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Biomedical subjects

Y Ohmori

Publications and source records attributed to Y Ohmori.

At least 19 recordsLinked to original sources
PubMed1997

Comparison of three nonviral transfection methods for foreign gene expression in early chicken embryos in ovo.

By using three nonviral transfection methods, i.e., microparticle bombardment, lipofection and electroporation, the transfection efficiency and the expression intensity of a lacZ reporter gene were compared in developing chicken embryos in ovo. Of the three transfection methods employed, electroporation conferred the strongest expression of the bacterial lacZ gene with similar transfection efficiency. The results suggest that as far as transient gene expression is concerned, electroporation would provide a useful and efficient nonviral means of foreign gene transfection to somatic cells of living chicken embryos in ovo.

Actins↗
PubMed1996

Cells of origin of spinal projections from the paraventricular nucleus (PVN) of the hypothalamus in the chicken.

Hypothalamic neurons projecting to the lumbar (lumbar-neurons) and sacral (sacral-neurons) segments were retrogradely labeled by injections of fluorescent axonal tracers (FITC-WGA, TRITC-WGA) into both the lumbar and sacral segments. Labeled neurons were distributed in the principal part of the paraventricular nucleus (PVN), but not in the pars dispersa of this nucleus. Of these neurons, some small and oval-shaped neurons (about 10 microns in diameter) in a middle part of the PVN were observed to be labeled by both FITC-WGA and TRITC-WGA (lumbosacral-neurons) suggesting double projections to lumbar and sacral segments.

Animals↗
PubMed1996

Projections of neurons in the intestinal nerve of Remak to the chicken intestine.

To date, the exact site of the extrinsic postganglionic neurons innervating the intramural plexuses in the chicken intestine is unknown. In this study, neurons in the intestinal nerve of Remak (INR) were immunohistochemically labelled by injecting cholera toxin subunit B (CTb) into each one of the jejunal, ileal, cecal and rectal walls. The CTb-immunoreactive (IR) neurons were counted, and some sections from the rectal portion of INR (rectal INR) were also immunostained for either tyrosine hydroxylase (TH) or methionine enkephalin (mENK). Following injection of CTb into the jejunum or ileum, only a few CTb-IR neurons were found in the jejunal or ileal part of INR caudal to the injection site. Following injection into the more caudal intestine, CTb-IR neurons were seen in the rectal INR. Of the 3490 CTb-IR neurons that were counted in the rectal INR, 40% projected into the rostral rectum, 24% into the caudal rectum, 17% into the ileum, 10% into the cecum and only 9% into the middle rectum. Rostrocaudally dividing the rectal INR into three parts, one third of the CTb-IR neurons in the rostral part projected into the rostral rectum, the majority of CTb-IR ones in the middle part innervated the rostral rectum, and half of CTb-IR neurons in the caudal part ran into the caudal rectum. Consequently, the rostral rectum received the densest innervation, and almost all the neurons in the rectal INR exhibited an ascending projection. By double labelling, CTb-IR neurons containing TH or mENK were observed in the rectal INR after the rectal injection. The mENK-IR neurons localized in middle and caudal parts of rectal INR amounted to one third of the total CTb-IR neurons, and mainly projected into the rostral and caudal rectum. TH-and mENK-immunonegative neurons were restricted to the rostral part of rectal INR and the more rostral level.

Animals↗
PubMed1996

IL-4-induced expression of the IL-1 receptor antagonist gene is mediated by STAT6.

IL-4 alone or in cooperation with LPS can induce the expression of the gene encoding the secreted-type IL-1 receptor antagonist (sIL-1ra) in mononuclear phagocytes. To determine the nuclear signaling mechanisms involved in this response, the region flanking the transcription start site of the human sIL-1ra gene was placed upstream of the luciferase reporter gene, and the function of specific sequence elements was analyzed following transient transfection in the macrophage-like cell line RAW264.7. A region located between -250 and -200 bases relative to the transcription start site was necessary for response to IL-4 alone and for cooperation between IL-4 and LPS. This 50-bp region contains two inverted repeat elements that represent potential binding sites for members of the signal transducer and activator of transcription (STAT) gene family (STAT-binding elements (SBEs)). Site-directed mutagenesis of the distal SBE abolished IL-4 responsiveness, and multiple copies of this motif were able to confer IL-4 sensitivity to luciferase expression in the context of a heterologous (herpes virus thymidine kinase) promoter. Mutation of the proximal SBE in the intact IL-1ra promoter had little or no effect on response to IL-4, and this sequence motif was inactive when examined alone. Electrophoretic mobility shift assays using an oligonucleotide corresponding to the distal SBE identified a single binding activity that was detected in nuclei within 15 min of IL-4 treatment and that was recognized by Ab to STAT6. These results indicate that IL-4-induced STAT6 is required for IL-4-induced transcriptional activation of the sIL-1ra gene.

Animals↗
PubMed1996

LPS does not directly induce STAT activity in mouse macrophages.

Induction of gene expression in cytokine-treated cells involves the protein tyrosine kinase-dependent activation of members of the STAT family of transcription factors. To determine if lipopolysaccharide (LPS) might activate one or more STAT factors, nuclear extracts from LPS-treated RAW264.7 macrophages were assayed for STAT-like DNA binding activity using oligonucleotides recognized by different members of this protein family. Within 30 min a single LPS-inducible DNA-protein complex was detected using three separate oligonucleotides. This activity was not reactive with anti-STAT antibodies and was subsequently identified as composed of the NF kappa B components NF kappa B1 and Rel-A. Thus, LPS does not directly stimulate STAT factors with known sequence-specific DNA binding activity.

Animals↗
PubMed1996

Radioiodinated diacylglycerol analogue: a potential imaging agent for single-photon emission tomographic investigations of cerebral ischaemia.

Phospholipid metabolism is closely related to membrane perturbation in cerebral ischaemia. We investigated in vivo topographical lipid metabolism using an iodine-123-labelled diacylglycerol analogue, (1-(15-(4-iodine-123-iodophenyl)-pentadecanoyl)-2-stearoyl-rac-gly cerol) (123I-labelled DAG), in a middle cerebral artery (MCA) occlusion model with the aim of positive imaging of ischaemic insult. Sprague-Dawley rats underwent coagulation of the MCA to induce permanent occlusion. MCA occlusion times prior to injection of 123I-labelled DAG ranged from 15 min to 14 days. Each rat was injected with 11-37 MBq of 123I-labelled DAG via a tail vein. After 30 min, in vivo autoradiographs were reconstructed. Scanning of the living rat brain in this MCA occlusion model was performed using a gamma camera with a pinhole collimator. Cerebral infarctions were recognized in the frontal cortex, the parietal cortex and the lateral portion of the caudate-putamen by 2,3,5-triphenyltetrazolium hydrochloride staining. In infarcted regions (region 1), 123I-labelled DAG incorporation showed a slight decrease up to 12 h; it then increased up to 6 days and decreased thereafter. In peri-infarcted regions (region 2), the incorporation showed almost no change up to 12 h, then increased up to 5-6 days and decreased thereafter. In other regions (region 3), the incorporation showed no change. Lipid analysis showed that 123I-labelled DAG was metabolized to 15-(4-iodine-123-iodophenyl)-pentadecanoic acid by DAG lipase and to 123I-labelled phosphatidylcholine. Scanning of the ischaemic region showed higher accumulation than on the non-lesioned side. We established a method to visualize ischaemic foci as positive images. The early changes in 123I-labelled DAG incorporation were closely related to DAG lipase, which degraded the accumulated intrinsic DAG, and increased 123I-labelled DAG incorporation in the chronic stage involves several aspects of neural destruction in the process of autolysis. It is concluded that the reported method could have a clinical future.

Animals↗
PubMed1996

Chronological positron emission tomographic study of severe diffuse brain injury in the chronic stage.

Cerebral blood flow and metabolism were investigated in five patients with severe diffuse brain injury in the chronic stage, using positron emission tomography (PET). Regional cerebral blood flow, regional oxygen extraction fraction, regional cerebral blood volume, regional cerebral metabolic rate for oxygen, and regional cerebral metabolic rate for glucose were measured bilaterally in the frontal, temporal, occipital, and parietal gray matter, as well as the white matter of the centrum semiovale. In 4 of 5 patients, a follow-up PET study was also performed. In three cases, below-normal regional cerebral blood flow and regional cerebral metabolic rate for oxygen values accompanied by above-normal regional oxygen extraction fraction values, as well as low metabolism, were demonstrated in the initial PET studies. In two of three cases, clinical improvements were observed, and follow-up PET data also improved. These findings suggest that chronological PET studies may be able to assess quantitatively clinical improvements in patients with diffuse brain injury.

Adult↗
PubMed1996

Muscle representation within the hypoglossal nucleus of the chicken studied by means of horseradish peroxidase.

The distribution in the chicken of motoneurons innervating the hyolingual muscles, i.e. the Mm. hyoglossus rostralis (HR), hyoglossus obliquus (HO), ceratoglossus (CG), interceratobranchialis (CB), stylohyoideus (YH), serpihyoideus (PH) and cricohyoideus (CR), and the laryngotracheal muscles, comprising the Mm. tracheolateralis (TL), cleidohyoideus (CL) and sternotrachealis (ST), was examined by retrograde transport of horseradish peroxidase conjugated with wheat-germ agglutinin. Labelled motoneurons are only found in the hypoglossal nucleus. The rostrocaudal distributions of motoneurons projecting to hyolingual muscles are restricted in the hypoglossal nucleus cranial to the obex, and those projecting to laryngotracheal muscles are distributed in the more caudal part of hypoglossal nucleus. Detailed analysis of the data showed that the most rostrally positioned motoneurons in the hypoglossal nucleus supplied to the PH, followed by the CG, CB, HR, YH, HO, CR, TL, CL and ST in that order, overlapping each other. In the hypoglossal nucleus motoneurons innervating the PH and YH have the smallest perikarya. Of the motoneurons in the hypoglossal nucleus, those supplying the laryngotracheal muscles (CL and TL) have the largest perikarya. Motoneurons innervating the other muscles are intermediate in size.

Animals↗
PubMed1996

Anatomical localization of sympathetic postganglionic and sensory neurons innervating the pancreas of the cat.

Sympathetic postganglionic and sensory neurons were labeled by injecting a mixed solution of horseradish peroxidase and wheat germ agglutinin conjugated horseradish peroxidase into the splenic portion or the duodenal portion of the cat pancreas. Labeled postganglionic neurons (about 25,000 cells) were located bilaterally in the celiac and cranial mesenteric ganglia (91%), mainly in celiac ganglia, and in the paravertebral ganglia T5 to L7 (9%), especially in T13 to L2. Labeled sensory neurons (about 2,700 cells) were found bilaterally in the dorsal root ganglia T3 to L5, chiefly in T10 to L1. Some differences were found in the localization of labeled postganglionic and sensory neurons between the two portions of the pancreas. Injection in to the splenic portion revealed more labeled neurons in ganglia on the left side, while injection into the duodenal portion gave rise to a greater number of labeled neurons on the right side. Paravertebral and dorsal root ganglion cells innervating the splenic portion were concentrated in fewer ganglia than those supplying the duodenal portion. Compared to the splenic portion, the duodenal portion tended to be innervated by more cranially located neurons in paravertebral and dorsal root ganglia. These neurons probably control the secretion of the endocrine and exocrine pancreas, but the differences in the localization of the labeled neurons between the two portions may be related to the different intraabdominal positions of the two portions of the pancreas.

Animals↗
PubMed1996

Immunohistochemical studies of neural elements in pancreatic islets of the cat.

The cat pancreas has a complex neural supply comprising adrenergic, cholinergic and peptidergic innervations. To elucidate the localization of neuropeptides and enzymes in neural elements of the cat pancreatic islets, single or double immunohistochemical staining was performed using avidin-biotin-peroxidase complex and/or peroxidase-antiperoxidase methods. In intrapancreatic ganglia, numerous galanin (Gal)- or vasoactive intestinal polypeptide (VIP) immunoreactive (IR) ganglion cells were seen. Many nitric oxide synthase (NOS)- or cholecystokinin (CCK). IR and a few bombesin (Bom)- or substance-P (SR)-IR ganglion cells were also observed. Intrapancreatic ganglion cells were surrounded by numerous VIP- or SP-IR, many Bom- or neuropeptide Y (NPY)-IR, several calcitonin gene-related peptide (CGRP)- or peptide histidine isoleucine IR and a few NOS- or CCK-IR nerve terminals. In pancreatic islets, many VIP-IR nerve terminals were located predominantly around insulin (Ins)-IR cell masses and many tyrosine hydroxylase-IR nerve terminals were demonstrated in the core of Ins-IR cell masses as well as around them. Gal-, NPY-, SP- or CGRP-IR nerve terminals were found much more frequently within Ins-immunonegative cell areas than in Ins-IR cell masses. These observations may provide a morphological basis for the possible transmitting or modulating role of neuropeptides in pancreatic islets of the cat.

Animals↗
PubMed1996

A case report of rectal schwannoma.

We experienced a case of rectal schwannoma which was diagnosed before surgery. In this paper we have described this rare case and have discussed a number of similar cases reported in the literature.

Aged↗
PubMed1996

[Comparative clinical study of adjuvant postoperative chemotherapy (5-FU, Tegafur, 5-FU + MMC) in curatively resected cases of gastric cancer. Study Group on 5-FU Oral Adjuvant Chemotherapy in Gastric Cancer].

A multi-center collaborative study was conducted in curatively resected gastric cancer patients at Stages II and III to compare oral 5-FU (Group A), oral Tegafur (Group B) and i.v. MMC + oral 5-FU (Group C). From May 1982 to April 1985, 1,012 cases were enrolled at 55 institutions. Some 138 (13.8%) were excluded, and 874 were analyzable. In the analysis of background factors, Group B had more cases with tumor of large diameter and advanced Stage. Adverse effects were relatively mild in all groups, and there was no problem in drug tolerance. Five-year survival rate was 67.6%, 62.4% and 68.6% in Groups A, B and C, respectively, reflecting no significant difference among them. It was 85.0%, 83.0% and 81.1% in Stage II and 52.5%, 51.0% and 59.0% in Stage III of Groups A, B and C, respectively. No significant difference was found, but Stage III of Group C showed a slightly higher survival rate. Supportive clinical study will be required to assess the usefulness of MMC as an introduction therapy. We found no difference in efficacy between 5-FU and Tegafur as maintenance therapy. The life-prolongation effect of fluoropyrimidines in comparison with surgery alone should be studied separately.

Adult↗
PubMed1996

Immunohistochemical studies on the intramural nerve in the chicken intestine.

The distribution in the chicken intestine of neuropeptide-immunoreactive (IR) ganglion cells and nerve fibres was investigated immunohistochemically. There were four kinds of ganglion cells: vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, galanin (GAL)- and somatostatin (SOM)-IR cells in the submucous plexus (SMP) of the whole intestine and in the myenteric plexus (MYP) in the small intestine excluding VIP-IR ones. These peptide-containing fibres were found consistently but their distribution was variable in the mean areas in different regions of the intestinal wall. They seemed to be intrinsic. Comparing the jejunum and rectum in density and variation, the characteristics of innervation were as follows: villi in both intestines received more VIP-IR fibres than the other three which showed no significant difference. Crypts were surrounded with SP-IR fibres; these were denser than the other three in the jejunum compared with the rectum. The mean areas of SOM- and GAL-IR fibres were four and six times larger than those in the rectum, respectively. The SMP was supplied with the six kinds of neuropeptide-IR fibres, and VIP-IR fibres were dominant in both sides. Areas of VIP-, SP- and SOM-IR fibres were about two times greater than in the jejunum. The area of VIP-IR fibres in the circular muscle was significantly larger than that of the other four in both intestines; their density in the rectum was bout two times higher than in the jejunum. The mean area of SP-IR fibres in jejunal circular muscle was 14 times larger than that in the rectum. The MYP was supplied with seven kinds of neuropeptide-IR fibres except that methionine enkephalin-IR was absent from the rectum. Of these seven fibres, SP- and VIP-IR fibres in the jejunum had the largest areas. However, GAL-IR fibres in the jejunum were about four times denser than in the rectum. We conclude that the jejunum is characterized by the dense distribution of neuropeptide-IR fibres in crypts and MYP whereas in the rectum they occur in SMP and circular muscle. Fig. 15 summarizes the connections described in the present study.

Animals↗
PubMed1996

Spontaneous regression of intracranial arteriovenous malformation on PET.

We report a case of spontaneous regression of intracranial arteriovenous malformation (AVM) detected by PET in a 57-yr-old woman who had suffered repeated ruptures of the AVM at 28, 30 and 31 yr of age associated with pregnancy. The rupture at this hospitalization was the most critical, and after repeated ruptures for 1 mo, the AVM regressed spontaneously. The decreased cerebral blood volume (CBV) in the AVM indicated regression. The flow-to-volume (CBF/ CBV) ratios surrounding the AVM increased. The metabolic rate for oxygen (CMRO2) did not correlate with her improved neurological status, and an imbalance between CBF and CMRO2 was recognized.

Cerebrovascular Circulation↗
PubMed1996

Cerebral hemodynamics and metabolism of severe diffuse brain injury measured by PET.

Cerebral hemodynamics and metabolism in three patients with severe diffuse brain injury were measured 10 days after onset using PET. In this study, regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF), cerebral blood volume (rCBV), cerebral metabolic rate for oxygen (rCMRO2), cerebral metabolic rate for glucose (rCMRglc) and cerebral metabolic ratio (rCMRO2/rCMRglc) were measured. The Glasgow Coma Scale scores on admission were 4, 5 and 5, respectively, and CT on admission showed typical findings of diffuse brain injury. As a result, PET revealed misery perfusion and hyperglycolysis in Patient 1 and matching low perfusion and low glucose metabolism in Patients 2 and 3. Although Patient 1 died, Patients 2 and 3 had good recoveries. We speculate that a long-lasting anaerobic state, indicated by a high OEF value and low metabolic ratio, is an important undesirable factor related to the outcome.

Adolescent↗
PubMed1995

Two structurally distinct kappa B sequence motifs cooperatively control LPS-induced KC gene transcription in mouse macrophages.

The mouse KC gene is an alpha-chemokine gene whose transcription is induced in mononuclear phagocytes by LPS. DNA sequences necessary for transcriptional control of KC by LPS were identified in the region flanking the transcription start site. Transient transfection analysis in macrophages using deletion mutants of a 1.5-kb sequence placed in front of the chloramphenicol acetyl transferase (CAT) gene identified an LPS-responsive region between residues -104 and +30. This region contained two kappa B sequence motifs. The first motif (position -70 to -59, kappa beta 1) is highly conserved in all three human GRO genes and in the mouse macrophage inflammatory protein-2 (MIP-2) gene. The second kappa B motif (position -89 to -78, kappa B2) was conserved only between the mouse and the rat KC genes. Consistent with previous reports, the highly conserved kappa B site (kappa B1) was essential for LPS inducibility. Surprisingly, the distal kappa B site (kappa B2) was also necessary for optimal response; mutation of either kappa B site markedly reduced sensitivity to LPS in RAW264.7 cells and to TNF-alpha in NIH 3T3 fibroblasts. Although both kappa B1 and kappa B2 sequences were able to bind members of the Rel homology family, including NF kappa B1 (P50), RelA (65), and c-Rel, the kappa B1 site bound these factors with higher affinity and functioned more effectively than the kappa B2 site in a heterologous promoter. These findings demonstrate that transcriptional control of the KC gene requires cooperation between two kappa B sites and is thus distinct from that of the three human GRO genes and the mouse MIP-2 gene.

Animals↗
PubMed1995

Rapid incorporation of carbon-11-labeled diacylglycerol as a probe of signal transduction in glioma.

We have synthesized and characterized a positron-emitting carbon-11-labeled 1,2-diacylglycerol to study phosphoinositide turnover in tumor cells. Rapid incorporation of the 1,2-diacylglycerol was observed in the C6 glioma cell line. The incorporated lipid fraction consisted chiefly of phosphoinositide pool and another phospholipid pool in the proliferative state. When the state was inhibited by (-)-3D-3-deoxy-3-fluoro-myo-inositol, incorporation into the phosphoinositide pool decreased selectively. This suggested that phosphoinositide turnover is the leading regulator of tumor proliferation potential. On the basis of the concept of carbon-11-labeled 1,2-diacylglycerol as a specific probe for visualizing the tumor signal transduction in vivo, we obtained proliferating images of implanted C6 glioma cells in the rat brain by autoradiography and visualized the proliferation signal in human glioma by positron emission tomography.

Animals↗