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Biomedical subjects

S Kurokawa

Publications and source records attributed to S Kurokawa.

At least 19 recordsLinked to original sources
PubMed2007

Correlation between heart rate variability and haemodynamic fluctuation during induction of general anaesthesia: comparison between linear and non-linear analysis.

The objective of this study was to compare linear and non-linear analysis of heart rate variability (HRV) in terms of correlation with haemodynamic fluctuation during induction of general anaesthesia. Pre-operatively, HRV was estimated by the MemCalc method in 114 patients scheduled for general anaesthesia. After anaesthesia was induced with propofol, fentanyl and vecuronium bromide, tracheal intubation was performed. Haemodynamic fluctuations during induction of anaesthesia were recorded and the correlation between pre-operative HRV and haemodynamic fluctuation was examined using logistic regression analysis. As an index of non-linear analysis of HRV, ultra short-term entropy (UsEn) correlated better with blood pressure fluctuation than did the ratio of the power of low frequency component of HRV to that of high frequency component (LF/HF). In contrast, although LF/HF significantly correlated with heart rate increase caused by tracheal intubation, the correlation between UsEn and heart rate fluctuation was not significant.

Adult↗
PubMed2005

Tumour matrilysin expression predicts metastatic potential of stage I (pT1) colon and rectal cancers.

BACKGROUND AND AIMS: Nodal metastases are indisputable determinants of prognosis for colon and rectal cancer. Using classical histological criteria, many attempts to predict nodal metastasis have failed, preventing the adequate management of stage I (pT1) cancer. We investigated the role of tumour matrilysin in predicting metastatic potential, and discuss its potential use in individualising treatment of pT1 colon and rectal cancer. METHODS: The gene signature associated with nodal metastasis was investigated by cDNA array in 24 colon and rectal cancers. We studied 494 colon and rectal cancer patients to identify risk factors for nodal metastasis and evaluated the potential to predict nodal metastasis by either the logistic regression model or the Bayesian neural network model with built-in matrilysin. We then inferred possible causality of nodal metastasis from structural equation modelling. RESULTS: cDNA array revealed that matrilysin was maximally upregulated in the metastasis signature identified. Tumour matrilysin expression emerged as a stage independent risk factor for nodal metastasis, resulting in a similar predictive performance in receiver operating characteristic curve analysis in the two models. A Bayesian approach called automatic relevance determination identified matrilysin as one of the most relevant predictors examined. Structural equation modelling suggested possible direct causality between matrilysin and nodal metastasis. CONCLUSIONS: We have provided evidence that tumour matrilysin expression is a promising biomarker predicting nodal metastasis of colon and rectal cancer. Analysis of tumour matrilysin expression would help clinicians achieve the goal of individualised cancer treatment based on the metastatic potential of pT1 colon and rectal cancer.

Adenocarcinoma↗
PubMed2004

Molecular and morphological differentiation between the crop and weedy types in velvetleaf (Abutilon theophrasti Medik.) using a chloroplast DNA marker: seed source of the present invasive velvetleaf in Japan.

A comparison of chloroplast DNA (cpDNA) sequences was carried out between the crop and weed types of Abutilon theophrasti to clarify the seed source of the present weedy velvetleaf in Japan. A sequencing analysis of approx. 6% of the chloroplast genome (ca 10 kbp) detected three nucleotide substitutions, one six-base-pair insertion/deletion (indel) and one 30-base pair inversion, which distinguish two haplotypes of cpDNA. A PCR-based survey of the indel and the inversion revealed that the 93 accessions of velvetleaf collected from the world could be divided into two groups. A morphological marker (capsule color) could be used to discriminate the crop type and the weed type, and hence, along with cpDNA haplotype, to distinguish three genotypes (Type I, II, and III). All Japanese cultivars and crop accessions from other countries were Type I. Weed types were divided into Type II and III. All of the samples from the USA, and the samples taken from grain imports to Japan were Type III. Since most of the weedy types distributed in Japan were of Type III, it is argued that they were introduced as seeds in the imported grain. We also found that the Type II plants sporadically occurred in Japan. It is suggested that they originated as hybrids, with indigenous cultivars as the maternal ancestor. Such hybrids must have survived since the cessation of velvetleaf cultivation about a century ago.

Chloroplasts↗
PubMed2002

Photoelectron trapping in quadrupole and sextupole magnetic fields.

A photoelectron-trapping phenomenon has been found in the simulation of the photoelectron cloud. It is found that the photoelectrons can be trapped in the quadrupole and sextupole magnetic fields for very long time until it longitudinally drifts out of the magnets, even a long bunch train separation is not sufficient to clear up the photoelectrons. Therefore, such a kind of long time trapped photoelectron cloud can cause coupled bunch instability. The trapping phenomenon is strongly beam dependent, especially on the bunch length. There is no such kind of trapping if the positron beam does not disturb the photoelectrons during the whole process. There is also no trapping for positron bunch with bunch length longer than the period of the photoelectron's gyration motion at the mirror points. The trapping is a mirror field trap which is caused by beam disturbance. The trapping phenomenon and mechanism will be presented in detail.

Journal Article↗
PubMed2001

Behavior of fascicles and tendinous structures of human gastrocnemius during vertical jumping.

Behavior of fascicles and tendinous structures of human gastrocnemius medialis (MG) was determined by use of ultrasonography in vivo during jumping. Eight male subjects jumped vertically without countermovement (squat jump, SQJ). Simultaneously, kinematics, kinetics, and electromyography from lower leg muscles were recorded during SQJ. During phase I (-350 to -100 ms before toe-off), muscle-tendon complex (MTC) length was almost constant. Fascicles, however, shortened by 26%, and tendinous structures were stretched by 6%, storing elastic energy of 4.9 J during phase I. During phase II (-100 ms to toe-off), although fascicles generated force quasi-isometrically, MTC shortened rapidly by 5.3%, releasing prestored elastic energy with a higher peak positive power than that of fascicles. Also, the compliance of tendinous structures in vivo was somewhat higher than that of external tendon used in the simulation studies. The results demonstrate that the compliance of tendinous structures, together with no yielding of muscle fibers, allows MTC to effectively generate relatively large power at a high joint angular velocity region during the last part of push-off.

Adult↗
PubMed2001

Segmental multicystic dysplastic kidney in an adult woman.

We report a case of unilateral segmental multicystic dysplastic kidney (SMCDK) in an adult woman. A 42-year-old woman presented with abdominal distension and gross hematuria. The preoperative diagnosis was cystic renal cell carcinoma, and a radical nephrectomy was performed. Histopathologically, the resected kidney was SMCDK with severe hydronephrosis.

Adult↗
PubMed2001

Usefulness of BMIPP SPECT to evaluate myocardial viability, contractile reserve and coronary stenotic progression after reperfusion in acute myocardial infarction.

Using combined 123I-BMIPP (BMIPP), 201Tl (Tl) and 99mTc-PYP (PYP) myocardial SPECT imaging, risk areas of acute myocardial infarction were documented in the acute stage, and then these images were evaluated for how well they reflected muscle viability, contractile reserve and coronary stenotic progression subsequent to reperfusion therapy. Patients who only experienced a first attack of myocardial infarction were enrolled. In total, 36 cases who had had the occluded artery successfully reperfused were examined during the past year. They had no significant vessel disease except for the culprit single artery. The patients were comprised of 32 men and 4 women. The mean age was 59.5 years. All patients underwent coronary angiography and left ventricular (LV) angiography in the emergency room. BMIPP/Tl and PYP myocardial SPECT were conducted in the acute stage and chronic stage. In the chronic stage LV angiography was repeated to assess the improvement of LV wall motion. The response to postextrasystolic potentiation (PESP) testing was performed to estimate myocardial contractile reserve. The risk area of acute myocardial infarction (AMI) was documented by reduced BMIPP accumulation. The size of reduced BMIPP accumulation was larger than that of PYP accumulation. A BMIPP/Tl discrepancy and PYP accumulation were documented to assess myocardial viability. Both improvement in LV wall motion and augmentation of PESP response were more closely related to a BMIPP/Tl discrepancy in the presence or absence of PYP accumulation. Therefore, it would be possible to evaluate myocardial viability and contractile reserve by the BMIPP/Tl discrepancy. In patients with good viability, it is important to predict whether there is coronary stenotic progression or not. In this study, we demonstrated that most patients with improved BMIPP images had no significant progression at the site of intervention. Serial observation of BMIPP images from the acute stage to the chronic stage might enable us to predict the progression of coronary stenosis.

Adult↗
PubMed2001

[Clinical evaluation of urinary nuclear matrix protein 22 as a marker for bladder cancer].

The purpose of this study is to evaluate the clinical usefulness of urinary nuclear matrix protein 22 (NMP22) as a marker for bladder cancer. We examined the positive rates of NMP22 test, urinary cytology and bladder tumor antigen (BTA) test, and compared the positive rate of NMP22 test with that in urinary cytology and BTA test. Urine samples were obtained from 50 patients with histologically confirmed bladder cancer before the treatment. The samples were examined by NMP22 test, urinary cytology and BTA test. In 50 patients with bladder cancer, the overall positive rate was 40% for NMP22 test, 40% for urinary cytology, and 16% for BTA test. A combination of NMP22 test and urinary cytology showed a significantly higher positive rate (54%) as compared to NMP22 test or urinary cytology alone. When NMP22 test and urinary cytology were compared for tumor size, number, shape, stage and grade, NMP22 test showed a significant higher positive rate than urinary cytology in grade 1 bladder cancer. In conclusion, although NMP22 test and urinary cytology gave a similar positive rate, a combination of NMP22 test and urinary cytology is more useful than the NMP22 test or urinary cytology alone for monitoring of bladder cancer.

Adult↗
PubMed2000

Randomized controlled trial of twice-a-day administration of natural interferon beta for chronic hepatitis C.

We conducted a randomized controlled trial to assess the efficacy of twice-a-day administration of natural interferon beta (IFNbeta) as an induction of IFN therapy for chronic hepatitis C. Seventy-one patients with chronic hepatitis C were enrolled into the trial and randomly assigned into three treatment groups. Six million units (MU) of IFNbeta were administered once-a-day for the first 4 weeks, and then thrice weekly for 12 weeks in 20 patients (once-a-day group). Three milion units of IFNbeta were administered twice-a-day for the first 2 weeks, 6 MU once-a-day for the next 2 weeks, and then thrice weekly for 12 weeks in 23 patients (twice-a-day+beta group), or 6 MU of lymphoblastoid IFNalpha were administered thrice weekly for the last 12 weeks instead of IFNbeta in 28 patients (twice-a-day+alpha group). Four patients in once-a-day group (20%), 9 in twice-a-day+beta group (39%), and 12 in twice-a-day+alpha group (43%) obtained sustained response. Sustained response rate in twice-a-day groups was higher than in once-a-day group, although there was no statistical significance. The present study suggested the possible superiority of twice-a-day administration of IFNbeta as an induction therapy to once-a-day administration, but further studies are needed to confirm this regimen.

Journal Article↗
PubMed2000

Microsatellite instability in patients with multiple primary cancers of the gastrointestinal tract.

BACKGROUND: Little is known about the genetic alterations in multiple primary cancers of the gastrointestinal tract. Microsatellite instability (MSI) is frequently observed in hereditary non-polyposis colorectal cancer (HNPCC), and multiple primary cancers is a feature of this syndrome. AIMS: To identify MSI incidence, target gene mutation, and mismatch repair (MMR) protein status in patients with multiple primary cancers of the gastrointestinal tract. SUBJECTS: Fifty seven cancers from 22 Japanese patients with multiple primary cancers of the stomach, duodenum, colon, and rectum. METHODS: MSI was examined at 5-7 microsatellite loci. Mutation analysis for TGFbetaRII, IGFIIR, and BAX was performed in cancers with MSI. MMR protein status was examined by immunohistochemical analysis using a monoclonal antibody against hMSH2 and hMLH1. RESULTS: MSI was observed in 16 of 22 patients (73%) and in 29 of 57 lesions (51%). High frequency MSI (MSI-H) was found often in patients with multiple cancers in the same organ (p = 0.042), especially in multiple gastric cancer patients (p = 0.038). In contrast, patients with multiple cancers in different organs had a tendency to show low frequency MSI (MSI-L) or microsatellite stable (MSS) phenotype. Both target gene mutation and decreased expression of MMR protein were found only in seven lesions of three patients with MSI at more than four microsatellite loci. CONCLUSIONS: These results suggest that genetic instability may play an important role in the development of multiple gastrointestinal cancers but there may be different genetic alterations between multiple gastrointestinal cancers of the same and different organs.

Aged↗
PubMed2000

[Spontaneous occlusion of a dissecting aneurysm in the shape of "two dumplings on a skewer" at righ posterior inferior cerebellar artery (PICA): report of a case and neuroradiological findings].

We present a case of a spontaneous dissecting aneurysm at the vertebrobasilar artery including the right PICA in a 44-year-old man, who suffered from headache, hiccup and ataxic gait. The arteriograms showed an irregular narrowing and dilatation in the right PICA and in the vertebrobasilar artery, and showed fusiform dilatations in the bilateral middle cerebral arteries. We observed intramural hematoma and true lumen at the right PICA dissecting aneurysm on T1-weighted images on magnetic resonance imaging (1.5T, MRI), and the intimal flap was enhanced on T1-weighted image after intravenous injection of Gd-DTPA. The shape of the intramural hematoma showed a unique "two dumplings on a skewer" appearance, and the intensity of its hematoma in the false lumen decreased in gradient from adventitia to intimal flap on T1-weighted image on MRI. The dissecting aneurysm of the PICA was occluded spontaneously 1 month later, and it caused cerebellar infarction. However, the patient has been left only with the symptom of slight trunkal ataxia. Various shapes of intramural hematomas on MRI have been reported by Kitanaka in association with intracranial vertebrobasilar dissections. We suggest that "two dumplings on a skewer" shape which corresponds to the flow void of the true lumen, accompanied by intramural hematoma and enhanced intimal flap, on contrast-enhanced T1-weighted image, should be regarded as a true "diagnostic sign" of a dissecting aneurysm.

Adult↗
PubMed2000

[Anesthetic management of thrombectomy for left ventricular huge mobile thrombus].

A 45 year-old male underwent thrombectomy for huge mobile thrombus and aneurysmectomy in the left ventricle. Despite of the patient's preoperative poor cardiac function and difficulties in weaning from cardiopulmonary bypass, he could recover with the aid of left ventricular bypass for 6 days without complications such as thromboembolism. Intraoperative transesophageal echocardiography was useful in observation of thrombus, decision making in the adaptation and type-selection of mechanical ventricular support, and evaluation of its efficacy.

Anesthesia, Intravenous↗
PubMed2000

[Anesthetic management with veno-venous extracorporeal membrane oxygenator (VV-ECMO) in a patient with severe tracheobronchial stenosis].

We conducted an anesthetic management to perform tracheostomy and tracheolysis in a 33 year-old female with severe stenosis extending to the lower trachea and right main bronchus. The minimal diameter of the stenotic lesion of the trachea was 3 mm according to the preoperative examinations including tomography, CT scan and magnetic resonance imaging. Since there was a high risk of airway collapse during anesthetic induction that could have made ventilation impossible, we decided to apply VV-ECMO to support gas-exchange prior to anesthetic induction. Blood gas analysis showed good results, and sufficient oxygenation and stable circulation were achieved during surgical procedures. Total intravenous anesthesia with propofol and fentanyl could provide adequate depth of anesthesia during surgery and rapid recovery with good spontaneous respiration after the termination of the infusion. VV-ECMO was a useful method to support gas-exchange in a case not requiring circulatory assistance without uneven oxygenation sometimes observed in VA-ECMO.

Adult↗
PubMed1999

Hypokalemia with syncope caused by habitual drinking of oolong tea.

A 61-year-old woman developed hypokalemia, atrioventricular block and ventricular tachycardia with syncope after habitual drinking 2 to 3 liters of oolong tea per day. She had been suffering from rheumatoid arthritis and Sjögren's syndrome and her serum albumin was decreased (2.9 g/dl). Oolong tea contains caffeine at approximately 20 mg/dl. Great quantities of caffeine can induce hypokalemia. The serum protein binding caffeine is albumin. Accordingly, in patients with hypoalbuminemia, caffeine is apt to induce hypokalemia. This case suggested that great quantities of oolong tea, one of the so-called "healthy" drinks, result in serious symptoms for patients with hypoalbuminemia.

Binding Sites↗
PubMed1999

[Anesthetic management for pericardial fenestration in a hypertrophic cardiomyopathy (HCM) patient with massive pericardial effusion].

A 65 year-old male with HCM had progressively increased pericardial effusion. He also had atrial fibrillation (af), cardiac systolic dysfunction and chronic renal failure needing hemofiltration. Pericardial fenestration was carried out to improve diastolic function. Anesthetic management with fentanyl plus low-dose propofol infusion and postoperative analgesia with epidural morphine were effective for hemodynamic stability to prevent myocardial depression and to control ventricular response to atrial fibrillation. Intraoperative trans-esophageal echocardiography (TEE) monitoring was very useful for fluid therapy, inotropic support and estimation of systolic and diastolic function.

Aged↗