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Biomedical subjects

N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 37 records · Page 2Linked to original sources
PubMed1992

Control of trigeminal motoneurons from the cerebellar interpositus nucleus of the guinea pig.

1. Effects of stimulation of the cerebellar interpositus nucleus (IPN) on jaw reflexes and trigeminal motoneurons were studied along with the route responsible for the effects in ketamine-anesthetized guinea pigs. 2. Stimulation in the IPN evoked a bilateral, ipsilaterally dominant, short-latency reciprocal effect on jaw reflexes: a depression of the jaw-closing masseteric reflex and a facilitation of the jaw-opening digastric reflex. This reciprocal phase was followed by a non-reciprocal facilitatory phase. 3. Stimulation in the IPN evoked a short-latency, strychnine-sensitive inhibitory postsynaptic potential (IPSP) followed by a rebound depolarizing potential in the jaw-closing masseter motoneurons (MAMNs) and an excitatory postsynaptic potential (EPSP) in the jaw-opening anterior digastric motoneurons (ADMNs). The time course of the intracellular response of MAMNs to the IPN stimulation was similar to that of the IPN-induced effects on the jaw-closing reflex. In contrast, the duration of the IPN-induced EPSP in ADMNs was shorter than the IPN-induced facilitation of the jaw-opening reflex. 4. After the IPN neurons were lost by injection of kainic acid into the nucleus, the reciprocal effect of the IPN stimulation on the jaw reflexes could not be seen, even though the projection fibers from the trigeminal sensory nucleus to the IPN remained essentially intact. 5. Stimulation in the superior cerebellar peduncle (SP) induced the same reciprocal effect on the jaw reflexes as the IPN stimulation. A lesion of the SP virtually abolished the reciprocal effect on the jaw reflexes of stimulation in the IPN ipsilateral with reference to the SP lesion. 6. Transection of the brain stem at the level immediately caudal to the red nucleus did not affect the reciprocal effect of the IPN stimulation on the jaw reflexes. 7. We conclude that the IPN output bilaterally induces an inhibition of jaw-closing MAMNs and an excitation of jaw-opening ADMNs, oligosynaptically by way of a direct cerebelloreticular projection system via the SP.

Animals↗
PubMed1992

Suppressed serum and urine levels of indoxyl sulfate by oral sorbent in experimental uremic rats.

In uremic patients, the serum concentration of indoxyl sulfate is markedly increased. To determine if oral sorbent (AST-120) suppresses the endogenous synthesis of indoxyl sulfate, it was administered to experimental uremic rats, and the serum concentration and urinary excretion of indoxyl sulfate were quantified by high-performance liquid chromatography. Oral sorbent decreased both the serum concentration and urinary excretion of indoxyl sulfate, suggesting that there was suppression of the endogenous synthesis of indoxyl sulfate by the oral sorbent. Oral sorbent did not decrease the serum concentration and urinary excretion of hippuric acid, but it did alleviate the deterioration of renal function in the experimental uremic rats.

Adsorption↗
PubMed1992

Higher sensitivity of LEC strain rat in radiation-induced acute intestinal death.

LEC strain rats (LEC rats), which have been known to develop hereditarily spontaneous fulminant hepatitis 4-5 months after birth, were highly sensitive to whole-body X-irradiation as compared to WKAH strain rats (WKAH rats). Radiation-induced acute intestinal death occurred at doses higher than 6.5 Gy in LEC rats, and at doses higher than 12.8 Gy in WKAH rats, respectively. By the probit analysis of survival data, it was shown that the LD50/7 value of LEC rats was estimated to be 7.03 Gy which was significantly lower than that (12.99 Gy) of WKAH rats. Histopathological examinations of small intestines from LEC rats 2 days after irradiation at the dose of 8.5 Gy showed severe epithelial death together with edema, whereas little or no significant changes were noted in intestinal epithelium of 8.5 Gy-irradiated WKAH rats. These results suggest that the radiosensitivity of LEC rats to ionizing radiation appears to be higher than that of other strains of rats.

Animals↗
PubMed1992

Skull base metastasis from gastric cancer--case report.

A 48-year-old male presented with a metastatic skull base tumor located on the right of the clivus and the sphenoid sinus, which originated from adenocarcinoma of the stomach. The initial symptom was abducens nerve paralysis and there were no symptoms of upper gastrointestinal tract throughout the course. This gastric cancer, which rarely metastasizes to the central nervous system or osseous system, caused multiple bone metastases which produced the neurological symptoms.

Carcinoma↗
PubMed1992

Studies on condensed-heterocyclic azolium cephalosporins. IV. Synthesis and antibacterial activity of 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)- alkoxyiminoacetamido]-3-(condensed-heterocyclic azolium)methyl cephalosporins including SCE-2787.

The synthesis and in vitro antibacterial activity of 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-alkoxyiminoacetami do] cephalosporins bearing various condensed-heterocyclic azolium groups at the 3 position in the cephalosporin nucleus are described. The thiadiazolyl cephalosporins showed good antibacterial activity against both Gram-positive and Gram-negative bacteria and the MICs of the thiadiazolyl cephalosporins against Pseudomonas aeruginosa was more potent than that of the corresponding 7 beta-[2-(2-aminothiazol-4-yl)-2(Z)-alkoxyiminoacetamido]-3- (condensed-heterocyclic azolium)methyl cephalosporins. Also, the thiadiazolyl cephalosporins bearing (imidazo[1,2-b]-pyridazinium-1-yl)methyl groups at the 3 position showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Among the cephalosporins tested, 7 beta-[2-(5- amino-1,2,4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetamido]-3-(imidaz o[1,2- b]pyridazinium-1-yl)methyl-3- cephem-4-carboxylate (4, SCE-2787) which exhibited the most potent antibacterial activity and the broadest antibacterial spectrum was selected as a parenteral cephalosporin candidate for further biological evaluation.

Cephalosporins↗
PubMed1992

Studies on condensed-heterocyclic azolium cephalosporins. V. Synthesis and antibacterial activity of 3-(condensed-triazolo-pyridinium, -pyrimidinium, and -pyridazinium)-methyl cephalosporins.

As a part of our studies on cephalosporins bearing condensed-heterocyclic azolium methyl groups at the 3 position in the cephalosporin nucleus, we describe here the synthesis and antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)2(Z)-methoxyiminoacetamido] cephalosporins (1-16, 7 beta-[2-(2-amino-5-chlorothiazol-4-yl)-2(Z)- methoxyiminoacetamido] cephalosporins (17,18) and 7 beta-[2-(5-amino- 1,2,4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetamido) cephalosporins (19-23) containing a variety of condensed-heterocyclic triazolium methyl groups at the 3 position in the cephalosporin nucleus. These cephalosporins exhibited potent antibacterial activity, and it appears that condensed-heterocyclic triazolium as well as condensed-heterocyclic imidazolium rings are effective moieties for improving antibacterial activity and the spectrum of activity. Among the cephalosporins tested, 7 beta-[2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3-(5- methyl[1,2,3]triazolo-[1,5-alpha]pyridinium-1-yl)methyl-3-cephem-4- carboxylate (9) and 7 beta-[2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3-(6- methoxy[1,2,4]triazolo[1,5-alpha]pyridinium-1-yl)methyl-3-cephem-4- carboxylate (11) showed good antibacterial activity.

Cephalosporins↗
PubMed1992

Effect of neutralizing monoclonal antibodies on Hantaan virus infection of the macrophage P388D1 cell line.

The effect of neutralizing monoclonal antibodies (N MAbs) on Hantaan virus infection of macrophages was investigated using P388D1 cells, a murine macrophage cell line. MAbs to the G1 protein (G1b) and the G2 protein (G2a and G2c) neutralized viral infectivity in P388D1 cells. N MAbs to G1b showed much higher neutralizing potency than those to G2a and G2c. With each N MAbs, two distinct effects were observed: neutralization of viral infectivity occurring at high concentrations and enhancement of that at low concentrations. Non-neutralizing MAbs, on the other hand, showed only enhancement of viral infectivity even at high concentrations without any inhibitory effects. The Fab fragments of N MAbs showed neither neutralizing nor enhancing activities. However, when the virus-Fab complexes were reacted with the anti-Fab antibodies, both neutralization and enhancement of viral infectivity were restored depending on the dose of Fab fragments. These results indicate that Hantaan virus infection of P388D1 cells is mediated by the Fc portion of the antibodies and neutralization is dependent on the concentration of N antibodies bound bivalently to the neutralization site on the virion.

Animals↗
PubMed1992

[Definition of the chronic fatigue syndrome and its issues].

This article reviewed Definition of CFS proposed by CDC 1988. There are several issues in Definition for CFS of CDC. It is presented that other chronic clinical conditions have been satisfactorily excluded, including preexisting psychiatric diseases in (2) of major criteria. However, fibromyalgia can not be excluded from the fifth symptom of minor criteria, myalgia, and also depression from the ninth symptom. It is practically difficult to define impairment of average daily activity below 50% of the patient's premorbid activity level for a period of at least 6 months, as shown in (1) of major criteria, and it is not adapted for a first visit patient. Definition for CFS of CDC has been discussed on EBV infection, but not written on postviral fatigue syndrome and myalgic encephalomyelitis. Especially whether epidemic type of CFS is present or not was not discussed. Diagnostic criteria of CFS is necessary for clinical practice.

Fatigue Syndrome, Chronic↗
PubMed1992

[Chronic fatigue syndrome--51 cases in the Jikei University School of Medicine].

Between April 1991 and August 1992, we diagnosed 51 cases of CFS who met definition of CFS designated by CDC, 1988. They are 41 female and 11 male, and 78% are women. At first visit, their ages are ranged from 16 to 64 years old, and approximately 45% is 20 to 30 years old. In periods of illness from onset, 39.2% of the patients are in period of 6 month to 1 year, 19.6% within 2 years, and 15.6% within 3 years, respectively. The sufferer who have symptoms of CFS over 10 years long are in 6 cases. Most of patients have already been examined by many other clinics and hospitals. They have been told as no abnormal medical condition, or often as neurosis, depressive state and autonomous imbalance etc. Interesting things are trigger of CFS. 77.5% of patients have onset of flu-like symptom, including 5 cases of acute infectious mononucleosis. In many female patients, symptoms of CFS begun after hand work in addition to psychological factors. Specific laboratory results are not shown in CBC, urinalysis, biochemical studies and inflammatory marhers. 6 cases hare positive Rheumatoid factor and positive ANF are shown in 16 cases (31.3%). Specific patterns of anti EBV antibodies are not shown. Lymphocyte subsets used by monoclonal antibodies are not specific. At the present, prognosis is good and 56.8% of CFS patients are generally improved. For severe cases, NSAID, Sulpiride, Amitryptiline and minor tranquilizer are used.

Adolescent↗
PubMed1992

[A case of allergic bronchopulmonary aspergillosis with no history of bronchial asthma].

A 53-year-old male was admitted to our hospital because of an abnormal shadow in the left upper lung. Bronchofiberscopy revealed edematous mucosa and pus at the orifice of the left upper lobe bronchus. Pathological examination revealed bronchial inflammatory change with infiltration of eosinophils and also the existence of aspergillus in the pus. Mild eosinophilia and elevation of serum IgE level were observed in the peripheral blood, and serum precipitin against Aspergillus fumigatus was positive. Bronchogram showed central bronchiectasis, and the diagnosis of allergic bronchopulmonary aspergillosis (ABPA) was made. In cases of ABPA, bronchial asthma is usually present prior to presentation, but this patient had no history of asthma even though airway hyperresponsiveness to methacholine was confirmed.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1992

[Changes in forehead and sole tissue temperature during cardiopulmonary bypass for acquired cardiac disease].

The forehead tissue temperature (FT-T) and the sole tissue temperature (ST-T) were measured and recorded by a deep body thermometer (Terumo Corp.) during open heart surgery. The changes in FT-T and ST-T after cardiopulmonary bypass (CPB) showed two characteristic patterns; the convergence pattern and the dissociation pattern. It is said that the dissociation pattern can notes a poor peripheral circulation. The deverging point of the two patterns was studied in 65 patients with acquired cardiac disease. We divided the patients into two groups taking 3.5 degrees C of the FT-T and ST-T difference (DT) after 2 hour weaning from CPB. The number of the patients in convergence group (group I) was 42, and that in the dissociation group (group II) was 23. The two groups were compared with the DT and the time required for the rise in each temperature from CPB rewarming to CPB weaning. There was no intergroup difference in the DT when the FT-T began to rise upon CPB rewarming. However, the DT was 3.8 +/- 2.3 (mean +/- SD) degrees C in group I and 7.1 +/- 1.8 degrees C in group II when the ST-T began to rise, and 4.2 +/- 2.5 degrees C in group I and 6.9 +/- 1.4 degrees C in group II when the FT-T reached its peak; the figures were significantly lower in group I (P < 0.01). The time required for the rise in ST-T was significantly shorter in group I (14.8 +/- 17.1 min) than in group II (25.8 +/- 14.7 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗
PubMed1992

Isolation and characterization of cDNA encoding a spicule matrix protein in Hemicentrotus pulcherrimus micromeres.

A cDNA clone, termed pHPSMC, was obtained from the Japanese sea urchin Hemicentrotus pulcherrimus, and it was found to be highly homologous in sequence to the spicule matrix protein cDNA of Strongylocentrotus purpuratus (Sucov et al., Dev. Biol. 120: 507-519, 1987). During early embryogenesis, mRNA complementary to pHPSMC appeared in gastrulae and remained at a similar level until the pluteus stage. In situ hybridization revealed that the mRNA was localized exclusively in primary mesenchyme cells in gastrulae. pHPSMC mRNA was detected in micromeres in vitro after 48 h of culture, but it was not found in blastomeres immediately after isolation. These features suggested that pHPSMC represents the spicule matrix protein cDNA cognate in Hemicentrotus pulcherrimus. In the derived polypeptide, we detected a domain containing a tandemly repeated 13-amino acid sequence as did Sucov et al. (1987). Unexpectedly, the sequence of the repeated element was completely different from that originally reported for Strongylocentrotus purpuratus, but it was very similar to the corrected sequence that appeared recently.

Amino Acid Sequence↗
PubMed1992

Significance of venous drainage for small-bowel allografts.

Small bowel transplantation has proved feasible in rats and in larger animal, but several important questions have yet to be answered before it becomes a potential therapy in man. One consideration is the site of venous outflow of the allograft. Portal drainage, however, re-establishes the physiological route of venous outflow, while systemic drainage creates a partial mesocaval shunt, the metabolic consequences of which have not been studied in detail. Using the canine model in partial mesocaval shunt and porta-caval shunt, we compared the metabolic and histological changes following each shunt. The metabolic changes in Eck were hyperammonemia and amino acid imbalance, while those in partial mesocaval shunt were similar to controls. The histological appearance of the liver in Eck was atrophy, fatty infiltration and deglycogenation, while that in partial mesocaval shunt was completely normal except for minimal fatty degeneration. These data suggest that there is no metabolic or histological disadvantage of systemic venous drainage as compared with control, and because of its technical simplicity, systemic venous drainage may be preferable in small bowel transplantation.

Animals↗
PubMed1992

[Primary malignant lymphoma in the sphenoid sinus with orbital apex syndrome; a case report].

Only 2.0-6.8% of extranodal malignant lymphomas are found in the nasal region and paranasal sinuses. Primary malignant lymphoma of the paranasal sinuses usually occurs in the maxillary or ethmoid sinuses, and is very rare in the sphenoid sinus. Here we report a rare case of primary malignant lymphoma of the sphenoid sinus that was found accompanying orbital apex syndrome. The patient's progressively deteriorating neurological condition was improved after surgery via the transsphenoidal approach. A 52-year-old man was admitted with reduced left visual acuity, diplopia, and retroorbital pain. CT showed an isodense mass in the sphenoid sinus with slight enhancement, and MRI showed that the lesion was slightly hypointense on T1-weighted images, hypointense on T2-weighted images, and slightly enhanced by Gd-DTPA. On January 19, 1989, the patient suddenly became blind. An operation via the transsphenoidal approach was done as an emergency procedure to decompress the sphenoid sinus and the left optic canal. The histological diagnosis was non-Hodgkin's lymphoma of the diffuse large cell type (B cell lymphoma). Malignant lymphoma in the paranasal sinuses is usually biopsied and treated by chemotherapy and/or radiotherapy without surgical resection. In this rare case, an operation via the transsphenoidal approach was effective in improving the patient's visual acuity.

Humans↗
PubMed1992

A large aneurysm of the persistent primitive hypoglossal artery.

An aneurysm of a persistent primitive hypoglossal artery (PHA) particularly at its junction with the basilar artery, often poses therapeutic problems. This is attributable not only to the size and location of the aneurysm but also to the fact that the persistent PHA is functionally the single artery providing blood in posterior circulation. We report a 31-year-old man with a large aneurysm of the persistent PHA at its junction with the basilar artery and review the existing literature. We clipped the broad neck of the aneurysm through a lateral suboccipital craniectomy; however, the patient suffered a second episode of subarachnoid hemorrhage. Angiography disclosed a slipped clip incompletely obstructing the persistent PHA. He received no further treatment for the aneurysm because of his deteriorating condition. Direct surgical treatment, although it failed to obliterate the aneurysm neck in our patient, should be recommended for a persistent PHA aneurysm.

Adult↗
PubMed1991

Down-regulation of prostaglandin E2 receptors in regenerating rat liver and its physiological significance.

The properties of prostaglandin (PG) E2 receptors in regenerating liver were studied using rat hepatocytes in primary culture. The control cells possessed stereo-specific PGE2 receptors with Bmax and Kd values, at 4 degrees C, of 526 fmol/mg protein and 6.5 nM respectively. In cells from regenerating liver after 70% hepatectomy, Bmax was reduced to 42-43% that of the controls; Kd did not change. Administration of indomethacin before surgery prevented Bmax reduction. These results indicate that PGE2, produced during the regeneration process, evoked cellular events and regulated the density of its receptors.

Animals↗