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Biomedical subjects

K Furuya

Publications and source records attributed to K Furuya.

At least 91 records · Page 5Linked to original sources
PubMed1998

Faithful anaphase is ensured by Mis4, a sister chromatid cohesion molecule required in S phase and not destroyed in G1 phase.

The loss of sister chromatid cohesion triggers anaphase spindle movement. The budding yeast Mcd1/Scc1 protein, called cohesin, is required for associating chromatids, and proteins homologous to it exist in a variety of eukaryotes. Mcd1/Scc1 is removed from chromosomes in anaphase and degrades in G1. We show that the fission yeast protein, Mis4, which is required for equal sister chromatid separation in anaphase is a different chromatid cohesion molecule that behaves independent of cohesin and is conserved from yeast to human. Its inactivation in G1 results in cell lethality in S phase and subsequent premature sister chromatid separation. Inactivation in G2 leads to cell death in subsequent metaphase-anaphase progression but missegregation occurs only in the next round of mitosis. Mis4 is not essential for condensation, nor does it degrade in G1. Rather, it associates with chromosomes in a punctate fashion throughout the cell cycle. mis4 mutants are hypersensitive to hydroxyurea (HU) and UV irradiation but retain the ability to restrain cell cycle progression when damaged or sustaining a block to replication. The mis4 mutation results in synthetic lethality with a DNA ligase mutant. Mis4 may form a stable link between chromatids in S phase that is split rather than removed in anaphase.

Anaphase↗
PubMed1998

Transcription factors and osteoblasts.

Transcription factors play a key role in determination of the fate of the cells in osteoblastic and chondrocytic lineage. A runt family member, Cbfa, is indispensable for osteoblastic differentiation. Sox 9 and scleraxis are involved in the phenotypic expression in chondrocytes and the cells of early stage connective tissues. These transcription factors will give us a clue to unravel interaction of these known and yet unknown transcription factors to fully understand the mechanisms of skeletal cells ' differentiation and regulation of their functions.

Animals↗
PubMed1998

Prognostic and Therapeutic Implications of the MIB-1 Labeling Index in Breast Cancer.

BACKGROUND: Assessment of tumor proliferative activity is considered to be the most powerful prognostic factor aside from axillary lymph node status. The purpose of this study is to assess the clinical value of measurement of proliferative activity using the MIB-1 labeling index in patients with breast cancer. METHODS: Surgical specimens from 36 patients with benign breast disorders and146 patients with breast cancer were investigated. The MIB-1 labeling index wasdetermined on the specimens stained by immunohistochemical methods as much as possible. Clinical factors associated with the MIB-1 labeling index were reviewed. RESULTS: The MIB-1 labeling index for non-proliferative disorders, proliferative disorders, and breast cancer was 3.4 +/-1.9%, 8.9 +/-6.2% and 20+/-12%, respectively. The MIB-1 labeling index and tumor size, lymph node metastasis status, and clinical stage according to the TNM classification correlated significantly. Survival rate was inversely correlated with the MIB-1 labeling index. No patientwith an MIB-1 labeling index of less than 10% had lymph node metastases, and all are alive without recurrence. Patients with an MIB-1 labeling index of over 30% had an extremely poor prognosis. CONCLUSION: The MIB-1 labeling index is very useful for predicting both either extremely good or extremely poor prognosis, and axillary lymph node metastasis

Journal Article↗
PubMed1998

Potentiation by isoproterenol on carbachol-induced K+ and Cl- currents and fluid secretion in rat parotid.

Isoproterenol (IPR) and 8-(4-chlorophenylthio)-cyclic AMP (cpt-cAMP) enhanced carbachol (CCh)-induced fluid secretion from rat parotid glands, but had no effect by themselves. The enhancement by IPR was blocked by propranolol. In dispersed parotid acinar cells, IPR and cpt-cAMP potentiated CCh-induced K+ and Cl- currents (IK and ICl). IPR at the concentration of 0.1 microM significantly potentiated the CCh-induced increase in intracellular Ca2+ concentration ([Ca2+]i), but 1 mm cpt-cAMP did not. The incidence of the potentiation by IPR in CCh-induced Mn2+ entry was 31% and that by cpt-cAMP was 21%. The potentiation by IPR in the ionic currents and the [Ca2+]i was suppressed by propranolol. These results suggest that the CCh-induced fluid secretion from rat parotid glands is enhanced by IPR through the potentiation of IK and ICl mainly by the increased cyclic AMP level and partially by the potentiated Ca2+ influx and [Ca2+]i increase, and that IPR is more effective than cpt-cAMP in the enhancement of the CCh-induced [Ca2+]i increase.

Animals↗
PubMed1998

A case of sarcoidosis that developed three years after the onset of hard metal asthma.

A 23-year-old man who worked at a hard metal factory from 1988 had developed bronchial asthma in 1990. He was diagnosed as having bronchial asthma by inhalation challenge with cobalt. He never developed a severe attack after that by avoiding inhalation of cobalt. In 1993, he developed iridocyclitis, and his chest radiograph showed bilateral hilar lymph node swelling. He was diagnosed as having sarcoidosis with pathological certainty and an increased serum angiotensin-converting enzyme (ACE) level. On second admission, an inhalational challenge with cobalt resulted in no significant decrease of FEV1. Cobalt is well known to cause occupational asthma and other interstitial lung diseases. Although we could not get clear evidence suggesting an association between the sarcoidosis and his history of cobalt exposure, there is a possibility that changes in the immune reaction to cobalt might explain the improvement of asthma followed by sarcoidosis in this case.

Adult↗
PubMed1998

Thoracotomy for a patient with Stevens-Johnson syndrome: report of a case.

Stevens-Johnson syndrome (SJS) is an uncommon eruptive disorder of the skin and mucous membranes with systemic manifestation. It is extremely unusual for patients with a past history of SJS to present with indications for surgery necessitating thoracotomy. We describe herein the perioperative management of a patient with SJS who underwent surgery for a spontaneous pneumothorax.

Female↗
PubMed1998

Performance of adhesive bone cement containing hydroxyapatite particles.

A new acrylic bone cement which can adhere to both bone and prostheses was developed based on a methyl methacrylate (MMA) monomer containing 4-methacryloyloxyethyl trimellitate anhydride (4-META) as adhesion promoting agent. Moreover, hydroxyapatite (HA) particles were introduced into the 4-META cement as a bone compatible filler. The mechanical strengths of an acrylic bone cement without 4-META decreased drastically with an increase in the percentage of HA particles in the cement. However, the mechanical strengths of the HA-containing 4-META cement did not change in the same way as that of the 4-META cement without HA due to adhesion between the cement HA particles and matrix. The HA particles did not affect the adhesion of the 4-META cement to bone and metals. Implantation of the 4-META cement and the HA-containing 4-META cement in animals demonstrated that these cements did not disturb bone ingrowth and the new bone was able to contact the cement directly. The 4-META cements, with and without HA particles, could adhere to bone in vivo.

Biocompatible Materials↗
PubMed1998

Comparison of the expression of two immediate early gene proteins, FosB and Fos in the rat preoptic area, hypothalamus and brainstem during pregnancy, parturition and lactation.

Medial preoptic area (MPA), supraoptic nucleus (SON), magnocellular (MaPVN) and parvocellular (PaPVN) paraventricular hypothalamic nuclei, and mesencephalic lateral tegmentum (MLT) are involved in maternal behavior, parturition and lactation. This study investigated the FosB and Fos immunoreactivity in these regions of virgin, pregnant, parturient, lactating, and lactating-arrested rats. The patterns of FosB and Fos expression were compared between the sections taken from the same animals. Quantitative immunohistochemistry revealed a significant increase in the numbers of FosB-positive neurons in the MPA, SON, MaPVN, and MLT of parturient and lactating females as compared with pregnant or virgin animals. In lactating rats, the numbers of FosB-positive neurons in the MPA, PaPVN, and MLT were increased, but the numbers in the SON and MaPVN were decreased as compared with parturient females. Many Fos-positive neurons were also seen in parturient and lactating rats, and the patterns of Fos expression in each region were quite similar to those of FosB. Moreover, double-labeling immunohistochemistry revealed that: (1) many FosB-positive nuclei were observed in oxytocin and vasopressin neurons of the SON and PVN in parturient rats; (2) within FosB-positive neurons, 89.5% in the MPA, 86.8% in the MLT of parturient rats, and 92% in the MPA and 90.8% in the MLT of lactating animals were also Fos-positive. Only a small number of FosB and Fos-positive neurons were seen in females that were killed in the early stage of parturition. Removal of the litters immediately after parturition completely eliminated FosB and Fos expression in each region in the dams. Taken together, the present results suggest that FosB expression is co-involved with Fos in the neural activation during parturition and lactation in rats.

Animals↗
PubMed1998

Isolation and identification of a second diuretic hormone from Tenebrio molitor.

A diuretic hormone (DH) of unusual structure was isolated from extracts of heads of Tenebrio molitor. The hormone is a 47 amino acid peptide, Mr = 5,029.9, with the sequence AGALGESGASLSIVNSLDVLRNRLLLEIARKKAKEGANRNRQILLSL. This peptide increases cyclic AMP production in Malpighian tubules of T. molitor. We recently identified a smaller DH from T. molitor with 37 amino acids; these peptides have only 15 identical amino acids when aligned to maximize similarity to other members of the insect DH family. This family has sequence similarity to the corticotropin-releasing factor superfamily of vertebrate peptides.

Amino Acid Sequence↗
PubMed1998

Focused Ion Beam Interfaced with a 200 keV Transmission Electron Microscope for In Situ Micropatterning on Semiconductors.

: A focused ion beam (FIB) interface attached to a column of 200 keV transmission electron microscope (TEM) was developed for in situ micropatterning to semiconductors. TEM specimens of Si and GaAs, and those of a thin Ni2Si layer on a Si substrate were micromilled in the TEM during observation. A set of 6 x 6-µm squares and alphabet letters were patterned with a 25 keV Ga+-FIB of 0.2-µm beam diameter at room temperature. The effect of FIB irradiation on the structural evolution was observed simultaneously by a TV-rate video camera and sequentially by regular film. FIB micropatterning to semiconductor specimens caused amorphization and Ga injection. The excess Ga in the specimens precipitated as metastable solid gamma-phase for Si and as liquid phase for GaAs. Ni2Si/Si specimens lost silicide crystallinity after FIB patterning. Annealing of these bilayer specimens at 673K resulted in the precipitation of Ni-rich silicide.

Journal Article↗
PubMed1998

Molecular studies of bronchial asthma, sarcoidosis and angiotensin converting enzyme inhibitor-induced cough.

The role of genetic factors was reviewed with respect to the pathophysiology of bronchial asthma, sarcoidosis and cough induced by angiotensin converting enzyme (ACE) inhibitor administration. The so-called 'atopy gene' in 11q13 is not linked to atopy but is associated with serum IgE levels. The beta2-adrenergic receptor gene on 5q32-33 was found to have polymorphism by Ban I and to be related to beta2-receptor function; a defect of a 2.3 kb allele is related to lowered sensitivity to beta2-agonists. This defect is also related to higher prevalence on non-atopic bronchial asthma. The occurrence of amino acid mutation (Arg16 to Gly) of beta2-receptors was lower and Gln27 to Glu mutation is extremely rare in the Japanese population compared with Caucasians. There is polymorphism of ACE genotypes among normal subjects and patients with sarcoidosis, II, ID and DD. The genotype is a significant determinant of serum ACE activity and may determine the prognosis of sarcoid patients. Genotype II has a higher incidence of coughing induced by ACE inhibitors.

Alleles↗
PubMed1998

Secretion of GM-CSF by inflammatory cells in the lung of patients with sarcoidosis.

Several cytokines are involved in the pathophysiology of sarcoidosis. Granulocyte-macrophage colony-stimulating factor (GM-CSF) may be one of these cytokines because its mRNA is expressed by inflammatory cells obtained from the sarcoid lung. We thus asked two questions. Is GM-CSF secreted by bronchoalveolar lavage (BAL) cells? What type of cells express GM-CSF? GM-CSF secreted by the cultured BAL cells from 19 untreated sarcoid patients was measured by an enzyme-linked immunosorbent assay. The individual cells expressing GM-CSF mRNA were identified by in situ hybridization in seven patients. Spontaneous release of GM-CSF by BAL cells was demonstrated in one patient. When stimulated, BAL cells secreted GM-CSF in all subjects studied. In situ hybridization with digoxigenin-labelled GM-CSF cRNA probe revealed that the positive cells were round in shape and larger than lymphocytes, but smaller than large alveolar macrophages that are often irregular in shape. These results strongly indicated that small alveolar macrophages secrete GM-CSF in the sarcoid lesion. This phenomenon may contribute to the enhanced immunological activities observed in sarcoidosis.

Bronchoalveolar Lavage Fluid↗
PubMed1998

Symptomatic tonsillar ectopia.

OBJECTIVE: To determine if slight descent of the cerebellar tonsils (< 5 mm below the foramen magnum; tonsillar ectopia) may cause surgically treatable symptomatology. METHODS: A consecutive series of nine symptomatic patients with tonsillar ectopia seen between December 1990 and March 1993 are reported on. The same number of age and sex matched controls were selected at random from outpatients. Twelve asymptomatic subjects with tonsillar ectopia were found among 5000 people between January 1991 and March 1996. Diagnosis of tonsillar ectopia was based on midsagittal MRI. RESULTS: Patients presented mainly with chronic intractable occipital dull pain, vertigo, and dysequilibrium. In all patients MRI showed normal brain structure except for tonsillar ectopia (-2.9 (SD 0.8) mm), which has historically been thought to be of no clinical relevance. In the control group the tonsilar position was +2.1 (SD 2.8) mm (p<0.01). Neurotologically abnormal findings were detected with a monaural speech integration test (100%), eye tracking test (56%), optokinetic nystagmus test (89%), and visual suppression test (67%) which strongly suggested a CNS lesion. In accordance with the results of MRI and precise neurotological examination, posterior fossa decompression surgery was carried out, followed by improvement of preoperative symptoms and less severity of neurotological abnormalities in all patients. CONCLUSION: Tonsillar ectopia could cause neurological symptoms in small populations, which were surgically treatable. Neurotological assessment was necessary to verify the aetiological relation between tonsillar ectopia and various symptoms.

Adult↗
PubMed1998

Expression of RANTES by bronchoalveolar lavage cells in nonsmoking patients with interstitial lung diseases.

Emphasis has recently been placed on the roles of chemotactic cytokines called chemokines to explain the accumulation of inflammatory cells in the lung that may precede or accompany pulmonary fibrosis in interstitial lung diseases. We hypothesized that RANTES, a member of the C-C chemokines, is one such chemokine. Bronchoalveolar lavage was done in 20 patients with sarcoidosis, 10 patients with interstitial pneumonia associated with collagen vascular disease (CVD-IP), 10 patients with idiopathic pulmonary fibrosis (IPF), and eight healthy volunteers (HV), all of whom were never-smokers. We semiquantitated the spontaneous RANTES mRNA expression by a competitive reverse transcription-polymerase chain reaction (RT-PCR) technique, and measured the levels of RANTES protein by enzyme-linked immunosorbent assay. In all disease groups the expression of RANTES mRNA by bronchoalveolar lavage fluid (BALF) cells and the levels of RANTES protein in BALF were significantly increased compared with those in HV. Patients with sarcoidosis and CVD-IP had a significant positive correlation between the expression of RANTES mRNA by BALF cells and BALF lymphocytosis. The amounts of RANTES mRNA expressed by peripheral blood mononuclear cells and the levels of RANTES protein in serum did not differ among all study groups. Our study demonstrates the adaptability of a semiquantitative RT-PCR method for determining cytokine mRNA expression in vivo. Our results suggest that RANTES may be one of the chemokines that are involved in the mechanism for the accumulation of inflammatory cells in the lung of some distinct interstitial lung diseases.

Bronchoalveolar Lavage↗
PubMed1998

Elongation of the epiphyseal trabecular bone in transgenic mice carrying a klotho gene locus mutation that leads to a syndrome resembling aging.

Bone diseases such as osteoporosis and osteoarthritis are regarded as age-associated diseases, and occur in a significantly increasing number of patients, but the underlying mechanisms of these age-associated bone diseases are not yet clear. We have established a transgenic mouse line by an insertion mutation. These mice exhibit many features related to precocious aging. Homozygote mutant mice, which lack expression of the newly identified targeted gene,klotho (kl), exhibit atherosclerosis, emphysema, hypogonadism and calcification of soft tissues, and die within 3-4 months. We describe here the radiological and histological characteristics of the skeletal abnormalities in the bones of the mice with a mutation in the kl gene locus. In heterozygous mice (+/kl), the skeletal patterns and structures remain normal and most features are similar to those in the wild-type, whereas histological examinations of homozygous mice (kl/kl) show abnormal elongation of the trabecular bone(s) in the epiphyses of long bones. As with their long bones, on radiographic examination the mid parts of the vertebral bones of these mice show less radiopacity compared with the wild-type, again resembling human vertebrae of osteoporotic patients. The elongation of the trabecular bones results in high radiopacity on both ends of each of the vertebrae, and in the epiphyses of the long bones. Cancellous bone volume in the epiphyses of the homozygote mice is three times that of the wild-type mice. The kl/kl mice are smaller than the wild-type litter mates and hence the size of their long bones is less than that of the wild-type litter mates. These observations, and the osteopenia in the vertebrae and long bones in these mice, suggest the presence of abnormality in bone metabolism, the elongation of the trabecular bone apparently resulting from the relatively low levels of bone resorption. Therefore, thekl/kl mutant mice could serve as an interesting tool to study the effects of the lack of the product of the new gene,klotho, on bone metabolism.

Aging↗
PubMed1998

[Toremifene sensitized the effect of adriamycin on human breast cancer cell lines].

A experimental study was reported here to clarify the chemosensitizing effect of Toremifene (Tor) on human breast cancer cell lines. MCF7, estrogen dependent adriamycin (ADM) resistant cell, and MDA-MB231, estrogen independent cell, were preincubated for 8 hours with Tor 0, 4 or 10 microM, then with ADM 0-10 micrograms/ml for one hour. After that, cells were cultured for 24 hours, and their cell cycle and growth were analyzed with flow-cytometry and MTT assay, respectively. Furthermore, the ADM concentrations of these cells were measured by high-performance liquid chromatographic assay (HPLC). Although flowcytometric analysis showed the enhancement of Gz block only in MCF7 at the ADM concentration with 5 micrograms/ml, the sensitizing effect was revealed by MTT assay, and the elevation of ADM concentration was found in HPLC assay in both cells. The chemosensitizing effect of Toremifene was observed in estrogen dependent and independent cell lines.

Antibiotics, Antineoplastic↗
PubMed1998

Giant cell fibroblastoma associated with dermatofibrosarcoma protuberans: a case report.

A case of congenital giant cell fibroblastoma (GCF) associated with dermatofibrosarcoma protuberans (DFSP) in a 1.5-year-old girl is reported. The GCF component was characterized by a mixed proliferation of fibroblastic cells and multinucleated giant cells and sinusoid-like spaces. The DFSP component, which was spatially distinct from the GCF region, was composed of short spindle-shaped cells arranged in a storiform pattern. Mitotic figures were frequently identified in the DFSP area but not in the GCF region. Immunohistochemically, tumor cells in both components were positive for CD34. The Ki-67 labeling index of the DFSP area (4.9%) was markedly higher than that of the GCF (0.5%). Ultrastructurally, spindle-shaped tumor cells in both components, as well as giant cells, were fibroblastic cells that frequently exhibited multilobulated nuclei. This case illustrates the close histogenetic relationship between GCF and DFSP, although the degree of proliferative activity is much higher in the DFSP area.

Dermatofibrosarcoma↗