Biomedical subjects

T Yamada

Publications and source records attributed to T Yamada.

At least 199 records · Page 11Linked to original sources

PubMed2001

Characterization of nociceptive responses and spinal releases of nitric oxide metabolites and glutamate evoked by different concentrations of formalin in rats.

A comparison was made of spontaneous nociceptive behaviors elicited by subcutaneous injection of formalin (0.5-10.0%) into the plantar or dorsal surface of the right hindpaw in rats. In the present study, we also examined the effect of paw formalin injection on the release of nitric oxide (NO) metabolites (nitrite/nitrate) and glutamate from the spinal cord in anesthetized rats using a dialysis probe placed in the lumbar subarachnoid space. Two distinct quantifiable behaviors indicative of pain were identified by formalin injected into both regions of the paw. There were no significant alterations in the number of flinches during the early and late phases induced by different regions of formalin injection. However, the early phase licking/biting activity evoked by formalin injection into the plantar surface of the paw was significantly higher than that evoked by formalin injected into the dorsal region. The maximum effect in the early and late phases was produced by 5.0% formalin injection into the dorsal and plantar paw. At a higher concentration (10.0%) of formalin, nociceptive behavioral responses were decreased except for the late phase flinching when injected into the dorsal paw. Injections of formalin (5.0%) into both regions of the paw evoked a biphasic spinal release of nitrite/nitrate with a significant increase during the early phase (0-10 min) and the late phase (30-80 or 90 min). A higher concentration of formalin (10.0%) failed to produce a clear-cut release of nitrite/nitrate. A significant increase of glutamate was observed in the 0-10 min samples obtained after injection of formalin (5.0%) into the plantar and dorsal surface of the paw, whereas 0.5 and 10.0% formalin induced no substantial release. These results suggest that 5.0% formalin should be used when studying antinociceptive activity of NO- and N-methyl-D-aspartate-related compounds in the formalin test in rats. Formalin injection into the plantar surface of the paw might prove to be useful for evoking the licking/biting response, particularly in the early phase.

Animals↗

PubMed2001

Arterial remodeling influences the development of intimal hyperplasia after stent implantation.

OBJECTIVES: We examined whether preinterventional arterial remodeling influenced the interventional results after stenting. BACKGROUND: Arterial remodeling is seen in atherosclerotic lesions, and it may play an important role in the early stage of atherosclerosis. METHODS: We examined 113 lesions that underwent elective stenting using tubular slotted stents under intravascular ultrasound guidance. The lesions were divided into three groups--adequate, intermediate and inadequate remodeling group--according to preinterventional arterial remodeling. The patients were subjected to coronary angiography and intravascular ultrasound evaluation on average 6.4 months after stenting. RESULTS: At baseline and immediately after stenting, there were no differences in quantitative angiographic analysis among remodeling groups. However, the plaque cross-sectional area (CSA) in the minimal lumen CSA at preintervention and intimal hyperplasia CSA at follow-up were significantly larger in the adequate remodeling group than in the inadequate remodeling group. The restenosis rate of stenting for the lesions with inadequate arterial remodeling was very low (9.4%). A significant positive correlation was found between preinterventional plaque CSA and intimal hyperplasia CSA at follow-up (r = 0.47, p < 0.0001). Moreover, remodeling index significantly correlated with relative intimal hyperplasia CSA (r = 0.28, p < 0.01). CONCLUSIONS: Preinterventional arterial remodeling influenced the development of intimal hyperplasia after stenting.

Aged↗

PubMed2001

Corneal sensation after correction of myopia by photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: To compare the effects of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on corneal sensation. SETTING: Ohshima Hospital of Ophthalmology, Fukuoka, Japan. METHODS: Corneal sensation was measured with a Cochet-Bonnet esthesiometer in 35 patients before and 3 days, 1 week, and 1 and 3 months after correction of myopia by PRK (22 patients) or LASIK (13 patients). RESULTS: After PRK, corneal sensitivity was decreased slightly at 3 days, began to recover at 1 week, and returned to preoperative values at 3 months; none of the changes was statistically significant (P >.05). After LASIK, corneal sensation was significantly decreased at 3 days, 1 week, and 1 month; it recovered slightly at 3 months, although it remained significantly less than preoperatively. CONCLUSIONS: Laser in situ keratomileusis was associated with a negative effect on corneal sensation, which was markedly greater than the effect with PRK and was evident for at least 3 months after surgery.

Adolescent↗

PubMed2001

Transient translocation of hemidesmosomal bullous pemphigoid antigen 1 from cytosol to membrane fractions by 12-O-tetradecanoylphorbol-13-acetate treatment and Ca2+-switch in a human carcinoma cell line.

We previously showed that 12-O-tetradecanoylphorbol-13-acetate (TPA) and Ca2+-switch from low (0.07 mM) to normal (1.87 mM) concentration in culture medium, which were also linked to activation of protein kinase C (PKC), lead to phosphorylation of 180 kDa-bullous pemphigoid antigen (BPAG) 2, but not of 230 kDa-BPAG1, and possibly to its disassembly from hemidesmosomes in a human squamous cell carcinoma cell line (DJM-1). In this study, we examined the effects of TPA and Ca2+-switch on intracellular localization of BPAG1 by immuno-blotting and immuno-fluorescence microscopy with monoclonal antibodies to the antigen after sub-cellular fractionation. In DJM-1 cells cultured in low Ca2+ medium, BPAG1 was detected as phosphate buffered saline-soluble (cytosolic), Triton X-100 soluble (roughly membrane-associated) and Triton X-100 insoluble (cytoskeleton-bound) forms, whereas in normal Ca2+-grown cells only as cytosolic and cytoskeleton-bound forms. In normal Ca2+-cultured cells, TPA (50 nM) caused a complete translocation of BPAG1 from cytosol to membrane fractions within 10 min, that was inhibited by pretreatment with H7 (a selective PKC inhibitor) at 40 microM. After 30 min and 4 h of TPA-treatment, BPAG1 was exclusively detected in cytoskeleton fractions. Morphologically, immuno-fluorescence microscopy showed that treatment caused a marked reduction of BPAG1 from the cytoplasm and generated a linear pattern at cell-cell contacts, suggesting translocation of BPAG1 from the cytosol to the plasma membrane. In contrast, the Ca2+-switch from low to normal caused a prominent increase of BPAG1, both in cytosolic and membrane-associated forms after 4 h, that was inhibited both with H7 and cycloheximide (an inhibitor of protein synthesis) at 70 microM, suggesting a role for PKC and BPAG1 synthesis in these Ca2+-induced effects. These results suggest that TPA and Ca2+-switch induced BPAG1 translocation to membrane fractions possibly mediated by PKC-activation. Furthermore, whereas TPA affects the redistribution of BPAG1 among their pools without inducing their synthesis, Ca2+-switch induces both membrane translocation and synthesis of BPAG1, suggesting involvement of signaling other than PKC pathways in control of BPAG1 synthesis.

Autoantigens↗

PubMed2001

Prognostic factors in patients with resected pathologic (p-) T1-2N1M0 non-small cell lung cancer (NSCLC).

OBJECTIVES: To clarify prognostic factors in resected pathologic (p-) T1-2N1M0 non-small cell lung cancer (NSCLC). METHODS: A total of 95 consecutive patients who underwent complete tumor resection and mediastinal dissection for pT1-2N1M0 NSCLC between 1976 and 1997 were retrospectively reviewed. p53 status and proliferative activity were evaluated immunohistochemically. RESULTS: The extent of N1 stations and p53 status proved to be significant prognostic factors. The 5-year survival rate for tumor without hilar node (#10) involvement was 66%, significantly higher than that for tumor with #10 involvement (39%, P<0.01). The 5-year survival rate for tumor with aberrant p53 expression was 37%, significantly lower than that for tumor without aberrant p53 expression (74%, P<0.01). There proved to be no significant difference in the prognosis between pT1 disease and pT2 disease; the 5-year survival rates for pT1 and pT2 diseases were 62 and 56%, respectively. Age, gender, performance status, grade of tumor differentiation, histological type, or proliferative activity were not significant factors. Multivariate analysis of prognostic factors using Cox's proportional hazard model confirmed these results. CONCLUSIONS: Involvement of the hilar node and aberrant p53 expression were significant factors to predict a worse prognosis in resected T1-2N1M0 NSCLC.

Biomarkers, Tumor↗

PubMed2001

Intraarterial low-dose cisplatin via an indwelling port and concurrent radiotherapy for invasive bladder cancer.

Thirteen patients with invasive bladder cancer who had residual tumor after transurethral resections, were treated with consecutive intraarterial (IA) cisplatin (15 mg/d; total, 150 mg) and concurrent radiation (1.8 Gy/d; total, 30.6 Gy). All patients received unilateral or bilateral placement of vascular access devices (VAD) to perform daily cisplatin infusion after alteration of intrapelvic blood flow by coil embolizations. Tumor response was evaluated by transurethral biopsy 2 weeks after treatment. Complete response, defined as no viable tumor cell in the biopsy specimen, was achieved in seven patients (54%). After a median follow-up of 30 months (range, 12-48 months), 10 patients (77%) were alive, five (38%) of whom had no recurrence. Two cancer-related deaths were observed. All complete response cases survived with a median follow-up of 35 months (range, 25-48 months). Cause-specific and disease-free survival rates at 4 years were 85% and 28%, respectively. The regimen was well-tolerated, with no dose-limiting toxic events. There were no VAD-related complications. Consecutive IA low-dose cisplatin and concurrent radiation may be an acceptable alternative treatment for patients with bladder cancer who are not suitable for systemic chemotherapy. The use of a VAD contributed to successful consecutive IA infusions.

Aged↗

PubMed2001

Results of duct-to-mucosa pancreaticojejunostomy for pancreaticoduodenectomy Billroth I type reconstruction in 100 consecutive patients.

BACKGROUND: This study retrospectively analyzed 100 consecutive patients who underwent pancreaticoduodenectomy (PD) and pylorus-preserving PD (PPPD) with a Billroth I type reconstruction and pancreaticojejunostomy by duct-to-mucosal anastomosis using a continuous running suture. STUDY DESIGN: Seventy patients underwent PD and 30 patients PPPD for pancreatic cancer in 33, bile duct cancer in 28, ampullary or duodenal tumor in 22, chronic pancreatitis in 8, and other gastrointestinal cancer in 9. Postoperative pancreatic anastomotic leakage was diagnosed from skin excoriation around the drain site, and was defined as a high concentration of amylase in drainage fluid or leakage demonstrated on x-ray. RESULTS: The mortality rate was 2% overall (2.8% in PD, 0% in PPPD). The morbidity rate was 23% overall (12.8% in PD, 46.7% in PPPD). Pancreatic anastomotic leakage was 4.0% overall (2.8% in PD, 6.7% in PPPD).. The incidence in the ampullary or duodenal tumors was 9.1% overall (0% in PD, 14.3% in PPPD). Biliary leakage occurred in four patients, 4.0% overall (4.3% in PD, 3.3% in PPPD), intraabdominal hemorrhage in 2% (2.8% in PD, 0% in PPPD), and lethal anastomotic leakage in one patient, overall rate 1% (1.4% in PD, 0% in PPPD). Delayed gastric emptying had the highest morbidity and was seen exclusively in PPPD (39.3%). CONCLUSIONS: A simple continuous running suture and parachuting for duct-to-mucosal pancreaticojejunostomy makes pancreaticoduodenectomy a safe procedure, even in a Billroth I type reconstruction.

Anastomosis, Surgical↗

PubMed2001

Novel nitric oxide donor (FK409) ameliorates liver damage during extended liver resection with warm ischemia in dogs.

BACKGROUND: Nitric oxide attenuates ischemia-reperfusion injury by maintaining organ circulation through its actions as a vasoregulator, an inhibitor of platelet aggregation, and an attenuator of leukocyte adhesion. Otherwise, the harmful effects of enhanced nitric oxide production induced by inducible nitric oxide synthase mediate ischemia-reperfusion injury. FK409 has been characterized as a spontaneous nitric oxide donor. The aim of this study was to evaluate the effects of FK409 on extended liver resection with ischemia using a canine model. STUDY DESIGN: Adult mongrel dogs were subjected to 60 minutes of warm ischemia by partial inflow occlusion. After reperfusion the nonischemic lobes were resected and the remnant liver function was evaluated. The dogs were divided into two groups: the control group (n = 7) and the FK409 group (n = 6), which was given FK409 through the portal vein. RESULTS: The hepatic tissue blood flow, serum liver enzymes levels, and serum endothelin-1 level after reperfusion were significantly better in the FK409 group than in the control group. Electron microscopy demonstrated that endothelial cells and Ito cells were well-preserved in the FK409 group. The 3-day survival rate was statistically better in the FK409 group (67%) than in the control group (14%). CONCLUSIONS: FK409 appears to have protective effects during extended liver resection with ischemia.

Animals↗

PubMed2001

Laparoscopic-assisted removal of a large urachal cyst.

A 48-year-old woman was seen because of an abdominal tumor. Laparoscopy was performed for diagnosis and treatment. A large cystic mass was hanging from the anterior abdominal wall and was removed with laparoscopic assistance. Histologic examination revealed a urachal cyst. (J Am Assoc Gynecol Laparosc 8(1):159-160, 2001)

Female↗

PubMed2001

Laparoscopic-assisted surgery for benign ovarian cyst in a young girl.

A 7-year-old girl was admitted to our hospital because of sudden lower abdominal pain and vomiting. Emergency laparoscopy and cystectomy were performed, with a diagnosis of torsion of an ovarian cyst. All manipulations were possible through a 2-cm incision in the abdominal wall.

Abdominal Pain↗

PubMed2001

Sensitive determination of midazolam and identification of its two metabolites in human body fluids by column-switching capillary high-performance liquid chromatography/fast atom bombardment-mass spectrometry.

Midazolam is a benzodiazepine and is widely prescribed for preanesthesia or general anesthesia. Overdose or intoxication cases of midazolam have been reported. In Japan, smuggled midazolam tablets could be involved in some criminal cases. Midazolam and its two metabolites were extracted by the solid-phase extraction method using Bond Elut SCX cartridges. The compounds were analyzed by on-line capillary high-performance liquid chromatography/fast atom bombardment-mass spectrometry. Midazolam and its two metabolites were well separated on the chromatogram, and each mass spectra gave [M+H](+) ion as a base peak. Deuterium-labeled midazolam was synthesized as an internal standard; it has enabled precise and reproducible quantitation of midazolam in blood samples. The calibration curve showed excellent linearity in the range of 2-200 ng/ml in spiked serum. The detection limit was 300 pg/ml (signal-to-noise ratio=3). The whole blood and urine samples from the victim of a homicide case were analyzed, and the midazolam concentration in the whole blood was estimated to be 163 ng/ml. The present method should be useful in clinical and forensic toxicology, because of its high sensitivity and specificity.

Journal Article↗

PubMed2001

A controlled study of repetitive transcranial magnetic stimulation as a treatment of depression in the elderly.

Rapid transcranial magnetic stimulation (rTMS) applied to the left dorsal lateral frontal cortex has been shown to produce antidepressant effects. Older depressed patients, however, in one study showed a lower response rate than younger patients. The current study examined treatment response in 20 depressed, treatment-refractory patients (mean age 60.7 +/- 9.8 years) given five sessions of rTMS at 20 Hz for 2 seconds over 20 trains at 80% of motor threshold or identical placebo stimulation, after patients had been withdrawn from their antidepressants. There were no significant differences in Hamilton Depression Scale scores either before or after treatment at 7 days' follow-up. There were three responders to active treatment and three to sham treatment and responders had significantly greater frontal lobe volume than nonresponders (p = .03). These findings suggest that the stimulation parameters used in this study were probably insufficient to produce treatment response and that frontal atrophy may interfere with the effectiveness of rTMS.

Aged↗

PubMed2001

Identification, determination, and biological evaluation of a novel styrene trimer contained in polystyrene food containers. 2.

An unidentified styrene trimer (ST) isolated from the acetonitrile extract of polystyrene (PS) food containers was characterized as (1S*,6R*,7S*,8S*,11R*)-6,11-diphenyltricyclo[6,2,2,0(2,7)]dodeca-2,9-diene. The content and migration of this compound in PS food containers were determined by GC-MS (SIM). Furthermore, an endocrine-disrupting effect was tested using in vitro and in vivo assays of the compound. In conclusion, it seems that the compound does not present the effect.

Animals↗

PubMed2001

Clarithromycin resistance, but not CYP2C-19 polymorphism, has a major impact on treatment success in 7-day treatment regimen for cure of H. pylori infection: a multiple logistic regression analysis.

Mutations in the gene encoding the CYP2C-19 enzyme for PPI metabolism have been shown to enhance the chance for a cure in a H. pylori-positive patients using a two-week dual-therapy regimen involving omeprazole and amoxicillin. However, the impact of CYP2C-19 genetic polymorphism on eradication rates of a one-week triple-therapy regimen has not been examined. In this cohort study, 156 H. pylori-positive peptic ulcer or NUD patients who presented to our university hospital were recruited. They were treated by one-week omeprazole-amoxicillin-clarithromycin therapy. Host and bacterial predictive factors including H. pylori susceptibility and CYP2C-19 genotyping, as well as cure rate for H. pylori infection, were studied. Cure rate was 85.9% (95% CI: 79-91%) on an intent to treat (ITT) basis. By multiple logistic regression analysis, only clarithromycin resistance had a significant impact on treatment success (odds ratio 28.7: 95% CI: 6-172). CYP2C-19 genetic polymorphism was not associated with a significant change in cure rate. These observations indicate only clarithromycin susceptibility, not CYP2C-19 polymorphism, has a major impact on the treatment success when using a seven-day OAC H. pylori treatment regimen.

Amoxicillin↗

PubMed2001

Inhibitory effect of sorbitol on sugar metabolism of Streptococcus mutans in vitro and on acid production in dental plaque in vivo.

This study was conducted to find out whether sorbitol inhibits the sugar metabolism of Streptococcus mutans in vitro and the acid production in dental plaque in vivo. S. mutans NCIB 11723 was anaerobically grown in sorbitol-containing medium. The rate of acid production from sugars was estimated with a pH stat. The rate of acid production from glucose or sucrose was not changed at various concentrations of oxygen. By the addition of sorbitol to sugar, however, the acid production was decreased with increasing levels of oxygen. Intracellular NADH/NAD+ ratio and (dihydroxyacetone-phosphate+glyceraldehyde-phosphate)/3-phosphoglycerate ratio were high whenever the acid production was inhibited by sorbitol. Sorbitol also inhibited the acid production in dental plaque in vivo. These results suggest that the increased NADH/NAD+ ratio during sorbitol metabolism through the inactivation of pyruvate formate-lyase by oxygen inhibited glyceraldehyde-phosphate dehydrogenase and then the acid production of S. mutans and the one in dental plaque.

Acetic Acid↗

PubMed2001

The time-course of acid excretion, levels of fluorescence dependent on cellular nicotinamide adenine nucleotide and glycolytic intermediates of Streptococcus mutans cells exposed and not exposed to air in the presence of glucose and sorbitol.

The aim of this study was to examine glucose and sorbitol metabolism in Streptococcus mutans cells exposed and not exposed to air at the coexistence of these compounds by measuring acid excretion, levels of fluorescence dependent on cellular NADH and glycolytic intermediates. An aliquot of bacterial cells grown under strictly anaerobic conditions (anaerobic cells) was exposed temporarily to air (aerobic cells). When glucose was added to the anaerobic cells metabolizing sorbitol, the acid excretion was increased. The level of NADH decreased initially and then increased to the higher plateau level than that during glucose metabolism. The aerobic cells neither metabolized sorbitol nor contained glycolytic intermediates. However, 2 min after glucose was added in the presence of sorbitol, the acid excretion was started slowly and the intermediates appeared. The level of NADH was decreased at first and then increased. These results suggested that the anaerobic S. mutans cells metabolized glucose and sorbitol simultaneously, and that in the presence of sorbitol the aerobic cells could start to metabolize glucose 2 min after glucose was added, as the intermediates (phosphoenopyruvate potential) for the glucose transport were accumulated.

Acids↗

PubMed2001

Adult-onset hereditary sensory and autonomic neuropathy accompanied by anosmia but without skin ulceration.

We report a novel type of hereditary sensory and autonomic neuropathy (HSAN) with adult onset in a Japanese family. One male and 2 females of 6 siblings were affected. They developed anosmia initially at the ages of 20-50 years, followed by anhidrosis and sensory loss. Skin ulceration was absent. Both superficial and deep sensation were impaired in the most distal parts of all 4 limbs. Orthostatic hypotension was present in all patients. This is a unique subtype of HSAN distinct from the HSAN I-V described by Dyck.

Adult↗

PubMed2001

Seasonal changes of humoral and cellular immune responses to Japanese cedar (Cryptomeria japonica) pollen allergens in Japanese monkeys (Macaca fuscata) with pollinosis.

The natural occurrence of Japanese cedar [Cryptomeria japonica (CJ)] pollinosis has been reported in Japanese monkeys (Macaca fuscata). The present study was designed to investigate seasonal changes in immunological reactions to CJ pollen allergens in monkeys with CJ pollinosis. Blood samples were collected from six monkeys with CJ pollinosis before and after CJ pollen season. Seasonal changes in specific IgE and IgG to major allergens (Cry j 1 and Cry j 2) were observed before and after CJ pollen season. The humoral responses decreased significantly before CJ pollen and increased after CJ pollen season. Similar seasonal changes in peripheral blood mononuclear cells proliferative responses to CJ allergens were observed before and after CJ pollen season. These humoral and cellular immune responses might serve as a biomarker for assessing new immunotherapies for monkeys with pollinosis.

Allergens↗