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Biomedical subjects

N Ohsawa

Publications and source records attributed to N Ohsawa.

At least 55 records · Page 3Linked to original sources
PubMed1997

Magnetic resonance imaging and serum aldolase concentration in eosinophilic fasciitis.

We report a 26-year-old man with eosinophilic fasciitis who presented with progressive joint contractures of all four limbs. In this patient, the serum aldolase concentration was elevated while the serum creatinine kinase concentration was normal. Magnetic resonance imaging showed gadolinium enhancement of fascial structures in the lower limbs. With the clinical improvement by the treatment with oral corticosteroid, the aldolase concentration was decreased, and the fascial hyperintensity on magnetic resonance images was reduced. The phenomenon of increased an aldolase concentration accompanied by a normal creatinine kinase concentration may be characteristic of eosinophilic fasciitis. Serial magnetic resonance images and serum aldolase concentration are useful for monitoring the therapeutic response in this condition.

Adrenal Cortex Hormones↗
PubMed1997

Prediction of wall motion improvement after coronary revascularization in patients with postmyocardial infarction: diagnostic value of dobutamine stress echocardiography and myocardial contrast echocardiography.

The diagnostic value of dobutamine stress echocardiography, myocardial contrast echocardiography and dipyridamole stress thallium-201 single photon emission computed tomography (SPECT) for predicting recovery of wall motion abnormality after revascularization was evaluated in 13 patients with postmyocardial infarction. Seventeen segments showed severe wall motion abnormalities before revascularization. Nine segments which had relatively good Tl uptake on delayed SPECT images despite severely abnormal wall motion were opacified during myocardial contrast echocardiography, and showed improved wall motion after revascularization. In contrast, three segments which had poor Tl uptake and severely abnormal wall motion were not opacified during myocardial contrast echocardiography, and showed no improvement in wall motion during dobutamine stress echocardiography and after revascularization. The following three findings were assumed to be signs of myocardial viability: 1) good Tl uptake on delayed SPECT images; 2) improved wall motion by dobutamine stress echocardiography; and 3) positive opacification of the myocardium by myocardial contrast echocardiography. Myocardial contrast echocardiography had the highest sensitivity (100%) and negative predictive value (100%). Delayed SPECT images had the highest specificity (100%) and positive predictive value (100%). Dobutamine stress echocardiography had a sensitivity of 83.0%, specificity of 80.0%, positive predictive value of 90.9%, and negative predictive value of 66.7%, respectively. Myocardial contrast echocardiography showed the lowest specificity (60.0%). The techniques of dobutamine stress echocardiography and SPECT, though noninvasive, may underestimate wall motion improvement after revascularization. Further examination by myocardial contrast echocardiography is recommended to assess myocardial viability for determining the indications for coronary revascularization in spite of its invasiveness.

Cardiotonic Agents↗
PubMed1996

Activation of lavage lymphocytes in lung injuries caused by radiotherapy for lung cancer.

PURPOSE: Radiation pneumonitis sometimes extends beyond the irradiated area of a lung and can also affect the opposite lung. Some immunological mechanisms, in addition to simple direct injury of the lungs by radiation, seem to be involved in the onset of radiation pneumonitis. To clarify such mechanisms, the effects of radiation on local inflammatory cells in lungs, in particular, lymphocytes, were examined. METHODS AND MATERIALS: A comparison was made of bronchoalveolar lavage fluid (BALF) findings from 13 irradiated patients (RT group) and 15 nonirradiated patients (non-RT group) with lung cancer. Patients who later developed radiation pneumonitis (RP group) and those who did not (RP-free group) were also compared. Using a two-color flowcytometer, radiation-induced changes in local inflammatory cells in lungs were analyzed. This included analyses of human leukocyte-associated antigen (HLADR) and intercellular adhesion molecule-1 (ICAM-1) expression on T-cells, which are though to be involved in cell activation and interactions between cells. RESULTS: The following aspects of BALF were higher in the RT group than in the non-RT group: (a) the percentage of lymphocytes and eosinophiles; (b) the incidence of HLADR-positive CD4+T-cells and HLADR-positive CD8+T-cells; and (c) the incidence of ICAM-1--positive T-cells. The following aspects of BALF were higher in the RP group than in the RP-free group: (a) the total cell counts; (b) the percentage of lymphocytes; and (c) the incidence of ICAM-1-positive T-cells. A significant relationship was seen between the incidence of ICAM-1 expression on T-cells and the number of days from the initiation of radiotherapy to the onset of radiation pneumonitis. CONCLUSION: These data suggest that irradiation can induce accumulation of activated T-cells (HLADR and ICAM-1--positive T-cells) in the lung. This accumulation may be closely linked to radiation-induced lung injury. It is also suggested that the incidence of ICAM-1--positive T-cells in BALF may serve as a useful clinical marker of radiation pneumonitis.

Adult↗
PubMed1996

Interruption of pulmonary arterial flow with inadequate ventilation leads to pulmonary infection.

We examined the effect of interruption of pulmonary arterial flow and inadequate ventilation on the development of pulmonary infarction in rats. Pulmonary arterial flow was blocked by the injection of agar into the inferior vena cava and inadequate ventilation was produced by obstructing the left main bronchus with a polypropylene tip. Histological and angiographic examination of the lung demonstrated that: pulmonary artery embolism alone does not induce pulmonary infarction; obstruction of a bronchus does not induce significant changes, but that pulmonary infarction develops when pulmonary artery embolism and obstruction of a bronchus occur simultaneously. It has been thought that pulmonary infarction is caused by acute obstruction of a pulmonary artery, however, the alveolar walls are supplied with oxygen by both the pulmonary circulation and by ventilation. Interruption of pulmonary arterial flow alone is probably not sufficient to induce pulmonary infarction, which is probably caused by deficiency of oxygen supply to the alveolar walls by a synergy between interruption of pulmonary arterial flow and inadequate ventilation.

Animals↗
PubMed1996

Transcriptional activation by the androgen receptor in X-linked spinal and bulbar muscular atrophy.

Polyglutamine tracts encoded by trinucleotide CAG repeats have been found in some transcription factors. Expansion of the polyglutamine tracts in the androgen receptor (AR) has been recognized as a cause of X-linked spinal and bulbar muscular atrophy (SBMA). To study the role of AR as a transcription factor in SBMA, we constructed AR genes encoding expanded polyglutamine tracts (repeat numbers = 52, 92, 132, and 212), and analyzed AR-induced transcriptional activation in NG108-15 cells. We found that AR-induced transcriptional activation gradually decreased with increasing glutamine repeat numbers, and polyglutamine expansion caused a specific reduction in transcription activity in motor neurons. However, the degree of reduction was slight in comparison with the normal AR gene and that of SBMA. Thus, subtle disorders of transcriptional control may occur in SBMA.

Animals↗
PubMed1996

Numerical chromosome aberrations in hepatocellular carcinoma detected by fluorescence in situ hybridization.

AIMS/METHODS: Numerical aberrations of chromosomes 7,8,9,10,12,17,18, X and Y were examined in 38 hepatocellular carcinoma specimens using centromere-specific DNA probes by the fluorescence in situ hybridization method. RESULTS: Numerical aberrations in more than one of the chromosomes examined were found in 27 of 38 (71%) specimens; 6 of 15 (40%) well-differentiated hepatocellular carcinomas; 15 of 17 (88%) moderately differentiated hepatocellular carcinomas; and all of 6 (100%) poorly differentiated hepatocellular carcinomas. Of 6 early hepatocellular carcinomas, numerical chromosome aberrations were detected in 2. The incidence of numerical chromosome aberrations was 93.8% in patients with portal vein thromboses and/or intrahepatic metastases, 52.4% without portal vein thromboses and/or intrahepatic metastases (p < 0.05), while 89.5% of patients with a tumor more than 3 cm in diameter and 50.0% with a tumor less than 3 cm in diameter had chromosome aberrations (p < 0.05). CONCLUSIONS: These results suggest that numerical chromosome aberrations start to occur in the early stage of hepatocellular carcinoma and to accumulate during tumor progression.

Carcinoma, Hepatocellular↗
PubMed1996

Hypoparathyroidism and insulin-dependent diabetes mellitus in a patient with Kearns-Sayre syndrome harbouring a mitochondrial DNA deletion.

We report a 17-year-old girl with short stature, external ophthalmoplegia, atypical retinal pigmentary degeneration, sensorineural hearing loss, and cardiac conduction defect (Kearns-Sayre syndrome). A large-scale deletion (6741 base pairs) in mitochondrial DNA was found in her muscle specimen. She also had insulin-dependent diabetes mellitus (IDDM). On admission, her plasma glucose level was elevated at 31.0mmol/l with mild ketoacidosis, and haemoglobinA1c elevated at 16.5%. After improvement of diabetic ketoacidosis, she was placed on insulin 24-30 units/day despite her small body weight of 25 kg. There was reduced excretion of urinary C-peptide at 3.97 nmol/day. In addition, she had idiopathic hypoparathyroidism with a serum calcium level of 2.15 mmol/l, phosphate 1.7 mmol/l, and intact PTH below 10 ng/l. Human leucocyte associated antigen typing showed A24, A26; B54, B61; CW1, CW3; DR8, DR14; DQ1 and DQ3, suggesting that the presence of HLA-A24 and CW3 antigen contributed to the association of IDDM and hypoparathyroidism, similar to Japanese patients with polyglandular autoimmune syndrome, complicated by hypoparathyroidism and IDDM. We suggest that a genetic linkage, as well as mitochondrial dysfunction, may be responsible for the association of the two disease states. This is an extremely rare case of Kearns-Sayre syndrome, presenting in association with IDDM and idiopathic hypoparathyroidism.

Adolescent↗
PubMed1996

Differences in response of thyrotropin to 3,5,3'-triiodothyronine and 3,5,3'-triiodothyroacetic acid in patients with resistance to thyroid hormone.

This study investigated the response of TSH secretion to 3,5,3'-triiodothyronine (T3) and 3,5,3'-triiodothyroacetic acid (Triac) in patients with resistance to thyroid hormone, and compared the responses with those in patients with TSH-secreting pituitary adenoma and normal subjects. A short-term administration of 75 microg of T3 daily for 7 days suppressed serum TSH concentrations almost completely in normal subjects, but suppressed TSH only partially in patients with resistance to thyroid hormone and TSH-secreting pituitary adenoma. A single-dose administration of 75 microg of T3 gave similar results in regard to TSH suppressibility in these three subjects groups. In contrast, a single-dose administration of 1.4 mg of Triac remarkably suppressed serum TSH concentrations after 2 hours in not only normal subjects (-34 +/- 11% [mean +/- SD] from the basal value) but also in patients with resistance to thyroid hormone (-31 +/- 9%), and this TSH suppression continued for 4 hours. After 24 hours, this TSH suppression persisted in normal subjects (-62 +/- 12%) but was relieved in patients with resistance to thyroid hormone (-23 +/- 14%). After the Triac administration, molar ratios of alpha-subunit to TSH in serum were decreased in patients with TSH-secreting pituitary adenoma but increased in patients with resistance to thyroid hormone. Because the Triac therapy for patients with resistance to thyroid hormone suppressed pituitary-TSH secretion during the early phase of drug ingestion, this drug should be given several times within a day to obtain continuous TSH-suppressive effects.

Adenoma↗
PubMed1996

Rheumatoid factor in the serum of hepatitis C virus-infected patients: an increase in the titre during cold storage.

Storage of serum at 4 degrees C elevated the titre of rheumatoid factor (RF) as measured by nephelometry with IgG-coated latex in 12 of 38 specimens positive for hepatitis C virus. Increased RF following cold storage was not detected in HCV-negative sera. Most of the sera showing the cold-dependent elevation of RF had decreased complement hemolytic activity (CH50) after the cold storage. The RF titre elevated by cold storage decreased to the level of fresh serum by the addition of guinea pig serum as a complement supplement in a dose-dependent fashion. Thus, in the serum of some HCV-infected patients, the affinity of RF appears to be weak, and the binding between the RF and IgG coated on latex may be inhibited by the complement components of fresh serum.

Cold Temperature↗
PubMed1996

A variant of adenomatous goiter with characteristic histology and possible hereditary thyroglobulin abnormality.

A variant type of adenomatous goiter was identified in 24 of 2160 patients with adenomatous goiter who underwent thyroidectomy. The characteristics of the thyroid gland in these 24 patients included large goiter, small follicles, scant colloid, and columnar follicular cells containing yellow-green granules on hematoxylin-eosin staining. The thyroid gland was slightly orange-red, and electron microscopic examination showed abundant lysosomes with colloid droplets. When comparing the features of this group with those of 24 patients with common adenomatous goiter, the incidence of familial predisposition to thyroid diseases in the former group was higher. The age at the time of detection of goiter was lower, i.e. 17 +/- 15 vs. 44 +/- 17 yr (P < 0.001, variant type vs. common type), the serum total T4 concentrations were lower (84 +/- 21 vs. 103 +/- 18 nmol/L; P < 0.01), and the serum TSH concentrations were higher (2.4 +/- 2.1 vs. 1.0 +/- 0.9 mU/L; P < 0.01). Thyroid radioiodine uptake was remarkably increased (49 +/- 22 vs. 16 +/- 9%; P < 0.001), and lower levels of serum thyroglobulin were noted (33 +/- 51 vs. 484 +/- 603 micrograms/L; P < 0.01). The thyroglobulin content was low in the thyroid gland studied. The data suggest that the etiology of this variant type of goiter is a hereditary abnormality in thyroglobulin synthesis, and this type of goiter may be distinguished from common adenomatous goiter by the characteristic morphology of the thyroid gland in addition to clinical findings.

Adult↗
PubMed1996

Changes in thyroid volume in response to radioactive iodine for Graves' hyperthyroidism correlated with activity of thyroid-stimulating antibody and treatment outcome.

This study investigated 1) the relationship between thyroid volume and thyroid function in radioactive iodine (RAI) treatment for Graves' disease, and 2) the activity of thyroid-related Ig in serum on the responsiveness of thyroid tissue to RAI. The changes in thyroid volume per megabecquerel (MBq) of 131I retained in thyroid tissue was calculated by ultrasonography as a quantitative indicator of the effect of RAI on thyroid volume. Of the 52 patients treated with 131I (3.7 MBq retained/g thyroid tissue), 26 patients showed thyrotoxicosis, 20 patients became euthyroid, and 6 patients developed hypothyroidism 6 months after therapy. The change in thyroid volume per MBq 131I was lower (P < 0.01) in the hyperthyroid patients than in the euthyroid or hypothyroid patients. The activity of thyroid-stimulating antibody in serum immediately before the therapy was greater (P < 0.01) in the hyperthyroid patients than in the euthyroid patients and was greater (P < 0.05) in the euthyroid patients than in the hypothyroid patients; it was inversely correlated with the changes in thyroid volume per MBq 131I (r = -0.667; P < 0.01). Accurate measurement of changes in thyroid volume during the course of RAI treatment provides evidence of the responsiveness of Graves' disease thyroid tissue to RAI, which is related to the outcome of thyroid function. Thyroid-stimulating antibody determination may be useful in deciding the appropriate dose of RAI to obtain euthyroidism instead of hyperthyroidism.

Adult↗
PubMed1995

Serial MRI in early Creutzfeldt-Jacob disease with a point mutation of prion protein at codon 180.

We report a 66-year-old woman with histologically diagnosed Creutzfeldt-Jacob disease (CJD), followed with MRI from an early clinical stage. MRI demonstrated expansion of the high cortical signal on T2-weighted images, which differs from previous MRI reports of CJD. This patient followed an atypical clinical course: 16 months had passed before she developed akinetic mutism, and periodic sharp waves had not been detected on EEG after 2 years in spite of her akinetic mutism. Brain biopsy showed primary spongiform changes in the grey matter, and a point mutation of the prion protein gene at codon 180 was discovered using polymerase chain reaction direct sequencing and Tth 111 I cutting. This is the first case with the point mutation of the codon 180 variant with an atypical clinical course and characteristic MRI findings.

Aged↗
PubMed1995

A patient with diabetes mellitus, cardiomyopathy, and a mitochondrial gene mutation: confirmation of a gene mutation in cardiac muscle.

A 44-year-old woman with diabetes mellitus, cardiomyopathy, and a mitochondrial gene mutation, was reported. She was diagnosed as having diabetes at 33 years of age and was treated with insulin. However, she stopped treatment 6 months later and had no medical care until she developed diabetic ketoacidosis at 41 years of age. She had diabetic foot, diabetic retinopathy, and nephropathy with low insulin secretory capacity, leading to insulin treatment. A point mutation of the mitochondrial tRNA(Leu(UUR)) gene was identified in peripheral leukocytes at 43 years of age, and sensorineural hearing impairment was detected at the same time. Her mother also suffered from diabetes mellitus with deafness and her son, who was not diabetic at age 19, had the same mitochondrial DNA (mtDNA) mutation. At 44 years of age, she developed congestive heart failure due to cardiomyopathy, and the same mtDNA mutation was identified in the cardiac muscle. Thus, it is very likely that in this patient, diabetes and cardiomyopathy was caused by the same abnormality, the point mutation of mitochondrial tRNA(Leu(UUR)) gene.

Adult↗
PubMed1995

Oval pupil in patients with diabetes mellitus: examination by measurement of the dark-adapted pupillary area and pupillary light reflex.

Determination of the dark-adapted pupillary area (DAPA) by infrared photography revealed that some diabetic patients show corectopia (oval pupil) in addition to the small DAPA as pupillary abnormalities. The prevalence and clinical details of oval pupil were compared between diabetic patients and healthy subjects. Pupillary light reflexes were also analyzed with an infrared videopupillography in some of the diabetic patients. The healthy subjects were examined for the influence of age on the ratio of the pupillary diameter of the major and minor axes. The ratio was 1.04 +/- 0.02 (mean +/- S.D.) in the healthy subjects, and cases in which the ratio was +2 S.D. or higher than the mean ratio were defined as oval pupil. Oval pupil was observed in 21 (24%) of 86 diabetic patients, and was correlated with heart rate variation (P < 0.05) and DAPA (P < 0.01), which represent an autonomic dysfunction. Quantitative analysis of pupillary light reflexes with an infrared videopupillography revealed that the dark-adapted pupillary area before photic stimulation (P < 0.01) and the maximum %-velocity of constriction (P < 0.05) were significantly less in the oval pupil group than in the round pupil group. Cranial magnetic resonance imaging revealed no abnormalities in the oval pupil group. From these results, a peripheral autonomic disorder was implicated in the etiology of oval pupils in diabetic patients.

Adult↗
PubMed1995

Coronary angioplasty of chronic total occlusions with bridging collateral vessels: immediate and follow-up outcome from a large single-center experience.

OBJECTIVES: The purpose of the present study was to assess the effect of bridging collateral vessels on the success of coronary angioplasty of chronic total occlusions in the context of state of the art technology and operator skill. BACKGROUND: Coronary angioplasty of chronic total occlusions has been associated with relatively low success rates. Because the presence of bridging collateral vessels in chronic total occlusion has been reported to be the major predictive factor in procedural failure, angioplasty is often not recommended in patients with such vessels. METHODS: Three hundred ninety-seven consecutive patients undergoing coronary angioplasty for chronic total occlusion were classified into two groups. Patients in group I had chronic total occlusion with bridging collateral vessels (97 patients, 109 total occlusions), and patients in group II had chronic total occlusion without such vessels (300 patients, 324 total occlusions). RESULTS: The mean +/- SD duration of occlusion was 46 +/- 66 months (range 2 to 170) in group I and 27 +/- 39 months (range 2 to 112) in group II (p < 0.05, high power value 0.83, group I vs. group II). Angioplasty for single-vessel disease was performed in a smaller proportion of patients in group I than in group II (22% vs. 36%, p < 0.05; power value 0.77). Procedural success was achieved in 82 chronic total occlusions in group I and 270 chronic total occlusions in group II (75% vs. 83%, p = 0.07; power value 0.53). The rates of restenosis and reocclusion were 54% and 16%, respectively, for group I and 56% and 13%, respectively, for group II (p = 0.76, 0.46; power value 0.51, 0.47). Complications were minor with no Q wave infarction or requirement for urgent bypass surgery in either group. Of 81 patients with unsuccessful coronary angioplasty, 1 patient from group I (1%) and 3 patients from group II (1%) required pericardiocentesis because of cardiac tamponade. Guide wire manipulation did not impair the flow of bridging collateral channels in group I. CONCLUSIONS: Coronary angioplasty can open chronic total occlusions, with or without bridging collateral channels, for safe and effective recanalization without major complications.

Aged↗