PubMed Health⌕ Search

Biomedical subjects

F Murakami

Publications and source records attributed to F Murakami.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Two cases of coronary artery bypass grafting following radical mastectomy using bilateral internal thoracic arterial grafts].

We report two cases of coronary artery bypass grafting following radical mastectomy using bilateral internal thoracic arterial grafts. One was a 68-year-old woman with angina pectoris, and the other was a 71-year-old woman with old myocardial infarction. Dissection of the internal thoracic arterial pedicles from the chest wall was not so difficult in both cases. The pedicles had good patency and each free flow of them was enough. They had no postoperative complications. It may be a useful method to use the internal thoracic arterial grafts for a case of coronary artery bypass grafting after radical mastectomy.

Aged↗
PubMed1996

Emergency aortic arch replacement in a patient with idiopathic thrombocytopenic purpura.

We herein report the case of a 56-year-old man with idiopathic thrombocytopenic purpura who required an emergency aortic arch replacement. Intraoperatively, hemostasis was achieved using platelet transfusions. Postoperatively, the use of high-dose gamma-globulin therapy was able to maintain an adequate platelet count and good hemostasis.

Aortic Dissection↗
PubMed1996

Nafamostat mesilate reduces blood-foreign surface reactions similar to biocompatible materials.

BACKGROUND: Nafamostat mesilate (FUT-175) is a synthetic serine protease inhibitor that inactivates coagulation, fibrinolysis, and platelet aggregation. Nafamostat mesilate may suppress the blood-foreign surface reaction similar to biocompatible materials by blocking factor XIIa. METHODS: We performed an in vitro study of cardiopulmonary bypass (CPB) with fresh human blood among the following three groups: standard CPB sets (C), biocompatible CPB sets (B), and standard CPB sets with FUT-175 (10 mg/L) (F). A clinical study using these same CPB groups also was performed in 45 patients undergoing aortocoronary bypass operations (15 patients each). We injected FUT-175 at 40 mg/h during CPB. RESULTS: In the in vitro study, both groups B and F showed significantly lower levels of coagulation factors, thrombin-antithrombin III complex, fibrinopeptide A, beta-thromboglobulin, complement C3a, granulocyte elastase, and free hemoglobin than group C at the conclusion of the study. Thrombin-antithrombin III complex and free hemoglobin in group F also were lower than in group B. The platelet count remained at a higher level in group F than in the other groups. Separation of bradykinin was suppressed most significantly in group F. In the clinical study, group F also showed significantly lower levels of alpha 2-plasmin inhibitor plasmin complex and C3a than both groups C and B. There were minimal levels of free hemoglobin in group F. CONCLUSIONS: Nafamostat mesilate may contribute major beneficial effects toward conservation of blood during CPB and prevention of coagulopathy after CPB.

Benzamidines↗
PubMed1996

Guidance of circumferentially growing axons by netrin-dependent and -independent floor plate chemotropism in the vertebrate brain.

Netrin-1, a diffusible signal secreted by floor plate cells at the ventral midline of the vertebrate CNS, can attract ventrally migrating axons and repel a subset of dorsally migrating axons in the spinal cord and rostral hindbrain in vitro. Whether netrin-1 can act as a global cue to guide all circumferentially migrating axons is, however, unknown. Here, we show that netrin-1 can attract alar plate axons that cross the floor plate along its entire rostrocaudal axis. Dorsally directed axons forming the posterior commissure are, however, repelled by the floor plate by a netrin-independent mechanism. These results suggest that netrin-1 functions as a global guidance cue for attraction to the midline. Moreover, floor plate-mediated chemorepulsion may also operate generally to direct dorsal migrations, but its molecular basis may involve both netrin-dependent and -independent mechanisms.

Animals↗
PubMed1996

Morphology of individual axons in crossed corticorubral projections in developing cats and effects of partial denervation.

Ordered neuronal connections in mature brains are thought to be sculpted from initially diffuse projections by elimination of inappropriate projections and strengthening of appropriate ones. Although evidence suggests that neuronal activity plays a role in these processes, the mechanism behind the modification of neuronal connections remains obscure. To gain insight into the mechanisms of axonal elimination and projection strengthening, we examined the morphology of individual axons that were to be eliminated as well as the consequences of partial denervation. While corticorubral projections in adult cats are thought to be uncrossed, early in postnatal development and after early unilateral lesions to the sensorimotor cortex, however, a significant amount of crossed corticorubral projections occurs. We examined the morphology of individual corticorubral axons in fetal cats and kittens from embryonic day 59 to postnatal day 48 and those that had received early unilateral lesions to the cortex, by serial reconstruction of Phaseolus-vulgaris-leucoagglutinin- or biocytin-labeled axons. For about 2 weeks during pre- and postnatal development, crossed axons remained simple in morphology, with few branches. Thereafter, they showed an increase in branch number, but then began to show fewer branches again. Axons and their collaterals were found in nonrestricted areas of the red nucleus (RN) throughout the period of observation, indicating that axons can sit at an inappropriate target for weeks but fail to ramify. In contrast, crossed corticorubral axons in kittens with cortical lesions showed terminal-arbor-like structures in the RN region that are in mirror symmetry to topographically appropriate areas in the ipsilateral RN, although some showed simple morphology without arbors. These complicated forms of morphology of individual axons during development and after partial denervation may not be explained by a simple activity-dependent mechanism.

Animals↗
PubMed1996

[Cytotoxic action of monoclonal antibodies OC125 and SH-9 on ovarian cancer cell lines].

A large number monoclonal antibodies (Mo-Abs) to neoplasms have been utilized as diagnostic tools, but they have not yet been fully characterized from the biological point of view. Antibody-dependent cellular cytotoxicity, complement dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) were investigated in Mo-Abs OC125 and SH-9 (IgG1) to ovarian tumor cell lines SHIN-3, MN-1, KEN-3 and EC by MTT assay in vitro. OC125, but not SH-9 showed prominent CDC activity against SHIN-3 and MN-1 cell lines. CDC activity was induced against OC125 and SH-9, when a guinea pig complement was used. Furthermore, ADCC, activity was significant against SHIN-3, MN-1, OC125 and SH-9, but not against KEN-3 or EC. In summary, OC125 had both CDC and ADCC activity, but SH-9 did not. We concluded that the epitope on CA125 antigen varied in OC125 and SH-9, and each of epitope in Mo-Abs may have a different biofunction.

Animals↗
PubMed1996

[Transitions of each inhibitor in a patient with lupus anticoagulant and anti-prothrombin antibody].

In a 2-year-old girl showing purpura on her legs after administration of antibiotics, marked prolongation of activated partial thromboplastin time(APTT) and prothrombin time was noted. Circulating anticoagulants were demonstrated by the failure to correct APTT on neutralization test. A lupus anticoagulant(LA), one of the circulating anticoagulants, was detected by rabbit brain phospholipid neutralization procedure and platelet neutralization procedure. On crossed immunoelectrophoresis, the abnormal prothrombin peaks with reduced electrophoretic mobilities were considered prothrombin/prothrombin-antibody complexes because pretreatment with anti-human IgG serum caused their disappearance. This prothrombin-antibody seemed to be another circulating anticoagulant. The anti-prothrombin-antibody reduced prothrombin activities in the circulating blood of the patient to 20 approximately 30% of normal and the condition persisted for two weeks resulting in the purpura which occurred during that period. After two months, APTT was restored to normal following the disappearance of LA.

Animals↗
PubMed1996

[Administration method and recurrence-preventing effect of medroxyprogesterone acetate (MPA) as a postoperative adjuvant endocrine therapy for stage III breast cancer. Kitakyushu Collaborative Study Group for Breast Cancer].

By a collaborative study undertaken by 11 medical institutions in the Kita-Kyushu area, we evaluated the clinical efficacy of the combination of medroxyprogesterone acetate (MPA) and Tamoxifen (TAM) as a postoperative adjuvant endocrine therapy for Stage III breast cancer. First, 1 course of CAF therapy was administered; then, in combination with the basic therapy of 5-FU 200 mg/day p. o. for 3 years, ER (+) patients were treated with either 2-week sequential therapy of TAM (30 mg/day) and MPA (800 mg/day) or TAM (30 mg/day), and ER (-) patients received either MPA (800 mg/day) or 5-FU alone. Neither survival nor disease-free rates of the 92 analyzable patients were different between these treatment groups. Furthermore, the blood levels of MPA and cortisol had no correlation with survival and disease-free periods. We studied the effect of MPA on the natural inhibitors of blood coagulation, but found no difference from the result in healthy adults. It was, however, shown that MPA had a bone marrow-protecting effect.

Adult↗
PubMed1996

An alternative elastase-mediated degradation of fibrinogen and fibrin observed in a patient with herpes simplex encephalitis and pneumonia.

A 74-year-old female developed pneumonia following herpes simplex encephalitis. Her white blood cell counts reached 28,400/microliters, about 90% of which consisted of granulocytes. The polymorphonuclear (PMN) elastase/alpha 1-antitrypsin complex levels increased and reached the maximum of 5,019 ng/ml, indicating the release of a large amount of elastase derived from the granulocytes. The mechanism of PMN elastase release was most likely to be granulocyte destruction associated with phagocytosis. The cleavage of fibrinogen and fibrin by PMN elastase, independent of plasmin, was indicated by the presence of the fragments in immunoprecipitated plasma from the patient corresponding to elastase-induced FDP D and DD fragments and the absence of fragments corresponding to plasmin-induced FDP D and DD fragments on SDS-PAGE. These findings suggested that the large amount of PMN elastase released from the excessive numbers of granulocytes in this patient with herpes simplex encephalitis and pneumonia, induced the cleavage of fibrinogen and fibrin without the participation of plasmin.

Aged↗
PubMed1996

[Mediastinitis treated by an omental transfer following CABG using the right gastroepiploic arterial graft].

We treated four cases with mediastinitis after coronary artery bypass grafting using the right gastroepiploic artery. These four patients were treated with the pedicled omentum. Omental transfer was successful in three cases. After the harvest of the right gastroepiploic arterial graft, the residual omentum was viable. The residual omentum was applicable for the treatment of mediastinitis.

Aged↗
PubMed1995

Prenatal development of cerebrorubral and cerebellorubral projections in cats.

Cerebrorubral (CR) and cerebellorubral (CBR) afferents are localized to distal dendrites and somata of red nucleus (RN) neurons, respectively, in adult cat. To test if this synaptic site segregation is established by a sequential arrival of the two afferents, the development of CR and CBR projections was studied. CR axons arrived in the RN at embryonic day (E) 50 or 51, while CBR axons entered the RN before E35. These results suggest the possibility that arrival of CBR axons before CR axons leads to the segregation of synaptic sites.

Afferent Pathways↗
PubMed1995

Perinatal development of action potential propagation in cat rubrospinal axons.

1. The development of action potential conduction was studied by intracellular recording of antidromic spikes in cat rubrospinal cells. 2. The distance between the C1 and L1 spinal segments increased linearly from 5.6 cm at embryonic day (E) 59 to 9.8 cm at postnatal day (P) 30. 3. The conduction time from the C1 segment to the rubrospinal neuron soma, estimated from antidromic spike latency evoked by stimulation of the C1 segment, decreased rapidly prior to birth and then slowly thereafter. This coincided with a reduction in conduction time variation between cells. 4. The conduction time from the red nucleus to the L1 segment followed a similar time course during development. The conduction time reached the adult value by P30, at which time the spinal cord is only half the adult length. 5. The conduction velocity between the C1 and L1 segments increased monotonically between E59 and P30, from a low of 1 m s-1 to a maximum of 34 m s-1. 6. The rise time of rubrospinal neuron somadendritic spikes followed a developmental time course similar to that for conduction time. 7. Myelination of rubrospinal axons, as judged by the presence of myelinated segment spikes, began to occur prior to E59. 8. These findings suggest that development of action potential propagation in rubrospinal cells can be divided into an early and a late stage: conduction time reaches the adult value during the early stage, i.e. by the first postnatal month, and is maintained during the late stage. We propose that myelination, axon diameter increase and maturation of membrane properties act to reduce conduction time to adult values during the early stage, while a proportional increase in fibre diameter with axonal length results in a constant conduction time during the late stage.

Action Potentials↗
PubMed1995

Growth cones of dorsal root ganglion but not retina collapse and avoid oligodendrocytes in culture.

Axons in the central nervous system of mature mammals generally fail to regenerate following injury. Although the reason for this regenerative failure remains unknown, several lines of evidence suggest that it is due to nonpermissiveness of oligodendrocytes for axonal elongation. However, most of the in vitro experiments carried out so far used neural-crest-derived peripheral neurons to test the permissiveness of oligodendrocytes, although studying the interactions between central neurons and oligodendrocytes is crucially important for elucidating their roles in vivo. In this study we cultured retinas and dorsal root ganglia of the chick embryo with oligodendrocytes obtained from postnatal rat spinal cord and performed time-lapse analysis. Oligodendrocytes were identified with galactocerebroside antibody. Retinal growth cones readily grew over oligodendrocytes, while growth cones of the dorsal root ganglion collapsed and grew away on contacting the oligodendrocytes. Correspondingly, neurite-free areas centered by oligodendrocytes were formed behind growth cones in DRG-oligodendrocyte but not in retina-oligodendrocyte co-culture. These observations suggest the possibility that responsiveness of growth cones to oligodendrocytes is dependent on neuronal type.

Animals↗
PubMed1995

Mitral valve replacement via right thoracotomy after coronary arterial grafting.

Mitral valve replacement was performed through a right thoracotomy using femorofemoral bypass under profound systemic hypothermia in a 62-year-old man who had undergone coronary artery bypass grafting using both internal thoracic arteries. The right thoracotomy approach minimizes the risk of injury to the arterial grafts, and deep hypothermia obviates the need to interrupt the grafts to administer cardioplegia. This technique provides excellent exposure of the mitral valve while minimizing the operative risk.

Bioprosthesis↗
PubMed1995

Guidance of cerebellofugal axons in the rat embryo: directed growth toward the floor plate and subsequent elongation along the longitudinal axis.

To elucidate guidance mechanisms of brain commissural axons, we examined the navigation of cerebellofugal axons. Axons were labeled by implantation of the fluorescent tracer Dil into the cerebellar plate (CP) of fixed, flat whole-mount embryonic rat brain. Axons initially grew straight toward the ventral midline floor plate (FP) in the rostral hindbrain and then, after crossing it, made a right-angled turn to grow either caudally or rostrally along the longitudinal axis. In collagen gel culture, CP axons showed directed growth toward both FP explants and heterologous cells expressing netrin-1, a FP-derived chemoattractant for spinal commissural axons. These results suggest that CP axons are guided to the midline by FP-derived chemoattractant(s) and then reoriented, possibly by another guidance cue, for longitudinal extension. Considering that the basic structures of the neural tube, including the FP, extend up to the caudal diencephalon, these results suggest that common guidance mechanisms operate for ventrally decussating commissural axons in both the brain and spinal cord.

Animals↗
PubMed1995

Floor plate chemoattracts crossed axons and chemorepels uncrossed axons in the vertebrate brain.

In the bilaterally symmetrical vertebrate CNS, all developing axons must choose between remaining on the same side of the midline or growing across it. The mechanism underlying this axonal pathfinding is, however, poorly understood. Here we demonstrate that the ventral midline floor plate (FP) chemorepels two types of ipsilaterally projecting axons, one from the alar plate and another from the basal plate in the mesencephalon. We further demonstrate that the FP chemoattracts contralaterally projecting myelencephalic as well as metencephalic axons. The FP at all axial levels displayed both chemoattractive and chemorepellent activities, suggesting that FP chemoattraction and chemorepulsion may be at work throughout the neuraxis. Chemotropic guidance by the FP may therefore play a key role in the establishment of neuronal projection laterality.

Animals↗