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Biomedical subjects

Y Mochizuki

Publications and source records attributed to Y Mochizuki.

At least 55 records · Page 3Linked to original sources
PubMed2001

[A case of breast cancer with bone marrow and liver metastases responding completely to low-dose weekly paclitaxel combined with toremifene].

A 36-year-old woman was admitted to our hospital because of general malaise in October 1999. She was diagnosed with bilateral breast cancer with bone marrow and liver metastases. Low-dose weekly paclitaxel (60 mg/body/week) combined with toremifene (120 mg/day) was started in December 1999. Myelofunction was recovered after 2 weeks of chemotherapy (CT), and the primary tumors and cervical/axillary lymphadenopathy disappeared after 4 weeks of CT. Bone marrow and liver metastases was no longer detected after 16 weeks of CT, and the case was evaluated as a complete response (CR). The same therapy has been performed for eight months and no evidence of recurrence has been observed.

Adult↗
PubMed2001

Vascular endothelial growth factor C promotes human gastric carcinoma lymph node metastasis in mice.

Vascular endothelial growth factor (VEGF)-C, one of several members of the VEGF family, is a relatively specific lymphangiogenic growth factor. VEGF receptor (VEGFR)-3 (or Flt4) is a VEGF-C receptor with expression restricted to lymphatic endothelial cells. Since the mechanisms by which carcinoma cells metastasize to lymph nodes remain unclear, we constructed a VEGF-C transfectant (AZ-VEGF-C) from the AZ521 human gastric carcinoma cell line, which ordinarily shows little nodal metastatic potential and little VEGF-C expression. We orthotopically implanted transfected tumor cells into the stomachs of nude mice. The number of mice developing lymph node metastases and the number of lymph node metastases per mouse with nodal metastases were higher than with implants of mock-transfected control cells. Specifically, percentages of mice with lymph node metastases were 95.5% (21/22) for AZ-VEGF-C and 29.4% (5/17) for controls (P<0.01), while mean numbers of involved lymph nodes were 3.76 for AZ-VEGF-C and 1.00 for controls (P<0.01). No difference was found between AZ-VEGF-C and controls regarding cell growth and chemotactic responses in vitro, or in volumes of tumors arising from implanted cells. When we performed immunohistochemical staining for VEGFR-3 in these tumors to investigate lymphangiogenesis by VEGF-C, the number of vessels stained for VEGFR-3 in tumors and surrounding tissues was higher for AZ-VEGF-C than for controls. VEGFR-3-positive vessels occupied 14.9/1000 of microscopically examined areas for AZ-VEGF-C, but only 1.30/1000 for controls (P<0.001). Our results suggest that VEGF-C is a specific lymphangiogenic growth factor with an important role in lymph node metastasis.

Animals↗
PubMed2001

[A case of bilateral synchronous renal cell carcinoma treated with left partial nephrectomy and laparoscopic right nephrectomy].

We describe a case of bilateral synchronous renal cell carcinoma. A 70-year-old female was admitted to our department because of further examination for bilateral renal masses. Computed tomographic scanning and ultrasound examinations revealed bilateral solid enhanced renal masses, and bilateral renal cell carcinomas were suspected. First, partial left nephrectomy was performed. On the 21th day after the first operation, we confirmed the recovery of the left kidney, and performed right nephrectomy laparoscopically. The histopathological diagnosis revealed bilateral renal cell carcinomas. The patient is alive with no metastatic lesions and no recurrence at 16 months after the operations.

Aged↗
PubMed2001

Cutaneous polyarteritis nodosa: therapy and clinical course in four cases.

Cutaneous polyarteritis nodosa (PN) has a benign and chronic course; relapses are frequently associated with steroid dependence. We have observed four cases of cutaneous PN in the past 15 years and followed up two of the four cases long-term for 13 and 10 years after diagnosis. There has been a marked contrast in the clinical courses of these two cases: one case has shown a complete remission for 12.5 years without treatment during the most recent 11 years; the other case had four relapses and has never experienced cessation of treatment. The only difference between the two cases was careful therapy with adequate prednisolone in the long-term remission case. The other two cases clinically showed erythema nodosum-like features, and they had antecedent sore throats and embedded chronic tonsillitis; one was associated with presumed streptococcal infection. These two cases may simply be an accelerated process of post-streptococcal erythema nodosum rather than typical cutaneous PN. We performed tonsillectomies as adjuvant therapy in these two cases. No relapse of the disease has been observed in these two cases, and the tonsillectomy allowed us to taper the dose of steroids, resulting in discontinuation of the treatment in one of the two cases. The duration of the remission as well as the adjuvant therapy was variable in each of our cutaneous PN cases. Tonsillectomy can be recommended as an adjuvant to steroids for PN cases with chronic tonsillitis and/or streptococcal infection.

Adolescent↗
PubMed2001

Repair of articular cartilage on the surface of heat-treated bone by transplantation of cultured chondrocytes.

The present study addresses clinical problems associated with the degeneration of articular cartilage, which occurs when heat-treated bone with articular cartilage is used for re-implantation after resection of malignant bone tumors adjacent to the joints. We therefore evaluated the effect of transplantation of chondrocytes embedded in collagen gel on the surface of heat-treated bone. A cylindrical complex of bone and articular cartilage 6 mm in diameter was resected from rabbits' patellar grooves and treated in saline at 60 degrees C for 30 min. In Group A, articular cartilage was resected from the complex and the remaining bone was returned to the patellar groove. Then, autologous chondrocytes cultured in collagen gel were transplanted and covered with periosteum. As controls, the original complex of heat-treated bone and articular cartilage (Group B) and heat-treated bone directly covered with periosteum (Group C) was returned to the patellar groove. In Group A, histological study showed that round cells were mainly observed and the matrix was well stained with Safranin O in the repair tissue after 24 weeks. The repair tissue was as thick as the adjacent normal cartilage. Immunohistological study detected type-II collagen and chondroitin-6-sulphate (3B3+) in the matrix of the repair tissue, but not type-I collagen. The repair tissue was consequently cartilaginous in Group A. The repair tissue was not cartilaginous or was degenerative in the control groups. We believe that this modality of heat-treated joints will contribute to limb salvage reconstruction after resection of malignant bone tumors adjacent to the joints.

Animals↗
PubMed2000

Complete genome structure of the nitrogen-fixing symbiotic bacterium Mesorhizobium loti.

The complete nucleotide sequence of the genome of a symbiotic bacterium Mesorhizobium loti strain MAFF303099 was determined. The genome of M. loti consisted of a single chromosome (7,036,071 bp) and two plasmids, designated as pMLa (351,911 bp) and pMLb (208, 315 bp). The chromosome comprises 6752 potential protein-coding genes, two sets of rRNA genes and 50 tRNA genes representing 47 tRNA species. Fifty-four percent of the potential protein genes showed sequence similarity to genes of known function, 21% to hypothetical genes, and the remaining 25% had no apparent similarity to reported genes. A 611-kb DNA segment, a highly probable candidate of a symbiotic island, was identified, and 30 genes for nitrogen fixation and 24 genes for nodulation were assigned in this region. Codon usage analysis suggested that the symbiotic island as well as the plasmids originated and were transmitted from other genetic systems. The genomes of two plasmids, pMLa and pMLb, contained 320 and 209 potential protein-coding genes, respectively, for a variety of biological functions. These include genes for the ABC-transporter system, phosphate assimilation, two-component system, DNA replication and conjugation, but only one gene for nodulation was identified.

ATP-Binding Cassette Transporters↗
PubMed2000

Identification and characterization of a novel inositol polyphosphate 5-phosphatase.

We have identified a cDNA encoding a novel inositol polyphosphate 5-phosphatase. It contains two highly conserved catalytic motifs for 5-phosphatase, has a molecular mass of 51 kDa, and is ubiquitously expressed and especially abundant in skeletal muscle, heart, and kidney. We designated this 5-phosphatase as SKIP (Skeletal muscle and Kidney enriched Inositol Phosphatase). SKIP is a simple 5-phosphatase with no other motifs. Baculovirus-expressed recombinant SKIP protein exhibited 5-phosphatase activities toward inositol 1,4,5-trisphosphate, inositol 1,3,4,5-tetrakisphosphate, phosphatidylinositol (PtdIns) 4,5-bisphosphate, and PtdIns 3,4, 5-trisphosphate but has 6-fold more substrate specificity for PtdIns 4,5-bisphosphate (K(m) = 180 microM) than for inositol 1,4, 5-trisphosphate (K(m) = 1.15 mM). The ectopic expression of SKIP protein in COS-7 cells and immunostaining of neuroblastoma N1E-115 cells revealed that SKIP is expressed in cytosol and that loss of actin stress fibers occurs where the SKIP protein is concentrated. These results imply that SKIP plays a negative role in regulating the actin cytoskeleton through hydrolyzing PtdIns 4,5-bisphosphate.

Amino Acid Sequence↗
PubMed2000

CD8-depleted donor leukocyte transfusions for cytomegalovirus antigenemia in patient with acute lymphoblastic leukemia treated with allogeneic CD34(+) cell transplantation.

A 24-year-old man with acute lymphoblastic leukemia received an allogeneic CD34(+) cell transplant from an HLA-mismatched sibling because of refractory disease. The CD34(+) cells were enriched by the immunomagnetic method. One month after the transplant his situation became complicated due to cytomegalovirus (CMV) antigenemia, which was resistant to treatment with ganciclovir. He was treated with CD8(+) cell-depleted donor lymphocyte transfusions (CD8-depleted DLT). After CD8-depleted DLT, the CMV antigenemia disappeared completely. This case report suggested that CD8-depleted DLT was an effective therapy for CMV antigenemia after allogeneic CD34(+) cell transplantation.

Adult↗
PubMed2000

L-histidine but not D-histidine attenuates brain edema following cryogenic injury in rats.

Oxygen free radicals have been implicated in the genesis of traumatic brain injury and brain edema (BE). Recent studies have suggested that hydroxyl radical can initiate lipid peroxidation, thus producing lipid-free radicals that may become important sources of singlet oxygen. L-histidine, a singlet oxygen scavenger, potentially can be used to treat BE. In this study we investigated the effects of L-histidine and D-histidine on BE following cryogenic injury in rats. Male Wistar rats were anaesthetized with chloral hydrate. Vasogenic BE was produced by a cortical freezing lesion. Generation of singlet oxygen from photoactivation of rose bengal was studied by electron spin resonance (ESR). Animals were separated into four groups: sham rats (n = 5), saline-treated rats (n = 10), L-histidine treated rats (n = 6) and D-histidine treated rats (n = 7). Each agent (100 mg/kg) was administered intravenously at 30 minutes before lesion production. Animals were sacrificed at 24 hours after lesion production and the brain water content was determined by the dry-wet weight method. L-histidine had no effect on rectal and brain temperature. Election Spin Resonance studies demonstrated that L-histidine is a singlet oxygen scavenger. L-histidine but not D-histidine significantly attenuated BE following cryogenic injury (p < 0.05). In conclusion, L-histidine is useful in the treatment of traumatic BE.

Animals↗
PubMed2000

Protective effect of a novel vitamin E derivative on experimental traumatic brain edema in rats--preliminary study.

Oxygen free radicals have been proposed to be one of the major mechanisms of secondary brain damage in traumatic brain injury. Protective effect by vitamin E against oxidative damage has attracted much attention. Recent studies have demonstrated a novel vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), has excellent water-solubility and antioxidant activity. The purpose of this study was to investigate protective effects of TMG on experimental traumatic brain edema (BE). Male Wistar rats were anaesthetized with chloral hydrate. Traumatic BE was produced by a cortical freezing lesion. Animals were separated into three groups: saline-treated rats (n = 4), TMG-treated (4 mg/kg) rats (n = 7) and TMG-treated (40 mg/kg) rats (n = 8). Saline or TMG was administered intravenously before lesion production. Animals were sacrificed at 6 hours after lesion production and the brain water content was determined by the dry-wet weight method. Half-life of TMG after intravenous administration of TMG was also investigated. The half life of TMG was approximately 5 minutes. TMG (40 mg/kg) significantly attenuated BE following cryogenic brain injury (p < 0.01). In conclusion, this preliminary study has demonstrated that a novel vitamin E derivative might be promising in the treatment of traumatic BE.

Animals↗
PubMed2000

NO-mediated MaxiK(Ca) channel activation produces relaxation of guinea pig aorta independently of voltage-dependent L-type Ca(2+) channels.

The role of L-type Ca(2+) channels in the relaxation to nitric oxide (NO)-mediated MaxiK(Ca) channel activation was examined in guinea pig aorta. Acetylcholine (ACh) produced an endothelium-dependent relaxation of guinea pig aorta precontracted with noradrenaline (NA), which was abolished by an NO synthase inhibitor, N(G)-nitro-L-arginine (L-NNA). Both endothelium-dependent relaxation by ACh and endothelium-independent relaxation by an NO donor, (+/-)-(E)-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexeneamide (NOR3), were strongly suppressed by a soluble guanylate cyclase (sGC) inhibitor, 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ), suggesting that increased intracellular cGMP plays the key role in both responses. ACh- and NOR3-induced relaxations were significantly suppressed by iberiotoxin (IbTX), a selective blocker of MaxiK(Ca) channels. ACh- and NOR3-induced relaxations were greatly attenuated when arteries were precontracted with high KCl instead of NA, supporting the idea that K(+) channel activation mediates the relaxant responses. (6) NOR3-induced relaxations were not affected by a L-type Ca(2+) channel blocker, diltiazem. Furthermore, endothelium-independent relaxation by a K(ATP) channel opener, (+)-7,8-dihydro-6, 6-dimethyl-7-hydroxy-8-(2-oxo-1-piperidinyl)-6H-pyrano[2,3-f] benz-2,1, 3-oxadiazole (NIP-121) was not affected by diltiazem and nicardipine. These findings suggest that blockade of L-type Ca(2+) channels is not a major mechanism responsible for the vascular relaxation due to NO-mediated MaxiK(Ca) channel activation in guinea pig aorta.

Acetylcholine↗
PubMed2000

Paper is a compatible bed for rat hepatocytes.

To develop an effective hybrid bioartificial liver (BAL) device, the material of the scaffold is very important to support hepatocytes that have both growth ability and hepatic differentiated functions. In this study we used paper (Kimwipe, Kimberly-Clark Corp., Roswell, GA, U.S.A.) as a scaffold. Primary hepatocytes isolated from a normal adult rat liver could proliferate on the paper. The secretion of albumin into culture medium by the cells on the paper increased with time in culture and, compared to the cells on dishes, the amount of 48 h albumin secretion at Day 10 was two times larger. Perpendicular sections of hepatocytes on the paper revealed that the cells fell into cavities made by intersecting fibers, piled up, and formed three to four layers. The piled-up cells changed their shape from flat to cuboidal and enlarged their cytoplasm, which was rich in organelles such as mitochondria and peroxisomes with a nucleoid. In addition, they formed bile canalicular structures between the cells. Their morphological appearance was similar to in vivo hepatocytes. Paper (Kimwipe) may be a good candidate as a scaffold to make a BAL device.

Albumins↗
PubMed2000

Application of positron emission tomography imaging to cancer screening.

Whole-body positron emission tomography (PET) with(18)F-fluorodeoxyglucose (FDG) is a diagnostic modality that can noninvasively survey the entire body and sensitively detect various cancers. In this study, we examined the potential application of whole-body PET for cancer screening in asymptomatic individuals. PET was performed in conjunction with conventional examinations including physical examination, laboratory study, ultrasonography and chest computed tomography. Between September 1994 and March 1999, 3165 asymptomatic individuals participated in 5575 screening sessions (2017 men and 1148 women; mean +/- SD age, 52.2+/-10.4 years). Follow-up periods were no less than 10 months. PET results were compared with the screening outcomes. Within 1 year after screening, malignant tumours were discovered in 67 of the 3165 participants (2.1%). PET findings were true-positive in 36 of the 67 cancers (54%). Most of the 36 patients underwent potentially curative surgery; thus a wide variety of cancers were detected by PET at potentially curable stages. However, PET findings were false-negative in 31 of the 67 patients (46%). 14 of these 31 (45%) were of urological origin. FDG PET imaging has the potential to detect a wide variety of cancers at potentially curable stages. However, PET imaging is not suited to screening test of general population because PET examination involves substantial cost.

Adult↗
PubMed2000

Regulation of dihydropyrimidine dehydrogenase and pyrimidine nucleoside phosphorylase activities by growth factors and subsequent effects on 5-fluorouracil sensitivity in tumor cells.

Dihydropyrimidine dehydrogenase (DPD) and pyrimidine nucleoside phosphorylase (PyNPase) are the first and rate-limiting enzymes that regulate 5-fluorouracil (5-FU) metabolism, and tumoral DPD activity appears to be a promising predictor of 5-FU sensitivity. However, the regulatory mechanisms determining these enzyme activities have not been fully understood. We investigated the biological effects of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha on cell growth and tumoral DPD and PyNPase activities, and the subsequent effects on 5-FU sensitivity in uterine cervical carcinoma SKG-IIIb cells. The treatment of tumor cells with EGF or TGF-alpha resulted in a concentration-dependent increase in tumor cell growth and PyNPase activity, whereas tumoral DPD activity was inhibited. Their stimulatory effects on tumor cell growth correlated well with PyNPase activity, but were inversely related to DPD activity (P < 0.01). 5-FU sensitivity of tumor cells increased in the presence of EGF or TGF-alpha. These growth factors were shown to stimulate the first, rate-limiting enzyme activity in 5-FU anabolism and to inhibit that in 5-FU catabolism, leading to enhancement of the antiproliferative action of 5-FU at achievable therapeutic levels. The tumor environmental factors, EGF and TGF-alpha, may act as intrinsic regulators of DPD and PyNPase activities that affect the 5-FU sensitivity of individual tumors.

Antimetabolites, Antineoplastic↗
PubMed2000

Mitral regurgitation: comprehensive assessment by echocardiography.

Two-dimensional and Doppler echocardiography have become the major modalities for the assessment of mitral regurgitation. The combined use of these techniques provides information regarding the morphology of the valvular apparatus as well as the severity of regurgitation. Transesophageal and three-dimensional echocardiography provide a more-detailed evaluation of valve morphology, which can be valuable in determining suitability for valve repair. In patients with severe mitral regurgitation, echocardiographic assessment of ventricular size and function plays a critical role in determining the optimal timing of surgery.

Echocardiography↗