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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 307 records · Page 17Linked to original sources
PubMed1992

Frequent rearrangements of retinoic acid receptor alpha gene and myl gene, and rare mutations of RAS and FMS genes in acute promyelocytic leukemia.

To investigate leukemogenesis of acute promyelocytic leukemia (APL), we studied the involvements of retinoic acid receptor alpha (RAR alpha) and myl genes, and also the frequency of N-RAS, K-RAS, H-RAS, and FMS point mutations in sixteen patients with APL. By Southern blot analysis, the rearrangements of RAR alpha gene were detected in 13 patients (81.2%), and myl gene in 14 (87.5%). Either RAR alpha or myl gene rearrangements were found in all patients including one with normal karyotype. Breakpoints of both genes were clustered. By direct sequencing, no point mutations were found at codons 12, 13, and 61 of N-, K-, and H-RAS genes, and at codons 301 and 969 of FMS gene. These data indicate that myl-RAR alpha translocation occurs frequently in APL, whereas RAS and FMS mutations are rare in APL. It may be suggested that leukemogenesis of APL is different from other subtypes of acute myelogenous leukemia, and multistep leukemogenesis may not be a prevalent feature in APL.

Adolescent↗
PubMed1992

Percutaneous fenestration of dissecting intima with a transseptal needle. A new therapeutic technique for visceral ischemia complicating acute aortic dissection.

Noncardiac visceral ischemia is a major complication with acute aortic dissection and is caused by obstruction of the major visceral arteries by dissecting intima. Two patients with this condition underwent emergency percutaneous fenestration of dissecting intima, and the blood flow to the lower extremity and kidney was restored. A transseptal needle and peripheral angioplasty balloon catheter were used for fenestration. There were no associated complications in either patient. One patient was treated medically and another had ascending aortic replacement surgery the day after percutaneous fenestration. Clinical follow-up of 10 and 5 months, respectively, revealed good clinical outcomes. Percutaneous fenestration should be considered the treatment of choice for visceral ischemia due to acute aortic dissection.

Aortic Dissection↗
PubMed1992

A new therapeutic method for chronic subdural hematoma in adults: replacement of the hematoma with oxygen via percutaneous subdural tapping.

Seeking radical removal of chronic subdural hematoma using a simple and less invasive procedure, the author has devised a new method--replacement of the hematoma with oxygen via percutaneous subdural tapping. In this study, 40 patients were treated with this procedure. All patients made a full recovery after the treatment, without complications related to replacement of the hematoma with oxygen. Follow-up investigation showed recurrence of the lesion in two patients (5%). Because of its simplicity, reduced invasiveness, and short hospitalization, the procedure presented here is acceptable as an optimal therapeutic modality for chronic subdural hematoma in adults. Theoretical considerations supporting the safety of this procedure are discussed.

Adult↗
PubMed1992

Enzymic method for the spectrophotometric determination of choline in liquor.

A sensitive spectrophotometric method for the determination of choline in liquor is described. The method involves the conversion of choline into formaldehyde by sequential enzymic reactions (choline oxidase and catalase), followed by the formation of a chromophore with 4-aminopent-3-en-2-one. The calibration graph was linear in the range 0.4-15 micrograms cm-3 of choline. The relative standard deviation at 5 micrograms cm-3 of choline was 1.3%. There was no interference from most of the common ingredients of liquor. More than 95% of choline added at two levels was recovered from real samples. The method is simple, and the detection limit was 2 micrograms g-1 when 5 g of sample were assayed.

Alcohol Oxidoreductases↗
PubMed1992

Infantile acute encephalopathy with combined symmetrical hypodensities in the thalami and the putamen on computed tomography.

An eight-month-old boy with clinical features of acute encephalopathy with symmetrical low-density areas in the thalami and the putamen on computed tomography is presented. These particular computed tomography features suggest potential aetiology common to acute encephalopathy with low-density areas in the thalami and infantile bilateral striatal necrosis with an acute onset. The therapeutic consideration of these conditions is also discussed.

Acute Disease↗
PubMed1992

Muscimol suppresses rCGU increase in the substantia nigra after destruction of the caudate nucleus.

Injection of ibotenic acid into the caudate nucleus caused an increase in the uptake of 2-deoxyglucose (2DG) in the ipsilateral substantia nigra pars reticulata (SNr). Increased 2DG uptake was completely suppressed by chronic infusion of muscimol, the gamma-aminobutyric acid (GABA) agonist. While delayed shorter infusion of muscimol from the 3rd to the 7th day, when 2DG accumulation was the most prominent, partially prevented this increase. These data suggest that GABA-mediated transneuronal processes play an important role in the delayed elevation in 2DG uptake in SNR but hyperexcitation due to disinhibition by the loss of GABAergic inputs may play only a partial role in this increase.

Animals↗
PubMed1992

Pure red cell aplasia following autoimmune haemolytic anaemia. Cell-mediated suppression of erythropoiesis as a possible pathogenesis of pure red cell aplasia.

We report here a rare case of pure red cell aplasia (PRCA) following autoimmune haemolytic anaemia (AIHA). After 4 years of AIHA, the patient developed anaemia with severe erythroid hypoplasia and was diagnosed as having PRCA. At this time, Coombs' test was negative and parvovirus infection was not recognized. The patient received azathioprine, and PRCA improved. To determine the pathogenesis of PRCA, in vitro culture studies of erythropoietic and granulopoietic precursors were performed. The patient's serum or IgG did not suppress the colony formation of bone marrow colony-forming units-erythroid (CFU-E) of normal subjects and the patient. In contrast, mononuclear cells in the peripheral blood of the patient significantly suppressed CFU-E of normal subjects. Media conditioned by the patient's mononuclear cells did not significantly suppress CFU-E. The significant production of suppressive cytokine such as tumour necrosis factor or gamma-interferon by the patient's mononuclear cells was not recognized. These findings suggest that the cytotoxic mononuclear cells affected directly the erythropoietic precursors and caused PRCA in this patient. The pathogenesis of PRCA was, therefore, considered to be different from that of the preceding AIHA.

Adult↗
PubMed1992

Electrical alternans of the T-U wave without change in the QRS complex.

A patient with myelocytic leukemia who showed electrical alternans of the T-U wave with no change in the QRS complex following chemotherapy is described. Electrocardiogram taken 4 days later showed ventricular quadrigeminy in which the T-U wave of the first sinus beat after the ventricular premature contraction was markedly less prominent compared to the successive two sinus beats which showed marked prolongation and inverted T-U waves. The causative factors for alternans of T-U waves may include hypochloremic alkalosis with hypopotassemia and myocardial damage by anticancer drugs such as daunomycin and aclarubicin chloride used for the underlying disease.

Aclarubicin↗
PubMed1992

[Assessment of myocardial viability with 201Tl myocardial SPECT 24 hours after injection].

Recently many investigators reported that conventional stress-redistribution myocardial scintigraphy with 201Tl underestimated the presence of ischemic but viable myocardium. We studied the usefulness of 24 hour 201Tl myocardial single photon emission computed tomography (SPECT) to assess myocardial viability and investigated the factors affect to the quality of 24 hour SPECT images. Study patients were consisted with 70 patients with old myocardial infarction (OMI), 72 patients with angina pectoris without OMI (AP) and 43 patients with angiographically proven normal coronary arteries. To obtain SPECT images, 10 minute and 4 hour imagings were sampled 30 seconds per projection. Twenty-four hour imaging was sampled 60 seconds per projection. Twenty-four hour images were visually interpreted as good, moderate and poor quality. Then study patients were divided into 2 groups, group A with good 24 hour images and group B with moderate or poor 24 hour images. One hundred and fifty-eight patients (85.4%) of study patients had 24 hour SPECT images on a good quality. Only 4 patients (2.2%) had poor quality SPECT. All of these 4 patients had broad myocardial infarction. In patients with OMI 61 patients (87.1%), in AP 63 patients (87.5%) and in normal 35 patients (81.4%) had a good 24 hour SPECT. Total sampling counts and myocardial ROI counts were significantly higher in group A than in group B. Body weight was significantly higher and there were more male patients in group B than in group A. Late redistribution was seen in 20 patients (28.5%) with OMI and in 11 patients (15.3%) with AP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[A case of pulmonary alveolar proteinosis and disseminated atypical mycobacteriosis complicating chronic myelogenous leukemia].

A 47-year-old woman with chronic myelogenous leukemia was treated with daily busulfan (total dose approximately 500 mg) from December 1988 to January 1990. The disease thereafter remained stable with no evidence of blastic transformation. In February 1990 she developed productive cough and abnormal acinar lung shadows appeared transiently on her chest X-ray. In October 1990, productive cough and linear and abnormal acinar lung shadows reappeared. Expectorated sputa contained acid-fast bacilli (Gaffky 6, 10). Antituberculous therapy was started, which caused severe liver dysfunction. She was admitted to our hospital for evaluation of abnormal lung shadows. Transbronchial lung biopsy revealed pulmonary alveolar proteinosis with thickening of alveolar septa. The alveolar septal thickening was suspected to be a pathological change following pulmonary alveolar proteinosis. Cultures from sputum, cerebrospinal fluid, and bone marrow aspiration specimens revealed atypical mycobacterium (M. avium complex), and the diagnosis of disseminated atypical mycobacteriosis was established. The pathogenesis of the disseminated atypical mycobacteriosis was considered to be superinfection by mycobacteria.

Busulfan↗
PubMed1992

[Pathophysiological analysis of diabetes mellitus and complications from the urine of diabetic patients].

Of the many information obtainable from the urine of diabetic patients, urinary C-peptide (CPR), albumin and anti-diuretic hormone (ADH) were representatively described using my clinical and experimental data. C-peptide excretion in 24h collection of urine is a good estimate of insulin secretion from the pancreas and thus low in IDDM patients and even in NIDDM patients at a later stage, but high in pathological conditions including Graves' disease, obesity, liver cirrhosis and Cushing's syndrome. Urinary albumin excretion in small amounts (microalbuminuria) is usually observed in diabetic patients who have been under a poor control state of diabetic hyperglycemia for over 5 years and provides a good tool for monitoring early diabetic nephropathy. The grade of microalbuminuria (30-300 mg/day) is positively correlated with the HbA1 level in diabetic patients, showing that microalbuminuria is reversible along with an improvement of diabetic control at least in an early phase of diabetic nephropathy. As the albumin level measured in a spot urine sample correlates well with the value in the 24h collection of urine, the albumin measurement is conveniently feasible with a spot urine sample at every patient's visit. The amount of ADH excreted in urine is 7-10% of that secreted from the posterior pituitary. The excretion of ADH in a day was in the urine of diabetic patients positively correlated with HbA1, urinary osmolarity and concentration of sodium in urine, although the pathological meaning of the observed ADH hypersecretion in the development of diabetic complications is currently unknown.

Albuminuria↗
PubMed1992

[Clinical pharmacology and efficacy of levofloxacin in elderly patients].

We studied a newly developed oral quinolone antimicrobial agent, levofloxacin (LVFX, DR-3355), and obtained the following results. 1. Serum and urine levels of LVFX were determined after oral administration of LVFX 100 mg to 11 elderly patients with various degrees of renal function insufficiencies. The patients were classified according to creatinine clearance (Ccr) values into Group I (n = 1, Ccr greater than or equal to 70 ml/min), Group II (n = 4, 40 less than or equal to Ccr less than 70 ml/min), and Group III (n = 6, Ccr less than 40 ml/min). The peak levels of LVFX did not differ greatly among the 3 groups, but in patients with severely impaired renal functions, serum concentrations decreased more slowly than in those with slightly and moderately impaired renal functions, and high serum levels were maintained over a long period. Urinary excretion of LVFX diminished in relation to degrees of renal failure. 2. LVFX was administered to treat 13 elderly patients with respiratory tract infections. Clinical responses were good in all patients with a high efficacy rate of 100%. Laboratory tests revealed eosinophilia in 1 case. The symptom was mild, however, and no severe side effects due to the drug were observed.

Aged↗