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K Sano

Publications and source records attributed to K Sano.

At least 433 records · Page 24Linked to original sources
PubMed1992

Bromodeoxyuridine immunohistochemistry for evaluating age-related changes in the rat mandibular condyle decalcified by intravenous infusion.

Age-related changes in cell proliferation kinetics of the mandibular condyle were studied in Sprague-Dawley rats using bromodeoxyuridine (BrdUrd) immunohistochemistry in decalcified, paraffin-embedded tissues. Intraperitoneal injection of 40 mg/kg BrdUrd was given 1 hr before animal sacrifice. Continuous perfusion of EDTA solution via the left ventricle shortened the decalcification time. Immunohistochemical staining was performed with monoclonal anti-BrdUrd antibody. BrdUrd labeled cells, i.e., the S-phase cells, were clearly visible with well-preserved cytological detail. Their nuclei exhibited homogeneously stained granules. The labeling index in the intermediate zone of the condyle decreased with increasing age of the animals. This method is useful for evaluating physiological and pathological changes of the rat mandibular condyle as well as other bones and joints.

Aging↗
PubMed1992

[A preliminary study to determine the activity of topoisomerase II in human kidney cancer cells with DNA unknotting method].

For the purpose of examining the Topoisomerase II (Topo II) activity in human kidney cancer cells, we performed experiments with using DNA unknotting method. This method check relative Topo II activity with its conversion of knotted form P4 phage DNA to unknotted form. Our preliminary results demonstrate remarkable activity of Topo II with specific conversion of knotted form P4 DNA to unknotted form in human kidney cancer cells, YCR and ACHN. Moreover, addition of etoposide to the same experiment suppressed Topo II activity in a dose dependent manner. Our results suggest that kidney cancer has a certain amount of Topo II, a target for etoposide. We believe this method is useful to measure Topo II activity in cancer cells and to estimate chemotherapeutic potential of Topo II inhibitors including etoposide in human kidney cancers.

DNA Topoisomerases, Type II↗
PubMed1992

[Oxygen-conserving delivery system].

Three methods for improving oxygen delivery efficiency--transtracheal oxygen therapy (TTO), reservoir cannula, and demand-pulse oxygen delivery--are currently available. We discuss our experiences of TTO and its characteristics compared with the other two methods. Since 1988, we have tried to apply TTO to the candidates for home oxygen therapy (HOT) fulfilling the following criteria: 1) good activity and enthusiasm to daily life, 2) high oxygen flow rate with nasal cannula, 3) complicating nasal disorders such as chronic sinusitis, or 4) suffering complications from nasal cannula therapy. We used a disposable 8-Fr feeding tube for a trnastracheal catheter. Patients were taught to change their catheters themselves every day by simply removing the old and reinserting the new catheter. We have experienced nine patients on HOT with TTO. A half to a third of the flow rate of nasal cannular was required with TTO to achieve an equivalent PaO2 level. In cases with hypercapnea, a persistent significant increase of PaCO2 was not found. We measured arterial blood gases, changing the distance from the tract opening to the catheter tip, and it was suggested that in each case there may be an optimum distance to achieve the highest PaO2 level. Seven cases received TTO for more than 18 months, a mean of 30.2 months (range 19.3-48.9) and HOT for a mean of 26.6 months. They all maintained a high degree of enthusiasm for TTO. Two cases could return to work. Five cases enjoyed active daily lives, such as shopping, going out for recreation, travelling, and attending concerts.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Clinicobacteriological study of Pasteurella multocida infection as a zoonosis. (2)--Comparisons of P. multocida separated from patients and their pet dogs and cats].

A total of 17 strains of Pasteurella multocida, of which 13 were isolated from patients treated at Nihon University Itabashi Hospital or Nihon University Surugadai Hospital between April, 1984 and March, 1991 and 4 from 1 dog and 3 cats kept by the patients, were evaluated with respect to their biochemical properties, sensitivity to drugs, and serotype. The isolated strains were all considered to be Pasteurella multocida subsp. multocida because of the agreement of their responses to indole, sorbitol and dulcitol with those of this subspecies, except for 1 sorbitol-negative strain of Pasteurella multocida subsp. septica isolated from 1 patient who had been bitten by a cat. All the isolated strains showed high sensitivities to various drugs. The serotype was capsular type A, which is often observed in cats and dogs, in 7 strains, which consisted of 6 of the 7 strains derived from the airway of the patients and 1 of the 6 strains derived from bit or scratch wound. The remaining strains could not be classified. Five morphological types, namely 1, 3, 3.8, 6, and 8 were observed. In 2 patients, Pasteurella multocida subsp. multocida of the same serotype was also isolated from their cats. One of these patients had intimate contact with the cat including kissing. Our findings suggest that: 1) Pasteurella multocida subsp. multocida has been responsible for most conventional cases of Pasteurella multocida infection. 2) Strains isolated from patients differ in the capsular type according to the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Induction of smg p21/rap1A p21/krev-1 p21 gene expression during phorbol ester-induced differentiation of a human megakaryocytic leukemia cell line.

smg p21A and -B (smg p21s) are ras p21-like small GTP-binding proteins (G proteins) with the same putative effector domain as ras p21s. Both smg p21A mRNA and smg p21B mRNA were detected in CMK, a human megakaryocytic leukemia cell line, and their levels were markedly elevated by treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which caused the differentiation of this cell line into more mature megakaryocytes. The smg p21 protein molecules also increased during the TPA-induced differentiation of CMK cells. The mRNA level of glycoprotein IIb (GPIIb), a typical marker of the megakaryocytes, was increased by this treatment, but the time course of the increase in the smg p21 mRNA levels as more rapid than that of the increase in the GPIIb mRNA level. Ha-ras p21 mRNA was undetectable, but both Ki- and N-ras p21 mRNAs were detected in CMK cells and their levels were also increased during TPA-induced differentiation of CMK cells, although to a lesser extent than those of smg p21 mRNAs. Protein kinase C inhibitors inhibited the basal and TPA-induced smg p21A mRNA level, but cyclic AMP-elevating prostaglandin E1 or Ca(2+)-mobilizing ionomycin did not inhibit them. Cycloheximide enhanced the basal and TPA-induced smg p21A mRNA levels. Actinomycin D blocked the TPA-induced smg p21A mRNA levels, but showed no detectable effect on the elevated smg p21A mRNA level which was induced by pretreatment with TPA. A dramatic increase in the smg p21 mRNA levels was also observed in other leukemia cell lines during TPA-induced differentiation. These results suggest that TPA stimulated expression of the smg p21A gene, presumably through the action of protein kinase C at the transcriptional level rather than at the post-transcriptional level, in hematopoietic leukemia cells.

Alprostadil↗
PubMed1991

Expression and localization of smg p25A (= rab3A) in cultured rat hippocampal cells.

We have studied the expression of smg p25A and synaptophysin in cultured hippocampal neurons isolated from 5-day-old rat brain by an immunocytochemical technique. In a dispersed cell culture seeded on astrocyte monolayers, well-branching neurite proliferation was observed along with age in culture. The synaptophysin immunoreactivity was present in the neuronal cell bodies and neurites at 1 and 5 days in vitro (DIV) and was eventually localized to discrete areas along neurites at 15 DIV while the immunoreactivity in cell bodies became less prominent. On the other hand, the smg p25A immunoreactivity was observed in the neuronal cell bodies and neurites at 1 through 15 DIV. The immunoreactivity for smg p25A or synaptophysin was not observed in astrocytes and this finding was confirmed by an immunoblot analysis. These results indicate that smg p25A as well as synaptophysin is present exclusively in neurons and suggest that these two synapse-associated proteins have different sites of function and different kinetics of synthesis, transport, and/or turnover in cultured hippocampal neurons.

Animals↗
PubMed1991

Effects of dexamethasone on the expression of myelin basic protein, proteolipid protein, and glial fibrillary acidic protein genes in developing rat brain.

Effects of dexamethasone (DEX) on the relative abundance of myelin basic protein (MBP), proteolipid protein (PLP) and glial fibrillary acidic protein (GFAP) mRNAs in the developing rat brain were examined. After DEX (1.0 mg/kg body weight) or saline was administered intraperitoneally to 3-day-old rats for 7 consecutive days, wet weight, DNA content and the relative abundance of the glia-specific mRNAs in cerebrum and cerebellum were analyzed at postnatal days (P) 10, 20 and 30. DEX decreased both wet weight and DNA content in cerebellum more profoundly than in cerebrum. The appearance of MBP, PLP and GFAP mRNAs in cerebellum preceded that in cerebrum in the control group. In cerebrum, the relative abundance of MBP and PLP mRNAs was significantly less in the DEX group than that in the control group at P20 and P30. The relative abundance of the GFAP mRNA was significantly less in the DEX group than in the control group at P10 and P20, but there was no significant difference at P30. In cerebellum, a significant decrease in the abundance of MBP, PLP and GFAP mRNAs in the DEX group was observed only at P10 but not at P20 and P30. Our findings indicate that DEX suppresses expression of genes related to glial functions, especially myelination when administered in the early postnatal period.

Aging↗
PubMed1991

Effects of thyrotropin-releasing hormone on behavioral disturbances in middle cerebral artery-occluded rats.

The effects of thyrotropin releasing hormone (TRH) on behavioral and histological changes were studied in rats subjected to left middle cerebral artery occlusion. The drug was given i.p. once or several times a day from 1 week after occlusion for 2 weeks. A single administration of TRH (1 and 10 mg/kg) did not affect the neurological deficits, but recovery of the deficits was accelerated by multiple administration (7 times a day) of TRH and single administration (once a day) of YM-14673 (N alpha-[[(S)-4-oxo-2-azetidinyl]carbonyl]-L-histidyl-L-prolinamide dihydrate), a new TRH analogue with a longer half-life. Both YM-14673 and single (1 and 10 mg/kg) and multiple administration of TRH ameliorated the disturbance of passive avoidance learning. Neuronal degeneration in the cerebral cortex and striatum was not influenced by the administration of TRH. Thus, we found that neurological deficits and disturbance of passive avoidance learning behavior in middle cerebral artery-occluded rats could be ameliorated by administration of TRH.

Animals↗
PubMed1991

Production of infectious particles from defective human immunodeficiency virus type 1 (HIV-1)-producing cell clones by superinfection with infectious HIV-1.

A total of 81 cell clones persistently infected with the LAV-1 or HTLV-IIIB strain of human immunodeficiency virus type 1 (HIV-1) was isolated from cells which were obtained by serial passage of some proliferating MT-4 cells after a drastic cytolysis of most cells by HIV-1-infection. These cell clones were classified into 8 types (I to VIII) in terms of the expression of HIV-1 antigens, syncytium formation capacity, and reverse transcriptase activity and infectivity of virus particles in the culture fluid. Type I cell clones were producers of infectious HIV-1 particles, while types II to VIII cell clones did not produce infectious HIV-1 or were producers of uninfectious defective HIV-1 particles. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis (PAGE) showed that the gag precursor protein in L-2 cell clone (type IV) was not cleaved to mature gag proteins, while the env precursor protein on L-3 cell clone (type III) was not cleaved to mature env protein. H-7 cell clone (type VIII) did not express any HIV-1 antigen. All these cell clones after the superinfection with infectious HIV-1 synthesized intact gag and env proteins, which were, at least in part, related to the HIV-1 genome persistently present in the cell clones before the superinfection, resulting in production of infectious HIV-1. For example, it was found that L-2 cell clone contained a single copy of the LAV-1 genome per haploid cell and produced doughnut-shaped particles. On the other hand, the cell clone isolated from the L-2 cell clone superinfected with infectious HTLV-IIIB contained the integrated HTLV-IIIB genome in addition to the LAV-1 genome present before the superinfection, and produced intact HIV-1 particles in addition to doughnut-shaped particles from a single cell. These results indicate that complementation and/or genetic recombination events in the superinfected cells may account for the production of infectious intact HIV-1 virions.

Animals↗
PubMed1991

Differential expression of the N-myc, c-fos, and smg p25A genes in human neuroblastoma cells during neuronal and Schwannian differentiation.

We have examined expression of the N-myc, c-fos and smg p25A genes in two human neuroblastoma cell lines during their differentiation. The decrease in the N-myc gene expression and the increase in the c-fos gene expression are observed during the differentiation of NB-1 cells into neuronal cells and of GOTO cells into Schwann-type cells. On the other hand, the smg p25A, a ras p21-like small GTP-binding protein, gene expression is increased in NB-1 cells but not in GOTO cells during their differentiation, suggesting that smg p25A is closely associated with the neuronal phenotype of neuroblastoma cells.

Bucladesine↗
PubMed1991

Effects of exogenous hemin on the niacin content of aerobically grown Saccharomyces uvarum.

In Saccharomyces uvarum aerobically grown in the tryptophan-added medium, the niacin content started to increase when both tryptophan and glucose in the medium had almost been exhausted. In the kynurenine-added medium, the niacin production occurred immediately after incubation started. Hemin added to the medium enhanced total niacin production by increasing the amount of tryptophan metabolized via the kynureninase flux. The results suggest that the niacin biosynthesis from tryptophan was regulated by catabolite repression, which was alleviated by exogenously added hemin.

Aerobiosis↗
PubMed1991

Studies on heat treatment for immediate reimplantation of resected bone.

Extracorporeal heat treatment for devitalizing the tumour-infiltrated bone segment without destroying its regenerative potential was investigated for the purpose of immediate reimplantation of the resected bone. Effects of heat treatment on cell viability and bone inductive properties were studied in cultured tumour cells and animal models. Heat treatment at 65 degrees C for 30 to 120 minutes resulted in complete devitalization of cells, preserving osteogenetic properties of the allogenic bone implant in the rabbit. The results of the experiments indicate that this procedure has advantages in devitalizing the resected bone for its immediate reimplantation and justify clinical application. The clinical application of this heat treatment in 3 cases is presented.

Adult↗
PubMed1991

Application of magnetic resonance imaging and ultrasonography to preoperative evaluation of masseteric hypertrophy.

A case of unilateral masseteric hypertrophy in a 30-year-old man is described. Preoperative evaluation was performed by magnetic resonance imaging (MRI), computed tomography (CT) and ultrasonography (USG). MRI could delineate not only the border between medial and lateral layers of the masseter but also delineate the hypertrophic portion. MRI also provided more information in respect of the masseter muscle as well as the other masticatory muscles and the surrounding tissues than CT. USG was useful because of its real-time processing, especially in this case where facial asymmetry was emphasized during mastication. We resected the medial lower-half of the masseter intraorally based on these imagings and obtained a successful result.

Adult↗
PubMed1991

An epidemiological study of brain tumours in the elderly.

An epidemiological study of brain tumours in elderly Japanese was undertaken on the basis of a report from the All Japan Brain Tumor Registry. Thus, the recent status of brain tumours in elderly Japanese could be clarified. Accordingly, the formerly compiled characteristics of brain tumours in the elderly should more or less be revised. However, we are all still facing the same unfavourable prognosis of brain tumours in the elderly as before.

Adolescent↗
PubMed1991

Diversity of the cadherin family: evidence for eight new cadherins in nervous tissue.

To examine the diversity of the cadherin family, we isolated cDNAs from brain and retina cDNA preparations with the aid of polymerase chain reaction. The products obtained included cDNAs for two of three known cadherins as well as eight distinct cDNAs, of which deduced amino acid sequences show significant similarity with the known cadherin sequences. Larger cDNA clones were isolated from human cDNA libraries for six of the eight new molecules. The deduced amino acid sequences show that the overall structure of these molecules is very similar to that of the known cadherins, indicating that these molecules are new members of the cadherin family. We have tentatively designated these cadherins as cadherin-4 through -11. The new molecules, with the exception of cadherin-4, exhibit features that distinguish them as a group from previously cloned cadherins; they may belong to a new subfamily of cadherins. Northern blot analysis showed that most of these cadherins are expressed mainly in brain, although some are expressed in other tissues as well. These findings show that the cadherin family of adhesion molecules is much larger than previously thought, and suggest that the new cadherins may play an important role in cell-cell interactions within the central nervous system.

Adult↗