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Biomedical subjects

H Kato

Publications and source records attributed to H Kato.

At least 145 records · Page 8Linked to original sources
PubMed2001

Nicotine exposure during pregnancy is a factor which influences serotonin transporter density in the rat brain.

We examined the effects of nicotine exposure during pregnancy on serotonin transporter (SERT) expression in the brain. Nicotine (6 mg/kg/day) was administered to pregnant rats via subcutaneous injections or infusion pumps. Irrespective of the route of administration, nicotine increased SERT density in the forebrain on postnatal day 22, but not in the other brain regions. Our results suggest that nicotine use by pregnant women might be an environmental factor influencing SERT expression in their children.

Animals↗
PubMed2001

In situ telomerase activity in pleural effusions: a promising marker for malignancy.

Telomerase activity in 16 pleural effusions was studied using an in situ telomerase repeat amplification protocol (TRAP) assay on cytospin preparations. Six of nine cytologically malignant specimens contained telomerase-positive cells (67%), and in two further specimens, suspicious positive cells were seen. Two of four atypical specimens contained telomerase-positive cells, whereas two benign cases were telomerase-negative. No mesothelial cells showed telomerase reactivity. Thus, telomerase activity was specific for malignancy and it was always found only in malignant cells. The results suggest that telomerase activity measured with this in situ method can be a valuable complement in the assessment of malignancy in pleural effusions.

Biomarkers, Tumor↗
PubMed2001

Alkali- and heat-treated porous titanium for orthopedic implants.

This study was carried out to investigate the effects of the alkali and heat treatments on the bone-bonding behavior of porous titanium implants. Porous titanium implants had a 4.6 mm solid core and a 0.7 mm thick porous outer layer using pure titanium plasma-spray technique. Three types of porous implants were prepared from these pieces: 1.control implant (CL implant) as manufactured 2.AW-glass ceramic bottom-coated implant (AW implant) in which AW-glass ceramic was coated on only the bottom of the pore of the implant 3.alkali- and heat-treated implant (AH implant), where implants were immersed in 5 mol/L NaOH solution at 60 degrees C for 24 h and subsequently heated at 600 degrees C for 1 h. The implants were inserted into bilateral femora of six dogs hemi-transcortically in a randomized manner. At 4 weeks, push-out tests revealed that the mean shear strengths of the CL, AW, and AH implants were about 10.8, 12.7, and 15.0 MPa, respectively. At 12 weeks there was no significant difference between the bonding strengths of the three types of the porous implants (16.0-16.7 MPa). Histologically and histomorphologically, direct bone contact with the implant surface was significantly higher in the AH implants than the CL and AW implants both at 4 and 12 weeks. Thus, the higher bonding strength between bone and alkali- and heat-treated titanium implants was attributed to the direct bonding between bone and titanium surface. In conclusion, alkali and heat treatments can provide porous titanium implants with earlier stable fixation.

Animals↗
PubMed2001

Bone bonding in bioactive glass ceramics combined with a new synthesized agent TAK-778.

We studied the stimulatory effects of TAK-778, a new synthetic 3-benzothiepin derivative that promotes osteoblast differentiation, in the bonding of bone to bioactive glass ceramic implants in rabbit tibiae. Smooth-surfaced, rectangular plates (15 x 10 x 2 mm) made of apatite-wollastonite-containing glass ceramic were implanted bilaterally into the proximal metaphyses of rabbit tibiae. Sustained-release microcapsules containing TAK-778 were packed into the medullary cavity in one limb and untreated microcapsules were packed into the contralateral limb to serve as a paired control. At 4, 8, and 16 weeks after implantation, bonding at the bone/implant interfaces was evaluated using a detaching test and histological examination of undecalcified specimens. The tensile failure load increased during weeks 4 to 16 in both groups; the tensile failure load in the TAK-778-treated group was significantly greater than that in the control group at each interval after implantation. Histologically, the TAK-778-treated specimens showed greater active new bone formation mainly in the medullary cavity and more extensive bonding between the implant and bone than the untreated specimens. The results of this study suggest that adding the bone formation-promoting TAK-778 to bioactive glass ceramic implants may significantly accelerate bone apposition to the implants and improve the bonding process at the interface. This would help to establish earlier and stronger bonding of orthopedic ceramic implants to the surrounding bone tissue.

Animals↗
PubMed2001

Malignant hepatic tumor detection with ferumoxides-enhanced MR imaging with a 1.5-T system: comparison of four imaging pulse sequences.

The purpose of our study was to compare observer performance in the detection of malignant hepatic tumors with ferumoxides-enhanced magnetic resonance (MR) images obtained with proton density-weighted spin-echo (SE), T2-weighted fast SE, T2*-weighted gradient-recalled-echo (GRE), and proton density-weighted echo-planar (EP) sequences. Ferumoxides-enhanced MR images obtained with the four sequences in 50 patients with 92 solid malignant and 64 nonsolid benign lesions were retrospectively analyzed. Image review was conducted on a segment-by-segment basis; a total of 397 liver segments was reviewed separately for solid and nonsolid lesions by three independent readers. Observer performance was evaluated with receiver operating characteristic analysis. Lesion-to-liver contrast-to-noise ratio was higher with SE and EP than with GRE and fast SE images for solid lesions (P < 0.05), and higher with fast SE and SE than with GRE images for nonsolid lesions (P < 0.01). Proton density-weighted SE and T2-weighted fast-SE images were superior to T2*-weighted GRE and proton density-weighted EP images for detection of malignant hepatic tumors. T2-weighted fast SE images were the best for detection of nonsolid lesions. T2-weighted fast SE images that were comparable to proton density-weighted SE images for solid tumor detection, that were the best for nonsolid lesion detection, and that had an acquisition time of one third to half of that of SE imaging may be able to replace SE images for ferumoxides-enhanced liver imaging.

Aged↗
PubMed2001

Nondenaturing two-dimensional electrophoretic analysis of loop-sheet polymerization of serpin, squamous cell carcinoma antigen-2.

Two homologous serine proteinase inhibitors (serpins), squamous cell carcinoma (SCC) antigen-1 and -2 were separated by nondenaturing two-dimensional electrophoresis combined with immunostaining to acquire further information on these proteins under physiological conditions. Polymers of SCC antigen-2 were detected in cytosolic extracts prepared from tumor tissues. The polymer formation of SCC antigen-2 was apparently decreased and the SCC antigen-2-synthetic peptide binary complexes were newly formed by the addition of synthetic peptide with sequences corresponding to residues from P14 to P2 in the reactive center loop of SCC antigen-2. On the other hand, the incubation with synthetic peptides having the sequence of the reactive center loop of SCC antigen-1 or antithrombin had no effect on polymerization of SCC antigen-2. These data suggest that the polymerization of SCC antigen-2 may occur spontaneously in vivo by the loop-sheet mechanism of serpin.

Antigens, Neoplasm↗
PubMed2001

Electrophoretic characterization of heat-stable squamous cell carcinoma antigen.

The aim of this study was to investigate the heat stability of squamous cell carcinoma (SCC) antigen, a tumor-associated serine proteinase inhibitor (serpin), in tumor tissue extract by electrophoretic methods. After heat treatment at 70 degrees C for 2 h, the tumor tissue extract showed a single main protein band of 45 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) which reacted with a monoclonal antibody specific for SCC antigen. The heat-stable SCC antigen was separated by two-dimensional electrophoresis (2-DE) into four spots with pI 6.4-5.9 and Mr 44500-45 000 of SCC antigen-1. Furthermore, the SCC antigen-1 still showed its inhibitory activity against a cysteine proteinase, papain, by gelatin zymography. These results suggest that heat treatment of protein sample at 70 degrees C for 2 h may be a useful method for a partial purification of SCC antigen-1 which can inhibit lysosomal cysteine proteinases such as cathepsin L, S, and K.

Antigens, Neoplasm↗
PubMed2001

Torn-off balloon tip of Z-5 atrial septostomy catheter.

Creation of atrial communication was performed in a newborn with critical aortic stenosis. After the success of the initial creation, balloon atrial septostomy using Z-5 catheter was performed. When catheter was pulled back, the tip of the balloon was torn off. This experience could be considered as noteworthy when using this catheter in patients with unusually thick atrial septum.

Angioplasty, Balloon, Coronary↗
PubMed2001

Carcinosarcoma of the uterus: immunohistochemical and genetic analysis of clonality of one case.

BACKGROUND: Carcinosarcomas of the uterus are characterized by admixtures of malignant epithelial and stromal cells, and their histogenesis remains controversial. CASE: An operated case of carcinosarcoma of the uterus in a 49-year-old woman is reported with clonal analysis. The tumor was composed of carcinomatous, sarcomatous, and transitional elements in the frontal wall of the uterine body and therefore was diagnosed as a carcinosarcoma. On immunohistochemical analysis, the sarcomatous component proved negative for epithelial membrane antigen and keratin while both components were positive for vimentin. Analysis of X-chromosome inactivation showed the same pattern throughout and additionally, the same K-ras and p53 mutations were homogeneously detected. Microsatellite instability analysis showed loss of heterozygosity at D5S346 in the sarcomatous but not the carcinomatous component. CONCLUSIONS: This tumor appears monoclonal in line with the combination tumor theory, with late divergence in genetic alteration in the sarcomatous elements.

Carcinosarcoma↗
PubMed2001

Venous hemangioma of the mediastinum.

Mediastinal hemangiomas are rare tumors. We present a case of venous hemangioma of the mediastinum. Computed tomography shows anterior mediastinal solid mass without enhancement effects. We believe that it is necessary to include a mediastinal hemangioma for differential diagnosis, when little or no enhancement effects are noted at early and delayed CT examination.

Adult↗
PubMed2001

Inter- and/or intra-organ distribution of mitochondrial C3303T or A3243G mutation in mitochondrial cytopathy.

Fatal infantile mitochondrial cytopathy associated with a C3303T mutation in the mitochondrial tRNA(Leu(UuR)) gene has been reported clinically, biochemically and genetically. Here we have analyzed the percentage of this mutation in various autopsied tissues, and also in single muscle fibers using a micromanupulator, to evaluate the correlation between the pathology and heteroplasmic condition using polymerase chain reaction/restriction fragment length polymorphism. A 5-month-old Japanese girl was admitted to our hospital showing generalized muscle weakness, hepatomegaly, and cardiomegaly with lactic acidosis, and died at 6 months of age. Skeletal muscle showed severe degenerating myopathy found to be full of ragged-red fibers (RRFs), an increased number of lipid droplets, and severe cytochrome c oxidase (COX) deficiency. Microscopically hepatocytes showed massive accumulation in lipid droplets, and the heart muscle showed a network pattern suggesting metabolic cardiomyopathy. The activities of respiratory chain enzyme complex I and complex IV in the skeletal muscle were significantly decreased to 23.4% and 5.0%, respectively, of the control value. The percentage of C3303T mutation in the patient tissues were variable, and ranged from 25% in the pancreas to 99% in the spinal cord. By single fiber analysis, the percentages of C3303T mutation in RRFs with COX negative (group 1; 42.4+/-7.0) and with COX positive (group 2; 58.2+/-5.8) were significantly higher than in non RRFs with normal COX staining (group 3; 10.7+/-6.3) (both P>0.001). Our patient showed a fatal infantile form of encephalopathy, myopathy and cardiomyopathy associated with widely distributed C3303T mutation in all of somatic cells.

DNA Mutational Analysis↗
PubMed2001

Anti-transforming growth factor-beta1 antibody transiently enhances DNA synthesis during liver regeneration after partial hepatectomy in rats.

The regulation of liver regeneration after partial hepatectomy (PHx) is complex and involves many different cytokines. We investigated the role of one of these, transforming growth factor-beta1 (TGF-beta1), an inhibitor of liver regeneration, in a Wistar male rat model, in which anti-TGF-beta1 antibody was injected immediately or 24 h after 70% PHx. Livers from treated animals contained an increased number of cells in S phase, according to 5-bromo-2'-deoxyuridine (BrdU) labeling 36 h after PHx. Antibody administration 24 h after PHx resulted in the highest peak of proliferation; moreover, peak MIB-5 labeling was also observed at that time. However, neither residual liver-weight-to-body-weight ratios nor regeneration rates differed significantly between any of the animals. Therefore, we also measured levels of serum TGF-beta1 and hepatocyte growth factor (HGF; an activator). With antibody administration at 0 or 24 h, TGF-beta1 levels were diminished at 24 or 36 h as compared with levels in control rats, but then rebounded, reaching a delayed peak at 48 or 72 h after PHx, respectively. Interestingly, there were also similar trends in HGF levels. These results indicate that TGF-beta1 may inhibit the G1 checkpoint, and serum TGF-beta1 concentration may influence HGF to regulate liver regeneration and to maintain homeostasis of proliferation after PHx.

Analysis of Variance↗
PubMed2001

Thymic carcinoid in a patient with multiple endocrine neoplasia type 1: report of a case.

We report herein the rare case of a 33-year-old man found to have a multiple endocrine neoplasia type 1 (MEN1)-associated carcinoid tumor in the thymus. A chest roentgenogram demonstrated an asymptomatic anterior mediastinal mass, 7 cm in diameter, and ultrasound-guided percutaneous Tru-Cut biopsy revealed a carcinoid tumor of the thymus. An extended thymectomy was performed through a median sternotomy and pathological examination confirmed the diagnosis of a thymic carcinoid tumor, which was mainly encapsulated with locally invasive growth into the pleura. Despite the absence of a family history of MEN1, he was treated for two pancreatic islet cell tumors, hyperparathyroidism, an adrenal tumor, and a retroperitoneal lipoma. MEN1 mutations were detected both in blood samples and pancreatic tumor tissues. He is now well without any evidence of tumor recurrence 27 months after the operation for the thymic carcinoid. MEN1 mutations were screened by direct nucleotide sequencing of all protein-coding regions of exons 2-10 of the MEN1 gene. Heterozygous germline mutation was detected in the blood sample analyses. Moreover, fresh-frozen pancreatic tumor tissues showed a loss of heterozygosity in the MEN1 region.

Adult↗
PubMed2001

Congenital bronchoesophageal fistula with Crohn's disease in an adult: report of a case.

A 65-year-old man was diagnosed to have Crohn's disease in 1989. In 1991, frequent bronchitis developed, and bronchoesophageal fistula was diagnosed by esophagography. On esophagography and aortography, the disease was diagnosed to be Type IV based on Braimbridge's classification accompanied by pulmonary sequestration. A thoracoscope-assisted fistelectomy was performed. This paper reports the findings of a fistelectomy assisted by thoracoscopy for the treatment of a Type IV bronchoesophageal fistula according to Braimbridge's classification accompanied by Crohn's disease.

Aged↗
PubMed2001

Successful surgical removal of an intrapulmonary aberrant needle under fluoroscopic guidance: report of a case.

We describe herein the successful surgical removal of an intrapulmonary aberrant needle. An asymptomatic 47-year-old woman underwent a routine chest X-ray which revealed a needle located in the right S8 area. We first tried to extract the needle; however, fluoroscopic examination confirmed that it had broken into two pieces and therefore, partial resection of the right S8 was performed. To avoid rethoracotomy, the operation was done under fluoroscopic guidance. An intrathoracic aberrant needle should always be removed surgically as soon as possible, even if the patient is asymptomatic, due to the possibility of its migration into the vessels and the development of lung abscess or pyothorax.

Female↗
PubMed2001

Decreased cerebrospinal fluid levels of beta-endorphin and ACTH in children with infantile spasms.

To investigate the pathophysiology of infantile spasms (IS), we measured the cerebrospinal fluid (CSF) levels of beta-endorphin (beta-EP), adrenocorticotropic hormone (ACTH), and corticotropin-releasing hormone (CRH) in 20 patients with IS, including 11 with the secondary form and 9 with the cryptogenic form of the disease. The findings were compared with those obtained in age-matched controls without neurologic disease. The CSF levels of beta-EP and ACTH were significantly lower in patients with IS than those in the controls. The CSF levels of CRH in patients with IS were lower, although, this trend was not significant. These reductions in the CSF levels of these neuropeptides could explain the impairment of the brain-adrenal axis in such patients. These results might support the hypothesis that, instead of originating from an increased abundance of CRH, which can act as a rapid and potent convulsant, some infantile seizures could be caused by an ACTH deficiency.

Adolescent↗