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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 145 records · Page 8Linked to original sources
PubMed2000

[Cervical pyogenic spondylodiscitis: 4 cases report and a review of the literature].

We report 4 cases of cervical spondylodiscitis presenting neurological and/or neuroradiological abnormalities. Such a lesion is rare in the cervical spine of adults, but should be suspected when the patient has radiculopathy and/or myelopathy associated with inflammatory signs. We discussed the clinical characteristics and the procedures of the diagnosis and treatment of cervical spondylodiscitis. Early and definitive diagnosis can be achieved by cervical X-ray, MR imaging and biopsy. It is very important to evaluate the pyogen for the lesion by needle biopsy. When the patient has the compression of the spinal cord and/or nerve roots and the neurological findings of radiculopathy and/or myelopathy, surgical exploration and decompression of the spinal cord and/or nerve roots should be carried out as soon as possible. Anterior debridement and fusion should be performed using the effective antibiotics. We were able to achieve good prognosis by treatment following this procedure of diagnosis in the four cases of cervical spondylodiscitis mentioned.

Adult↗
PubMed2000

[Syndrome of inappropriate secretion of antidiuretic hormone in a patient with myeloid antigen positive acute lymphoblastic leukemia after systemic chemotherapy including vincristine].

We report a case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after the patient had received several anti-cancer drugs, including vincristine (VCR), in a patient with myeloid antigen positive acute lymphoblastic leukemia (My(+)-ALL). A 53-year-old woman presented at the hospital complaining of high-grade fever and general lassitude. Further examination revealed that she had My(+)-ALL. On admission, she was treated with anti-cancer drugs, including VCR. On day 24, after the first administration of VCR, a conscious disturbance suddenly occurred and she was diagnosed with SIADH. A plain head CT scan showed a low density lesion through the gray matter to the white matter in the bilateral occipital lobe, as well as diffuse swelling of the cerebrum. This was not seen on the follow up CT scan, and we concluded that it had been a transient abnormal finding due to SIADH. She achieved complete remission after induction chemotherapy and 3 added courses of consolidation chemotherapy. VCR was also administered 4 times in the second consolidation chemotherapy, but hyponatremia did not occur. This case suggests that a head CT scan is a useful procedure for the diagnosis and monitoring of SIADH, and that VCR may still be used in a patient who has suffered from VCR-induced SIADH.

Antigens, Differentiation, Myelomonocytic↗
PubMed2000

Accumulation of macrophages with dendritic cell characteristics in the pulmonary response to Listeria.

Pulmonary immunity reflects a balance between proinflammatory and immunosuppressive factors in the lung. To determine the immune activities of exudate macrophages in the pulmonary immune response, Lewis rats were injected intratracheally with heat-killed Listeria (HKL), labeled ex vivo with the lipophilic dye PKH-26. At 24 h, macrophages from bronchoalveolar lavage fluid were purified on the basis of their surface membrane expression of RMA, a macrophage-specific antigen, which is brightly expressed by resident alveolar macrophages but dimly expressed by monocytes. Pulmonary macrophages were analyzed for uptake of PKH-26-HKL, and RMA(bright/dim) macrophages sorted by FACS were compared for cytokine expression, nitric oxide (NO) release, and APC activities. RMA(bright) macrophages were OX-62(-), B7(-), and factor XIIIa(-); they were the dominant mediators of phagocytosis when low doses of HKL were administered intratracheally but did not support the proliferation of T lymphocytes. RMA(dim) exudate macrophages were OX-62(+), B7(+), and factor XIIIa(+). They expressed more IL-1 and TNF, but less nitric oxide, than did RMA(bright) macrophages; they were excellent APCs for T cell responses. We conclude that a subset of RMA(dim) exudate macrophages shows phenotypic and functional evidence of dendritic cell differentiation.

Animals↗
PubMed2000

Rupture of infected pseudoaneurysms in patients with implantable ports for intra-arterial infusion chemotherapy.

Intra-arterial hepatic chemotherapy via implantable reservoirs is being used increasingly. In our department, five patients have undergone emergency surgery since 1991 because of rupture of an infected pseudo-aneurysm at the site of entry of the catheter. Surgical procedures included removal of the catheter and the reservoir, and closure of the affected artery with or without reconstruction. Of these patients, three (60%) died from uncontrollable sepsis. The poor prognosis emphasizes the need, in patients with carcinoma, for strict aseptic technique and hemostasis at the time of catheter placement, and for careful device maintenance.

Adult↗
PubMed2000

[Sjögren's syndrome with malignant lymphoma, interstitial pneumonia, and pulmonary hypertension].

A 62-year-old woman was admitted to our hospital for further examination of cough and dyspnea on exertion. She had suffered xerostomia and xerophthalmia for 7 years. Physical examinations showed purpura on the lower extremities, Raynaud's phenomenon, and swelling of the parotid glands. Laboratory data disclosed thrombocytopenia, hypergammaglobulinemia, and high titers of anti-nuclear antibody, anti SS-A, and anti SS-B antibodies. Sicca symptoms, a positive Schirmer's tear test, and laboratory findings together yielded a diagnosis of Sjögren's syndrome. Chest X-P and computed tomographic films demonstrated diffuse reticulonodular shadows and multiple nodules in the left lower lung. Echocardiography and right cardiac catheterization revealed enlargement of the right ventricle, tricuspid regurgitation, and elevated pulmonary arterial pressure. Histologic findings from an open-lung biopsy specimen revealed accumulation of inflammatory cells and fibrosis around broncho-vascular bundles, and diffuse large cell lymphoma. Despite a favorable response to chemotherapy, the patient died of right ventricular failure.

Female↗
PubMed2000

[Measles pneumonia presenting with multiple nodular opacities on chest radiographs].

A 22-year-old woman presented with fever, cough, and maculopapular erythematous rash on hands and feet. These symptoms developed 14 days after the onset of natural measles in the patient's daughter. Chest radiographs obtained on the first examination showed multiple nodular opacities and infiltrates in the left and right lung fields. Serological examinations disclosed elevated levels of the specific IgM antibody and a remarkably elevated hemagglutination inhibition (HI) titer, indicating a recent measles infection. The patient's symptoms, skin eruptions, and abnormal chest radiograph findings disappeared after several days. However, chest computed tomographic scans taken 8 months after the initial examination revealed small, residual nodular opacities. Other than the fact that the patient had received attenuated measles virus vaccine, these findings were typical of the clinical course for atypical pneumonia. We concluded that in the differential diagnosis of multiple nodular opacities on chest radiographs, adequate attention should be given to pulmonary involvement of measles infection.

Adult↗
PubMed1999

Deletion of the carboxyl-terminal exons of K-sam/FGFR2 by short homology-mediated recombination, generating preferential expression of specific messenger RNAs.

The K-sam gene was first identified as an amplified gene from human gastric cancer cell line KATOIII, and its product is identical to fibroblast growth factor receptor 2. The K-sam gene is located on human chromosome 10q26 and is preferentially amplified in the poorly differentiated types, especially in the scirrhous type, of gastric cancers. During the course of studies on the structural characterization of the amplification units, we found that the carboxyl-terminal exons of K-sam were deleted in three of four of the scirrhous type of gastric cancer cell lines. These deletions generate preferential expression of mRNAs encoding K-sam proteins lacking the carboxyl-terminal region containing the tyrosine residues at positions 780, 784, and 813. The carboxyl-terminal region has been reported to have a sequence required for the inhibition of NIH3T3 transformation, indicating that cells with amplification of the truncated K-sam gene have a growth advantage during the carcinogenic process for the scirrhous type of gastric cancers. This is the first report showing the deletion of the carboxyl-terminal exons of the receptor-type of the protein tyrosine kinase gene. Sequence analysis of the DNA sequences surrounding the deletion junctions shows the presence of unique sequences and indicates the involvement of short homology-mediated recombination in the generation of these deletions.

3T3 Cells↗
PubMed1999

Ezrin, a membrane-cytoskeletal linking protein, is involved in the process of invasion of endometrial cancer cells.

In order to study ezrin function in tumor growth and invasion, we used two cell lines of human endometrial cancers. Ishikawa, the low-metastatic endometrial cancer cell line, and its subclone (mEIIL) with high-metastatic activity and higher ezrin expression were treated with a ezrin antisense phosphorothioate oligonucleotides (ePONs) pulse four times before the in vitro growth assay and Matrigel invasion assay. ePONs significantly suppressed the number of both cells that penetrated through Matrigel membrane (inhibition rate; 40.1 +/- 7.5% (Ishikawa), 42.7 +/- 2.4% (mEIIL), mean +/- SD, n = 6, P < 0.05, Student's t-test), whereas they showed no effect on cell proliferation. Ezrin expression at the protein level was inhibited by ePONs. These data suggest that ezrin expression is required for invasion. The association of high ezrin expression in mEIIL and its higher ability to migrate through Matrigel may at least in part indicate functional significance of ezrin in endometrial cancer metastasis.

Adenocarcinoma↗
PubMed1999

Novel exons located more than 200 kb downstream of the previously described 3' exon of the K-sam gene for generating activated forms of KGF receptor.

The K-sam gene was first identified as an amplified gene in the poorly differentiated types, especially in the scirrhous type, of gastric cancers. We have recently found and reported that the carboxyl-terminal exons of K-sam are frequently deleted in the scirrhous type of gastric cancer. The deletion generates preferential expression of at least six novel K-sam-II mRNAs: K-sam-IIH1, -IIH2 and -IIH3/O4, and K-sam-IIO1, -IIO2, and -IIO3, which encode novel proteins lacking the transformation-inhibitory sequence or activated K-sam proteins. In this study, we investigated expression of the previously described K-sam-IIC1 and -IIC3 mRNAs and the novel six K-sam-II mRNAs in 14 gastric cancer cell lines, 7 breast cancer cell lines, and 20 human normal tissues. All the six novel K-sam-II mRNAs were expressed preferentially in the cell lines derived from the scirrhous type of gastric cancers but not in the 7 breast cancer cell lines and the 20 human normal tissues. We further determined the positional relationship of four exons of H1, O1, O2, and O3 out of the six exons of H1, H2, H3/O4, O1, O2, and O3, and found that these four novel K-sam exons were located more than 200 kb downstream of the previously described carboxyl-terminal exon of the K-sam gene. Expression of K-sam-IIH1, -IIO1, and -IIO2 mRNAs encoding activated K-sam products in the scirrhous type of gastric cancer cell lines HSC39, OCUM2M, HSC59, and HSC60 was not due to the deletion of the C1 exon of K-sam.

Amino Acid Sequence↗
PubMed1999

Adenovirus-mediated transfer of HST-1/FGF-4 gene protects mice from lethal irradiation.

Intraperitoneal injection of a replication-deficient adenovirus containing the HST-1 (FGF-4) gene (Adex1HST-1) increased peripheral platelet counts in mice, and also effectively prevented experimentally induced thrombocytopenia. Here, we report the therapeutic potential of Adex1HST-1 on severely injured mice after exposure to otherwise lethal irradiation. Eighteen out of 20 mice that received Adex1HST-1 prior to gamma-irradiation (9 Gy) survived, while all the 20 mice with prior administration of control adenoviruses died after irradiation (P<0.0001). Hematological and histopathological analyses revealed that Adex1HST-1 acts as a potent protector against lethal irradiation, which causes injury of intestinal tract as well as myelosuppression in the bone marrow and spleen. These data demonstrate that the protective effects of administration of Adex1HST-1 against irradiation are superior to any other protective effects of cytokines against a lethal dose of irradiation, and that the pre-administration of Adex1HST-1 may be useful for lessening the side effects of currently used chemo- and radio-therapy against cancer.

Adenoviruses, Human↗
PubMed1999

Estrogen receptor beta and progesterone receptor mRNA in the intergeniculate leaflet of the female rat.

The present study was undertaken to explore the possibility that the integration of hormonal cues in the regulation of neuroendocrine mechanisms may occur outside of the hypothalamus at the level of the lateral geniculate body. In situ hybridization for mRNA encoding estrogen receptor beta and progesterone receptor was carried out on sections containing the lateral geniculate body using [35S]-labeled antisense riboprobes. Labeled cells were present in different limbic and hypothalamic sites as described previously. Populations of cells distributed homogeneously in the ventral lateral geniculate nucleus and intergeniculate leaflet were also found to express mRNA for estrogen receptor beta and progesterone receptor. The dorsal lateral geniculate nucleus lacked specific labeling for either type of gonadal steroid hormone receptor mRNA. The present observation together with the recent demonstration of a direct pathway between the intergeniculate leaflet and hypothalamic neuroendocrine cells indicate that integration of hormonal and photic stimuli in the central regulation of endocrine mechanisms occurs outside of the hypothalamus in the lateral geniculate body.

Animals↗
PubMed1999

Structural characterization of chemically derivatized oligosaccharides by nanoflow electrospray ionization mass spectrometry.

Oligosaccharides released from several glycoproteins were derivatized with either 4-aminobenzoic acid 2-(diethylamino)ethyl ester (ABDEAE) (Yoshino, K.; et al. Anal. Chem. 1995, 67, 4028-4031) or 2-aminopyridine. The resulting derivatives were analyzed on a nanoflow electrospray ionization (ESI) quadrupole-inlet time-of-flight mass spectrometer using the low-energy collision-induced dissociation technique. In the MS/MS spectra, the oxonium (b or internal series) and y series ions, which are derived from the multiply charged precursor ions, were predominant and were used for the structural readout. Some oxonium ions that were observed in the low-mass region, but that were not found in the PSD analyses (Mo, W.; et al. Anal. Chem. 1998, 70, 4520-4526), rendered a more detailed structural insight. The oxonium ions at m/z 512.2, which are derived from the fucosylated oligosaccharides of immunoglobulin Y and thyroglobulin, were observed, suggesting that fucosylation had occurred proximal to the outer nonreducing terminus. In addition, the data herein show that structural elucidation can be routinely achieved at a low sample concentration. For the case of ABDEAE derivatives, this can be achieved at the 50 fmol/microL level and with the actual sample consumption at the attomole level using nanoflow ESI MS/MS.

Aminopyridines↗
PubMed1999

Lateromedial and dorsoplantar borders among supplying areas of the nerves innervating the intrinsic muscles of the foot.

The branching patterns of nerves supplying the intrinsic muscles of the foot were analyzed as a basis to confirm the muscle layer structure. Thirty-eight feet of 20 Japanese cadavers were examined in detail in this study. The first dorsal interosseus was innervated by a branch from the deep peroneal nerve as well as a branch of the lateral plantar nerve in 92.1%, the second dorsal interosseus in 10. 5% and the third dorsal interosseus in 2.6%. In three specimens, branches from the deep peroneal nerve innervated the oblique head of the adductor hallucis or the lateral head the flexor hallucis brevis. In addition, branches from the medial and lateral plantar nerves and the deep peroneal nerve formed communication loops in three specimens. The first dorsal interosseus, the oblique head of the adductor hallucis and the lateral head of the flexor hallucis and their innervating nerve branches are closely related within the first intermetatarsal space. Since the tibial part of the first interosseus muscle primordium is occupied in the space during development, the variations of innervation patterns and formation of the communicating nerve loops may be explained by various combinations of the part and the other muscle primordia.

Adult↗
PubMed1999

Neuronal expression of a Caenorhabditis elegans elav-like gene and the effect of its ectopic expression.

We examined the expression of a Caenorhabditis elegans (C. elegans) elav-like gene, which we designated elr-1. The elr-1 gene encodes a predicted 456-amino-acid protein containing three putative RNA-binding domains and belongs to the ELAV family, which is functionally involved in neuronal differentiation. Northern blot analysis suggested that the levels of elr-1 mRNA are regulated developmentally. A elr-1::gfp reporter gene under the control of the elr-1 promoter was expressed specifically in the ring ganglia near the nerve ring, the ventral nerve cord (VNC), and the pre-anal and lumbar ganglia. In the VNC, GFP-positive cells were shown to be acetylcholine-producing motor neurons which increased in number as development proceeded, suggesting that elr-1 is expressed in mature neurons. Ectopic expression of ELR-1 protein at the L4 larval and adult stages, but not earlier stages, caused irreversible death, accompanied by uncoordinated movement (Unc), clear (Clr), and egg-laying defective (Egl) phenotypes, which are often observed in mutants with neuronal defects. These results suggest that ELR-1 may have important functions in specific mature neurons in C. elegans.

Amino Acid Sequence↗
PubMed1999

Ferric alpha-hydroxyheme bound to heme oxygenase can be converted to verdoheme by dioxygen in the absence of added reducing equivalents.

Whether or not reducing equivalents are indispensable for the conversion of ferric alpha-hydroxyheme bound to heme oxygenase-1 to verdoheme remains controversial (Matera, K. M., Takahashi, S., Fujii, H., Zhou, H., Ishikawa, K., Yoshimura, T., Rousseau, D. L., Yoshida, T., and Ikeda-Saito, M. (1996) J. Biol. Chem. 271, 6618-6624; Liu, Y., Moënne-Loccoz, P., Loehr, T. M., and Ortiz de Montellano, P. R. (1997) J. Biol. Chem. 272, 6906-6917). To resolve this controversy, we have prepared a ferric alpha-hydroxyheme-heme oxygenase-1 complex and titrated the complex with O2 under strictly anaerobic conditions. The formation of verdoheme was monitored by optical and electron spin resonance spectroscopies. Electron spin resonance spectra of the complex showed that alpha-hydroxyheme exists as a mixture of resonance structures composed of the iron(III) porphyrin and the iron(II) porphyrin pi neutral radical. Upon addition of CO the latter species becomes dominant. The results obtained from these titration experiments indicate that alpha-hydroxyheme can be converted to verdoheme by an approximately equimolar amount of O2 without any requirement for exogenous electrons. The verdoheme formed from alpha-hydroxyheme was shown to be in the ferrous oxidation state by the addition of CO or potassium ferricyanide to the resultant verdoheme-heme oxygenase-1 complex.

Electron Spin Resonance Spectroscopy↗