Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 541 records · Page 30Linked to original sources

PubMed1993

Long-term appraisal of coronary bypass operations in familial hypercholesterolemia.

Long-term results of coronary artery bypass grafting (CABG) in consecutive 32 patients with familial hypercholesterolemia, 6 homozygotes and 26 heterozygotes between 1976 and 1990, were analyzed. Seventeen patients in the early series underwent CABG with vein grafts alone. Subsequently, 15 patients underwent CABG with internal mammary artery grafting to the left anterior descending artery and received intensive lipid-lowering treatments early after CABG. All homozygotes and 1 heterozygote received intermittent low-density lipoprotein apheresis after CABG. There was only one late noncardiac death (3%), and the actuarial rates of freedom from cardiac events (myocardial infarction, cardiac death, and angina pectoris) were 60% at 5 and 10 years for homozygotes, and 87% and 73% for heterozygotes. The cardiac event-free curve for the heterozygous familial hypercholesterolemia group was comparable with that for the random age-matched subset of patients without familial hypercholesterolemia who underwent CABG during the same period. Two of 3 homozygotes and 4 of 14 heterozygotes in the early series had one or more cardiac events, whereas no patients in the late period had cardiac events. The patency rate of internal mammary artery grafts to the left anterior descending artery from 1 to 3 years after CABG was significantly higher than that of vein grafts to the left anterior descending artery (92 versus 45%; p < 0.05). Abdominal aortic aneurysm developed postoperatively in 2 homozygotes and 2 heterozygotes without sufficient cholesterol reduction. In conclusion, internal mammary artery grafting in combination with postoperative intensive lipid-lowering treatments, including low-density lipoprotein apheresis, may provide acceptably good long-term results of coronary revascularization in patients with FH.

Actuarial Analysis↗

PubMed1993

Hyperoxia decreases cyclooxygenase activity in endothelial cells.

We examined the effect of hyperoxia on arachidonic acid (AA) metabolism in bovine carotid artery endothelial cells (CAEC) and pulmonary artery endothelial cells (PAEC). Confluent monolayers were exposed to hyperoxic gases (95% O2 or 60% O2) from 12-72 h. Control cells were incubated under normoxic condition (air-5% CO2). After exposure of the cells to normoxic or hyperoxic conditions, prostaglandin (PG) synthesis activity was analyzed in cell homogenates using thin layer chromatography; release of 6-keto-PGF1 alpha, a stable metabolite of PGI2, into the culture medium was measured using a radioimmunoassay. The major metabolites formed from exogenously supplied 14C-AA were 6-keto-PGF1 alpha and a small amount of PGE2. Hyperoxia (95% O2) decreased the synthesis of these cyclooxygenase products beginning at 24 h; moderate hyperoxia (60% O2) had no such effect. There was no significant difference between CAEC and PAEC with respect to the depletion effect of hyperoxia. After 72 h of exposure to 95% O2, endothelial injury was observed in CAEC but not in PAEC. We conclude that hyperoxia decreases cyclooxygenase activity in endothelial cells, and that this decrease is dependent on the severity of the hyperoxia. In addition, CAEC are more susceptible to hyperoxia-induced injury than PAEC. The depletion of cyclooxygenase activity and the resultant effect on PGI2 and PGE2 production may be a factor in the development of hyperoxia-induced endothelial injury.

Animals↗

PubMed1993

Macrocyclization of polysaccharides visualized by electron microscopy.

Topological features of the polysaccharides schizophyllan, l-carrageenan and gellan gum were studied using electron microscopy. Electron micrographs of schizophyllan not subjected to any thermal or solvent composition history destabilizing the triple helix, show stiff, linear chains consistent with the structure being triple helical and with contour length proportional to the molecular weight in solution. A blend of linear, cyclic and hairpin topologies and higher molecular weight clusters were observed after renaturation, i.e. return to conditions favouring the triple helical structure, from solvent conditions dissociating the triple helix. Electron micrographs of l-carrageenan in salt-free solution reveal linear extended structures. Addition of 0.15 M LiI to the solution before preparation for electron microscopy, i.e. salt conditions that favour ordering but not gelation, yields a large fraction of cyclic structures with circumference of different lengths. Likewise, adding KCl to aqueous gellan gum changes their appearance from dispersed polymers to suprastrands with several associated chains. Macrocyclic species can also be observed in gellan gum after the addition of a gel-promoting salt. The tendency to form macrocyclic structures in competition with intermolecular aggregates is determined by the three factors: (1) chain stiffness relative to overall length; (2) parallel or antiparallel alignment of interacting chain segments; and (3) polymer concentration. The present study indicates that electron microscopy provides information about the topology adopted by polysaccharides.

Carbohydrate Conformation↗

PubMed1993

Penetration of a screw into the thoracic aorta in anterior spinal instrumentation. A case report.

With recent advances in spine surgery, spinal instrumentation has allowed the introduction of varied new devices and techniques, expanding its potentials. Yet this has also led to the incidence of unexpected complications. The current article reports on a serious case the authors recently experienced, in which a screw used for the instrumentation of the thoracic vertebra penetrated the aorta.

Aorta, Thoracic↗

PubMed1993

Tumor invasion of the chest wall in lung cancer: diagnosis with US.

The accuracies of ultrasonography (US) and computed tomography (CT) for determining tumor invasion of the chest wall in lung cancer were compared in a retrospective study of 120 patients. US findings were evaluated preoperatively according to the following criteria: disruption of pleura, extension through the chest wall, and fixation of tumor during breathing. CT findings were evaluated with the following criteria: obtuse angle of the mass to the pleural surface, more than 3 cm contact with the pleural surface, and visible pleural thickening associated with the mass. Chest wall invasion was judged as positive when at least two of the three findings were present with either technique. Nineteen of the 120 patients had chest wall invasion by tumor. The sensitivity of US was 100% and the specificity was 98%. The sensitivity of CT was 68% and the specificity was 66%. The accuracy of US and CT were 98% and 67%, respectively.

Adult↗

PubMed1993

Incomplete interlobar fissures: bronchovascular analysis with CT.

Thin-section computed tomographic scans of both lungs in 154 patients, including seven cadavers, with lung cancer (n = 37), diffuse (n = 32) or inflammatory (n = 30) lung disease, other proved or suspected disease (n = 23), or healthy lungs (n = 32) were analyzed to determine the frequency of incomplete interlobar fissure (IIF). An IIF was defined as a discontinuous linear shadow that remained in contact with the chest wall. An IIF was found in 128 of 154 right lungs (83.1%) and 77 of 154 left lungs (50.0%). Some bronchovascular structures crossed or passed through two contiguous lobes in the fused area. The most common bronchovascular structure associated with an IIF was a pulmonary vein; this association was found in 87 right lungs (56.5%) and 20 left lungs (13.0%). An IIF was traversed by a pulmonary artery in only seven right lungs and 13 left lungs or by a bronchus in only three lungs. It is concluded that recognition of an IIF might improve understanding of the spread of pulmonary disease.

Bronchi↗

PubMed1993

[Studies on structures of urinary metabolites of quinotolast, a new oral anti-allergics].

Metabolites of quinotolast in the human, rat and dog urine were isolated chromatographically and their structures were determined spectroscopically. para-Hydroxy substitution to the phenoxyl function of quinotolast, and glucoside or glucuronide conjugate to its tetrazole ring were observed.

Animals↗

PubMed1993

15-Ketoprostaglandin delta 13-reductase activity in bovine ocular tissues.

The present study provides the first evidence for delta 13-reduction of 15-ketoprostaglandins (15-keto-PGs) by bovine ocular tissues. The 9,000xg supernatants of cornea, iris, ciliary body, retina, and RPE-choroid except lens exhibited delta 13-reductase activity toward 15-keto-PG E2 and F2 alpha in the presence of NADPH or NADH as an electron donor. Among the tissues tested, the highest activity was observed in ciliary body and iris, followed by RPE-choroid, retina, and cornea. The NADPH- and NADH-linked double bond reductase activities were inhibited by dicumarol, quercitrin, indomethacin and disulfiram, but not by potassium cyanide. NADPH-linked 15-keto-PG F2 alpha delta 13-reductase was purified from bovine iris-ciliary body cytosol by fractionation with ammonium sulfate and high performance liquid chromatography (HPLC) with TSK gel DEAE-5PW, and TSK gel Blue-5PW. The purified enzyme was homogenous by the criterion of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its molecular weight was estimated to be about 57,000 by electrophoresis, and about 55,000 by gel filtration HPLC with Superose 12.

15-Oxoprostaglandin 13-Reductase↗

PubMed1993

The central projections of the monkey tooth pulp afferent neurons.

Transganglionic transport of horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) entrapped in hypoallergenic polyacrylamide gel was used to study the patterns of termination of primary afferents that innervate the upper and lower tooth pulps within the trigeminal sensory nuclear complex (TSNC) of the monkey. HRP:WGA injections were also made into the lower incisors and molars, in order to examine the topographic arrangement of pulpal afferent projections. HRP-labeled pulpal afferents innervating lower and upper teeth projected ipsilaterally to the rostral subnucleus dorsalis (Vpd) and caudal subnucleus ventralis (Vpv) of the nucleus principalis (Vp); the rostrodorsomedial (Vo.r) and dorsomedial (Vo.dm) subdivisions of the nucleus oralis (Vo); the dorsomedial subdivision of the nucleus interpolaris (Vi); and laminae I-II and/or V of the nucleus caudalis (Vc) at its rostralmost level. The HRP-labeled terminals from upper and lower pulpal afferents formed a rostrocaudal column from the midlevel of Vp to the rostral tip of Vc. The label in Vp and Vo was considerably dense, but the column of terminals was interrupted at the Vpd-Vpv transition. The label in Vi and Vc was much less dense compared to that in the rostral nuclei, and the column of terminals was interrupted frequently. The representation of the upper and lower teeth in TSNC was organized in a somatotopic fashion that varied from one subdivision to the next, though their terminal zones overlapped within Vpd. The upper and lower teeth were represented in Vpv, Vo.r, Vo.dm, Vi, and Vc in a ventrodorsal, dorsoventral, lateromedial, lateromedial, and lateromedial sequence, respectively. Topographic arrangement was also noticed for the projections of pulpal afferents from the lower incisors and molars: The representations of the lower incisors and molars in Vpv, Vo.r, Vo.dm, Vi, and Vc were organized in a lateromedial, dorsoventral, ventrodorsal, ventrodorsal, and lateromedial sequence, respectively. The present results indicating sparse projections from pulpal afferents in the monkey's Vc are in good correspondence with a clinical report that trigeminal tractotomy just rostral to the obex has no significant effect on dental pain perception in patients. Furthermore, the present study indicates that projection patterns of pulpal afferents--which include the termination sites, the density of terminations between nuclei, and topographic arrangement--differ among animal species.

Afferent Pathways↗

PubMed1993

Purification of a 15-ketoprostaglandin delta 13-reductase from rat liver and its ability to reduce the double bond of xenobiotics.

A 15-ketoprostaglandin delta 13-reductase was purified to homogeneity from rat liver. The enzyme used NADPH much more effectively than NADH as an electron donor. The molecular weight was estimated to be 39,500 by electrophoresis and 42,000 by gel filtration. The Km apparent for 15-ketoprostaglandin F2 alpha was 213 nM. The enzyme was markedly inhibited by dicumarol, quercitrin, p-chloromercuribenzoic acid and indomethacin. The enzyme had an isoelectric point at pH 4.5 and a broad pH optimum. The enzyme also exhibited the double bond reductase activity toward several xenobiotics with the double bond adjacent to the carbonyl group.

15-Oxoprostaglandin 13-Reductase↗

PubMed1993

Hypothermic ventricular fibrillation with pulsatile coronary perfusion during repair of ventricular septal perforation following infarction.

Emergency or urgent surgery for ventricular septal perforation (VSP) following acute myocardial infarction still carries a high operative mortality rate. Hypothermic fibrillatory arrest studies without aortic cross-clamping and using continuous pulsatile coronary flow were performed to improve this result. Of 19 patients suffering from VSP, 12 underwent hypothermic (mean(s.d.) blood temperature 23.5(1.7) degrees C) ventricular fibrillation with concomitant pulsatile systemic and continuous coronary perfusion (group 1), and seven underwent deep hypothermic cardioplegic ischaemic arrest with systemic pulsatile perfusion alone (group 2). The two groups were comparable in terms of age, sex, location of infarction, number of coronary arteries involved, interval between infarction and surgery, and preoperative maximum enzyme levels and haemodynamics. Pulsatile flow with a mean(s.d.) pulse pressure of 48(13) mmHg was produced by an intra-aortic balloon pumping device in both groups. Operative exposure in the two groups was comparable. In group 1, mean(s.d.) cardiac output in the early postoperative period (within 3 h of procedure) was significantly higher than in group 2 (4.2(0.9) versus 2.6(0.7)lmin-1m-2, P < 0.01). The 30-day operative mortality rate was significantly lower in group 1 (8% (80% confidence interval 1-29%)) than in group 2 (57% (80% confidence interval 28-83%)) (P < 0.05). On the basis of these results, hypothermic fibrillatory arrest with continuous pulsatile coronary perfusion can be recommended for myocardial protection during surgery for VSP associated with severe heart failure or cardiogenic shock.

Aged↗

PubMed1993

[Cognitive function and its evaluation methods in Parkinson's disease--a study including RCPM and ERP].

In order to investigate features of cognitive impairment in idiopathic Parkinson's disease (PD) and suitable methods for the cognitive evaluation of patients with PD, 23 PD patients and 15 normal control subjects were studied using neuropsychological tests and auditory event-related potential (ERP). The two groups did not differ from each other in age or education. Clinical severity of the patients based on Hoehn & Yahr's staging ranged from stage I to IV: 7 patients at stage I, 8 at stage II, 7 at stage III and 1 at stage IV. All patients achieved the Mini-Mental State test (MMS) scores of 24 or greater, and none of the patients showed middle or serious grade of dementia based on the Diagnostic and Statistical Manual of Mental Disorders-Third edition-Revised (DSM-III-R). All patients and controls underwent MMS, the Hasegawa's Dementia Screening Scale (HDS), the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the Raven's coloured progressive matrices (RCPM), The Wisconsin Card Sorting Test (WCST) and the Benton Visual Retention Test (BVRT). Auditory ERPs by standard oddball paradigm (two-choice reaction time task) were elicited (band-pass 0.1-50 Hz) from Cz electrode sites on all subjects with a random series of binaural 1,000 (standard; 80%) or 2,000 (target; 20%) Hz tones presented every 2 sec at 70 dB SPL. In RCPM, N100 peak latencies of ERP (target and standard), performance-IQ of WAIS-R (especially block design and digit symbol subtests) and in error scores of BVRT there were striking differences between the two groups (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

[Cardiac function following left ventricular aneurysm repair--comparison between patch reconstruction and direct closure methods].

Left ventricular function was compared between two groups of patients who underwent patch reconstruction or direct closure of the ventricular wall following resection of a post-infarction left ventricular aneurysm (LVA). There were 15 and 9 patients in the respective groups. Coronary artery bypass grafting was additionally performed in 8 patients (53%) in the patch reconstruction group and 5 patients (56%) in the direct closure group. The size of the patch used for patch reconstruction (including the suture line) was 57 +/- 19% of the resected area. Before and 1-2 months after surgery, equilibrium RI angiography and cardiac catheterization were performed to assess the following hemodynamic parameters: ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume index (LVEDVI), cardiac index (CI) and mean pulmonary artery pressure (m-PAP). Preoperatively, there were no differences in each parameter between the two groups. Postoperatively, there were significant improvements in the EF at rest and during exercise (p < 0.01), LVEDVI (p < 0.01) and the LVEDP (p < 0.05). However there no significant changes in CI or m-PAP following the operation. There were also no significant differences observed in the postoperative values between the two groups. However, based upon postoperative left ventriculograms, patch reconstruction was significantly superior to direct closure for reconstruction of a septal aneurysm.

Aged↗

PubMed1993

[Two cases of tension pneumothorax caused by tracheal suction during the operation of pectus excavatum].

Rehbein's method is one of the surgical procedures for pediatric pectus excavatum, which constructs thorax by lifting and fixating the sternum using metal strut inserted into bone marrow of bilateral ribs. We experienced two pediatric cases of tension pneumothorax caused by tracheal suctioning during the operation by this method. The etiology of tension pneumothorax was thought to be as follows. A small pleural hole was made during separation of ribs from surrounding tissues and a large amount of air entered into the pleural space and check valve mechanism worked at the pleural hole when the lung was collapsed on tracheal suctioning. In anesthetic management of pectus excavatum by Rehbein's method, we should always be cautious of the possible occurrence of tension pneumothorax.

Child↗

PubMed1993

[A case of intrapulmonary neurilemmoma].

A 33-year-old man was admitted to our hospital because of an abnormal shadow on chest X-ray film. Chest X-ray film and chest CT showed a round tumor in the left infrahilar area. Bronchoscopic findings revealed narrowing of left B5 and B8, with extraluminal compression. A preoperative diagnosis was not obtained and tumor resection was performed. The tumor was located in the parenchyma of left S8. Histological examination showed nuclear palisading and loosely textured spindle cells within myxomatous tissue, compatible with neurilemoma. Intrapulmonary neurilemoma is extremely rare and only 23 cases have been previously reported in Japan.

Adult↗

PubMed1993

[Mediastinal abscess due to endotracheal intubation].

A 38-year-old woman was brought to hospital in an unconscious condition due to hypoglycemic coma. At 23 years of age she was diagnosed as having insulin-dependent diabetes mellitus. She had been treated with insulin but the control of her blood sugar was inadequate. Emergency endotracheal intubation was performed and she began to breathe spontaneously. Two days later, sore throat, swelling of the neck and fever appeared. She was therefore transferred to our hospital. CT showed a continuous abscess with multiple air bubble from the pharynx to the mediastinum. Cervical incision was performed and treatment with ampicillin, cefmetazole, and clyndamicin was started. Culture of the pus revealed alpha-streptococcus. The abscess decreased in size and her blood sugar was controlled by insulin and diet. She was discharged after 11 weeks of hospitalization. At that time CT showed only emphysematous change.

Abscess↗

PubMed1993

[Clinical effects of low-dose and long-term erythromycin in diffuse panbronchiolitis with chronic respiratory failure].

We studied the effects of erythromycin (EM) in diffuse panbronchiolitis (DPB) with chronic respiratory failure. Seventeen patients with DPB or sinobronchial syndrome receiving home oxygen therapy (HOT) were treated with EM of 400-600 mg/day for twelve months. Five patients discontinued HOT, and hypoxemia was improved in five other patients. Clinical effects were evident at one month after the start of EM administration, and a stable state was achieved after six months of EM therapy. FEV1 was significantly increased in pulmonary function tests. Factors which influenced the effects of EM included the period between onset of clinical symptoms and commencement of HOT and/or between commencement of HOT and administration of EM. EM was effective for patients with obstructive, but not constrictive impairment in pulmonary function tests. These findings indicate that EM is effective for DPB even in patients with chronic respiratory failure.

Adult↗

PubMed1993

[Comparison of various methods to close the stump of the main bronchus after pneumonectomy].

In 58 patients who underwent pneumonectomy, the stumps of the main bronchus were sutured manually (by the Sweet method in 13, the Overholt method in 12, and the modified Overholt method in 8) or with machines (TA-30 + S method in 15, TA-30 + O method in 10), and the methods to close the stump were evaluated according to the outcome and postoperative endoscopic findings. Cancer was positive at the stump in 3, and rupture of the membranous portion was observed in 1 in the mechanical suture group. Bronchial fistula was observed in 2 (12%) of the 25 patients in the mechanical suture group but in none of the 33 patients in the manual suture group. The line of closure of the bronchial stump observed by endoscopy was perpendicular to the crest at the tracheal bifurcation in patients sutured by the Sweet or TA-30 + S method, angulated in a chevron shape in many of those sutured by the Overholt method and those sutured by TA-30 + O method, and parallel to the crest in part of those sutured by Overholt method and those sutured by modified Overholt method. The mucosa at the stump was uneven in many patients who showed chevron shaped closure lines. By the modified Overholt method, the wall of the main bronchus could be resected more extensively, the mucosa at the stump was smooth, and the airway lumen showed no marked deformation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗