Biomedical subjects

K Kubota

Publications and source records attributed to K Kubota.

At least 73 records · Page 4Linked to original sources

PubMed2001

Bochodalek hernia in a young adult: report of a case.

A Bochodalek hernia is rarely seen in adults. An 18-year-old man was referred to our institute with the chief complaint of a sudden onset of left subcostal pain, nausea, and vomiting. A radiograph and a computed tomographic scan of the chest revealed a Bochodalek hernia. Emergency surgery was thus performed. The herniated organs were put back into the peritoneal cavity and the hernial hilum was closed. The postoperative course was uneventful. A routine chest radiograph 1 month before had shown a slight elevation of the left hemidiaphragm and further examination using computed tomography suggested a Bochodalek hernia, but he had merely been followed up since there were no symptoms. As soon as a diagnosis is made, specific repairs should be carried out even if no symptoms are present, to prevent such complications as strangulation or perforation.

Adolescent↗

PubMed2001

Telomerase activity as a predictive marker for recurrence of hepatocellular carcinoma after hepatectomy.

BACKGROUND: Expression of telomerase activity and stabilization of telomeres are concomitant with attainment of immortality in tumor cells. Telomerase activity levels in hepatocellular carcinoma (HCC) may serve as a predictive marker for recurrence after surgery. METHODS: Telomerase activity levels in HCC were measured in 37 patients undergoing hepatectomy by the telomeric repeat amplification protocol. The clinicopathologic factors and telomerase activity were analyzed to identify factors that were important in affecting recurrence of HCC and recurrence-free survival. RESULTS: Telomerase activity was detected in 23 patients (62.2%), and was not significantly associated with seven other HCC-related factors. After a median follow-up of 34 months, 24 patients (64.9%) had recurrence of HCC. In univariate analyses, telomerase activity of more than 20 total product generated (TPG) and portal vein invasion were found to be significantly related to a shorter time to recurrence. Multivariate analysis demonstrated that telomerase activity (>20 TPG) was significantly related to an increased risk of recurrence (relative risk 2.36, 95% confidence interval 1.03 to 5.43, P = 0.04). CONCLUSIONS: Telomerase activity can be identified as an independent predictor for recurrence after resection of HCC.

Adult↗

PubMed2001

Neural substrates for recognition of familiar voices: a PET study.

Identification of familiar people is essential in our social life. We can identify familiar people by hearing their voices as well as by viewing their faces. By measuring regional cerebral blood flow (rCBF) by positron emission tomography (PET), we identified neural substrates for the recognition of familiar voices. The brain activity during discrimination of voices of the subjects' associates and friends from those of unfamiliar people was compared with that during an analogous discrimination of their own voice from unfamiliar voices as well as during vowel discrimination. The left frontal pole, right temporal pole, right entorhinal cortex, and left precuneus were activated to a greater extent during discrimination of familiar voice than during control discriminations, suggesting that these brain regions are involved in the recognition of familiar voices. Furthermore, the adjusted values of rCBF in the left frontal pole and right temporal pole correlated with the number of subjects' correct identification of familiar voices. The present results suggest that these two regions are coactively associated with matching the currently heard voice to familiar voices in one's memory.

Adult↗

PubMed2001

Serum levels of KL-6 are useful biomarkers for severe radiation pneumonitis.

The antigen KL-6, a mucin-like high-molecular-weight glycoprotein, is expressed on type-2 pneumocytes and bronchiolar epithelial cells. Serum levels of KL-6 have been shown to correlate well with the activities of several different kinds of interstitial pneumonia. The purpose of this study was to assess the usefulness of monitoring serum KL-6 levels in patients who had received thoracic radiotherapy (TRT). In particular, the usefulness of such a protocol for the early diagnosis of severe radiation pneumonitis (RP) and the evaluation of its progress and severity was examined. Serum KL-6 levels were retrospectively monitored in 16 patients with lung cancer who had received TRT with or without chemotherapy. Eight of these patients had developed severe RP and eight had developed localized (within the irradiated field) RP. Serum KL-6 levels were measured using a modified sandwich-type enzyme-linked immunosorbent assay. In patients who developed severe RP, serum KL-6 levels showed a consistent tendency to increase after the clinical diagnosis of RP. In four patients, serum KL-6 levels even began to rise before a clinical diagnosis of severe RP had been made. In the patients with localized RP, on the other hand, the serum levels did not show any tendency to increase during or after TRT. Moreover, patients whose serum KL-6 levels rose more than 1.5 times higher than their pre-treatment serum KL-6 level, had a large chance of developing severe RP that was unresponsive to steroid hormones and resulted in death. Serum KL-6 levels, therefore, should be useful indicators for the early diagnosis of severe RP and for estimating its progress and severity in patients treated with TRT.

Aged↗

PubMed2001

Inflammatory solitary iliac artery aneurysms: a report of two cases.

Inflammatory abdominal aortic aneurysms are associated with atherosclerosis, which are characterized by specific clinical manifestation. We treated two patients with unilateral solitary iliac artery aneurysms with perianeurysmal fibrosis which compressed the ureter resulting in ipsilateral hydronephrosis. After the iliac artery aneurysm was repaired with a prosthetic graft, the hydronephrosis resolved. Microscopically, there was clear evidence of atherosclerosis in one case. There was a characteristic inflammatory reaction around the adventitia in both aneurysms. Localized iliac perianeurysmal fibrosis has not been particularly described. The clinicopathologic similarities between these cases and inflammatory abdominal aortic aneurysms suggest the same pathogenesis.

Aged↗

PubMed2001

Analysis of glycosidically bound aroma precursors in tea leaves. 2. Changes in glycoside contents and glycosidase activities in tea leaves during the black tea manufacturing process.

Glycosides are known to be precursors of the alcoholic aroma compounds of black tea. They are hydrolyzed by endogenous glycosidases during the manufacturing process. Changes in the amounts of these glycosides during the manufacturing process were investigated by using a capillary gas chromatographic--mass spectrometric analysis after trifluoroacetyl derivatization of the tea glycosidic fractions. Primeverosides were 3-fold more abundant than glucosides in fresh leaves, but they decreased greatly during the manufacturing process, especially during the stage of rolling. After the final stage of fermentation, primeverosides had almost disappeared, whereas glucosides were substantially unchanged. These results show that hydrolysis of the glycosides mainly occurred during the stage of rolling and confirm that primeverosides are the main black tea aroma precursors. This was also supported by the changes in the glycosidase activities in tea leaves. The glycosidase activities remained at a high level during withering but decreased drastically after rolling.

Fermentation↗

PubMed2001

Formation by mechanical stimulus of the flavor compounds in young leaves of Japanese pepper (Xanthoxylum piperitum DC.).

The volatile compounds formed in slapped and crushed young leaves of Japanese pepper (Xanthoxylum piperitum DC.) were compared with those of intact leaves by using a dynamic headspace gas analysis combined with GC-MS in an on-line system, together with the results of a sensory evaluation. The results indicated that the factors influencing the aroma note were mainly the constituent oxygenated monoterpenes and C(6) compounds and the quantity of terpene hydrocarbons. To clarify the formation mechanism for the aroma, the activities of lipoxygenase and beta-D-glucosidase were investigated. The results revealed that the hydrolysis of glycosides and the degradation of unsaturated fatty acids both played an important role in the formation of the major aroma compounds in young leaves of Japanese pepper.

Humans↗

PubMed2001

Analysis of glycosidically bound aroma precursors in tea leaves. 3. Change in the glycoside content of tea leaves during the oolong tea manufacturing process.

A direct qualitative and quantitative determination of the glycosides of tea aroma compounds at the four stages of the oolong tea manufacturing process (plucking, solar withering, indoor withering, and oolong tea product) was carried out by a capillary gas chromatographic-mass spectrometric analysis after trifluoroacetyl derivatization of the glycosidic fractions. Sixteen glucosides and primeverosides were identified and quantified in cv. Chin-shin-oolong and cv. Chinhsuan-oolong. A comparison of the glycosides in dried fresh leaves between the two cultivars showed significant differences. During the manufacturing process, the amounts of most of these glycosides increased from the solar-withering stage, reaching the highest level at the final stage of oolong tea production. It was noted that no glycoside decreased in its content during the manufacturing process, this being quite different from the manufacture of black tea. In addition, the contents of these alcoholic aroma compounds in the free aroma concentrate from each cultivar remained almost unchanged or slightly decreased, and they constituted only about 12 and 17% in amount of the whole oolong tea aroma compounds. However, jasmine lactone and indole were markedly higher in the final oolong tea products.

Chromatography, Gas↗

PubMed2001

Geraniol dehydrogenase activity related to aroma formation in ginger (Zingiber officinale Roscoe).

Geranial is one of the potent odor compounds in fresh ginger. To clarify the generation of geranial in ginger, the alcohol dehydrogenase activity was measured in a crude enzymatic system of ginger. This enzyme solution was found to contain geraniol dehydrogenase (GeDH) specifically acting on geraniol as a substrate with NADP as a coenzyme. Geranial generation and GeDH activity were investigated for different maturity stages and storage periods of ginger. Both were at maximum levels from just after harvesting to initial storage. The GeDH activity subsequently dropped, and the generation of geranial also stopped. These results suggest that the GeDH activity in ginger is related to the generation of geranial.

Acyclic Monoterpenes↗

PubMed2001

Isolation of some glycosides as aroma precursors in young leaves of Japanese pepper (Xanthoxylum piperitum DC.).

To clarify the formation mechanism for the major alcoholic aroma compounds in young leaves of Japanese pepper, the glycosides were isolated as aroma precursors. The presence of glycosides of the main alcoholic aroma constituents was indirectly determined by enzymatic hydrolysis and trifluoroacetylation (TFA) of the glycoside-containing fraction. After Amberlite XAD-2 column chromatography, ODS flash chromatography, and high-performance liquid chromatography (HPLC), two new compounds, namely, (3S,6S)-cis-linalool-3,7-oxide beta-D-glucopyranoside and 2-methylpropanyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, were isolated. In addition, (3S,6R)-cis-linalool-3,6-oxide beta-D-glucopyranoside, which absolute configuration was the first determined, and six known glycosides, citronellyl beta-D-glucopyranoside, linalyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, (Z)-3-hexenyl beta-D-glucopyranoside, benzyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside, dendranthemoside A, and 3,6-dihydroxy-5,6-dihydro-beta-ionol 9-beta-D-glucopyranoside, were isolated. All of these glycosides were isolated for the first time from the leaves of Japanese pepper. Their structures were established on the basis of spectral data and chemical evidence. The ratios of stereoisomers of the aglycon moieties of citronellyl beta-D-glucopyranoside and linalyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside were investigated by a chiral GC analysis and compared with those of free citronellol and linalool in the aroma concentrate.

Capsicum↗

PubMed2001

Hepatic phenylalanine metabolism measured by the [13C]phenylalanine breath test.

BACKGROUND: The amino acid clearance test including phenylalanine is known to reflect liver functional reserve, which correlates with surgical outcome; however, the procedure is not clinically useful because of its laborious and time-consuming nature. This study evaluates whether phenylalanine oxidation capacity measured by a breath test could reflect liver functional reserve. DESIGN: We determined phenylalanine oxidation capacity in 42 subjects using the L-[1-13C]phenylalanine breath test (PBT). The 13CO2 breath enrichment was measured at 10-min intervals for 120 min after oral administration of 100 mg of L-[1-13C]phenylalanine. Subjects were divided into the following three groups according to their plasma retention rate of indocyanine green at 15 min (ICG R15): Group I (ICG R15 < 10%), Group II (ICG R15 10--20%), and Group III (ICG R15 > 20%). First, we determined the parameters of the phenylalanine oxidation capacity that differentiated these groups and then, using these parameters, we compared the PBT with the ICG clearance test, Child-Pugh classification score and standard liver blood tests. RESULTS: The %13C dose h(-1) at 30 min and cumulative excretion at 80 min were significantly different among the three groups (P < 0.05). These two parameters significantly correlated with the ICG R15, Child-Pugh classification score (P < 0.0001) and results of standard liver blood tests (P < 0.05). CONCLUSIONS: Phenylalanine oxidation capacity measured by the PBT was reduced according to the severity of liver injury assessed by the ICG clearance test, Child-Pugh classification, and standard liver blood tests. These results indicate that the PBT can be used as a noninvasive method to determine liver functional reserve.

Administration, Oral↗

PubMed2001

Identification of the critical spinal arteries with F wave-polysynaptic response complex monitoring: an experimental study.

PURPOSE: The main cause of paraplegia after surgery for descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms is spinal cord ischemia caused by ligation of the critical spinal arteries that are associated with the great radicular artery (GRA). In this experimental study, we attempted to identify the critical spinal arteries with F wave-polysynaptic response complex (FPC) monitoring. The FPC, which we are using as a monitor of spinal cord ischemia, is myogenic potentials evoked by the tibial nerve stimulation through the anterior horn cells. METHOD: In 18 rabbits, infrarenal lumbar arteries were clamped until there was an FPC amplitude reduction (FPCAR) of at least 60%. The rabbits were classified according to the number of arteries clamped to produce the FPCAR (group A, 1 artery; group B, 2 arteries; group C, 3 arteries). Selective angiography of each lumbar artery was performed in all rabbits. RESULTS: An FPCAR was observed in all 18 rabbits. In all nine rabbits in group A, the FPCAR was caused by the clamping of one particular lumbar artery. The GRA was shown by means of selective angiography to originate directly from this lumbar artery. In the nine rabbits in groups B and C, 11 FPCARs were observed. Of these, nine FPCARs in nine rabbits were caused by the clamping of lumbar arteries that included the vessel from which the GRA originated. CONCLUSION: Temporary clamping of lumbar arteries with FPC monitoring can be used as a means of detecting the critical spinal arteries from which the GRA originates.

Action Potentials↗

PubMed2001

Kinetics of urinary trypsin inhibitor in patients undergoing partial hepatectomy.

BACKGROUND: The kinetics and role of urinary trypsin inhibitor (UTI) in liver surgery are unclear. We investigated the effects of preoperative liver function and the extent of liver resection on postoperative UTI synthesis in the liver after partial hepatectomy. METHODS: Sixty-one consecutive patients who underwent liver resection were the subjects of the study. Plasma and urine UTI, plasma C reactive protein (CRP) and plasma and urine creatinine were measured perioperatively. RESULTS: Although the average plasma UTI level did not change significantly, the average urine UTI level per day showed a change similar to that of the average plasma CRP level, reaching a maximum of approximately eight times the preoperative level on the second postoperative day (86,610 +/- 53,109 U/day). The maximum postoperative increase in urine UTI excretion per day (delta-uUTImax) correlated significantly with the maximum increase in CRP and the increase in creatinine clearance. Multiple regression analysis revealed that delta-uUTImax was significantly and positively correlated with the indocyanine green plasma disappearance rate and operation duration, and negatively correlated with the resection rate. CONCLUSIONS: The postoperative urine UTI level may reflect preoperative liver function and the extent of liver resection after partial hepatectomy.

Adult↗

PubMed2001

Headspace constituents of the tree remain of Cinnamomum camphora.

The volatile ingredients isolated from a fresh tree of Cinnamomum camphora (camphor tree) and from a tree remain of C. camphora were collected by using headspace techniques and analyzed by means of gas chromatography/mass spectrometry (GC/MS). 99.77% of the constituents consisting 23 components from the fresh tree, 98.68% of the constituents consisting 24 components from the tree remain were identified. Of these ingredients, camphor was obtained as the most abundant component.

Gas Chromatography-Mass Spectrometry↗

PubMed2001

First isolation of geranyl disaccharides from ginger and their relations to aroma formation.

Three geraniol glycosides were isolated from immature fresh ginger rhizomes (Zingiber officinale Roscoe). Their structures were identified as geranyl 6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside (1) geranyl 6-O-beta-D-apiofuranosyl-beta-D-glucopyranoside (2) and geranyl 6-O-beta-D-xylopyranosyl-beta-D-glucopyranoside (3) by spectrometric analyses. After incubating each glycoside with a crude enzyme solution prepared from ginger, geraniol was liberated in all of those fractions. This result indicates that the glycosides are related to the formation of geraniol-related compounds in ginger aroma.

Acyclic Monoterpenes↗

PubMed2001

Phase I studies of cisplatin and docetaxel administered by three consecutive weekly infusions for advanced non-small cell lung cancer in elderly and non-elderly patients.

BACKGROUND: To determine the maximum tolerated dose and recommended dose of cisplatin and docetaxel administered by three consecutive weekly infusions in both non-elderly (< or =74 years) and elderly (> or =75 years) patients, we conducted two independent phase I studies for nonelderly and elderly patients with non-small cell lung cancer. METHODS: Between April 1998 and September 1999, 26 non-elderly (median, 54 years; range, 44-73 years) and 12 elderly (median, 76 years; range, 75-80 years) patients with non-small cell lung cancer were entered in these studies. The eligibility criteria of both cohorts were identical except for age. Chemotherapy consisted of cisplatin 25 mg/m2 and an escalated dose of docetaxel on days 1, 8 and 15 every 4 weeks. The initial dose of docetaxel was 20 mg/m2 and it was increased by 5 mg/m2 at each dose level. RESULTS: In the non-elderly and elderly cohorts, up to 45 or 25 mg/m2 of docetaxel, respectively, were administered. Dose-limiting toxicities were neutropenia, liver damage, pneumonia and omission of treatment on day 15 by leukopenia and refusal in the non-elderly cohort; pneumonia and omission of treatment on day 15 by refusal due to fatigue/asthenia or fever in the elderly cohort. We considered the recommended doses for phase II studies were cisplatin 25 mg/m2 and docetaxel 35 mg/m2 on days 1, 8 and 15 for non-elderly patients and cisplatin 25 mg/m2 and docetaxel 20 mg/m2 on days 1, 8 and 15 for elderly patients. Seven of 26 (27%) and seven of 12 (58%) patients achieved a partial response, median survival times were 8.7 and 7.2 months and 1 year survival rates were 27 and 27% in the non-elderly and elderly cohorts, respectively. CONCLUSIONS: Further evaluation of this combination chemotherapy is warranted for both nonelderly and elderly patients with non-small cell lung cancer but the dose of docetaxel should be lower for elderly than non-elderly patients.

Adult↗

PubMed2001

Phase I and pharmacological study of paclitaxel given over 3 h with cisplatin for advanced non-small cell lung cancer.

BACKGROUND: To establish the toxicities and maximum tolerated dose of paclitaxel given over 3 h in combination with cisplatin, to determine the pharmacokinetic profiles of these two drugs and to observe their antitumor activity, we conducted a combination phase I study in non-small cell lung cancer. METHODS: Patients received paclitaxel doses of 150-210 mg/m2 given over 3 h and cisplatin doses of 60-80 mg/m2 as a 1 h infusion 2 h after the end of the paclitaxel infusion. RESULTS: A total of 25 patients with previously untreated non-small cell lung cancer were enrolled. Granulocytopenia was the most frequent hematological toxicity and the most prominent non-hematological toxicity was sensory dominant neuropathy. Two of six patients experienced dose limiting toxicities (leukopenia, infection and neuropathy) at a dose of paclitaxel 210 mg/m2 and cisplatin 60 mg/m2, which was considered the maximum tolerated dose. There were seven partial responses among 24 evaluable patients, for an overall response rate of 29%. The median survival time was 341 days and the 1 year survival rate was 45.8%. As the paclitaxel pharmacokinetic parameters in this study were consistent with those of our previous single agent study, we found no significant drug-drug interaction between the 3 h infusion paclitaxel and cisplatin. CONCLUSION: The recommended doses for further study are determined to be paclitaxel 180 mg/m2 and cisplatin 80 mg/m2. This is a well-tolerated and active regimen for non-small cell lung cancer. In view of the promising survival outcome, further evaluation in prospective randomized trials versus other regimens is warranted.

Adult↗

PubMed2001

Liver resection without total vascular exclusion: hazardous or beneficial? An analysis of our experience.

OBJECTIVE: To evaluate retrospectively the safety and radicality of liver resection performed without total vascular exclusion (TVE). SUMMARY BACKGROUND DATA: TVE is recommended for safe liver surgery, at least in the case of resection of the paracaval portion of the liver. However, it has some drawbacks because of its invasiveness. METHODS: The authors retrospectively evaluated 329 of 471 consecutive patients who underwent liver resection from October 1994 to October 1999. All of these patients had tumors involving segments 1, 7, or 8 or the cranial portion of segment 4, or underwent major hepatectomies that required exposure of the inferior vena cava (IVC), the main trunks of the hepatic veins, or both. Sixty-four patients underwent resection that included segment 1, with or without the reconstruction of the IVC, the hepatic vein, or both. RESULTS: Three hundred twenty-four of 329 procedures were done under intermittent warm ischemia; no clamping methods were used in 6. TVE was never needed. There were no postoperative 30-day deaths. The complication rate was 25.5%, and only 2.1% had major complications. Only 13 (3.9%) patients required whole blood transfusion. Part of the wall of the IVC was resected in six patients, and the hepatic veins were reconstructed in four. Surgical clearance was achieved in all patients undergoing surgery for a tumor. CONCLUSIONS: These results show that liver surgery performed without TVE is safe and effective even in aggressive procedures for liver tumors involving the cavohepatic junction. Therefore, TVE should be further restricted to exceptional patients.

Adolescent↗