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Biomedical subjects

M Matsukawa

Publications and source records attributed to M Matsukawa.

At least 19 recordsLinked to original sources

[Mediastinal emphysema after a punch on the back; report of a case].

A 19-year-old man was punched on the back, and anterior chest pain appeared about 3 hours after injury. The patient was consulted a physician complaining of anterior chest pain. On chest X-ray, mediastinal emphysema was suspected, and transferred to our hospital. Chest computed tomography (CT) revealed mediastinal emphysema. On esophageal radiography and bronchofiberscopy, no abnormal findings were detected. Conservative therapy was conducted, and symptoms had gradually improved. On the 8th hospital day, mediastinal emphysema was improved on chest CT. The patient was discharged on the 10th hospital day. The most frequent cause of mediastinal emphysema after trauma is traffic or downfall accident, and no report on this condition after the punch on the back was found.

Adult↗

Identification of adrenoceptor subtype-mediated changes in the density of synapses in the rat visual cortex.

Both serotonin and noradrenaline affect synapse formation and maintenance in the CNS. Although we previously demonstrated that serotonin regulates synaptic density via activation of serotonin(2A) receptor, it was still unclear which receptor subtype mediates the function of noradrenaline. In the present study we tried to identify the noradrenaline receptor (adrenoceptor) subtype, which could regulate the density of synapses in the rat visual cortex. Selective antagonists and/or agonists of adrenoceptor subtypes were administered to six weeks old rats. Changes in the density of axodendritic synapses were quantitatively examined in lamina I, where noradrenaline rather than serotonin is known to regulate the density of synapses. The alpha1 adrenoceptor antagonists (prazosin and 2-{[b-(4-hydroxyphenyl)ethyl]aminomethyl}-1-tetralone) decreased the number of synapses in a dose-dependent manner. In contrast, administrations of the alpha1-agonist (methoxamine) increased the density of synapses. The beta1 adrenoceptor antagonist (atenolol) had no effect on the density of synapses. The alpha2-antagonist (rauwolscine) increased synaptic density, whereas the beta2-antagonist (ICI-118,551) decreased synaptic density. Simultaneous treatments with the alpha1-antagonist and alpha1-agonist caused the alpha1-agonist to competitively block the effect of the alpha1-antagonist and recover the density of synapses to the control values. In addition, the alpha1-antagonist/agonist appeared to show a reverse effect on the changes in synaptic density following alpha2- or beta2-antagonist treatment by acting via the alpha1 receptor. Moreover, decreased synaptic density when a selective noradrenergic neurotoxin (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine) was counterbalanced by the alpha1-agonist. These data suggest that noradrenaline regulates the density of synapses in the rat visual cortex primarily via the alpha1 receptor subtype. Both serotonin(2A) and alpha1 receptors are known to couple with phospholipase C, which has been shown to increase intracellular calcium. It may help us to understand the underlying mechanisms for synaptic plasticity in the CNS.

Adrenergic alpha-Agonists↗

Cyclic tensile stretch stimulates the release of reactive oxygen species from osteoblast-like cells.

It is known that the excessive generation of reactive oxygen species (ROS) is a significant factor in tissue injury observed in many disease states. To determine whether extreme levels of mechanical stress applied to osteoblasts enhances ROS synthesis, we loaded cyclic tensile stretch on osteoblast-like HT-3 cells. Cyclic tensile stretch loaded on these cells clearly enhanced ROS synthesis in a time- and magnitude-dependent fashion. Cyclic tensile stretch also enhanced superoxide dismutase (SOD) activity. The disruption of microfilaments with cytochalasin D abolished the stress-induced ROS synthesis. Rotenone, an inhibitor of the mitochondrial electron transport chain, enhanced stress-induced ROS synthesis. These data suggest that actin filament and mitochondria are involved in this action.

Actins↗

Origin of the long common channel based on pancreatographic findings in pancreaticobiliary maljunction.

BACKGROUND AND AIMS: The origin of a long common channel in pancreaticobiliary maljunction was suggested to be the ventral pancreatic duct. Pathogenesis of long common channels was investigated by anatomically analysing the arrangement of pancreatic ducts in pancreaticobiliary maljunction. MATERIALS AND METHODS: Cholangiopancreatography was performed for 66 cases of pancreaticobiliary maljunction and 200 controls. The accessory pancreatic duct was classified according to course and shape. In cases with long- or short-type accessory pancreatic duct, lengths of the main pancreatic duct from orifice to first inferior branch and junction with the accessory pancreatic duct, and the common channel were measured. RESULTS: Lengths of the main pancreatic duct from orifice to first inferior branch or junction with the accessory pancreatic duct were significantly longer in cases of pancreaticobiliary maljunction cases with the long- or short-type accessory pancreatic duct than in controls (p<0.01). Lengths of the main pancreatic duct from first inferior branch to junction with the accessory pancreatic duct were roughly equivalent in pancreaticobiliary maljunction and controls. CONCLUSIONS: Long common channels in pancreaticobiliary maljunction might be formed embryologically with adhesion of the right ventral pancreatic duct and the terminal portion of the bile duct.

Bile Ducts, Extrahepatic↗

[Surgical management of papillary muscle rupture following acute myocardial infarction].

Papillary muscle rupture is a rare but severe complication of acute myocardial infarction. Two cases successfully underwent mitral valve replacement and concomitant coronary artery bypass grafting (CABG) for acute myocardial infarction with the anterior papillary muscle rupture in cardiogenic shock. Each of them needed preoperative massive inotropic infusion, respiratory support and intraaortic balloon pumping assist. The first case was a 76-year-old female. Double vessel disease (seg 7 : 90%, seg 11 : 100%) was revealed by coronary angiography and rupture of the papillary muscle was confirmed by transesophageal echocardiography. The second case was a 69-year-old female. Double vessel disease (seg 2 : 90%, seg 11 : 100%) was revealed and severe mitral regurgitation due to prolapse of the anterior leaflet was confirmed by transthoracic echocardiography. To assess the diagnosis of postinfarction papillary muscle rupture, transthoracic and/or transesophageal echocardiography is mandatory. Coronary angiography is also desirable because concomitant myocardial revascularization may improve the prognosis.

Aged↗

Enhancement of nitric oxide and proteoglycan synthesis due to cyclic tensile strain loaded on chondrocytes attached to fibronectin.

OBJECTIVE: Mechanical stress is an essential factor in the pathogenesis of osteoarthrosis. We sought to determine whether the strain-mediated alteration in proteoglycan (PG) synthesis was modulated by nitric oxide (NO) synthesis. METHODS: Cyclic tensile strain was applied to bovine articular chondrocytes. PG and NO synthesis were determined by [35S] sulfate incorporation and chemiluminescence analysis, respectively. To determine the expression of inducible NO synthase (iNOS), quantitative RT-PCR was used. RESULTS: Enhanced PG and NO synthesis were evident when cyclic tensile strain was applied to chondrocytes seeded on fibronectin-coated plates. When NO production was inhibited, PG synthesis was further enhanced. CONCLUSIONS: Cyclic tensile strain loaded on the chondrocytes enhanced NO synthesis and this enhanced NO inhibited PG synthesis.

Animals↗

Meta-analysis on the validity of pepsinogen test for gastric carcinoma, dysplasia or chronic atrophic gastritis screening.

AIM: To assess the validity of the measurement of pepsinogen I and II as a screening test for gastric cancer and pre-malignant lesions, namely low-grade dysplasia, both in the general population and in selected groups of patients. METHODS: A meta-analysis of sensitivity and specificity results from individual papers on the use of the pepsinogen test. An intrinsic cut-off effect was assumed and a random effect model was used for pooling. RESULTS: Forty-two data sets were included: 27 (64%) population-based screening studies (n=296,553) and 15 (36%) sets of selected individuals (n=4385). Homogenous sensitivity and diagnostic odds ratio (DOR) estimates were found in studies using both pepsinogen I levels and pepsinogen I/II ratio calculations. Pooled pairs of sensitivity and false positive rates (FPr) for pepsinogen I < or = 70; pepsinogen I/II ratio < or = 3, pepsinogen I < or =50; pepsinogen I/II ratio < or = 3, and pepsinogen I < or = 30; pepsinogen I/II ratio < or = 2, were sensitivity 77%/FPr 27%, sensitivity 68%/FPr 31%, and sensitivity 52%/FPr 84%, respectively. Positive predictive values (PPV) varied between 0.77% and 1.25%, and negative predictive values (NPV) varied between 99.08% and 99.90%. In selected groups, pooling was only possible when considering pepsinogen I < or = 70; pepsinogen I/II ratio < or = 3: giving sensitivity 57%, specificity 80%, PPV 15% and NPV 83%. As for the diagnosis of dysplasia, studies considering pepsinogen I <50; pepsinogen I/II ratio <3 obtained sensitivity 65% and specificity ranging from 74%-85%, both with NPV >95%. CONCLUSION: Pepsinogen test definition should include pepsinogen I/II ratio as consistency was obtained, both in population based studies and in selected groups for those studies that used pepsinogen I serum levels together with pepsinogen I/II ratio for screening for gastric cancer in high-incidence regions other than Japan. Further studies of this test in the management of high-risk patients seem to be worthwhile.

False Positive Reactions↗

Effects of insulin on long-term potentiation in hippocampal slices from diabetic rats.

AIMS/HYPOTHESIS: Cognitive deficits occur commonly in diabetic patients. It is unclear whether these impairments result from hypoglycaemia during intensive insulin therapy, or from the diabetes itself. The aim of this study was to examine if impaired energy utilization resulting from insulin deficiency contributes to impaired long-term potentiation (reflecting impaired synaptic plasticity). As long-term potentiation is considered a candidate cellular mechanism underlying learning and memory, understanding how diabetes alters long-term potentiation may provide insight into mechanisms producing cognitive deficits in diabetes. METHODS: Electrophysiologic recordings were used to study long-term potentiation in the CA1 region of hippocampal slices from healthy rats and rats with streptozotocin-induced diabetes. RESULTS: Long-term potentiation was difficult to induce in slices from diabetic rats in standard recording buffer (contains 10 mmol/l glucose). In slices from diabetic rats, increasing extracellular glucose failed to recover long-term potentiation induction, but 10 mmol/l pyruvate added to standard buffer enabled long-term potentiation induction. Moreover, incubation of slices from diabetic rats with insulin enabled long-term potentiation induction in standard buffer. Acute administration of streptozotocin alone did not impair long-term potentiation in slices from healthy animals, and changing extracellular glucose concentrations over the range of 5 mmol/l to 30 mmol/l did not alter long-term potentiation in slices from control rats. CONCLUSIONS/INTERPRETATION: These observations suggest that impaired energy utilization from insulin deficiency, rather than the accompanying hyperglycaemia, impair long-term potentiation in diabetes. Impaired hippocampal synaptic plasticity could contribute to learning and cognitive impairment in diabetic patients.

Animals↗

Cyclic tensile stretch loaded on bovine chondrocytes causes depolymerization of hyaluronan: involvement of reactive oxygen species.

OBJECTIVE: We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. Decreased size of hyaluronan (HA), the major macromolecule in synovial fluid, to which it imparts viscosity, is reported in patients with arthritis. The purpose of this study was to determine the alteration in the molecular weight range of HA as a result of mechanical deformation loaded on the chondrocytes, as well as the involvement of ROS in this action. METHODS: ROS were generated via the oxidation of hypoxanthine by xanthine oxidase. Cyclic tensile stretch was loaded using a vacuum-operated instrument. Levels of HA were measured using a sandwich enzyme-binding assay. Superoxide dismutase (SOD) activity and ROS were measured using water-soluble tetrazolium and a chemiluminescent probe, respectively. RESULTS: ROS depolymerized HA molecules. Cyclic tensile stretch depolymerized HA and induced ROS. SOD inhibited not only ROS induction but also HA depolymerization caused by the mechanical stress. CONCLUSION: ROS play an important role in mechanical stress-induced HA depolymerization.

Animals↗

Synaptic loss following depletion of noradrenaline and/or serotonin in the rat visual cortex: a quantitative electron microscopic study.

Biogenic amines have a trophic-like role for the formation and the maintenance of synapses in the CNS. We examined the changes in the number of synaptic profiles in the developing and adult rat visual cortex following selective depletion of noradrenaline and/or serotonin. By the drug-induced decreases in levels of noradrenaline or serotonin between 1 and 2 weeks after birth, the number of synaptic profiles was decreased by 29-55% compared with that of control animals. The magnitude of reduction in the number of synaptic profiles was virtually the same following simultaneous depletion of both noradrenaline and serotonin compared with the depletion of noradrenaline or serotonin alone. Later in the developmental period, the function of noradrenaline and serotonin in facilitating synapse formation and maintenance became less prominent than that in younger animals. In the control animals, the number of axosomatic synapses was the highest at around 2 weeks after birth, and decreased with development. The number of axodendritic synapses was the highest between 2 and 7 weeks after birth, and decreased to 50% at 11 weeks after birth. These data demonstrate that synapses in the rat visual cortex are overproduced during the early developmental period. We suggest that both serotonin and noradrenaline are necessary for synapse formation during the early stages of development of the rat visual cortex.

Aging↗

Effects of fructose-1,6-bisphosphate on morphological and functional neuronal integrity in rat hippocampal slices during energy deprivation.

D-fructose-1,6-bisphosphate, a high energy glycolytic intermediate, attenuates ischemic damage in a variety of tissues, including brain. To determine whether D-fructose-1,6-bisphosphate serves as an alternate energy substrate in the CNS, rat hippocampal slices were treated with D-fructose-1,6-bisphosphate during glucose deprivation. Unlike pyruvate, an endproduct of glycolysis, 10 mM D-fructose-1,6-bisphosphate did not preserve synaptic transmission or morphological integrity of CA1 pyramidal neurons during glucose deprivation. Moreover, during glucose deprivation, 10-mM D-fructose-1,6-bisphosphate failed to maintain adenosine triphosphate levels in slices. D-fructose-1,6-bisphosphate, however, attenuated acute neuronal degeneration produced by 200 microM iodoacetate, an inhibitor of glycolysis downstream of D-fructose-1,6-bisphosphate. Because (5S, 10R)-(+)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine, an antagonist of N-methyl-D-aspartate receptors, exhibited similar protection against iodoacetate damage, we examined whether (5S, 10R)-(+)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine and D-fructose-1,6-bisphosphate share a common neuroprotective mechanism. Indeed, D-fructose-1,6-bisphosphate diminished N-methyl-D-aspartate receptor-mediated synaptic responses and partially attenuated neuronal degeneration induced by 100-microM N-methyl-D-aspartate. Taken together, these results indicate that D-fructose-1,6-bisphosphate is unlikely to serve as an energy substrate in the hippocampus, and that neuroprotective effects of D-fructose-1,6-bisphosphate are mediated by mechanisms other than anaerobic energy supply.

Adenosine Triphosphate↗

Hydrogen peroxide induces apoptosis of chondrocytes; involvement of calcium ion and extracellular signal-regulated protein kinase.

OBJECTIVE: Recent observations demonstrated that reactive oxygen species facilitate cartilage degradation. We demonstrated that hydrogen peroxide (H2O2) caused inhibition of proteoglycan synthesis, induction of apoptosis and stimulation of extracellular signal-regulated protein kinase (ERK) of the chondrocytes (Inflamm Res 48: 399-403, 1999). To determine whether activation of ERK is involved in the induction of chondrocyte apoptosis, we examined the signal transduction pathways in this hydrogen peroxide induced apoptosis. DESIGN: Bovine articular chondrocytes were cultured. To determine the induction of apoptosis, Annexin V staining and terminal deoxynucleotidyl transferase were used. The activity of caspase-3 was measured using an apopain assay kit. Intracellular Ca2+ imaging was observed after fura2-AM loading. RESULTS: Hydrogen peroxide enhanced annexin V positive apoptotic cells and caspase-3 activity, which is an executor of apoptosis. Hydrogen peroxide also enhanced intracellular Ca2+ and preincubation with the intracellular Ca2+ chelator protected chondrocytes against hydrogen peroxide-induced cell apoptosis, indicating that an increase in the cytosolic Ca2+ plays a decisive role in this action. When ERK activity was blocked with geldanamycin and PD098059, increased apoptosis was evident. CONCLUSION: Hydrogen peroxide induces chondrocyte apoptosis via Ca2+ signaling, and ERK is involved in these signal transduction pathways.

Animals↗

Preliminary study of fortnightly irinotecan hydrochloride plus cisplatin therapy in patients with advanced gastric and colorectal cancer.

PURPOSE: Irinotecan hydrochloride shows a strong activity against gastric cancer and colorectal cancer, while combined therapy with irinotecan and cisplatin is useful for gastric cancer. However, myelosuppression and diarrhea are still dose-limiting factors. To reduce such toxicities to enable therapy to be performed on an outpatient basis, we tested the effect of divided administration of cisplatin. METHODS: Irinotecan (60 mg/m2) plus cisplatin (30 mg/m2) were administered on days 1 and 15 every 4 weeks to 13 patients with advanced gastric cancer and 13 with advanced colorectal cancer. Treatment was continued if a leukocyte count > or = 3000/mm3, a platelet count > or = 100,000/mm3, and grade 0 diarrhea were confirmed. Doses were reduced if grade 3-4 hematological toxicity and grade 2 or higher nonhematological toxicity occurred. RESULTS: The major toxicity was leukopenia (neutropenia), but grade 3-4 nonhematological toxicity was not observed. The response rate was 41.7% for gastric cancer (5/12 evaluable patients) and 36.7% for colorectal cancer (4/11 evaluable patients). The median survival time was 313 days (range 29-920 days) for gastric cancer patients and 490 days (range 83-1184 + days) for colorectal cancer patients. CONCLUSION: Fortnightly administration of irinotecan and cisplatin (with a divided cisplatin dose) seems to be a useful regimen for gastrointestinal cancer. It reduces toxicity while maintaining a good antitumor effect.

Adult↗

Endoscopic therapy with absolute ethanol for postoperative recurrent ulcers in intestinal Behçet's disease, and simple ulcers.

BACKGROUND: When examined macroscopically and histologically, there are no differences between "simple" intestinal ulcers and intestinal ulcers of Behçet's disease. The postoperative recurrence of intestinal Behçet's disease and simple ulcers was frequently. Medical treatment for postoperative recurrent ulcers is palliative, and the patient often requires surgery. We studied about an effect of absolute ethanol spraying via endoscopy for the ulcers. METHOD: The postoperative rate of recurrence was 56% (9/16). Commonly the ulcer recurred around the anastomotic region. We performed spraying for recurrent ulcers with absolute ethanol via endoscope in four patients. RESULTS: This therapy was effective for the recurrent ulcer in the 4 patients. In this study, the patients who were monitored and treated by the spraying of ethanol did not require further surgery. CONCLUSIONS: This therapy should performed for recurrent ulceration in cases of simple ulcer and intestinal Behçet's disease.

Administration, Topical↗

Efficacy of a 14-day course of oral ciprofloxacin therapy for acute uncomplicated pyelonephritis.

This study aimed to evaluate the efficacy and safety of oral antibacterial treatment with fluoroquinilone for acute uncomplicated pyelonephritis Thirteen female patients with acute uncomplicated pyelonephritis were treated with oral fluoroquinilone (ciprofloxacin; CPFX). They received 200 mg of the drug three times a day while febrile (3-5 days). Once they become afebrile, the same dose of the drug, given twice a day, was given for another 9-11 days. The mean duration of the course of CPFX was 14 days. Symptoms were evaluated, and laboratory examinations, including urine culture and measurement of the minimal inhibitory concentration (MIC) of CPFX were conducted before treatment, and 3, 7, 14, 21, and/or 28 days after the initiation of the treatment. Of the 13 patients, only 5 needed to be hospitalized, and the period of hospitalization was only a few days. On the 14th day after the commencement of treatment, bacteriologic and clinical cure rates were 100%. Escherichia coli was the most common uropathogen, being isolated from the urine of 8 patients. No clinical relapse of the disease was found during a follow-up period of up to 4 weeks. The patients tolerated the drug well without developing any serious adverse effects. Oral antimicrobial chemotherapy with fluoroquinolone, given on an outpatient or short-term hospitalization basis, achieved satisfactory bacteriological and clinical outcomes in the treatment of acute uncomplicated pyelonephritis. This treatment regimen is indicated for patients with this disease who are not in a serious condition with complications such as shock.

Acute Disease↗

Cyclic tensile stretch inhibition of nitric oxide release from osteoblast-like cells is both G protein and actin-dependent.

Recent reports indicate the alteration of nitric oxide (NO) synthesis with mechanical stress loaded on the osteoblast and NO is considered to have a significant role in mechanotransduction. We found the involvement of guanine-nucleotide-binding regulatory proteins (G proteins), especially Gi, in stress-inhibited NO release of osteoblast-like cells (JOR:17;593-597, 1999). To determine further the mechanism involved in this process, we measured c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) activity under cyclic tensile stretch loaded on osteoblast-like cells. Cyclic stretch significantly enhanced JNK/SAPK activity and pertussis toxin clearly reversed stress-enhanced JNK/SAPK activity. Cytochalasin D, actin microfilament disrupting reagent, also abolished the stress activation of JNK/SAPK. We propose a model for signaling events induced by cyclic tensile stretch, namely a transmembrane mechanosensor which couples Gi-protein, actin cytoskeleton and finally activates JNK/SAPK activity of osteoblasts.

Actins↗

Staphylococcus aureus bacteriuria and surgical site infections by methicillin-resistant Staphylococcus aureus.

Surgical site infection (SSI) remains an important cause of morbidity among hospitalized patients. We reviewed 421 patients who underwent open urological operations between January 1993 and December 1997 in our institute. Group I consisted of 259 patients who received uncontrolled antimicrobial prophylaxis (AMP) between 1993 and 1995. Group II consisted of 162 patients who received controlled AMP between 1996 and 1997. In group II, penicillins or first to second-generation cephalosporins was used and the duration of use for these agents regulated according to the wound class of each operation. The operations with clean wounds showed the lowest rate of SSI in both groups; the operations with contaminated wounds showed the highest rate of SSI (32.0% in group I and 33.3% in group II). There was no significant difference in the total rates of SSI between the two groups (P=0.216). The most frequently isolated bacterial species was methicillin-resistant Staphylococcus aureus (MRSA), isolated in 73.3% of the cases in group I and in 93.3% in group II. There was no significant difference in the incidence of MRSA isolation between the two groups (P=0.114). The controlled AMP could not lower the incidence of MRSA-induced SSIs. In SSI patients, 22.7% of group I and 35.7% in group II, had MRSA bacteriuria before operation. The prohibition of third-generation cephalosporins and shorter duration of AMP did not reduce the incidence of SSI induced by MRSA because MRSA was not the emerging microorganism but rather a resident in the urological ward. On the other hand, the total incidence of SSI did not increase after regulation of AMP. This finding suggests that older antibacterial agents can prevent infection, except those caused by resistant microorganisms such as MRSA. The effective counter-measure for the prevention of MRSA-induced SSI is needed.

Anti-Infective Agents, Urinary↗