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Biomedical subjects

T Kuroki

Publications and source records attributed to T Kuroki.

At least 73 records · Page 4Linked to original sources
PubMed2000

Laparoscopic microwave coagulation therapy for hepatocellular carcinoma.

BACKGROUND AND STUDY AIMS: Several different effective forms of treatment are available, singly or in combination, for patients with hepatocellular carcinoma (HCC). These include surgical resection, transcatheter arterial embolization, percutaneous ethanol injection, and percutaneous microwave coagulation therapy. In this study, we carried out laparoscopic microwave coagulation therapy (LMCT), using laparoscopic microwave electrodes to treat HCC. PATIENTS AND METHODS: Under local anesthesia, 24 patients with HCCs located on or near the liver surface underwent LMCT under direct laparoscopic vision, with ultrasound guidance. LMCT was performed using microwave electrodes with tips ranging from 15-45 mm in length, and the effectiveness of the treatment was confirmed using contrast-enhanced computed tomography (CT) within two weeks of the LMCT procedure. RESULTS: The mean longest axis of the 26 HCC nodules in 24 patients was 20 mm, and that of the coagulated areas including the nodules was 40 mm, with additional therapy being required in two patients. Complete efficacy of the treatment was observed in 21 patients (87.5%), but local recurrences were seen in three of them one year after LMCT. The three-year survival rate was 92%, but the number of patients included in the study was small. Hemostasis was complete, but mild pneumothorax occurred in three patients. CONCLUSIONS: LMCT under local anesthesia is a minimally invasive and effective therapy when carried out on a single occasion to treat HCCs located near the liver surface, and it can be safely performed under direct visual guidance.

Aged↗
PubMed2000

Assessment of hepatic blood flow by PET with 15O water: correlation between per-rectal portal scintigraphy with 99Tc(m)-pertechnetate and scintigraphy with 99Tc(m)-GSA.

We performed positron emission tomography with 15O water (H2(15)O) to measure hepatic arterial and portal blood flow. In addition, portal haemodynamics and hepatic functional reserve were measured by per-rectal portal scintigraphy and scintigraphy with galactosyl human serum albumin, respectively. We studied 15 patients who had cirrhosis of the liver with underlying viral infection. After the intravenous injection of H2(15)O, positron emission tomography was performed. Blood samples were obtained after beginning the emission scan. The blood samples and positron emission tomographic images were analysed to calculate the radioactivity in the blood and liver. One-compartment model analysis was used to estimate hepatic arterial and portal blood flow. Computer acquisition of gamma-camera data was started just before the injection of 99Tc(m)-galactosyl human serum albumin. A receptor index and an index of blood clearance were calculated on the basis of the radioactivity of the liver and heart. A 99Tc(m)-pertechnetate solution was instilled into the rectum; serial scintigrams were performed and radioactivity curves for the liver and heart were recorded sequentially. A per-rectal portal shunt index was calculated from the curves. Median portal blood flow was 80 ml x 100 g(-1) x min(-1), median hepatic arterial blood flow was 56 ml x 100 g(-1) x min(-1), and median total hepatic blood flow was 138 ml x 100 g(-1) x min(-1) in patients with cirrhosis. The correlations between portal blood flow and the Child-Turcotte classification score, portal shunt index and receptor index were all significant. Our results show that hepatic arterial and portal blood flow can be measured by positron emission tomography with H2(15)O non-invasively and physiologically. This technique may be useful in pathophysiological studies of liver disease.

Hepatitis, Viral, Human↗
PubMed2000

Histological estimation of the efficacy of endoscopic laser coagulation therapy for diffuse antral vascular ectasia.

We present the case of a 72-year-old woman with successful control of repeated episodes of bleeding from diffuse antral vascular ectasia (DAVE) by laser coagulation therapy. In addition to DAVE, the patient also suffered from severe iron deficiency anaemia (due to recurrent bleeding), liver cirrhosis, and huge tumours of hepatocellular carcinoma (HCC). She was referred from another hospital after failure to stop her bleeding episodes. Endoscopic examination revealed diffuse speckled telangiectasia over most of the stomach (from antrum to the upper portion of the body) and large numbers of blood clots. The patient had received repeated blood transfusions, haemostatic drugs, and H2 receptor antagonists at the other hospital, without improvement of the repeated bleeding. She underwent three sessions of endoscopic laser coagulation therapy for the lesions at our hospital after the final diagnosis of DAVE had been made based on the characteristic histological findings of biopsied specimens. This treatment improved her general condition and stopped the bleeding from the gastrointestinal tract even without fasting. Unfortunately, however, her liver function gradually worsened due to HCC and previous massive bleeding, and she finally died of liver failure three months after the last laser session. Autopsied specimens obtained from the patient's stomach revealed that macroscopic diffuse speckled telangiectasia and microscopic typical vasodilatation in mucosal and submucosal layers of gastric tissue had disappeared in the treated areas but not all portions of the DAVE lesion. These histological findings for the treated areas, in addition to the clinical improvement of bleeding, suggest that endoscopic laser coagulation therapy may be useful and one of the first choices in treatment for DAVE.

Aged↗
PubMed2000

Highly selective antibacterial activity of novel alkyl quinolone alkaloids from a Chinese herbal medicine, Gosyuyu (Wu-Chu-Yu), against Helicobacter pylori in vitro.

To elucidate the antibacterial activity of Gosyuyu, the crude extract from the fruit of Evodia rutaecarpa, a Chinese herbal medicine, has been fractionated chromatographically, and each fraction was assayed for antibacterial activity against Helicobacterpylori (H. pylori) in vitro. As the result, a single spot having marked antibacterial activity against H. pylori was obtained and the chemical structure was analyzed. The isolated compound was revealed to be a novel alkyl quinolone alkaloid based on the solubility, IR spectra, NMR analysis and mass spectrometric data after purification by TLC of silica. We compared the antimicrobial activity of this compound with that of other antimicrobial agents and examined susceptibility of various intestinal pathogens. As the result, the new quinolone compounds obtained from Gosyuyu extracts were found to be a mixture of two quinolone alkaloids, 1-methyl-2-[(Z)-8-tridecenyl]-4-(1H)-quinolone and 1-methyl-2-[(Z)-7-tridecenyl]-4-(1H)-quinolone (MW: 339), reported previously. The minimum inhibitory concentration (MIC) of these compounds against reference strains and clinically isolated H. pylori strains were less than 0.05 microg/ml, which was similar to the MIC of amoxicillin and clarithromycin that are used worldwide for the eradication of H. pylori, clinically. Furthermore, it was noted that the antimicrobial activity of these compounds was highly selective against H. pylori and almost non-active against other intestinal pathogens. The above results showed that these alkyl methyl quinolone (AM quinolones) alkaloids were useful for the eradication of H. pylori without affecting other intestinal flora.

Alkaloids↗
PubMed2000

Increased mitogen-activated protein kinase activities stimulated with interleukin-1-beta and mechanism(s) of the kinase signaling pathways in rat gastric epithelial cells.

Interleukin (IL)-1beta, a multifunctional cytokine, is associated with inflammatory gastric mucosa, but the responses of gastric epithelial cells stimulated by IL-1beta are not known. We determined whether IL-1beta activates the two subfamilies of mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinases (ERKs) and c-Jun NH(2)-terminal kinases (JNKs), in rat gastric epithelial cells (RGM1) using in-gel kinase assays. In addition, we examined the mechanism(s) underlying their signaling pathways and the effect on proliferation of these cells. IL-1beta (0-5 x 10(3) pg/ml) dose dependently induced activation of ERKs (p44ERK and p42ERK) and JNKs (p46JNK and p55JNK) in RGM1 cells; maximal activities were attained with 1,000 pg/ml of IL-1beta. These activities were increased with time, and were maximal 20 min after stimulation with IL-1beta (100 pg/ml). Pretreatment with neutralizing antibody against IL-1beta inhibited IL-1beta-induced activation of ERKs and JNKs. Genistein (100 microM), a tyrosine kinase inhibitor, and GF109203X (2 microM), a protein kinase C inhibitor, inhibited the IL-1beta-induced activation of ERKs and JNKs. Six- hour pre-incubation with IL-1beta inhibited proliferation of these cells by 40% at 24 h of incubation, but the inhibition was recovered at 48 h. These findings suggest that IL-1beta activated ERKs and JNKs in rat gastric epithelial cells and inhibited cell proliferation, possibly via the specific receptor for IL-1beta. Activation of MAP kinases by IL-1beta may be mediated by tyrosine kinase and protein kinase C.

Animals↗
PubMed2000

Pentoxifylline accelerates gastric ulcer healing in rats: roles of tumor necrosis factor alpha and neutrophils during the early phase of ulcer healing.

BACKGROUND/AIMS: Pentoxifylline has many anti-inflammatory properties including inhibition of production of tumor necrosis factor alpha (TNF-alpha). Although pentoxifylline prevents several types of gastric mucosal injury, the effect of this drug on ulcer healing is unknown. In this study, we examined the effect of pentoxifylline on healing of acetic acid induced gastric ulcers in rats. METHODS: Rats with gastric ulcer received an intraperitoneal injection of 10 mg/kg pentoxifylline once daily for 14 days or for only the first 7 days or the last 7 days of the 14-day treatment period. Some rats were given antirat neutrophil antiserum intraperitoneally every other day. Ulcer size, myeloperoxidase activity, and concentration and location of TNF-alpha in ulcer tissue were assessed. RESULTS: Administration of pentoxifylline for 14 days or for the first 7 days, but not for the last 7 days, of the 14-day treatment period accelerated ulcer healing. TNF-alpha was detected mainly in monocytes/macrophages and in some neutrophils at ulcer bases and margins. Pentoxifylline markedly decreased the concentration of TNF-alpha as well as the myeloperoxidase activity in ulcer tissue on days 2 and 4. Antirat neutrophil antiserum inhibited neutrophil infiltration into ulcer tissue and accelerated ulcer healing. CONCLUSION: Pentoxifylline accelerates healing of acetic acid induced gastric ulcer in rats. This effect may be due in part to reduction of neutrophil infiltration and inhibition of production of TNF-alpha by inflammatory cells. Early-phase inhibition of inflammatory response may accelerate ulcer healing.

Acetic Acid↗
PubMed2000

Design of a unique PCR primer for detection of oral HPV infection.

Human papillomavirus (HPV) has been known as a pathogen of oral dysplasia. However, suitable PCR primers for the detection of oral HPV infection have not been reported. The aim of this study was to design unique consensus primers. The consensus primers were designed by homologues analyses between subtypes 2, 6, 11, 13, 16, 18, 30, 32 and 58, which frequently infect the oral membrane. PCR, with our designed primer, detected HPV DNA subtypes 2, 6, 11, 16, 18 and 58, and also showed PCR product from a clinical papilloma sample. These results indicate that our designed consensus primer can be used for the study of the relationships between oral disease and HPV infection.

Consensus Sequence↗
PubMed2000

Helicobacter pylori: criminal or innocent bystander?

Most patients with peptic ulcer disease are infected with Helicobacter pylori. However, the infection may not be always causative for the disease. The prevalence of H. pylori infection is about 50% in general. Therefore, half of the patients with peptic ulcer could be infected with this microorganism just by chance. In such cases, H. pylori may do nothing for the ulcer, although it causes chronic active gastritis. This could be the reason for the existence of both H. pylori-positive nonrecurring ulcers and ulcers that recur even after cure of H. pylori infection. H. pylori-positive non-recurring ulcers should be included in non-H. pylori ulcer disease in addition to H. pylori-negative ulcers. NSAIDs are the major cause of H. pylori-negative ulcers, especially H. pylori-negative gastric ulcers. However, more than 10% of ulcers recurred even after cure of H. pylori infection in nonusers of NSAIDs in a 7-year follow-up study. In the same study, 46% of ulcers did not recur in patients in whom eradication of H. pylori failed. There are few (<5%) H. pylori-negative ulcers; about 10% of ulcers recur after cure of H. pylori infection, and about 40% of H. pylori-positive ulcers do not recur. These are all non-H. pylori ulcers, and they represent 30% of all ulcers, which is the general prevalence rate for nonulcer subjects. Therefore, H. pylori may be an innocent bystander in approximately one third of all ulcer patients.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Contribution of hepatitis C virus to the progression of alcoholic liver disease.

BACKGROUND: We determined hepatitis C virus (HCV) antibody, HCV RNA, and genotype in patients with alcoholic liver disease and studied the involvement of HCV in alcoholic liver disease. Additionally, we used the histological activity index (HAI) to study the influence of HCV on the severity of inflammation. METHODS: The subjects were 143 patients with alcoholic liver disease: 7 with fatty liver (FL), 18 with hepatic fibrosis (HF), 24 with alcoholic hepatitis (ALH), 39 with chronic hepatitis (CH), 42 with liver cirrhosis (LC), and 13 with hepatocellular carcinoma (HCC). The HCV RNA positivity rate in each type of disease was 0/7 (0%), 1/18 (6%), 2/24 (8%), 27/39 (69%), 24/42 (57%), and 7/13 (54%), respectively. It was high in the advanced hepatic lesions. RESULTS: Clinically, the serum hepatic function tests after abstinence from drinking improved significantly in the HCV RNA negative patients compared with the positive patients. The proportion of genotype II in each type of disease was 0/0, 0/1 (0%), 1/2 (50%), 18/27 (67%), 18/24 (75%), and 7/7 (100%), respectively. It became high with the advance of pathophysiology. The HCV RNA amount stood at 7.5 +/- 0.4 [log (copies/ml)] in CH, 7.9 +/- 0.4 in LC, and 8.4 +/- 0.8 in HCC, with a statistically significant difference between CH and HCC. However, we found no changes in the HCV RNA amount due to abstinence from drinking. The HAI score was high in the HCV RNA positive patients, but several cases in the HCV RNA negative group showed severe inflammatory changes. Therefore, judging the presence or absence of HCV RNA with the HAI score alone was considered difficult. CONCLUSIONS: These results suggest that HCV, particularly genotype II, plays an important role in the advance of disease to LC and HCC in heavy drinkers.

Adult↗
PubMed2000

[Difference in 201TlCl accumulation mechanism in brain tumors: a comparison of their Na(+)-K+ ATPase activities].

The accumulation levels of 201TlCl and Na(+)-K+ ATPase activity in tumor tissue were compared among glioblastoma, benign glioma and meningioma to study the difference in the mechanism of 201TlCl accumulation. The subjects were 19 cases comprised of 6 glioblastoma, 2 oligodendroglioma, 1 fibrillary astrocytoma, 1 pilocytic astrocytoma and 9 meningioma. Preoperative 201TlCl SPECT was performed in all the cases, and Thallium Index (TL index) was calculated by a ratio of 201TlCl in the tumor area and the contralateral area. In addition, cell membrane was extracted from the tumor tissue collected intraoperatively to determine Na(+)-K+ ATPase activity. No statistically significant difference in TL index was noted between the glioblastoma group (6.97 +/- 2.67) and the meningioma group (5.87 +/- 1.99). This fact showed that there was no difference in the accumulation level of 201TlCl between the two groups. On the other hand, the glioblastoma group indicated a higher value of Na(+)-K+ ATPase activity (49.13 +/- 43.76 mumole/hour/mg protein) than the meningioma group (7.73 +/- 13.84 mumole/hour/mg protein) (p < 0.05, t test). These results suggested the involvement of Na(+)-K+ ATPase activity in 201TlCl accumulation in glioblastoma and the influences of other accumulation mechanism than Na(+)-K+ ATPase activity such as the volume of intratumoral vascular bed in meningioma.

Adult↗
PubMed2000

Structure of lamina propria lymphoid follicles and associated epithelium in the gastric mucosa during Helicobacter pylori infection in ulcer-bearing Mongolian gerbils.

To develop a gerbil model of Helicobacter pylori-induced chronic active gastritis comparable in severity to human lesions, we made acetic acid-induced ulcer in the anterior antral wall and concurrently challenged 1 x 10(8) colony-forming units bacteria per os. At 30 and 60 days after inoculation, the number of viable bacteria colonizing on the surface epithelium of the gastric mucosa was larger in ulcer-bearing animals compared to non-bearing ones. Furthermore, in the former animals, neutrophil and mononuclear cell infiltration as well as lymphoid follicle formation in the lamina propria was more prominent. Electron microscopically, lymphoid follicle-associated epithelium displayed specialized structures. Namely, brush cells interposed between mucous epithelial cells and characterized by prominent microfilament bundles and many apical vesicles or caveola specifically embraced the cluster of intraepithelially invading lymphocytes and macrophage-like cells by the attenuated cytoplasm in an analogous manner to M cells in Peyer's patches. The present study has demonstrated that ulcer formation enhances both H. pylori colonization and lamina propria lymphoid follicle formation and suggested that follicle-associated epithelium might play roles in the delivery of intraluminal antigen.

Animals↗
PubMed2000

[Microtia: a new chronology for the total external ear reconstruction. A retrospective study of eight cases].

After 14 months of personal training with Professor Ichinose's team in Chiba (Japan), the author reports a new chronology of the total external ear reconstruction for microtia. This approach, proposed by Dr Yoshimoto, subtracts in time spent on creating the cartilaginous framework from the total general anesthesia time. The principles of this technique and its chronology are described. The results of eight patients operated according to this method between February 1994 and October 1999 are analyzed and compared to the 35 previous reconstructions performed by this team. The advantage of this chronology has been established: this method allows a considerable reduction of the general anesthesia time, a rationalization of the cost of these reconstructions, an increased comfort for the patients and an easier learning process for young plastic surgeons.

Cartilage↗