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Biomedical subjects

S Seno

Publications and source records attributed to S Seno.

At least 19 recordsLinked to original sources
PubMed2005

Use of real-time magnetic resonance image guidance in endoscopic sinus surgery.

We evaluated the effectiveness of magnetic resonance image (MRI) guidance using an optical tracking system (MRI-guided therapy: MRT) in performing endoscopic sinus surgery (ESS). The profiles of the fourteen patients in the present study were as follows: eleven with mucocele in the paranasal sinus, one with recurrent chronic sinusitis, one with maxillary cancer, and one with Graves' ophthalmopathy. Preparation of the MRT system required an additional 54 min in cases involving general anesthesia, and an additional 17 min in cases involving local anesthesia, in comparison with corresponding control groups undergoing ESS in a traditional operating room. We developed nonmetal probes that were visualized in a real-time mode and assistive devices for the optical tracking system that were equipped to avoid obstruction caused by surgical instruments as well as by the hands of surgeons. Using these unique devices, anatomic landmarks were visualized using the present MRT system. The prognosis of patients was favorable, and in particular, no patients with sinus mucocele showed a recurrence of their lesions. We concluded that the MRT system used here for performing ESS was beneficial, especially in terms of the intranasal marsupialization of sinus mucoceles and for the verification of orbital contents.

Journal Article↗
PubMed2001

[Japanese cedar pollen in house dust].

Caring for oneself against Japanese cedar pollinosis is important as well as receiving medical-care. Although the importance of avoiding pollen is described in the guideline for nasal allergy medical treatment, however, there is no information for effective dust cleaning for the home. This study examined how many cedar pollens were included in indoor dust in order to obtain basic data whether dust removal for cedar pollen is available for pollinosis suffers. As a result, the study found that there were many Japanese cedar pollens in indoor dust even before the pollen season. Cedar pollen increased with the increasing number of airborne pollen. The highest number of pollen found in one week was approximately 450 pollens in a square meter of a living room floor. The study concluded that cleaning is one of the best way to remove Japanese cedar pollens found in indoor dust.

Dust↗
PubMed2000

Endoscopic surgery for a parathyroid functioning adenoma resection with the neck region-lifting method.

Recently, endoscopic surgery has been applied to cervical exploration. We have developed new techniques for endoscopic neck surgery. We reported on a 53-year-old Japanese man with functioning parathyroid adenoma resected by endoscopic surgery with a neck region-lifting method. A 10-mm midline trocar for the endoscope and two 5-mm lateral trocars were inserted from the anterior chest wall to avoid neck scars. There were no intraoperative complications. The incisions were completely covered by the patient's undergarments.

Adenoma↗
PubMed2000

[IFOBT-positive gastric cancer].

Among 888 patients who underwent operation or endoscopic resection for gastric cancer (1994-1998), 75 patients, who had no colorectal disease or only small polyps 5 mm or less in diameter, were positive on the immunologic fecal occult blood test (IFOBT) (the positive group). They are compared with the other 813 patients (the negative group) as to the following 6 points: symptoms, presence of anemia, depth of invasion including macroscopic appearance, location, maximum diameter of lesions, and microscopic findings. The rate of positive-IFOBT gastric cancer was 8.4%. The average blood hemoglobin concentration was significantly lower in the positive group than in the negative group. Advanced cancers, especially type 2 and 3, were significantly more frequent in the positive group than in the negative group. The size of the lesions tended to be larger in the positive group than in the negative group. There was no difference between the groups as to symptoms, location, depth of invasion and microscopic findings. In conclusion, IFOBT-positive patients who have no colorectal disease or only small polyps 5 mm or less in diameter should be recommended to undergo upper gastrointestinal endoscopy.

Female↗
PubMed1998

BALB/c 3T3 cells co-expressing FGF-2 and soluble FGF receptor acquire tumorigenicity.

The physiological significance of the soluble fibroblast growth factor (FGF) receptors is not clear yet although they are present in blood, vitreous fluid and in the extracellular matrix of vascular endothelial cells. A hypothesis that they might help FGF-2 release from cells is very interesting because FGF-2 does not have clear secretion signal and the mechanism of the secretion of FGF-2 is still unclear. Single overexpression of FGF-2 is related neither to the secretion potential of the molecule nor to the tumorigenicity of the cells. In this report, BALB/c 3T3 cells transformed with the full length of human FGF-2 cDNA are further transformed with the cDNA coding the extracellular domain of human FGF receptor 1. The obtained transformants co-expressing FGF-2 and soluble FGF receptor are highly tumorigenic in nude mice, while the parental cells do not show any tumorigenicity. In the conditioned medium of the double-transformants, FGF-2 is immunologically detected. These results suggest that naturally produced soluble form of FGF receptor supports the release of FGF-2 from the cells and that over-expression of these two molecules leads to induce the malignant tumours in vivo.

3T3 Cells↗
PubMed1998

Regulation of tumor growth as a 'total mass' in mice: apoptosis as a major mechanism in altering growth rates of single and multiple coexisting tumor nodules.

Earlier studies have suggested that a solid tumor behaves, in its general pattern of growth, like a normal integrated organ. In this study, the growth patterns of spherically shaped tumor nodules are re-examined using an accurate tumor volume-measuring procedure, with the aim of investigating the possible role of apoptosis in regulating tumor growth. Observations revealed at least three distinct phases of growth: rapid growth phase I, slower growth phase II and 'stationary' phase III. Transition from one phase to the next was primarily due to an increase in the level of apoptosis and not to a decrease in the cell proliferation rate. The level of apoptosis, at a given phase, was similar in a single nodule and each of the multiple coexisting nodules of the same tumor line. However, temporal shifts in apoptosis levels caused early phase transition in coexisting nodules, such that their total volume was the same as that of a single nodule. It can be concluded that apoptosis appears to be a primary mechanism regulating tumor growth as a 'total mass', irrespective of whether the tumor exists in one or multiple nodules, if derived from the same tumor line.

3T3 Cells↗
PubMed1995

Recombinant human pancreatic ribonuclease produced in E. coli: importance of the amino-terminal sequence.

Human pancreatic ribonuclease 1 (hRNase 1) in the mature form has been produced in E. coli using T7 expression system. The recombinant hRNase 1 protein was solubilized from the inclusion bodies, refolded in glutathione redox system, and purified through chromatographic procedures by utilizing cation-exchange and reversed-phase columns. The ribonucleolytic activity of recombinant hRNase 1 was examined on yeast RNA and cytidylyl-3',5'-adenosine revealing the distinctive ribonucleolytic activity. The activity was perfectly inhibited by human placental RNase inhibitor. Truncation of 7 amino acid residues in the amino-terminal sequence resulted in much reduction in ribonucleolytic activity and in affinity to human placental RNase inhibitor with the disintegration of secondary structures of the protein observed by circular dichroism spectra. The present study has revealed the important contribution of the amino-terminal sequence of hRNase 1 to the characteristics of the protein.

Amino Acid Sequence↗
PubMed1994

Nucleotide sequence encoding human pancreatic ribonuclease.

A cDNA coding for human pancreatic ribonuclease was isolated from a pancreas cDNA library and sequenced. This cDNA (1620 bp) includes an entire open reading frame encoding mature protein (128 aa) following a signal peptide (28 aa) as well as 5'- and 3'-untranslated regions.

Amino Acid Sequence↗
PubMed1994

Gene ecology: a cis-acting gene-to-gene interaction due to the spatial arrangement of genes in chromosomes affects neighbouring transfected c-H-ras expression.

A cis-acting interference between gene activities, which occurs when two genes lie on the same DNA strand and have an intergenic distance less than a defined length, was previously deduced when chromosomal organizations of various higher eukaryote nuclear genes in clusters were compared. In order to investigate such an interference due to arrangement of genes along chromosomes, we have isolated a few cell lines which possessed (i) human mutated c-H-ras fused with the mouse mammary tumour virus long terminal repeat and (ii) the E. coli xanthine-guanine phosphoribosyltransferase (gpt) gene with the SV40 promoter, on the same or on different DNA strands, separated by a short intergenic distance or unlinked. Since the cancerous phenotype of a cell can be readily identified due to c-H-ras expression, we examined in these cell lines whether continuous c-H-ras expression, induced by dexamethasone, is disturbed through a cis-acting gene-to-gene interaction when the expression of the neighbouring gpt gene is enforced and as a result, the cancerous state of a cell is converted to the 'normal' state. The enforced expression of the neighbouring gpt gene was shown to alter c-H-ras expression, and thus reversible conversion of a cell between cancerous and normal states occurred only when the cell possessed an optimum number of the gene pair, in which both c-H-ras and the gpt gene were on the same DNA strand. This implies that the spatial arrangement of genes in chromosomes plays an important role in the regulation of gene expression in a cluster.

Animals↗
PubMed1992

Morphology of the kidney of the platypus (Ornithorhynchus anatinus: Monotremata).

The platypus kidney shows morphological similarities to those of other mammals. Macroscopically, the cortex is easily distinguishable from the fairly wide medulla. Within the medulla, no clear border is observed between the inner and outer zones. Light and transmission electron microscopically, the glomeruli show quite similar architecture to those of other mammals; however, the glomerular lobulation is very clear. The glomerular tufts are rather simple, but capillary lumen varies widely in size, which is one of the unique features of the platypus kidney. The urinary tubule is generally similar to that of human and other mammals in shape and segmentation; however, the staining specificities of histochemical reactions and the shape of epithelial cells of the Henle's loop differ from those of other mammals. The most conspicuous features are: 1) although no protein casts are found in the tubular lumina, epithelial cells of the proximal convoluted tubule (PCT) have numerous electron-dense vesicles as in human nephrotic kidneys; and 2) the platypus Henle's loop consists of the thick epithelial cells similar to the mammalian type nephron of birds. As compared to those of other mammals such as humans and rats, our observations suggest that the platypus kidney is less developed, in terms of evolution.

Animals↗
PubMed1991

Histochemical studies on the mechanism of macromolecule leakage across the glomerular capillary wall. Barrier effect of the anionic groups of the capillary wall against the serum protein leakage.

For the purpose of revealing the barrier effect of the anionic groups of glomerular capillary wall against the serum protein leakage, morphologic and histochemical observations were made on the rat kidney perfused in situ with three kinds of cationic macromolecules different in chemical characteristics followed by blood flow restoration. The polyethyleneimine perfusion resulted in the complete disapperance of ionized anionic groups of glomerular capillary and the massive protein leakage through glomeruli by blood flow restoration. Cationic ferric colloid perfusion induced moderate protein leakage, and avidin perfusion was less in neutralization effect of anionic groups and the protein leakage was of least. The protein leakage from glomeruli, however, was stopped or markedly suppressed soon after the blood flow restoration by the newly formed functioning anionic barrier probably by some particular serum protein deposition. The findings indicate that the deionization of the glomerular capillary wall will not be responsible for the persistent albuminuria.

Animals↗
PubMed1991

An optimum dose of c-H-ras is a prerequisite for hormone-dependent conversion of a cell between cancerous and normal states in tissue culture.

We have established a few cell lines which can be reversibly converted from cancerous to normal and vice versa by the addition to, or removal from the culture medium of glucocorticoid hormone. These cell lines were derived from mouse NIH 3T3 cells and possessed the integrated gene pairs on chromosomes, which are composed of human mutated c-H-ras fused with mouse mammary tumour virus long terminal repeat and E. coli xanthine-guanine phosphoribosyltransferase gene with the SV40 promoter. We have characterised these cell lines in order to elucidate an essential requirement for the conversion of the state of a cell. It was found that the presence of at least two to three copies of the gene pair per diploid genome are essential. An approximate threshold level of c-H-ras 1.6 kb RNA required for reversible conversion was estimated.

Animals↗
PubMed1991

Intestinal mucosa and intra-abdominal lymphoid tissues of the platypus, Ornithorhynchus anatinus.

The morphological features of the intestinal mucosa and intra-abdominal lymphoid tissues of the platypus were examined. The mucosal surface of the intestine was characterized by the formation of large folds instead of the finger-like villi found in placental mammals. The lamina propria of the mucosal fold was well developed and contained numerous lymphocytes, expressing the lymphoid nature which is characteristic of the lamina propria of mammalian intestines. Although numerous well-developed Peyer's patches were observed in the ileum, solitary lymphoid nodules could not be found anywhere in the small intestine. Other intra-abdominal lymphoid tissues, particularly mesenteric lymphoid nodules, were well developed. However, each nodule represented a single follicle in contrast to the mammalian mesenteric lymph node which is composed of numerous follicles fused together. On the basis of the above findings, the tissues in question are considered to be at an evolutionary level preceding that of placental mammals.

Abdomen↗
PubMed1991

Transport of ferritin from Kupffer cells to liver parenchymal cells. Morphological and immunocytochemical observations.

In attempting to determine the pathway of ferritin from Kupffer cells to liver parenchymal cells, anionic iron colloid particles of a ferric hydroxide-potassium polyvinyl sulfate complex (Fe-PVS) were injected intravenously into blood-depleted anemic rats. After iron loading, the process of ferritin formation and the daily change in the latter's distribution in the liver were studied by ultrastructural-immunocytochemical techniques. Three days after Fe-PVS injection, a mass of reaction products of ferritin was found in Kupffer cells, though not in the sinusoidal endothelial or parenchymal cells. Four days post-Fe-PVS injection, however, reaction products in Kupffer cells disappeared, while appearing in parenchymal cells. Observations at 3.5 days after the injection revealed heavy deposition of reaction products in the sinusoid and Disse's spaces as well. Electron microscopic observation of tissue sections treated with bismuth subnitrate taken at this stage revealed diffuse dispersion of ferritin particles in the cytoplasmic matrix of parenchymal cells as well as in the sinusoid and Disse's spaces. Ferritin particles were not found in the coated pits and vesicles of the Kupffer cells and parenchymal cells. Four days after injection, ferritin particles were found in clusters in the cytoplasm of the parenchymal cells and also in their lysosomal bodies. The results indicate that ferritin synthesized in Kupffer cells is released into sinusoidal and Disse's spaces and then accumulated in parenchymal cells.

Anemia↗
PubMed1990

Melano-macrophage centers in the aglomerular kidney of the sea horse (teleosts): morphologic studies on its formation and possible function.

In order to elucidate the process of the formation and possible function of the renal "melano-macrophage centers (MMC)" of fish, light and electron microscopic observations were carried out on the aglomerular kidney of the sea horse, Hippocampus kuda BLEEKER, injected with antigenic horse-spleen ferritin (AF) and nonantigenic carbon particles (CP). Kidneys of the sea horse have well-developed hemopoietic foci in the interstitial tissues surrounding the bundles of renal tubules. Each hemopoietic focus has a small artery in the central area and is framed with the densely arranged sinusoids lined with monolayered macrophages which have no melanin pigments. In the hemopoietic foci free macrophages (M phi) were hardly found, but large clusters of MMC filled with densely packed masses of cell debris with some melanin pigments were encountered. Some of them had degenerated M phi with fibrotic change surrounded by fibroblasts. AF and CP injected intraperitoneally entered quickly into blood vessels and were taken up actively by the sinusoidal M phi. The M phi full of AF or CP left the sinusoidal wall and moved gradually into hemopoietic foci to form the MMC or to fuse with the preexisting MMC. The melanophores in the interstitial connective tissue joined to form the MMC. No specific histologic change suggestive of immune response to the AF was present in and around the MMC. The results indicate that the MMC of fish should be only the aggregates of M phi to digest the ingested materials effectively. The process of formation of MMC and their possible function is discussed.

Animals↗
PubMed1990

[Extended hypothermic heart-lung preservation system for cardiopulmonary preservation with retrograde coronary sinus perfusion and lung immersion].

One major restriction of clinical heart-lung transplantation has been the inability to provide extended hypothermic organ preservation. We examined whether core-cooling, retrograde heart perfusion and lung immersion could provide adequate cardiopulmonary preservation. Hence, donor dogs were placed on cardiopulmonary bypass, and rapidly cooled to 15 degrees C. Then heterotopic heart unilateral left lung transplantations were performed. In control group I (n = 5), hearts and lungs were harvested following core-cooling and cardioplegic arrest, and transplanted immediately. In experimental group II (n = 5), heart-lung blocks were similarly excised but stored at 4 degrees C for 12 hours and then transplanted. During preservation, the lungs were immersed in the extracellular solution. For the heart, non-recirculating retrograde coronary sinus perfusion was performed with oxygenated intracellular solution containing perfluorochemicals. Myocardial function determined by the ratio of end-systolic pressure to end-systolic dimension in the experimental group was similar to that in controls. Although pulmonary vascular resistance and extravascular lung water of the experimental group was higher than those in control group, arterial oxygenation was similar in both groups. Thus, extended heart-lung preservation with core-cooling, retrograde heart perfusion and lung immersion technique could be achieved for heart-lung transplantation.

Animals↗