Biomedical subjects

T Kojima

Publications and source records attributed to T Kojima.

At least 505 records · Page 28Linked to original sources

PubMed1993

Increased soluble ICAM-1 in tracheal aspirates of infants with bronchopulmonary dysplasia.

Raised concentrations of soluble intracellular adhesion molecule 1 (sICAM-1) in tracheal aspirates from premature infants may predict development of bronchopulmonary dysplasia (BPD). We measured sICAM-1 in tracheal aspirates and serum samples from 15 newborn babies (9 with BPD, 6 without BPD) at 2-4, 6-7, and 12-14 days of age. sICAM-1 concentrations in tracheal aspirates were significantly raised at 6-7 and 12-14 days of age in infants who later developed BPD compared with infants who did not develop BPD. Serum samples from the two groups did not differ significantly in sICAM-1. Raised sICAM-1 in tracheal aspirate was a good predictor of lung injury in infants who later developed BPD.

Antigens, CD↗

PubMed1993

Chemopreventive effects of dietary D,L-alpha-difluoromethylornithine, an ornithine decarboxylase inhibitor, on initiation and postinitiation stages of diethylnitrosamine-induced rat hepatocarcinogenesis.

The modifying effects of dietary administration of D,L-alpha-difluoromethylornithine (DFMO) during initiation or postinitiation phase on the hepatocarcinogenesis initiated by diethylnitrosamine (DEN) were investigated in male F344 rats. A total of 129 animals were divided into seven groups. Groups 1-5 were given the drinking water containing 40 ppm DEN for 5 weeks, starting at 7 weeks of age. Groups 2 and 3 were fed the diets mixed with 500 and 1000 ppm DFMO, respectively, for 7 weeks, starting at 6 weeks of age. Groups 4 and 5 were given the diets containing 500 and 1000 ppm DFMO, respectively, starting 1 week after DEN exposure and maintained on these diets until the end of the study (Week 32). Rats in group 6 were fed the DFMO diet (1000 ppm) alone during the experiment. Group 7 served as an untreated control. At the end of the study, the incidences of liver cell foci (resistant iron accumulation or positive for glutathione S-transferase placental form) and hepatocellular neoplasms along with polyamine levels in the liver were measured. Also, morphometric analysis of silver-stained nucleolar organizer regions proteins as cell proliferation activity in liver cells was performed. The mean incidences and areas of foci in rats given DEN and DFMO in groups 2-5 were significantly lower than those of group 1 (P < 0.01). The frequencies of liver cell tumors in group 3 (50%), 4 (24%), and 5 (45%) were significantly reduced compared to that of group 1 (100%) (P < 0.01). The multiplicities of neoplasms in group 2 (1.15/rat), 3 (0.65/rat), 4 (0.35/rat), and 5 (0.95/rat) were significantly smaller than that of group 1 (3.34/rat) (P < 0.001). Although the polyamine levels of liver tissues among the groups showed no clear differences among the groups, the number and area of silver-stained nucleolar organizer regions proteins/nucleus in rats given DEN and DFMO (groups 2-5) were significantly lower than those of group 1. These results indicate that the feeding of DFMO during the initiation or postinitiation stage clearly inhibited DEN-induced rat hepatocarcinogenesis and that such inhibition may be due to alteration in cell proliferation activity caused by DFMO.

Animals↗

PubMed1993

Chemoprevention of colon carcinogenesis by the natural product of a simple phenolic compound protocatechuic acid: suppressing effects on tumor development and biomarkers expression of colon tumorigenesis.

Our previous study has shown that dietary administration of protocatechuic acid (PCA) acts as potential chemopreventive agent in inhibiting diethylnitrosamine-induced liver carcinogenesis in male F344 rats. The present study was designed to determine the modifying effect of PCA on azoxymethane (AOM)-induced colon carcinogenesis in male F344 rats and the effect on intermediate biomarkers, i.e., colonic mucosal ornithine decarboxylase activity and colonic epithelial proliferation, which can be used as effective predictors of colon cancer. Staring at 6 weeks of age, groups of animals were fed the basal diet and experimental diet containing PCA at dose levels of 250, 500, and 1000 ppm. At 7 weeks of age, all animals except the PCA alone group (1000 ppm) and untreated controls were given s.c. injections of AOM at a dose level of 15 mg/kg body weight/week for 3 weeks. PCA at 3 doses was fed during the initiation phase (before 1 week, during, and after 1 week of AOM exposure) or postinitiation phase (for 28 weeks starting 1 week after the last injection of AOM). All animals were then killed at 32 weeks after the start and colonic tumor incidence and multiplicity were determined. Animals intended for cell proliferation study were given injections of bromodeoxyuridine/5-fluoro-2'-deoxyuridine (1 ml/100 g body weight) 1 h prior to be killing. The rate of colonic cell proliferation in the distal portion was assessed by immunohistochemistry using antibromodeoxyuridine and by counting silver-stained nucleolar organizer regions protein. The colonic mucosal ornithine decarboxylase activity was also measured at the termination. The results indicate that dietary PCA administration at 500 and 1000 ppm during the initiation or postinitiation phase significantly inhibited intestinal carcinogenesis induced by AOM as revealed by the reduction of tumor incidence and multiplicity. The data also demonstrate that PCA at 500 ppm and 1000 ppm significantly inhibited bromodeoxyuridine labeling index and also silver-stained nucleolar organizer regions protein number at three doses when animals were fed PCA at the initiation or postinitiation stage. Also, feeding of PCA at 1000 ppm during the initiation and postinitiation phase exerted a pronounced inhibitory effect on the colonic ornithine decarboxylase levels. PCA feeding did not cause any toxicity. These results demonstrate that PCA is a possible new chemopreventive agent for colon carcinogenesis through the suppression of manifestation of intermediate biomarkers induced by AOM, although the precise mechanisms of PCA-induced inhibition during the initiation and postinitiation phases remain to be elucidated.

Adenocarcinoma↗

PubMed1993

Chemoprevention of diethylnitrosamine-induced hepatocarcinogenesis by a simple phenolic acid protocatechuic acid in rats.

The modifying effect of dietary protocatechuic acid (PCA) given during the initiation phase or the postinitiation phase on liver carcinogenesis induced by diethylnitrosamine (DEN) was studied in male F344 rats. At 6 weeks of age, rats were divided into experimental and control groups and fed the diets containing 500 and 1000 ppm PCA or the basal diet. At 7 weeks of age, all animals except PCA alone and control groups were given DEN at 40 ppm in the drinking water for 5 weeks to induce liver cell neoplasms. Seven days after the DEN exposure, groups of animals fed the PCA diets and continued on these diets until the end of the study. All animals were necropsied during the 37 weeks after the start of the experiment in order to determine the incidences of preneoplastic liver cell foci and neoplasms. Hepatic ornithine decarboxylase activity was also measured in all animals at the termination of the study. Dietary PCA administered at both doses during the initiation phase significantly inhibited the incidence of altered hepatocellular foci resistant for iron accumulation or those positive for glutathione S-transferase placental form and the liver cell tumor incidence and multiplicity. Similarly, the numbers of liver cell foci and neoplasms and tumor multiplicity were significantly reduced in groups fed the PCA diets at the postinitiation stage of carcinogenesis. Hepatic ornithine decarboxylase activity was reduced in DEN-treated animals fed the PCA diets compared to those given DEN alone. Although the precise mechanisms of PCA-induced inhibition of hepatocarcinogenesis remain to be elucidate, it is likely that the inhibitory effects during the initiation and postinitiation phases may be due to alteration in hepatic ornithine decarboxylase activity under the present experimental condition.

Animals↗

PubMed1993

A phenotypically neutral dimorphism of protein S: the substitution of Lys155 by Glu in the second EGF domain predicted by an A to G base exchange in the gene.

During the course of structural gene analysis of a family with type III protein S deficiency, we found a novel DNA polymorphism: an A or G variation at nucleotide 732 in exon 6 of the PS-alpha gene. This A to G mutation would lead to a substitution of Lys155 by Glu in the second EGF domain. Linkage study with restriction enzyme analysis using mutagenic PCR strategy showed that the same mutation was also present in three other members of the patient's family and two individuals from an unrelated kindred, while they all had normal amounts of both immunological and functional PS levels. Restriction enzyme analysis of 182 normal Japanese genomic samples showed that 1.65% of normal population were heterozygotes for this variant allele. These findings suggest that this substitution in exon 6 is not responsible for the type III protein S deficiency but a phenotypically neutral polymorphism. Hereby we designate this polymorphism as PS-732.

Adolescent↗

PubMed1993

Structure and expression of hedgehog, a Drosophila segment-polarity gene required for cell-cell communication.

The complete nucleotide sequence of the coding region of hedgehog (hh), a segment-polarity gene in Drosophila melanogaster, was determined. The gene was found to include three exons which would encode a 421- (or 471-) amino acid (aa) polypeptide with a long hydrophobic stretch. The hh mRNA was about 2.3 kb long and expressed throughout development. The hh expression in an embryo occurred in stripes, while that in imaginal discs occurred in the posterior compartment. As a whole, the spatial expression pattern of hh mRNA was very similar to that of engrailed (en), a homeobox gene required for the formation of the anterior-posterior compartment boundary. Unlike en, no hh expression was observed in the central nervous system.

Animals↗

PubMed1993

Human ryudocan core protein: molecular cloning and characterization of the cDNA, and chromosomal localization of the gene.

We have isolated a series of overlapping cDNA clones encoding a 2,628 bp transcript, which potentially codes for a 198 amino acid protein with predicted molecular mass of 21,641 daltons, for the human ryudocan core protein. The deduced core proteins of the human and the rat ryudocan have high structural conservation, particularly in the NH2 and COOH terminus regions of the putative mature core protein, including the combined transmembrane/cytoplasmic domains with conserved positions of all 4 tyrosine groups and 3 conserved glycosaminoglycan chain attachment regions, which might serve important roles for biological function of ryudocan. A major 2.7 kb transcript was detected in all tissues tested, with relatively high levels of expression observed in mRNA from lung, liver, skeletal muscle and kidney. A minor 1.9 kb transcript was also observed in some of tissues, which would be caused by alternative polyadenylation. Human ryudocan gene has been localized on the chromosome 20q12 by fluorescence in situ hybridization.

Amino Acid Sequence↗

PubMed1993

Chemoprevention of oral carcinogenesis by DL-alpha-difluoromethylornithine, an ornithine decarboxylase inhibitor: dose-dependent reduction in 4-nitroquinoline 1-oxide-induced tongue neoplasms in rats.

The modifying effect of three doses of DL-alpha-difluoromethylornithine (DFMO) given p.o. during the post-initiation phase of tongue carcinogenesis initiated by 4-nitroquinoline 1-oxide (4-NQO) was studied in male ACI/N rats. Animals were given 4-NQO at 20 ppm for 8 weeks in the drinking water to induce tongue neoplasms. One week after the stop of 4-NQO treatment, rats were transferred to the drinking water containing DFMO at concentrations of 100, 1000, and 2000 ppm for 25 weeks. The other groups consisted of rats given 2000 ppm DFMO alone or untreated rats. Thirty-four weeks after the start of the experiment, all animals were necropsied, and the incidences of neoplasms and preneoplastic lesions in the tongue, polyamine levels in the bloods and tongue tissues, and cell proliferation estimated by the number and area of silver-stained nucleolar organizer regions in the tongue epithelium were compared among the groups. Feeding of DFMO at all doses significantly inhibited the incidence of tongue neoplasms compared to the group given 4-NQO alone. DFMO at levels of 1000 and 2000 ppm significantly reduced the incidence of preneoplastic lesions of the tongue. Results analyzed by the linear regression method suggested a dose-dependent inhibition in the incidences of neoplastic and preneoplastic lesions of the tongue with increasing levels of DFMO. Increased levels in polyamines in the blood and tongue tissue were significantly suppressed by the treatment of DFMO. Also, silver-stained nucleolar organizer region indices were significantly reduced by the DFMO exposure. These results indicate that increasing levels of DFMO in the drinking water inhibited 4-NQO-induced tongue carcinogenesis in a dose-dependent manner and such inhibition was related to reduction in the polyamine levels of blood and tissue and decrease in the cell proliferation.

4-Nitroquinoline-1-oxide↗

PubMed1993

Increase in portal flow induces c-myc expression in isolated perfused rat liver.

We examined expression of the c-myc oncogene in isolated perfused livers to elucidate the mechanisms involved in triggering the proliferation of hepatocytes after partial hepatectomy (PH). During perfusion with a 1:1 mixture of Dulbecco's modified Eagle's medium and the oxygen transport fluid FC-43, rat livers were two-thirds resected (PH), and further perfused for 1 1/2 hours at the physiological portal flow throughout the perfusion. Expression of c-myc in the perfused livers with PH(+) was ten times higher than in those with PH(-). Furthermore, expression of c-myc in the PH(-) livers perfused with a threefold volume of the physiological portal flow was 5-10 times higher than that in the livers perfused with the physiological portal flow. The perfusates that passed through the livers did not induce DNA synthesis of primary cultured hepatocytes. These results suggest that an increase in the portal flow volume may act as a trigger for hepatocyte proliferation after PH.

Animals↗

PubMed1993

Effect of the composition of vitrification media on survival of rabbit embryos.

A total of 448 rabbit morula stage embryos were used to examine the effect of modified vitrification procedure and vitrification media containing 10% (1.36 M) glycerol, 20% (2.72 M) 1,2-propanediol, and 1 M sucrose. The best result, 89.5% embryos developed in vitro, was obtained after equilibration, vitrification, and dilution of embryos using media in which the salt concentration was maintained constant on a molar basis. Media prepared on a molal basis were more toxic and/or less efficient.

Animals↗

PubMed1993

Cryoprotective effect of egg yolk in cryopreservation of porcine embryos.

The objective of the present study was to assess the effect of egg yolk supplementation in solutions for either cooling or freezing of porcine embryos. In Experiment 1, porcine embryos collected on Day 3 to 7 (Day 0 = onset of estrus) were allocated to 12 experimental groups according to their developmental stages (four-cell to compact morula, early blastocyst to blastocyst, expanded blastocyst, and hatched blastocyst) and the concentrations of egg yolk (0, 5, and 10% (v/v)) for cooling to 0 degrees C. Whereas no embryos ranging from four-cell to blastocyst survived, the 10-min exposure to 0 degrees C despite egg yolk supplementation, expanded blastocysts and hatched blastocysts allocated to egg yolk-supplemented groups survived cooling to 0 degrees C. In Experiment 2, porcine expanded and hatched blastocysts collected on Day 6 or 7 were assigned to six experimental groups according to their developmental stages and the type of cryoprotectant used (10% glycerol, 11% Me2SO, and 10% propylene glycol) for freezing at -196 degrees C. All freezing solutions contained either 5 or 10% egg yolk. The embryos were equilibrated with one of the freezing solutions, cooled from 25 to -7 degrees C at 1 degree C/min, seeded at that temperature, then cooled to -36 degrees C at 0.3 degree C/min, and finally plunged into liquid nitrogen for storage. The frozen embryos were thawed by immersion in 37 degrees C water. After the cryoprotectants were removed by dilution, the embryos were cultured for 48 h to evaluate their viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Cryopreservation of porcine blastocysts by vitrification.

The objective of this study was to assess the possibility of cryopreservation of porcine expanded and hatched blastocysts by vitrification. The following four types of vitrification solutions were applied in this study: (i) EFT, a mixture of 7.2 M ethylene glycol, 0.003 M ficoll, and 0.3 M trehalose; (ii) DAP213, 2 M dimethyl sulfoxide, 1 M acetamide, and 3 M propylene glycol; (iii) DAP213-T, DAP213 supplemented with 0.3 M trehalose; and (iv) EPT, 4 M ethylene glycol, 3.1 M propylene glycol and 0.3 M trehalose. The embryos collected on Days 5 to 7 (Day 0 = onset of estrus) were allocated to eight experimental groups according to the types of vitrification solution and the developmental stage. In the toxicity test, the embryos were equilibrated in the respective vitrification solutions either in a single step or in four steps and then transferred to 1 M sucrose in a single step at 22 degrees C without cooling. As a whole, the viabilities of embryos equilibrated in the solutions were lower than those of control embryos. The stepwise equilibration was superior to a single-step equilibration in the in vitro survival of, especially, expanded blastocysts after dilution. No significant difference was observed between the vitrification solutions for the four-step method. In the vitrification test, the embryos were equilibrated in the solutions by the four-step method, loaded into a 0.25-ml plastic straw, and plunged into liquid nitrogen. Although viable embryos were obtained after warming from all of the combinations except the hatched blastocyst-EPT group, viabilities were further reduced by cooling (range of reduction rates: 60 to 100%). The possible cause of low survival after warming is also discussed concerning the cryophysical properties of vitrification solutions.

Acetamides↗

PubMed1993

Congenital, multiple, bilateral, trigger digits in a child.

Congenital triggering of a digit other than the thumb is a rare. A nine year old boy has been treated for congenital, multiple trigger digits in addition to the thumb. The operative findings were only slight thickening of the flexor pulley and noticeable fusiform swelling of the flexor tendons.

Child↗

PubMed1993

MR imaging of traumatic hepatic laceration: evaluation and course of healing after surgery.

Six patients with hepatic laceration underwent magnetic resonance imaging (MRI) at 0.5T. Acute hepatic laceration was slightly hypointense on T1-weighted spin-echo (SE) image, and hyperintense on T2- and proton-weighted SE images. Subacute laceration was heterogeneously intense on T1-weighted image and hyperintense on T2- and proton-weighted images. Consistent changes in signal intensity of postoperative hepatic laceration were observed. On T1-weighted image, the signal intensity at first increased and then decreased from periphery to the center. On the T2- and proton-weighted images, the laceration was uniformly hyperintense relative to the liver prior to the appearance and growth of a hypointense ring at its periphery. The appearance of the above changes in signal intensity was also observed in postoperative recurrent hemorrhage. The postoperative biloma had none of the above changes in signal intensity. Our cases show that MRI is effective in the evaluation of hepatic laceration and in the assessment of the course of healing after operation.

Adolescent↗

PubMed1993

The trans-sphincteric and trans-sacral approaches for the surgical excision of rectal and presacral lesions.

In the decade from 1981 to 1990, 30 patients underwent a posterior transsacral approach at the Aichi Medical University Hospital for their benign or malignant rectal lesions. The operation was classified into two procedures, consisting of the transsphincteric approach and transsacral approach, in order to cope with the condition of the anal sphincter muscles; whether they were divided or not. Eleven rectal tumors were successfully excised through the opened-up rectum by using the transsphincteric approach, and excellent results were obtained without any postoperative complications. Using the transsacral approach, 2 presacral dermoid cysts and 11 rectal lesions were easily removed under direct vision. Their prognoses were excellent. The transsacral approach was also applied for the resection of recurrent rectal cancers after a radical, abdominoperineal resection in 6 patients suffering from intolerable local symptoms. All the patients were free from these uncomfortable local symptoms after the surgery. The posterior transsacral operation is thus considered to be of value not only for resecting benign rectal and presacral lesions, but also for resecting malignant rectal tumors in frail subjects who are unfit for radical operation and/or recurrent rectal cancer.

Adenoma, Villous↗

PubMed1993

Chronological changes of MRI findings on striatal damage after acute cyanide intoxication: pathogenesis of the damage and its selectivity, and prevention for neurological sequelae: a case report.

A 31-year-old male technician in an electroplating factory, who had been suffering from the temporal lobe epilepsy for 24 years and from hypertension for 2 years, took an unknown amount of potassium cyanide apparently over the lethal dose, in an attempt to commit suicide. He was treated successfully and survived without any neurological sequelae. The electroencephalograms and the nature of the seizures were not different before and after the poisoning. The T2-weighted magnetic resonance images at 9 and 51 days after the poisoning showed bilateral elevation of signals in the caudate nuclei and the putamina. At the 143th and 286th days. T2-weighted high-resonance areas were restricted to the lateral portion of the putamina. The T1-weighted images at the 51st day showed abnormal signal elevations in both putamina, while those of 9th, 143th and 286th days were mainly normal. Selective vulnerability of the putamen and the caudate nucleus may be due to their specific structural properties of high oxygen and glucose utilization, and enzyme distribution. Both chronological changes of striatal damage and the absence of neurological sequelae in this patient suggest the possibility that anti-epileptics and a calcium antagonist played a neuroprotective role in the acute cyanide intoxication.

Adult↗

PubMed1993

Mechanism of induction of Bar-like eye malformation by transient overexpression of Bar homeobox genes in Drosophila melanogaster.

The Bar locus of Drosophila is known to be a small complex consisting of two similar homeobox genes, BarH1 and BarH2. Using egr as an ommatidium marker, possible mechanisms of formation of malformed eyes were examined. As in the case of BarH1, overexpression of BarH2 was found to be capable of inducing Bar-like eye malformation. It was suggested that suppression of the anterior progression of the morphogenetic furrow and inhibition of reinitiation of normal ommatidial differentiation were mandatory to formation of the reduced eye morphology in Bar mutants.

Animals↗

PubMed1993

Characteristics of the thiobarbituric acid reactivity of human urine as a possible consequence of lipid peroxidation.

A 532 nm red pigment formed in the thiobarbituric acid (TBA) assay of human urine was characterized after separation of the pigment by high-performance liquid chromatography. The yield of the red pigment was somewhat higher at pH 2 than at pH 5; its development was not inhibited by ethylenediaminetetraacetic acid. The characteristics of the pigment were similar to those of the pigment derived from standard malonaldehyde. The amount of the pigment formed was roughly equal to the content of malonaldehyde derivatives estimated as 1-(2,4-dinitrophenyl)pyrazole. Pigment formation was significantly enhanced by t-butyl hydroperoxide (t-BuOOH) and ferric ions, which may be due to pigment formed from aldehydes other than malonaldehyde; the presence of these aldehydes was confirmed by the formation of the corresponding 2,4-dinitrophenylhydrazones. The amount of pigment produced from 24-h urine samples of 12 healthy subjects was estimated to be 26-95 nmol/kg, and 65-182 nmol/kg in the presence of t-BuOOH. These values are lower than those for urine of rabbit or rat. The TBA reactivity in the absence and presence of t-BuOOH of human urine was not related to age or sex. The TBA reactivity of human urine collected in the afternoon and in the evening was higher than that of urine collected in the morning.

Animals↗