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Biomedical subjects

K Kitaura

Publications and source records attributed to K Kitaura.

At least 37 records · Page 2Linked to original sources
PubMed1995

Comparison of hemodynamic data before and after corrective surgery for Down's syndrome and ventricular septal defect.

Left ventricular function and the extent of pulmonary vascular disease were studied in 18 children with Down's syndrome and 20 children without Down's syndrome who underwent corrective surgery for ventricular septal defect (VSD) and severe pulmonary hypertension. This study was conducted between 1985 and 1993. All patients underwent routine cardiac catheterization preoperatively and postoperatively (mean, 11.4 months after surgery). Left ventricular function was estimated using cineangiographic levograms. In both groups, the pulmonary-to-systemic arterial pressure ratio (Pp/Ps) and pulmonary vascular resistance (PVR) were significantly lower after surgery (P < 0.05). Postoperative improvement was more remarkable in the non-Down group (P < 0.05). Left ventricular end-diastolic volume (percent of normal) (LVEDV%N) was significantly lower after surgery in both groups (P < 0.01). The left ventricular stroke work-to-end-diastolic volume ratio (LVSW/EDV) was significantly higher after surgery in the non-Down group only (P < 0.01). Postoperative left ventricular ejection fraction (LVEF) was significantly lower in the Down group than in the non-Down group (P < 0.01). Some degree of irreversible pulmonary vascular disease was present after repair of VSD in patients with Down's syndrome. In the Down group, there were no significant changes in left ventricular function after surgery, despite the relief of volume overload. These results suggest that early diagnosis and surgical repair are key elements in the management of patients with Down's syndrome and VSD.

Cardiac Catheterization↗
PubMed1995

[Surgical treatment of incomplete endocardial cushion defect in adult patients].

Seven adult patients (> or = 40 years old) and six pediatric patients with incomplete endocardial cushion defect (ECD) underwent corrective surgery in our institution. Preoperative catheterization study showed that the left-to-right shunting rate and the pulmonary-to-systemic flow ratio were greater in adult patients than those in pediatric patients, but systolic pulmonary arterial pressure was not high and similar in the two groups. The degree of mitral regurgitation by left ventriculography was mild or moderate in both groups. However, in adult patients, a variety of arrhythmias were observed. Postoperatively, NYHA grades and arrhythmia improved markedly in the adult patients. Surgical correction for ECD is recommended even in adult patients before aggravation of cardiac failure and arrhythmia.

Adult↗
PubMed1995

[Renal autotransplantation for dissecting aneurysm].

Out of twenty-five patients operated on for dissecting aneurysm in our institution since January 1991, four patients had autotransplantation of the kidney. The renal autotransplantation and the segmental replacement of the descending aorta with the prosthesis were done at the same time in three of them, and segmental replacement of the distal aortic arch was followed by autotransplantation because of the postoperative acute renal failure in the other one. Postoperative renal function of simultaneously operated patients was good whereas the patient who had been treated by two-staged operation needed hemodialysis for two weeks after the autotransplantation. Postoperative scintigraphy showed fully recovered function of the autotransplanted kidneys with enlargement. CT scan showed that the false lumen of the dissecting aorta was reduced in size with increased intraluminal clot formation. Renal autotransplantation with entry closure is easy and safe technique and assures successful operative results for the dissecting aneurysm, restoring impaired renal blood flow.

Acute Kidney Injury↗
PubMed1994

Synergistic effects of phenobarbital and thiourea on proliferative lesions in the rat liver.

To evaluate the effects of phenobarbital (PB) and thiourea (TU), alone or in combination, on proliferative lesions of the liver, thyroid and lung, male F344 rats initiated with 2000 mg/kg body weight N-bis(2-hydroxypropyl) nitrosamine (DHPN) were given diet and/or drinking water containing 0% PB/TU (group 1), 1000 ppm PB (group 2), 0.1% TU (group 3) and 500 ppm PB and 0.05% TU (group 4), from weeks 2 to 20 for 19 weeks. Group 4 showed remarkable increases in the number of hepatocellular altered foci per animal, the values being superior to the averages of groups 2 and 3. The number of thyroid proliferative lesions per animal was highest in group 3 and lowest in group 2. Lung proliferative lesions were induced in all groups, but no modifying influence on their development was evident in the combined group. The present results indicate that combined administration of PB and TU exerts synergistic enhancing effects on hepatocarcinogenesis.

Animals↗
PubMed1994

Study on the carcinogenicity of tannic acid in F344 rats.

The carcinogenicity of tannic acid, a compound that is used as a food additive, a clarifying agent and a refining agent, was examined in F344 rats of both sexes. Tannic acid was dissolved in distilled water at concentrations of 0.25 and 0.5%. The doses were selected on the basis of results from a 13-wk subchronic study. Groups of 50 male and 50 female rats were given one of these solutions ad lib. as their drinking water for up to 2 yr. The mean body weights of the treated males were essentially comparable with those of the controls, whereas treated females had lower mean body weights than the control group. A variety of tumours developed in all groups, including the control group, but all the neoplasms were histologically similar to those known to occur spontaneously in this strain of rats, and no statistically significant increase in the incidence of any tumour was found in the treated groups of either sex. Thus, it is concluded that, under the conditions of the experiment, tannic acid has neither carcinogenic potential in F344 rats nor modifying effects on spontaneous tumour development.

Administration, Oral↗
PubMed1994

Spontaneous renal cell tumors in Long-Evans Cinnamon rats.

Neoplastic lesions of the kidneys in untreated Long-Evans Cinnamon (LEC) rats of 57-118 weeks old (85 males and 34 females) and male F344 rats of 64-93 weeks old (59 males) were examined histologically. The incidences of renal cell tumors in male and female LEC rats were 6/80 (8%) in weeks 57-65, 3/19 (16%) in weeks 66-75, 3/8 (38%) in weeks 76-105 and 7/12 (58%) in weeks 106-118. Of these tumors, 13 were microscopic adenomas and 7 were renal cell carcinomas. The copper content of the kidneys was about three times higher in LEC rats than in F344 rats (P < 0.001), but the iron content of the kidneys was similar in the two strains.

Animals↗
PubMed1994

Thyroid proliferative lesions induced by anti-thyroid drugs in rats are not always accompanied by sustained increases in serum TSH.

To examine changes in serum TSH and determine whether the sustained excess is necessary for the development and/or progression of thyroid tumors, male F344 rats were administered drinking water containing thiourea (TU), at 0.1 or 0.05%, or sulfadimethoxine (SM), at 0.025 or 0.0125%, for one week in Experiment I. All of the treated animals showed decreased serum levels of T3 and T4 and an increased TSH. In Experiment II, male rats were given a s.c. injection of N-bis(2-hydroxypropyl) nitrosamine (DHPN:1500 mg/kg BW) and, starting one week later, received drinking water containing the same doses of TU or SM as in Experiment I for the following 20 weeks. Thyroid follicular proliferative lesions were induced in most rats treated with TU and SM. However, these treated animals did not demonstrate any consistent alterations in serum T3, T4 and TSH levels, except for the high dose TU group. The present studies thus suggest that thyroid tumors can grow even under conditions of fluctuating serum TSH levels during the progression phase, although TSH stimulation might be an absolute requirement in the early phase of tumor development.

Animals↗
PubMed1994

[The significance of six sextant biopsy for prostate cancer].

The significance of six sextant ultrasound guided biopsies of the prostate (SS-biopsy) was evaluated in a total of 114 patients. The presence of prostate cancer was suspected (Pca) in 59 subjects through mass screening (MS) for Pca and in 47 patients in out-patient clinics (OPC). The recurrence (REC) was suspected in 3 patients diagnosed previously as Pca. All of them had elevated PSA, abnormal digital rectal examination (DRE) and/or abnormal transrectal ultrasonography (TRUS). All of these tests in 5 patients with benign prostate hypertrophy (BPH) were normal. Moreover, in 34 patients among them, oriented biopsies were performed to the area where Pca was suspected by DRE and or TRUS. Twelve Pca patients were detected in MS group (20.3%), 17 Pcas in OPC group (36.2%) and 3 Pcas in REC group (100%). No Pca patients were detected in BPH group. In 12 Pca patients with T1 or T2, only one Pca patient (8.3%) had over 3 Pca samples among the samples obtained by SS-biopsy. In 20 patients with T3 or T4, 13 patients (65%) had over 3 Pca samples. There was significant relationship between T category and Pca sample numbers among 6 samples obtained by SS-biopsy (p < 0.01). Ten of 12 Pca patients in MS group (83.3%) and 8 of 17 patients in OPC group (47.1%) had less 3 Pca samples. Pca was detected in 9 of 34 patients examined by the oriented biopsy. However al of these Pca were detected by SS-biopsy. It may be not necessary to examine Pca suspected patients by the oriented biopsy if they were examined by this SS-biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1994

[Concentrations of new quinolone agents in serum and prostate tissue].

Twenty five patients with benign prostate hypertrophy were administered ofloxacin (OFLX) simultaneously with norfloxacin (NFLX) in 6 patients, ciprofloxacin (CPFX) in 10, tosfloxacin (TFLX) in 5 and enoxacin (ENX) in 4 patients. The dose of these new quinolones was 100 mg (except 150 mg of TFLX). Their concentrations in the serum and the prostate tissue were measured by high performance liquid chromatography (HPLC). The serum concentration of OFLX was significantly higher than that of NFLX, CPFX, TFLX or ENX. The prostate tissue concentration of OFLX was significantly higher than that of CPFX or TFLX. The ratio of tissue versus serum concentration of each new quinolone agent was not significantly different. The high OFLX tissue concentration appeared to be caused by the high serum concentration.

4-Quinolones↗
PubMed1994

[Renal tubular dysfunction in open pediatric heart surgery--preventive effect of haptoglobin].

Preventive effect of haptoglobin (Hb) for renal tubular dysfunction was studied in 16 pediatric patients undergoing open heart surgery under extracorporeal circulation (ECC). The patients were divided into two groups; Hp(+) group consisting of 7 patients administered haptoglobin (100 U/kg) in priming of ECC, and Hp(-) group of 9 patients not administered haptoglobin. As parameters of renal tubular function, urinary alpha 1-microglobulin-index (U-alpha 1m.I), urinary beta 2-microglobulin-index (U-beta 2m.I), urinary N-acetyl-beta-D-glucosaminidase-index (U-NAG.I), fractional clearance of alpha 1m (Fc-alpha 1m) and beta 2m (Fc-beta 2m), as well as Free-Hb, were measured just before start of ECC and then at periodical time after ECC to the 7th day. The results obtained are as follows. (1) Maximum Free-Hb in Hp(+) group was significantly less (p < 0.05) than that in Hp(-) group. (2) Every parameter of renal tubular function were shown a peak at the end of ECC. Maximum values of U-alpha 1m.I, U-NAG.I and Fc-alpha 1m in Hp(+) group were significantly less (p < 0.05) than those in Hp(-) group. Maximum U-beta 2m.I and Fc-beta 2m in Hp(+) group were less than those in Hp(-) group, although there was no significant difference. These results indicate that administration of haptoglobin suppresses the increase of Free-Hb and is useful for prevention of renal tubular dysfunction during ECC.

Acute Kidney Injury↗
PubMed1993

A study on gamma-aminobutyric acid (GABA) and its analogues by using molecular orbital methods: on epileptogenicity of new quinolones.

Using the molecular orbital methods, we examined molecular structure, electron density distribution, electrostatic potential field and receptor structure of gamma-aminobutyric acid (GABA), and its analogues. The following findings were obtained: a comparison of the biological activity and the morphology electrostatic potentials of GABA analogues disclosed that the active site is the amino group, and the biological activity correlates closely with the electrostatic potential structure around the amino group. The active sites were compared between the receptor-binding molecules and the GABA uptake inhibitory molecules, and the results suggested that the receptor structure differed between the two groups of molecules and that the GABA A receptors had two subtypes. On these results, the epileptogenicity of new quinolones was studied using this method. These results suggested that the new quinolones blockaded the GABA receptor-binding system and that the important active site of the new quinolones for GABA receptor-binding was the the piperazyl amino group. These results suggested that the concentration of zwitterion type of the new quinolones was very important clinically.

Animals↗
PubMed1993

[Symptoms and signs of benign prostate hypertrophy (BPH)].

Clinical characteristics of BPH were investigated in the relationship among prostate volume estimated by transrectal sonography, symptoms by questionnaire, residual urine volume, and voiding force evaluated by uroflowmetry. There was no apparent relationship among them, which might be caused by the poor reproducibility of residual urine volume, the difficult enumeration of the symptoms, contamination of other diseases of which voiding disorder is correlated with aging and other unknown factors. Under such a situation, this disease should be treated as a BPH syndrome. Moreover we propose that BPH syndrome should be classified into three types; type 1: symptomatic BPH without enlarged prostate, type 2: asymptomatic BPH with enlarged prostate and type 3: symptomatic BPH with enlarged prostate.

Aged↗
PubMed1993

[A case of papillary fibroelastoma of the heart found 13 years after open mitral commissurotomy].

A patient, 68-year-old female, underwent open mitral commissurotomy (OMC) for rheumatic mitral stenosis in April, 1979. In July of 1992, during the postoperative follow-up echocardiogram showed 8 x 7 mm mitral subvalvular tumor mass and mitral restenosis. Then, mitral valve replacement was performed using prosthetic valve (Carbomedics #25 mm). The tumor was located on the top of postero-medial papillary muscle and its chordae, and histologically was diagnosed as benign papillary fibroelastoma. Based on the findings of periodic echocardiogram, the tumor doubling time was estimated to be 283 days. The postoperative course was uncomplicated and she was discharged on the 34th post operative day. Papillary fibroelastoma is a rare benign cardiac tumor. Pathological origin of this tumor is still unknown. However, Lambl's excrescence, long-term inflammatory stimulation and/or thrombi are supposed to be etiologic factors. This tumor is generally found incidentally at the time of autopsy or operation because the patients are often asymptomatic. However, because the tumor causes embolism at times, periodic examination by echocardiogram after operation preserving valves is recommended, and surgical resection is required when the diagnosis is established.

Aged↗
PubMed1993

[A case of mitral valve re-replacement with radical correction of Bland-White-Garland syndrome].

A case of an 8-year-old girl with Bland-White-Garland syndrome (BWG) who successfully underwent a second mitral valve replacement is reported. The patient had a past history of mitral valve replacement under the diagnosis of mitral regurgitation and pulmonary hypertension at one year and 3 months of age. Cardiac catheterization at 6 years and 3 months of age revealed an anomalous origin of the left coronary artery from the pulmonary artery but she was asymptomatic. One year and 7 months later, she was admitted to our institution with a sudden onset of chest pain and respiratory distress. Right heart pressure study using a Swan-Ganz catheter showed severe pulmonary hypertension and elevated mean pulmonary wedge pressure (38 mmHg). Echocardiogram revealed severe mitral stenosis and moderate regurgitation. She was diagnosed under fluoroscopy as acute left cardiac failure due to stuck valve and suspected having myocardial damage due to BWG, thus, emergency surgery was performed. Under cardiopulmonary bypass, aorto-left coronary arterial continuity was established by intrapulmonary arterial tunnel using Hamilton's technique. After resection of the prosthetic valve, of which one of two leaflets had been fixed in pannus, re-MVR was done with a St. Jude. Medical valve (25 mm). Postoperative angiogram demonstrated satisfactorily reconstructed two coronary artery systems. Postoperatively, she has been doing well without complaint for the last eighteen months.

Child↗
PubMed1992

[A ruptured thoracic aortic aneurysm with 4 cm diameter].

The size of a thoracic aortic aneurysm (TAA) is an important factor of the operative indication. We experienced a ruptured TAA the diameter of which was only 4 cm. A 71 years old man was admitted due to the severe back pain under the shocked condition. We diagnosed him a ruptured TAA by CT scan. Because he had no progressive anemia and the hemodynamics was very stable, we followed him conservatively. Two months later, the operation was performed. We resected the aneurysm and inserted an aortic prosthetic graft. From the operative findings, the aneurysm was certified as a true aneurysm, and the maximal diameter was only 4 cm. First choice for the treatment of ruptured TAA is the emergent operation. But when the hemodynamics is extremely stable and the anemia does not progress at all, a conservative therapy can be selected. Even if the aneurysm is very small, the control of hypertension is quite important.

Aged↗
PubMed1991

[Subchronic oral toxicity study of cyanoguanidine in F344 rats].

A 13-week subchronic oral toxicity study of cyanoguanidine was performed in male and female F344 rats by feeding of CRF1 powder diets containing 0, 1.25, 2.5, 5 and 10% cyanoguanidine to determine appropriate dose levels for a subsequent 2-year carcinogenicity study. The rats were randomly allocated to 5 groups, each consisting of 10 males and 10 females. No animals died during the administration period. Inhibition of body weight gain was more marked in both sexes of the 10% group and in females of the 5% group as compared with the control group. Mean food intake in males of the groups treated with 5% or 10% and in females of the 10% group was significantly higher than that in the control group. Serum biochemical investigation revealed a higher level of serum BUN in both sexes of the 10% group. On histopathological examination, toxic changes characterized by the occurrence of intranuclear eosinophilic inclusion bodies in the proximal tubular epithelium of the kidney were observed in both sexes of the 10% group. Similar inclusion bodies were also seen in 2 out of 10 males of the 5% group. From these results, it was concluded that a level of 10% of cyanoguanidine in the diet is unequivocally toxic. A dose level, 5% cyanoguanidine, in the diet might be appropriate as a high dose for a carcinogenicity study.

Administration, Oral↗
PubMed1990

[Prognostic factor for prostate cancer. Gunma Urological Oncology Study Group].

The study of prognostic factors in patients with prostate cancer (Pca) may be of value in understanding the natural history of the disease and may also assist in planning and analyzing the results of clinical trials. Moreover some information through this study would be beneficial to assessing the prognosis and decision of better therapy form of individual patients. The significance of items studied was evaluated from the two view points, survival rate and Pca death rate. Stage, pathological differentiation and acid phosphatase were significantly related to them, in the category grade depending manner. Past history and complication, and age were also significantly related to them but higher category grade as a survival factor showed lower Pca death rates. ESR, gait disturbance and hematuria were related to only survival rate. Any significant relationship was not observed in serum testosterone, voiding disturbance and cancer-pain. Prognostic factors should be clinically used through the well understanding of each characteristics. This paper also showed that statistical significance not always provide a wide difference between categories compared.

Age Factors↗