fit-1, P= 0.08). The relative concentration of KDR mRNA in the tumour portions was significantly higher than in the non-tumour portions (Mann-Whitney U-test: P<0.001) but no differences were detected for fit-1. CONCLUSIONS: KDR mRNA is significantly overexpressed in HCC lesions and could be associated with the angiogenesis and tumour growth induced by VEGF.

Aged↗

PubMed2000

Genes encoding pseudo-response regulators: insight into His-to-Asp phosphorelay and circadian rhythm in Arabidopsis thaliana.

In the higher plant, Arabidopsis thaliana, results from recent intensive studies suggested that His-to-Asp phosphorelay mechanisms are involved presumably in propagation of environmental stimuli, such as phytohormones (e.g. ethylene and cytokinin). Here we identified and characterized a set of novel Arabidopsis genes whose products considerably resemble the authentic response regulators (ARR-series) of Arabidopsis in the sense that they have a phospho-accepting receiver-like domain. However, they should be discriminated from the classical ones in the strict sense that they lack the invariant phospho-accepting aspartate site. They were thus named APRRs (Arabidopsis pseudo-response regulators). Two such representatives, APRR1 and APRR2, were characterized extensively through cloning of the corresponding cDNAs, in terms of their structural designs, biochemical properties, subcellular localization in plant cells, and expression profiles at the transcriptional level. The result of in vitro phosphorylation experiment with the Arabidopsis AHP phosphotransmitter suggested that the pseudo-receivers have no ability to undergo phosphorylation. The result of transient expression assay with onion epidermal cells showed that the GFP-APRR1 fusion protein has an ability to enter into the nuclei. The C-terminal domain of APRR1, termed CONSTANS-motif, appears to be responsible for the nuclear-localization. The most intriguing result was that the accumulation of APRR1 transcript is subjected to a circadian rhythm. The APRR1 protein is identical to the one that was recently suggested to interact with the ABI3 (ABISCISIC ACID INSENSITIVE3) protein. These are discussed with special reference to the His-to-Asp phosphorelay signal transduction and circadian rhythm in Arabidopsis thaliana.

Amino Acid Sequence↗

PubMed2000

Color Doppler sonography for evaluating response to transcatheter arterial embolization and percutaneous ethanol injection therapy and for detecting recurrence of hepatocellular carcinoma.

Eighty-six patients (mean age, 63 years) with 92 hepatocellular carcinomas (2.0 cm or greater in diameter; mean +/- SD, 3.5 +/- 1.6 cm) underwent color Doppler sonography before and after transcatheter arterial embolization and after subsequent percutaneous ethanol injection for (1) identification of pulsatile flow in the residual tumor area after transcatheter arterial embolization, (2) evaluation of therapeutic effectiveness of combined transcatheter arterial embolization and percutaneous ethanol injection, and (3) detection of recurrence during follow-up evaluation. Before and 2 weeks after transcatheter arterial embolization, color Doppler sonography revealed pulsatile flow in 76 (82.6%) and 43 (46.7%)lesions, respectively. After percutaneous ethanol injection, tumor stains in these lesions completely disappeared on digital subtraction angiography (gold standard). During follow-up study (3 to 45 months), digital subtraction angiography revealed recurrence in 73 patients (38 local recurrences and 19 new lesions [2.0 cm or greater]), whereas color Doppler sonography revealed pulsatile flow in 76.3% (local) and 63.2% (new) (not significant). Color Doppler sonography was useful for complying with our three objectives, especially for detecting local recurrence during follow-up evaluation.

Aged↗

PubMed1999

Expression of interferon receptor genes in the liver as a predictor of interferon response in patients with chronic hepatitis C.

Interferon (IFN) receptor mRNA expression patterns in the liver have been shown to correlate with the effectiveness of IFN therapy in patients with hepatitis C virus (HCV) infection. However, it is not clear to what extent this factor contributes to the short (primary)- and long (sustained)-term results of IFN treatment with respect to biochemical and virological remission. Eighty-two patients who subsequently received lymphoblastoid IFN-alpha therapy underwent liver biopsies before IFN therapy. Possible factors that might correlate with IFN response were chosen and analyzed. The primary biochemical and virological responses at the end to treatment (24 weeks) were 63% and 43% vs. 46% and 32% for sustained biochemical and virological remission at the end of follow-up (48 weeks), respectively. In univariate analysis, the absence of HCV genotype 1b, a low titer of HCV RNA, and the expression of IFN receptor mRNA were significantly correlated with sustained biochemical and virological responses to IFN therapy. Multiple logistic regression analysis showed that IFN receptor mRNA expression and the absence of genotype 1b were significant predictors of the sustained biochemical and virological effectiveness of IFN therapy. IFN receptor mRNA expression predicted a sustained virological response to IFN therapy with a positive predictive value of 100% with genotype non-1b and had a negative predictive value of 97% with genotype 1b. It is concluded that expression of IFN receptor genes in the liver is a useful index for predicting the short- and long-term efficacy of IFN therapy in patients with chronic HCV infection.

Alanine Transaminase↗

PubMed1999

Hepatic arterial resistance after mixed-meal ingestion in healthy subjects and patients with chronic liver disease.

PURPOSE: This study investigated hemodynamic changes in the resistance index of the hepatic artery after mixed-meal ingestion. METHODS: We used color Doppler sonography to measure hemodynamic changes in the right hepatic artery in response to mixed-meal ingestion (225 ml, 69 g, 300 kcal) in 9 healthy subjects, 15 patients with chronic hepatitis with low-grade fibrosis (no bridging), 10 patients with chronic hepatitis with moderate-grade (bridging) fibrosis, and 18 patients with cirrhosis. RESULTS: After mixed-meal ingestion, the mean (+/-standard error) maximum increase in the resistance index of the right hepatic artery in healthy subjects was 31+/-2%. These changes were significantly greater than those in patients with chronic hepatitis with low-grade fibrosis (22+/-2%; p<0.05), patients with chronic hepatitis with moderate-grade fibrosis (11+/-2%; p<0.01), and cirrhotic patients (5+/-2%; p<0.01). Mixed-meal ingestion produced significantly smaller increases in the resistance index in cirrhotic patients than in patients with chronic hepatitis with low-grade fibrosis (p<0.01). A postprandial increase in the resistance index of 15% or less was associated with 100% sensitivity, 72% specificity, and 84% accuracy in distinguishing patients with cirrhosis from patients with chronic hepatitis. CONCLUSIONS: The response of the resistance index after mixed-meal ingestion decreases as the severity of hepatic fibrosis increases. Doppler evaluation of postprandial increases in the resistance index of the right hepatic artery may be useful in differentiating between patients with chronic hepatitis and those with cirrhosis.

Chronic Disease↗

PubMed1999

Dehydroepiandrosterone (DHEA) facilitates liver regeneration after partial hepatectomy in rats.

In this study we investigated whether or not liver regeneration is facilitated by dehydroepiandrosterone (DHEA) after partial (70%) hepatectomy in rats. Treatment with DHEA (300 mg/kg body weight) did not cause any significant increase in the expression ratio of proliferating cell nuclear antigen (PCNA) in sham-operated controls; however, in partially hepatectomized rats it caused a significant increase in the ratio in hepatocytes 24 and 36 hr after hepatectomy. In partially hepatectomized rats, DHEA treatment significantly accelerated the restoration of liver 48, 60, and 72 hr after partial hepatectomy. The restoration rate in DHEA-treated hepatectomized rats at 72 hr was 1.3-fold greater than in partially hepatectomized controls. Treatment with androstenedione (300 mg/kg body weight), the first metabolite of DHEA, did not cause any significant increase in the expression of PCNA in either sham-operated controls or partially hepatectomized rats. These results indicate that DHEA itself promotes the liver regenerative process after partial hepatectomy in rats.

Androstenedione↗

PubMed1999

Correlation between hepatic tumor index on color Doppler sonography and tumor vessels on arteriography in large hepatocellular carcinomas.

We assessed a possible correlation between the hepatic tumor index (as the ratio of the tumoral peak systolic velocity to the peak systolic velocity of the right or left hepatic artery) and grade of tumor vessel in large hepatocellular carcinomas (HCCs). Color Doppler sonographic findings were evaluated and compared with selective hepatic arteriographic findings in 78 patients with 93 hepatocellular carcinomas larger than 2.0 cm in diameter. Pulsatile color flow images were obtained in 78 of 93 lesions. The hepatic tumor index was equal to or greater than 1.0 in 57 of 78 lesions. These lesions were revealed arteriographically to have distinct tumor vessels and/or arteriovenous shunting. When this index was 1.0 or greater, we calculated 90% accuracy in distinguishing HCCs with distinct tumor vessels from those without distinct tumor vessels. The hepatic tumor index correlated with the grade of tumor vessels and the presence of arteriovenous shunting.

Adult↗

PubMed1999

Compilation and characterization of Arabidopsis thaliana response regulators implicated in His-Asp phosphorelay signal transduction.

His-Asp phosphorelays are evolutionary-conserved powerful biological tactics for intracellular signal transduction. Such a phosphorelay is generally made up of "sensor histidine (His)-kinases", "response regulators", and "histidine-containing (HPt) phosphotransmitters". In the higher plant, Arabidopsis thaliana, results from recent intensive studies suggested that His-Asp phosphorelays may be widely used for propagating environmental stimuli, such as phytohormones (e.g., ethylene and cytokinin). In this study, we first inspected extensively the occurrence of Arabidopsis response regulators in order to compile and characterize them. The results showed that this higher plant has, at least, 14 members of the family of response regulators that can be classified into two distinct subtypes (type-A and type-B), as judged from their structural designs, biochemical properties, and expression profiles. Comparative studies were conducted for each representative (ARR3 and ARR4 for type-A, and ARR10 for type-B). It was suggested that expression of the type-A response regulator is cytokinin-inducible, while that of the type-B response regulator appears to be not. Results from yeast two-hybrid analyses suggested that the type-B response regulator may have an ability to stably interact with a set of HPt phosphotransmitters (AHPs). These and other results will be discussed with special reference to the His-Asp phosphorelay signaling network in Arabidopsis thaliana.

Amino Acid Sequence↗

PubMed1999

Differential expression of genes for response regulators in response to cytokinins and nitrate in Arabidopsis thaliana.

In Arabidopsis thaliana, a number of response regulators are presumably involved in His-Asp phosphorelay signal transduction in response to environmental stimuli, such as phytohormones. Previously, it was shown that expression of a certain set of genes for response regulators are cytokinin- and nitrate-responsive in their mRNA accumulation, under certain growth conditions [Taniguchi et al. (1998) FEBS Lett. 429: 259, Brandstatter and Kieber (1998) Plant Cell 10: 1009]. To answer the critical question of whether or not other response regulator genes, so far identified in Arabidopsis thaliana, are also cytokinin-inducible, here an extended comparative examination was carried out. It was demonstrated that not all of response regulator genes are necessarily cytokinin-responsive in their transcription. Rather, the members of a certain subfamily (type-A) are cytokinin-responsive, but those belonging to the other (type-B) are not. The presumed nitrate-responsiveness was also assessed for the same set of response regulators, and the analogous view was supported. These results suggest that the two subtypes of response regulators differ from each other, as judged from not only their structural designs, but also the expression profiles of their transcripts in response to plant stimuli.

Arabidopsis↗

PubMed1999

Medullary thyroid carcinoma with multiple hepatic metastases: treatment with transcatheter arterial embolization and percutaneous ethanol injection.

A 54-year-old man with medullary thyroid carcinoma in the thyroid gland was unable to undergo total thyroidectomy because the tumor had invaded the mediastinum. Radiation therapy and chemotherapy were given. Seven years later, intractable diarrhea and abdominal pain appeared, and computed tomography demonstrated hypervascular tumors in the thyroid gland and in the liver. The tumors were successfully treated with percutaneous ethanol injection to a lesion in the thyroid gland and transcatheter arterial embolization followed by percutaneous ethanol injection to tumors in the liver. Transcatheter arterial embolization and percutaneous ethanol injection may be valuable in treating medullary thyroid carcinoma.

Angiography↗

PubMed1998

Expression of Arabidopsis response regulator homologs is induced by cytokinins and nitrate.

We examined cytokinin and nitrate responsiveness in gene expression of five distinct response regulator homologs (ARR3-ARR7) in the leaves of nitrogen-starved Arabidopsis plants. The transcripts accumulated after spraying the shoots with t-zeatin. The induction of accumulation was highly specific for cytokinins. The transcripts also accumulated by supply of nitrate to the culture medium. These findings suggest that ARRs are involved in inorganic nitrogen signal transduction mediated by cytokinin as in the case of ZmCip1, a response regulator homolog recently identified in maize.

Arabidopsis↗

PubMed1998

The long term efficacy of combined transcatheter arterial embolization and percutaneous ethanol injection in the treatment of patients with large hepatocellular carcinoma and cirrhosis.

BACKGROUND: The long term efficacy of combination therapy with transcatheter arterial embolization (TAE) followed by percutaneous ethanol injection (PEI) was studied in patients with large primary hepatocellular carcinoma (HCC) tumors and cirrhosis. METHODS: The series included 83 patients with large unresectable HCC lesions, the largest of which was greater than 3 cm in largest dimension. Fifty-five had a solitary lesion and 28 had multiple (2 or 3) lesions. All patients were treated with both TAE and PEI and their survival rates were determined. RESULTS: The 3-, 5-, and 7-year calculated survival rates for the patients were be 68%, 35%, and 14%, respectively. The number of lesions (solitary vs. multiple), the stage of cirrhosis (Child's Class A vs. Class B or C), and the size of the largest lesion (3-5 cm in largest dimension compared with > 5 cm) significantly affected the survival rate (P < 0.05 to P < 0.01, log rank test). The 3-, 5-, and 7-year survival rates of the Child's Class A patients who had a 3-5 cm solitary lesion (n = 22) were 100%, 75%, and 27%, respectively. The Cox proportional hazards model showed the stage of cirrhosis and size of the largest lesion to be independently associated with survival. No serious complications occurred during or after treatment. CONCLUSIONS: Combination therapy with TAE and PEI is an effective and safe treatment that may improve the long term survival of patients with cirrhosis associated with large HCC lesions, and survival after this combination therapy may be comparable to that after surgery.

Adult↗