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Biomedical subjects

M Usui

Publications and source records attributed to M Usui.

At least 289 records · Page 16Linked to original sources
PubMed1987

[Significance of surgical adjuvant chemotherapy in osteosarcoma].

The primary site of the metastasis of osteosarcoma is the lung. More than 90% of patients have died of pulmonary metastasis in one to two years. Control of osteosarcoma depend upon the prevention of its pulmonary metastasis. The introduction of chemotherapy consisting mainly of Adriamycin, high-dose methotrexate with Leucovorin rescue and Cisplatinum, dramatically improved the prognosis of osteosarcoma. In the past, when systemic chemotherapy was not available, the five-year survival rate was around 19%. In patients who receive chemotherapy with the current combination of chemotherapeutic agents (ADM, HD-MTX, VCR, CPM, CDDP), the incidence of pulmonary metastasis was low, and the five-year survival rate increased to 65%. In patients who receive chemotherapy, pulmonary metastasis may be either delayed, with a single metastasis appearing after termination of treatment (late isolated type), or early and multiple, emerging in reaction to treatment (early multiple type). It is generally accepted that post-operative chemotherapy can inhibit pulmonary micro metastasis and prove to be of great significance in improving the survival rate of patients with osteosarcoma of extremities and achieve limb salvage operation. On the other hand, effective control of the side effects of drug administration such as nausea, vomiting, alopecia, cardio (ADM) and renal (CDDP) toxicity and bone marrow suppression, is a problem that must be solved as soon as possible.

Adolescent↗
PubMed1987

[A case of transient cerebral ischemia of the vertebrobasilar system caused by carotid ulcerative lesion and persistent proatlantal intersegmental artery: a case report].

A rare case with the episodes of vertebrobasilar TIAs which were caused by carotid ulcerative lesion and by persistence of proatlantal intersegmental artery is reported. This 69-year-old man was admitted on 14th Feb. 1985 with complaints of three attacks of vertigo, diplopia, nausea, vomiting and dysequilibrium lasting about 1 hour. His past history and family history were unremarkable. On admission, physical and neurological examinations revealed nothing particular, except bilateral carotid bruits. On the right side, innocent low pitched bruit was detected, however on the left side, carotid bruit was high pitched and was regarded as pathological. Blood pressure was 180/80 mmHg. Pulse rate was 66/min and cardiac arrhythmia was not detected by EKG. He also had no history of cardiac arrhythmia as mentioned above. CT scans and MRI showed only mild brain atrophy and no brain stem nor cerebellar lesions. Left carotid angiogram revealed ulcerative lesion of the common carotid bifurcation which was compatible with high pitched bruit. And at the level of the C2 vertebra, persistent proatlantal intersegmental artery originated from the left internal carotid artery which, after running upward, joined to the horizontal portion of the left vertebral artery above the atlas. Internal carotid and the vertebrobasilar vasculature beyond the proatlantal intersegmental artery were normal except slight irregularity of carotid siphon. Right carotid and vertebral angiograms revealed no abnormality and basilar artery was opacified clearly again via right vertebral artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Identification of HETE in the rat brain and its relevance to ischemic cerebral edema: Part 2].

We reported the detection of 11-hydroxy-eicosatetraenoic acid(HETE) in rat brain and its relevancy to ischemic brain edema. But the further study disclosed that the peak of 11-HETE on high performance liquid chromatography (HPLC) had been contaminated by dibutyl phthalate. The results and our speculation about the roles of 11-HETE in ischemic brain turned out to be incorrect. Re-examination of lipoxygenase products in rat brain was performed using gas chromatography-mass spectrometry (GC-MS) and HPLC. The rat middle cerebral artery (MCA) occlusion model was used. The rat was sacrificed by in situ freezing 24 and 72 hours after MCA occlusion. The identification and quantitative study of HETEs in normal and ischemic rat brain was performed by HPLC and GC-MS. In the present study, several kinds of HPLC were used to prevent misinterpretation by the contamination. Sham operated control rat brain contained only 15-HETE and its content was 2.1 +/- 2.1 (mean +/- SE) ng/g wet weight. In 24 hours ischemic brain, 11-HETE newly appeared and the 15-HETE content was increased. But these increases were not statistically significant. The hemisphere rendered ischemic for 72 hours contained all HETEs, namely, 5,9-, 8- and 12-, 11-, and 15-HETEs. Their amounts were 18.3 +/- 2.8, 16.6 +/- 3.0, 23.7 +/- 14.9, 14.0 +/- 3.4, 19.8 +/- 5.5 ng/g wet weight, respectively. All HETE contents except 8- and 12-HETEs were significantly increased 72 hours after MCA occlusion when ischemic cerebral edema reached its maximum (p less than 0.01, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Functional analysis of cloned macrophage hybridomas. V. Induction of suppressor T cell responses.

It has been suggested that macrophage-like accessory cells are involved in suppressor T cell (Ts) induction. To further analyze this issue, we obtained several cloned macrophage hybridoma cell lines by somatic cell fusion of the macrophage tumor P388D1 of DBA/2 (H-2d) origin with splenic adherent cells of CKB mice (H-2k). Several cloned lines displayed the serological and functional characteristics of macrophages. We evaluated the ability of these hybridomas to induce third order or effector Ts (Ts3) to suppress the contact sensitivity response against the hapten 4-hydroxy-3-nitrophenyl acetyl (NP). In contrast to the parental P388D1 and two other macrophage hybridomas, one macrophage hybridoma clone, termed 63, when conjugated with NP, induced Ts3, which suppressed contact sensitivity responses against NP but not DNFB, showing that the Ts3 were antigen specific. Macrophage hybridoma 63 could specifically induce Ts3 activity in either H-2k, H-2d, or H-2k/H-2d heterozygous hosts. Thus, macrophage hybridoma 63 functionally expressed major histocompatibility complex-related restricting determinants, and the fusion with cells from a H-2k macrophage donor caused a functional complementation of H-2d-related, Ts-inducing elements. The genetic restriction governing induction of Ts3 was controlled by genes that mapped to I-J region. Furthermore, NP-conjugated macrophage hybridoma 63 could serve as a target for elicitation of suppressor responses after administration of I-Jk, but not I-Jb, restricted suppressor factor. The data suggest that macrophage hybridomas represent a means to dissect heterogeneity within the macrophage population. The data also imply that the I-J determinants expressed on macrophages represent a ligand for the antigen receptor of Ts.

Animals↗
PubMed1986

Simultaneous reconstruction of bone and skin defects by free fibular graft with a skin flap.

It has been very difficult to accomplish simultaneous reconstruction of a massive defect of the long bone associated with a large skin defect. Yoshimura et al reported a new procedure using a vascularized free fibular transplant with a monitoring flap. This procedure was used in four cases that had resulted in massive bone and skin defects after wide resection of benign and malignant bone tumors occurring in the long bones. Our results using the composite vascularized fibular graft were gratifying.

Adolescent↗
PubMed1986

Long-term results of Kienböck's disease treated by excisional arthroplasty with a silicone implant or coiled palmaris longus tendon.

Of 32 patients with Kienböck's disease, 19 had lunate silicone implant replacements, and 13 had coiled palmaris longus tendon replacement. The carpal height was measured and osteoarthritic changes were noted in plain x-ray films before and after the operation. Follow-up periods ranged from 3 to 11 years, with an average of 6 years 4 months. In patients in the mild stages of the preoperative carpal collapse, both excisional arthroplasties had good clinical results. The x-ray films showed that a silicone implant played a more important role in preventing further carpal collapse than a palmaris longus tendon replacement in patients in the early carpal collapse stage. However, the clinical results of the silicone implant replacement were unsatisfactory because of the postoperative progression of osteoarthritic changes or subluxation of the prosthesis in the advanced stages of carpal collapse. The palmaris longus tendon replacement gave satisfactory results in four of seven patients with advanced carpal collapse. These results suggest that silicone implant replacement is indicated primarily in patients with the early stages of carpal collapse, and replacement of the palmaris longus tendon is rarely recommended in either the early or late stages of carpal collapse.

Adult↗
PubMed1986

Microsurgical reconstructive surgery following wide resection of bone and soft tissue sarcomas in the upper extremities.

A preliminary report is presented of six cases of microsurgical tissue transfer following wide tumor resection, utilizing free vascularized fibula graft (five cases) and free vascularized muscle graft (one case). In five cases, the grafted tissue survived completely, and the attempted functional reconstruction was successful. Although the follow-up period has been relatively short, there has been no local recurrence or distant metastasis in any of the cases.

Adolescent↗
PubMed1986

Biological, functional and morphological characteristics of human bone and soft tissue tumors in nude mice.

Since 1975, we have performed experiments on transplantation of bone and soft tissue tumors obtained, from 115 patients into nude mouse. In the present study, we analyzed biological, functional and morphological characteristics of the tumors transplanted in nude mice. The incidence of tumor take in the initial transplantation was 55.6% (40 of 72 cases) for malignant bone tumors, 42.9% (15 of 35 cases) for malignant soft tissue tumors and 0% for benign bone and soft tissue tumors. In particular, the incidence of tumor take was high for osteosarcoma (60%, 36 of 60 cases) and for rhabdomyosarcoma (70%, 7 of 10 cases). There were 22 tumors transplanted serially for more than 5 passages. The mean survival time for mice with serially transplantable bone and soft tissue tumors was 76.0 days and mean tumor growth index was 0.25. Serum LDH levels were as high as more than 5,000 Wrób. U for 8 of 12 lines tested. Serum ALP levels were normal for all tumors other than osteosarcoma. In mice transplanted with osteosarcoma, serum ALP levels were higher than 10 KAU for 8 of 13 lines tested. Pulmonary metastasis was seen in 5 of 9 osteosarcomas examined. For many of serially transplantable tumors, tumorigenicity was observed in nude mice by various transplantation routes including the subcutaneous, intraperitoneal and intravenous routes via the tail vain. Serially transplantable osteosarcomas were morphologically classified into three groups based on osteoid formation; those in which osteoid formation disappeared immediately, those in which osteoid formation decreased gradually, and those in which osteoid formation was unchanged or even increased. Osteoid was found for 6 of 13 lines examined. For 4 of the 6 tumors zone phenomenon was maintained during passages. For 2 lines among those in which osteoid disappeared, histological type was changed into quite another type from the original type of the tumor.

Animals↗
PubMed1985

Nanosecond fluorescence studies of noncovalent interaction of monomeric and dimeric intercalators with DNA.

The noncovalent interaction of 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2) and its derivatives, which are potent mutagens isolated from L-glutamic acid pyrolysate, with calf thymus DNA was studied by steady-state and nanosecond fluorescence spectroscopies. The fluorescence of these compounds exhibits static quenching by noncovalent interaction with DNA. Fluorescence lifetimes of the free and intercalated states of these compounds were determined to be 9-10 and 0.5-1 ns, respectively. The bisintercalative effect of the dimeric analogue of Glu-P-2, bis(Glu-P-2)spermine (2GP-SP), to DNA was also investigated. This 2GP-SP, which has two Glu-P-2 moieties at each end of spermine, indicates a strong intramolecular interaction exhibiting remarkable quenching of fluorescence spectrum and lifetime (tau = 3.5 ns) in the absence of DNA. In the presence of DNA, however, the 3.5-ns lifetime component of fluorescence disappeared, and a two-exponential decay of fluorescence (t = approximately 10 and 1.5 ns) was observed at a DNA concentration of more than approximately 0.001 mM P, while the solution containing a very dilute DNA concentration (less than or equal to 0.001 mM P) exhibits a three-component decay of fluorescence (1.5, 3.5, and approximately 10 ns). The potent bis intercalation of two moieties in 2GP-SP with an identical DNA molecule was suggested by the DNA-concentration dependence of these fluorescence lifetimes and their intensity.

Animals↗