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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 559 records · Page 31Linked to original sources
PubMed1995

Sequential MR signal change of the thrombus in the false lumen of thrombosed aortic dissection.

The evolution of thrombus in the false lumen was investigated in 14 patients with thrombosed aortic dissection, by reviewing the findings acquired at a total of 21 magnetic resonance imaging (MRI) examinations performed between 2 and 146 days after the onset. On electrocardiographic gated 1.5-Tesla MRI, T1-(TR/TE = 860 +/- 190 ms/17-40 ms) and T2-(TR/TE = 1620 +/- 240 ms/70-80 ms) weighted spin echo and gradient echo images were obtained, and the signal intensity of the thrombus on these images was evaluated independently by two observers. The density of the thrombus was also evaluated using computed tomography (CT) images obtained at a total of 54 examinations. On both T1- and T2-weighted images, the thrombus showed signal iso- or hypointensity compared to that of skeletal muscle during the first several days after the onset and, thereafter, showed signal intensity similar to that of fat tissue. It is suggested that the low signal intensity of the thrombus observed during the initial period after the onset was caused by the presence of deoxyhemoglobin and the high intensity observed thereafter was caused by methemoglobin. Focal discrepancy of the signal intensities within two parts of the lumen on spin echo images was observed in 7 patients, and a low-intensity layer on the surface of the thrombus inside the false lumen was observed on gradient echo images in 5 of these 7 patients. This characteristic MR signal change of the thrombus in the false lumen of thrombosed aortic dissection provides useful information concerning the age of the thrombus and in the differential diagnosis of the thrombus from a mural thrombus of aortic aneurysm.

Adult↗
PubMed1995

Expression of EGF, EGFR and PCNA in laryngeal lesions.

The expression of EGF/EGFR in 47 laryngeal surgical specimens from 44 patients was examined. PCNA analysis as an index of proliferating cells was also performed in 32 cases of laryngeal cancer, six cases of pre-cancerous lesions and nine cases of normal laryngeal mucosa. EGFR failed to show a significant correlation with tumour behaviour, but EGF expression was statistically significantly higher in malignant (SCC) than in non-malignant tissues (pre-cancerous and normal tissues) (p < 0.006), and PCNA also showed a statistically significant difference (p < 0.016) between the two. In malignant tissues when EGF/EGFR in 'double-positive' and 'double-negative' cases was compared, a statistically significant difference in PCNA was found (p < 0.029); but this was not seen in non-malignant tissues. Our results support the hypothesis that an autocrime mechanism exists in laryngeal cancer and in this mechanism EGF may play an important role in tumour progression, especially when EGFR is overexpressed.

Adult↗
PubMed1995

Enhancement of hematopoietic uptake by granulocyte colony-stimulating factor in Ga-67 scintigraphy.

The authors report on two non-Hodgkin's lymphoma cases which showed markedly enhanced Ga-67 uptake of granulopoietic area induced by recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration. The rhG-CSF is a newly developed agent for reduction of infections, which stimulates the proliferation and differentiation of granulopoiesis. Use of rhG-CSF is becoming increasingly frequent because the indications are so broad that most patients with intensive chemotherapy for malignancies benefit from undergoing this treatment. In this study, the results of the two cases were: 1) G-CSF enhanced the accumulation of Ga-67 citrate in the granulopoietic area; 2) the marked uptake of red marrow looked like involvement; and 3) in contrast, the involved area became relatively "cold." These findings should be considered in the interpretation of Ga-67 scintigraphy.

Adult↗
PubMed1995

I-123 iodoamphetamine lung scanning in patients with ventilation-perfusion mismatching.

I-123 IMP is a nonparticulate agent and becomes trapped by endothelial membranes in the pulmonary capillaries. Using I-123 IMP, the authors studied six patients with ventilation-perfusion mismatch. Three of six patients had pulmonary thromboembolism, and three had pulmonary hypertension. In comparison with conventional perfusion lung scanning using Tc-99m MAA, defect sizes visualized by I-123 IMP were smaller in all patients. I-123 iodoamphetamine is a useful agent for assessing the perfusion of pulmonary arterial microvasculature which Tc-99m MAA fails to penetrate.

Amphetamines↗
PubMed1995

Inferior vena cava occlusion with pulmonary embolism because of complications due to ruptured abdominal aneurysm demonstrated by radionuclide venography.

A 66-year-old man with an abdominal aortic aneurysm confirmed by CT had bilateral swelling of the lower extremities with pain radiating to the back. Radionuclide venography and pulmonary scintigraphy demonstrated occlusion of the inferior vena cava and multiple pulmonary emboli, with a hot spot in the liver. Surgery revealed a ruptured abdominal aortic aneurysm that occluded the inferior vena cava, fistula formation, and extensive thrombosis of the inferior vena cava proximal to the occlusion site. Radionuclide venography was useful in detecting venous obstruction and the collateral formation represented by the hot spot in the liver as complications of the ruptured abdominal aortic aneurysm, and in assessing the improvement of pulmonary embolism by medical therapy.

Aged↗
PubMed1995

Myocardial metabolism of 123I-BMIPP in patients with hypertrophic cardiomyopathy: assessment by radial long-axis SPET.

To elucidate the metabolism of free fatty acid in the myocardium of hypertrophic cardiomyopathy (HCM), SPET was performed with 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP), an analogue of free fatty acid, and with 201Tl in nine patients with HCM and eight healthy volunteers who acted as controls. For quantitative analysis of the apical area, a radial long-axis tomogram was reconstructed every 6 degrees after short-axis tomography. The relative regional uptake (RRU, %) in each segment was obtained by normalizing to the maximal value among all segments. The 3-h washout rate was calculated both for BMIPP and for 201Tl. The ratio of the RRU of BMIPP to that of 201Tl was significantly lower in the apical and antero-septal regions compared with other walls (P < 0.01) in the patients with HCM, whereas uptake of both BMIPP and 201Tl in the controls was homogeneous and there was a significant correlation between them. The coefficient of variation (CV) in all segments in the HCM patients was significantly higher (P < 0.01) than that of the controls both BMIPP and 201Tl, indicating inhomogeneous uptake of BMIPP in the HCM patients. The washout rate of BMIPP over 3 h was significantly higher in the patients with HCM (mean +/- S.D. 26.3 +/- 7.3%) than the controls (18.3 +/- 7.5%, P < 0.05). The ratio of segmental washout rate of BMIPP to that of 201Tl in the HCM patients was increased, especially in the septum and apex.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Usefulness of dipyridamole-thallium imaging in 257 patients with atherosclerotic vascular disease.

We evaluated the usefulness of dipyridamole-thallium imaging for the detection of ischaemic heart disease in 257 patients with atherosclerotic vascular disease (80 patients with arteriosclerosis obliterans, 81 patients with aneurysm of the abdominal aorta, 60 patients with aneurysm of the thoracic aorta and 36 patients with dissecting aortic aneurysm). Clinical evidence of ischaemic heart disease was found in 69 of 257 (27%) patients, including 32 patients with arteriosclerosis obliterans, 23 with aneurysm of the abdominal aorta, 9 with aneurysm of the thoracic aorta and 5 with dissecting aortic aneurysm. Dipyridamole-thallium imaging identified myocardial ischaemia in 49 of 69 (71%) patients with clinical evidence of ischaemic heart disease. Dipyridamole-thallium imaging showed positive results in 67 of 81 (83%) patients with aneurysm of the abdominal aorta. In patients with no clinical evidence of ischaemic heart disease, the results of dipyridamole-thallium imaging were positive in 39 of 188 (21%) patients. Dipyridamole-thallium imaging was positive in 90 of the 257 (35%) patients as a whole. When we combined the patients with positive dipyridamole-thallium imaging with those with negative dipyridamole-thallium imaging but who had clinical evidence of ischaemic heart disease, 42% of all patients had evidence of ischaemic heart disease. Our findings suggest that atherosclerotic vascular disease is strongly associated with ischaemic heart disease and that dipyridamole-thallium imaging is useful for the detection of ischaemic heart disease.

Aged↗
PubMed1995

Scintigraphic assessment of silent myocardial ischaemia after early infarction using myocardial SPET imaging with 201Tl and 123I-MIBG.

To test the hypothesis that myocardial sympathetic denervation reflects silent myocardial ischaemia early after infarction, 12 patients with myocardial infarction but without post-infarction angina pectoris underwent single photon emission tomography (SPET) at rest with 201Tl and 123I-metaiodobenzylguanidine (MIBG) shortly after and 3 months after infarction. Short-axis SPET images at the basal, mid-ventricular and apical portions of the left ventricle were selected, and each short-axis image was divided into eight segments. Tracer uptake in each of the 24 segments was scored using a 4-point scale. The total score in each segment was calculated as the defect score for each image, and the difference between the total defect score for the 201Tl and 123I-MIBG images was calculated as the delta defect score. All 12 patients underwent exercise stress 201Tl scintigraphy 1 month after infarction, and they were divided into two groups: those patients with (Group A, n = 7) and those patients without (Group B, n = 5) transient perfusion defects in the peri-infarcted region without chest pain. For the 123I-MIBG defect score, a marked reduction at 3 months was observed in Group A (24 +/- 12 vs 13 +/- 6; P < 0.01), whereas the defect score remained unchanged in Group B (25 +/- 7 vs 23 +/- 8; N.S.). The delta defect score was significantly reduced in Group A (10 +/- 5 vs 6 +/- 4; P < 0.05), whereas it remained unchanged in Group B. The 123I-MIBG defect score early after infarction was higher than the exercise-induced 201Tl defect score (24 +/- 12 vs 20 +/- 9; P < 0.01), whereas at 3 months post-infarction it was lower than the exercise-induced 201Tl defect score (13 +/- 6 vs 20 +/- 9; P < 0.05). Moreover, effort chest pain during daily activities was noted in 5 of the 7 (71%) patients in Group A within 3 months post-infarction. The results of this study suggest that viable but denervated myocardium (mismatched 123I-MIBG defects) is present in peri-infarcted regions, and that myocardial sensory nervous disturbance, which may co-exist with sympathetic nervous denervation, may induce silent myocardial ischaemia in patients with myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1995

Interleukin-12 augments the generation of autologous tumor-reactive CD8+ cytotoxic T lymphocytes from tumor-infiltrating lymphocytes.

Human tumor-infiltrating lymphocytes (TIL) were obtained from breast cancer, renal cancer or neuroblastoma to investigate the generation of autologous tumor-reactive CD8+ cytotoxic T lymphocytes (CTL). When TIL were cultured with interleukin (IL)-2 (100 U/ml), the growth of TIL peaked around 8-10 days after the initiation of culture. In contrast, the proliferation of TIL cultured with IL-2 plus IL-12 peaked around 4-5 days after culture and tumor cells rapidly disappeared from the culture. To determine the generation of autologous tumor-reactive CD8+ CTL, TIL-derived CD8+ T cells were separated by FACStar. Both IL-2-activated and IL-2 plus IL-12-activated TIL-CD8+ T cells showed the same level of lymphokine-activated killer activity against a variety of tumor cells. However, TIL-CD8+ T cells activated with IL-2 plus IL-12 revealed greatly augmented cytotoxicity against autologous tumor cells compared with that induced by IL-2 alone. The autologous tumor cell-killing activity of TIL-CD8+ CTL was significantly inhibited by the addition of F(ab)2 anti-CD3 monoclonal antibody, indicating that these CTL recognize autologous tumor antigen through T cell receptor. These results imply that IL-12 is a novel cytokine which facilitates the generation of autologous tumor-reactive CD8+ CTL from TIL.

CD8-Positive T-Lymphocytes↗
PubMed1995

Flow cytometric analysis of homologous restriction factor 20KD (HRF20) expression on progeny cells during differentiation from haemopoietic progenitors in paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder with a deficiency of glycosylphosphatidylinositol (GPI) anchored proteins. Homologous restriction factor 20KD (HRF20, CD59) is a GPI-anchored and major complement-regulatory protein which plays a key role in the haemolytic mechanism of PNH. We examined the differentiation stage at which the PNH abnormality occurs, by means of flow cytometric analysis of HRF20 expression. Non-phagocytic mononuclear marrow cells were labelled with anti-HRF20 monoclonal antibody and sorted into either HRF20-negative or -positive fractions. The sorted cells were cultured in methylcellulose and their progeny in the colonies or bursts were analysed for HRF20 expression. All colonies and bursts from HRF20-negative fractions remained negative, whereas those from HRF20-positive fractions were either positive or negative. The possibility of a sorting error was excluded, because the secondary colonies from the HRF20 positive primary colonies consisted of both positive and negative progeny. These results suggest that there are several stages during differentiation from early progenitors to mature cells, at which the PNH abnormality becomes manifest.

Blood Proteins↗
PubMed1995

Identification of two novel mutations in non-Jewish factor XI deficiency.

We have studied two heterozygous unrelated CRM- non-Jewish FXI-deficient patients. Neither of the patients carries a previously described mutation. Their FXI genes were screened by SSCP analysis following PCR amplification of each exon and the flanking intronic sequences. DNA fragments showing aberrant mobility were cloned and sequenced. The following mutations were identified: in case 1, a T to G transition in exon 12 results in the substitution of Phe-442 by Val (FXI-F442V); in case 2 a C to A transition in exon 5 results in the substitution of Cys-128 by a nonsense codon (FXI-C128X). The missense mutation results in a substitution within the protease domain of FXI. Molecular modelling locates this residue in a structurally conserved region of the protease domain and the amino acid substitution may therefore interfere with either chain folding and subsequent secretion or the stability of the protein in plasma. We conclude that the mutations which we have identified are responsible for the inherited abnormality in these patients.

Adult↗
PubMed1995

Familial risk factors for a second primary malignancy in endometrial or ovarian carcinoma.

OBJECTIVE: To elucidate the risk factor for a second primary carcinogenesis in endometrial or ovarian carcinoma patients. METHODS: Endometrial and ovarian carcinoma patients treated from 1975 through 1990 were analyzed clinicopathologically. RESULTS: The incidence of patients with a second primary malignancy was 10.5% (28/267) in endometrial carcinoma cases, and 9.0% (13/144) in ovarian carcinoma cases. Endometrial carcinoma patients whose parents, siblings, and/or children had developed malignant diseases were at risk for a second primary malignancy. This familial factor is also believed to be a risk factor for ovarian carcinoma patients, but the results lacked statistical significance. There also was no statistical significance with respect to smoking and/or alcohol consumption. More than one-half of the second primary carcinomas were breast, colon, or stomach carcinomas. CONCLUSIONS: Cancer patients with this familial high-risk factor should be carefully and regularly followed up by monitoring at every anatomic site, especially the breast, stomach, and colon, in order that the development of a second primary carcinoma can be detected as early as possible, and not be overlooked in examinations.

Endometrial Neoplasms↗
PubMed1995

Different susceptibilities of lymphokine-activated killer cells (LAK cells) among primary and metastatic renal cell carcinoma derived from the same patient.

OBJECTIVE: To investigate the susceptibility of primary renal cell carcinoma (RCC) and metastatic RCC to lymphokine-activated killer (LAK) cells using three RCC cell lines derived from the primary and metastatic tumours in a male patient with advanced RCC. MATERIALS AND METHODS: Three RCC cell lines (named HANKS) were derived from a 44-year-old man with advanced RCC. HANKS-Pr, HANKS-Lu and HANKS-LN were established from the primary lesion and the metastatic lung and lymph node lesions, respectively. The susceptibility of HANKS cell lines to 18 different LAK cells obtained from either patients with urological cancer or from healthy volunteers was studied. The three groups of LAK cells were divided as follows: (A) LAK cells from RCC patients (n = 6); (B) LAK cells from patients with transitional cell carcinoma (TCC)/prostatic carcinoma (CaP) (n = 4) and (C) healthy volunteers (n = 8). A 51Cr-releasing cytotoxic assay was used to determine susceptibility. RESULTS: The mean percentage lysis of the HANKS cell lines to the 18 allogenic LAK cells were 28.1% in HANKS-Pr, 20.2% in HANKS-Lu and 10.4% in HANKS-LN. The susceptibility of HANKS-LN to LAK cells was significantly lower than that of HANKS-Pr and HANKS-Lu in all three groups (P < 0.05). In contrast, the susceptibility of HANKS-Pr was significantly higher than HANKS-Lu in group A only (P < 0.01). CONCLUSION: This is the first report to describe the different susceptibilities of primary RCC and metastatic RCC derived from the same patient. HANKS-LN itself might be the least susceptible to LAK cells because it was not related to the source of LAK cells. Furthermore, RCC may affect the cytotoxicity of LAK cells to HANKS-Pr. These data indicate there are at least two different types of mechanisms leading to the different susceptibilities of HANKS cells to LAK cells.

Adult↗
PubMed1995

Electrophysiological studies on brainstem function in patients with myelomeningocele.

We investigated the brainstem auditory evoked potentials (BAEPs), somatosensory evoked potentials (SEPs), and electrically elicited blink reflexes (BRs) to evaluate the brainstem function in 31 patients with meyelomeningocele (MMC) including 22 with Chiari type-II malformation. The I-III interpeak latency (IPL) of the BAEPs and the N9-N13 IPL of the SEPs tended to become gradually prolonged from the normal range with increasing age. The III-V IPL of the BAEPs and the N13-N20 IPL of the SEPs were initially prolonged and decreased progressively to the normal range. These findings indicated a gradual latency shortening of the brainstem components and latency prolongation of the peripheral components. Thus, while primary brainstem dysfunction may improve with age, secondary dysfunction due to stretching and elongation of the lower cranial nerves and cervical nerve roots may intensify. The BRs showed an abnormal R2 in 90% of the cases, disclosing subclinical lesions in the medulla oblongata which were not detected by BAEPs alone. BAEPs, SEPs and BRs were combined to yield a functional evaluation of the brainstem and lower cranial nerves that could not be done by magnetic resonance imaging alone. No close relation was found between electrophysiological abnormalities and the degree of hindbrain anomaly by neuroimaging.

Adolescent↗
PubMed1995

Functional and anatomic evaluation of carotid atherothrombosis. A combined study of indium 111 platelet scintigraphy and B-mode ultrasonography.

We examined the relation between in vivo thrombogenicity and the morphology of carotid lesions to clarify the role of platelet deposition in carotid atherothrombosis. We evaluated 60 subjects (120 carotid bifurcations) who had at least one established risk factor for atherosclerosis by using indium 111 platelet scintigraphy and high-resolution B-mode ultrasonography. We evaluated platelet accumulation in the carotid arterial wall by means of a dual-tracer method that used In 111-labeled platelets and technetium 99m-labeled human serum albumin. The tracer accumulation was assessed both visually and semiquantitatively by using the platelet accumulation index, ie, the ratio of radioactivity of the amount of In 111-labeled platelets deposited on the vascular wall to the amount of radioactivity in labeled platelets circulating in the blood pool. The morphology of the carotid lesions was analyzed with B-mode ultrasonography in terms of the presence of ulceration, the maximum percent stenosis, the echogenicity of plaque, and the plaque score, which indicates the severity of systemic atherosclerosis. Platelet accumulation increased with increase in plaque score (P < .01), and the magnitude of platelet accumulation was significantly greater in lesions with ulceration than in those without (P < .05). The platelet accumulation index in vessels with plaque showed a very weak but significant correlation with maximum percent stenosis (r = .28, P < .05) and a stronger correlation with the unilateral plaque score (r = .42, P < .0001). Analysis of the echogenicity of plaque showed that heterogeneous plaque had a high frequency of accumulating platelets. Platelet accumulation was related to the surface characteristics and severity of carotid lesions, especially in the presence of ulceration.

Arteriosclerosis↗
PubMed1995

Effect of antimicrobial agents on chemotaxis of polymorphonuclear leukocytes.

The effect of antimicrobial agents on polymorphonuclear (PMN) chemotaxis was investigated. No significant effect was obtained in vitro with penicillins, cephems, macrolides, aminoglycosides or quinolones by the agarose plate method. However, chemotaxis was inhibited at 100 micrograms/ml or less of minocycline and doxycycline. The inhibitory effect on chemotaxis is considered to be due to chelation of Ca-ions by minocycline or doxycycline. The chelation reduced the concentrations of Ca-ions in the PMNs. The chemotactic index of minocycline increased when CaCl2 or A23187 were given in combination. Our findings indicate that a small number of the short lamellipodia were observed in PMNs preincubated with minocycline or doxycycline and these two agents affected the movement of PMNs morphologically.

Anti-Infective Agents↗
PubMed1995

[Inhibitory effects of hydroquinone-alpha-glucoside on melanin synthesis].

Inhibitory effects of hydroquinone-alpha-glucoside (HQ-alpha-G) on the melanogenesis were investigated and compared with those of arbutin. The levels of inhibitory effects of HQ-alpha-G and arbutin on the tyrosinase activity were nearly the same. Inhibitory effects of both compounds on the melanogenesis, were studied using cultured B16 melanoma cells, and HQ-alpha-G was also found to have a similar effect to that of arbutin without inhibiting cell growth. In this experiment, while HQ-alpha-G hardly inhibited cell growth at 1 mM, arbutin inhibit it significantly at the same concentration. From these results it is suggested that HQ-alpha-G as well as arbutin inhibited the melanogenesis by affecting tyrosinase rather than by killing melanocytes. Furthermore, the melanogenesis of guinea-pigs with brown hair was reduced to about 80% by applying them each compound. The great differences in toxicity to normal human keratinocyte were not recognized between these two glucosides. It is, therefore, considered that HQ-alpha-G is an effective and safe ingredient for cosmetics.

Animals↗