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Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Tricuspid valve replacement using right heart bypass in patient with liver cirrhosis].

A successful case with liver cirrhosis underwent re-tricuspid valve replacement (TVR) using right heart bypass is reported herein. A 59-year-old lady previously undergone tricuspid valve replacement with bioprosthetic valve had suffered from exertional fatigue as the feature of congestive heart failure. She also presented severe liver dysfunction owing to chronic hepatitis and cardiac liver cirrhosis. She was diagnosed with structural deterioration of bioprosthesis in tricuspid position. She underwent re-TVR with right heart bypass consisted of centrifugal pump, heparin coating circuit and blood reservoir. This system lacked of membranous oxygenator in order not to activate various kinds of chemical mediator which leads to postoperative liver dysfunction. Postoperative course was uneventful and she is doing well 1 year after the operation. Although the mortality of the TVR in the patient with cirrhosis remains still high, this new technique seems to provide better outcome in this kind of patients.

Bioprosthesis↗
PubMed2001

[Anesthetic management for the correction of pectus excavatum using pectus bar under video-assistance].

We report anesthetic management for a child undergoing Nuss operation, a minimally invasive operation which requires neither cartilage incision nor its resection for correction of pectus excavatum. The patient was a 7-year-old boy with the funnel index 5 and the mediastinal shift to the left. General anesthesia with endotracheal intubation was induced and maintained with nitrous oxide, sevoflurane and fentanyl. Thoracic epidural anesthesia was used with 0.125% bupivacaine to supplement analgesia. When the curved bar was passed under the sternum with the aid of an endoscope, sinus tachycardia occurred and continued for 5 minutes but subsided without medication. Otherwise operative course was uneventful with negligible blood loss. After surgery, the patient was kept at bed rest for 2 days, receiving epidural patient-controlled analgesia combined with sedation with midazolam with good results. He was allowed to sit 3 days, to walk 5 days and discharged 10 days postoperatively.

Analgesia, Patient-Controlled↗
PubMed2001

Differences in adaptation to growth of children between internal thoracic artery and saphenous vein coronary bypass grafts.

BACKGROUND: It is not known how the internal thoracic artery (ITA) and saphenous vein graft (SVG) adapts to somatic growth of pediatric patients who underwent coronary artery bypass grafting (CABG). METHODS: Twenty-two ITAs and 6 SVGs in 17 patients who underwent at least three postoperative catheterizations with biplanar cineangiography and followed for a minimum of 5 years were evaluated. We evaluated the length, diameter and curvature of the grafts by cineangiographies which were performed at 1 month, 1 year, 5 years and more than 5 years postoperatively. RESULTS: The length of the ITA (1-month: 117+/-31 mm, 1-year: 134+/-32 mm, 5-years: 146+/-28 mm, and >5-years: 155+/-34 mm, p=0.032) and diameter of the ITA (1.4+/-0.4 mm, 2.0+/-0.7 mm, 2.3+/-0.6 mm and 2.6+/-0.6 mm, p<0.0001) significantly increased over time, but neither the length nor diameter of the SVG length: 121+/-33 mm, 119+/-29 mm, 119+/-25 mm and 126+/-1 mm, p=0.9907; diameter: 4.1+/-1.0 mm, 3.9+/-0.7 mm, 4.0+/-0.8 mm and 3.3+/-0.4 mm, p=0.5784) increased. Although the ITA exhibited no change in curvature over time (1 month: 1.15+/-0.07, late: 1.15+/-0.07, p=0.8490), the curvature of the SVG significantly decreased over time (1 month: 1.42+/-0.19 and late: 1.25+/-0.16, p=0.0277). The percent segmental length of ITAs were changed little from early to late after CABG (1 month: proximal: 33.7+/-7.0%, middle: 33.3+/-7.9% and distal: 32.9+/-7.9%, vs late: 34.3+/-7.2%, 33.2+/-7.9% and 32.5+/-7.9%, p=0.937). CONCLUSIONS: ITAs grow in proportion to somatic growth, while SVGs course in a more linear fashion in adapting to patient growth.

Adaptation, Physiological↗
PubMed2001

[Perioperative management of a child with congenital nephrogenic diabetes insipidus].

The key point in perioperative management of a patient with congenital nephrogenic diabetes insipidus is fluid and electrolytes management. Since the urine of these patients consists mainly of solute free water, replacement fluids should be fluids which provide free water. A 2-year-old girl with congenital nephrogenic diabetes insipidus was scheduled for dental extraction. Her daily fluid intake was 10 liter. She had a history of recurrent fever, polyuria and polydipsia since 2 months of age. Her previous perioperative course for gastric volvulus at another hospital was complicated with postoperative hyponatremia and convulsion. A venous line was secured the day before surgery and 5% dextrose in water was infused at a rate of 12 ml.kg-1.hr-1. Intraoperative infusion was mainly with 5% dextrose in water combined with maintenance fluid. Five hours after surgery oral intake was started. Her intraoperative electrolytes levels were low (Na 133 mEq.l-1, K 2.8 mEq.l-1), but otherwise her perioperative course was uneventful.

Anesthesia, Inhalation↗
PubMed2001

[Developing the best and the brightest in academic surgery for next generation].

Major advances have been achieved in surgery during the past century and further dynamic changes are expected along with progress in immunology, tissue and mechanical engineering, etc. in the 21st century. However, fewer medical students will choose the surgical field as their specialty, primarily due to the long training period, and inadequate income as compared to the heavy workload. To recruit the best and the brightest students in surgery, early exposure to the positive aspects of the surgical field is desirable. The training system should be further refined, and a sufficient number of positions with appropriate remuneration must be mode available.

Education, Medical, Graduate↗
PubMed2001

[Recovery characteristics of propofol anesthesia in pediatric outpatients; comparison with sevoflurane anesthesia].

We compared recovery characteristics of propofol anesthesia with those of sevoflurane anesthesia in pediatric outpatients. One hundred and four children, 3 months to 6 years of age, ASA physical status 1 or 2, were randomly assigned to following four groups; sevoflurane (group S), propofol (group P), sevoflurane with premedication (group MS), or propofol with premedication (group MP). Midazolam 0.5 mg.kg-1 and famotidine 1 mg.kg-1 were administered orally 30 min before the induction in the MS and MP group. Recovery from anesthesia, agitation, and postoperative pain were evaluated. The time intervals from the end of surgery to extubation and to discharge from the hospital were recorded. The incidence of vomiting and use of analgesic drugs were also checked. The emergence from anesthesia was slower with propofol anesthesia than with sevoflurane anesthesia, but the time to discharge from the hospital was not significantly different among the four groups. Incidence of agitation was higher in S group compared with P group, but there were no differences between MS and MP. Postoperative pain was similar among the four groups. There were no differences in the incidence of vomiting. Propofol anesthesia provided slower emergence and less agitation compared with sevoflurane anesthesia.

Anesthesia Recovery Period↗
PubMed2001

[Perioperative management of twins with prenatally diagnosed congenital diaphragmatic hernia].

Congenital Diaphragmatic Hernia (CDH) occurs in one of every 2000-3000 births, and most of them are sporadic, and therefore recognized as a circumstantial event. But its occurrence in 85 children among the 40 families is also reported, and some reports suggest that an autosomal recessive gene may be responsible for this disease. We experienced identical twins (babies A and B) both with prenatally diagnosed CDH. They were delivered by emergent cesarean section at 33 weeks of gestation with birth weight of 1857 g and 1561 g, respectively. They were intubated immediately after birth, and ventilated with high frequency oscillation. Baby A presented persistent pulmonary hypertension of newborn, and received nitric oxide inhalation. At the age of 2 days, both of them were stabilized and underwent repair of CDH. After the repair, baby A developed perforation of ileum, airway bleeding and retinopathy of prematurity (ROP), and needed 28 days before extubation. Baby B also developed ROP, but had no other problem, and the trachea was extubated at the age of 12 days. They are the seventh pair reported in the world literature.

Diseases in Twins↗
PubMed2001

[Aortoesophageal fistula due to ruptured thoracic aortic aneurysm: case report of successful primary reconstruction of esophagus].

We report a successful surgical case of 78-year-old woman with aortoesophageal fistula subsequent to the operation for sealed rupture of thoracic aortic aneurysm. She underwent one-stage operation consisted of esophagectomy, transmediastinal interposition of the stomach and esophagogastroanastomosis, to re-establish the gastrointestinal tract. The patient recovered well postoperatively without infection.

Aged↗
PubMed2000

Ten-year experience of chordal replacement with expanded polytetrafluoroethylene in mitral valve repair.

BACKGROUND: Mitral valve repair is the procedure of choice to correct mitral regurgitation (MR). Although chordal replacement with expanded polytetrafluoroethylene (ePTFE) has been widely accepted to repair anterior mitral prolapse and other difficult situations, the long-term results of the repair and the fate of ePTFE have not been delineated. METHODS AND RESULTS: From July 1988 to April 1999, 74 patients (49 males, 25 females) aged 17 to 77 years (mean age 55. 3+/-14.8 years) underwent mitral valve repair with chordal replacement with ePTFE. The follow-up period was from 6 months to 11. 3 years (mean 4.6+/-3.2 years). The causes of MR were degenerative in 65 patients (88%) and infective in 9 (12%). Three patients had active infective endocarditis. Valve lesions were anterior in 35 patients, posterior in 10, and both anterior and posterior in 29. Various procedures for plasty of leaflets were necessary in 37 patients (50%). Atrial fibrillation was associated in 38 patients (51%), and the maze procedure has been performed in a selected group of 30 patients (41%) since July 1992. There was 1 in-hospital death (1.4%) and 3 late cardiac deaths (4.1%). More than moderate MR developed in 12 patients (17%) during the follow-up period. Three of these patients required early reoperation within 1 year due to hemolysis. Two patients underwent mitral valve replacement at 6 and 8 years after repair, respectively. The actuarial reoperation-free rates at 5 and 10 years were 94.3+/-2.8% and 81.7+/-9.1%, respectively. Sinus rhythm was restored in 21 patients (70%) with the maze procedure. There was only 1 thromboembolic episode (0. 3%/patient-y) in a patient with atrial fibrillation who did not undergo the maze procedure. Event-free survival rates as assessed by the freedom from cardiac death, thromboembolism, reoperation, and anticoagulation-related hemorrhage at 5 and 10 years were 91.3+/-3. 4% and 71.6+/-9.7%, respectively. There was no relationship between recurrent MR and the change of ePTFE. Structural analysis of the ePTFE resected during reoperation revealed no calcification and showed remaining flexibility and pliability. Protein infiltration was observed in the ePTFE, and collagenous proliferation was recognized at the site of fixation to the valve leaflet and the papillary muscle. The surface of the ePTFE was completely endothelialized, which may induce antithrombogenicity. CONCLUSIONS: The long-term durability and biological adaptation of ePTFE as artificial chordae for mitral valve repair of MR were proved for >10 years.

Adolescent↗
PubMed2000

Retrograde cerebral perfusion in human brains.

Retrograde cerebral perfusion via the superior vena cava during deep hypothermic circulatory arrest has evolved as a means of cerebral protection in aortic-arch surgery. We showed, with use of fluorescein retinal angiography, that during retrograde cerebral perfusion, fluorescein injected into the superior vena cava entered the retinal venules, flowed to the capillaries, and subsequently, to the retinal arterioles. Since the retina is embryologically part of the brain, we conclude that this procedure does allow blood to perfuse in a retrograde way through the human brain.

Adult↗
PubMed2000

Metabolic activation of the proestrogens trans-stilbene and trans-stilbene oxide by rat liver microsomes.

A liver microsome-mediated activation of the proestrogens trans-stilbene and trans-stilbene oxide was found in this study. trans-Stilbene and trans-stilbene oxide were negative in estrogen reporter assay using estrogen-responsive human breast cancer cell line MCF-7 and growth assay in rat pituitary tumor cell line MtT/E-2. However, these compounds exhibited estrogenic activity after incubation with liver microsomes of 3-methylcholanthrene-treated rats in the presence of NADPH. In contrast, cis-stilbene and cis-stilbene oxide did not show estrogenic activity after such incubation. When trans-stilbene was incubated with the liver microsomes of 3-methylcholanthrene-treated rats in the presence of NADPH, two metabolites were detected by HPLC. They were identified unequivocally as trans-4-hydroxystilbene and trans-4, 4'-dihydroxystilbene by mass and UV spectral comparison with authentic samples. The oxidase activity of the liver microsomes toward trans-stilbene was inhibited by SKF 525-A and alpha -naphthoflavone. Minor activity was observed when liver microsomes of untreated or phenobarbital-treated rats were used instead of those from 3-methylcholanthrene-treated rats. trans-4-Hydroxystilbene and trans-4,4'-dihydroxystilbene exhibited significant estrogenic activities. These results suggest that the estrogenic activities of trans-stilbene and trans-stilbene oxide were due to formation of hydroxylated metabolites.

Animals↗
PubMed2000

Mutations of the bak gene in human gastric and colorectal cancers.

The Bcl-2 homologue Bak is a potent inducer of apoptosis. We performed PCR-based single-strand conformational polymorphism and sequencing analysis of the entire coding region of the bak gene (exons 2-6) in 24 primary gastric cancers (6 early-stage and 18 advanced-stage cancers) and 20 primary colorectal cancers (6 early-stage and 14 advanced-stage cancers). The data herein demonstrate, for the first time, the mutation of the bak gene in gastric and colorectal cancers. Missense bak gene mutations were observed in 3 of 24 (12.5%) gastric cancers and 2 of 20 (10.0%) colorectal cancers. Sequence alterations without amino acid alteration were observed 1 of 24 (4.2%) gastric cancers and 2 of 20 (10.0%) colorectal cancers. Mutations in the bak gene were observed only in advanced-stage gastrointestinal cancers but not in early-stage cancers. Our observations suggest that mutations in this gene predispose bearers to the development of gastrointestinal malignancies in at least a subset of the cases.

Colorectal Neoplasms↗
PubMed2000

Deficiency in mitochondrial aldehyde dehydrogenase increases the risk for late-onset Alzheimer's disease in the Japanese population.

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) deficiency is caused by a mutant allele in the Mongoloids. To examine whether genetic constitutions affecting aldehyde metabolism influence the risk for late-onset Alzheimer's disease (LOAD), we performed a case-control study in the Japanese population on the deficiency in ALDH2 caused by the dominant-negative mutant allele of the ALDH2 gene (ALDH2*2). In a comparison of 447 patients with sex, age, and region matched nondemented controls, the genotype frequency carrying the ALDH2*2 allele was significantly higher in the patients than in the controls (48.1% vs 37.4%, P = 0.001). Logistic regression analysis indicates that carriage of the ALDH2*2 allele is an independent risk for LOAD of the epsilon4 allele of the apolipoprotein E gene (APOE-epsilon4) (P = 0.002). Moreover, the odds ratio for LOAD in carriers of the ALDH2*2 allele was almost twice that in noncarriers, irrespective of status with regard to the APOE-epsilon4 allele. Among patients homozygous for the APOE-epsilon4 allele, age at onset of LOAD was significantly lower in those with than without the ALDH2*2 allele. In addition, dosage of the ALDH2*2 allele significantly affected age at onset of patients homozygous for the APOE-epsilon4 allele. These results indicate that the ALDH2 deficiency is a risk for LOAD, synergistically acting with the APOE-epsilon4 allele.

Age of Onset↗
PubMed2000

Roles of melatonin in gonadal maturation of underyearling precocious male masu salmon.

Testicular maturation of underyearling precocious male masu salmon (Oncorhynchus masou) is affected by photoperiod. It is accelerated by a short photoperiod (light-dark cycles of 8:16 h; LD 8:16) and delayed by a long photoperiod (LD 16:8). Circulating melatonin levels are high during the night and low during the day:the duration of the nocturnal elevation is longer under a short than under a long photoperiod, suggesting mediation of photoperiodic signals by melatonin. This study examined whether melatonin administration mimics short photoperiodic effects and whether it accelerates the testicular development of underyearling male masu salmon reared under a long photoperiod. Fish were randomly selected in June and were divided into two groups. They were reared under LD 16:8 (lights on 04:00-20:00 h) and fed pellets sprayed with melatonin (0.5 mg melatonin/kg body weight/day) or vehicle once a day at 11:00 h until October. The plasma melatonin profile of the melatonin-treated group was similar to that expected under a short photoperiod. Melatonin treatment had a stimulatory effect on the gonadosomatic index and pituitary gonadotropin (GTH) I contents. Plasma testosterone levels were significantly higher in the melatonin-treated group than in the control group in August. However, spermiation was observed in October in both groups and no significant differences were observed in GTH II contents in the pituitary in the two groups throughout the experiment. These results suggest that mimicking a short photoperiod by melatonin administration stimulated testicular development but did not completely activate the brain-pituitary-gonadal axis in precocious male masu salmon. Thus, melatonin is suggested to be one of the factors that mediates the transduction of photoperiodic information to the brain-pituitary-gonadal axis.

Administration, Oral↗
PubMed2000

Intrasubject correlation between static scan and distribution volume images for [11C]flumazenil PET.

Accumulation of [11C]flumazenil (FMZ) reflects central nervous system benzodiazepine receptor (BZR). We searched for the optimal time for a static PET scan with FMZ as semi-quantitative imaging of BZR distribution. In 10 normal subjects, a dynamic series of decay-corrected PET scans was performed for 60 minutes, and the arterial blood was sampled during the scan to measure radioactivity and labeled metabolites. We generated 13 kinds of "static scan" images from the dynamic scan in each subject, and analyzed the pixel correlation for these images versus distribution volume (DV) images. We also analyzed the time for the [11C]FMZ in plasma and tissue to reach the equilibrium. The intra-subject pixel correlation demonstrated that the "static scan" images for the period centering around 30 minutes post-injection had the strongest linear correlation with the DV image. The ratio of radioactivity in the cortex to that in the plasma reached a peak at 40 minutes after injection. Considering the physical decay and patient burden, we conclude that the decay corrected static scan for [11C]FMZ PET as semi-quantitative imaging of BZR distribution is to be optimally acquired from 20 to 40 minutes after injection.

Adult↗
PubMed2000

Surgical considerations of occlusive lesions associated with Takayasu's arteritis.

OBJECTIVE: Takayasu's arteritis is an inflammatory vascular disease of unknown etiology that affects the aorta and its main branches, requiring surgical intervention due to occlusive lesions. We studied early and late surgical results. METHODS: Between 1979 and December 1998, 46 patients--1 man and 45 women aged 15 to 72 years (mean: 46 +/- 13 years)--with occlusive lesions caused by Takayasu's arteritis underwent surgery. Preoperative steroids were administered to 22 patients having inflammation. Diagnosis indicating surgery included obstructive cervical vessel disease in 13 patients, obstructive coronary artery disease in 19, aortic coarctation in 15, and abdominal branch stenosis in 3. Surgical procedures involved bypass grafting in 31 (cervical vessel bypass in 13, ascending-abdominal aortic bypass in 4, axillary artery-abdominal aortic bypass in 10, descending-abdominal aortic bypass in 1, abdominal branch bypass in 3), coronary artery bypass grafting in 10, and coronary ostial endarterectomy in 9. RESULTS: Four (8.7%) died during hospitalization. Follow-up ranged from 1 to 240 months (mean: 117 months). Eight suffered late deaths and 6 patients died of cardiovascular problems. The total actuarial survival rate was 76.2% at 5 years and 70.5% at 10 years. CONCLUSIONS: Steroid therapy before and after surgery appears to affect the overall prognosis positively in patients with Takayasu's arteritis.

Adolescent↗
PubMed2000

Results from coronary artery bypass surgery combined abdominal aortic aneurysm repair.

OBJECTIVE: Complication from coronary artery disease is a major cause of mortality and morbidity in patients undergoing abdominal aortic aneurysm repair. We report our results from coronary artery bypass surgery performed in combination with abdominal aortic aneurysm repair in patients with coronary artery disease and abdominal aortic aneurysm, each being an indication for an emergency operation. METHODS: Seventeen patients underwent combined coronary artery bypass surgery and abdominal aortic aneurysm repair. The mean age of the patients was 67.6 +/- 5.2 years. Four had left main disease, 8 patients had triple-vessel disease, and 12 had a prior myocardial infarction. The average left ventricular ejection fraction was 0.49 +/- 0.13. The average abdominal aortic aneurysm diameter was 6.2 +/- 1.0 cm (range 4.5-8.0 cm). Thirteen patients underwent coronary artery bypass surgery followed by abdominal aortic aneurysm repair after discontinuation of cardiopulmonary bypass. In the remaining four patients, including one patient with severe left ventricular dysfunction, cardiopulmonary bypass was continued as a circulatory assist until the abdominal aortic aneurysm repair was completed. The left internal thoracic artery was used in 14 patients, and the right internal thoracic artery in one patient. RESULTS: Postoperative surgical complications occurred in three patients (bleeding in one patient requiring reoperation, abdominal subcutaneous wound infection in another and transient neural disorder in the others). There were no surgical or in-hospital death. There was no late cardiac complication and no late cardiac death after a mean of 29 months follow-up. CONCLUSIONS: We concluded that combined surgery was reasonable for selected patients with combined coronary artery disease and abdominal aortic aneurysm, each of which is an indication for an urgent operation. The aortic aneurysm repair during cardiopulmonary bypass for patients with severe left ventricular dysfunction was safe and effective.

Aged↗