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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 919 records · Page 51Linked to original sources
PubMed1994

Detection of myocardial ischemia by 31P magnetic resonance spectroscopy during handgrip exercise.

BACKGROUND: The metabolic changes of myocardial ischemia in patients with coronary artery disease assessed by 31P magnetic resonance spectroscopy (MRS) have been reported previously. A significant decrease in the ratio of phosphocreatine (PCr) to ATP during handgrip exercise in a group of patients with severe coronary artery disease has been demonstrated. However, there are no reports at present that directly compare cardiac 31P MRS data with exercise 201Tl myocardial scintigraphy, now established as one of the most important clinical methods to assess myocardial ischemia. The purpose of this study was to investigate whether 31P MRS with handgrip exercise testing is able to detect myocardial ischemia, demonstrated by exercise 201Tl scintigraphy. METHODS AND RESULTS: Twenty-seven patients with severe stenosis of the left anterior descending coronary artery (> or = 75%) and 11 normal control subjects composed the present study. Patients were divided into two groups on the basis of exercise 201Tl scintigraphy: a reversible 201Tl defect group (RD[+]) who demonstrated redistribution at the late image and a fixed 201Tl defect group (RD[-]). While lying supine within the magnet, subjects performed handgrip exercise at 30% of maximal force once in every two cardiac cycles. 31P MR spectra were collected before and during handgrip exercise. Data were corrected for the saturation factor. ANOVA revealed significant differences among the three groups with respect to the mean +/- SD PCr/ATP ratio at rest (control, 1.85 +/- 0.28 > RD(+), 1.60 +/- 0.19 > RD(-), 1.24 +/- 0.30; P < .05). The PCr/ATP ratio decreased significantly from 1.60 +/- 0.19 at rest to 0.96 +/- 0.28 during exercise (P < .001) in the RD(+) group (n = 15). However, in the RD(-) group (n = 12), the ratio did not change significantly during handgrip exercise (1.24 +/- 0.30 at rest versus 1.19 +/- 0.28 during exercise). Similarly, the ratio did not change in the control group (n = 11) (1.85 +/- 0.28 at rest versus 1.90 +/- 0.23 during exercise). CONCLUSIONS: Contrary to normal subjects or patients with fixed thallium defects, the PCr/ATP ratio was significantly altered by exercise in patients with reversible thallium defects. These results suggest that 31P MRS with handgrip exercise testing is a sensitive method for detecting myocardial ischemia.

Adenosine Triphosphate↗
PubMed1994

Development of a sensitive two-site immunoradiometric assay for parathyroid hormone-related peptide: evidence for elevated levels in plasma from patients with adult T-cell leukemia/lymphoma and B-cell lymphoma.

We have developed a sensitive immunoradiometric assay for PTH-related peptide (PTHrP) using a monoclonal antibody against PTHrP(1-34) and a polyclonal antibody against PTHrP(50-83), with recombinant human PTHrP(1-87) as the standard. The detection limit of the immunoradiometric assay was 0.5 pmol/L, and plasma PTHrP(1-87) concentrations in 110 healthy subjects were 0.8 +/- 0.01 pmol/L, with the upper limit of the normal range being 1.1 pmol/L. Increased circulating PTHrP(1-87) concentrations were demonstrated in all 46 cancer patients with hypercalcemia, but not in patients with primary hyperparathyroidism, chronic renal failure, or hypoparathyroidism. Normalization of serum calcium levels after resection of tumors was shown to correlate well with that of plasma PTHrP(1-87) concentrations in 2 cancer patients. High circulating PTHrP(1-87) levels were also demonstrated in 12 out of 13 hypercalcemic patients with adult T-cell leukemia/lymphoma and in 7 out of 8 hypercalcemic patients with non-Hodgkin's lymphoma especially of B-cell type. These results suggest that PTHrP is a major humoral factor responsible for the hypercalcemia frequently associated with adult T-cell leukemia/lymphoma and also with B-cell lymphoma.

Adult↗
PubMed1994

Determination of end-tidal sevoflurane concentration for tracheal intubation and minimum alveolar anesthetic concentration in adults.

The purpose of this study was to determine both the concentration of sevoflurane required for tracheal intubation (MACEI) and its minimum alveolar anesthetic concentration (MAC) in adults. The study group consisted of 86 elective surgical patients, ASA physical status I or II, aged 16-59 yr. There was no premedication administered. For MACEI determination, after establishing and maintaining the predetermined end-tidal concentration for 20 min, tracheal intubation was attempted using a cuffed tracheal tube without muscle relaxant or other adjuvants. Each concentration at which tracheal intubation was attempted was predetermined as follows: 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, and 7.0%. For MAC determination, the patients examined were basically the same as those for MACEI determination, except for those who received muscle relaxant or other adjuvants because they were "not intubated smoothly." After establishing and maintaining the predetermined end-tidal concentration for 20 min, skin incision was attempted. Each concentration at which skin incision was attempted was predetermined as follows: 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%. The MACEI of sevoflurane was 4.52% (95% confidence limits, 3.91%-5.21%), and the ED95 for tracheal intubation was 8.07%. The MAC of sevoflurane was 1.58% (95% confidence limits, 1.14%-1.98%), and the AD95 (anesthetic ED95) was 2.96%. The MACEI/MAC ratio was 2.86 (95% confidence limits, 2.63-3.43). Anesthesia induction followed by tracheal intubation can be accomplished in adults when sevoflurane is administered as a sole anesthetic, but in excess of 8% end-tidal concentration.

Adolescent↗
PubMed1994

Studies on active substances in herbs used for hair treatment. I. Effects of herb extracts on hair growth and isolation of an active substance from Polyporus umbellatus F.

The effects of methanol extracts of 80 herbs on hair growth were investigated, using normal C3H/He mice from which telogen hair on the back had been removed. Eighteen of the extracts apparently promoted hair regrowth on the mice. As one of active principles in Polyporus umbellatus F., 3,4-dihydroxybenzaldehyde was isolated by column chromatography on Amberlite XAD-2, Sephadex LH-20 and silica gel.

Animals↗
PubMed1994

Replication of virulent and attenuated strains of Aujeszky's disease virus in swine alveolar macrophages.

In vitro and in vivo replication of Aujeszky's disease virus (ADV) in swine alveolar macrophages (AM) was studied using two virulent strains and a vaccine strain with deletions in the thymidine kinase and gIII genes. In vitro, AM were highly permissive to virulent ADV infection. Virus progeny titers of virulent strains in the cell phase and in the fluid phase were higher than 10(7.3) TCID50/ml at 84 hr post-inoculation (PI). For vaccine strain infection, AM were less permissive, yielding virus titers of 10(2.3) TCID50/ml at 84 hr PI. To study in vivo replication of ADV in AM, virus isolations were made from AM collected at intervals from pigs inoculated intranasally with both the virulent and vaccine strains. Virus was isolated from AM samples collected from all pigs infected with the virulent strain from days 2 to 22 PI. On the contrary, no virus was detected in AM samples collected from pigs infected with the vaccine strain. The results presented suggested that in vivo virulent ADV replicates for a relatively long period in swine alveolar macrophages.

Animals↗
PubMed1994

Simultaneous occurrence of three primary lung cancers.

We present a patient with three lung cancers composed of adenosquamous carcinoma, adenocarcinoma, and squamous cell carcinoma. Marked response was obtained in squamous cell carcinoma components following chemotherapy, but not in adenocarcinoma components. Even multiple malignant lesions of the lung might have a chance to be controlled by a combination of chemotherapy and surgery.

Adenocarcinoma↗
PubMed1994

Histochemistry and immunohistochemistry of extracellular matrix of rat fetal Ductus arteriosus during the indomethacin-induced constriction.

Administration of anti-inflammatory non-steroidal drugs to pregnant animals causes constriction of the fetal ductus arteriosus (DA). To clarify the mechanism of the indomethacin-induced constriction of the rat fetal DA, extracellular matrix (ECM) components were observed by immunohistochemical techniques with antibodies 2B1, 6B6, 3B3, 9A2 and others to various kinds of proteoglycans (PGs). In the 10mg/kg group, the large PG revealed with antibody 2B1 was increased in the inner and outer media at constriction, and chondroitin 6-sulfate PG was strongly immunostained with antibody 3B3 as granular substances in the outer media, although no difference in stainability of chondroitin 4-sulfate PG revealed with the antibody 9A2 was observed between experimental and control groups. This suggests that the cells composing the fetal DA showed a tendency of proliferation and resultant production and aggregation of large PG with chondroitin 6-sulfate chains during constriction induced by indomethacin-treatment.

Animals↗
PubMed1994

Adrenogenital syndrome caused by an androgen-producing adrenocortical tumor.

We describe here a typical case of virilizing adrenocortical tumor. A 23-year-old Japanese woman had her male-like musculature, hirsutism, the absence of breast development and marked clitoromegaly. Adrenal androgens were remarkably elevated, with plasma dehydroepiandrosterone sulfate 2,752 micrograms/dl, plasma testosterone 250 ng/dl and urinary 17-ketosteroids 203.4 mg/day. A well-encapsulated tumor approximately 7 cm in diameter was detected in the left adrenal gland by computed tomography, magnetic resonance imaging and arteriography. The tumor was surgically resected and histologically diagnosed as a benign adrenocortical adenoma. The elevated adrenal androgens returned to normal postoperatively with amelioration of her masculinized clinical features.

Adenoma↗
PubMed1994

Identification of major tyrosine-phosphorylated proteins in Csk-deficient cells.

Csk is a non-receptor protein-tyrosine kinase that acts as a negative regulator of Src family tyrosine kinases. Csk-deficient mouse embryos exhibited developmental defects including inability to turn and impaired formation of neural tube. In these embryos, an accumulation of tyrosine phosphorylated proteins was observed as a consequence of constitutive activation of Src family kinases. In order to identify those tyrosine phosphorylated proteins, we established a Csk-deficient cell line from embryos lacking both Csk and the anti-oncogene product p53. On surveying several proteins known as Src substrates, we found that phosphorylation level of p80/85 (cortactin) was markedly elevated in the Csk-deficient cells. Enhancement of cortactin phosphorylation was also seen in Csk-deficient embryos. Furthermore, immunoprecipitated Src was able to directly phosphorylate cortactin in vitro. Thus, we suggest that cortactin is a good substrate of activated Src family kinases in vivo and may play important roles in signaling pathways mediated by Src family kinases.

Animals↗
PubMed1994

Localization of mitochondrial large rRNA in germinal granules and the consequent segregation of germ line.

This article reviews recent studies on cytoplasmic factors for germ-line establishment in Drosophila and Xenopus. In a variety of animal groups, the cytoplasmic factors for germ-line differentiation have been postulated to be localized in the germ plasm. We have found that mitochondrial large rRNA (mtlrRNA) is present in germinal granules, the distinctive morphological markers of germ plasm in the fruit-fly and the frog. MtlrRNA has been identified as a cytoplasmic factor that induce pole cells, the progenitor of the germ line, in uv-sterilized Drosophila embryos. The developmental stages of Xenopus at which mtlrRNA is present in germinal granules correspond to the stages of germ line segregation. Based on our findings and available data on posterior class gene products as well as on classical developmental biology of germ cells, we discuss the probable role of mtlrRNA in germ-line segregation from the somatic line in these animals.

Animals↗
PubMed1994

[A new index of disease activity in Crohn's disease].

A comprehensive assessment including subjective and objective parameters seems to be essential for evaluation of disease activity in Crohn's disease. The aim of the present study was to develop an activity index (AI) of Crohn's disease, composed of both subjective and objective variables. Data composed of a total 132 clinical examinations in 100 patients with Crohn's disease were used to determine the AI. Three physicians independently evaluated disease severity in each patient. Stepwise multiple regression analysis was carried out with the overall evaluation as a dependent variable, and with 18 parameters as independent variables. Analysis showed that the following seven variables had a significant correlation with physician's overall evaluation: abdominal pain, abdominal tenderness, complications, C-reactive protein (CRP), body temperature, diarrhea, and body mass index (BMI). AI was expressed as follows: AI = 3.5 x abdominal pain + 3 x abdominal tenderness + 3 x complications + CRP + 3 x body temperature + 4 x diarrhea - 0.4 x BMI. AI values below 15 corresponded to inactive disease, values between 15 and 25 to mild disease, values between 25 and 35 to moderate disease, and values above 35 to severe disease. This study suggests that the activity index is useful for evaluation of the effect of medical treatment in Crohn's disease.

Adult↗
PubMed1994

[A case of right atrial thrombus associated with idiopathic pericarditis].

A 73-year-old man suffering from exertional dyspnea was admitted to our hospital. Transthoracic echocardiography revealed pericardial effusion. This case was diagnosed as idiopathic pericarditis from laboratory data and pathological findings of the pericardial biopsy. A right atrial mass was detected by computed tomography, transesophageal echocardiography and MRI during conservative treatment. Because of the risk of pulmonary embolism due to the presence of the right atrial mass, removal of the mass was performed. The atrial mass was diagnosed as organized thrombus by pathological examination. It was suggested that the cause of right atrial thrombus was congestion and damage of the right atrial endocardium due to idiopathic pericarditis and atrial fibrillation. This case of a right atrial thrombus associated with idiopathic pericarditis is very rare, and MRI was proven to be very useful in the differentiation of a thrombus from cardiac tumor.

Aged↗
PubMed1994

[Effects of carbamazepine and zonisamide on dopaminergic system in rat striatum and hippocampus].

The effects of zonisamide and carbamazepine on extracellular and intraneuronal levels of monoamine, its precursor and metabolites were determined in rat striatum and hippocampus. DA re-uptake and monoamine oxidase activities were also determined. Acute administrations of therapeutic doses of zonisamide and carbamazepine increased the extracellular and intraneuronal levels of monoamine, however, supratherapeutic doses of zonisamide and carbamazepine decreased extra- and intracellular monoamine levels. Chronic administrations of therapeutic doses of zonisamide and carbamazepine increased intraneuronal levels of monoamine, while supratherapeutic doses of zonisamide and carbamazepine decreased. Monoamine oxidase type B activity was inhibited by zonisamide, and the IC50 values of inhibition by zonisamide for type B monoamine oxidase were 660 microM, however, carbamazepine did not affect monoamine oxidase activity. Zonisamide and carbamazepine showed no effect on monoamine re-uptake within therapeutically relevant concentrations. These results suggest that therapeutic doses of zonisamide and carbamazepine enhance monoamine turnover, while supratherapeutic doses of zonisamide and carbamazepine inhibit monoamine turnover. Those effects of zonisamide and carbamazepine on monoamine metabolism are at least partly involved in the mechanisms of action of zonisamide and carbamazepine.

Animals↗
PubMed1994

[A case of pulmonary malignant lymphoma associated with localized amyloid plaque].

A 51-year-old woman admitted to our hospital. Chest X-ray film showed infiltrations in left S4 region, which had been pointed out since two years before. On exploratory thoracotomy, lingual segmentectomy was performed because no metastatic lesions were found in the mediastinal and hilar lymph nodes. Pathological and immunohistological examinations revealed findings corresponding to pulmonary malignant lymphoma (diffuse, small cell type, B cell) with amyloid plaque. The patient is doing well 20 months after operation without any signs of recurrence. The clinical and histological findings of this case may suggest a close relationship between malignant lymphoma and production of amyloid.

Amyloidosis↗
PubMed1994

[Anesthetic management of a patient with Freeman-Sheldon syndrome].

The Freeman-Sheldon syndrome is a rare congenital myopathy and dysplasia that results in deformity of the face, hands, and feet. We describe here some problems in general anesthesia from the anesthetic management point of view. An 8-year-old girl with Freeman-Sheldon syndrome underwent surgery under general anesthesia for the correction of lip deformity and microstomia. Patients with this syndrome may present anesthetic problems involving difficulties in endotracheal intubation due to microstomia, micrognathia and neck rigidity, as well as postoperative respiratory complications and problems that relate to myogenetic morphology and myofunctional abnormalities. Preoperatively, we analyzed X-ray cephalograms to evaluate the difficulty of endotracheal intubation. Fiberscopic endotracheal intubation was performed; the time required was 55 minutes. On recovery from anesthesia and after becoming fully responsive, she was extubated in the operating room without any complications. Postoperative recovery was uneventful. Patients with Freeman-Sheldon syndrome should be managed by good preanesthetic preparation, and attention should be paid to postoperative respiratory complications due to the use of muscle relaxants and to securing intravenous access.

Abnormalities, Multiple↗
PubMed1994

[Multiple myeloma with massive ascites fluid--immunophenotypic analysis of myeloma cell and its IL-6-dependent growth].

A 75-year-old female was diagnosed as having multiple myeloma (IgG.lambda type. Stage IIA) with plasmacytoma of the head and back in October, 1989. She obtained partial remission by MCNU and MP therapy, but relapsed with massive ascites in January, 1991. VAD therapy was not effective and she died of multiple organ failure on February 23. Her ascites contained a large number of myeloma cells, and the phenotypic analysis and the response to interleukin-6 (IL-6) of these myeloma cells were examined. The myeloma cells were positive for CD33, CD45, CD45RA, CD63, CD71, plasma cell associated antigens such as CD38, PCA-1, BL3, and various kinds of adhesion molecules: CD11a/CD18 (LFA-1), CD29 (VLA-beta 1), CD44 (H-CAM), CD49d (VLA-4), CD54 (ICAM-1), CD56 (N-CAM), CD58 (LFA-3). IL-6 level in the ascites was increased at 91.0pg/ml. The myeloma cells showed an IL-6 dependent growth, which was inhibited by anti-IL-6 antibody (Ab) and anti-IL-6 receptor Ab in vitro. Myeloma cells appearing in ascites have rarely been reported. Our case suggested that IL-6 was a potent growth factor of myeloma cells through an autocrine mechanism in the ascites, and resulted in an aggressive myeloma.

Aged↗