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Biomedical subjects

M Usui

Publications and source records attributed to M Usui.

At least 307 records · Page 17Linked to original sources
PubMed1985

Effect of fluorocarbon perfusion upon the preservation of amputated limbs. An experimental study.

The present study was undertaken to investigate the effect of fluorocarbon on the preservation of an amputated limb. The hind limbs of dogs were completely amputated through the mid-thigh; some were perfused with fluorocarbon, others with lactated Ringer's solution and some were not perfused at all. After six hours of ischaemia, all the limbs were replanted. Perfusion with fluorocarbon had an inhibitory effect on the anaerobic metabolism of an amputated limb, thus increasing the survival rate. Leakage of creatine phosphokinase from the replanted limb also was inhibited by perfusion with fluorocarbon. These effects were more striking when the amputated limb was perfused continuously rather than intermittently and when it was preserved in iced water rather than at room temperature; these measures helped to prevent replantation toxaemia and to preserve muscle function.

Amputation, Surgical↗
PubMed1985

[The pathomechanism underlying ischemic brain edema: the role of Na+, K+-ATPase of the brain microvessels].

In the present study, the anti-edema effect of AVS [1,2-bis (nicotineamide)-propane] was evaluated using the cat MCA occlusion model with or without recirculation. In the prolonged ischemia (PI) group, cortical edema as assessed by the changes in specific gravity, developed in those cortical areas where the mean 1-CBF was less than 25-30 ml/100 g/min during MCA occlusion (4 hours). In the recirculation group (2 hours' ischemia followed by 2 hours' recirculation: RC group), the ischemic threshold for edema development was almost the same as in the PI group. In both groups, the drop in cortical specific gravity was significantly suppressed by AVS. Regarding the time-course of 1-CBF, there was no difference between the PI-AVS-treated and PI-saline-treated groups. In the RC group, however, the postischemic hypoperfusion was significantly ameliorated by AVS. Based on the present and previous data showing the antiedema effect of AVS, the mechanism of action of AVS was discussed in relation to the pathomechanism underlying ischemic brain edema. Our new concept of ischemic brain edema is briefly stated below. Related in vitro studies have shown the followings: (i) the influx of sodium not of proteins is the principal cause of ischemic brain edema: (ii) the eicosanoid synthetic capacity of the brain microvessel (MV) is increased simultaneous to edema development (iii) an elevation in the level of hydroperoxides enhances the activities of Na+, K+-ATPase as well as the arachidonate cascade of MV. These data suggest that free fatty acids and free radicals liberated following cerebral ischemia stimulate the activity of the MV-Na+, K+-ATPase, which results in increased sodium influx across the BBB. AVS was shown to scavenge hydroxyl radicals and to inhibit the stimulatory effects of a lipid hydroperoxide (15-HPAA) on the activities of Na+, K+-ATPase and the arachidonate cascade of the MV. These actions of AVS may be linked to its antiedema effect.

Animals↗
PubMed1985

Characterization of the accessory cells involved in suppressor T cell induction.

The ability of UV-treated splenic adherent cells (SAC) to induce T cell-mediated immunity and suppressor T cells was analyzed in the 4-hydroxy-3-nitrophenyl acetyl (NP) system. UV irradiation of 0.88 KJ/m2 decreased the capacity of NP-coupled SAC to induce delayed-type hypersensitivity (DTH) responses by about 50%. The ability of uncoupled UV-treated SAC to induce allogeneic DTH response was also imparied, indicating that UV-treated SAC are inefficient at inducing DTH in these systems. TS1 induction by UV-treated NP-SAC was evaluated TS1 induction by UV-treated NP-SAC was evaluated by using adherent cells that were subjected to the same dose of UV irradiation that impaired DTH induction. Intravenous administration of 10(3) or 10(4) UV-treated NP-coupled SAC induced TS1 cells with the same efficiency as non-UV-irradiated cells. The TS1 cells induced in this fashion were antigen specific. Furthermore, to establish that the antigen was not reprocessed by the host, I-J-mismatched, UV-treated NP-SAC were unable to induce TS1 cells. The population of antigen-presenting cells responsible for TS1 induction appear to express both I-A and I-J determinants. TS2 induction by UV-treated accessory cells was also analyzed. TSF1 inducer suppressor factor was pulsed onto graded numbers of either normal or UV-treated adherent cells. The same levels of antigen-specific suppression were induced with normal and UV-treated cells. Finally, TS3 induction by UV-treated NP-SAC was analyzed. UV-treated and normal NP-SAC (3 X 10(3] induced antigen-specific suppression of NP DTH responses. I-J-mismatched, UV-treated NP-SAC failed to induce suppression, suggesting that the hapten was not reprocessed by the host under these experimental conditions. The accessory cell population responsible for TS3 induction appears to express both I-A and I-J determinants. Thus, there are at least two functional distinctions between the antigen-presenting cells that induce immunity vs those that induce suppressor cells. First, UV treatment selectively impairs the antigen-presenting cells, which activate the positive limb of the immune response. Second, I-J determinants appear to be specifically associated with the SAC, which induce suppressor T cells. Although these criteria can be used to distinguish the accessory cells involved in suppressor cell pathways from those controlling helper T cell induction, there were no discernible phenotypic differences among the accessory cells that induce the TS1, TS2, and TS3 subsets.

Animals↗
PubMed1985

[Human adult left atrial volume estimated by M-mode echocardiography].

There are few systematic reports of the regression equation for humans, for estimating left atrial volumes from the anteroposterior left atrial dimensions measured by M-mode echocardiography (LADAP). In addition, several pitfalls were inherent in the M-mode method. In view of these pitfalls, we estimated the anteroposterior left atrial dimensions by directing the ultrasonic beam toward the "center" of the left atrium under the guidance of two-dimensional echocardiography. Simultaneously, we estimated left atrial volumes from anteroposterior and left lateral biplane left atrial angiocardiograms using a film changer at three frames per sec. The maximum elapsed time between the echocardiographic and angiocardiographic studies was two days. Left atrial volumes were calculated using the method of Sauter et al. Maximum left atrial volume was calculated at the end of the T wave. The results were as follows: For phantom experiments, a cylindrical container with varying amounts of contrast material was tested by biplane angiography using a film changer. The actual volume (x) and the calculated volume (y) were in good agreement with the regression equation; y = 1.05x-0.1 (r = 0.99, p less than 0.001, n = 6). The anteroposterior left atrial dimension in M-mode echocardiography (LADAP: x axis) and left atrial volume (ml) angiocardiographically obtained (y axis) showed the curvilinear regression equation; y = 1.4x3+23 (r = 0.83, p less than 0.01, n = 19). The relation between the left atrial cross-sectional area (cm2) obtained from the left ventricular long-axis view by two-dimensional echocardiography (x axis) and the left atrial volume (ml) by angiocardiography using a film changer (y axis) showed the regression equation; y = 1.2x1.5+17 (r = 0.82, p less than 0.01, n = 14). As a preliminary study, we calculated left atrial volume (LAVcine) for five patients by performing biplane cineangiocardiography at 50 frames per sec. The results were nearly the same as those obtained using a film changer. In summary, the derived equation predicts left atrial volume using M-mode echocardiography with considerable accuracy.

Adolescent↗
PubMed1985

[A histological study on osteosarcoma. Part II: The mode of local extension of osteosarcoma].

The survival rate of patient with osteosarcoma has been increasing, owing to the development of adjuvant chemotherapy. Recently, the limb saving procedure in osteosarcoma has been attempted in many countries. Although we need knowledge about the mode of local extension of osteosarcoma in the planning of this surgery, there are few reports concerning the matter. The purpose of this paper is to make clear, morphologically, how tumor tissue extends across the epiphyseal plate, periosteum and bone marrow. The materials were 26 amputated extremities of osteosarcoma which had not received any chemotherapy or radiotherapy. Paraffin embedded macrosections were prepared and stained with HE and Masson stain. When epiphyseal plate was open or closing, 13 out of 14 cases (93%) showed transphyseal extension of tumor. Tumor extension along the vessels at the center of the plate and the epiphyseal artery was most common. Transmedullary extension showed three different types, infiltrative type (18 cases), lobular type (5 cases), and "skip" type (one case). None had capsule or pseudocapsule surrounding the tumor. As to the relationship between periosteal reaction and tumor involvement of cortex or medulla, periosteal reaction was located more proximally than cortical or medullary involvement in some cases. In other cases, however, cortical or medullary involvement was located more proximally than periosteal reaction. The gaps between the tips of the periosteal reaction and cortical or medullary involvement ranged from 0.5 to 1.5 cm. In the transperiosteal extension, it was confirmed that tumor cells had invaded the periosteum along the vessels penetrating the periosteum.

Adolescent↗
PubMed1985

[Identification of 11-HETE in the rat brain and its relevancy to ischemic cerebral edema].

Eicosanoids are thought to be important in the pathogenetic mechanism of ischemic brain damage. But little is known about lipoxygenase products and their roles in brain. In the present study, lipoxygenase metabolism in the brain and its relevancy to ischemic brain edema were studied using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The rat middle cerebral artery (MCA) occlusion model was used because the time course of ischemic edema formation has been well known. The rat brain was fixed by in situ freezing 24 and 72 hours after MCA occlusion, and removed. Identification and quantitative analysis of hydroxyeicosatetraenoic acids (HETEs) in normal and ischemic brain homogenates was performed by HPLC and GC-MS. The rat brain was divided into the microvessel (MV) fraction and the rest. Then the same analysis was carried out in the both fractions obtained from the normal rat brain. Only 11-HETE was detected in the normal and ischemic brain. Quantitatively, normal brains contained 1288 +/- 66 (mean +/- SE) of 11-HETE ng/g wet weight, while the hemispheres rendered ischemic for 24 and 72 hours after MCA occlusion contained 1101 +/- 48, and 1663 +/- 147, respectively. The 11-HETE content was significantly increased 72 hours after MCA occlusion (p less than 0.05). The MV fraction of rat brain contained 11-HETE (653 ng/mg protein) ten times as much as the other fraction. The identification of 11-HETE in the rat brain is a new finding.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Neutrophilic nodules in the intestinal walls of Japanese monkeys associated with the neutrophil chemotactic activity of larval extracts and secretions of Oesophagostomum aculeatum.

High neutrophil chemotactic activity was detected in the culture medium from Oesophagostomum aculeatum larvae in vitro using blind-well chambers with Millipore filters, and guinea pig leucocytes as indicator cells. Neutrophil chemotactic activity was also detected in the extract from larval worms in a dose dependent fashion. This activity was detected in the low molecular weight fractions adjacent to a sodium chloride marker by gel filtration on Sephadex G200. These results were further confirmed with monkey neutrophils. The possible role of this activity in the formation of granulomatous lesions rich in neutrophils found in O aculeatum infections in the Japanese monkey is discussed.

Animals↗
PubMed1985

Metabolic and histologic changes in the ischemic muscles of replanted dog legs.

The sequential and histologic changes occurring in muscles from ischemia were investigated in dogs. The left hind limbs were amputated, and recirculation was established after preserving them either in ice water or at room temperature for six to 12 hours. Slight leakage of the muscle enzymes creatine phosphokinase (CPK), mitochondrial glutamic oxaloacetic transaminase (GOT-m), and lactate dehydrogenase (LDH) into the recirculated venous blood occurred in specimens preserved in ice water for six hours, but there was a marked increase in enzyme leakage in the other groups. Histologic muscle changes consisted of cell swelling and separation of the sarcoplasm from the endomysium. Electron microscopy revealed widening of the myofibrillar spaces, a virtual absence of glycogen granules, and degeneration of mitochondria. These results support the clinical practice that the amputated extremities must be preserved in ice water and that blood recirculation should be initiated within six hours of amputation.

Amputation, Surgical↗
PubMed1985

Cubitus varus deformity following supracondylar fracture of the humerus. A method for measuring rotational deformity.

Cubitus varus following supracondylar fracture of the humerus in children consists of varus, hyperextension, and internal rotation deformities of the distal bone fragment of the humerus. There has been no simple clinical method of measuring internal rotation deformity. The authors report here on a method of accurately measuring the internal rotation of the shoulder in a position with the elbow at 90 degrees flexion on the back and the shoulder held at the maximum extension. When a patient with developing cubitus varus attempts to rotate his shoulder internally, there is an apparent increase in the degree of internal rotation at the shoulder of the fractured side. The mean value of the angle formed between the horizontal plane of the back and the mid-line of the forearm was approximately 0 degrees in 217 normal children, whereas an increase of 35 degrees was seen in seven children with cubitus varus. When this angle was corrected successfully, the angle after surgical correction became approximately 0 degrees. In the treatment of cubitus varus deformity, it is necessary to simultaneously correct three-dimensional deformities.

Child↗
PubMed1985

Delayed rupture of a flexor tendon secondary to fracture of the lunate.

Attritional ruptures of flexor tendons following carpal fractures are rare. The authors report a case of delayed rupture of flexor digitorum profundus of the index finger caused by fracture of the lunate. To our knowledge, this is the first report of such a tendon rupture following a fracture of the lunate.

Fractures, Bone↗
PubMed1985

Localization of S-antigen under various conditions of light or dark adaptation in the rabbit.

The localization of the S-antigen was studied by electron microscopy in the rabbit eye, under three conditions of adaptation: A) 24-hour dark adaptation, B) 24-hour dark adaptation and 1.5-hour light adaptation and C) light adaptation for 30 hours. The Fab' fraction of the IgG of rabbit against the swine S-antigen was labeled with horseradish peroxidase (HRP) and was used as the marking antibody. In Group A, the HRP reaction products indicating the S-antigen were found mainly in the disk and plasma membranes of the outer segments of the photoreceptor cells. The reaction products were also found diffusely in the cytoplasm of the inner segment with the exception of the mitochondria and nucleus. In Group B, the phagosomes were found surrounded by the multilayered microvilli of the retinal pigment epithelial (RPE) cells; the reaction products were scarcely found in the phagosomes but were seen in the microvilli. Some weak reaction products were also encountered in the cytoplasm of the RPE cells. In Group C, after 30-hour light adaptation, many phagosomes were found but they contained almost no reaction products. However, the microvilli of the RPE cells surrounding the phagosomes showed a fair amount of the reaction products. The cytoplasm of the RPE cells contained abundant reaction products, particularly in the area of the basal infoldings. The reaction products were also seen in the Bruch's membrane and the endothelial cells of the choriocapillaris. It was thought that the S-antigen is taken up by the RPE during phagocytosis of the shed outer segments and is transported to the choriocapillaris.

Adaptation, Physiological↗
PubMed1984

The occurrence of soft tissue sarcomas in three siblings with Werner's syndrome.

Werner's syndrome, a relatively rare and autosomal recessive disorder, is well known to be characterized by a high frequency of malignant neoplasm. The occurrence of familial neoplasm in patients with this condition, however, has been recorded only once before in the literature. Reported are the findings with regard to the occurrence of sarcomas in three siblings with Werner's syndrome. Two of the current three cases were of malignant fibrous histiocytomas, one in a 36-year-old man and one in a 32-year-old woman. The other case was of a leiomyosarcoma in a 26-year-old man. Two of the patients died of the tumors, although the third is still alive. The exact cause of the high incidence of malignant tumor in this family remains unknown, as is still so in other cases of Werner's syndrome.

Adult↗
PubMed1984

Thumb reconstruction by free sensory flaps from the foot using microsurgical techniques.

Four types of thumb reconstruction using microsurgical technique were performed in 23 cases; the dorsalis pedis flap, hemipulp (first web space) flap, wrap around flap, and toe-to-thumb transfer. The selection of which free sensory flaps should be used for thumb reconstruction is discussed. The selection of sensory nerves to be sutured as the donor and recipient nerves is based on the results of restoration of sensibility after free sensory flap transfers.

Adolescent↗
PubMed1984

Leukocyte accumulation in sparganosis: demonstration of eosinophil and neutrophil chemotactic factors from the plerocercoid of Spirometra erinacei in vivo and in vitro.

In order to determine whether the plerocercoid of Spirometra erinacei itself has eosinophil and neutrophil chemotactic factors, in vivo and in vitro examinations were carried out. We could observe large numbers of eosinophils and neutrophils which accumulated at the injection site of normal guinea pig skin following intradermal injection of soluble extract of plerocercoids of S. erinacei. At 1 hour after the injection, neutrophils appeared at the site, and the cell number reached its peak at 4 hours. Eosinophils appeared rather later than neutrophils (at 2-4 hours), and the number of cells reached its peak at 8 hours after the injection. Eosinophil and neutrophil chemotactic activities were also confirmed in an in vitro system by using a blind-well chemotaxis chamber with a Millipore filter in dose dependent fashion. An eosinophil chemotactic factor (ECF) with molecular weight of approximately 15,000, and two different neutrophil chemotactic factors, one of about same molecular weight as the ECF and the other of low molecular weight, were demonstrated by gel filtration on Sephadex G-200. Furthermore, it was confirmed that those factors were released from parasite by the detection of intensive eosinophil and neutrophil chemotactic activities in the culture supernatants containing plerocercoids.

Animals↗
PubMed1984

Eosinophil and neutrophil chemotactic activities of adult worm extracts of Schistosoma japonicum in vivo and in vitro.

Large numbers of eosinophils and neutrophils attracted to the soluble extract of Schistosoma japonicum adult worms (SjAW-ext) were detected at the injection site of normal guinea pig skin. Eosinophil and neutrophil chemotactic activities were also confirmed in in vitro assay by using blind-well chambers with Millipore filters in dose-dependent fashion. Two components of SjAW-ext showed eosinophil chemotactic activity; one was in the high molecular weight fraction (JAE-H), estimated to be more than 440,000 daltons, the other in the low molecular weight fraction (JAE-L) obtained by Sephadex G-200 gel filtration. High neutrophil chemotactic activity was detected in the JAE-L. These eosinophil and neutrophil chemotactic activities were also detected in culture fluid of S. japonicum adult worms. Eosinophil chemotactic factor (ECF) of JAE-H was stable to heating (100 C, 30 min) and pronase digestion, but completely destroyed by periodate oxidation. It is suggested that the ECF of JAE-H is a glycoprotein. JAE-L was also stable to heating (56 and 100 C, 30 min) and pronase digestion for eosinophil chemotaxis. Possible roles of those activities in schistosome infections are discussed.

Animals↗