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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 667 records · Page 37Linked to original sources
PubMed1994

Proton magnetic resonance spectroscopy of cerebrospinal fluid as an aid in neurological diagnosis.

The proton magnetic resonance (1H-NMR) spectra were obtained from 38 cerebrospinal fluid (CSF) samples from 34 patients with various central nervous system (CNS) diseases and the H2O signals were reduced by the presaturation method. A doublet signal for CH3 protons of lactate, as well as a singlet one for alpha-CH proton of glucose, were clearly detected in all the spectra obtained. The relative lactate concentration values were calculated on the basis of the glucose concentrations which had been measured by a routine laboratory method in the hospital and the ratios of the peak heights (lactate CH3/glucose alpha-CH). In the CSF samples examined, the relative lactate values semi-quantitatively determined in this way were clearly elevated in cerebral infarction and bacterial meningitis, but not in other disorders including viral meningitis. On the other hand, one CSF component whose enhancement was found only in a sample from a hepatic encephalitis patient was identified as glutamine from the double quantum filtered-shift correlation spectrum. These results suggest that 1H-NMR spectroscopy of CSF can become a powerful aid in biochemical diagnosis of CNS diseases.

Adult↗
PubMed1994

The induction of interleukin-6 (IL-6) and colony-stimulating factors (CSFs) by FK565 and its thrombopoietic activity following in vivo administration.

The induction of macrophage colony-stimulating factor (M-CSF) in monkey plasma following administration of FK565 was observed within 2 h of injection peaked at 4 h, and remained high after 24 h. Interleukin-6 (IL-6) and M-CSF levels increased in monkeys treated with FK565, even at doses as low as 0.01 mg/kg. Granulocyte CSF (G-CSF) levels increased slightly following a dose of 1 mg/kg, but granulocyte macrophage CSF (GM-CSF) was not detected at any doses of FK565 studied. To examine the thrombopoietic activity of FK565 in vivo, single doses of drug (0.01, 0.1 or 1.0 mg/kg) were administered i.v. to cynomolgus monkeys or normal mice on day 0. The promotes platelet (PLT) count after FK565 injection decreased transiently on days 1 and 2, and then increased in a dose-dependent manner on day 5 and was still high on day 14. The experiment using anti-PLT antibody showed that the increased PLT count was not simply due to a rebound phenomenon after the transient decrease in PLT. The effect of i.v. FK565 was studied in mice myelosuppressed with a single dose of mitomycin C (MMC) (5.6 mg/kg). The fall in PLT count was suppressed on day 7 by 0.1 and 1.0 mg/kg FK565. Although intact cells or tissues are necessary for an increase in PLT following FK565 treatment, FK565 suppressed the impaired hematopoietic function seen after chemotherapy. FK565 is proposed as a drug to restore reduced neutrophil and platelet counts found in AIDS or cancer therapy.

Animals↗
PubMed1994

Amino acids and peptides. XXII. Preparation and antinociceptive effect of [D-Ala2]Leu-enkephalin-poly(ethylene glycol) hybrid.

The hybrid of poly(ethylene glycol) and [D-Ala2]Leu-enkephalin was prepared by the solution method and its antinociceptive effect and inhibitory effect on the electrically induced contractions of mouse vas deferens were examined. The hybrid was synthesized by the coupling of Boc-Tyr-D-Ala-Gly-Phe-Leu-OH and amino-poly(ethylene glycol), followed by trifluoroacetic acid treatment. The hybrid showed more potent antinociceptive activity in mice and 120 times higher inhibitory activity in mouse vas deferens preparation than intact [D-Ala2]Leu-enkephalin.

Amino Acid Sequence↗
PubMed1994

Amino acids and peptides. XXIII. Leu-enkephalin analogs containing a fluorinated amino acid at position 2, 4 or 5.

Fluorinated analogs of Leu-enkephalin were synthesized by the solution method and the solid-phase method. The synthetic peptides were examined for opioid activities on mouse vas deferens and guinea pig ileum. Among the synthetic peptides,[D-Ala2,Leu(F3)(2R,4S)5]enkephalin and [D-Ala2,Leu(F3)(2S,4R)5]enkephalin exhibited potent opioid activity, and [Leu(F3)(2S,4R)5]enkephalin exhibited high delta-receptor selectivity.

Amino Acid Sequence↗
PubMed1994

Amino acids and peptides. XXIV. Preparation and antinociceptive effect of [D-Ala2,(N-Me)Phe4]enkephalin analog-poly(ethylene glycol) hybrids.

Hybrids of amino-poly(ethylene glycol) (aPEG) and [D-Ala2,(N-Me)Phe4] enkephalin analogs, H-Tyr-D-Ala-Gly-(Me)Phe-aPEG, H-Tyr-D-Ala-Gly-(Me)Phe-Leu-aPEG and H-Tyr-D-Ala-Gly-(Me)Phe-D-Leu-aPEG, were prepared by the solution method and their antinociceptive properties were examined in comparison with those of the peptides. H-Tyr-D-Ala-Gly-(Me)Phe-OH and H-Tyr-D-Ala-Gly-(Me)Phe-Leu-OH themselves at intracerebroventricular (i.c.v.) doses of 10-30 nmol/animal produced an antinociceptive effect which was less potent than that of i.c.v. morphine, 3 micrograms/animal, and H-Tyr-D-Ala-Gly-(Me)Phe-D-Leu-OH did not have any marked effect. However, the antinociceptive effects of H-Tyr-D-Ala-Gly-(Me)Phe-Leu-OH and H-Tyr-D-Ala-Gly-(Me)Phe-D-Leu-OH were remarkably potentiated by hybrid formation with aPEG to levels higher than that of 3 micrograms/mouse of morphine, and the effect lasted at least 120 min. In contrast, the effect of H-Tyr-D-Ala-Gly-(Me)Phe-OH was rather diminished by hybrid formation. In view of the low toxicity and weak immunogenic properties of aPEG, the hybrids could be useful in therapy of patients for relieving chronic and severe pain.

Amino Acid Sequence↗
PubMed1994

Amino acids and peptides. XX. Preparation of beta-cyclododecyl aspartate and its application to synthesis of fibronectin- and laminin-related peptides.

beta-Cyclododecyl aspartate was prepared and its application to peptide synthesis was examined. Derivatives of beta-cyclododecyl aspartate are more likely to crystallize and should be useful for peptide synthesis. The cyclododecyl ester was much stable to bases than the benzyl ester and rather more stable than the cyclohexyl ester. It was removable by HF treatment and trifluoromethanesulfonic acid treatment. beta-Cyclododecyl aspartate was used for synthesis of laminin- and fibronectin-related peptides by solid phase and liquid phase methods.

Amino Acid Sequence↗
PubMed1994

[Enzyme immunoassay of potassium oxonate using specific antibody isolated by immunosorbent gel].

An enzyme immunoassay for the determination of potassium oxonate in the plasma has been developed. The procedure is based on a competitive enzyme-linked immunosorbent assay using the second antibody solid phase method. The antiserum for potassium oxonate was prepared using oxonic acid 6-carboxypentylamide-BSA conjugate as immunogen. The specific antibody for oxonic acid was isolated from the antiserum using oxonic acid 6-carboxypentylamide immobilized immunosorbent gel. The purified antibody resulted in high sensitivity and low cross-reactivity as compared with the unpurified antiserum. Potassium oxonate in the plasma could be assayed in the range from 20 to 1000 ng/ml by the proposed EIA. The recovery was ranged from 82 to 117% and the coefficient of variation was from 6.6 to 14.7% (n = 6).

Antibody Specificity↗
PubMed1994

Vascularity of meningiomas and neuromas: assessment with dynamic susceptibility-contrast MR imaging.

OBJECTIVE: Dynamic susceptibility-contrast MR imaging provides hemodynamic information about normal and pathologic tissue of the brain. The purpose of this study was to determine the value of this technique in assessing the vascularity of meningiomas and neuromas. MATERIALS AND METHODS: Sixteen patients with extraaxial brain tumors (eight meningiomas and eight neuromas) and seven subjects without evident brain lesions were studied with a conventional 1.5-T MR unit. Dynamic susceptibility-contrast MR imaging was done with a gradient-echo technique (33/23/10 degrees [TR/TE/flip angle]) during bolus IV injection of 0.15 mmol/kg gadopentetate dimeglumine. The integral of the rate of change in T2* (integral of delta R2*dt) was calculated and compared among the brain tumors and normal brain. RESULTS: The mean integral of delta R2*dt value obtained was significantly higher in meningiomas than in neuromas (p < .001), which shows that meningiomas are generally more vascular than neuromas. We found no significant difference in the mean integral of delta R2*dt between neuromas and normal brain regions. CONCLUSION: Dynamic susceptibility-contrast MR imaging provides information about the degree of the vascularity of meningiomas and neuromas that is not available with conventional MR imaging.

Adult↗
PubMed1994

[Basic and clinical studies on serum cytokeratin 19 fragment assay using Centocor CYFRA 21-1 kit in patients with lung cancer].

We evaluated the newly developed tumor marker assay kit, "Centocor CYFRA 21-1", an immunoradiometric assay (IRMA) kit for determining the serum cytokeratin 19 fragment using the sera of healthy subjects, patients with benign lung diseases and patients with lung cancer. The assay procedure is simple and based on the one-step IRMA system. There were no problems in reproducibility, dilution test and recovery test. The minimum detectable dose was 0.3 ng/ml. The antigen measured by this kit was immunologically cross-reactive with tissue polypeptide antigen (TPA) and CYFRA 21-1 concentration was closely correlated with TPA concentration in the patient's serum (r = 0.86, p < 0.01). The cut-off value of serum CYFRA 21-1 based on the assay results of this kit was calculated to be 1.6 ng/ml from the receiver operating characteristic curve. Three of 47 healthy subjects (6.4%) and 9 of 30 patients with benign lung diseases (30.0%) showed a concentration over the cut-off value. By contrast, serum CYFRA 21-1 concentration was elevated in 31 of 50 patients with lung cancer (62.0%), 11 of 13 squamous cell carcinoma patients (84.6%), 8 of 12 small cell carcinoma patients (66.7%), 4 of 7 large cell carcinoma patients (57.1%) and 8 of 18 adenocarcinoma patients (44.4%). In addition, the positive rate of serum CYFRA 21-1 in patients with lung cancer gradually increased with staging of the disease: 50.0% in stage I, 50.0% in stage II, 61.9% in stage III, and 76.9% in stage IV. Thus, our results suggested that the Centocor CYFRA 21-1 kit is a useful assay system for serum cytokeratin 19 fragment as a tumor marker in patients with lung cancer.

Adult↗
PubMed1994

[Surgical repairs of anomalous pulmonary venous connection to superior vena cava and right atrial junction].

We recently encountered a case of total anomalous pulmonary venous connection (TAPVC, Darling Ib) and 3 cases of partial anomalous pulmonary venous connections (PAPVC) to the superior vena cava. We surgically treated these 4 cases by different procedures which were selected according to the morphological features of individual cases. In the case of TAPVC (Darling Ib), we created a right atrial wall flap, according to the method of Vargas, so that the blood from the abnormal pulmonary vein could pass the left atrium via the superior vena cava and atrial septal defect. In 3 cases of PAPVC, we modified some techniques of right atrial incision and closure by suturing. Through these surgical procedures, none of the 4 patients developed postoperative stenosis of the pulmonary venous pathway or arrhythmias. Various surgical procedures have been reported for the treatment of anomalous pulmonary venous connection, an anomaly involving direct connection of the pulmonary vein to the superior vena cava or to the right atrial junction of the superior vena cava. However, the incidence of postoperative stenosis or obstruction of the pulmonary venous pathway or postoperative sick sinus syndrome has been high with these procedures.

Adult↗
PubMed1994

[Use of Bullard intubating laryngoscope in emergency room].

A sixty-year-old male patient with caries of the cervical spine suffered from cardio-respiratory arrest outside the hospital. Laryngeal mask was inserted into his pharynx and he was brought to the emergency department of our hospital under CPR by emergency paramedical staffs. Endotracheal intubation was tried three times with a Macintosh laryngoscope but was unsuccessful. His neck was difficult to extend and his epiglottis was not visible at all (X-ray photograph showed the fusion and the significant backward protrusion of his cervical spine). EGTA and Combitube were tried but in vain. At last Bullard intubating laryngoscope with videocamera system was operated. An endotracheal tube was easily inserted into his trachea with it and effective cardiopulmonary resuscitation was managed under reliable airway maintenance. These facts indicate that Bullard intubating laryngoscope is valuable at the emergency department and it should be always available there.

Cardiopulmonary Resuscitation↗
PubMed1994

[Nonsurgical retrieval of intravascular catheter fragments].

The incidence of catheter fragment induced by iatrogenic accident has been increasing because of frequent use of intravenous catheters and catheterization in daily practice. Migrated intravascular fragments from broken catheters were retrieved transcutaneously in four cases. All fragments were removed safely using biotome, multipurpose grasping forceps and basket catheter. But in a case which the fragment was lodged in the pulmonary artery, retrieval was not easy and it took many times. Fragments lodged in the right ventricle and in the pulmonary artery cause many complications including deaths. So broken fragments should be removed as soon as possible, before it migrated to there.

Adolescent↗
PubMed1994

[A case report of successful management of intraoperative aortic dissection during aorta-coronary bypass and aortic valve replacement].

A 70-year-old woman underwent aortic valve replacement and coronary artery bypass surgery with a saphenous vein graft for aortic regurgitation and 99% stenosis in the right coronary artery. During the period of weaning from the cardiopulmonary bypass enlargement of the ascending aorta and bleeding from the suture line were observed. The intraoperative diagnosis of ascending aortic dissection (DeBakey type I) was made with transesophageal and transthoracic echocardiography. Cardiopulmonary bypass was reinstituted and the patients was cooled to 20 degrees C. Under circulatory arrest and continuous retrograde cerebral perfusion through the superior vena cava the intimal tear at the point of infusion cannula was removed and the ascending aorta was reconstructed by direct suture bolstered with Teflon felt strips. Following completion of the repair no further dissection was seen, and the patient was successfully weaned from cardiopulmonary bypass. There were no signs of neurologic complications. Although intraoperative aortic dissection is uncommon, it can be a fatal iatrogenic complication of cardiac operations. Prompt recognition and surgical repair of the injuries are essential to achieve a successful outcome. The combination of transesophageal echocardiography and transthoracic echocardiography permits the immediate diagnosis of aortic dissection. And it is suggested that continuous retrograde cerebral perfusion through the superior vena cava protects the brain for 52 minutes of cerebral circulatory arrest at the lowest nasopharyngeal temperature of 18.7 degrees C. This technique is simple, and required neither special preoperative preparation or special equipment, so that it is suitable especially for intraoperative aortic dissection such as this case.

Aged↗
PubMed1994

[A successful case of external conduit operation for tetralogy of Fallot with pulmonary atresia at the age of 17 months].

We report a successful case of external conduit operation in a 7.2 kg male infant. A 17-month-old boy was admitted because of increasing cyanosis and polycythemia. He had undergone classical Blalock-Taussig shunt at the age of 51 days with the diagnosis of tetralogy of Fallot with pulmonary atresia. Cardiac catheterization showed stenosis of the right pulmonary artery related to the site of the shunt. We chose external conduit operation and correction of the right pulmonary artery stenosis instead of additional shunt and correction of the stenosis with cardiopulmonary bypass. He is in a good postoperative condition. It is preferable that external conduit operation is applied to similar infant cases from the standpoint of exercise ability, myocardial degeneration and postoperative arrhythmia.

Blood Vessel Prosthesis↗
PubMed1994

[The indications and limitations of open heart surgery without homologous blood transfusion in children and infants].

Open heart surgery without homologous blood transfusion in adults is a generalized method, but not in children and infants. We have attempted to perform open heart surgery without blood transfusion in small children and infants, and report here our experiences and ideas in this regard. The number of open heart surgeries we performed on patients less than 15 years old was 117 from April 1988 to April 1993. In 57 patients among them we attempted open heart surgery with bloodless priming in the cardiopulmonary bypass circuit. Eleven patients were given blood transfusion during the operation or the post-operative period. Another 46 discharged without blood transfusion. From April 1988 to December 1990 (the earlier period) we used the conventional style cardio-pulmonary bypass circuit with gravity venous drainage for 12 patients undergoing open heart surgery without blood transfusion. The lowest weight of these patients was 13 kg and the main diseases were ASD and mild VSD. From January 1991 to April 1993 (the later period), we used the new type cardio-pulmonary bypass circuit with lower priming volume for 34 patients undergoing open heart surgery without blood transfusion. The youngest age was 7 months and the lowest weight was 6.5 kg. The diseases were ASD (9), mild VSD and VSD/PH (15), TOF (6) and other (4). In the new cardiopulmonary bypass system, the venous reservoir and cardiotomy sucker are given negative pressure ((-10)-(-40) mmHg) with a vacuum not a pump, and only one roller pump is used for the arterial pump.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗