Biomedical subjects

Y Yamazaki

Publications and source records attributed to Y Yamazaki.

At least 91 records · Page 5Linked to original sources

PubMed2001

Pancreatic granular cell tumor combined with carcinoma in situ.

A 58-year-old man was treated for a granular cell tumor (GCT) of the pancreas; a very rarely occurring tumor. The patient, who had been followed for 6 years due to alcoholic hepatitis, chronic pancreatitis and elevated carcinoembryonic antigen (CEA) levels from smoking, was admitted to our hospital for evaluation of back pain, diarrhea and constipation. The patient was diagnosed as having pancreatic head cancer using clinical imaging studies, and a pylorus-preserving pancreatico-duodenectomy was done. In the resected specimen, a white tumor measuring 13 mm in diameter was observed at the pancreatic head, and there was marked fibrous change surrounding the tumor. The microscopic appearance of the pancreas showed atrophy of acinar cells, fibrosis, and dilatation of the main pancreatic duct (MPD). Within the tumor were oval cells with low-grade atypia and an increased number of diffuse eosinophilic granules. Neither mitosis nor invasive findings were observed. Periodic acid-Schiff staining and immunohistochemical staining for the S-100 protein were positive, thus the tumor was diagnosed as a benign GCT. In addition, carcinoma in situ was found at the dilated MPD. Therefore, this patient was diagnosed as having GCT with carcinoma in situ of the pancreas. To the best of our knowledge, this is only the fourth case of GCT of the pancreas to be reported.

Biomarkers, Tumor↗

PubMed2001

Dartos flap interposition in the surgical repair of rectourethral fistulas.

BACKGROUND: Multilayer closures are important techniques in urethral fistula repair. We report our experience with dartos flap interposition in the repair of rectourethral fistula. METHODS/RESULTS: A tip of a V-shaped scrotal skin flap is mobilized and de-epithelialized to develop a dartos flap. Two patients with a rectourethral fistula underwent fistula closure covered with this dartos flap. The surgical repair was successful in both cases and neither patient showed any late complication. CONCLUSIONS: A scrotal dartos flap is well vascularized and easy to mobilize. We believe this technique is helpful in preventing postoperative complications following complex posterior urethral surgery.

Adult↗

PubMed2001

Development and characterization of a monoclonal antibody specific for fucosyltransferase VII (Fuc-TVII): discordant expression of CLA and Fuc-TVII in peripheral CD4+ and CD8+ T cells.

Although cutaneous lymphocyte-associated antigen (CLA) is thought to be specifically expressed on skin "homing" T cells, it has become clear that CLA is not directly involved in binding to E-selectin but represents an excellent marker for high levels of fucosyltransferase VII (Fuc-TVII): Fuc-TVII can regulate the ability of T cells to migrate into the skin by generating a binding site for E-selectin. In this study, by using a novel monoclonal antibody for Fuc-TVII, we investigated whether expression of Fuc-TVII could be selectively detected in various CLA+ cell lines and peripheral blood T cells. Fuc-TVII was readily detected in the cytoplasm, but not in the membrane, of CLA+ cell lines. Cytoplasmic Fuc-TVII expression was also detectable in both CD4+ and CD8+ T cells purified from peripheral blood mononuclear cells. Nevertheless, there were significant numbers of CLA-expressing CD4+ or CD8+ T cells that did not coexpress Fuc-TVII, and vice versa: either the CD4+ or the CD8+ T cell population consisted of a variable ratio of CLA+ Fuc-TVII+, CLA+ Fuc-TVII-, and CLA- Fuc-TVII+ cells; and CLA+ Fuc-TVII- cells were the most abundantly identifiable phenotype in peripheral blood CD4+ and CD8+ T cells. Thus, according to their expression pattern, skin "homing" T cells can be subdivided into at least three populations, CLA+ Fuc-TVII+, CLA+ Fuc-TVII-, and CLA- Fuc-TVII+ cells. Our study provides convincing evidence that skin "homing" T cells are phenotypically heterogenous and that Fuc-TVII expression, in combination with CLA expression, is a useful phenotypic marker for identifying skin "homing" T cells in mixed cell populations.

Antibodies, Monoclonal↗

PubMed2001

Alkaloids and flavonoids from peanut skins.

Separation of the water-soluble fraction of peanut skins led to the isolation of 8 flavonoids and two novel indole alkaloids. Two new flavonoid glycosides have been identified as isorhamnetin 3-O-[2-O-beta-glucopyranosyl-6-O-alpha-rhamnopyranosyl]- beta-glucopyranoside and 3',5,7-trihydroxyisoflavone-4'-methoxy-3'-O-beta-glucopyranoside. Two alkaloids are 2-methoxyl-3-(3-indolyl)-propionic acid and 2-hydroxyl-3-[3-(1-N-methyl)-indolyl]-propionic acid. These isolated flavonoids were evaluated for their free radical scavenging activity and protein glycation inhibitory effects.

Alkaloids↗

PubMed2001

Effect of varying light intensity on maximal power production and selected metabolic variables.

This study was designed to examine the effect of exposure to two levels of light intensity (bright; 5000 lux, dim; 50 lux) prior to supramaximal cycle exercise on performance and metabolic alterations. The exercise was performed after bright and dim light exposure for 90 minutes. Ten male long-distance runners volunteered to take part in the study. They performed 45-sec supramaximal exercise using a cycle ergometer in a 500-lux. Mean power output was measured during the exercise. Lactate and ammonia in the blood and epinephrine and norepinephrine concentrations in plasma were measured at rest immediately after bright and dim light exposures and after the exercise. Bright and dim light exposure prior to exercise did not significantly affect the power output during the exercise. Blood glucose concentration immediately after exercise and plasma epinephrine during the resting period were significantly lower after bright light exposure compared with dim light exposure (p < 0.05). No significant difference was found in blood lactate, ammonia, or plasma norepinephrine levels after exercise following bright and dim light exposures. This study demonstrated that bright light stimulation prior to supramaximal exercise decreases glucose and epinephrine levels, but is not related to physical performance.

Ammonia↗

PubMed2001

Relationship between circulating high density lipoprotein concentrations and interleukin-6 release during abdominal operations.

OBJECTIVE: To investigate whether circulating high density lipoprotein (HDL) concentrations influence inflammatory cytokine release during abdominal operations. SETTING: University Hospital, Japan. PATIENTS: 30 patients who underwent curative operations for gastric cancer. MAIN OUTCOME MEASURES: Serum HDL and cytokine concentrations were measured preoperatively, and portal and systemic blood samples were taken for the analysis of cytokine and endotoxin concentrations during operations. RESULTS: Portal blood interleukin-6 (IL-6) values of patients with low serum HDL concentrations (n = 6) (< 0.9 mmol/L) were significantly (p < 0.01) higher than those in patients with normal or high HDL concentrations (n = 24) (> or = 0.9 mmol/L) (80.63 (74.62) pg/ml (mean (SD)) compared with 10.25 (9.61) pg/ml.). Moreover, an inverse correlation (r = -0.43, p < 0.05) was found between portal blood IL-6 concentrations and circulating HDL concentrations. CONCLUSIONS: We suggest that serum HDL concentrations influence IL-6 release in response to abdominal operations. Circulating HDL particles may reduce endotoxin-induced IL-6 release in humans.

Aged↗

PubMed2001

An anisotropic diffusion method for denoising dynamic susceptibility contrast-enhanced magnetic resonance images.

The purpose of this study was to present an application of a novel denoising technique for improving the accuracy of cerebral blood flow (CBF) images generated from dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI). The method presented in this study was based on anisotropic diffusion (AD). The usefulness of this method was firstly investigated using computer simulations. We applied this method to patient data acquired using a 1.5 T MR system. After a bolus injection of Gd-DTPA, we obtained 40-50 dynamic images with a 1.32-2.08 s time resolution in 4-6 slices. The dynamic images were processed using the AD method, and then the CBF images were generated using pixel-by-pixel deconvolution analysis. For comparison, the CBF images were also generated with or without processing the dynamic images using a median or Gaussian filter. In simulation studies, the standard deviation of the CBF values obtained after processing by the AD method was smaller than that of the CBF values obtained without any processing, while the mean value agreed well with the true CBF value. Although the median and Gaussian filters also reduced image noise, the mean CBF values were considerably underestimated compared with the true values. Clinical studies also suggested that the AD method was capable of reducing the image noise while preserving the quantitative accuracy of CBF images. In conclusion, the AD method appears useful for denoising DSC-MRI, which will make the CBF images generated from DSC-MRI more reliable.

Aged↗

PubMed2001

Accuracy of deconvolution analysis based on singular value decomposition for quantification of cerebral blood flow using dynamic susceptibility contrast-enhanced magnetic resonance imaging.

Deconvolution analysis (DA) based on singular value decomposition (SVD) has been widely accepted for quantification of cerebral blood flow (CBF) using dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI). When using this method, the elements in the diagonal matrix obtained by SVD are set to zero when they are smaller than the threshold value given beforehand. In the present study, we investigated the effect of the threshold value on the accuracy of the CBF values obtained by this method using computer simulations. We also investigated the threshold value giving the CBF closest to the assumed value (optimal threshold value) under various conditions. The CBF values obtained by this method largely depended on the threshold value. Both the mean and the standard deviation of the estimated CBF values decreased with increasing threshold value. The optimal threshold value decreased with increasing signal-to-noise ratio and CBF, and increased with increasing cerebral blood volume. Although delay and dispersion in the arterial input function also affected the relationship between the estimated CBF and threshold values, the optimal threshold value tended to be nearly constant. In conclusion, our results suggest that the threshold value should be carefully considered when quantifying CBF in terms of absolute values using DSC-MRI for DA based on SVD. We believe that this study will be helpful in selecting the threshold value in SVD.

Algorithms↗

PubMed2001

Sequence analysis of fibroblast growth factor receptor 2 ( FGFR2 ) in Japanese patients with craniosynostosis.

Recently, mutations of the fibroblast growth factor receptor ( FGFR ) genes have been detected in syndromic craniosynostosis. We examined nucleotide sequences of FGFR2 in Japanese craniosynostosis patients (Crouzon syndrome: 9 cases; Apert syndrome: 6 cases; scaphocephaly: 3 cases as non-syndromic patients) by polymerase chain reaction (PCR) followed by direct sequencing methods. The results demonstrated FGFR2 heterozygous mutations at codons 252, 290 of exon 7, and at codon 342, 354 of exon 9 in Crouzon syndromes. In Apert syndrome patients, Ser252Trp and Pro253Arg were detected in five and one patients, respectively. No mutation was detected in one case of Crouzon, all cases of scaphocephaly and healthy individuals. Thus far sequence analysis of FGFR2 in syndromic craniosynostosis has been reported in many white patients, whereas in Japanese only several cases have been studied. The current study with 18 patients confirmed that a similar series of mutations occur in Japanese patients as in white patients regardless of ethnicity and environment. The frequency of the mutation was 82% (9/11 cases) in Japanese Crouzon patients. The ratio of S252W:P253R was 5 : 1 in Japanese Apert patients. Moreover, in Japanese Apert patients, complication rate of cleft palate was 60% for mutation of Ser252Trp and 0 of 2 patients for Pro253Arg, with their syndactyly score being 4.90 and 5.50, respectively.

Acrocephalosyndactylia↗

PubMed2001

Relaxant effects of isoproterenol and selective beta3-adrenoceptor agonists on normal, low compliant and hyperreflexic human bladders.

PURPOSE: We compared the relaxant effects of the stimulation of beta-adrenoceptors with isoproterenol and of drugs selective for beta-adrenoceptor subtypes in detrusor preparations from patients with normal and neurogenic bladder, respectively. MATERIALS AND METHODS: We studied in vitro preparations of a cystometrically normal, low compliant and hyperreflexic bladder from 45, 26 and 7 patients, respectively. RESULTS: Isoproterenol relaxed concentration dependently and with the same potency as detrusor preparations obtained from normal and neurogenic bladders. In 37 normal detrusor, 25 low compliant and 7 hyperreflexic cases pD2 values were 6.36, 6. 25 and 6.38, respectively. Maximal relaxation did not differ significantly among the 3 groups (about 80% of 10-5 M. forskolin induced relaxation). Neither the beta1-/beta2-adrenoceptor agonist dobutamine nor the beta2-adrenoceptor agonist procaterol produced any significant relaxation of preparations from the 3 groups at a concentration of up to 10-5 M. At a concentration of 10-4 M. the preparations were relaxed but neither of these effects reached a maximum. BRL37344A and CL316243, selective beta3-adrenoceptor agonists and CGP-12177A (a selective beta3-adrenoceptor partial agonist and beta1-/beta2-adrenoceptor antagonist) relaxed detrusor preparations from the normal, low compliant and hyperreflexic groups when applied at concentrations greater than 10-6 M. For each agonist the pD2 value did not differ significantly among the 3 groups. CONCLUSIONS: beta-adrenoceptor stimulation is an effective way of relaxing the human detrusor and the effect is similar in normal and neurogenic bladders. A major portion of the relaxant effect of isoproterenol is mediated via beta3-adrenoceptor stimulation. Clinical trials may reveal whether this method is useful for treating bladder overactivity.

Adrenergic beta-Agonists↗

PubMed2001

Doctors' and nurses' attitudes towards and experiences of voluntary euthanasia: survey of members of the Japanese Association of Palliative Medicine.

OBJECTIVE: To demonstrate Japanese doctors' and nurses' attitudes towards and practices of voluntary euthanasia (VE) and to compare their attitudes and practices in this regard. DESIGN: Postal survey, conducted between October and December 1999, using a self-administered questionnaire. PARTCIPANTS: All doctor members and nurse members of the Japanese Association of Palliative Medicine. MAIN OUTCOME MEASURE: Doctors' and nurses' attitude towards and practices of VE. RESULTS: We received 366 completed questionnaires from 642 doctors surveyed (response rate, 58%) and 145 from 217 nurses surveyed (68%). A total of 54% (95% confidence interval (CI): 49-59) of the responding doctors and 53% (CI: 45-61) of the responding nurses had been asked by patients to hasten death, of whom 5% (CI: 2-8) of the former and none of the latter had taken active steps to bring about death. Although 88% (CI: 83-92) of the doctors and 85% (CI: 77-93) of the nurses answered that a patient's request to hasten death can sometimes be rational, only 33% (CI: 28-38) and 23% (CI: 16-30) respectively regarded VE as ethically right and 22% (CI: 18-36) and 15% (CI: 8-20) respectively would practise VE if it were legal. Logistic regression model analysis showed that the respondents' profession was not a statistically independent factor predicting his or her response to any question regarding attitudes towards VE. CONCLUSIONS: A minority of responding doctors and nurses thought VE was ethically or legally acceptable. There seems no significant difference in attitudes towards VE between the doctors and nurses. However, only doctors had practised VE.

Attitude of Health Personnel↗

PubMed2001

Hepatectomy using the coagulating shears type of ultrasonically activated scalpel.

Since the ultrasonically activated scalpel (UAS) incorporates multiple functions, we have used it for hepatectomies. The present study discusses the noteworthy points and problems of use, and shows initial results. Intraoperative ultrasonography is an important tool for comprehending the positional relationship between the plane of division and the main blood vessels. It allows initial adjustment of coagulation and cutting effects according to the rigidity of the liver parenchyma by means of variable ultrasound levels and exchangeable blade tips, and offers good visibility of the cut surface in deep sites as long as adequate tension on the tissue and an upper position for the blade are maintained. 30 patients underwent hepatectomies using the UAS. The amount of blood loss for lobectomy was significantly less than that for partial lobectomy in normal livers in addition to a significant difference between normal and damaged livers in each group according to the extent of resection. There were no serious complications seen in all cases during the operation. The incidence of positive bile leakage was high. It is recommended that bile leakage testing be carried out as thoroughly as possible. There were 3 postoperative bile fistulas and 1 postoperative hemorrhage. In conclusion, although a dramatic improvement in blood loss and shortened operating time could not be obtained in all procedures, the safety and usefulness were demonstrated in lobectomy. The UAS can be considered as a surgical device that can contribute to the efficiency of hepatectomy, depending on the indications selected.

Blood Loss, Surgical↗

PubMed2001

Hypersensitivity pneumonitis induced by spores of Lyophyllum aggregatum.

OBJECTIVES: Lyophyllum aggregatum (LA) is called Shimeji in Japanese and is eaten commonly as a mushroom. Shimeji mushrooms are cultivated in an indoor environment all year round. This study aimed to clarify the clinical features of hypersensitivity pneumonitis (HP) induced by LA. PATIENTS AND SETTING: Ten patients showed mild respiratory symptoms including dry cough, sputum, and low-grade fever. We tried to characterize the clinical features and the findings using chest high-resolution CT (HRCT), pulmonary function tests (PFTs), and BAL fluid (BALF) tests in patients with HP induced by LA. HP was diagnosed from clinical features, HRCT findings, BALF findings, lung histology, and lymphocyte stimulation tests (LSTs) for LA. RESULTS: Laboratory findings showed mean (+/- SD) elevated levels of C-reactive protein (0.78 +/- 1.3 mg/dL), erythrocyte sedimentation rate (48 +/- 23 mm/h), and gamma-globulin (26.9 +/- 7.6%). PFTs revealed a slight decrease in the percentage diffusing capacity of the lung for carbon monoxide, possibly due to the presence of epithelial granulomas in the alveoli. Although 4 of 10 patients showed normal findings on the chest radiograph (CXR), chest HRCT findings of all patients showed centrilobular small nodules and diffuse ground-glass opacities. The BALF testing revealed an increase in total cell counts, showing predominantly activated T lymphocytes. The CD4/CD8 cell ratio was significantly decreased (0.5 +/- 0.3). The results of the LSTs were positive in seven of seven cases. CONCLUSIONS: Since patients with HP induced by LA typically have mild respiratory symptoms and sometimes normal CXR findings, their conditions might remain undiagnosed. However, the chest HRCT images showed the typical subacute phase of HP.

Adult↗

PubMed2001

A case of effusive-constrictive pericarditis after cardiac surgery.

A 60-year-old woman who had undergone repair of an atrial septal defect was readmitted to the hospital with dyspnea, abdominal distention, and leg edema 31 months after surgery. An echocardiogram demonstrated massive pericardial effusion. Cardiac catheterization revealed elevation and equilibrium of the 4-chamber diastolic pressure and a dip-and-plateau pattern in the right and the left ventricular pressures. Despite removal of pericardial fluid by pericardiocentesis, the findings and symptoms did not improve. The patient underwent both parietal and visceral pericardiectomy after which striking hemodynamic and symptomatic improvement occurred. Effusive-constrictive pericarditis is uncommon but should be considered in patients with refractory heart failure and massive pericardial effusion showing no improvement after removal of pericardial fluid.

Aged↗

PubMed2001

[Development of new hydrophilic catheter kit for self-catheterization: study in pediatric cases].

PURPOSE: To increase the management of self-catheterization in children of school age, a catheter kit consisting of hydrophilic catheter and a packet containing sterilized water was developed. We evaluated the lubricating characteristic and clinical efficacy of this new catheter kit. MATERIALS AND METHODS: The catheter kit used in the study was a pocket-size plastic container in which a polyurethane catheter coated with hydrophilic polymer and a packet containing sterilized water were packed in combination. The lubricating characteristic of catheter was assessed by the measurement of friction value. For clinical assessment, male children aged over 6 years old who were doing self-catheterization at 17 medical institutions nationwide were selected as the subjects. The 32 children who had given informed consent (mean age: 11.6 years old) were asked to use the catheter kit continuously for 1 week. The results were investigated by a questionnaire survey in which the assessment before and after the use was expressed in scores. At the same time, urinalysis and urine culture were examined. RESULTS: The friction value of hydrophilic catheter was equivalent to or less than that observed by applying a lubricant to the conventional catheter. The comparison of conventional catheter with the kit indicated significantly higher scores (assessment in 5 grades expressed in scores) for the portability and operability of the kit. Though there was no significant difference in the ease of insertion between the two catheters, there were several comments that the kit got stuck in the urethra when it was withdrawn. The global assessment gave a significantly higher score to the kit and 30 (94%) of the 32 children wanted to use the kit continuously. No increase in hematuria which caused a clinical problem or no new apparent urinary tract infection occurred after the use of the kit. CONCLUSIONS: Compared with the conventional catheter, the hydrophilic catheter kit highly satisfied a large number of children at the time of self-catheterization. Depending on the condition of children, the kit is considered useful for continued self-catheterization for a long term.

Child↗

PubMed2001

[Generalized tonic-clonic seizure induced by propofol in a patient with epilepsy].

A 47-year-old female was scheduled for ulnar osteotomy under general anesthesia combined with brachial plexus block. She had a history of symptomatic epilepsy due to subarachnoid hemorrhage. Immediately after giving 100 mg bolus of propofol to the patient, she developed generalized convulsion similar to a grand mal. The seizure was suppressed by the administration of thiamylal. After that no further convulsive attack occurred. Although it has been known that propofol has anticonvulsive properties, there have been several reported cases of seizure following the administration of propofol. Further studies are needed to clarify the mechanism of seizure induced by propofol in the patients with epilepsy.

Anesthesia, General↗

PubMed2001

[Two cases of acute eosinophilic pneumonia--analyses of cytokines in BALF before and after treatment].

Acute eosinophilic pneumonia (AEP) has been well recognized as sudden onset respiratory failure characterized by an increased eosinophilic cell count in the bronchoalveolar lavage fluid (BALF). Although several lines of research have demonstrated that the Th2 cytokine network is likely to play a pivotal role in the development of AEP, that mechanism has not been clearly understood yet. Previous reports published in Japan demonstrated that the BALF CD4/CD8 ratio in patients with AEP ranged between 1.1 and 5.8. In this report, we describe 2 cases of AEP in which the CD4/CD8 ratios were 0.3 and 7.8 when present. We measured IL-4, IL-5, IL-10 and IFN gamma in the BALF before and after treatment in these patients. IL-5 decreased drastically after the treatment phase, while the other cytokines did not change much. We concluded that the IL-5 concentration in the BALF is probably related to the development of AEP. In addition, we also speculated that the CD4/CD8 ratio in BALF from patients with AEP may be affected whether a patient has an atopic background or not.

Acute Disease↗

PubMed2001

Collaborated surgical works (surgical planning) in virtual space with tactile sensation between Japan and Germany.

Surgeons in Japan and Germany applied tele-virtual surgery and a force feedback device during a hepatectomy simulation. Using this system, surgeons in each country were able to perform various surgical maneuvers upon the same patient. They palpated abdominal skin, made electrical scalpel incisions and widened the incision line by using surgical tools in virtual space. While surgeons performed a virtual operation, the force feedback device conveyed tactile sensations. In each location, the force feedback devices and two graphic workstations of equal capability were employed. As each workstation communicated only event signals through an ISDN (64 Kb) line, it was possible to obtain real time tele-virtual surgery without a large capacity communication infrastructure.

Computer Graphics↗