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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 91 records · Page 5Linked to original sources
PubMed2001

Low power diode laser treatment using indocyanine green for eradication of esophageal varices.

BACKGROUND AND STUDY AIMS: Endoscopic variceal ligation (EVL) is an alternative to sclerotherapy for the treatment of esophageal varices, but is associated with higher rates of recurrence and subsequent bleeding than sclerotherapy. To prevent recurrence of varices after EVL, we have developed a low-dose diode laser therapy combined with the injection of indocyanine green, which allows enhanced tissue absorption of the laser beam selectively around varices. In this study we investigated the efficacy and safety of this technique. PATIENTS AND METHODS: Eight patients with F2 or F3 esophageal varices were enrolled. At 1 week after EVL, indocyanine green solution (1 mg/ml) was injected submucosally around the remaining varices. A diode laser (power 10 watts) was applied to the surface from the esophagogastric junction to 5 cm above it. The spot size was kept to 5 mm in diameter. RESULTS: Laser irradiation was performed safely, without bleeding from the varices, or perforation. There were no major complications. Endoscopy 1 month later showed F0 forms in seven patients, F1 in one patient, and no red color sign in any patient. No recurrence of varices has been observed in any of the patients during the follow-up period of at least 12 months. CONCLUSION: This technique may provide a simple, safe and effective procedure, as an additional treatment to EVL, for the prevention of recurrence of esophageal varices.

Adult↗
PubMed2001

Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy.

BACKGROUND: EUS-guided fine needle aspiration (EUS-FNA) is a highly accurate method of detecting malignant lymphadenopathy. The optimal methods for performing EUS-FNA to maximize sensitivity and to minimize the number of needle passes necessary are unknown. This is a report of the results of a prospective randomized controlled trial to determine the effect of suction, the site of FNA (edge or center of lymph node), and the method of preparation of cytologic specimens on accuracy, number of needle passes needed, and specimen quality. METHODS: Consecutive patients with lymphadenopathy detected by EUS underwent FNA. Each lymph node was sampled with or without suction and from the edge or center in a 2 x 2 factorial design. The samples were expressed onto slides for cytology, and the residual material in the needle was analyzed by the cytospin-cellblock technique. Each aspirate was individually characterized for a diagnosis of malignancy, cellularity, and bloodiness. RESULTS: Forty-three patients with a total of 46 lymph nodes were evaluated. The final lymph node diagnosis was benign in 22 (48%), "suspicious for malignancy" in 6 (13%), and malignant in 18 (39%). The use of suction was associated with an increase in the cellularity of the specimen, but did not improve the likelihood of obtaining a correct diagnosis (OR 1.52: 95% CI [0.81, 2.85]). Samples obtained with suction were of worse quality because of excessive bloodiness (OR 4.7: 95% CI [1.99, 11.24]). Aspiration from the edge of the lymph node (compared with the center) did not increase the likelihood of a correct diagnosis (OR 1.16: 95% CI [0.42, 3.21]). For 78% of malignant lymph nodes, the correct diagnosis was obtained on the first needle pass and for 100% by the third pass. Cytospin-cellblock methods did not add any additional diagnostic information compared with direct smear cytology. CONCLUSIONS: The traditional method of applying suction during EUS-FNA does not improve diagnostic accuracy and worsens specimen bloodiness compared with FNA without suction. The site of FNA within the lymph node does not affect accuracy. When EUS-FNA is necessary, our recommendation is up to 3 FNAs without suction from the most convenient and safe location within abnormal-appearing lymph nodes.

Biopsy, Needle↗
PubMed2001

The utility of EUS and EUS-guided fine needle aspiration in detecting celiac lymph node metastasis in patients with esophageal cancer: a single-center experience.

BACKGROUND: The aims of this study were to determine the utility of EUS and EUS-guided fine needle aspiration (EUS-FNA) in the detection and confirmation of celiac lymph node metastasis in patients with esophageal cancer and to define EUS features predictive of celiac lymph node metastasis in these patients. METHODS: The records of 211 patients with esophageal cancer who underwent EUS staging were reviewed. The operating characteristics of EUS were determined in patients where either surgery, EUS-FNA of a celiac lymph node, or both were performed (n = 102). The association between selected variables and the presence of celiac lymph node metastasis was evaluated by univariate and multivariable analyses. RESULTS: EUS in 48 patients provided a true-positive diagnosis of celiac lymph node involvement, a false-positive and false-negative result, respectively, in 6 and 14 patients, and a true-negative diagnosis in 34 patients. The sensitivity of EUS in detecting celiac lymph node was 77% (95% CI [67, 88]), specificity 85% (95% CI [74, 96]), negative predictive value 71% (95% CI [58, 84]), and the positive predictive value 89% (95% CI [81, 97]). EUS-FNA was performed in 94% (51/54) of patients with celiac lymph nodes. The accuracy of EUS-FNA in detecting malignant celiac lymph nodes was 98% (95% CI [90, 100]). Advanced T-stage, the need for dilation, detection of peritumoral lymph nodes, and black race were associated with celiac lymph node involvement. In multivariable analysis, advanced T-stage was the strongest predictor of celiac lymph node involvement. CONCLUSION: EUS and EUS-FNA are highly accurate in detecting and confirming celiac lymph nodes metastasis. Depth of tumor invasion as assessed by EUS is a strong predictor of celiac lymph node metastasis in patients with esophageal cancer.

Adenocarcinoma↗
PubMed2001

Overexpression of lymphangiogenic growth factor VEGF-C in human pancreatic cancer.

Vascular endothelial growth factor C (VEGF-C) is a lymphangiogenic polypeptide that has been implicated in cancer growth. In this study, we characterized VEGF-C expression in cultured human pancreatic cancer cell lines and determined whether the presence of VEGF-C in human pancreatic cancers is associated with clinicopathologic characteristics. VEGF-C mRNA transcripts were present in all five tested cell lines (Capan-1, MIA-PaCa-2, PANC-1, COLO-357, and T3M4). Immunoblotting with a highly specific anti-VEGF-C antibody revealed the presence of VEGF-C protein in all the cell lines. Northern blot analysis of total RNA revealed an approximately 2.2-fold increase in VEGF-C mRNA transcript in the cancer samples compared with the normal pancreas. Immunohistochemical analysis confirmed the expression of VEGF-C and its receptor flt-4 in the cancer cells within the tumor mass. Immunohistochemical analysis of 51 pancreatic cancer tissues revealed the presence of strong VEGF-C immunoreactivity in the cancer cells in 80.4% of the cancer tissues. The presence of VEGF-C in these cells was associated with increased lymphatic vessels invasion and lymph node metastasis, but not with decreased patient survival. These findings indicate that VEGF-C and its receptor are commonly overexpressed in human pancreatic cancers and that this factor may contribute to the lymphangiogenic process and metastasis in this disorder.

Blotting, Northern↗
PubMed2001

Relationship between esophageal dysfunction and neuropathy in diabetic patients.

OBJECTIVE: Few studies have compared esophageal dysfunction with diabetic neuropathy, and their relationship is not yet clear. The aim of this study was to investigate the relationship between esophageal function and diabetic neuropathy. METHODS: A total of 59 patients with type 2 diabetes were studied. Long-term ambulatory esophageal pH and motility monitoring were performed. The motor nerve conduction velocity (MCV) and coefficient of variation of R-R intervals (CVRR) were also examined. RESULTS: The 59 patients were classified into four groups: group 1 consisted of patients with both diabetic autonomic neuropathy (DAN) and diabetic motor neuropathy (DMN), group 2 had DMN alone, group 3 had DAN alone, and group 4 had neither DAN nor DMN. In pH monitoring, differences were observed among the four groups in DeMeester score, total number of acid reflux episodes, and % time pH < 4 (p < 0.05). A correlation was observed between % time pH < 4 and MCV; however, no correlation with CVRR was observed. In motility monitoring, differences were observed among the four groups in amplitude of peristaltic waves (p < 0.001), rising velocity of peristaltic waves (p < 0.01), and percentage of effective peristalsis (p < 0.01). A correlation was observed between esophageal motility and MCV; however, no correlation with CVRR was observed. CONCLUSIONS: Esophageal motility disorder and abnormal acid reflux were related to DMN in diabetic patients. A significant correlation was found between esophageal dysfunction and MCV. However, no significant correlation was found between esophageal dysfunction and CVRR.

Aged↗
PubMed2001

Improvement in site-specific intestinal absorption of furosemide by Eudragit L100-55.

Furosemide (frusemide) is a weakly acidic diuretic drug. Its absorption is poor and variable, in part due to its restricted sites of absorption, mainly the stomach. The narrow absorption window of this drug can be explained by pH partition theory. The purpose of this study was to investigate the feasibility of widening the absorption window of furosemide by controlling the pH in distal portions of the gastrointestinal tract with officially used additives. Methacrylate copolymer (Eudragit L100-55), hydroxypropylmethylcellulose phthalate (HP-55) and hydroxypropylmethylcellulose acetate succinate (AS-MF) were selected as additives. The pH of suspensions of these additives was about 4, and the pH was adjusted to about 6-7 by the addition of NaOH. The Eudragit L100-55 suspension was found to be the most resistant to NaOH titration. When Eudragit L100-55 was used in an in-situ ileal loop experiment in rats, the pH of the intestinal contents was significantly reduced, from 7.9+/-0.1 to 5.7+/-0.1, and the plasma concentration of furosemide 15 min after administration was about 3 times higher than that in controls, 1.81+/- 0.42microg mL(-1) vs 0.63+/-0.08 microg mL(-1). However, the plasma concentration of [14C] mannitol was not changed by the co-administration of Eudragit L100-55. Furthermore, the AUC of furosemide was significantly increased by a factor of about 1.6 relative to that in controls by the co-administration of Eudragit L100-55, to 21.4+/-4.0 microg h mL(-1) from 13.3+/- 3.9 microg h mL(-1), and the gastrointestinal pH in the midgut and ileum was significantly reduced, with most of the furosemide remaining in these segments at 2 h following the oral administration of furosemide with Eudragit L100-55 to rats. These findings clearly demonstrate that the addition of Eudragit L100-55 can increase the absorption of furosemide in distal portions of the gastrointestinal tract. In conclusion, it is feasible to widen the absorption window of furosemide by controlling the pH in distal portions of the gastrointestinal tract by the co-administration of Eudragit L100-55.

Animals↗
PubMed2001

Insecticidal and neural activities of candidate photoaffinity probes for neonicotinoid binding sites.

Photoreactive derivatives of imidacloprid and its nitromethylene analogue were synthesized as candidate photoaffinity probes for identifying the amino acid residues of nicotinic acetylcholine receptors (nAChRs) that interact with the neonicotinoid insecticides. When the candidate probes were injected into American cockroaches, the nerve cord neural activity initially increased, then ceased and death of the insect followed. Both the nerve cord and toxicity were enhanced by changing the photoreactive substituent from the para position to the meta position on the spacer benzyl moiety. When tested on a Drosophila SAD/chicken beta2 hybrid, recombinant nAChR expressed in Xenopus oocytes, the nitromethylene candidate probes showed agonist activity similar to that previously observed for imidacloprid.

Anabasine↗
PubMed2001

Expression and properties of human liver beta-ureidopropionase.

A cDNA encoding beta-ureidopropionase (BUP) was isolated from a human liver cDNA library, expressed in E. coli, and purified from the culture extract. The 2,006 bp cDNA contained a 1,152 bp open reading frame encoding a protein of 384 amino acids with a molecular weight of 43,165 Da. The subunit molecular weight of the enzyme expressed was about 43,000 Da. The enzyme was inhibited by 1 mM propionate, but not by 10 mM beta-alanine. Chemical analysis of the purified human BUP showed 0.54 zinc atoms per subunit, and the sequence of BUP cDNA contained one putative zinc-binding site motif. The purified enzyme had a pI of 5.65, and exhibited positive cooperativity with N-carbamoyl-beta-alanine as the substrate with a Hill coefficient 2.0. These properties of human BUP, except the inhibition by beta-alanine, were similar to the rat liver purified enzyme. Beta-alanine inhibits rats BUP activity. The complex regulatory function and the negative cooperative mechanism of BUP by beta-alanine have been observed in rats. This kind of mechanism may not exist in humans, because beta-alanine did not inhibit human BUP.

Amidohydrolases↗
PubMed2001

[Neuroimaging and electrophysiological study in epilepsy].

There exist various morphological and biochemical changes closely associated with electrophysiological phenomena which cause epileptic seizures in the brains of epilepsy patients. Recent developments in investigation methods, not only electrophysiological(EEG and MEG), but also neuroimaging involving morphological imaging(CT and conventional MRI) and functional imaging(SPECT, PET, functional MRI and MRS) is able to demonstrate these changes. SPECT and PET can particularly clarify the changes of cerebral blood flow and glucose metabolism between interictal and ictal periods. In our experience of 423 patients who underwent epilepsy surgery for intractable seizures, these interventions provide important information to identify the epileptogenic foci. However, in practice, discordance in the results of these presurgical evaluations is recognized, and invasive intracranial recordings are needed in such cases. These problems in diagnosis were shown especially in patients with mesial temporal sclerosis and focal cortical dysplasia. To detect an epileptogenic focus more clearly, a combination of morphological and functional findings, new functional imaging such as neurotransmitter receptor imaging, EEG-triggered or neuropharmacological functional MRI, as well as, statistical parametric analysis may be needed.

Electroencephalography↗
PubMed2001

Deletions on chromosome 8p22 may predict disease progression as well as pathological staging in prostate cancer.

PURPOSE: A recent report demonstrated that the deletion of chromosome 8p22 could predict disease progression in stage III (capsular penetrating) prostate cancer. We studied if the status of chromosomal deletions of 8p22 could reflect pathological stage as well as patient prognosis, thereby serving as a diagnostic tool to optimize the treatment strategy in prostate cancer. EXPERIMENTAL DESIGN: A total of 97 patients (41 Japanese and 56 Swedish) were studied by the fluorescence in situ hybridization technique. Seventy-seven patients (23 pT2, 18 pT3, and 36 pN+ tumors) underwent surgery (radical prostatectomy or lymph node dissection). The specimens were prepared by touch biopsy. From another 20 cases, fine-needle aspiration biopsies were obtained. RESULTS: 8p22 deletions were detected in 47 (61%) and 11 (55%) specimens of 77 touch biopsies and 20 fine-needle aspiration biopsies, respectively. No significant difference was found in the frequency of 8p22 deletion between different preparations of specimens, as well as between different races (Japanese versus Swedish). The frequency of 8p22 deletion was statistically higher in patients with pT3 or more than in those with pT2 (P < 0.01). Disease progression was evaluated in 57 patients. The Cox proportional hazards model revealed 8p22 deletion to be the strongest parameter to predict disease progression (hazards ratio = 5.75; P = 0.0001). CONCLUSIONS: Studies on chromosomal deletions of 8p22 by fluorescence in situ hybridization technique may serve as a genetic marker to optimize the treatment strategy in patients with prostate cancer to the optimal treatment.

Aged↗