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Biomedical subjects

T Kono

Publications and source records attributed to T Kono.

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

[Fetal MRI: value and limitations--a review of 55 lesions].

OBJECTIVE: This study was undertaken to evaluate the usefulness and limitations of fetal MR imaging. MATERIALS AND METHODS: Fifty-five prenatal MRI examinations were performed, and the results were confirmed by postnatal follow-up or from pathological examination and clinical findings. All examinations were performed between 18 and 40 weeks of gestation without any premedication. A 1.5-Tesla superconductive MR imaging unit was used to obtain half-Fourier acquisition single-shot turbo spin-echo (HASTE) images. RESULTS: There were two false-positive cases on US. MRI allowed the diagnosis of serious unsuspected lesions such as hypoplastic lung and anorectal malformation. MRI was also useful for the precise diagnosis of ventriculomegaly. However, MRI missed two cases of spinal dysraphism and one case of laryngotracheoesophageal cleft. CONCLUSION: Fetal MRI is a valuable complementary tool when prenatal US is inadequate or doubtful. MRI is useful for the evaluation of pulmonary hypoplasia or hydrocephalus and may modify obstetric management. MRI may be able to diagnose spinal dysraphism by detecting mild widening of the CSF space. However, MRI currently is not useful for making a differential diagnosis between laryngotracheoesophageal cleft and esophageal atresia.

Congenital Abnormalities↗
PubMed2001

[Histopathological examination of tissues removed from the retinal surface during vitrectomy in idiopathic macular holes].

PURPOSE: We examined electron microscopically the tissues removed from the retinal surface in cases with idiopathic macular holes. MATERIALS AND METHODS: We performed vitrectomy for idiopathic macular holes in 43 eyes from June 1994 to December 1998 at Fukuoka University Chikushi Hospital. The removed tissues were evaluated with transmission electron microscope in only 8 of the 43 eyes. All cases underwent 3 port vitrectomy. After occurrence of posterior vitreous detachment, epiretinal tissues were removed around the macular hole using a micro-hook needle. RESULTS: All tissues were transparent under an operating microscope, and they curled naturally. Histopathological examination showed that the removed tissues were from 2 to 6.5 microns thick. All tissues were composed mainly of extracellular matrix. There were type 2 collagen fibers in 6 eyes and basement membrane-like structures in 2 eyes. There were few cell components. All cases had the macular hole closed by the first surgery. Four eyes had improved visual acuities of more than 2 lines. The remaining 4 eyes had the same visual acuity as before the operation. CONCLUSION: Residual vitreous on the retinal surface was the main component of the transparent tissues removed from the retinal surface during vitrectomy.

Adult↗
PubMed2001

[Guidelines for antibiotic agents in the field of respiratory tract surgery].

This paper provides information on the use of antibiotic agents during the postoperative period from three aspects. 1) It is important to evaluate the risk factors of postoperative infection based on the patient's preoperative condition. Diseases treated with respiratory tract surgery are frequently caused by heavy smoking. Therefore it must be remembered that the patients may have low respiratory function. 2) In the prevention of postoperative infection, the special circumstances after respiratory surgery (e.g., the disintegration of the clearance system in the airway caused by the dissection of lymph nodes, the suppression of respiration, and cough caused by thoracotomy accompanied by resection of the ribs) must be considered. Therefore we usually administer antibiotic agents for 3 to 4 days. In general, we select second-generation cephalosporins, be cause gram-negative rod infection frequently occurs. 3) Postoperative infection is diagnosed based on fluctuations in fever, laboratory data (number of white blood cells and C-reactive protein), chest X-ray findings, and properties of drainage fluid. When bacteria are not identified, we must consider MRSA as a gram-positive bacterium and Pseudomonas aeruginosa as a gram-negative bacterium. After the identification of bacteria causing the infection, the antibiotic agents may be changed based on the results of sensitivity tests. The appropriate usage of antibiotic agents in the field of respiratory tract surgery is discussed based on actual clinical experience in our department.

Anti-Bacterial Agents↗
PubMed2000

Effects of arctiin on PhIP-induced mammary, colon and pancreatic carcinogenesis in female Sprague-Dawley rats and MeIQx-induced hepatocarcinogenesis in male F344 rats.

Chemopreventive effects of arctiin, a lignan isolated from Arctium lappa (burdock) seeds, on the initiation or post initiation period of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induced mammary carcinogenesis in female rats and on 2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)-associated hepatocarcinogenesis in male rats were examined. In experiment 1, female Sprague-Dawley (SD) rats were given intragastric doses of 100 mg/kg body wt of PhIP once a week for 8 weeks as initiation. Groups of 20 rats each were treated with 0.2 or 0.02% arctiin during or after PhIP initiation. Control rats were fed 0.2 or 0.02% arctiin, or basal diet alone during the experimental period. Animals were killed at the end of week 48. Although the incidence of mammary carcinomas did not significantly differ among the PhIP-treated groups, multiplicity was significantly decreased in rats given 0.2 (0.7+/-0.7, P<0.05) or 0.02% (1.0+/-1.1, P<0.05) arctiin after PhIP initiation as compared with the PhIP alone controls (2.1+/-2.5). The average number of colon aberrant crypt foci was also significantly decreased in these two groups. Pancreas acidophilic foci were induced in PhIP treated animals with slight decrease in the multiplicity with arctiin during the initiation phase. For liver carcinogenesis, groups of 15 male F344 rats were given a single intraperitoneal injection of diethylnitrosamine (DEN) and starting 2 weeks later, they were administered 0.03% MeIQx in the diet, MeIQx together with 0.5% arctiin, 0.1% arctiin or basal diet for 6 weeks. They were subjected to two-third partial hepatectomy 3 weeks after DEN initiation and killed at the end of week 8 for glutathione S-transferase placental form (GST-P) immunohistochemistry. The numbers and areas of preneoplastic GST-P positive foci were elevated by the treatment with MeIQx, and further increased by the simultaneous treatment with arctiin. These results indicate that arctiin has a protective effect on PhIP-induced carcinogenesis particularly in the mammary gland in the promotion period. On the other hand, it may have a weak co-carcinogenic influence on MeIQx-induced hepatocarcinogenesis. In addition, the results suggested that PhIP is a weak pancreatic carcinogen in female SD rats, targeting acinar cells.

Animals↗
PubMed2000

Human fatty acid omega-hydroxylase, CYP4A11: determination of complete genomic sequence and characterization of purified recombinant protein.

The gene of the human fatty acid omega-hydroxylase, CYP4A11, has been isolated from a human BAC library, and its complete genomic sequence has been determined. The CYP4A11 gene spanned 12,568 bp and contained 12 exons. The known PPAR recognition elements (PPRE), which were reported to be involved in the induction of CYP4A6 by clofibric acid, were not observed within the 5'-flanking region of the CYP4A11 gene. The recombinant CYP4A11 protein expressed in Escherichia coli using the pCWOri expression vector was purified to an almost electrophoretically homogeneous state with a specific content of 6.4 nmol of P450/mg of protein. This P450 exhibited omega-hydroxylation activity toward laurate, with a turnover number of 14.7 nmol/min/nmol of P450. The apparent K(m) and V(max) values were 56.7 microM and 15.2 nmol/min/nmol of P450, respectively. It also showed omega-hydroxylation activity toward palmitate, with a turnover number of 0.78 nmol/min/nmol of P450. Although several reports from other groups described that CYP4A11 preparations catalyzed omega-hydroxylation of arachidonic acid, our purified recombinant protein exhibited no activity toward arachidonic acid nor prostaglandin A(1).

Amino Acid Sequence↗
PubMed2000

Complete resection of cardiac leiomyosarcoma extending into the pulmonary trunk and right pulmonary artery.

A cardiac leimyosarcoma is an extremely rare tumor. We report a case of complete resection of a cardiac leiomyosarcoma extending into the pulmonary trunk and the right pulmonary artery using the Freestyle bioprosthesis (Medtronic, Inc, Minneapolis, MN) and Xenomedica graft (Baxter Healthcare Corp, Horw, Switzerland). Extensive resection and reconstructive surgery with the addition of radiotherapy prolonged the patient's life.

Adult↗
PubMed2000

Expression of vascular endothelial growth factor and angiogenesis in cardiac myxoma: a study of fifteen patients.

OBJECTIVE: To clarify the association between angiogenesis and the clinicopathologic features in cardiac myxoma, vascular endothelial growth factor expression in the myxoma was examined by using reverse transcriptase polymerase chain reaction and immunohistochemistry, and the microvessel density was determined by counting microvessels in the myxoma by using immunostaining for platelet endothelial cell adhesion molecule 1. METHODS: Seven fresh-frozen and 15 formalin-embedded tissues were analyzed by means of reverse transcriptase polymerase chain reaction and immunostaining for vascular endothelial growth factor, respectively. The microvessel density was measured in the 15 formalin-embedded tissues. Furthermore, immunostaining for proliferating cell nuclear antigen was performed, and the proliferating cell nuclear antigen-labeling index was calculated. RESULTS: All of the 7 analyzed myxomas were positive for vascular endothelial growth factor messenger RNA, as determined by means of reverse transcriptase polymerase chain reaction, whereas atrial septum and atrium tissues were negative. Positive immunohistochemical reaction for vascular endothelial growth factor was observed in the cells of all 15 myxomas. The size of myxomas with high vascular endothelial growth factor expression was smaller than that of myxomas with low vascular endothelial growth factor expression. The microvessel density in myxomas with high vascular endothelial growth factor expression was higher than that in myxomas with low vascular endothelial growth factor expression. There was an inverse correlation between the tumor size and the ratio of the microvessel density in the central part to the microvessel density in the peripheral part of myxomas. Furthermore, there was an inverse correlation between the proliferating cell nuclear antigen-labeling index and the tumor size, and the prolferating cell nuclear antigen-labeling index in myxomas with high vascular endothelial growth factor expression was higher than that in myxomas with low vascular endothelial growth factor expression. CONCLUSIONS: Cardiac myxomas produce vascular endothelial growth factor, which probably induces angiogenesis for tumor growth.

Adult↗
PubMed2000

Differential interaction of Cbl with Grb2 and CrkL in CD2-mediated NK cell activation.

Natural killer (NK) cells participate in both innate and adoptive immunity by their prompt secretion of cytokines and by their ability to lyse virally infected cells or tumor cells. CD2 is surface glycoprotein receptors and crucial for NK cell activation. However, molecular events involved in CD2-mediated NK cell activation have not been fully elucidated. Cbl-Grb2 and Cbl-CrkL interactions have been implicated in T cell and B cell receptor, and cytokine receptor signaling. Here we analyzed tyrosine phosphorylation and interactions of Cbl with adapter proteins, Grb2 and CrkL, in NK3.3 cells. CD2 crosslinking results in the marked tyrosine phosphorylation of Cbl in an antibody concentration- and time-dependent manner. Immunodepletion studies reveal that Grb2-associated tyrosine phosphorylated p120 kDa protein is Cbl. In vitro binding studies using GST-fusion proteins demonstrate that Cbl constitutively associates with the SH3 domains of Grb2, with a preference for the amino-terminal domain. In addition, we demonstrate that CrkL associates with a large portion of tyrosine phosphorylated Cbl after CD2 stimulation of NK3.3 cells. In contrast to constitutive Cbl association with Grb2, tyrosine phosphorylated Cbl interacts with CrkL via its SH2 domain only after CD2 stimulation. Although the precise roles of interactions of Cbl with Grb2 and CrkL in NK cell activation remains to be elucidated, their tyrosine phosphorylation, in addition to the multiple protein interactions described here, strongly suggest that interactions of Cbl with Grb2 and CrkL may play pivotal roles in CD2-mediated NK cell activation.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Scleroderma-like reaction induced by uracil-tegafur (UFT), a second-generation anticancer agent.

UFT, a combination of uracil and tegafur, is a second-generation anticancer agent. UFT has been used in Japan, other Asian countries, South America, and Russia. Recently, UFT has been extensively studied for colorectal, pancreatic, and various types of cancer in North America and Europe, especially with leukovorin. We report a case of a scleroderma-like reaction induced by long-term administration of UFT. This is the first report of UFT-induced scleroderma-like reaction.

Antimetabolites, Antineoplastic↗
PubMed2000

Impairment of gastric and jejunal myoelectrical activity during rectal distension in dogs.

It is known that distension of the rectum induces gastric hypomotility and delays gastric emptying. Its effect on gastrointestinal myoelectrical activity has not been well studied, however. The aim of this study was to investigate the effects of rectal distension on gastrointestinal myoelectrical activity in dogs. Six hound dogs implanted with electrodes on the serosa of the stomach and proximal jejunum were studied. The protocol consisted of a 30-min baseline recording and another 30-min recording during rectal distension. Gastric myoelectrical activity was severely impaired by rectal distension. The dominant power was significantly decreased from -2.79 +/- 0.52 dB at baseline to -4.84 +/- 1.26 dB during distension (P < 0.05). The percentage of normal 4-6 cycles per minute gastric slow waves was reduced from 95.08 +/- 1.11% to 83.63 +/- 4.00% (P < 0.02), and the percentage of tachygastria was increased during distension (0.33 +/- 0.19% vs 6.03 +/- 1.27%, P < 0.02). The instability coefficient of the dominant frequency was significantly increased (0.134 +/- 0.012 vs 0.326 +/- 0.074, P < 0.05). The percentage of slow wave coupling was reduced from 93.99 +/- 0.76% to 73.43 +/- 2.07% (P < 0.00003). In the small bowel, only the instability coefficient of dominant frequency showed a significant increase during distension. Other parameters were not affected by rectal distension. We conclude that rectal distension severely impairs gastric myoelectrical activity. The induced gastric dysrhythmia and reduced slow wave amplitude and coupling may be the underlying pathophysiology of gastric hypomotility and delayed gastric emptying observed during rectal distension.

Animals↗
PubMed2000

Granulomatous slack skin: successful treatment with recombinant interferon-gamma.

Granulomatous slack skin is a rare variant of indolent cutaneous lymphoma, characterized by a cutis laxa-like clinical appearance and widespread granulomatous infiltration. A 25-year-old man had suffered from slowly progressive infiltrative, scaly and atrophic plaques and flaccid nodules with deep induration in the axillae, trunk and thighs. Histopathologically, dense lymphoid cell infiltration with numerous multinucleated giant cells (MGC) throughout the dermis to the subcutaneous tissue was observed. T-cell receptor gene rearrangement was detected in the skin lesions. Granulomatous infiltration with MGC was found in enlarged lymph nodes and the liver. Acute exacerbation was successfully treated with systemic recombinant interferon-gamma.

Adult↗
PubMed2000

The paternal methylation imprint of the mouse H19 locus is acquired in the gonocyte stage during foetal testis development.

BACKGROUND: Germline-specific differential DNA methylation that persists through fertilization and embryonic development is thought to be the 'imprint' distinguishing the parental alleles of imprinted genes. If such methylation is to work as the imprinting mechanism, however, it has to be reprogrammed following each passage through the germline. Previous studies on maternally methylated genes have shown that their methylation imprints are first erased in primordial germ cells (PGCs) and then re-established during oocyte growth. RESULTS: We have examined the timing of the reprogramming of the paternal methylation imprint of the mouse H19 gene during germ cell development. In both male and female PGCs, the paternal allele is partially methylated whereas the maternal allele is unmethylated. This partial methylation is completely erased in the female germline by entry into meiosis, establishing the oocyte methylation pattern. In the male germline, both alleles become methylated, mainly during the gonocyte stage, establishing the sperm methylation pattern. CONCLUSION: The paternal methylation imprint of H19 is established in the male germline and erased in the female germline at specific developmental stages. The identification of the timings of the methylation and demethylation should help to identify and characterize the biochemical basis of the reprogramming of imprinting.

Animals↗
PubMed2000

Purification and cloning of pierisin-2, an apoptosis-inducing protein from the cabbage butterfly, Pieris brassicae.

The cabbage butterfly Pieris rapae contains a strong apoptosis-inducing substance, pierisin, against human cancer cell lines, which is thought to act via ADP-ribosylation. Here we report the purification and cloning of an apoptosis-inducing substance, designated as pierisin-2, from another cabbage butterfly, Pieris brassicae. Pierisin-2 was purified from pupae by sequential chromatography and its cytotoxic and apoptosis-inducing activities to various cancer cells were similar to those of pierisin, designated as pierisin-1, from P. rapae. cDNA cloning of pierisin-2 was performed on the basis of the partial amino-acid sequence. The nucleotide sequence indicated that the cDNA encodes an 850-amino-acid protein with a calculated molecular mass of 97 986. The deduced amino-acid sequence of pierisin-2 was 91% identical with that of pierisin-1. In vitro expressed protein in the reticulocyte lysate exhibited apoptosis-inducing activities against human gastric carcinoma TMK-1 and cervical carcinoma HeLa cells, similar to the purified native pierisin-2 from the pupae. Pierisin-2 shows regional sequence similarities with certain ADP-ribosylating toxins such as the A-subunit of cholera toxin. The results from site-directed mutagenesis at Glu165, a conserved residue among ADP-ribosylating enzymes necessary for NAD binding, and from experiments with ADP-ribosylating enzyme inhibitors suggested that pierisin-2 could be considered as an ADP-ribosylating toxin like pierisin-1.

ADP Ribose Transferases↗