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Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 91 records · Page 5Linked to original sources
PubMed2000

Preservation of the right atrial appendage improves reduced plasma atrial natriuretic peptide levels after the maze procedure.

OBJECTIVES: The present study was conducted to determine whether preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and whether the increase of plasma atrial natriuretic peptides improves the ability of the kidneys to excrete the fluid load after the operation. METHODS: We evaluated 42 patients who underwent the maze procedure. The right atrial appendage was preserved in 22 patients but not in 20. Blood samples were obtained before and after the operation for measurement of atrial natriuretic peptides. To evaluate the influence of atrial natriuretic peptides on the ability of the kidneys, we also measured body weight, fluid balance, and the doses of furosemide and dopamine administered after the operation. RESULTS: The restoration to sinus rhythm at 1 month after was comparable in the two groups. Plasma atrial natriuretic peptide levels significantly increased after the operation in patients in whom the right atrial appendage was preserved (1 day after: 23.4 +/- 17.8 vs 3 days after: 42.7 +/- 23.6 and 7 days after: 36.3 +/- 23.7 pg/mL, P <.05) but not in patients in whom the right atrial appendage was not preserved (1 day after: 20.0 +/- 19.6, 3 days after: 28.5 +/- 19.3, and 7 days after: 23.0 +/- 16.1 pg/mL). Furthermore, plasma atrial natriuretic peptide levels were significantly lower in patients in whom the right atrial appendage was not preserved than in patients in whom the right atrial appendage was preserved at 3 and 7 days after the operation. The fluid balance during the first 7 days of the postoperative period was comparable in the two groups, although the total dose of dopamine used in the same period was significantly smaller in patients in whom the right atrial appendage was preserved than in patients in whom the right atrial appendage was not preserved (155.3 +/- 119.0 vs 244.9 +/- 129.0 microg/kg, P <.05). CONCLUSIONS: The present study showed that preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and that increased plasma atrial natriuretic peptides may improve the ability of the kidneys to excrete the fluid load after the operation.

Atrial Appendage↗
PubMed2000

Acidification severely suppresses spawning of hime salmon (land-locked sockeye salmon, Oncorhynchus nerka).

A laboratory study was conducted to investigate the effects of an acidic environment on the female sexual behavior of hime salmon (land-locked sockeye salmon, Oncorhynchus nerka). Spawning hime salmon were extremely sensitive to the acidity of ambient water. Nest-digging behavior was severely inhibited (P<0.05) by very slight acidification (pH below 6.4) of the water. Below pH 6.0, females showed almost no diggings. When the ambient water was returned to nearly neutral (pH 6.6), diggings reappeared in four of the six fish tested, whereas in two individuals, none was observed. Avoidance of slightly acidic water in selection of spawning site or cessation of spawning behavior in weakly acidic environments may be the most potent cause of the reduction of salmonid populations in the early stages of acidification.

Animals↗
PubMed2000

Delapril versus manidipine in hypertensive therapy to halt the type-2-diabetes-mellitus-associated nephropathy.

Thirty-nine hypertensive patients with type 2 diabetes mellitus were followed under long-term treatment (mean, 20.7 months) with manidipine hydrochloride, a Ca antagonist, or delapril hydrochloride, an ACE inhibitor, at nine institutions. Both the treatments showed similar antihypertensive effects, although slight but significantly larger decreases were observed in systolic and mean blood pressures at months 12 and 24 in the patients treated with manidipine (P < 0.02). The urinary albumin excretion index (AEI) tended to increase throughout the study in both treatment groups, but no significant difference in AEI was observed between the two treatment groups at any time point. Overt albuminuria developed in four patients on manidipine but did not appear in any of the patients on delapril. The risk of progression to overt albuminuria was significantly different between manidipine and delapril groups (P = 0.011). No increase in serum creatinine (Cr) was observed with delapril. The average excretion indexes of tubular markers such as beta2-microglobulin, alpha1-microglobulin, and NAG tended to be higher in the patients on manidipine than in those on delapril. Taken in sum, these findings suggest that the ACE inhibitor delapril is more beneficial than the Ca antagonist manidipine in the treatment of diabetic renal diseases via mechanisms other than the blood pressure regulation, partly through their different effects on tubular function. In conclusion, delapril was significantly more effective than manidipine in inhibiting progression to overt albuminuria in hypertensive type 2 diabetes mellitus patients.

Adult↗
PubMed2000

Cynomolgus monkey liver aldehyde oxidase: extremely high oxidase activity and an attempt at purification.

Aldehyde oxidase (EC 1.2.3.1) in monkey (Macaca fascicularis) liver was characterized. Liver cytosol exhibited extremely high benzaldehyde and phthalazine oxidase activities based on aldehyde oxidase, compared with those of rabbits, rats, mice and guinea pigs. Monkey liver aldehyde oxidase showed broad substrate specificity distinct from that of the enzyme from other mammals. Purified aldehyde oxidase from monkey liver cytosol showed two major bands and two minor bands in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These bands were also observed in Western blotting analysis using anti-rat aldehyde oxidase. The molecular mass of the enzyme was estimated to be 130-151 kDa by SDS-PAGE, and to be about 285 kDa by HPLC gel filtration. The results suggest that isoforms of aldehyde oxidase exist in monkey livers.

Aldehyde Oxidase↗
PubMed2000

Whole-body metabolism of the organophosphorus pesticide, fenthion, in goldfish, Carassius auratus.

The in vivo metabolism of fenthion, an organophosphorus pesticide, and its sulfoxide (fenthion sulfoxide) was examined in goldfish (Carassius auratus). When goldfish were administered fenthion i.p. at a dose of 100 mg/kg, two metabolites were isolated from the tank water. They were identified as fenthion sulfoxide and fenthion oxon, in which > P = S of fenthion is transformed to > P = O, by comparing their mass and UV spectra, and their behavior in HPLC and TLC, with those of authentic standards. However, fenthion sulfone was not detected as a metabolite. The amounts of fenthion, fenthion sulfoxide and fenthion oxon excreted within 4 days were 2.7, 3.4 and 2.5%, of the initial dose of fenthion, respectively. Unchanged fenthion was detected in the body of the fish to the extent of 42-50% of the dose after 10 days, but fenthion sulfoxide and fenthion oxon showed very low concentrations. When fenthion sulfoxide was administered to the fish, about 70% of the dose was excreted unchanged into the tank water within 24 h, but little of the reduced compound, fenthion, was found. In contrast, fenthion was detected at 2.1% of dose in the body of goldfish as a metabolite of fenthion sulfoxide. The fact that fenthion is metabolized to the toxic oxon form in fish presumably has environmental and health implication for its use as a pesticide.

Animals↗
PubMed2000

Three-channeled aortic dissection in Marfan syndrome.

Among the various types of aortic dissection, three-channeled aortic dissection, in which two adjacent false lumens are present, is rarely observed. The authors surgically treated 20 Marfan syndrome patients with this type of dissection, who accounted for 29.4% of 68 patients with aortic dissection in Marfan syndrome and who were surgically treated in the authors' institution prior to July 1999. Patient age ranged from 24 to 51 years (mean of 40 years). The male:female ratio was 13:7. Valved conduit procedure had been performed previously in 14 patients. Pain was observed at various times in 13 patients. Computed tomography scanning and magnetic resonance imaging were useful for preoperative diagnosis. The morphology of the first and second false lumens was Stanford type A + type B in 10 patients and type B + type B in 10 patients. Re-entry of the second false lumen was observed in five patients. The descending aorta was replaced in 13 patients, thoracoabdominal aortic replacement was performed in five, extra-anatomic bypass in one patient and iliac artery-superior mesenteric artery bypass in one. Four patients died in hospital. There were three late deaths during a follow-up of 1-208 months (mean of 51 months). When pain recurs in Marfan patients with aortic dissection, three-channeled dissection should be suspected and subsequent surgery is required. The incidence of this dissection is high in patients with Marfan syndrome.

Adult↗
PubMed2000

Result of surgical treatments in patients with coronary-arterial obstructive disease after Kawasaki disease.

OBJECTIVE: To determine the efficacy of coronary artery bypass grafting (CABG) in young patients with coronary-arterial obstructive disease subsequent to Kawasaki disease. METHODS: CABG was employed in 100 patients. Age at operation ranged from 1 to 23 years at a mean of 10+/-5 years. The number of bypass grafts placed was 1-5/patient (a mean of 1.7+/-0.8). The left internal-thoracic artery (ITA) was used as a graft in 99 patients; the right internal thoracic artery in 39, the gastroepiploic artery in nine and the saphenous vein in 21. RESULTS: All patients survived the procedures. In the follow-up of 6.7+/-4.5 years, two patients died, one because of a traffic accident and the other due to sudden death. Considerable myocardial ischemia recurred postoperatively in 15, because of either obstruction of the bypass grafts or progression of other coronary-arterial obstructions. Of these, symptoms spontaneously regressed without interventional procedures in four, reoperation was indicated in four and catheter intervention was efficiently carried out in the remaining seven. Another two patients had episodes of critical ventricular arrhythmia; one of them with severe left ventricular dysfunction subsequently underwent cardiac transplantation. The patency rates of the arterial grafts were 94, 82 and 78% at 1, 5 and 10 years, respectively, and this was higher than that of the venous grafts (82, 63 and 36%, respectively). Strenuous exercise is currently prohibited in 15 patients, while the remaining 83 patients are doing well with no obvious restriction in their daily lives. CONCLUSION: Collaborating with catheter interventions, CABG using the arterial grafts can provide attractive results in patients with obstructive coronary arteries associated with Kawasaki disease.

Adolescent↗
PubMed2000

Total cavopulmonary connection in children with body weight less than 10 kg.

OBJECTIVE: To evaluate the results after total cavopulmonary connection (TCPC) in small children, our clinical experience was retrospectively reviewed. METHODS: Of 164 patients undergoing TCPC, the body weight at operation was less than 10 kg (8.8+/-1.1 kg) in 54, including 21 with visceral heterotaxy. The superior caval vein (SVC) was anastomosed to the pulmonary arteries in a bidirectional fashion. To construct a channel draining the inferior caval vein (IVC), an extended polytetrafluoroethylene (ePTFE) tube was placed intraatrially (in 15 patients) or outside the heart (in 13), its diameter being 14 mm in two patients, 16 mm in 12, and 18 mm or greater in 14. A heterologous pericardial baffle was used for intraatrial rerouting in 12 patients. A pedicled autologous pericardial roll was tailored as an extracardiac conduit in 11 patients, and the pulmonary trunk was directly anastomosed to IVC orifice in three. RESULTS: Seven patients, including five with right isomerism, died in the intermediate term because of infection of the ePTFE tube in two, respiratory problems in three, atrioventricular valvar regurgitation in one, and pulmonary venous obstruction in one. Postoperative catheterization showed; SVC pressure, 11+/-2 mmHg without a pressure gradient between SVC and IVC; systemic ventricular end diastolic pressure, 5+/-2 mmHg; end diastolic volume, 122+/-54% of the anticipated normal value; ejection fraction, 0. 56+/-0.11; and cardiac index, 2.9+/-0.7 l/min per m(2). With the follow-up of 1-116 (35+/-31) months, the IVC channel has not become obstructive in all, except for one, in whom a pedicled pericardial roll was severely obstructed because of its tortuous extracardiac course crossing in front of the vertebrae. Postoperative growth was generally stable, although body weights and heights were smaller in the majority of patients when compared with the anticipated standards for Japanese children. CONCLUSION: TCPC can be justifiably established in small children. The use of autologous tissues seemed preferable for constructing the IVC channel unless anatomic orientation was unsuitable.

Blood Vessel Prosthesis Implantation↗
PubMed2000

Preoperative demonstration of the Adamkiewicz artery by magnetic resonance angiography in patients with descending or thoracoabdominal aortic aneurysms.

OBJECTIVE: Investigating the possibility of magnetic resonance angiography (MRA) to visualize the Adamkiewicz artery of as a preoperative study of thoracic aortic aneurysms. METHODS: From February 1998 to March 1999, 26 consecutive patients who had aneurysms of the thoracoabdominal or descending aorta underwent preoperative MRA to visualize the Adamkiewicz artery. Mean age was 60.5+/-11.5 years. Fifteen patients had non-dissecting aneurysm and 11 had aortic dissections. Nineteen patients underwent replacement of the aneurysms, four patients underwent endovascular stent-graft repair, and three patients were discharged without treatment of aneurysm. MRA was performed on a 1.5-T system (Magnetom, Siemens) and data acquisition was repeated two times following injection of gadolinium-DTPA. Source images were reconstructed with multiplanar reconstruction and maximum intensity projection. Criteria for the Adamkiewicz artery of were that the artery ascends from the dorsal branch of the intercostal or lumbar artery to the anterior mid-sagital surface of the spinal cord in the early phase. RESULTS: The Adamkiewicz arteries were demonstrated in 18 patients (69%). These arteries were originated from the left intercostal or lumbar arteries in 13 (72.2%) patients and from the right in 5 (27.8%) and from the Th8 branch in three, Th9 in seven, Th10 in two, Th11 in four, and L1 in two. All patients had graft replacement of the aorta using a partial bypass. All intercostal or lumber arteries, which were visualized as the origin of the Adamkiewicz artery, were reattached to the grafts. No spinal cord injury occurred. CONCLUSION: Preoperative detection the Adamkiewicz artery was possible by MRA and was very useful to reduce the incidence of ischemic injury of the spinal cord during surgery of the thoracoabdominal or descending aorta.

Adult↗
PubMed2000

Crossed cerebellocerebral diaschisis in patients with cerebellar stroke.

OBJECTIVES: We performed single-photon emission computed tomography (SPECT) to investigate crossed cerebellocerebral diaschisis (CCCD) in patients with cerebellar stroke. MATERIAL AND METHODS: Fifteen patients with unilateral cerebellar stroke underwent SPECT of the brain with N-isopropyl-p-[123I] iodoamphetamine (123I-IMP). Regional cerebral blood flow (rCBF) was measured by the autoradiographic method. Regions of interest were defined in the cerebral cortex, striatum, thalamus and cerebellum to compare structures (contralateral to the cerebellar lesion) with counterparts ipsilateral to the stroke. RESULTS: In the frontal and parietal cortices, especially the posterior superior frontal, anterior midfrontal, precentral, postcentral, and supramarginal areas, rCBF contralateral to the lesion was significantly lower than on the side of the lesion (showing CCCD). CONCLUSION: This CCCD phenomenon is important to be aware of in clinical reading of images.

Aged↗
PubMed2000

Postbypass pulmonary artery pressure influences respiratory system compliance after ventricular septal defect closure.

It is reported that surgical correction of left-to-right shunt improves respiratory function in paediatric cardiac patients. However, such correction sometimes does not result in an improvement of respiratory compliance. The purpose of this study was to look for factors determining changes in respiratory system compliance (Crs) in patients who underwent closure of ventricular septal defect (VSD closure). In a prospective study, 17 children (< 10 kg) who underwent VSD closure were enrolled. They were divided into two groups, according to postbypass mean pulmonary artery pressure (mPAP). The patients were allocated to Group C if mPAP was < or = 18 mmHg (n=12) and to Group PH if > 18 mmHg (n=5). We compared the ratio of postoperative Crs to preoperative Crs (Cpost/Cpre) between the groups. A multiple occlusion technique was used to measure Crs. The Cpost/Cpre in group C was larger than that in group PH (1.11+/-0.17 vs. 0.81+/-0.12, P<0.01). There was a correlation between postbypass mPAP and Cpost/Cpre (r(s)=0.49, P<0.05), but no correlation was noted between preoperative mPAP, Qp/Qs or Rp/Rs and Cpost/Cpre. We concluded that high postbypass mPAP was associated with a perioperative decrease in Crs after VSD closure.

Blood Pressure↗
PubMed2000

Met/HGF receptor modulates bcl-w expression and inhibits apoptosis in human colorectal cancers.

The met proto-oncogene is the tyrosine kinase growth factor receptor for hepatocyte growth factor. In the present study, we investigated the role of met expression on the modulation of apoptosis in colorectal tumours. The gene expressions of c-met and the anti-apoptotic bcl-2 family, including bcl-2, bcl-x(L)and bcl-w, were analysed in human colorectal adenomas and adenocarcinomas by using a quantitative polymerase chain-reaction combined with reverse transcription. In seven of 12 adenomas and seven of 11 carcinomas, the c-met gene was overexpressed. The bcl-w, bcl-2 and bcl-x(L)genes were over-expressed in nine, five and six of 12 adenomas and in five, two and seven of 11 carcinomas, respectively. The c-met mRNA level in human colorectal adenomas and carcinomas was correlated with bcl-w but not with bcl-2 or with bcl-x(L)mRNA level. The administration of c-met-antisense oligonucleotides decreased Met protein levels in the LoVo human colon cancer cell line. In the case of c- met -antisense-treated cells, apoptotic cell death induced by serum deprivation was more prominent, compared to control or c-met -nonsense-treated cells. Treatment with c-met-antisense oligonucleotides inhibits the gene expression of bcl-w in LoVo cells. On the other hand, the gene expression of bcl-2 or bcl-x(L)was not affected by treatment with c-met-antisense oligonucleotides. These findings suggest that Met expression modulates apoptosis through bcl -w expression in colorectal tumours.

Adenocarcinoma↗
PubMed2000

A surgically treated case of Takayasu's arteritis complicated by aortic dissections localized in the ascending and abdominal aortae.

Because complication by aortic dissection is markedly rare in patients with Takayasu's arteritis, a limited number of reports have been published regarding surgically treated cases of Takayasu's arteritis that is complicated by aortic dissection. When graft replacement of the ascending aorta and aortic arch and extra-anatomic bypass grafting were performed in a 72-year-old japanese woman with Takayasu's arteritis, which was complicated by aortic dissections localized in the ascending and abdominal aortae, the postoperative course of this patient was satisfactory. It was considered that the media became friable in this patient because of the presence of Takayasu's arteritis and that hypertension that persisted for a long time caused the independent development of aortic dissections in the ascending and abdominal aortae.

Aged↗
PubMed2000

Reduction of hydroxamic acids to the corresponding amides catalyzed by rabbit blood.

1. The hydroxamic acids N-hydroxyphenacetin and N-hydroxy-2-acetylaminofluorene were reduced to the corresponding amides, phenacetin and 2-acetylaminofluorene respectively by rabbit blood supplemented with both NAD(P)H and FAD. These reducing activities were found in erythrocytes but not in plasma, and were sensitive to inhibition by carbon monoxide and oxygen. When blood or erythrocytes were boiled, these activities were not abolished. 2. Haemoproteins such as haemoglobin and catalase exhibited the reductase activity in the presence of both NAD(P)H and FAD under anaerobic conditions. The activity was not abolished when the haemoproteins were boiled. 3. Haematin showed a significant reducing activity in the presence of these cofactors. The activity of haematin was also observed with the photochemically reduced form of FAD. 4. The reduction system in blood was composed of NAD(P)H, FAD and haemoglobin. Reduction appears to proceed in two steps, i.e. the reduction of FAD by NADH or NADPH, followed by the non-enzymatic reduction of the hydroxamic acids to the amides by reduced FAD, catalyzed by the haem group of haemoglobin in rabbit erythrocytes.

2-Acetylaminofluorene↗
PubMed2000

Reduction of stilbene oxide and styrene oxide to the corresponding alkenes by intestinal bacteria.

1. This study provides the first evidence that stilbene oxide and styrene oxide are reductively metabolized to the corresponding alkenes by intestinal bacteria in animals. 2. When trans- or cis-stilbene oxide were incubated with the caecal contents of rat under anaerobic conditions, both trans- and cis-stilbene were isolated from the incubation mixture. Styrene oxide was also reduced to styrene by rat caecal contents. 3. Caecal contents of mouse, hamster and guinea pig also exhibited alkene oxide reductase activities toward cis- and trans-stilbene oxides, and styrene oxide. In contrast, liver microsomes or cytosol exhibited no epoxide reductase activities toward these substrates. 4. Seven pure strains of intestinal bacteria exhibited alkene oxide reductase activities of varying degrees under anaerobic conditions, with the highest activity being observed in Clostridium sporogenes. 5. Cell-free extracts of either the intestinal bacteria in rat caecal contents or C. sporogenes exhibited reductase activity when supplemented with both NAD(P)H and FMN under anaerobic conditions. Reductase activity was also observed on addition of the photochemically reduced form of FMN instead of both NAD(P)H and FMN.

Animals↗
PubMed2000

Highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans show a distinct localization pattern in the tissues of Zea mays L.

Polyclonal antibodies which recognized highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans and did not cross-react with each other, were raised in order to examine localization of these epitopes in internodes of maize. Immunofluorescent labeling revealed different pattern between two succeeding developmental stages. The hsGAX epitope was localized evenly in primary walls in all tissue types, and strongly in unlignified secondary walls in phloem. However, lignified secondary walls in protoxylem, parenchyma and a part of fibers were faintly labeled with this epitope. Moreover, the epitope showed limited binding in lignified parenchyma and fiber walls at ultrastructural level. Low-branched xylan epitope was localized evenly throughout lignified walls in all tissue types. This epitope was also localized only in lignified walls of other organs such as leaf, root apex and dark-grown mesocotyl. Low-branched xylans are significantly related to lignification. Localization of hsGAX epitope in their organs was similar to that in internodes. The hsGAX epitope was distributed both in unlignified walls of all tissues and in lignified walls of parenchyma and annular thickening of protoxylem. We propose that hsGAX has separate functions in lignified and unlignified tissues. In conclusion, at tissue level, hsGAX is localized mainly in unlignified walls, and low-branched xylans in lignified walls.

Antibody Specificity↗