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Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 541 records · Page 30Linked to original sources
PubMed1997

Serial magnetic resonance imaging findings of Rasmussen's encephalitis--case report.

A 12-year-old boy presented with Rasmussen's encephalitis. Serial magnetic resonance (MR) imaging one year after the onset of seizure showed no abnormality. T2-weighted imaging detected a high intensity lesion in the left frontal cortex when the frequency of seizures increased 11 months later. MR imaging showed the lesion rapidly spread into the white matter, then gradually regressed after biopsy and immunoglobulin therapy, and mild focal atrophy of the left frontal lobe in spite of recurrence of seizures 3 months after the therapy. Histological examination of the biopsy sample showed the characteristic findings of Rasmussen's encephalitis. Five months after the biopsy, another new high intensity lesion was detected next to the previous one, although his seizures were well controlled at that time. Although the extent of the high intensity lesion did not correlate with the frequency of seizures, such sequential changes in MR imaging appearance seemed to reflect the course of this disease.

Anti-Inflammatory Agents↗
PubMed1997

Methicillin-resistant Staphylococcus aureus (MRSA) isolation from pharyngeal swab cultures of Japanese elderly at admission to a geriatric hospital.

The isolation rate of the methicillin-resistant Staphylococcus aureus(MRSA) from pharyngeal swab cultures in Japanese elderly was studied at admission to a geriatric hospital. The subjects were 233 consecutive patients admitted to Kitakyushu Tsuyazaki Hospital from April 1994 to March 1996. The isolation rate of MRSA was 3.0% in the patients admitted from their own homes, 9.7% in those transferred from nursing homes and 14.0% in those transferred from other hospitals. The patients from their own homes were younger than those from nursing homes, the latter being older than those transferring from other hospitals. The patients from their own homes had better activities of daily living(ADL), higher levels of hemoglobin and serum albumin than those from nursing homes or other hospitals. The white blood cell counts, and the proportion of patients with positive c-reactive protein or with fever did not differ among the three groups. Multiple logistic regression analysis revealed that fever and ADL disability were independent risk factors for the isolation of MRSA, and hypoalbuminemia was a risk factor for MRSA isolation in the model using serum albumin instead of ADL score. These results suggest that the lower isolation rate MRSA among patients from their own homes may be partly due to better ADL and nutritional status compared with those from nursing homes or other hospitals.

Aged↗
PubMed1997

Citrate uptake by isolated rat renal brush border membrane vesicles in cadmium-intoxicated rats.

Epidemiological Studies have reported that the formation of renal stones is often observed in workers exposed to cadmium (Cd). Citrate is known to be a protective factor against renal stone formation. We previously reported that direct exposure to high-level cadmium impaired the citrate uptake by the brush border membrane vesicles (BBMV), which may mean that the formation of renal stones from exposure to Cd could be prevented. In the present study, to clarify the mechanism of Cd-induced renal stone formation, the characteristics of BBMV-induced citrate uptake were determined in Cd-intoxicated rats. Cd intoxication was induced by daily subcutaneous injections of CdCl2 at a dose of 2 mg Cd/kg body wt per day for 17 to 20 days. The BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration technique. The citrate uptake per mg protein was not significantly different between the two groups. The volume of BBMV was significantly reduced (50%) in Cd-intoxicated rats compared with that of control rats. Percentages of the equilibrium value were also significantly inhibited in Cd-intoxicated rats.

Animals↗
PubMed1997

Direct effect of inorganic mercury on citrate uptake by isolated rat renal brush border membrane vesicles.

Occupational exposure to mercury has long been associated with renal proximal injury and an increased incidence of proteinuria, as has such exposure to cadmium. Renal citrate excretion is very important with respect to acid-base balance since the metabolism of citrate generates three bicarbonate ions. In this study, we exposed isolated rat renal brush border membrane vesicles (BBMV) to mercury (Hg2+) and examined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration method. The preincubation of BBMV with 0.5 and 2 mM HgCl2 for 1 min significantly inhibited citrate uptake compared with that of BBMV without Hg preincubation. The analysis of the time course of citrate uptake during a 30-min preincubation of BBMV with 0.1 mM Hg2+ also revealed a significant reduction in the uptake compared with that of the control BBMV without preincubation. These findings indicate that the preincubation of BBMV with mercury results in a time- and concentration-dependent inhibition of citrate uptake.

Animals↗
PubMed1997

[Clinical features of Sjögren syndrome].

Between 1985 and 1995, 134 patients presented to our clinic with complaints of either dry mouth, decreased salivary flow or salivary gland swelling of unknown origin. These patients were diagnosed retrospectively based on the criteria established by the Sjögren's disease research committee (1977), and 30 patients were definitively diagnosed with Sjögren's disease while 23 were considered suspect. The gender distribution of these 30 patients was 25 female (83%) and 5 male (17%). The average patient age was 55.8 years for females and 42.6 years for males. Of 30 patients, 10 (33.3%) had only sicca syndrome and the other 20 (66.7%) had various complications such as collagen diseases, autoimmune diseases, and malignant lymphoid infiltration. Subjects included 14 cases of rheumatoid arthritis (RA), 1 case of systemic lupus erythematosus (SLE), 1 case of RA with periarteritis nodosa (PN), 1 case of progressive systemic sclerosis (PSS) with SLE, 1 case of PSS with Hashimoto disease, 1 case of malignant lymphoma and 1 case of RA with Waldenström's macroglobulinemia. Positive blood tests showed a relatively high incidence of elevated erythrocyte sedimentation ratios (ESR) (75%), elevated IgG levels (69.2%), positive anti-nuclear antibody (52.3%), positive anti SS A antibody (75%) and positive anti-SS B antibody (50%).

Adolescent↗
PubMed1997

[Histological classification of renal cell carcinoma--problems in JUA classification].

BACKGROUND: Although renal cell carcinoma (RCC) is often heterogeneous, the histological classification of RCC in Japanese Urological Association (JUA) is designed to select only the dominant histological components. We evaluated whether this system could provide an adequate information concerning the prognosis of the patients. METHODS: Histological slides of 130 cases with RCC were microscopically evaluated. We classified these cases according to the JUA classification, and also checked the presence or absence of each histological components (3 cell types and 5 histological architectures) regardless of whether or not they were dominant. Univariate and multivariate analysis were then performed to determine the histological components which have prognostic impact on patient survival. RESULTS: Multivariate analysis demonstrated that only spinde/pleomorphic cells and solid architecture were the significant prognostic parameters. The presence of these histological components was not correctly shown in the JUA classification. CONCLUSION: The histological classification of RCC in JUA did not provide enough information about the presence of the important prognostic parameters. This system should be modified to describe all the histological components regardless of whether they are dominant or not.

Adult↗
PubMed1997

[Experimental and clinical studies for laser irradiation to the prostate].

BACKGROUND: The object of the study is to observe the influence of laser on the prostate tissue and to evaluate the efficiency as well as safety. METHODS: Ten canine prostates were irradiated by Nd:YAG laser with a lateral firing fiber. The lasing was carried out either spot or running irradiation on the free beam method. Laser energy was applied for 30, 40 and 60 seconds at 50 watts power output. On the basis of the animal experiments, clinical application was performed in patients with BPH. RESULTS: Immediately after the irradiation, the prostate became swollen by the edema. But the irradiated tissue became necrotic and sloughed resulting in a big cavity of the prostatic urethra by two weeks. The higher the energy density with spot irradiation, the larger the tissue effect as well as the risks. Therefore, it would be important to combine spot with running irradiation for optimal energy density. Clinically, subjective and objective improvements were noted significantly after treatment. CONCLUSION: Thus, the endoscopical laser prostatic therapy proved to be useful and safe from the present fundamental and clinical investigations.

Aged↗
PubMed1997

[Impact of androgen deprivation prior to radical prostatectomy for T1, T2 prostate cancer on the likelihood of curative surgery].

BACKGROUND: Extracapsular extension is commonly seen in patients undergoing radical prostatectomy for localized prostate cancer due to understaging of disease. One possible approach to reduce the likelihood of extracapsular disease is androgen deprivation prior to radical prostatectomy, neoadjuvant therapy. However, adequate application is not clear. We analyzed the outcome of neoadjuvant therapy and radical prostatectomy in an attempt to expand our understanding on indications of neoadjuvant therapy. METHODS: Forty-six selected patients with clinical T1 or T2 prostate cancer were retrospectively reviewed. Twenty-two patients underwent neoadjuvant therapy (group N) that mainly consists of LH-RH agonist. The duration of neoadjuvant therapy, varied from 1 to 12 months with the mean being 4 months. Twenty-four underwent radical prostatectomy alone (group S). RESULTS: In the group N and group S, 59% and 33% had either organ confined disease (OCD) or specimen confined disease (SCD) respectively. When the patients had OCD or SCD, they were defined as surgically cured patients. In the patients with clinical stage T1b, T1c, and T2 disease, likelihood of surgical cure were 100%, 50%, 46.7% in group N, 100%, 20%, 11%, in group S respectively. In the patients with initial serum PSA less than 10 ng/ml and more than 10.1 ng/ml, likelihood of surgical cure were 83.3% and 50% in group N, 63.6% and 15.4% in group S, respectively. Likelihood of surgical cure was higher in the patients with well differentiated carcinoma both in group N and group S. All the patients with serum PSA less than 0.1 ng/ml after neoadjuvant therapy had OCD. CONCLUSION: Neoadjuvent therapy could be beneficial either in the patients with moderately or in the poorly differentiated adenocarcinoma of prostate especially in the group with initial serum PSA more than 10.1 ng/ml. However, in patients both with well differentiated adenocarcinoma and the initial serum PSA less than 10 ng/ml, no evidence of beneficial effect on the likelihood of OCD or SCD was observed. PSA after neoadjuvant therapy could be useful predictor for the pathological outcome.

Aged↗
PubMed1997

Morphological and biochemical analyses on fibroblasts and self-produced collagens in a novel three-dimensional culture.

The addition of L-ascorbic acid 2-phosphate (Asc 2-P), which is active and stable under a conventional culture condition, could render dermal fibroblasts to the organization of a dermis-like structure on a plastic dish without any prior treatment. The cell layer was composed of multilayered fibroblasts surrounded by dense extracellular matrices. Confocal microscopic examination disclosed that the fibroblasts in the upper layer were spindle-shaped and those in the lower layer were polygonal. Electron microscopic examination revealed the accumulation of mature collagen fibrils in the intercellular space. These morphological observations suggest that the cell layer may resemble the dermis-like structure. Biochemical analyses revealed that the hydroxyproline content of the cell layer increased in a time-dependent manner, while the monolayer culture system without. Asc 2-P yielded no measurable amount of hydroxyproline. On sodium dodecylsulphate-polyacrylamide gel electrophoresis, neutral insoluble collagens extracted from the cell layer showed the identical electrophoretic pattern to those from the human dermis. In addition, these bands were completely digested by bacterial collagenase. This novel culture system could provide a simple tool with which to investigate the collagen metabolism by fibroblasts under more physiological conditions.

Adolescent↗
PubMed1997

[Left atrial isolation for chronic atrial fibrillation associated with valvular disease and coronary artery disease in an 82-year-old man].

An 82-year-old man suffering from chronic atrial fibrillation associated with valvular and coronary artery diseases was admitted to our hospital. Preoperative examination revealed that mitral and aortic valve replacement with tricuspid annuloplasty and coronary artery bypass were required, in addition to surgery for chronic atrial fibrillation. In order to shorten the aortic cross-clamp time and operative time, we performed left atrial isolation, which is a simpler procedure than maze procedure and the left sided maze procedure, because it requires incision of the posterior left atrium only. Since aortic stenosis was severe and the aortic annulus was small, we used a St. Jude Medical Hemodynamic Plus valve as the aortic valve prosthesis, which spares the surgical stress of the aortic annulus. Careful investigation of the patient disorder and selection of optimal surgical procedure makes possible an extended operation of complicated valvular disease even in a high elderly patient over 80 years old.

Age Factors↗
PubMed1997

[Primary malignant lymphoma of the bladder: a case report].

An 86-year-old woman was admitted to our hospital with genitourinary bleeding. Abdominal computerized tomography demonstrated a low density mass on the posterior wall of the bladder. Cystoscopy revealed a nonpapillary bladder tumor. A transurethral cold cup biopsy showed lymphocytic infiltration with no malignant cells. She died 2 years after the initial presentation and autopsy revealed malignant lymphoma, diffuse B cell type, small cell type. A cold cup biopsy of the bladder mucosa sometimes fails to detect primary malignant lymphoma of the bladder because of its submucosal location.

Adenocarcinoma↗
PubMed1997

[Fatal pulmonary embolism during knee surgery under epidural anesthesia].

A 36 year old male patient suddenly died of pulmonary embolism during the second application of a pneumatic tourniquet undergoing tibial fracture repair. Pulmonary artery angiography using Swan-Ganz catheter demonstrated that the left and right pulmonary arteries were occluded except the partial left upper lobe. PaO2 was below 7 mmHg, and cardiopulmonary resuscitation was not possible. Autopsy showed massive emboli completely blocking the both pulmonary arteries.

Adult↗
PubMed1997

Huge aneurysm of the sinus of Valsalva following infective endocarditis in Behçet's disease.

A huge aneurysm of the sinus of Valsalva with conduction disturbance as a consequence of infective endocarditis in Behçet's disease is reported. The aneurysm extended not only into the ventricular septum but also to the right atrium and ventricle, with a complicated cavity formation. We speculate that complete atrioventricular block occurred due to an enlargement of the aneurysm into the ventricular septum, leading to a direct conduction system injury. Preoperative echocardiography and aortography were insufficient to recognize the extent of the lesion; subsequent operative examination revealed the true size. At operation, it is important to understand the lesion dimensions fully in order that appropriate surgical procedures be performed.

Aortic Aneurysm↗
PubMed1997

[Clinical studies on renal pelvic and ureteral carcinoma].

We reviewed 40 patients with renal pelvic and/or ureteral transitional cell carcinomas, consisting of 24 males and 16 females with a mean age of 65 years. The histopathological stage of surgically removed specimen was pTa in 6 patients, pT1 in 7, pT2 in 5, pT3 in 11 and pT4 in 6. Three patients with Tis and 2 with T3 did not undergo surgery. Of 35 patients pathologically examined, lymphatic and venous invasions were detected in 22 (63%) and 16 (46%), respectively, and were associated with pathological stage and grade. Overall the 5-year actuarial survival rate was 57.1%. Tumor staging and vascular invasion had a prognostic significance on the treatment outcome, but not metachronous or synchronous bladder cancer, identified in 55% of the patients. Adjuvant chemotherapy appeared to improve the survival of the patients with tumors pT2 or higher, grade 3 or vascular invasion without metastases.

Aged↗
PubMed1997

Single lung transplantation for canine pulmonary hypertension.

BACKGROUND: In spite of recent reports of the clinical application of single lung transplantation for pulmonary hypertension, there is little underlying experimental data because of the lack of a reliable animal pulmonary hypertensive transplant model. We have established a pulmonary hypertensive model in beagles with dehydromonocrotaline and have been able to measure cardiopulmonary hemodynamics accurately and use circulatory assists during procedures. The purpose of this study was to determine whether single lung transplantation could be performed after the protocol of clinical procedure. METHODS AND RESULTS: In six control dogs, allografting was successfully completed without cardiopulmonary bypass. Because one pulmonary hypertensive recipient dog died of right ventricular failure during the procedure without cardiopulmonary bypass, we used bypass for allografting in five pulmonary hypertensive dogs. Cardiopulmonary bypass lowered pulmonary artery pressure, allowing pulmonary arterial clamping and avoiding right ventricular overload. All pulmonary hypertensive dogs undergoing bypass were successfully weaned from bypass, indicating a good hemodynamic response to transplantation. In pulmonary hypertensive dogs, transplantation resulted in significant decreases in systolic pulmonary artery pressure and pulmonary vascular resistance, and a significant increase in blood flow to the graft lung, whereas in controls the results were the reverse. CONCLUSIONS: Thus we were able to show that hemodynamics improved after single lung transplantation with cardiopulmonary bypass in a new pulmonary hypertensive animal model. These relatively larger animals are valuable for further studies of single, double, bilateral, and heart-lung transplantation for pulmonary hypertension.

Animals↗