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Biomedical subjects

A Maeda

Publications and source records attributed to A Maeda.

At least 307 records · Page 17Linked to original sources
PubMed1991

Surface blood flow and histology of human anterior cruciate ligament allografts.

We measured surface blood flow in 53 anterior cruciate ligaments (ACLs) reconstructed with allogeneic tendon grafts using laser Doppler flowmetry and examined their histology through biopsy specimens procured during second-look arthroscopy to investigate the fate of ACL allografts on a long-term basis. The age of the grafts, i.e., time from the reconstruction to the second-look arthroscopy, ranged from 6 to 89 months. Six-month grafts showed significantly higher blood flow than the other older ones from 12 to 89 months, which showed a blood flow level equivalent to normal control ACLs. Histological studies revealed that ACL allografts remodeled with time, and that they reached stability by 18 months postimplantation. These results confirmed the concepts of age-dependent remodeling of allografts and their longevity in the human knee joint.

Adult↗
PubMed1991

Inactivation of kanamycin A by phosphorylation in pathogenic Nocardia.

Among the five species of pathogenic Nocardia, i.e., N. asteroides, N. brasiliensis, N. farcinica, N. nova and N. otitidiscaviarum, all strains of N. brasiliensis and N. farcinica showed resistance to an aminoglycoside antibiotic, kanamycin A, showing the MIC (minimum inhibitory concentration) values of more than 100 micrograms/ml. This species-specific difference in sensitivity was found to be explained by the production of an inactivation enzyme, aminoglycoside 3'-phosphotransferase APH(3'). Structural studies by mass and NMR spectroscopy on the inactivated substance produced by a cell-free extract of the Nocardia confirmed the conversion of kanamycin A to an inactive substance, kanamycin A 3'-phosphate. The MIC values of N. otitidiscaviarum and N. nova for kanamycin A, on the other hand, ranged from 0.78 micrograms/ml to 100 micrograms/ml, and both species were non-producers of APH(3'). Sensitivity to the antibiotic and APH(3') productivity of N. asteroides varied depending on the strain.

Carbohydrate Sequence↗
PubMed1991

[Polycythemia vera with der(15) and der(20) associated with remarkable neutrophilia].

An autopsy case of polycythemia vera with der(15) and der(20) associated with remarkable neutrophilia was reported. A 87-year-old man was diagnosed as polycythemia vera in August 1987. The red blood cell count was 621 x 10(4)/microliters, Ht 58.5% and the white blood cell count 45,400/microliters with 92% neutrophils. The splenomegaly, increased red blood cell volume and the low erythropoietin level were present. The arterial SaO2 value was above 92%. The chromosome analysis of bone marrow cells revealed 46, XY, -15, -20, +der(15)t(15;?)(q13-15;?), +der(20)t(20;?)(q11;?). The breakpoint in No. 20 was in q11. The remarkable leukocytosis with relative and absolute neutrophilia were observed. Particularly late in the clinical course the white blood cell count was 92,900/microliters with 99% neutrophils. The Ph1 chromosome was negative and the bcr rearrangement was not detected. He died of bronchopneumonia in January 1989. At the autopsy findings neither the marrow fibrosis nor the extramedullary leukemic cell infiltration was noticed.

Aged↗
PubMed1991

[A case of effective preoperative chemotherapy in alveolar soft part sarcoma].

Alveolar soft part sarcoma is primarily treated by surgery, and reports of effective chemotherapy have been infrequent. We experienced a patient with alveolar soft part sarcoma in the left thigh, in whom preoperative chemotherapy with cisplatinum (CDDP) and adriamycin (ADM) was effective. This patient was a 13-year-old male who had an elastic hard mass with the size of his fist in the medial thigh. Plain X-ray revealed bone destruction with periosteal reactions in the distal diaphysis of the femur. Biopsy specimen showed alveolar growth of relatively large cells with eosinophilic or clear cytoplasm. PAS staining was positive in microgranular patterns in part of the cells, but no crystalline structure were observed. A diagnosis of alveolar soft part sarcoma was made, and chemotherapy was started. After administration of 150 mg of CDDP intraarterially twice and 50 mg of ADM intravenously 5 times, effectiveness of chemotherapy was estimated by physical and radiological findings. In the resected specimen, the margins of the soft part tumor showed shell-like ossification, suggesting the subperiosteal or intraosteal origin. Histology of the removed specimen showed that the tumor was mostly replaced by fibrous tissues, indicating the effectiveness of the preoperative chemotherapy. This disease has a relatively long course, however, the present case is considered to be another exceptional case that responded to preoperative chemotherapy.

Adolescent↗
PubMed1991

[Clinical efficacy of cefpirome against various infectious diseases in children].

The clinical efficacy and the pharmacokinetics of cefpirome (CPR, HR 810), a new semisynthetic cephalosporin derivative, were investigated in children with various infectious diseases. CPR showed high blood peak levels, relatively long half-life and high levels in urine. Excellent clinical efficacy was obtained in 2/3 cases with pneumonia, 3/4 cases with upper respiratory infection, 2/2 cases with cutaneous and soft tissue infection and 1/1 case with urinary tract infection. The overall efficacy rate was 80%. No clinical adverse effects were observed while slightly elevated GPT and GOT, decreased platelet were detected in 4 cases without clinical problems. CPR should be an useful and safe drug in treating infectious diseases in children.

Adolescent↗
PubMed1990

Toxicokinetic study of norfloxacin-induced arthropathy in juvenile animals.

A toxicokinetic study of norfloxacin-induced arthropathy in juvenile animals was undertaken using nalidixic acid as a standard drug. Norfloxacin and nalidixic acid were subcutaneously administered to rats and rabbits, orally administered to dogs, and norfloxacin was orally dosed to monkeys once a day for 7 consecutive days. Of the dose levels tested, the minimum arthropathic doses of norfloxacin were 100, 25, and 50 mg/kg/day in rats, rabbits, and dogs, respectively. At these doses, the peak serum concentrations (Cmax) on Day 6 were 16.1, 9.73, and 5.11 micrograms/ml, and the areas under the serum concentration/time curve (AUC0----infinity) were 31.9, 22.9, and 26.2 micrograms.hr/ml, in respective animals. Monkeys showed no arthropathy with norfloxacin at doses of less than 500 mg/kg/day, at which the Cmax and AUC0----infinity were 15.6 micrograms/ml and 103 micrograms.hr/ml, respectively. The minimum arthropathic doses of nalidixic acid were 50, 100, and 25 mg/kg/day in rats, rabbits, and dogs, respectively. The Cmax and AUC0----infinity of nalidixic acid were higher than those of norfloxacin in all animals. Joint tissues took up more norfloxacin than nalidixic acid, but when arthropathy was present the articular cartilage concentrations of the two drugs were in the same range. The penetration of norfloxacin into the articular cartilage was the same regardless of the joint's anatomical locations, but differed among species, being highest in rats and lowest in monkeys. The Cmax and AUC0----infinity of norfloxacin in animals at their arthropathic doses were far higher than those measured clinically in children, whereas those of nalidixic acid in animals did not differ much from its clinical parameters.

Administration, Oral↗
PubMed1990

Massive pulmonary tumor emboli in osteosarcoma. Occult and fatal complication.

The lung is the most frequent site of metastasis in osteosarcoma, but extensive intraluminal tumor growth in pulmonary arteries is rare. Two patients with osteosarcoma in whom the tumors grew in the pulmonary artery and caused massive pulmonary emboli are reported. Histologically the tumor emboli were myxoid and different from the primary lesion and the other metastases, which were osteoblastic in one case and chondroblastic in another case. In both cases the pulmonary tumor emboli were the cause of death.

Adolescent↗
PubMed1990

A toxic substance produced by Nocardia otitidiscaviarum isolated from cutaneous nocardiosis.

During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans.

Aged↗
PubMed1990

Intra-operative pulmonary embolism after intravesical instillation of formalin.

Intra-operative pulmonary embolism is a rare and severe complication which is difficult to diagnose. A case is reported in which this condition occurred after intravesical instillation of formalin during radical cystectomy under general anaesthesia. Formalin may be related to formation of intravascular thrombi and result in pulmonary embolism.

Anesthesia, General↗