Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 163 records · Page 9Linked to original sources

PubMed1998

Clinical application of power Doppler imaging to visualize coronary arteries in human beings.

Supplementation of angiographic information during bypass procedures is an attractive goal for the echocardiographic researcher. Compared with color flow mapping, power Doppler imaging is superior in terms of identifying small vessels and noise suppression because of the use of Doppler signal strength for imaging. Although power Doppler imaging does not provide information about flow velocity or its direction, it does show detailed vessel flow in a static organ. Our study was designed to obtain angiographic images of the coronary artery by the use of power Doppler imaging in 31 patients during open heart surgery. During cold cardioplegic infusion, the epicardial coronary artery and the coronary artery within myocardium, such as the septal perforator, could be well visualized by power Doppler imaging. There was good correlation between the diameters of coronary arteries measured from power Doppler imaging and those from quantitative coronary angiography (r = 0.964, p < 0.0001). We obtained clear and accurate images of the coronary artery by using power Doppler imaging during cardiac standstill. These images might provide meaningful supplemental information to the operator, such as confirming the target coronary artery during the cardioplegia and choosing the appropriate arterial portion for a bypass operation.

Cardiac Surgical Procedures↗

PubMed1998

Left ventricular geometry as an independent predictor for extracardiac target organ damage in essential hypertension.

Left ventricular hypertrophy (LVH) is an independent cardiovascular risk factor. It has not been established, however, whether left ventricular geometry is an independent predictor of extracardiac target organ damage in essential hypertension. Study groups were classified according to relative wall thickness: 27 patients with concentric LVH and 50 patients with eccentric LVH. Age and left ventricular mass indexes of two groups were matched. As indexes of extracardiac target organ damage, retinal funduscopic grade, and serum creatinine level were measured. The severity of hypertensive retinopathy and the renal involvement were more severe in patients with concentric LVH than in patients with eccentric LVH. Extracardiac target organ damage was consistently higher in patients with concentric LVH than in those with eccentric LVH. Systemic hemodynamics paralleled ventricular geometric patterns, with higher peripheral resistance and lower aortic compliance in patients with concentric LVH, whereas end-diastolic volumes and stroke volumes were higher in patients with eccentric LVH than in patients with concentric LVH. In addition, total peripheral resistance was related to retinal fundoscopic grade (r = 0.41, P < .01), and serum creatinine level (r = 0.28, P < .05). Even in the presence of an identical degree of LVH, echocardiographically determined left ventricular geometry may provide a further independent stratification of extracardiac target organ damage in essential hypertension.

Aged↗

PubMed1998

Hemostatic activation and cardiac events after the 1995 Hanshin-Awaji earthquake.

Earthquake-induced stress seems to induce rheological deterioration associated with high blood pressure, an increase of blood viscosity due to hemoconcentration and an increase of the fibrinogen level. These changes lead to prolonged endothelial cell injury and accelerate fibrin turnover as the result of a high D-dimer level. An increase of these acute changes caused by mental and physical stress after an earthquake might trigger obstructive thrombus in coronary arteries in the elderly.

Disasters↗

PubMed1998

Changes in body temperature following deflation of limb pneumatic tourniquet.

STUDY OBJECTIVES: To investigate changes in both core and peripheral skin-surface temperatures during and after application of a unilateral leg pneumatic tourniquet in adult patients. DESIGN: Prospective, observational clinical study. SETTING: University hospital. PATIENTS: 21 ASA physical status I and II adult patients scheduled for elective leg orthopedic surgery with lumbar epidural anesthesia. INTERVENTIONS: Rectal and fingertip skin-surface temperatures were recorded every minute after steady-state lumbar epidural anesthesia was established. MEASUREMENTS AND MAIN RESULTS: Significant (p < 0.05) increases in both rectal and fingertip temperatures were observed during tourniquet application for 91 +/- 6 minutes from 36.5 +/- 0.14 degrees C to 37.0 +/- 0.17 degrees C and from 32.6 +/- 0.79 degrees C to 35.5 +/- 0.44 degrees C, respectively. In contrast, both rectal and fingertip temperatures progressively decreased following tourniquet release; significant (p < 0.05) decreases in the rectal and fingertip temperatures were observed 6 and 5 minutes after tourniquet release, respectively. Decreases (approximately maximum) in the rectal and fingertip temperatures 15 minutes after tourniquet release were 0.25 +/- 0.05 degrees C and 1.26 +/- 0.26 degrees C, respectively. In each case, changes in fingertip temperature were approximately six times greater than those in the rectal temperature. CONCLUSIONS: Limb tourniquets appear to cause thermal perturbations during epidural anesthesia. The progressive increases in core temperature during tourniquet application presumably resulted from constraint of metabolic heat to the core thermal compartment, and the greater increases in the skin-surface temperature during tourniquet application appear to represent vasodilation in response to the core hyperthermia. On the other hand, redistribution of body heat and the efflux of hypothermic venous blood from the tourniqueted area into systemic circulation following tourniquet deflation probably decreased the core temperature, which might switch off the thermoregulatory vasodilation, leading to the decreases in skin-surface temperature. Recognition of these thermal perturbations are useful in diagnosing intraoperative thermal perturbations.

Adult↗

PubMed1998

Massive retroperitoneal hemorrhage associated with femoral vein cannulation.

The right external iliac artery was inadvertently punctured during attempted right femoral vein catheterization. Severe hypotension developed several minutes after the arterial puncture. Concurrently, a large right lower abdominal quadrant swelling (approximately 5 cm in diameter) became apparent. Laparoscopic observation of the retroperitoneal region immediately revealed massive retroperitoneal hemorrhage. Abdominal computerized tomographic scan indicated development of a huge (approximately 10 cm in the maximum diameter) retroperitoneal hematoma along the right psoas muscle from the level of the right external iliac vessels up to the level of the upper pole of the right kidney. Consideration of the anatomy of the "right" femoral and retroperitoneal vessels (ie, mediolateral relationship between the vein and artery) led us to conclude that the site for insertion of the needle was too proximal and the angle for advancement of the needle too low in our patient, allowing the needle to reach and injure the "incompressible" external iliac artery, thereby causing massive retroperitoneal hemorrhage. Although femoral vein catheterization has generally been considered a relatively safe method of intravenous access, a life-threatening serious complication can occur with the inappropriate technique used in our case.

Catheterization, Peripheral↗

PubMed1998

Activation of non-primary motor areas during a complex finger movement task revealed by functional magnetic resonance imaging.

We examined the brain activation induced by a complex finger movement task using functional magnetic resonance imaging (fMRI) with echo planar imaging (EPI). Imaging planes were set up for the observation of non-primary motor areas. Among five normal males examined, four subjects naive to the task showed activations in contralateral primary and supplementary motor areas and the ipsilateral superior anterior part of the cerebellar hemisphere. Also, the bilateral premotor areas and the contralateral ventrolateral nucleus of thalamus were occasionally activated. No changes were observed in the putamen and globus pallidus. The subject accustomed to the task showed activation in the narrow areas of the contralateral primary motor and supplementary motor and premotor areas but not in the cerebellum. These results suggest that fMRI has nearly the same degree of detectability to that of positron emission tomography (PET) in regard to motor functions.

Adult↗

PubMed1998

Depressive disorders as psychiatric complications after obesity surgery.

Three case reports of morbidly obese patients (two women and a man) who underwent vertical banded gastroplasty and who subsequently fell into depression, are presented here. The psychiatric diagnosis according to DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised), the eating pattern before obesity surgery, the past history of mental disorder, social adaptation before surgery, psychological gain from their obese state, and the presence of unrealistic expectations of obesity surgery were investigated. Case 1 was diagnosed postoperatively as having a major depressive episode without a personality disorder. Case 2 was diagnosed post-operatively as having a major depressive episode. Case 3 had a depressive disorder not otherwise specified. Cases 2 and 3 had a social phobia with comorbidity of personality disorders. Binge eating disorder was confirmed in all patients before obesity surgery. There were differences between case 1 and cases 2 and 3 based on the presence of personality disorder and the time of onset of depression. When some psychiatric characteristics are confirmed in obese patients, obesity surgery should be undertaken more prudently because the patients may manifest depression postoperatively. The pre-operative psychiatric assessment is essential for a decision on indication of obesity surgery.

Adult↗

PubMed1998

Successful treatment with nedaplatin in patients with ovarian cancer that recurred after platinum-containing chemotherapy: report of two cases.

We report the successful treatment with nedaplatin of two cases of ovarian cancer that recurred after platinum-containing chemotherapy. A 52-year-old woman presented in June 1994 with massive accumulation of ascitic fluid. Pathological diagnosis of the specimen obtained at surgery in July 1994 was serous papillary adenocarcinoma of the ovary. In September 1995, approximately seven months after the completion of six cycles of CAP chemotherapy (cyclophosphamide, adriamycin and cisplatinum), she was referred to our hospital because of massive accumulation of ascitic fluid. The carbohydrate antigen 125 (CA-125) value was 485 U/ml. Cytologic study of her ascitic fluid was positive for adenocarcinoma cells. She did not respond to intravenous irinotecan and two cycles of intraperitoneal cisplatin. Nedaplatin 100 mg/m2 was administered. Complete response was achieved in September 1996 and continued for four months with a total of seven cycles of nedaplatin. The second case was a 60-year-old woman who was admitted to our hospital in December 1994 because of ascitic fluid. Diagnosis of ovarian cancer was based on an elevated level of CA-125 (1380 U/ml). Treatment with CAP and CC (cyclophosphamide and carboplatin) maintained a partial response for seven months. In August 1996, her disease progressed, although she was receiving CC therapy. Nedaplatin 100 mg/m2 was administered. Partial response was achieved again in November 1996 and continued for four months, with a total of five cycles of nedaplatin. In the light of our experience, treatment with nedaplatin in a patient with recurrent ovarian cancer might be worthwhile as palliative chemotherapy.

Adenocarcinoma, Papillary↗

PubMed1998

Geographic clustering patterns in mortality from biliary tract cancer in Japan.

We calculated the standardized mortality ratios (SMRs) of biliary tract cancer (BTC) in Japan from 1981 to 1990 and statistically analyzed the results according to 333 Secondary Areas of Medical Care, as well as sex and subsite [gallbladder cancer (GBC) and extrahepatic bile duct cancer (BDC)], in order to examine geographic clustering patterns of BTC. In GBC in both sexes, the Secondary Areas of Medical Care with high SMRs were clustered in the eastern part of Japan. In BDC in both sexes, the Areas with high SMRs were clustered between the northern and eastern parts of Japan. In comparison with GBC, this clustering favored the northern part of Japan. In males, the clustering pattern in mortality from BTC was mainly due to the occurrence of BDC. In females, the clustering pattern in mortality from BTC reflected that of GBC. The clustering of BTC, especially GBC, seems to be related to the distribution of plains, basins, and rivers.

Adolescent↗

PubMed1998

In vitro cytotoxic effects of vacuolating cytotoxin produced by clinical isolates of Helicobacter pylori.

The vacuolating cytotoxin produced by Helicobacter pylori is considered to be one virulence factor causing peptic ulceration. In this study, we examined the activity of vacuolating cytotoxin in induction of intracellular vacuolation of rabbit gastric epithelial cells (RGECs). We used culture supernatants of H. pylori as a source of vacuolating cytotoxin and quantitated cytotoxic activity by the MTT method. Intracellular vacuolation of RGECs was observed in the presence of 36 of 57 (63%) clinically isolated H. pylori strains. However, there were no differences in the incidence of H. pylori strains with positive vacuolating cytotoxin (Tox+) among patients with gastritis, gastric ulcers or duodenal ulcers. The MTT assay showed that the cytotoxic activity of H. pylori supernatants obtained from patients with gastric ulcers was significantly higher than in patients with gastritis (p < 0.01), but was not different to duodenal ulcer patient supernatants. Similar results were also observed in Tox+ isolates, however, there were no significant differences between patients with regard to the incidence of vacuolating cytotoxin-negative isolates. Although our data may not indicate a clear correlation between prevalence of vacuolating cytotoxin and clinical manifestations, they suggest that H. pylori harboring vacuolating cytotoxin may particularly induce damage to the gastric epithelium in patients with gastric ulcers.

Animals↗

PubMed1998

[Acute respiratory distress syndrome complicating imported Plasmodium falciparum malaria].

A 25-year-old male, who had returned from the Republic of Mali in Africa, was admitted to our hospital because of a 3-day history of high fever, on the first of October 1996. He was diagnosed as Plasmodium falciparum malaria by peripheral blood smear. From the admission day he was treated with quinine HCL, 1,500 mg per day, and sulfamethoxazole 2,400 mg trimethoprim 480 mg per day, but on October 2nd blood examination showed 35% parasite density and he was given mefloquine. However he was complicated with DIC on October 3rd, ARDS on October 5th. By anti-coagulant therapy and methylprednisolone pulse therapy he became afebrile and respiratory function improved rapidly. ARDS should be emphasized as a severe complication of imported severe malaria.

Adult↗

PubMed1998

NorM, a putative multidrug efflux protein, of Vibrio parahaemolyticus and its homolog in Escherichia coli.

We found that cells of Vibrio parahaemolyticus possess an energy-dependent efflux system for norfloxacin. We cloned a gene for a putative norfloxacin efflux protein from the chromosomal DNA of V. parahaemolyticus by using an Escherichia coli mutant lacking the major multidrug efflux system AcrAB as the host and sequenced the gene (norM). Cells of E. coli transformed with a plasmid carrying the norM gene showed elevated energy-dependent efflux of norfloxacin. The transformants showed elevated resistance not only to norfloxacin and ciprofloxacin but also to the structurally unrelated compounds ethidium, kanamycin, and streptomycin. These results suggest that this is a multidrug efflux system. The hydropathy pattern of the deduced amino acid sequence of NorM suggested the presence of 12 transmembrane domains. The deduced primary structure of NorM showed 57% identity and 88% similarity with that of a hypothetical E. coli membrane protein, YdhE. No reported drug efflux protein in the sequence databases showed significant sequence similarity with NorM. Thus, NorM seems to be a novel type of multidrug efflux protein. We cloned the ydhE gene from E. coli. Cells of E. coli transformed with the cloned ydhE gene showed elevated resistance to norfloxacin, ciprofloxacin, acriflavine, and tetraphenylphosphonium ion, but not to ethidium, when MICs were measured. Thus, it seems that NorM and YdhE differ somehow in substrate specificity.

Amino Acid Sequence↗

PubMed1998

A putative multisubunit Na+/H+ antiporter from Staphylococcus aureus.

We cloned several genes encoding an Na+/H+ antiporter of Staphylococcus aureus from chromosomal DNA by using an Escherichia coli mutant, lacking all of the major Na+/H+ antiporters, as the host. E. coli cells harboring plasmids for the cloned genes were able to grow in medium containing 0.2 M NaCl (or 10 mM LiCl). Host cells without the plasmids were unable to grow under the same conditions. Na+/H+ antiport activity was detected in membrane vesicles prepared from transformants. We determined the nucleotide sequence of the cloned 7-kbp region. We found that seven open reading frames (ORFs) were necessary for antiporter function. A promoter-like sequence was found in the upstream region from the first ORF. One inverted repeat followed by a T-cluster, which may function as a terminator, was found in the downstream region from the seventh ORF. Neither terminator-like nor promoter-like sequences were found between the ORFs. Thus, it seems that the seven ORFs comprise an operon and that the Na+/H+ antiporter consists of seven kinds of subunits, suggesting that this is a novel type of multisubunit Na+/H+ antiporter. Hydropathy analysis of the deduced amino acid sequences of the seven ORFs suggested that all of the proteins are hydrophobic. As a result of a homology search, we found that components of the respiratory chain showed sequence similarity with putative subunits of the Na+/H+ antiporter. We observed a large Na+ extrusion activity, driven by respiration in E. coli cells harboring the plasmid carrying the genes. The Na+ extrusion was sensitive to an H+ conductor, supporting the idea that the system is not a respiratory Na+ pump but an Na+/H+ antiporter. Introduction of the plasmid into E. coli mutant cells, which were unable to grow under alkaline conditions, enabled the cells to grow under such conditions.

Amino Acid Sequence↗

PubMed1998

Beneficial hemodynamic effects of oral prostacyclin (PGI2) analogue, beraprost sodium, on a patient with primary pulmonary hypertension--a case report.

A 65-year-old woman was admitted to our hospital because of exertional dyspnea in 1987. A diagnosis of primary pulmonary hypertension was confirmed by right heart catheterization. She had received conventional therapy in the outpatient clinic. She was readmitted with the deterioration of exertional dyspnea in 1995. Stabilization of pulmonary hemodynamics, while not achieved with conventional therapy, was achieved with additive administration of an oral prostacyclin (PGI2) analogue, beraprost sodium.

Administration, Oral↗

PubMed1998

Coronary vasospasm at the site of myocardial bridge--report of two cases.

Two patients with angina pectoris and postmyocardial infarction angina due to coronary vasospasm at the site of myocardial bridge are described. Intracoronary injection of isosorbide dinitrate led to resolution of coronary vasospasm on acetylcholine provocation test, and vasospastic angina pectoris has been well controlled after treatment with calcium channel blockers.

Angina Pectoris↗

PubMed1998

Clinical characteristics in Japanese patients with coexistent hypertrophic cardiomyopathy and coronary vasospasm.

There are only a few reports concerning coexistent hypertrophic cardiomyopathy (HCM) and vasospastic angina. Clinical characteristics in patients with both diseases have not been clarified yet. This study was designed to elucidate the relationship between chest pain and coronary vasospasm in HCM patients and to delineate clinical characteristics in patients with both HCM and coronary vasospasm. First, 36 patients with HCM underwent acetylcholine provocation test for coronary vasospasm and were divided into two groups on the basis of presence or absence of coronary vasospasm. Next, the following risk factors for coronary artery disease were compared between the two groups: hypertension, smoking, hyperlipidemia, diabetes mellitus, and hyperuricemia. Coronary vasospasm was induced in 10 (28%) of 36 patients with HCM. There were no significant differences in age and male gender between the two groups. Smoking was more prominent in HCM patients with than without coronary vasospasm (80% vs 35%, p<0.05), but there were no differences in the prevalence of other risk factors between the two groups. In conclusion, coronary vasospasm appears to play a significant role in the etiology of myocardial ischemia in Japanese patients with HCM, and smoking might be a major risk factor for coexistence of HCM and coronary vasospasm.

Adult↗

PubMed1998

Preparation and characterization of everted membrane vesicles from cells of Staphylococcus aureus.

We developed a method for the preparation of everted membrane vesicles from cells of Staphylococcus aureus. The cells were first treated with ampicillin to weaken the peptidoglycan layer, then the cells were passed through a French press cell. The resulting vesicles were roughly 0.1 microm in diameter, judging from electron microscopic observations. We detected fairly high membrane-bound ATPase activity in the membrane vesicles. We observed respiratory-driven quenching of quinacrine fluorescence, which indicates that inward H+ transport took place. These results indicate that the vesicles are everted. We characterized the membrane-bound ATPase. We also detected Na+/H+ antiport, erythromycin/H+ antiport and chloramphenicol/H+ antiport activities in the membranes of S. aureus.

Adenosine Triphosphatases↗

PubMed1998

An early systolic sound associated with midventricular obstruction in a patient with hypertrophic cardiomyopathy.

A 57-year-old woman was admitted for examination because of chest discomfort. Transthoracic echocardiography was performed and she was diagnosed as having hypertrophic cardiomyopathy. An echocardiogram also revealed that she had midventricular obstruction with a pressure gradient of 125 mmHg determined by Doppler echocardiography. A phonocardiogram showed an early systolic sound and the beginning of the sound coincided with the time of septal-posterior wall contact. In addition, the timing also corresponded to the sudden obstruction of blood flow in the region of the midventricular narrowing. Furthermore, this sound markedly decreased with the reduction in pressure gradient caused by cibenzoline treatment. Thus, it was concluded that the early systolic sound was associated with midventricular obstruction and produced by a rapid deceleration of the interventricular flow caused by midventricular obstruction.

Anti-Arrhythmia Agents↗