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Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 307 records · Page 17Linked to original sources
PubMed1996

Surgical treatment of Borrmann type IV gastric carcinoma: relevance of lymphadenectomy in improving survival.

BACKGROUND: Borrmann type IV gastric carcinoma carries a poor prognosis, even if curatively resected. The benefit of a lymphadenectomy is unknown. STUDY DESIGN: A retrospective study was designed to evaluate whether improvements have been made in the treatment of type IV gastric carcinoma over the past decade. The 345 patients with type IV carcinoma who underwent laparotomy within a recent 16-year period were split into two groups: one group of patients who underwent laparotomy between 1977 and 1985, and the other between 1986 and 1992. Survival data were compared between these two groups and prognostic factors for type IV gastric carcinoma were assessed by multivariate analysis. RESULTS: A significant difference in survival was observed between the groups, both of which underwent curative resection, despite a lack of difference in background factors. The improvement was more prominent among patients with nodal metastases and insignificant among patients without nodal metastases. Multivariate analysis identified nodal metastasis as a major independent prognostic factor. CONCLUSIONS: An improvement in outcome was presumably achieved through extended lymphadenectomy. However, the survival rate remains unsatisfactory, and further advances in the treatment of this disease are needed.

Adenocarcinoma↗
PubMed1996

[Usefulness of MRA in an infant with cerebral infarction due to streptococcal meningitis].

We described a 4-month-old boy with cerebral infarction due to streptococcal meningitis. He complained of cough and high fever for 2 days. On the next day he admitted to our hospital because of bad humor, drowsiness, and vomiting associated with high fever, respiratory failure and loss of consciousness. On admission, he had opisthotonic posturing, anisocoria and elevated deep tendon reflexes with left side dominance. The cerebrospinal fluid showed increased cells (564/mm3), protein (295 mg/dl), and decreased sugar (1 mg/dl). Streptococcus pneumoniae was detected in the cerebrospinal fluid. Despite intensive treatment by antibiotics, glycerol, and dexamethasone, general condition was worsened, MRI showed a high intense area along the territory of bilateral anterior cerebral arteries and left middle cerebral artery 3-D time-of-flight MRA revealed a decreased signal of these arteries, confirming cerebral infarction. Recanalization of the arteries were observed 17 days after the first MRA examination. Since complication of cerebral infarction influences the prognosis of meningitis, repetitive MRA is very beneficial in patients with bacterial meningitis in order to evaluate the vascular lesion.

Cerebral Infarction↗
PubMed1996

[Cord blood stem cell transplantation for a patient with acute myelogenous leukemia (M1)].

A five-year-old boy with acute myelogenous leukemia in relapse was treated by HLA-matched cord blood stem cell transplantation. The patient was preconditioned with 16 mg/kg of busulfan, 15 mg/kg of thiotepa and 90 mg/kg of cyclophosphamide and 2.45 x 10(7)/kg of cord blood mononuclear cells were infused to the patient on October 19th 1995 without the prophylaxis of graft-versus-host disease (GVHD). From the fifth day following the transplant, rG-CSF was administered at a dose of 300 micrograms/m2/day. Hematopoietic recovery was obtained as following; WBC over 1000/microliters was on +18 day, neutrophil over 500/microliters was on +20 day, reticulocyte over 20/1000 was on +28 day and platelet over 50 x 10(2) microliters was on +91 day. Engraftment was confirmed by DNA restriction fragment length polymorphism (VNTR) on +28 day. In spite of absence of prophylaxis of GVHD, the patient did not develop any signs of GVHD, and leukemia relapsed on +105 day. The patient died of leukemia relapse on +251 day. This is the first case of cord blood stem cell transplantation in Japan.

CD4-CD8 Ratio↗
PubMed1995

Neural activity of chorda tympani mechanosensitive fibers during licking behavior in rats.

The chorda tympani nerve, supplying the anterior two-thirds of the tongue, contains gustatory and mechanosensitive afferent fibers. We have analyzed discharge patterns in rats of various fibers recorded from dissected nerve filaments during licking behavior of which 4 were taste-sensitive and 12 mechanosensitive. The incidence of these two types were estimated electrophysiologically under anesthesia and their conduction velocity measured. Recordings in freely moving animals showed that the mechanosensitive fibers innervating the dorsal part of the tongue gave two burst discharges per lick, suggesting that contact of the tongue with the upper incisors and/or lip occurred during tongue protrusion and retraction. The fibers from the tip of the tongue showed one burst discharge per lick, which was the response to contact with a drinking spout. No rhythmical discharges synchronized with lick signals were observed in the fibers from the lateral part of the tongue or the taste-sensitive fibers. Such mechanoreceptor discharges were difficult to detect in recordings from the whole chorda tympani nerve. This masking of responses was due mainly to activation of a small number of mechanosensitive fibers by licking-induced mechanical stimulation. The lubricating action of saliva also decreased mechanoreceptor sensitivity. Despite their small number, the mechanosensitive fibers had axons with faster conduction velocities (larger diameter) than the taste-sensitive fibers. This was probably the reason why dissected nerve bundles more frequently showed mechanical than taste responses in conscious rats.

Action Potentials↗
PubMed1995

Involvement of HPC-1/syntaxin-1A antigen in transmitter release from PC12h cells.

We examined the effect of antiserum against HPC-1/Syntaxin-1A on the norepinephrine release from digitonin-permeabilized PC12h cells. PC12h cells were permeabilized with digitonin and preincubated with nonimmunized serum or antiserum against HPC-1. The release of norepinephrine was measured in the presence or absence of calcium. The calcium-dependent norepinephrine release was increased in the cells preincubated with anti HPC-1 antiserum. However, with a higher concentration of anti HPC-1 antiserum, the calcium-dependent norepinephrine release was decreased, possibly because of a nonspecific effect. In the case of purified IgG, the same results were obtained. These findings suggested that HPC-1 plays an important role in the exocytosis of transmitter presumably by suppressing the membrane fusion process between the synaptic vesicle and presynaptic membrane.

Analysis of Variance↗
PubMed1995

Four hydrophobic segments in the NH2-terminal third (H1-H4) of Na,K-ATPase alpha subunit alternately initiate and halt membrane translocation of the newly synthesized polypeptide.

Transmembrane disposition of the NH2-terminal third of the Na,K-ATPase alpha subunit was studied using an experimental approach that involved in vitro endoplasmic reticulum membrane insertion of chimeras. These chimeras consisted of four truncated amino-terminal segments of the alpha subunit linked at amino acid residues 126, 179, 313, and 439 to chloramphenicol acetyltransferase (CAT), a reporter protein, that contains a consensus sequence for N-linked glycosylation. The fusion sites were located after one of the four hydrophobic segments (H1-H4). The results showed that the chimeras in which the alpha subunit was truncated at positions 126 and 313 were glycosylated, and the glycosylated peptides were protected by membranes from proteolysis. However, the other two chimeras were not glycosylated and the inserted peptides were digested by protease into fragments which did not immunoprecipitate with anti-CAT. These results clearly demonstrate that hydrophobic segments H1 and H3 function as signal/anchor type II, and H2 and H4 function as halt transfer signals. Furthermore, membrane insertion of the NH2-terminal third of Na,K-ATPase alpha subunit is achieved by a series of alternate signal/anchor type II and halt transfer sequences.

Amino Acid Sequence↗
PubMed1995

A Comparison of Mass Screening for Breast Cancer Using Mammography and Physical Examination Alone in Japan.

To compare the sensivity of breast cancer screening methods by conventional physical examination and film mammography, a trial of mass screening for breast cancer using mammography was principally carried out in asymptomatic women over 50 years of age in Tokushima Prefecture. In this trial craniocaudal and mediolateral oblique imagings of the breast using two-view film mammography and physical examination, using inspection and palpation of the breasts were performed independently. Breast cancer was detected in 8 of a total of 950 examinees by mammography alone, and no cases of breast cancer were detected by physical examination. The detection rate of breast cancer was 0.84%, that is 7 times higher than that(0.12%) obtained by conventional mass screening using physical examination alone. The detection rate of increased especially in the sixth and seventh decades of life. The stage of the detected breast cancer was stage 0 (Tis) in 5 cases and stage T, with a tumor size of 1.0 cm or less, in 3 cases. All 8 cases were in the early stage, and they underwent breast conservation therapy. Based on these results, it is recommended to employ mammography in breast cancer screening for asymptomatic women aged over 50 years. We consider mammography alone may be sufficient for mass screening for breast cancer in these subjects.

Journal Article↗
PubMed1995

A Malignant Phyllodes Tumor of the Breast in a 6-Year Old Girl.

We recently encountered a 6-year-old girl with a malignant phyllodes tumor of the breast. The patient's mother noticed a tumor on the right breast of her first doughter at 8 months after from her birth. The baby was brought to the Second Depertment of Surgery, University of Tokushima, at age 20 months. We recommended removal of the 3.5 x 2.9 cm tumor in the right breast, but it was not done. Next, she visited our department at 6 years of age because the tumor had gradually enlarged, reaching a size of 4.3 &timus; 4.0 cm. She underwent excisional resection of the tumor, and the tumor was diagnosed as a malignant phyllodes tumor of the breast coexisting with a borderline phyllodes tumor. To our knowledge, this is the youngest reported case of a malignant phyllodes tumor of the breast. Moreover, the malignant lesion was positive for estrogen receptor (ER) and showed strong proliferating cell nuclear antigen (PCNA) staining. On the other hand, the borderline part was negative for ER and showed weak PCNA staining. Thus, in the present case, the expression of ER, the exposure to estrogen (for example, the mother's estrogen during gestation) and increase in the proliferation rate may have played important roles in the mechanism of the transformation of the phyllodes tumor.

Journal Article↗
PubMed1995

Autocatalytic inactivation of lysosomal cathepsins is associated with inhibition of protein breakdown by insulin-like growth factor-1 (IGF-1) in myotubes.

Protein breakdown was monitored in C2C12 myotubes as the rate of release of radioactivity after prelabeling cell protein with [3H] tyrosine. IGF-1 (13 nM) and insulin (100 nM) prolonged the half-life of long-lived proteins. Enzymatic activities of cathepsins B and B+L were inhibited by the addition of IGF-1 or insulin. Immunoblotting of cathepsins B and L revealed extensive degradation of heavy chain forms by IGF-1. However, neither expression of cathepsins B and L genes nor expression of cystatin beta, an intrinsic inhibitor for cathepsins, was influenced. The addition of E-64, L-3-carboxy-trans-2,3-epoxypropionyl-leucylamide-(4-guanidin o) butane, a inhibitor of cathepsins B and L, increased protein contents of heavy chains of cathepsins B and L in the IGF-1 treated cells. Inhibition of protein breakdown by IGF-1 is mediated by autocatalytic inactivation of lysosomal cathepsins B and L.

Analysis of Variance↗
PubMed1995

The pathogenic role of the NMDA receptor in hyperthermia-induced seizures in developing rats.

Hyperthermia-induced seizures (HS) in rats have been used as a model of febrile seizures. Activation of the N-methyl-D-aspartate (NMDA) receptor by increased extracellular glutamate (Glu) in the cortex during hyperthermia may be involved in the induction of HS and HS kindling. To confirm this hypothesis, the effects of a potent blocker of the NMDA receptor, MK-801, on the threshold and pattern of HS were evaluated. The threshold temperatures for rats given 0.1 (low dose) and 0.5 (high dose) mg/kg MK-801 (i.p.) for the first time were 41.6 degrees C (39.7-42) (median, range) and 42.0 (41.2-42.0), respectively, which were significantly higher than the 40.5 (39.4-41.2) for rats without MK-801 administration (P < 0.01). The recurrent occurrence of HS suppressed the increase in the threshold temperature with age, and changed the seizure from partial to generalized seizures (HS kindling), whereas these effects of recurrent HS on the threshold and pattern of HS were inhibited by the high dose (0.5 mg/kg) of MK-801. MK-801 blocks HS and HS kindling. The activation of the NMDA receptor during hyperthermia plays an important role in the induction of HS and HS kindling.

Age Factors↗
PubMed1995

Inhibitory effect of sympathetic stimulation on activities of masseter muscle spindles and the jaw jerk reflex in rats.

1. To evaluate sympathetic effects on jaw muscles, the discharges of masseter muscle spindle afferents, jaw muscle electromyographic (EMG) activities and blood flow changes were compared in anaesthetized decerebrate rats before and during electrical stimulation of the cervical sympathetic trunk. 2. To eliminate the possibility of efferent control from the trigeminal motoneurones, muscle spindle activity was recorded from the cut peripheral end of the masseter nerve. The absence of a sympathetic component in the masseter nerve was confirmed by the horseradish peroxidase method. 3. Electrical stimulation of the sympathetic nerve at frequencies within the physiological range reduced muscle spindle afferent discharges evoked by passive jaw opening. 4. Sympathetic stimulation also reduced the EMG activity evoked by the jaw jerk reflex, which may reflect a sympathetic effect on spindle afferents. After cessation of stimulation, a transient increase in EMG activity was observed, which may be due to efferent supply from the trigeminal motoneurones. During rhythmical jaw movements, no sympathetic effect on EMG activity was detected. 5. The above sympathetic effect on muscle spindle afferents and EMG activity was independent of blood flow changes.

Action Potentials↗
PubMed1995

Muscle undergoes atrophy in association with increase of lysosomal cathepsin activity in interleukin-6 transgenic mouse.

Interleukin(IL)-6 transgenic mice were produced by microinjection of human IL-6 cDNA fused with H-2Ld promoter into the pronucleus of fertilized eggs from C57BL/6J mice. At 16 weeks old, the gastrocnemius muscles of the IL-6 transgenic mice became atrophic as compared to those of the normal mice, while the body weights increased significantly. The activities and mRNA levels of lysosomal cathepsins B and L were increased in the muscles of the transgenic mice. Immunohistochemical study on the muscles showed increased staining of both cathepsins B and L in the transgenic mice. IL-6 is responsible for enhanced muscle catabolism by activating the lysosomal cathepsin (B and L) system.

Animals↗
PubMed1995

Safety of the donor in living-related liver transplantation--an analysis of 100 parental donors.

The safety and lack of undue operative stress on the donor are documented from an analysis of 100 parental donors, whose children (3 months to 17 years old), received LRLTx at our institution between June 1992 and May 1994. Survival rate of recipients was 86%. No primary nonfunctioning liver was observed. The donors were 56 mothers and 44 fathers. Their ages ranged from 19 to 51 years and their weight ranged from 44 to 80 kg. They received partial liver resections to harvest the grafts. With regard to the liver graft, the left lobe was used in 24 cases (group L) and the left lateral segment was used in 75 cases (group S). The right lobe was used in one case. In the two groups, blood losses were 242 +/- 5 (S) and 312 +/- 14 ml (L); operation times were 6.22 +/- 0.11 (S) and 7.15 +/- 0.21 hr (L), respectively; in both groups, the postoperative hospital stay was 11 days (S, L). No significant differences between the two groups were observed in peripheral RBC and WBC count or serum AST. An increase in total bilirubin was not observed. In the exceptional case using the right lobe, blood loss of 2300 ml necessitated a blood transfusion of 1000 ml, and the total bilirubin increased up to 4.0 mg/dl on the third postoperative day, which prolonged the postoperative hospital stay to 17 days. These results conclusively suggest that safety is guaranteed when the left lobe or the left lateral segment is used as the liver graft for LRLTx.

Adolescent↗
PubMed1995

Incidence, diagnosis and significance of multiple gastric cancer.

Of 2790 patients with gastric cancer undergoing surgery between January 1978 and December 1993, 160 (with 356 neoplastic lesions) had synchronous multiple cancer. Of these lesions 271 (76 percent) were early cancers. Only 85 (53 percent) of the 160 patients were diagnosed before operation as having multiple cancer; 69 further patients (43 percent) were diagnosed during the course of the operation. Small flat (IIb) and depressed (IIc) type lesions had a propensity to be missed before operation. The incidence of multiple cancer was relatively low, indicating that several microscopic lesions might have been overlooked in this series. There has, however, only been one patient (1 percent) with subsequent cancer of the gastric remnant of 126 with multiple cancer and postoperative gastric remnants over the past 16 years. This might be because of co-resection of unrecognized lesions by distal gastrectomy in 68 percent of the patients. Alternatively some microscopic cancers might not invariably be destined to grow into clinically significant lesions over 10 or more years.

Female↗
PubMed1995

Surgical approach for maintaining nonischemic conditions of the liver in acute hepatic vein obstruction.

To establish a possible surgical approach for preventing warm ischemic injury to the liver followed by hepatic vein occlusion (HVO), the hepatic hemodynamics and energy metabolism were investigated in an acute canine HVO model with and without hepatic arterial blood flow. Arterial blood ketone body ratio (AKBR; acetoacetate/3-hydroxybutyrate) and adenylate energy charge potential (ECP = [ATP + 1/2 ADP]/[ATP+ADP+AMP]) of the liver tissue were measured during and after 60 min of HVO. In the group with hepatic arterial blood flow, in which arterial blood was drained by hepatofugal portal flow via the venovenous bypass, total hepatic blood flow, portal vein pressure, ECP, and AKBR were maintained at almost normal level after the termination of HVO, resulting in the survival of all animals for 3 days or longer. By contrast, in the group without hepatic arterial blood flow (warm ischemic group), total hepatic blood flow was maintained at less than 60% of preischemic value, and portal vein pressure gradually increased up to twice the preischemic value. ECP decreased from 0.81 +/- 0.06 to 0.71 +/- 0.07 along with increasing portal venous pressure, and AKBR also decreased from 1.23 +/- 0.12 to 0.63 +/- 0.23, resulting in no survival longer 6 hr. It was concluded that hepatic arterial blood flow during HVO, if drained as hepatofugal portal flow, could maintain nonischemic conditions in the liver, despite vena cava obstruction, by providing an alternate outflow via reversed flow in the portal vein.

Animals↗
PubMed1995

Changes in lymphocyte beta 2-adrenoceptors after hepatic resection.

Hepatic resection promotes such a high degree of surgical stress that it induces deterioration of various vital functions, which may involve the breakdown of signal transduction systems. To investigate the influence of surgical stress on signal transduction, we studied ligand-receptor specific binding activity after hepatic resection, focusing on lymphocyte beta 2-adrenoceptors. The maximum binding capacity (Bmax) and the dissociation constant (KD) were determined by radioligand binding assay using (-)3H-CGP12177 as a ligand. In the hepatectomy group, Bmax significantly decreased from 1380 +/- 109 to 799 +/- 49 receptors/cell on postoperative day (POD) 3 and to 802 +/- 93 receptors/cell on POD 7 (P < 0.05). In the control group, however, it did not significantly change after the operation. No significant changes in KD were found in either of these groups. The Bmax alteration was not due to the redistribution of lymphocyte subsets or receptor down regulation, but to the decrease in the Bmax of the individual subset. The hepatectomy group was divided into two groups according to the postoperative arterial ketone body ratio (AKBR): Group A, AKBR maintained at 0.7 or more; and Group B, AKBR decreased to below 0.7. The Bmax decrease, a percentage of the preoperative value, of Group B was significantly smaller than that of Group A (48.4 +/- 3.9 and 72.3 +/- 7.3%, respectively, P < 0.05). These results suggest that intense surgical stress, produced by hepatic resection, may influence even ligand-receptor binding parameters, and the decrease in AKBR can indicate the magnitude of surgical stress.

Adrenergic beta-Antagonists↗