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Biomedical subjects

M Kuwabara

Publications and source records attributed to M Kuwabara.

At least 127 records · Page 7Linked to original sources
PubMed1994

Induction of lung tumors in C3H strain mice after single or fractionated irradiation with X-rays.

Murine model for lung tumor induction was studied in C3H/He male mice, a strain with low spontaneous incidence of lung tumors. Dose-response relationships in lung tumor induction were compared following irradiation with single doses and split doses of X-rays to the thorax either at night or in the daytime. The tumor incidence after a single 1.25 Gy dose at night during the period of nocturnal activity almost reached the maximum level after a 5 Gy dose in the daytime. Proliferative activity determined by observing the labeling index with tritiated thymidine in the normal lung was low as a whole, but tended to decrease in the daytime. When the proliferative response was induced by X-irradiation, significantly higher activity was observed at night. These circadian fluctuations were thought to affect radiosensitivity and lung tumor induction in mice. When split doses or fractionated doses of X-rays were applied to the thorax, lung tumor incidence definitely increased. The incidence after two 7.5 Gy doses with a 12 hr-interval was 41%, 3-fold higher than that after a single 15 Gy dose. Moreover, fractionated whole body irradiations (three times at 3 Gy with 3-month-interval) after a single 7.5 Gy thoracic irradiation was most effective in increasing not only the incidence (47%) but also the multiplicity of the lung tumor. More than 30% of tumor-bearing mice had two or more tumors following thoracic and whole body irradiations, while only 10% of tumor-bearers had multiple tumors after single or fractionated thoracic irradiation alone.

Animals↗
PubMed1994

Magnetic resonance imaging of young and aged rat brains under a magnetic field of 7.05 T.

Using a homemade MR imaging probe (Helmoholtz coil), MR images of brains of 5-week-old and 23- or 24-month-old Wistar rats were taken under a magnetic field of 7.05 T (Tesla). The probe was designed to fit the rat head and made by winding thin copper film round an acrylic tube with a 5-cm i.d., 10-cm length and 2-mm thickness. This was adjusted to resonate with the 300 MHz radiofrequency corresponding to the resonance frequency of 1H under a magnetic field of 7.05 T. MR images were obtained by T1-weighted and two-dimensional Fourier transformation techniques. The sagittal and coronal sections were imaged in 1-mm-thick slices. The size of the data matrix was 128 phase-encoded steps. Each image was obtained through eight acquisitions. A comparison of the MR images with those semi-microscopically taken at the same position of the coronal section revealed that the cerebral cortex, hippocampus, hypothalamus and thalamus were clearly imaged by this probe. With aging, MR images of cerebral cortices were observed with decreased signal intensities. Enlargement of the third ventricles and hypertrophy of cranical parietal bones were also recognized in sagittal MR images of aged rats. These observations were more marked in males than in females. From these observations it was concluded that this probe was applicable for MR imaging of rat brains under a magnetic field of 7.05 T.

Aging↗
PubMed1994

Characterization of new inbred strains of Dahl-Iwai salt-sensitive and salt-resistant rats.

Dahl-Iwai salt-sensitive (S) and salt-resistant (R) rat strains were newly established as inbred strains. To characterize the strains, the Dahl-Iwai S and R rats were fed low-salt (0.3% NaCl) and high-salt (8.0% NaCl) diets from 5 weeks after birth, and systolic blood pressure and pathologic findings were examined at intervals. The distributions of alleles at 19 biochemical and immunologic loci also were examined in the aforementioned strains, together with those for the inbred SS/Sea and SR/Sea strains, which were derived from inbred SS/Jr and SR/Jr strains, respectively. The Dahl-Iwai S rats were hypertensive after 3 weeks of consuming the 8.0% NaCl diet and died from 6 to 10 weeks after the diet was initiated. Renal lesions developed after 4 weeks' consumption of the high-salt diet. The Dahl-Iwai S rats were not hypertensive until at least the age of 21 weeks while they consumed the 0.3% NaCl diet, whereas it was reported that the SS/Jr rats became hypertensive at about 20 weeks of age when they consumed the low-salt diet. The Dahl-Iwai R rats were normotensive whether fed the 0.3 or 8.0% NaCl diet. Hydronephrosis was not observed in the Dahl-Iwai R rats, though it develops in SR/Jr rats with high frequency. Different distributions were detected for kidney alkaline phosphatase-1 (Akp-1) and amylase-1 (Amy-1) alleles between the Dahl-Iwai S and SS/Sea strains, and for esterase-14 (Es-14) and seminal vesicle protein-1 (Svp-1) alleles between the Dahl-Iwai R and SR/Sea strains. The phenotypic differences between the substrains of inbred Dahl rats could be ascribed to different genetic backgrounds.

Aging↗
PubMed1994

[Amebic empyema, a case report].

A 49-year-old man was admitted to our hospital for dyspnea. Chest X-ray examination showed a massive right pleural effusion. Using intrathoracic tube drainage, a large quantity of chocolate-like pleural effusion was removed. Laboratory data demonstrated severe anemia and hypoproteinemia, and TPHA was positive. Antiameba antibody in blood was high, and a liver abscess was demonstrated on abdominal CT scan. Amebic liver abscess and amebic empyema were thus diagnosed. With pleural tube drainage and percutaneous liver abscess drainage, metronidazole (1.5 g/day) was administered. After administering this drug, the high temperature normalized and the patient's general condition improved significantly. Recently, amebic infections have been reported in increased numbers, especially in male homosexuals and immunocompromised patients. Henceforth amebic infection should be considered when pleural effusion and empyema are suspected.

Empyema, Pleural↗
PubMed1994

[Clinical efficacy of arbekacin in deep MRSA infection. Including follow-up study after the termination of chemotherapy].

We analyzed the efficacy of arbekacin (ABK) using monotherapy or combined therapy on deep MRSA infection to find the most adequate usage of the drug. We also followed-up the isolation incidence of MRSA after the end of chemotherapy. The results are summarized as follows: 1. Clinical efficacy of ABK on 29 pneumonia and 3 septicemia due to MRSA was 42.9% in ABK monotherapy (9 patients), 62.5% in combined therapy with ABK and minocycline (9 patients), 100% with ABK and imipenem/cilastatin (IPM/CS) (7 patients), and 100% with ABK and other drugs (7 patients). 2. As for microbiological efficacy, combined therapy with ABK and IPM/CS or other drug was superior to other methods. Among patients from whom two or more species of bacteria were isolated, causative bacteria persisted in many cases, and some replacements occurred. 3. Kidney functions deteriorated in two patients that underwent monotherapy or combined therapy with ABK and IPM/CS, but they recovered when therapy was completed the completion. 4. In the three month follow-up study after ABK therapy, we found four cases of renewed infections after disappearance of MRSA. When just decreases in the number of MRSA resulted upon the chemotherapy, the relapse occurred in all cases. 5. Above results indicate that ABK is effective in MRSA infection, and combined therapy with beta-lactams is superior to other methods in serious MRSA infections. We also suggest that chemotherapy should be continued until the complete disappearance of MRSA is achieved.

Adult↗
PubMed1994

[Experience with atrioventricular valve replacement in infants and children].

From 1980 to 1989, nine infants and children underwent valve replacement. These replacements consisted of seven mitral valve replacement (MVR), one left atrioventricular valve replacement, and one aortic valve (AVR) replacement. We excluded AVR from this report. Follow-up period of 8 cases were 68 months in an average. During this period, 2 cases were not thought to be satisfactory as antithrombotic therapy, in which one revealed malfunctioning prosthesis, and secondary MVR implantation was performed. Another one is free from any complications. We experienced the difficulty of antithrombotic therapy following valve replacement in infants and children. It is supposed that combined use of anticoagulant therapy agent and antiplatelet agent may be necessary as antithrombotic therapy, especially in childhood.

Adolescent↗
PubMed1993

Development and application of an enzyme immunoassay for tenascin.

A sandwich enzyme immunoassay system for detecting tenascin in human serum was established using purified antibodies to tenascin. The assay system comprises polystyrene balls with immobilized polyclonal antibody F(ab')2 fragments and monoclonal antibody F(ab')2 fragments labeled with beta-D-galactosidase from Escherichia coli. The assay system has a minimum detectable sensitivity of 10 ng/ml of tenascin in human serum, with an assay range of 3 micrograms/ml. The assay system was found not to cross-react with laminin, vitronectin, human epidermal growth factor, fibrinogen, or fibronectin. Coefficients of variation within-run and between-run for the assay of human serum tenascin were less than 10%. Serum samples from healthy adults (n = 86) contained about 800 ng/ml and serum tenascin concentrations of patients with carcinoma (n = 47) were increased. These results suggest that tenascin in serum might be a marker substance for carcinoma.

Adult↗
PubMed1993

Spin-trapping detection of precursors of hydroxyl-radical-induced DNA damage: identification of precursor radicals of DNA strand breaks in oligo(dC)10 and oligo(dT)10.

A spin-trapping method combined with enzymatic digestion and high-performance liquid chromatography was employed to detect hydroxyl-radical-induced precursors of strand breaks in oligonucleotides ((dC)10 and (dT)10) as DNA models. Radicals produced as precursors of both strand breaks and base alterations were first trapped by the spin trap 2-methyl-2-nitrosopropane. The oligonucleotides containing spin adducts were subsequently digested by snake venom phosphodiesterase to release low-molecular-weight nitroxide fragments. In this way, several spin adducts were separated by high-performance liquid chromatography. In both oligonucleotides, ESR spectra attributable to the spin adducts derived from trapping of a precursor radical of strand breaks (the C4'-sugar radical) were observed. To further confirm this assignment, the induction of strand breaks was examined by polyacrylamide gel electrophoresis of 5'-32P-end-labeled oligonucleotides. Autoradiograms of the gels showed that the fragments corresponding to monomers to 9mers were formed in both oligonucleotides. When experiments were carried out under conditions in which hydroxyl radicals reacted with oligomers in the presence of the spin trap, the spin trap was found to suppress the fragmentation more than it did by scavenging hydroxyl radicals, indicating that the precursor radical of strand breaks (the C4' radical) was trapped. The present experiments showed that the spin-trapping method combined with gel electrophoresis was a good approach to identify sites of radical damage which cause strand breaks in oligonucleotides (probably in DNA).

DNA Damage↗
PubMed1993

Hemangioma of the upper arm associated with massive hemorrhage in a neonate.

A rare case of an ulcerated hemangioma of the upper arm in a neonate is described herein. Resection of the huge hemangioma, which occupied the axilla and extended down the entire length of the upper arm, was necessary due to massive hemorrhage from the ulcer and progressive heart failure caused by the arteriovenous fistula in the hemangioma. After complete resection of the hemangioma, extensive defects of the skin and subcutaneous tissue were replaced by a skin flap closure technique which involved considerable difficulty. However, the arm gradually recovered its size and function with good wound healing. The present case illustrates that rapid surgical intervention may be required to prevent clinical deterioration in such cases.

Arm↗
PubMed1993

An infant with bilateral adrenal neuroblastoma found by mass-screening: report of a case.

A male infant with bilateral adrenal neuroblastoma found by mass-screening is herein reported. The patient presented with almost equal-sized tumors, each remaining confined to the respective adrenal gland without crossing the midline. No other tumorous lesion was evident. The two adrenal tumors had similar histologic features and appeared to have grown concurrently. Such simultaneous occurrence of primary adrenal neuroblastoma is unusual, and appears to reflect the multicentric origin of this tumor.

Adrenal Gland Neoplasms↗
PubMed1993

Contact microradiographic analysis of feline tooth resorptive lesions.

Feline tooth resorptive lesions were studied using contact microradiographic analysis of ground sections. Contact microdiagram films were developed with a PIAS-imaging device, and decalcification patterns were evaluated, revealing a clear boundary between normal tissue and the resorptive area, which was different from the image of dental caries in humans. By contrasting analysis, decalcification signs appearing in human caries were not observed in feline resorptive lesions.

Adult↗
PubMed1993

Immunothermotherapy and related TNS induction in mice.

Induction of tumor necrosis factor in sera (TNS) as a multidisciplinary cancer therapy by the administration of a combination of 2-carboxyethylgermanium sesquioxide (Ge-132) and lipopolysaccharide (LPS) on Meth-A sarcoma-bearing mice was attempted. In addition to the above TNS induction therapy (TNS therapy) per se, the potential on the above parameters by employing a multidisciplinary cancer therapy (immunothermotherapy), in which TNS therapy was coupled with regional hyperthermia treatment, was investigated. This immunothermotherapy enhanced the antitumor effects produced by the above TNS therapy.

Animals↗
PubMed1993

Effects of 2-carboxythylgerumanium sesquioxide (Ge-132) as an immunological modifier of post-surgical immunosuppression in dogs.

The effect of 2-carboxythylgerumanium sesquioxide (Ge-132) as an interferon-gamma (IFN-gamma) inducer on post-surgical immunosuppression was evaluated from the immunological response augmented in canine neutrophils, macrophages and peripheral blood lymphocytes (PBL) using the chemiluminescence technique. Experimental gastrotomy was performed on dogs in two groups; one group was subjected to sham-surgery without any medication, and the other was treated by Ge-132 administration at 24 hr before operation. Although the phagocytic activities of neutrophils, macrophages and PBL in the sham-operated group were depressed transiently after surgery, those in the Ge-132-administered group (Ge-132 group) were enhanced for a long time after surgery. It appeared that the generated free radical, which blocked the phagocytosis of macrophages and PBL, was activated by IFN-gamma. These results suggest that Ge-132 pre-treatment may be efficacious and useful in preventing the multifaceted clinical symptoms induced by post-operative immunosuppression in dogs.

Animals↗
PubMed1993

Spin-trapping and chemiluminescence studies of neutrophils from a Holstein-Friesian calf with bovine leukocyte adhesion deficiency.

The ability of neutrophils from a Holstein-Friesian calf with bovine leukocyte adhesion deficiency (the proband with a genetic deficiency of the Mac-1 (CD11b/CD18) glycoprotein corresponding to the receptor of complement iC3b) to generate oxygen radicals was examined using electron spin resonance spectrometry (ESR) combined with a spin-trapping technique and luminol-dependent chemiluminescence spectrometry. When the neutrophils were stimulated with phorbol 12-myristate 13-acetate (PMA), an ESR spectrum confirming the generation of superoxide anions (O2-) was clearly observed in both healthy and diseased calves. However, when the neutrophils were stimulated by opsonized zymosan, appearance of the ESR spectrum was recognized in the healthy calves but not in the diseased calf. Similar results were obtained from chemiluminescence experiments.

Animals↗
PubMed1993

[A case of pulmonary lymphangiomyomatosis treated with bilateral oophorectomy and methyl-progesterone-acetate].

A case of pulmonary lymphangiomyomatosis is reported. A 37-year-old woman was admitted with hemosputum and dyspnea on exertion. Chest roentgenogram revealed diffuse reticulonodular shadows and arterial hypoxemia was present. Pulmonary function tests showed severe restrictive & obstructive impairment, and pulmonary perfusion scintigraphy with 99mTc-MAA showed non-segmental disproportion. The histological diagnosis of pulmonary lymphangiomyomatosis was made by transbronchial lung biopsy. She underwent bilateral oophorectomy under general anesthesia. However, the arterial hypoxemia advanced gradually, and medroxyprogesterone-acetate (MPA) was commenced (200 mg/day). Her condition remained stable after the description of MPA.

Adult↗