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Biomedical subjects

N Ohsawa

Publications and source records attributed to N Ohsawa.

At least 19 recordsLinked to original sources
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↗
PubMed1995

In situ localization of ribosomal RNAs is a reliable reference for hybridizable RNA in tissue sections.

Assessments of RNA integrity and its hybridizability are essential for successful implementation of in situ hybridization (ISH) for mRNA or viral RNA, particularly when paraffin-embedded specimens from surgical, biopsy, and autopsy cases are used. In this study, we examined the suitability of ISH of 28S ribosomal RNA (rRNA) for this purpose. Oligo-DNA with nucleotide sequences complementary to a well-conserved segment of 28S rRNA with auxiliary adenine-thymine-thymine (ATT) repeats at the 3' and 5' ends was synthesized. The oligo-DNA was made antigenic by converting the adjacent thymines to T-T dimers by UV irradiation and was used as a probe for ISH of 28S rRNA. The T-T dimers were detected by enzyme immunohistochemistry. When the results of ISH rRNA staining and that of total RNA staining by methyl green/pyronin Y were compared for various types of sections prepared from rat and human tissues, the staining intensities of total RNA did not always match those of ISH rRNA staining. In paraffin sections of formalin-fixed tissues, the degree of proteinase digestion influenced the ISH rRNA staining intensity, whereas it had no effect on the total RNA staining intensity. The intensities of ISH rRNA staining agreed well with those of various types of mRNA staining by ISH in 10 cases of paraffin-embedded pathological specimens. We therefore believe that ISH rRNA staining is a convenient parameter for evaluation of levels of hybridizable RNAs in tissue sections.

Animals↗
PubMed1995

Assessment of the severity of coronary artery disease by thallium-201 washout rate after dipyridamole infusion--a coronary hemodynamic and metabolic study.

This study examined the relationship between the myocardial washout rate (WR) of thallium-201 (201Tl) in dipyridamole scintigraphy and both coronary flow reserve (CFR) and myocardial lactate extraction rate (LER) after dipyridamole infusion in 31 patients with coronary artery disease (CAD) without myocardial infarction and 16 control patients. Patients with CAD demonstrated significantly lower WR (21 +/- 17 vs 43 +/- 10%, p < 0.001), lower CFR (128 +/- 82 vs 242 +/- 89%, p < 0.001) and lower LER (-2 +/- 20 vs 10 +/- 10%, p < 0.05) than did the control patients. WR was significantly correlated with CFR (r = 0.50, p < 0.001) and LER (r = 0.41, p < 0.01) in all of the patients. CAD patients with dipyridamole-induced chest pain demonstrated significantly lower WR (14 +/- 20 vs 27 +/- 12%, p < 0.05), lower CFR (97 +/- 71 vs 162 +/- 82%, p < 0.05) and lower LER (-13 +/- 21 vs 11 +/- 9%, p < 0.001) than did CAD patients without chest pain. CAD patients with dipyridamole-induced ST depression demonstrated significantly lower WR (14 +/- 20 vs 29 +/- 8%, p < 0.05), lower CFR (105 +/- 79 vs 170 +/- 73%, p < 0.05) and lower LER (-8 +/- 21 vs 11 +/- 10%, p < 0.01) than did CAD patients without ST depression. These results suggest that the myocardial washout rate of 201Tl after dipyridamole infusion reflects the severity of coronary artery disease as assessed by coronary hemodynamics, myocardial metabolism, symptoms and electrocardiography.

Aged↗
PubMed1995

Serum concentrations of granulocyte colony-stimulating factor (G-CSF) determined by a highly-sensitive chemiluminescent immunoassay during the clinical course of subacute thyroiditis.

Granulocyte colony-stimulating factor (G-CSF) concentrations in serum were determined for the first time by a newly developed and highly sensitive chemiluminescent immunoassay (the limitation of detection, 0.5 pg/ml) in ten patients with subacute thyroiditis, during treatment with glucocorticoid or indomethacin. Before therapy, circulating neurophil counts significantly increased to 5.15 +/- 2.07 x 10(3)/microliters compared with the convalescent phase (2.94 +/- 1.07 x 10(3)/microliters), and the data were correlated with individual serum G-CSF levels (r = 0.854, P < 0.01). Serum concentrations of interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were less than the detectable threshold of ELISA. During two weeks of glucocorticoid therapy, although the circulating neutrophil counts increased from 5.15 +/- 2.46 x 10(3)/microliters to 7.73 +/- 1.64 x 10(3)/microliters (P < 0.01), serum G-CSF levels were depressed from 25.1 +/- 15.3 pg/ml to 13.8 +/- 13.9 pg/ml (P < 0.01). These data indicate that G-CSF is one of the mediators of the increase of neutrophils in subacute thyroiditis, while it does not contribute to steroid-induced neutrophilia.

Adult↗
PubMed1995

Chaotic behavior of hemodynamics with ventricular assist system.

In order to analyze hemodynamic parameters during left ventricular assistance as an entity and not as decomposed parts, non-linear mathematical techniques were utilized. Pneumatically actuated ventricular assist systems (VAS) were implanted as left heart bypasses in acute animal experiments, using healthy adult mongrel dogs. By the use of the non-linear mathematical technique, the arterial blood pressure waveform (AP) was embedded into the four-dimensional phase space and projected into the three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to the graphical analysis of the state space. The phase portrait of the attractor showed a complex structure; a three dimensional solid torus with a screw type structure as a part, suggesting deterministic chaos in the AP without left ventricular assistance. Positive lyapunov exponents confirmed the existence of chaos. During counterpulsation mode left ventricular assistance, the phase portrait of the attractor showed a more complex structure, and positive Lyapunov exponents suggested a greater dimensional deterministic chaos. However, non-structured patterns were seen in the phase space during internal mode VAS driving, suggesting the possibility of dissipative dynamics in the four dimensional phase space. These results suggest that the cardiovascular system with counterpulsation mode VAS driving is in a homeochaotic state, which is thought to be a flexible and intelligent control system. And there is greater dimensional complex dynamics in the circulatory regulatory system with VAD during internal mode assistance.

Animals↗
PubMed1995

[Intracranial tuberculoma with spontaneous recovery].

A 57-year-old man was admitted because of headache, nausea, and fever up (38 degrees C). He showed nuchal rigidity slightly. CSF analysis showed 833 white blood cells (WBC) (80% monocyte), protein value of 68 mg/dl, glucose level of 36 mg/dl and ADA level of 11.8 IU/l. Brain pre-contrast CT indicated high density area in right parietal lobe, and it showed slightly homogeneously enhancement with contrast medium. MRI on T2 WI demonstrated hypointense lesion with bright central core in right parietal lobe. The lesion showed isointense on T1WI, and indicated homogeneous enhancement with Gd-DTPA. He was sent to our hospital after one week. With only antibiotics the symptoms were relieved and the CSF findings improved during the previous hospital. However, Mycobacterium tuberculosis (M. tuberculosis) DNA was detected in CSF by PCR amplification, and he recovered completely with anti-tuberculous treatment. This case was interesting to reveal atypical features of spontaneous recovery. Since Shankar's study using polymerase chain reaction (PCR) for detection of M. tuberculosis in cerebrospinal fluid (CSF), the PCR assay have been recognized to be a rapid method for diagnosis of tuberculous meningitis (TBM). But there are problems of PCR sensitivity when dealing with CSF samples containing small amount of M. tuberculosis DNA. Comparing direct PCR with nested PCR, we studied on the evaluation of PCR for diagnosis of TBM. In this study the nested PCR was positive in all CSF specimens from 4 patients with TBM, but we could not detect M. tuberculosis DNA by only the direct PCR. Nested PCR amplification improved the sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[A case of primary thyroid T-cell lymphoma with infiltration of lymphoma cells in peripheral blood: diagnosed by DNA analysis].

A 57-year-old woman came to our hospital with complaints of neck swelling and headache in 1991. She was diagnosed as having chronic thyroiditis in euthyroidism because she had a diffuse goiter with both antithyroglobulin antibody (TGHA) and antimicrosomal antibody (MCHA). In 1992, she complained of the rapid growth of her thyroid gland and a swallowing disturbance. Atypical lymphocytes were observed in 16.5% of leukocytes in peripheral blood and similar atypical cells were found in bone marrow. Although an ultrasound scan of the thyroid gland revealed a symmetrical enlargement without a pseudocystic appearance, cytological study with fine needle aspiration biopsy of the thyroid gland demonstrated an abundance of atypical lymphoid cells. A whole body scintigram with 67gallium citrate showed no significant accumulation except in the thyroid gland. With a diagnosis of suspected primary thyroid lymphoma, total thyroidectomy was performed. However the diagnosis of malignant lymphoma was not confirmed histologically. A study of lymphocytes subset with two-color flow cytometry, which was performed for both lymphocytes in peripheral blood and infiltrating lymphocytes in the resected thyroid gland, revealed abnormal increased CD4 positive T cells and decreased HLA-DR expression. Additionally, southern blot DNA analysis for abnormal lymphocytes using restriction enzymes, EcoRI and BamHI, demonstrated rearrangement of the T-cell antigen receptor, which indicates a monoclonal proliferation of lymphocytes. After total thyroidectomy, atypical lymphocytes in peripheral blood decreased, and circulating autoantibodies including TGHA and MCHA disappeared. From these data, this patient was finally diagnosed as having a primary T-cell lymphoma of the thyroid gland, which is a very rare type of thyroid lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1994

Sequence analysis of the thyrotropin (TSH) receptor gene in congenital primary hypothyroidism associated with TSH unresponsiveness.

Congenital primary hypothyroidism due to thyrotropin (TSH) unresponsiveness is a very rare disorder and only a few cases have been documented previously. To elucidate whether structural abnormalities in the TSH receptor (TSHR) could be a primary underlying mechanism of this disorder, we analyzed nucleotide sequence of the entire coding region of the TSHR gene in three patients diagnosed with congenital primary hypothyroidism associated with TSH unresponsiveness. Diagnosis of TSH unresponsiveness was largely made based on the following criteria: (a) congenital primary hypothyroidism with autosomal recessive inheritance, (b) a nongoitrous thyroid gland in a normal position with low thyroidal radioactive iodine uptake, (c) normal in vitro TSH bioactivity or absent in vivo response to exogenous TSH, and (d) absence of thyroid autoantibodies. The TSHR cDNA was successfully obtained from RNA of peripheral mononuclear leukocytes with reverse transcription and polymerase chain reaction, and was sequenced directly. Comparison of these nucleotide sequences with the normal TSHR sequence revealed no difference in the predicted amino acid sequence with a heterozygous polymorphism in codon 601 in one patient, indicating absence of TSHR structural abnormalities in these patients. Our results indicate that congenital primary hypothyroidism associated with TSH unresponsiveness is unlikely to be due to mutations in the TSHR-structure gene.

Adult↗
PubMed1994

Fluctuations of the sympathetic nerve discharges in animals without natural heartbeat.

To assess the effect of artificial circulation on the circulatory regulatory system, rhythmical fluctuations in the cardiovascular system and autonomic nerve discharges were analyzed in animal experiments using adult mongrel dogs. Two pneumatically actuated ventricular assist devices were implanted as total biventricular bypass (BVB) under general anesthesia; then, the natural heart was electrically fibrillated to constitute the BVB part of the complete prosthetic circulation model. All hemodynamic data and sympathetic nerve discharges were recorded and calculated in the computer system by the use of spectral analyzing methods. In the power spectrum of the arterial blood pressure waveform during prosthetic circulation, the Mayer wave peak was significantly decreased though the respiratory wave peak was not significantly changed. However, the Mayer wave peak in sympathetic nerve discharges was significantly increased though the respiratory wave peak was not significantly changed. These results suggest that rhythmical fluctuations are a necessary response of the circulatory regulatory system including the autonomic nervous system. However, sympathetic nerve discharges respond to the artificial heart without rhythmical fluctuations.

Animals↗
PubMed1994

[An adult case of tethered cord syndrome with lipoma and thoraco-lumbar syringomyelia presenting slow progressive muscular atrophy in the lower limbs].

A 23-year-old man developed slowly progressive muscle weakness from the age of 10, followed by paresthesia and urinary disturbance. The physical examination showed bilateral muscular atrophy in the lower limbs and dissociated sensory disturbance below Th8. Although there was normal appearance of spinal X-P, MRI revealed conus medullaris at S2 involved thoraco-lumbar syringomyelia with extramedullary lipoma. After the operation for laminectomy of L5-S2 and untethering without direct surgery for syringomyelia, post-operated MRI exhibited definite shrinkage of the syrinx. It suggested that thoraco-lumbar syringomyelia in the present case was not congenital anomaly, but secondary outcome to tethered cord syndrome.

Adult↗
PubMed1992

Growth-inhibitory action of an estrogen-chlorambucil conjugate (KM2210) in human breast cancer cell line MCF-7: its relation to reduction of estrogen receptor and transforming growth factor-alpha secretion.

We investigated the effects of a benzoate of an estradiol-chlorambucil conjugate (KM2210) and chlorambucil on growth, estrogen receptor, and secretion of transforming growth factor (TGF)-alpha in the hormone-dependent human breast cancer cell line MCF-7. In the presence of 10(-10)-10(-6) M KM2210, the estrogen-induced growth of MCF-7 was completely inhibited. Inhibited growth of MCF-7 treated with 10(-8) or 10(-6) M KM2210 for 4 days was not rescued by removal of the drug and the addition of estradiol. By treatment of MCF-7 with KM2210 for 4 days, estrogen receptor-binding sites were decreased at 10(-8) M and were not detected at 10(-6) M but were unaltered by 10(-8) M chlorambucil. Moreover, estrogen receptor immunoreactivity and the level of estrogen receptor mRNA were decreased through treatment with 10(-6) M KM2210 for 4 days. These suppressions occurred prior to the onset of inhibitory action on MCF-7 growth. Secretion of TGF-alpha from MCF-7 was decreased by 4 days of treatment with 10(-8) and 10(-6) M KM2210 but not with chlorambucil. The addition of exogenous TGF-alpha generally restored the growth of MCF-7 treated with 10(-8) M KM2210. We concluded that KM2210 has irreversible or at least long-standing inhibitory effect on estrogen-dependent growth of MCF-7. It is conceivable that the decrease of estrogen receptor renders the cell unable to respond to estrogen with increased TGF-alpha secretion and succeeding cell growth.

Antineoplastic Agents↗
PubMed1992

Comparative studies by cell culture and in vivo implantation test on the toxicity of natural rubber latex materials.

Colony assay using V79 cells, the agar diffusion assay with L929 cells, and the 7-day rabbit muscle implantation test were employed to evaluate the cytotoxicity and tissue toxicity of natural rubber latex (NRL) materials. The in vivo implantation test showed that, among 13 histological parameters, thickness of inflammatory layer was the most useful index to evaluate tissue responses quantitatively. A comparison of the in vivo and in vitro parameters revealed the following correlations between the thickness of the inflammatory layer and cytotoxicity indices: Colony assay of the extracts, IC50: r = 0.80; Agar diffusion assay, Zone index: r = 0.73; Lysis index: r = 0.61. From these results, it appears that the colony assay provides a more reliable prediction of the tissue response than the agar diffusion assay.

Animals↗
PubMed1992

Postprandial hypotension in patients with non-insulin-dependent diabetes mellitus.

This study attempted to determine whether postprandial hypotension (PPH) is associated with diabetes mellitus by 24-h ambulatory blood pressure monitoring (24-h ABPM) and by monitoring blood pressure during 75-g oral glucose tolerance test (75-g OGTT) in 15 normal subjects and 35 patients with non-insulin-dependent diabetes mellitus. When we defined PPH as a postprandial decrease in systolic blood pressure of greater than 20 mmHg, the incidence of PPH in diabetics was 37% by 24-h ABPM and 20% by 75-g OGTT. The incidence of proliferative retinopathy and proteinuria was greater in diabetics with PPH than in those without PPH. All of the patients with PPH had somatic and autonomic neuropathy. The C-peptide response was lower in diabetics with PPH than in those without PPH. We revealed the presence of PPH in diabetics, and found that PPH was closely related to disease severity, especially diabetic autonomic neuropathy.

Adult↗
PubMed1992

Peroxidase and coupling activities of thyroid peroxidase in benign and malignant thyroid tumor tissues.

The coupling activity of thyroid peroxidase (TPO) in thyroid glands from patients with benign adenoma, papillary carcinoma, and diffuse goiter (Graves' disease) was measured for the first time, in addition to the peroxidase activity of these tissues. The peroxidase activity of TPO in the mitochondria-microsomes fraction was measured with guaiacol or iodide as the second substrate. In the case of papillary carcinoma, the mean protein-based specific activity obtained by the guaiacol assay was about 1/7 of that of diffuse goiter. The iodide oxidation activity of carcinoma was very low, about 1/25 [corrected] of that in diffuse goiter and 1/70 of that in adenoma. The peroxidase activity in adenoma was almost similar in the guaiacol oxidation assay and approximately one half in the iodide oxidation assay as compared with that in diffuse goiter. There was a close correlation between the guaiacol and iodide oxidation assays in individual patients with adenoma and diffuse goiter, but not in patients with papillary carcinoma. The coupling activity of TPO was measured with thyroglobulin purified from pooled toxic diffuse goiters and chemically iodinated to contain little additional T3 and T4. The specific coupling activity of TPO in mitochondria-microsomes from carcinoma was significantly lower (about 1/5) than that of diffuse goiter, and the activity in adenoma was not significantly different (about 1/2) from that of diffuse goiter. The data of coupling activities has a close correlation with that of peroxidase activities in individual patients with adenoma but not in patients with carcinoma. Based on these findings, the qualitative abnormality of TPO and its relation to the cold 123I scintigram in thyroid tumors are discussed.

Adenoma↗
PubMed1992

Thyroid-stimulating antibodies and thyroid stimulation-blocking antibodies during the pregnancy and postpartum period: a case report.

This report describes a unique pattern of changes in thyroid function and thyroid antibodies in a woman during the course of two pregnancies and two postpartum periods. A 25-year-old woman developed hypothyroidism in the postpartum period after the delivery of her first child. She was found to have potent thyroid stimulation-blocking antibodies (TSBAb) in the serum. One year later, she became pregnant again, and during the pregnancy, TSBAb had decreased to an undetectable level. She gave birth to the second healthy child and developed postpartum thyrotoxicosis, probably due to destruction of the thyroid gland, which gradually resolved. In this postpartum period, serum TSBAb levels increased. Eight months postpartum, she developed what appeared to be Graves' disease with an elevated 123I-thyroid uptake. Serum thyroid-stimulating antibodies (TSAb) were found at that time, and the TSBAb had disappeared from her serum.

Adult↗
PubMed1992

Epithelial hyperplasia and decreased colloid content of the thyroid gland in triiodothyronine-predominant Graves' disease.

Patients with T3-predominant Graves' disease have an increased serum T3 level despite a normal or even lower level of serum T4 caused by antithyroid drug treatment. This study investigated the morphological characteristics of the thyroid gland in this type of hyperthyroidism. Ultrasound showed a similar thyroid echogenicity in both T3-predominant and ordinary Graves' disease, but thyroid weight was significantly greater in T3-predominant Graves' disease than in the controls [91 +/- 37 g vs. 48 +/- 17 g (mean +/- SD); P < 0.01]. The height of thyroid follicular epithelial cells were significantly greater in T3-predominant Graves' disease than in the controls (9.6 +/- 1.0 vs. 6.4 +/- 1.1 microns), but the epithelial height did not correlate significantly with the serum TSH receptor antibody titers. Epithelial cells occupied 26.4 +/- 10.9% of the total thyroid tissue in T3-predominant Graves' disease, while they occupied only 14.5 +/- 6.8% in the controls. Intracolloidal vacuoles also occupied a significantly greater area in the T3-predominant group (6.6 +/- 3.9% vs. 1.9 +/- 1.0% for controls). These findings suggest that the thyroid gland is more active in T3-predominant Graves' disease and has a more rapid turnover of intrathyroidal iodine than in the ordinary type of Graves' disease.

Adolescent↗