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Biomedical subjects

S Endo

Publications and source records attributed to S Endo.

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

Determination of the relative neutron sensitivity of a C-CO2 ionization chamber.

The neutron sensitivity of a C-CO2 ionization chamber has been experimentally determined in the neutron energy range of 0.1-1.2 MeV. Eleven kU data were obtained which ranged from 0.04 to 0.1 as a function of neutron energy. There were two peaks in the spectrum of the kU factor, and their positions corresponded to the resonance energies of the kerma factors of carbon dioxide, of which the energies are about 0.4 and 1 MeV. The present data agree with the data obtained at the National Institute for Radiological Sciences in Chiba, Japan (NIRS). The energy dependences of the sensitivity were calculated by using the kerma and the W-value ratios of gas to soft tissue for comparison. The experimental data were reproduced well by the calculations.

Biophysical Phenomena↗
PubMed1996

Cellular signals regulating antibiotic sensitivities of bacteria.

The effects of bacterial masses upon the drug resistance of neighboring bacteria were investigated. The experiments were performed with plastic Petri dishes divided into two identical compartments. A growing mass of Bacillus subtilis (signal emitter cell) in one compartment exerted enhancing effects upon the erythromycin and streptomycin resistance of Bacillus carboniphilus (signal recipient) cells, sparsely seeded in the other compartment, through the plastic wall and the air. These effects of the growing mass of cells are attributed to the emission of "sonic" signals.

Anti-Bacterial Agents↗
PubMed1996

Structure determination of an immunopotentiator peptide, cinnamycin, complexed with lysophosphatidylethanolamine by 1H-NMR1.

The three-dimensional structure of a complex of cinnamycin, a 19-amino acid residue immunopotentiator peptide, and lysophosphatidylethanolamine was determined by 1H-NMR. The complex was cylindrical in shape, 11 A in diameter and 26 A in length, excluding the acyl chain of the phospholipid. The peptide had a hydrophobic pocket surrounded by residues Phe-7 through Ala(S)-14 to bind to the head group of the ligand. Fitting of the head group to the hydrophobic pocket was so good that other than a glycerophosphoethanolamine head group would be unable to fit the pocket. The goodness of the fitting is compatible with the strict specificity of ligand binding of the peptide.

Amino Acid Sequence↗
PubMed1996

Primary malignant lymphoma of the brain: demonstration of frequent p16 and p15 gene deletions.

The p16 (MTS-1) gene, a candidate tumor suppressor gene, was examined by means of Southern blot, PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) and nucleotide analyses in 5 cases of primary malignant lymphoma of the brain. By Southern blot analysis, the p16 gene was found to be deleted in at least 4 cases, homozygously (3 cases) or hemizygously (1 case). The p15 (MTS-2) gene, another candidate tumor suppressor gene located in the vicinity of the p16 gene, to which it shows structural and functional similarity, was also found to be deleted in 4 cases. Our frequent detection (80%) of p16 and p15 gene deletions might suggest that these deletions are closely related to carcinogenesis in primary malignant lymphoma of the brain. SSCP and nucleotide analyses revealed no mutations of the p16 gene in any of the cases.

Adult↗
PubMed1996

A comparative study of glioma cell lines for p16, p15, p53 and p21 gene alterations.

A total of 10 glioma cell lines were examined for alterations of the p16, p15, p53 and p21 genes, which are tumor suppressor genes or candidates with direct or indirect CDK-inhibitory functions. Genetic alterations (deletions or mutations) were frequently seen in the p16, p15 and p53 genes in these cell lines, but not in the p21 gene. When the states of the p16, p15 and p53 genes were compared among cell lines, all the cell lines showed abnormalities in at least 1 gene, often in 2 or 3 genes coincidentally, suggesting that dysfunction of these genes is closely related to glioma cell growth. Although alteration of all 3 genes was most frequent, there were cell lines having either p16/p15 or p53 or pl6 and p53 gene alterations, suggesting that the time order of these genetic alterations was variable depending on the cell line. Among cell lines examined, one with homozygous p53 gene deletion seemed of particular practical value, since such a cell line might be useful in various studies, including investigation of the functions of various mutant p53 genes in the absence of heteromeric protein formation. On examination of the primary tumor tissues, the same alterations of the p16/p15 and p53 genes as detected in the cell lines were demonstrated in all 6 cases examined: p16/p15 gene deletion in 1, p16 gene mutation in 1 and p53 gene mutations in 5 cases. This suggested that the p16/p15 and the p53 gene alterations and their combinations in at least some glioma cell lines reflected those in the primary glioma tissues.

Adult↗
PubMed1996

Computerized electroencephalogram in untreated schizophrenics: a comparison between disorganized and paranoid types.

Computerized electroencephalogram (CEEG) data were obtained from 30 patients with the disorganized type and 20 patients with the paranoid type of acute untreated schizophrenia and compared with data from age- and sex-matched controls. All patients with acute untreated schizophrenia exhibited more pronounced delta, theta, alpha 1 and beta 1 activity and less prominent alpha 2 activity than the control subjects. These findings support previous studies, and indicate the coexistence of cerebral hypofunction and excitability in acute schizophrenic patients. Compared with the controls, patients with disorganized type schizophrenia had significant increases in theta and beta 1 and decreases in alpha 2 activities; but a significant increase in delta and alpha 1 activities in the posterior regions and beta 2 activity in the frontal regions of the brain. Patients with paranoid type schizophrenia showed significantly increased delta activity in the posterior regions, increased alpha 1 activity in the anterior regions and decreased alpha 2 activity in both these regions. In the paranoid type, however, there was no significant finding for the theta, beta 1 and beta 2 activities. Disorganized type schizophrenics exhibited more increased theta and decreased alpha 2 activity than patients with paranoid type schizophrenia. The CEEG differences between the disorganized and the paranoid types appear to reflect different clinical entities and may help to differentiate both schizophrenias.

Adult↗
PubMed1996

Dosimetry of mixed neutron and gamma radiation with paired Fricke solutions in light and heavy water.

Paired Fricke solutions, made up from light water or heavy water and 0.8N in H2SO4 and 1 mM in Fe(NH4)2(SO4)2 and NaCl, were calibrated with 60Co gamma rays and with mixed neutron and gamma radiation from a 252Cf source. Absorbance increases, AL and AH, in light- and heavy-water Fricke dosimeters, respectively, increased with fast-neutron and gamma-ray tissue doses, Dn (GY) and D gamma (GY), of the mixed radiation as follows: AL = 0.00178Dn + 0.00371D gamma; AH = 0.00121Dn + 0.00442 D gamma. G-values of 7.2 and 5.5 were obtained for 252Cf neutrons in light- and heavy-water Fricke dosimeters, respectively. When we applied the pair of equations to AL and AH values observed after exposure to mixed radiation in a nuclear reactor, resulting Dn and D gamma values agreed within 10% to doses measured with paired ionization chambers. Doses required for Fricke dosimeters were 5 Gy or more. In contrast, we found that micronuclear yields in onion roots can measure the neutron component of mixed radiation fields at the order of 10 cGy with reasonable accuracy even if the neutron to gamma-ray dose ratio is unknown.

Californium↗
PubMed1996

Extradural optic nerve decompression for fibrous dysplasia with a favorable visual outcome.

A 10-year-old boy with progressive left visual disturbance associated with craniobasal fibrous dysplasia underwent left frontotemporal craniotomy. Dysplastic lesions of the sphenoid ridge, orbital roof, anterior clinoid, and ethmoid sinus were removed through an extradural pterional approach and the optic nerve was completely decompressed. His vision was markedly improved postoperatively. Consecutive follow-up studies for 3 years have shown no deterioration of his visual acuity. Early optic nerve decompression is highly recommended to preserve visual function in patients with craniofacial fibrous dysplasia causing visual disturbance.

Child↗
PubMed1996

Elevated plasma basic fibroblast growth factor in brain tumor patients.

We attempted to determine whether the plasma concentration of basic fibroblast growth factor (bFGF) was elevated in brain tumor patients. The plasma concentration of bFGF was measured in 55 brain tumor patients and 17 normal subjects by enzyme immunoassay. Upper limit of plasma bFGF in the normal subjects was 1.6 pg/ml. Elevated plasma bFGF levels were observed in 28 patients including 13 of 17 glioma patients, eight of 19 benign tumor patients, and seven of 19 malignant tumor patients. Twelve of 14 malignant glioma patients had elevated plasma bFGF levels. There was a good correlation (r = 0.42, p < 0.05) between the elevated plasma bFGF level and the tumor volume. Further studies are needed to determine whether the plasma bFGF level is a clinically useful diagnostic and prognostic marker for patients with brain tumors.

Adult↗
PubMed1996

Immunohistochemical characterization of monoclonal antibodies (PDs) as markers of the periderm in the developing chicken embryo.

The outermost surface cell layer of the developing embryo, the periderm, arises from the initial single layer of ectoderm and is eventually exfoliated from the stratified epidermis, which has the same ectodermal origin. In this study, monoclonal antibodies against chicken limb bud ectoderm were generated and screened for those which stained the periderm. Four separate antibodies termed PD2, 3, 7 and 9 were obtained from 180 mixed hybridomas. These PD antibodies stained the periderm selectively at all stages examined (stage 20-42). By correlating the results of immunohistochemistry with observations made by transmission electron microscopy, it was revealed that PD antibodies stained both the squamous periderm at an early stage and rounded bulging peridermal cells just before exfoliation. Therefore we feel that PD antibodies may be useful in further systematic investigations of the development and function of the chicken embryonic periderm.

Animals↗
PubMed1996

Prevention of cerebrovasospasm following subarachnoid hemorrhage in rabbits by the platelet-activating factor antagonist, E5880.

Recently, an important role of platelet-activating factor (PAF), an inflammation mediator, has been demonstrated in the genesis of cerebral vasospasm following subarachnoid hemorrhage (SAH). In the current study, the authors examined whether intravenous administration of the novel PAF antagonist, E5880, can prevent vasospasm following SAH in rabbits. A vasospasm model was produced in three groups of rabbits using two subarachnoid injections of autologous arterial blood, followed by intravenous administration of distilled water (control), a low dose of E5880 (0.1 mg/kg in distilled water), or a high dose of E5880 (0.5 mg/kg in distilled water). Neurological deterioration was largely prevented in the rabbits that received E5880. Basilar artery constriction was also reduced by both doses of E5880. Histological examination at autopsy predominantly showed ischemic changes in the brain. Animals in each E5880-treated group exhibited ischemic changes less frequently than those in the control group. Plasma thromboxane B2 concentrations were reduced in rabbits treated with E5880. Platelet-activating factor was immunolocalized in the intima and media of the basilar artery in the control group. The PAF immunoreactivity demonstrated in the basilar artery was decreased in the E5880 groups in a dose-dependent manner. Thus, this study provides evidence that PAF may play a role in the pathogenesis of vasospasm after SAH and that intravenous administration of E5880 is a promising approach in preventing vasospasm.

Animals↗
PubMed1996

[The origin and development of the herbal gardens of the Owari clan].

The early herbal garden of the Owari Clan was called Ofuke-Oyakuen. By careful reading of the "Illustration of the Honorable Herb Garden (OYakuen no Zu), it is pointed out that this garden might have been opened around 1562 when 39 species of herbs granted by Shogun Iemitsu were planted. This garden was enlarged in about 1684. We found that the well-known "Honorable Illustration of Former Herb Garden (Moto-oyakuen On-ezu)" was a drawing of a part of this enlarged herbal garden. On the other hand, in 1735 a new herbal garden, Oshitayashiki-oyakuen was opened for cultivation of Panax Shinseng. While this garden produced fair results at Panax cultivation, it was closed in 1869 at the Meiji Restoration. In the last days of the Tokugawa regime, herbalists of this garden had made original advances in natural history.

History, 17th Century↗
PubMed1996

[Chest wall reconstruction, relation between reconstruction method and infection].

We have operated 52 cases of chest wall resection in these 20 years. Twenty five cases in it were reconstructed by unabsorbable artificial materials such as Marlex mesh, Gore-Tex sheet and some others (Group 1). Eleven cases were covered with the net knitted by absorbable threads or muscle flaps (Group 2). Resting 16 cases have not received any definitive renovations (Group 3). Group 1 has suffered from such severe postoperative complications as acute empyema (8%) and chronic empyema (8%). Few cases in Group 2 has had infectious complication and ventilatory disturbance. Rate of postoperative vital capacity in Group 3 was the lowest value among three groups, though they had the smallest chest wall defects. We obtained following conclusions from this study. Every chest wall defect should be repaired by some way even if the defect were small. Chest wall defect in compromised host should be repaired by absorbable artificial material and muscle flap. Unabsorbable artificial materials are now indispensable for the reconstruction of large chest wall defect, however we must fully take care of postoperative infections in cases of its use.

Biocompatible Materials↗
PubMed1996

[A case of occult AVM diagnosed 17 years after subdural hematoma in the neonatal period].

There have been few reports on cerebral arteriovenous malformation (AVM) of newborns. We present here an interesting case of occult AVM diagnosed 17 years after an episode of acute subdural hematoma in the neonatal period. The cause of subdural hematoma had remained unclear and the patient had suffered from an intractable epilepsy of 17 years duration. Seizures were mainly characterized by drop attacks and included other seizure types such as complex partial seizure and generalized tonic clonic seizure. The symptoms had gradually become worse and the intervals between the occurrences of symptoms had become shorter. An interictal scalp EEG showed a focal spike in the left temporoparietal lobe. CT and MRI of that region demonstrated a porencephalic cyst which was supposed to have resulted from an old hematoma. There were no vascular abnormalities in angiography. Temporoparietal craniotomy and a corticogram were performed. The cortex with a focus was resected and the disappearance of a focal spike in the corticogram was confirmed during operation. Microscopically the cortex included AVM with gliosis. The initial postoperative course was good and seizures disappeared immediately after the operation. However, the symptoms of drop attacks observed before operation began to occur again 3 months later. The fact of postoperative recurrence suggests that the long history of the patient's seizures originating from AVM may have produced secondary epileptic foci.

Adolescent↗
PubMed1996

[Clinical analysis of embolism with left atrial myxomas].

We conducted a retrospective analysis examining the relationship between the tumor quality and the occurrence of systemic embolization in 16 patients who underwent surgical excision of the left atrial myxoma. Systemic embolization occured in 10 patients (63%) before surgery, in 5 of whom embolic episodes were the first manifestation of the tumor. Cerebral infarction had developed in 7 patients, TIA in 2, myocardial infarction in 2, limb ischemia in 2, and multiple infarctions in the kidney, adrenal gland, spleen and bone marrow in one. A permanent deficit remained in 6 patients (60%). Myxoma was a lobulated and gelatinous type in 9 (90%) of these patients with embolization and a solid type only in one case. When the dignosis of the left atrial myxoma with soft and fragile quality is made by echocardiography, surgical excision should be performed without delay to prevent systemic embolization.

Adolescent↗
PubMed1996

[Traumatic thoracic aortic rupture--diagnosis and surgical repair].

Fifteen cases of traumatic thoracic aortic rupture (TAR) were treated at St. Marianna University Hospital from December 1980 to July 1995. Causes of TAR were due to vehicle accidents in 14 patients and fall in one patient. On diagnosis, contrast-enhanced CT scan was routinely performed in the patients with blunt chest trauma associated with superior mediastinal widening, loss of the aortic knob or right shift of the trachea on the initial roentgenogram. When CT scan demonstrated specific signs for TAR, pseudoaneurysm formation and/or extravasation of the contrast dye, aortography was eliminated before operation. As a role, operation was performed on an emergency basis as soon as the diagnosis was confirmed. Four cases died due to intrapleural rupture before or immediately after thoracotomy. Nine (82%) of the 11 patients in whom operation was completed survived and are doing well. In one of the 4 patients who underwent operation with simple aortic cross-clamping; paraplegia developed after 30 minutes of spinal ischemia. Left heart bypass with the Bio-Pump without heparin or with an antithrombin agent, argatroban, was used in recent 6 patients. Use of left heart bypass with the Bio-Pump without anticoagulant or with argatroban appears to be promising as a safe adjunct in the repair of TAR, preventing fatal bleeding of other injured organs.

Adolescent↗
PubMed1996

[A case of atlanto-axial rotatory fixation associated with Jefferson's fracture].

The authors present a case of atlanto-axial rotatory fixation associated with Jefferson's fracture. A 52-year-old man was admitted to our hospital complaining of severe neck pain and torticollis after a traffic accident. Cervical x-ray films showed fracture of the atlas. CT scans demonstrated traumatic subarachnoid hemorrhage and atlanto-axial rotatory fixation. The patient was managed with skull traction and reposition was achieved. Although he was maintained in a halo device for 4 months, rotary fixation recurred. He underwent posterior fusion between the atlas and axis. We review the literature and discuss the diagnostic problems and methods of treatment for atlanto-axial rotatory fixation.

Atlanto-Axial Joint↗