Biomedical subjects

M Mitani

Publications and source records attributed to M Mitani.

At least 55 records · Page 3Linked to original sources

PubMed1995

[Differential diagnosis of solitary pulmonary nodules by computerized statistical analysis using CT number].

There have been previous reports on the differentiation of benign pulmonary nodules from malignant ones using CT number. However, most of the nodules were without calcification, and diagnosis could be made only in limited cases. In the present study we established new multiple variables such as relative high density over the 75th percentile, inner gradient number (inner irregular rate), edge gradient number (edge irregular rate) and increased area rate (IAR). They are automatically calculated from CT data by computer. These variables are transformed into relative values, enabling comparisons of nodules without a standard reference phantom. With IAR, pulmonary nodules were classified into three types: type 1 (IAR 1.0-1.4), a high-density solid mass with well-defined margin; type 2 (IAR 1.4-2.0) between type 1 and type 3; and type 3 (IAR > 2.0) a low-density infiltrated mass with ill-defined margin. We studied 52 cases with solitary pulmonary nodules, whose diagnoses were confirmed either histologically or on follow-up. There were 34 benign nodules and 18 primary lung cancers. Using step-wise multiple regression with three variables, 42 of 52 cases were correctly diagnosed. Twenty-four of 28 type 1 cases and all 14 of type 2 cases were correctly diagnosed. This computer analysis is considered to be useful in distinguishing between benign and malignant solitary pulmonary nodules.

Aged↗

PubMed1995

[Chronic inflammatory demyelinating polyneuropathy associated with chronic liver disease due to type B and type C hepatitis virus].

A patient with chronic inflammatory demyelinating polyneuropathy (CIDP) associated with type B and type C hepatitis virus infection is reported. A 54-year-old female who had a blood transfusion at the age of 31 years was diagnosed as a carrier of hepatitis B virus at the age of 43. Liver dysfunction was first noted in 1987 and gradually grew worse year by year. Beginning in early June 1992, the patients general fatigue became worse, her serum GOT and GPT levels became elevated, and she complained of a tingling sensation in her arms and legs. Neurological examination revealed moderate sensory disturbance of the glove-and-stocking type in all of her extremities. Deep tendon reflexes were all diminished. Hepatitis C antibody was detected in the serum at this time. On June 12, 1993, progression of her sensory disturbance was found to be associated with generalized muscle weakness. Cerebrospinal fluid studies showed increased protein without pleocytosis. Motor nerve conduction studies revealed marked prolongation of terminal latencies, reduction of conduction velocities, and abnormal temporal dispersion of the motor potentials. No sensory potentials could be evoked at any of the sites stimulated. Sural nerve biopsy showed segmental demyelination and severe loss of large myelinated fibers as well as some onion bulb formation. A diagnosis of CIDP was made. Treatment with corticosteroids was started, but there was little improvement in neurological function. The liver dysfunction progressed further and ultimately the patient died of hepatic failure. An autopsy demonstrated liver cirrhosis, but no malignant tumors were evident.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗

PubMed1995

[MR angiography in intrathoracic masses: evaluation of the superior vena cava, its major branches and their relation to the mass].

MR angiography (MRA) of the thorax was evaluated in six healthy volunteers and 48 patients with an intrathoracic mass potentially infiltrating to the superior vena cava and/or its major branches. It was also compared with CT, spin echo MRI and X-ray venography. Three methods were used for MRA: sequential 2D-TOF MRA with presaturation band over the heart, 3D-MRA with bolus administration of Gd-DTPA in a single breath-hold and sequential 2D-TOF MRA with administration of Gd-DTPA. The major vessels themselves and their relation to the mass were clearly visualized on MRA in all volunteers and patients. Since original MRA demonstrated these vessels more clearly than projection MRA in our series, we considered that interpretation of MRA should be based mainly on original MRA. MRA generally could visualize the vessels as well as the other imaging modalities, and was sometimes superior to them. In conclusion, MRA is a non-invasive and effective method for the evaluation of major vessels and their relation to the mass in patients with an intrathoracic mass.

Adult↗

PubMed1994

Dysautonomia with acute sensory motor neuropathy. A new classification of acute autonomic neuropathy.

OBJECTIVES: To characterize the dysautonomia associated with acute sensory motor neuropathy and to discuss the classification of acute autonomic neuropathy. DESIGN: Case series. METHODS: Sympathetic skin response. Local sweat response to acetylcholine. Norepinephrine infusion test and acetylcholinesterase histochemistry of sural nerve biopsy specimens in addition to making conventional analyses of myelinated and unmyelinated fibers. RESULTS: In 12 patients with chronic neuropathy, acetylcholinesterase-positive fiber density and plantar sympathetic skin response size were well correlated, but in the two patients with acute autonomic sensory and motor neuropathy, there were discrepancies, acetylcholinesterase-positive fiber density being well preserved and sympathetic skin responses being absent. Histologic and electrophysiologic results indicated primary demyelination of the myelinated fibers. In contrast, previous studies of acute autonomic sensory and motor neuropathy reported dysfunction of the sympathetic postganglionic fibers and axonopathic change in myelinated fibers, poor recovery from dysautonomia. CONCLUSIONS: Dysautonomia with acute idiopathic neuropathy can be divided into two categories--postganglionic axonopathic and preganglionic demyelinating types of the sympathetic efferent pathways. The recovery from dysautonomia produced by the former lesion is poor, but recovery is better for that produced by the latter lesion.

Acetylcholine↗

PubMed1994

Consequence of diseases in aorta on evaluation of aortic regurgitation by aortic flow velocity profiles.

The aim of the study was to investigate whether flow velocity profiles of the aorta are related to the severity of aortic valve regurgitation (AR) in patients with diseases of the aorta. Aortic root angiography, abdominal aortic flow velocity measurements by pulsed Doppler method, and regurgitant jet measurements by color Doppler echocardiography were performed in 62 patients with various etiologies of AR and 13 patients without AR. The regurgitant fraction of abdominal aortic flow velocity profiles was related to the angiographic severity of AR except for the patients with Takayasu's arteritis and those after thoracic aorta grafting who showed large regurgitant fraction regardless of AR. Color Doppler evaluation was also correlated well with angiographic findings, but it was not possible in 13 of 62 patients with AR because of the inadequate color Doppler images. Although the observation of abdominal aortic flow profiles is clinically of value in noninvasive evaluation of AR, it could not be applied in patients with Takayasu's arteritis and those after graft surgery.

Adult↗

PubMed1994

[anorexia nervosa; an association with certain types of soft tissue emphysema].

A 17-year-old female with anorexia nervosa developed pneumomediastinum, subcutaneous emphysema, retroperitoneal emphysema, interstitial pulmonary emphysema and epidural emphysema (epidural emphysema; air between the dura mater and the vertebral arch). She had no history of bronchial asthma. The mechanism was presumed to be weakness of the alveolar wall due to malnutrition, leading to rupture of alveoli, followed by air entering the interstitium and dissecting along perivascular sheaths (interstitial pulmonary emphysema) into the mediastinum. A further increase in mediastinal pressure may bring about opening of the fascial planes along great vessels and allow air to penetrate into subcutaneous tissues and the spinal canal. These types of emphysema have been reported in bronchial asthma cases and in those on positive pressure breathing. To our knowledge, there are no previous reports of anorexia nervosa associated with these phenomena.

Adolescent↗

PubMed1994

[Acute encephalopathy with symmetrical lesions of the thalamus, the putamen and the cerebellum on magnetic resonance imaging].

A 19-year-old boy was admitted to our hospital because of impaired consciousness after experiencing fever and headaches for 7 days. The patient was in a deep coma or generalized convulsions, with retrocollis and decorticate posture. He never regained consciousness, remaining in an apallic state. The initial CSF pressure was 290 mm H2O, CSF cell count 18/3 mm3, protein 75 mg/100 ml, and sugar 74 mg/100 ml. There was no significant elevation in the viral titer in the serum or CSF. Plain CT on admission showed marked brain edema. MRI three months thereafter demonstrated symmetrical high intensity in the thalamus, the putamen and the cerebellum on both T1- and T2-weighted images, probably representing petechial bleeding. The lesions in the medial portion of the occipital lobes showed iso intensity on T1-weighted images and high intensity on T2-weighted images. These lesions were consistent with infarction of both posterior cerebral arteries, which may have been due to severe brain edema. The clinical and MRI findings were similar to those of patients with acute encephalopathy with low-density areas in the thalamus or bilateral striatal necrosis in childhood. To the best of our knowledge, there have been no reports of cases like ours in adults.

Acute Disease↗

PubMed1993

[Percutaneous transhepatic gastrostomy with CT guidance in patients with partial gastrectomy].

Percutaneous transhepatic gastrostomy was performed in two patients, one with partial gastrectomy and Billroth I anastomosis and one with esophageal reconstruction with subtotal stomach, in whom oral feeding was precluded. In both patients, percutaneous gastrostomy with fluoroscopic guidance was impossible since the gastric remnants were small, had a high subcostal position, and were overlain by the transverse colon, lung and left lobe of the liver. The only route available to avoid the overlying bowel and lung was the transhepatic approach. The gastric remnants were punctured with a 22-gauge PTC needle through the left lobe of the liver with CT guidance, and an 8 Fr. Cope-type catheter was fluoroscopically placed in the gastric remnant or the duodenum after tract dilatation over the guide wire. No complications occurred during or after the procedures, and the condition of both patients was greatly improved. Although gastrostomy in patients with partial gastrectomy is thought to be very difficult, percutaneous transhepatic gastrostomy with CT guidance is easy and may be safe since adhesion between the liver and gastric remnant can prevent massive hemorrhage or displacement of the catheters.

Aged↗

PubMed1992

[MR angiography of the lung using 3-dimensional imaging method].

Three-Dimensional MR angiography (3D-MRA) of the lung was performed in 5 healthy volunteers and 14 patients with primary pulmonary cancer in the hilum, and compared with 2D-MRA. As 3D-MRA could be obtained with single breath holding after intravenous bolus injection of Gd-DTPA, pulmonary vessels of the hilum and peripheral zone were demonstrated more definitely than those of 2D-MRA. In all patients except one case, the relation between the tumor and pulmonary vessels was visualized more clearly by 3D-MRA than 2D-MRA. This technique is considered a non-invasive and effective method for evaluation of pulmonary vessels in the patient with hilar tumor.

Humans↗

PubMed1992

[Hepatic arteriography under temporary hepatic venous occlusion].

Hepatic arteriography with and without temporary segmental hepatic vein occlusion was performed in 10 patients, five of whom had chronic liver injury. Hepatic arteriograms obtained during hepatic venous obstruction demonstrated significantly more peripheral and definite arterial branches in the occluded area and fewer peripheral branches in the non-occluded segment. A prolonged, dense hepatogram (sinusoidogram) showing hepatofugal opacification of the portal vein was obtained in the occluded area. Only one case with a large veno-venous anastomosis did not show these findings. Hepatic arteriograms in two cases with hepatocellular carcinoma provided clear visualization of peripheral portal branches that could act as efferent tumor vessels during regional temporary hepatic vein occlusion. Temporary hepatic venous occlusion may cause a sudden increase of hepatic arterial flow in the occluded area and transsinusoidal arterioportal communication there. This method can be useful for the diagnosis and arterial infusion or embolization therapy of hepatic diseases.

Adult↗

PubMed1992

[Clinical experience of continuous retrograde cerebral perfusion for assisted circulation during the surgical treatment of acute dissection of aorta: Stanford A type].

Surgical treatment of the dissection involving the ascending aorta or aortic arch represents one of the most complicated technical challenges. Recently continuous retrograde cerebral perfusion (CRCP) is sometimes applied in order to avoid cerebral complications. We compared two surgical groups, one of which was performed graft-replacement of ascending aorta using CRCP and another was utilized normograde cerebral circulation, about the technique of operation, total extracorporeal circulation (ECC) time, aortic clamp time, separate ECC time, total bleeding volume, and urination during operation. In the group using CRCP, separate ECC time was 53 min (mean), and intraoperative bleeding volume was only 1,170 ml. Good urination was obtained during operation. Postoperative courses were uneventful, and consciousness was smoothly and soon recovered. The new method of separate ECC has some advantages over the previously described methods, particularly for avoidance of cerebral complications. As it is not necessary to require dissecting, taping, and clamping of cephalic branches, operative procedure will be very simplified, easier and safer, leading to intraoperative bleeding is a fewer. It is our belief that this method should be widely applied in the operation of graft-replacement of ascending aorta or aortic arch in the near future.

Aged↗

PubMed1991

Specific association of retroviral envelope protein, p15E, with human cell surfaces.

Experiments were carried out to analyze the binding sites on human cells for highly purified retroviral protein p15E isolated from Feline Leukemia Virus, Rickard Strain. Binding of 125I-labeled p15E was tested with surfaces of human peripheral blood lymphocytes and 3 cell lines, Raji, MOLT-4, and U-937. 125I-labeled p15E showed specific binding to human peripheral blood lymphocytes. In addition, all of the cell lines tested showed binding of 125I-labeled p15E. Using U-937 cells, we characterized the interaction between p15E and the surface of these cells, and showed that the binding was specific by the following 3 different sets of evidence: (i) in equilibrium binding experiments, 18,000 binding sites with a dissociation constant of 2 x 10(-9) M were present on U-937 cells; (ii) trypsin or N-glycanase treatment decreased the binding sites of 125I-labeled p15E; and (iii) by affinity chromatography using p15E or BSA Sepharose columns, the isolated membranes of 125I-labeled U-937 cells previously treated with Triton X-100 showed a significantly higher binding to the p15E column than to the BSA column.

Amidohydrolases↗

PubMed1991

Application of Doppler color flow imaging to determine valve area in mitral stenosis.

This study was undertaken to examine whether Doppler color flow imaging could accurately estimate the valve area in mitral stenosis. Doppler color flow assessments were performed in both an in vitro model and in 30 patients with mitral stenosis undergoing cardiac catheterization. In the experimental Doppler study using a circuit model, color jet width correlated well with actual orifice diameter (r = 0.99). In the clinical Doppler study, the mitral valve orifice was assumed to be elliptic and the mitral valve area was calculated from the following equation: (pi/4) (a x b), where a = color jet width at the mitral valve orifice in the apical long-axis view (short diameter) and b = the width in the 90 degrees rotated view (long diameter). Mitral valve area was also determined by two-dimensional echocardiography and the pressure half-time method, and the results for all three noninvasive methods were compared with those obtained at cardiac catheterization. By Doppler color flow imaging, mitral valve area could be determined in all patients and there was a significant correlation between the Doppler jet and catheterization estimates of mitral valve area (r = 0.93). Valve area determined by two-dimensional echocardiography correlated well with catheterization measurements in 26 patients (r = 0.84). However, the area could not be determined in 4 (13%) of the 30 patients because of technical problems. Although there was a fair correlation between the valve area determined by the pressure half-time method and catheterization (r = 0.79), this method tended to overestimate valve area in patients with aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗

PubMed1991

Intracardiac mobile thrombus and D-dimer fragment of fibrin in patients with mitral stenosis.

OBJECTIVE: To investigate the relation between intracardiac thrombus and blood coagulability in patients with mitral stenosis. DESIGN: Prospective study. Cross sectional echocardiography and plasma concentrations of the D-dimer fragment of fibrin were used concurrently to detect intracardiac thrombus in patients with mitral stenosis. SETTING: Department of Medicine, National Cardiovascular Centre, Osaka, Japan. PATIENTS: 63 patients with mitral stenosis. None of them had been receiving any anticoagulants or antiplatelet agents. MAIN OUTCOME MEASURES: Plasma concentrations of D-dimer in patients with a mobile intracardiac thrombus, those in patients with a non-mobile intracardiac thrombus, and those in patients without an intracardiac thrombus. RESULTS: A mobile intracardiac thrombus was found in 10 patients and a non-mobile thrombus in eight. The remaining 45 patients had no intracardiac thrombi. Plasma concentrations of D-dimer in the 10 patients with a mobile thrombus were all greater than 300 ng/ml (mean 983.3, 95% confidence interval 498.9 to 1467.7 ng/ml) and they were significantly higher than those in the patients with a non-mobile thrombus (226.2, 33.6 to 418.8 ng/ml) and the patients without an intracardiac thrombus (147.2, 110.4 to 184 ng/ml). CONCLUSIONS: A high plasma concentration of D-dimer seemed to reflect a hypercoagulable intracardiac state and may be a helpful indicator of the possible presence of mobile intracardiac thrombus in patients with mitral stenosis.

Antifibrinolytic Agents↗

PubMed1991

Detection of human factor B biosynthesis in culture supernatants and cell lysates by ELISA.

We report here on the development of a simple, sensitive, convenient, and quantitative enzyme-linked immunosorbent assay for human factor B, a protein of the alternative complement pathway, by the sandwich method using goat anti-human factor B antibody. The assay described herein is reproducible and highly specific for human factor B. The assay was used to determine biosynthesis (cell lysates or extracts) and secretion (supernatants) of human factor B using human monocyte cell line U937. Phorbol myristate acetate strongly enhanced (10- to 20-fold) biosynthesis of factor B by U937. The combination of a sensitive enzyme-linked immunosorbent assay and phorbol myristate acetate enabled us to use a microculture system.

Antimetabolites↗

PubMed1991

[A case of liver cirrhosis associated with chronic subdural hematoma and hepatic encephalopathy].

A 58-year-old male liver cirrhosis patient, who had a history of recurrent hepatic encephalopathy, was admitted to our hospital because of clouding of consciousness. He had an episode of recent head trauma. On admission, he was drowsy and exhibited flapping tremor, fetor hepaticus and ascites. Laboratory data showed an increase in blood ammonia level, and a decrease in peripheral thrombocytes, serum albumin and prothrombin value. A ratio of branched-chain to aromatic amino acids was reduced. Antibody against hepatitis C virus was positive. His electroencephalogram showed bilaterally large synchronous slow waves. He was treated with intravenous branched-chain amino acids, and recovered. Cranial computed tomography on day 9 demonstrated a crescent shaped area of low density in the right frontotempoparietal subdural region. He was diagnosed as chronic subdural hematoma, which was treated surgically. It has been suggested that chronic subdural hematomas develop as a complication of hemostatic deficiency due to liver cirrhosis.

Chronic Disease↗

PubMed1991

The suppressive effect of a synthetic retroviral peptide on the human IFN gamma production is abrogated by the combined stimulation with IL-1 and IL-2.

Certain retroviral envelope proteins and peptides have been shown to be highly immunosuppressive. Recently, we have demonstrated that a synthetic 17 amino acid peptide (CKS-17*) homologous to a highly conserved region in the transmembrane portion of the envelope of several human or animal retroviruses suppresses the production of human interferon-gamma (IFN gamma) by human peripheral blood leukocytes (PBL). In the present investigation, we studied the role of exogenous IL-1 or IL-2, and IL-1 plus IL-2 on the suppressive action of CKS-17* in the production of IFN gamma. The results showed that preculture of PBL with CKS-17* reduced the production of IFN gamma in a dose-dependent manner. The addition of IL-1 or IL-2 reduced, in part, this suppression of IFN gamma production. Full abrogation of the inhibition attributable to CKS-17, however, occurred only when PBL precultured with CKS-17* were recultured with staphylococcus enterotoxin A (SEA) together with exogenous IL-1 plus IL-2. These results show that the inhibition of IFN-gamma production by CKS-17* is reversible. The findings indicate that cytokines can modulate certain of the immunosuppressive actions attributable to retroviruses or their components and suggest that some cytokines influence immunosuppressive consequences of retroviral infection.

Cells, Cultured↗

PubMed1990

Inhibition of murine cytotoxic T lymphocyte activity by a synthetic retroviral peptide and abrogation of this activity by IL.

A synthetic 17 amino acid peptide (CKS-17) homologous to a highly conserved region of human and animal retroviral transmembrane proteins was investigated for its influence on the generation of murine alloantigen-specific CTL activity in vitro. CKS-17 coupled to a carrier protein, BSA or human serum albumin, inhibited the generation of anti-allo CTL in a dose-dependent manner. Controls consisting of BSA and human serum albumin, which had undergone the coupling procedure or neurotensin, an unrelated peptide, coupled to BSA in an identical manner as CKS-17 showed no such inhibitory action. The suppression was not restricted to the Ag specificity of the CTL activity. CKS-17 exerted inhibitory effects on the early afferent phase of CTL induction. Kinetic studies showed that the suppressive activity occurred when CKS-17 was introduced to the immunologically stimulating culture concomitant with or up to 48 h after initiation of culture. Analysis of the frequency of CTL precursor cells using limiting-dilution assays revealed that CKS-17 did act to reduce the number of precursor cells. Abrogation of the inhibition of CTL activity was observed when IL-2 was introduced to the culture together with the stimulator cells. Other lymphokines, such as IL-4, exerted a similar influence to counteract this suppression.

Animals↗