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Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 1,027 records · Page 57Linked to original sources
PubMed1990

Repeat renal biopsy in children with IgA nephropathy.

Serial renal biopsy findings in 61 children with IgA nephropathy were correlated with their clinical course. At the time of the second biopsy, 23 patients showed clinical remission defined as complete disappearance of proteinuria and hematuria with normal renal function while 38 had persistent urinary abnormalities with normal renal function at the second biopsy. There were no differences between the two groups with regard to initial clinical findings and pathologic findings of the initial renal biopsy. The second biopsy of patients with clinical remission showed improvement of the glomerular changes on light microscopy, disappearance or diminution of IgA deposits in the mesangium and decrease of electron-dense deposits, whereas the second biopsy of patients with persistent urinary abnormalities showed progression of glomerular changes on light microscopy, persistence of mesangial IgA deposits and persistence of electron-dense deposits. Our study results show the importance of repeat renal biopsy in children with IgA nephropathy with persistent urinary abnormalities, as a progression of glomerular changes is common in these patients. These observations suggest that the deposition of IgA in the mesangium may be responsible for the glomerular damage in children with IgA nephropathy.

Adolescent↗
PubMed1990

[A case of orbital hemangiopericytoma].

A 38-year old woman presented with severe proptosis in the left eye which had been developing for more than ten years. CT scan revealed a large mass in the left orbit, therefore lateral orbitotomy was performed. The histopathology of this tumor consisted of ovoid to spindle-shaped cells tumor around a sinusoidal vascular component forming staghorn channels. This tumor was diagnosed as a hemangiopericytoma. The prognosis of orbital hemangiopericytoma including clinicopathological aspects are discussed with reference to recent reports.

Adult↗
PubMed1990

[Pleuropneumonectomy with thymectomy for invasive thymoma with pleural disseminations--a case report].

A case of invasive thymoma with pleural disseminations, treated with pleuropneumonectomy and thymectomy , is presented. A 30-year-old woman was admitted with abnormal shadows in left lung field and mediastinum. On chest CT examination, the tumor shadows were located anterior mediastinum and left chest wall. Thymoma with pleural disseminations was the most likely consideration by the needle biopsy specimen of the tumor under left chest wall. Preoperative radiotherapy for anterior mediastinum mass was effective. Pleuropneumonectomy and thymectomy combined with partial resections of intercostal muscles and diaphragm were performed. Histologically, the tumor was arranged in lobular structure, composed of epithelial cells, with poorly infiltration of lymphocytes, and invaded into intercostal muscles or lung. Postoperative radiotherapy for mediastinum and left chest wall was added. Tumors may be removed completely by pan-pleuropneumonectomy and thymectomy for invasive thymoma with pleural disseminations.

Adult↗
PubMed1990

[A useful combination chemotherapy of cisplatin and etoposide in mediastinal yolk sac tumor].

A 28-year-old male was referred to our hospital because of chest pain and dry cough. Chest x-ray film revealed a tumor mass in the anterior mediastinum indicating invasion into the chest wall and upper lobe of right lung. No tumor was found in the testis. Serum level of alpha-fetoprotein (AFP) was 6,400 ng/ml. Percutaneous biopsy of the tumor suggested yolk sac tumor. The patient was treated with a combination chemotherapy schedule including 30 mg of cisplatin (CDDP) i.v. on Days 1, 2, 3, 4, and 5 and 150 mg of etoposide on Days 1, 2, and 3 as one course therapy. Two courses were employed. Partial response was achieved followed by successful resection of the tumor. This case indicated that a combination chemotherapy CDDP and etoposide combined with surgery could play an active role increasing long-term survival rates in mediastinal yolk sac tumors.

Adult↗
PubMed1990

[Long-term follow-up results in nonoperated patients with intrahepatic and predominant intrahepatic type of hepatolithiasis].

In order to clarify therapeutic principles of hepatolithiasis associated with a variety of pathological conditions, we studied follow-up results in a term of 5 years after diagnosis in 29 nonoperated patients with intrahepatic gallstones. The patients including 14 males and 15 females underwent direct cholangiography for making diagnosis of the disease consisting of the intrahepatic type (I) and the predominant intrahepatic (IE). Out of the patients, 21 had good results in the follow-up and no one died from the disease or cholangiocarcinoma incidentally occurred. The follow-up results were closely related with the distribution and the location of gallstones in the liver and the grade of severity in clinical symptoms at the diagnosis. The unilateral lober type of the stone distribution had better follow-up results than the bilateral (P less than 0.01), and the peripheral intrahepatic bile duct type of the stone location did better follow-up results than the major (P less than 0.01). The pathological state of mild clinical symptoms showed better follow-up results than that of severe ones (P less than 0.05). The removal of coexisted extrahepatic bile duct stones by endoscopic papillotomy was effective for improving clinical symptoms. The conservative treatment in hepatolithiasis with the type I or IE was generally good in the follow-up results. The follow-up results were various, depending on the pathological conditions at the diagnosis. Accordingly, the treatment of hepatolithiasis must be selected in consideration of pathological conditions.

Adolescent↗
PubMed1990

[A case of thoracic neurilemoma with neurilemomas of the upper limb and sacrum].

A 64-year-old male was admitted in February 24, 1988 because of an abnormal shadow on chest X-ray. The tumor in the thoracic wall was removed at the thoracotomy and histology showed neurilemoma. Aspiration biopsy of tumors on the left upper limb and sacrum revealed the typical histopathologic appearance of neurilemomas. The possibility of malignant transformation and sequential appearance of tumors in patients with a neurilemoma indicates that complete resection and thorough follow-up examination are important.

Humans↗
PubMed1990

[Megaloblastic anemia and platelet function--a qualitative platelet defect in pernicious anemia].

In order to know the entities of platelet defect in pernicious anemia, we investigated platelet functions in ten cases with pernicious anemia. Three of the cases had total gastrectomy. Five cases showed thrombocytopenia and four cases revealed prolongation of Ivy bleeding time. Decreased adhesiveness was observed in three cases. Various abnormalities in platelet aggregation were observed. However, almost all of the cases showed remarkable improvement of decreased platelet functions after the therapy of Vitamin B12 injection. The results of adenine nucleotides in platelets and the release of them following collagen or epinephrine aggregation were analysed in comparison with normal platelets. The ADP was definitely decreased and the ATP/ADP ratio was increased. In addition, the release of ATP and ADP at collagen or epinephrine induced aggregation was markedly decreased, and after the therapy of Vitamin B12, the decrease of adenine nucleotide release remarkably increased. In summary, the acquired defects of platelet function in pernicious anemia are regarded as a secondary storage pool disease, and its defects improve after Vitamin B12 therapy.

Adult↗
PubMed1990

[Estimation of the reticuloendothelial function by positron emission computed tomography (PET) study in chronic liver disease].

We have developed a new liver scanning agent (Ga-68 human serum albumin microspheres) in a convenient kit for use in positron emission computed tomography (PET). In this study, this scanning agent was evaluated for clinical usefulness as a function test for the reticuloendothelial system. A dose of 5 micrograms/kg (1-2 mCi) of Ga-68 microspheres was injected intravenously to 25 patients, 11 with chronic hepatitis and 14 with liver cirrhosis, and 5 normal volunteers for PET imaging of the liver and spleen using HEADTONE-III (SET 120W). The volumes of the liver and the spleen and the uptakes of Ga-68 microspheres were calculated as an index of the reticuloendothelial system function. In liver cirrhosis the liver volume estimated by PET was decreased and the spleen volume was increased. Both the liver uptake rate and differential absorption ratio (DAR) of the radioactivity were decreased corresponding with the degree of chronic liver disease. The spleen uptake rate was increased with progression of chronic liver diseases, but there was no difference in DAR between normal volunteers and patients with chronic liver disease. it was concluded that PET using Ga-68 microspheres is useful in the evaluation of the function of the reticuloendothelial system.

Chronic Disease↗
PubMed1990

[A case of mediastinal yolk sac tumor successfully treated with chemotherapy and surgery].

A 28-year-old man was admitted due to increasing respiratory symptoms. X-ray examination of the chest showed a tumor mass in the anterior mediastinum with possible invasion into the chest wall and upper lobe of right lung. No tumor was found in the testis. Serum alpha-fetoprotein (AFP) concentration was 6400 ng/ml. Serum levels of CEA and HCG were within normal limits. Percutaneous biopsy of the tumor strongly suggested yolk sac tumor with an evidence of AFP by an immunoenzyme labelling technique. The serum AFP rapidly decreased after two courses of combination chemotherapy. En bloc resection of the tumor was successfully performed and third chemotherapy was added. Mediastinal yolk sac tumors should be treated with combination chemotherapy and surgical resection.

Adult↗
PubMed1990

[A preliminary study on the morphological changes of the microvasculature following the peripheral nerve autografting].

The microvasculature of peripheral nerve following autografting was studied by scanning electron microscopy. The newly-formed capillaries was also examined by transmission electron microscopy. Capillaries of a fascicle were divided into an extrafascicular vascular plexus and an intrafascicular capillary bed; the former capillaries formed networks, while the latter capillaries ran longitudinally and formed slightly spiral curve. Normal intrafascicular capillaries had tight junctions, a continuous basement membrane and pericytes. On the suture line, capillaries of the graft and those of the host were connected by newly developed sinusoidal capillaries, which were formed at the extrafacicular region earlier than at the intrafascicular region. Newly developed sinusoidal capillaries were transformed into glomerulus-like capillaries and formed fine networks. These networks exhibited a normal capillary architecture after reconstruction. The endothelium of newly-formed capillaries showed a discontinuous basement membrane at the early stage of regeneration. An intrafascicular capillary bed was present in the middle part of the graft.

Animals↗
PubMed1990

[Acute renal failure in patients with hematologic neoplasms].

The retrospective study of acute renal failure (ARF) in patients with hematologic neoplasms was carried out. ARF occurred in 32 (6.1%) of 526 patients with hematologic neoplasms. Twenty-one (66%) patients recovered from ARF, but only 7 (22%) survived and were discharged from the hospital and 25 (78%) died of ARF or other complications. In 17 patients with leukemia or malignant histiocytosis, sepsis and/or disseminated intravascular coagulation were the most common causes of ARF, and all 17 patients died. In 11 patients with multiple myeloma, ARF was always attributable to the underlying disease, and the clinical course improved with the initiation of blood purification therapy (hemodialysis, plasma exchange) and chemotherapy. Five patients in blast crisis of chronic myelogenous leukemia or non-Hodgkin's lymphoma developed ARF as a result of tumor lysis syndrome. In this group, renal function improved with hemodialysis but only 2 patients survived. Patients with oliguria had worse outcomes than those without oliguria. Survival appeared to depend not on renal function but on the underlying disease, the cause of ARF, and other complications. These findings suggest that, in patients with hematologic neoplasms complicated by ARF, early initiation of blood purification therapy will improve the prognosis.

Acute Kidney Injury↗
PubMed1990

[Anesthetic management of patients with cardiomyopathies].

Anesthetic management of patients with cardiomyopathy was studied. In the past 8 years, we experienced 24 surgical procedures for 16 patients complicated with cardiomyopathy of whom 6 cases with hypertrophic type (HCM) and 10 cases with dilated type (DCM). In HCM there was no correlation between the incidence of intraoperative complication and preoperative evaluation by New York Heart Association. In HCM cases who revealed atrial fibrillation, conduction disturbance on ECG and hypokinesis on echocardiogram resulted in high incidence of cardiac complication during anesthesia. Induction of anesthesia is extremely risky if the anesthesiologist is not aware of the presence of cardiomyopathies. In DCM, preoperative episode of heart failure, arrhythmias and conduction disturbance on ECG were considered as anesthetic risk factors. Both in HCM and DCM, there were no statistical significance in complication between general anesthesia and epidural anesthesia. The authors recommend epidural technique as a method of choice for HCM patient.

Adult↗
PubMed1989

Dimethylated arsenics induce DNA strand breaks in lung via the production of active oxygen in mice.

In order to study the genotoxicity of arsenics, we focused our attention on dimethylarsinic acid (DMAA) which was a main metabolite of inorganic arsenics in mammals. ICR mice were orally administered DMAA-Na (1500mg/kg). DNA single-strand breaks occurred specifically in lung at 12h after administration. An in vitro experiment indicated that the breaks were not caused directly by DMAA but by dimethylarsine, a further metabolite of DMAA. Furthermore, the dimethylarsine-induced breaks were diminished by the addition of SOD and catalase, suggesting that active oxygen produced by dimethylarsine was involved in the induction of DNA damage.

Animals↗
PubMed1989

Thiobarbituric acid-reactive substance formation of rat kidney brush border membrane vesicles induced by ferric nitrilotriacetate.

An iron chelate, ferric nitrilotriacetate (Fe3+-NTA), is nephrotoxic and also carcinogenic to the kidney in experimental animals. Iron-promoted lipid peroxidation in the proximal tubules is thought to be responsible for the pathologic process. In the present study, iron-promoted lipid peroxidation, with thiobarbituric acid (TBA) formation as an indication, in the tubular surface was simulated in vitro using rat kidney brush border membrane vesicles and the results were compared with those using linoleate micelles and rat liver microsomal lipid liposomes. Addition of ascorbate, cysteine, or dithiothreitol to the Fe3+-NTA solution resulted in consumption of dissolved oxygen and promoted the lipid peroxidation in the micelles and in the liposomes. In contrast, addition of glutathione to the Fe3+-NTA solution caused only sluggish oxygen consumption and far less peroxidation in these lipid systems. When the brush border membrane vesicles were used for the peroxidation substrate, Fe3+-NTA and glutathione could promote TBA formation at a rate comparable to that elicited by Fe3+-NTA with cysteine or dithiothreitol. Acivicin, a gamma-glutamyl transpeptidase inhibitor, suppressed the peroxidation of the brush border membrane vesicles promoted by Fe3+-NTA and glutathione. These results suggest the following mechanism of proximal tubular cell lipid peroxidation promoted by Fe-NTA: Fe3+-NTA filtered through glomeruli is rapidly reduced by cysteine and Fe2+-NTA starts lipid peroxidation at the site, leading to proximal tubular necrosis. Cysteine is amply supplied by the decomposition of glutathione within the lumen by the action of gamma-glutamyl transpeptidase and dipeptidase situated at the proximal tubular brush border membrane.

Acetates↗
PubMed1989

A stimulatory effect of recombinant murine interleukin-7 (IL-7) on B-cell colony formation and an inhibitory effect of IL-1 alpha.

Using a clonal culture system, we investigated the lymphohematopoietic effects of recombinant interleukin-7 (IL-7) obtained from conditioned media of transfected COS 1 cells. IL-7 alone acted on murine bone marrow cells and supported the formation of B-cell colonies. These colony cells were positive for B220, and some of them were also found to have either IgM or Thy-1. B220+, IgM- cells, but not B220- cells sorted from fresh bone marrow cells were able to form B cell colonies in the presence of IL-7. Thus, IL-7 supported the differentiation of B220+, IgM- cells to B220+, IgM+ cells. B220+, IgM+ cells did not proliferate in the presence of IL-7. IL-7 did not affect the myeloid colony formation supported by IL-3, IL-5, IL-6, granulocyte macrophage colony stimulating factor (GM-CSF), and G-CSF. On the other hand, lymphocyte colony formation was not affected by IL-2, IL-3, IL-4, IL-5, IL-6, GM-CSF, or G-CSF. Interestingly, IL-1 alpha inhibited IL-7-induced B cell colony formation in a dose-dependent manner, while the same concentration of IL-1 alpha enhanced the myeloid colony formation by IL-3. This reciprocal effect of IL-1 alpha may act on hematopoietic progenitor cells without accessory cells. These data show that IL-7 is a B cell growth factor and that IL-1 alpha may play an important role in differentiation of myeloid and lymphoid lineages.

Animals↗