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Biomedical subjects

Y Nagase

Publications and source records attributed to Y Nagase.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Safety and indication of open heart surgery without blood transfusion for congenital cardiac defects in infants].

Between January 1994 and June 1997, 16 cases of ventricular septal defect (VSD) and endocardial cushion defect (ECD) with pulmonary hypertension (PH), each weighing from 5 to 9 kg, underwent definitive surgery at Matsudo Municipal Hospital. We classified them into 2 groups; Group N: 8 cases without blood transfusion, Group H: 8 cases with blood transfusion. Cardiopulmonary bypass (CPB) system was a closed circuit and priming volume was 370 to 500 ml. There was no difference between the 2 groups in operative age, body weight, preoperative state, operation time, CPB time, aortic cross clamp time, bleeding and postoperative state. In Group N, CPB blood was returned to the patient as soon as possible after CPB was weaned, and postoperative hemodynamics were stable in both groups. In Group N, hematocrit (Ht) values were consistently lower than in Group H, from initiation of CPB to leaving the hospital. To accomplish safe CPB, we measured systemic venous oxygen saturation (SvO2). In 6 cases of Group N, SvO2 during rewarming was 48.1 +/- 16.0% and Ht value was 13.2 +/- 1.5%. It is thought that the safe CPB could be conducted in Group N. In addition, in Group N, respiratory index showed better values than in Group H during the postoperative period. It is thought that CPB without blood transfusion may be favorable to prevent lung injury after CPB. Retrospectively, it is thought that, to accomplish safe CPB without blood transfusion, preoperative Ht values of over 30% are desirable in patients weighing 6 kg and those of over 35% are desirable in patients weighing 5 kg.

Blood Transfusion↗
PubMed1998

[Open heart surgery without blood transfusion for cyanotic congenital cardiac defects].

Between November 1994 and January 1997, 42 cases of cyanotic congenital cardiac defects underwent definitive surgery at Matsudo Municipal Hospital. We evaluated 30 cases, each weighing from 7 to 20 kg. The procedures were performed at the age of 9 months to 6 years (mean age-2.4 years). The body weights were 7.7 to 20 kg (mean weight-11.4 kg). The preoperative diagnoses were Tetralogy of Fallot (TOF) in 19 cases, Fontan candidates in 6 and the others in 5. We classified them into 3 groups; Group A--15 cases were completed with non-blood transfusion, Group B--8 cases used only plasma protein fraction and Group C--7 cases used blood transfusion. Cardiopulmonary bypass (CPB) system is a semi-closed circuit and priming volume is 400 to 600 ml. There is no difference among the 3 groups in operative age, body weight, operation time, CPB time, aortic cross clamp time, bleeding and postoperative state. The same results were obtained in minimum base excess and urine output during CPB and the changes of hematocrit and total protein. In Groups A and B, CPB blood was returned to the patient as soon as possible after CPB was weaned, but in Group C, blood transfusion was performed without the return of CPB blood. In all groups, hemodynamics were stable. Retrospectively, it is thought that blood transfusion was not necessary in Group C and the use of the plasma protein fraction was not needed in Group B. In conclusion, the open heart surgery can be performed safely without blood transfusion for cyanotic congenital cardiac defects.

Blood Transfusion↗
PubMed1998

Combined anterior thigh flaps and vascularised fibular graft for reconstruction of massive composite oromandibular defects.

Six massive, composite oromandibular defects were reconstructed using combined anterior (anterolateral and anteromedial) thigh flaps and vascularised fibular graft in bridge or chimeric fashion. Except for minor dehiscence in one case and infection in another, all flaps survived without complication. Anterior thigh flaps provide large-calibre, long vascular pedicles while derivative branches from the lateral circumflex femoral system facilitate simultaneous transplantation of multiple components. Because the pedicle of the vascularised fibular graft is of insufficient length, the lateral circumflex femoral vessels provide a remote vascular source as a flow-through vascular conduit. A combined flap using the lateral circumflex femoral system is considered to be most suitable for reconstruction of through-and-through defects of the head and neck. The authors describe the advantages of this method and the detailed anatomy of the cutaneous perforators of the anterior thigh flaps.

Adult↗
PubMed1998

[Management for the postoperative mediastinitis in infancy].

Postoperative mediastinitis is a rare but life-threatening complication after cardiac surgery. We successfully managed three infants with postoperative mediastinitis. When the postoperative mediastinitis was suspected, intravenous infusion of antibiotics (Vancomycin) and local irrigation were performed. The reoperation for closure was planned when the value of c-reactive protein decreased to 1.0-2.0. An application of a pectoral musculocutaneous flap was effective when the sternum was destroyed by infection.

Anti-Bacterial Agents↗
PubMed1997

Ultrastructural observations of synaptic connections of vibrissa afferent terminals in cat principal sensory nucleus and morphometry of related synaptic elements.

Previous work suggests that slowly adapting (SA) periodontal afferents have different synaptic arrangements in the principal (Vp) and oral trigeminal nuclei and that the synaptic structure associated with transmitter release may be related directly to bouton size. The present study examined the ultrastructures of SA and fast adapting (FA) vibrissa afferents and their associated unlabeled axonal endings in the cat Vp by using intra-axonal labeling with horseradish peroxidase and a morphometric analysis. All SA and FA afferent boutons contained clear, round, synaptic vesicles. All the FA and most SA boutons were presynaptic to dendrites, but a few SA boutons were axosomatic. Both types of bouton were frequently postsynaptic to unlabeled axonal ending(s) containing pleomorphic, synaptic vesicles (P-ending). The size of labeled boutons was larger in FA than SA afferents, but the size of dendrites postsynaptic to labeled boutons was larger for SA than FA afferents. Large-sized FA and SA boutons made synaptic contacts with small-diameter dendrites. The size of FA and SA boutons was larger than that of their associated P-endings. A morphometric analysis made on the pooled data of SA and FA boutons indicated that apposed surface area, active zone number, total active zone area, vesicle number, and mitochondrial volume were highly correlated in a positive linear manner with labeled bouton volume. These relationships were also applicable to unlabeled P-endings, but the range of each parameter was smaller than that of the labeled boutons. These observations provide evidence that the two functionally distinct types of vibrissa afferent manifest unique differences but share certain structural features in the synaptic organization and that the ultrastructural "size principle" proposed by Pierce and Mendell ([1993] J. Neurosci. 13:4748-4763) for Ia-motoneuron synapses is applicable to the somatosensory system.

Adaptation, Physiological↗
PubMed1997

Serotonergic axonal contacts on identified cat trigeminal motoneurons and their correlation with medullary raphe nucleus stimulation.

The innervation of the trigeminal motor nucleus by serotonergic fibers with cell bodies in the raphe nuclei pallidus and obscurus suggests that activation of this pathway may alter the excitability of trigeminal motoneurons. Thus, we recorded intracellular responses from cat jaw-closing (JC) andjaw-opening (JO) alpha-motoneurons evoked by raphe stimulation and used a combination of intracellular staining of horseradish peroxidase (HRP) and immunohistochemistry at the light and electron microscopic levels to examine the distribution of contacts made by serotonin (5-HT)-immunoreactive boutons on the two motoneurons types. Electrical stimulation applied to the nucleus raphe pallidus-obscurus complex induced a monosynaptic excitatory postsynaptic potential (EPSP) in JC (masseter) alpha-motoneurons and an EPSP with an action potential in JO (mylohyoid) alpha-motoneurons. The EPSP rise-times (time to peak) and half widths were significantly longer in the JC than in the JO motoneurons. The EPSPs were suppressed by systemic administration of methysergide (2 mg/kg). Six JC and seven JO alpha-motoneurons were well stained with HRP. Contacts were seen between 5-HT-immunoreactive boutons and the motoneurons. The JC motoneurons received a significantly larger number of the contacts than did the JO motoneurons. The contacts were distributed widely in the proximal three-fourths of the dendritic tree of JC motoneurons but were distributed on more proximal dendrites in the JO motoneurons. At the electron microscopic level, synaptic contacts made by 5-HT-immunoreactive boutons on motoneurons were identified. The present study demonstrated that JC motoneurons receive stronger 5-HT innervation, and this correlates with the fact that raphe stimulation caused larger EPSPs among these neurons than among JO motoneurons.

Animals↗
PubMed1997

Organization of the descending projections from the parabrachial nucleus to the trigeminal sensory nuclear complex and spinal dorsal horn in the rat.

To clarify direct descending projections from the parabrachial nucleus (PB) to the trigeminal sensory nuclear complex (TSNC) and spinal dorsal horn (SpDH), the origin and termination of descending tract cells were examined by the anterograde and retrograde transport methods. Phaseolus vulgaris leucoagglutinin (PHA-L) and Fluorogold (FG) or dextran-tetramethylrhodamine (Rho) were used as neuronal tracers for the anterograde and retrograde transport, respectively. The ventrolateral PB, including Kölliker-Fuse nucleus (KF), sent axons terminating mainly in the ventrolateral parts of rostral trigeminal nuclei of the principalis (Vp), oralis (Vo), and interpolaris (Vi) as well as in the inner lamina II of the medullary (nucleus caudalis, Vc) and SpDH. Although the descending projections were bilateral with an ipsilateral dominance, TSNC received a more dominant ipsilateral projection than SpDH. The cells of origin of the descending tracts were located mainly in KF, but TSNC received fewer projections from the KF than SpDH. Namely, TSNC received a considerable projection from the medial subnucleus of PB and the ventral parts of lateral subnuclei of PB, such as the central lateral subnucleus and lateral crescent area. The other difference noted between TSNC and SpDH was that the former received projections mainly from the caudal two thirds of KF and the latter from the rostral two thirds of KF. These results demonstrate the existence of direct parabrachial projections to TSNC and SpDH that are organized in a distinct manner and suggest that both pathways are involved in the control of nociception.

Animals↗
PubMed1997

Reconstruction of posttraumatic defects of the foot by flow-through anterolateral or anteromedial thigh flaps with preservation of posterior tibial vessels.

Massive posttraumatic defects of the foot in 4 patients and a tibial malunion in another were repaired by flow-through anterior (anterolateral and anteromedial) thigh flaps. Posterior tibial vessels were used as the recipient vessel just below the level of the medial malleolus. Soft-tissue defects in foot-injured patients were covered with flow-through anterior thigh flaps interposing the descending branch of the lateral circumflex femoral system between the transected posterior tibial vessels. In another patient, a combined anteromedial thigh flap and vascularized iliac bone cross-leg "chimeric" flap were successfully transferred for the reconstruction of a malunion of a tibial fracture, which had been accompanied by severe vascular damage to the thigh. The utilization of derivative branches from the lateral circumflex femoral system facilitates revascularization of ischemic areas and simultaneous transplantation of multiple components, as well as preserves recipient vessels. Owing to the stable blood supply, these flaps can be readily processed into both deepithelialized and thin flaps.

Achilles Tendon↗
PubMed1997

Evaluation of skin permeability of drugs by newly prepared polymer membranes.

Four polymeric membranes were prepared consisting of various ratios of 2-hydroxyethyl-methacrylate/polydimethylsiloxane-methacrylate copolymer. These membranes had both lipophilic and hydrophilic domains in their copolymer networks like skin barrier. From permeation studies of the aqueous solutions or suspensions of various lipophilic and hydrophilic drugs using these membranes, a membrane having a similar drug permeability to hairless rat and human skins was selected. Permeation of indomethacin through the selected polymer membrane from simple ointment, gel and a marketed cream were then measured. About 10(2) times higher permeability was found in the polymer membrane than through excised hairless rat skin, but the rank order of the permeability through the polymer membrane among the formulations was the same through the skin membranes. These higher permeations of indomethacin were probably related to physical and chemical properties of pharmaceutical additives in the topical formulations. It is concluded that these synthetic polymer membranes may be utilized as an alternative tool to predict human or rat skin permeability of various (hydrophilic or lipophilic) drugs as well as to screen drug candidates for transdermal drug delivery.

Administration, Cutaneous↗
PubMed1996

Electron microscopic observation of synaptic connections of jaw-muscle spindle and periodontal afferent terminals in the trigeminal motor and supratrigeminal nuclei in the cat.

Previous studies indicate that the trigeminal motor nucleus (Vmo) and supratrigeminal nucleus (Vsup) receive direct projections from muscle spindle (MS) and periodontal ligament (PL) afferents. The aim of the present study is to examine the ultrastructural characteristics of the two kinds of afferent in both nuclei using the intracellular horseradish peroxidase (HRP) injection technique in the cat. Our observations are based on complete or near-complete reconstructions of 288 MS (six fibers) and 69 PL (eight fibers) afferent boutons in Vmo, and of 93 MS (four fibers) and 188 PL (four fibers) afferent boutons in Vsup. All the labeled boutons contained spherical synaptic vesicles and were presynaptic to neuronal elements, and some were postsynaptic to axon terminals containing pleomorphic, synaptic vesicles (P-endings). In Vmo neuropil, MS afferent boutons were distributed widely from soma to distal dendrites, but PL afferent boutons predominated on distal dendrites. Most MS afferent boutons (87%) formed synaptic specialization(s) with one postsynaptic target while some (13%) contacting two or three dendritic profiles; PL afferents had a higher number of boutons (43%) contacting two or more dendritic profiles. A small but significant number of MS afferent boutons (12%) received contacts from P-endings, but PL afferent boutons (36%) received three times as many contacts from P-endings as MS afferents. In Vsup neuropil, most MS (72%) and PL (87%) afferent boutons formed two contacts presynaptic to one dendrite and postsynaptic to one P-ending, and their participation in synaptic triads was much more frequent than in Vmo neuropil. The present study indicates that MS and PL afferent terminals have a distinct characteristic in synaptic arrangements in Vmo and Vsup and provides evidence that the synaptic organization of primary afferents differs between the neuropils containing motoneurons and their interneurons.

Animals↗
PubMed1996

Light microscopic observations of the contacts made between two spindle afferent types and alpha-motoneurons in the cat trigeminal motor nucleus.

Previous studies indicate that cat jaw-muscle spindle afferents can be divided into two types (type I and II) on the basis of their axonal trajectories. The present study examined the relationship between spindle afferent fibers and their target masseter alpha-motoneurons in the cat by using the intracellular horseradish peroxidase (HRP) injection technique, and provided several new findings on the synaptic organization generated between the two. Five type I afferent fiber-motoneuron pairs and nine type II afferent-motoneuron pairs were well stained with HRP. The following conclusions were drawn: 1) A motoneuron received contacts from only one collateral of any given spindle afferent. 2) The number of contacts made between an afferent and a motoneuron ranged from one to three. 3) The contacts made by a spindle afferent were on the same dendrite or dendrites branching from the same primary dendrite. 4) The vast majority of the contacts made by an afferent on a motoneuron were distributed in the dendritic tree within 600 microns from the soma, i.e., in the proximal three fourths of the dendritic tree. The differences observed between the two afferent types were as follows. First, type II afferent terminals made contacts on more distal dendrites of the motoneurons than did type I afferent terminals. Second, the contacts made between a type I afferent and a motoneuron were clustered together, but those made between a type II afferent and a motoneuron were widely dispersed. The present results provided the general rules of synaptic contacts between the spindle afferents and masseter alpha-motoneurons, and demonstrated that the spatial distribution of synaptic contacts on the dendritic tree was different between type I and type II afferents.

Animals↗
PubMed1996

Electroencephalography in schizophrenic patients: comparison between neuroleptic-naive state and after treatment.

Electroencephalography of 12 schizophrenic patients was recorded in a neuroleptic-naive state and after 6.2 +/- 1.1 months of treatment, when they were on medication and in partial remission. Compared with age- and sex-matched controls, the neuroleptic-naive schizophrenics had less alpha 2 power. In the medicated state, alpha 2 power and slow-wave power were reduced as compared with the neuroleptic-naive state. The reduction in alpha 2 power may occur from the early stage of the disease and progress even though the patients are medicated and clinically improved.

Adult↗
PubMed1995

Age-related changes in alpha 1-adrenoceptors in rat prostate.

The age-related changes in the density of alpha 1-adrenoceptors in the dorsolateral lobe of the rat prostate were evaluated in Wistar rats at 8, 52, and 104 weeks of age. [3H]YM617, a newly synthesized alpha 1-adrenergic blocker, was used as the ligand. The mean maximum number of binding sites, or alpha 1-adrenoceptor density (Bmax) +/- SE of 104-week-old rats (11.0 +/- 1.2 fmol/mg protein) was significantly lower than that in the 8-week-old rats (37.0 +/- 4.3 fmol/mg protein) and 52-week-old rats (37.2 +/- 3.4 fmol/mg protein) (respectively, P < 0.01). In contrast, mean affinity (Kd) values +/- SE of these groups showed no significant differences (8-week-old rats, 115.8 +/- 9.1; 52-week-old rats, 100.5 +/- 5.8; and 104-week-old rats, 116.4 +/- 9.8 pM). Mean volumes +/- SE of muscle cells of the prostate were 3.7 +/- 1.1 x 10(3) microns3 at 8 weeks, 30.0 +/- 6.2 x 10(3) microns3 at 52 weeks, and 18.6 +/- 8.2 x 10(3) microns3 at 104 weeks. Volumes for 8-week-old rats were significantly smaller than those for 52-week-old (P < 0.01) and 104-week-old rats (P < 0.05). However, the mean area density of the muscle cells showed no difference among the three groups: 20.1 +/- 2.2% at 8 weeks, 27.3 +/- 2.9% at 52 weeks and 20.3 +/- 3.4% at 104 weeks. In conclusion, the density of YM617-binding sites (alpha 1-adrenoceptors) in 104-week-old rats was lower than in 8- and 52-week-old rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1995

Purification and functional properties of soluble forms of membrane cofactor protein (CD46) of complement: identification of forms increased in cancer patients' sera.

Normal human sera contained 10-60 ng/ml of soluble membrane cofactor protein (MCP, CD46) whereas sera of > 50% of the cancer patients contained > 60 ng/ml. MCP purified by immunoaffinity chromatography from both normal and cancer patients' sera consisted of three bands of 56, 47 and 29 kDa on SDS-PAGE/immunoblotting. The upper two components were increased in cancer patient sera. The 56 and 47 kDa soluble forms served as a cofactor for factor I-mediated cleavage of C3b. MCP expressed on Chinese hamster ovary (CHO) cells protects host cells from human C3 deposition and complement-mediated cytolysis, especially by activation of the alternative pathway. In this same assay system, exogenously added soluble MCP also protected untransfected CHO cells; however, its potency was much less than that of the endogenous membrane form. For example, 8 micrograms/ml of soluble MCP was equal to 10(4) copies/cell of the expressed MCP. Recombinant soluble forms possessed similar activity to the naturally occurring soluble forms and high doses (> 150 micrograms) blocked Arthus-like reaction induced in guinea-pigs by anti-Forssman antibody. These data establish that soluble forms of MCP are present in human sera that possess cofactor activity and their concentrations, especially the 56 and 47 kDa forms, are increased in sera of cancer patients. High doses of the recombinant soluble forms may be therapeutically useful for suppressing inflammatory responses.

Animals↗
PubMed1995

[Histochemical study of biotinylated lectins in prostatic cancer].

We examined the staining pattern of various lectins in the malignant and benign prostatic tissues to clarify the difference of sugar residues of mucosubstances between them. The binding of different lectins (Concanavalia ensiformis [Con A], Triticum vulgaris [WAG], Ricinus communis [RCA-I], Arachis hypogaea [PNA], Ulex europaeus [UEA-I], Glycine max [SBA], and Gliffonia simplicifolia II [GSA-II]) to cells of benign prostatic tissues (17 cases) and adenocarcinoma (54 cases) was evaluated immunohistochemically. SBA which was negative in benign epithelial cells, showed tendency to the binding to prostatic carcinoma (42.6%). UEA-I was significantly bound to the adenocarcinoma (68.5%) compared to the benign prostatic tissue (35.3%). We also examined histochemically 25 pairs of tissues obtained from prostatic adenocarcinoma before and after the various therapies with various lectins. The histological responsiveness on the post-therapeutic specimens showed a significant correlation to the clinical responsiveness to therapy. But the staining pattern of these 7 lectins on the pre-therapeutic specimens did not show a significant correlation to the clinical responsiveness to therapy. In summary, the staining pattern of some lectins in the prostatic cancers is different from that in the benign prostatic tissues.

Adenocarcinoma↗
PubMed1995

[Evaluation of advanced bladder tumor].

Ninety-two cases of advanced bladder tumor treated at the University of Tokyo and branch hospital from January 1977 to December 1992 were analyzed. The advanced bladder tumor was defined as that of higher than pT2 (according to the General Rule for Clinical and Pathological Studies on Bladder Cancer) or that with distant metastases. The following variants were evaluated, the therapeutic methods, the histological type, grade, stage, type of infiltration. The evidence of lymphatic infiltration, vessel infiltration, and lymph node metastases were also reviewed. The survival rate was calculated using Kaplan-Meier's method. In the cases with lymph node metastases, the survival rate was significantly lower than in the cases without metastases (p < 0.01), while no other factors affected the survival rate.

Combined Modality Therapy↗
PubMed1995

[Histochemical expression of proliferating cell nuclear antigen (PCNA) for pre and post chemotherapeutic bladder cancer].

We examined whether the staining of proliferating cell nuclear antigen (PCNA) could be useful as a marker of chemotherapeutic effectiveness in nine patients with invasive bladder cancer treated by bilateral internal iliac artery infusion of cisplatin (CDDP). Two types of monoclonal antibodies PC-10, 19A2 were used for immunohistochemical staining in formalin-fixed, paraffin-embedded tissue sections. There was no difference between positive rates of PC-10 and 19A2. The mean positive rates between pre-chemotherapeutic specimens (15.4 +/- 6.7%) and post-chemotherapeutic specimens (4.2 +/- 3.1%) showed statistically significant difference (p < 001). The immunohistochemical evaluation of PCNA has value for investigation of cell's turnover. Therefore, the changes of PCNA-positive rate could be a historical parameter for the evaluation of chemotherapeutic effects.

Aged↗