Biomedical subjects

T Ushijima

Publications and source records attributed to T Ushijima.

At least 109 records · Page 6Linked to original sources

PubMed1995

[Continuous measurement of myocardial oxygen saturation using near-infrared spectroscopy during warm blood cardioplegia].

Continuous infusion of warm blood cardioplegic solution is often interrupted during coronary artery bypass grafting to obtain a bloodless operating field. We measured myocardial oxygen saturation continuously using near-infrared spectroscopy to determine myocardial oxygen metabolism during intermittent warm blood cardioplegia (IWBC). In 7 adult mongrel dogs undergoing cardiopulmonary bypass IWBC was administered using the Buckberg-Shiley system. Cardiac arrest was induced by a warm blood cardioplegic infusion of 100 ml/min for 5 minutes followed by a maintenance infusion of 40 ml/min for 5 minutes. The infusion of warm blood cardioplegia was then stopped for 15 minutes. Measurement of myocardial oxygen saturation was performed continuously throughout cardiopulmonary bypass. IWBC produced an increase in myocardial oxygen saturation for the first 5 minutes and a slight decrease for the second 5 minutes. After the termination of IWBC, myocardial oxygen saturation showed a marked reduction for 3 minutes and plateaued after 5 minutes. Measurement of myocardial oxygen saturation revealed myocardial oxygen metabolism during IWBC. This procedure may be a useful way to monitor myocardial oxygen metabolism during open heart surgery.

Animals↗

PubMed1995

[Surgical treatment of coronary artery fistulas].

Coronary artery fistula is one of the most common coronary malformations and is being diagnosed with increasing frequency with widespread use of selective coronary arteriography. Twenty-one patients with coronary artery fistulas underwent surgical treatment at our institute between 1973 and 1994. The left coronary artery was most commonly involved, and the fistula communicated primarily with the pulmonary artery. Associated cardiovascular disease include: mitral stenosis (1), mitral insufficiency (1), partial anomalous pulmonary venous return (1), ventricular tachycardia (1), atrial septal defect (1), aortitis syndrome (1), and coronary arteriosclerotic narrowing (1). In five patients, the coronary artery fistulas were selectively ligated without CPB. In sixteen patients, in addition to selective ligation, the fistula ostia were closed from inside using CPB. There were no operative or late deaths in the patients who underwent operations. Thus, the risks of surgical correction appear to be considerably less than the potential development of serious and possibly fatal complications, even in asymptomatic patients.

Adult↗

PubMed1995

[Left ventricular systolic and diastolic function after mitral valve replacement with preservation of posterior chordae tendineae].

Left ventricular function was compared in 14 patients who underwent mitral valve replacement with preservation of the posterior leaflet, chordae tendineae and papillary muscle (preserved group) and 14 patients who underwent conventional mitral valve replacement (non-preserved group). 99mTc radionuclide ventriculography was performed before surgery and one month after surgery. The early diastolic filling rate, an indicator of the efficiency of diastolic function, was measured. The patients in the non-preserved group showed an anteroseptal ejection fraction of 28 +/- 10% before surgery and 32 +/- 10% after surgery, an apical ejection fraction (71 +/- 10% vs 73 +/- 16%), and an inferolateral ejection fraction (56 +/- 16% vs 53 +/- 16%). The global ejection fraction tended to decrease from 56 +/- 9% to 52 +/- 10%. The patients in the preserved group showed an anteroseptal ejection fraction of 37 +/- 13% before surgery and 43 +/- 19% after surgery, an apical ejection fraction (74 +/- 20% vs 77 +/- 17%) and an inferolateral ejection fraction (53 +/- 11% vs 68 +/- 16%). The global ejection fraction, reflecting improvement in the inferolateral ejection fraction, tended to increase from 53 +/- 11% to 58 +/- 11%. The early diastolic filling rate for the preserved group was 1.73 +/- 0.43 before surgery and 1.05 +/- 0.61 after surgery, while that for the nonpreserved group was 1.59 +/- 0.24 vs 0.97 +/- 0.48. Although the early diastolic filling rate normalized in both groups, there was no significant difference between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Chordae Tendineae↗

PubMed1995

[Familial breast cancer].

Japanese breast cancer families were collected and classified into the following 7 types according to the onset age and the distribution of other cancers in the family lines; early-onset type, late-onset type, familial breast-ovarian cancer type, familial breast-prostate cancer type, familial breast-thyroid cancer type, familial male and female breast cancer type and multiple primary cancer type. We have detected no p53 germ line mutations in the patients from these families. Linkage with BRCA1 was not detected in any single families. These data indicate that neither BRCA1 or p53 is a major susceptible gene in Japanese familial breast cancer. However, in the two site-specific breast cancer families, the same nonsense mutation of the BRCA1 gene was detected.

Age of Onset↗

PubMed1995

[Effect of tepid cardiopulmonary bypass in coronary artery bypass operation].

The effect of systemic temperature during cardiopulmonary bypass (CPB) surgery was evaluated in 100 patients. The patients were divided into three groups, based on systemic temperature during CPB; 28 degrees C, 30 degrees C, or 32 degrees C (tepid). Multidose cold crystalloid cardioplegia was administered for myocardial protection. Pump flow was maintained at 75 ml/kg/min. Methoxamine hydrochloride and phenothiazine were used to maintain systemic perfusion pressures between 60 and 80 mmHg. Preoperatively, there were no differences between groups in left ventricular ejection fraction or extent of coronary artery disease. The time required for CPB and weaning from CPB were significantly shorter in the 32 degrees C group than in either the 28 degrees C or the 30 degrees C group. There were significant differences in the doses of methoxamine hydrochloride and phenothiazine required in each group. Postoperatively, there were no significant differences in the incidence of myocardial infarction, stroke, or 30-day mortality between groups. In conclusion, tepid systemic perfusion shortens the length of CPB and does not differ significantly from cold perfusion with respect to mortality and morbidity.

Aged↗

PubMed1995

Genetic alterations in HCA-induced tumors.

Accumulating evidence from molecular oncology indicates that carcinogens may induce tumors through characteristic mutations in characteristic genes for each agent. Identification of specific mutations induced by heterocyclic amines (HCAs), food-borne carcinogens, should facilitate risk assessment of HCAs in man. Identification of characteristic genes affected by HCAs will lead to identification of the genes involved in human carcinogenesis. We therefore examined tumors induced by various HCAs from these two viewpoints. With regard to forestomach tumors induced in CDF1 mice by 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), mutations of Ha-ras and p53 were observed in four of eight and two of four tumors, respectively. One papilloma examined had mutations in both Ha-ras and p53, whereas two carcinomas had only one or the other. For Zymbal gland tumors induced in F344 rats by IQ, mutations of Ha- or Ki-ras were observed in both of two papillomas and in 10 of 13 squamous cell carcinomas (SCCs), while p53 mutations were limited to only four of the SCCs. The ras mutation was thus suggested to be an early event, while p53 mutation was more associated with malignancy. In liver tumors induced in F344 rats by 2-amino-3,8-dimethylimidazo[4, 5-f]quinoxaline (MeIQx), mutations of p53 were observed in one of two moderately-differentiated and two of two poorly-differentiated hepatocellular carcinomas (HCCs). No such changes were found in any of nine well-differentiated HCCs, suggesting p53 mutation to be a very late event. In colon tumors induced in F344 rats by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (nine adenocarcinomas), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (two adenomas and nine adenocarcinomas), or 2-amino-6-methyldipyrido[1,2-a:3', 2'-d]imidazole (Glu-P-1) (seven adenocarcinomas), a Ki-ras mutation was found in only one Glu-P-1-induced adenocarcinoma. No p53 mutations could be detected. In mammary gland carcinomas induced in F344 rats by PhIP, Ha-ras was activated in three of 17 carcinomas and p53 was mutated in one of 10 carcinomas. We therefore concluded that other genes were involved in colon and mammary carcinomas. G:C base pairs were involved in all 42 positive cases of the present study, and 36 of them were guanine base mutations. This indicates that the changes in IQ, MeIQx, PhIP and Glu-P-1 tumors were mainly caused by non-transcribed strand modifications through their major DNA adducts, N2-(guanin-8-yl)HCAs. Ha-ras mutations in the forestomach tumors induced by MeIQ were all G to T transversions at the second position of codon 13. Mutation sites of p53 did not appear to be specific in the forestomach, Zymbal gland and liver tumors.

Animals↗

PubMed1994

Bilateral Breast Cancer in a Patient with a Strong Family History of Cancer: Analysis of p53 Germ Line Mutations.

We report a case of bilateral breast carcinoma in a patient with a strong family history, including 4 cases of breast carcinoma, 1 case of prostate carcinoma (father), 1 case of hepatocellular carcinoma (mother), 2 cases of gastric carcinoma, 1 case of lung carcinoma, and 1 case of lingual carcinoma, in second degree relatives, together with analysis of germ line p53 mutations. The patient was a 51-year-old female who had undergone mastectomy 9 years previously for an invasive ductal carcinoma of the right breast. Lymph nodes were free of metastases and the tumor had negative estrogen receptor (ER) status. Bone and lung metastases developed 18 months after surgery, and had been well controlled with chemoendocrine therapy. She subsequently underwent a modified radical mastectomy for carcinoma in the contralateral breast. This was an invasive lobular carcinoma with negative lymph node metastasis, negative p53 immunoreaction, negative c-erbB-2 protein and positive ER status. In this breast-prostate carcinoma-type cancer family there was a high incidence of breast carcinoma; the father, who had prostate carcinoma, was possibly a carrier of a breast carcinoma susceptible gene. We have however detected to p53 germ line mutations in the lymphocytes DNA of the patient and her niece. The accumulation of cancers in this family line remains to be elucidated further using other genetic markers.

Journal Article↗

PubMed1994

Instability of microsatellites in rat colon tumors induced by heterocyclic amines.

Microsatellite instability in rat colon tumors induced by heterocyclic amines was examined by studies on the lengths of 85 microsatellite sequences, covering most of the rat chromosomes in tumors and normal tissues. Seven of eight colon tumors induced by 2-amino-1-methyl-6- phenylimidazo-[4,5-b]pyridine showed alterations at least at one locus of microsatellite sequences, whereas no mutations were observed in colon tumors induced by 2-amino-3-methylimidazo[4,5-f]quinoline. Three 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine-induced colon tumors had mutations in more than one microsatellite, their mutation rates being 2 of 85, 2 of 85, and 3 of 85 allele/mircrosatellite sequence, respectively. These data suggest that rat colon adenocarcinomas induced by 2-amino-1-methyl-6- phenylimidazo-[4,5-b]pyridine but not 2-amino-3-methylimidazo[4,5-f] quinoline show a trait of microsatellite instability. This is the first systematic study of microsatellite instability in experimental animal models of carcinogenesis.

Animals↗

PubMed1994

Dietary carcinogens and mammary carcinogenesis. Induction of rat mammary carcinomas by administration of heterocyclic amines in cooked foods.

Grilled or fried meat and fish contain various mutagenic heterocyclic amines, and structures of at least 19 compounds have already been determined. Among these, 10 have been examined for long term carcinogenicity, all proving to be positive. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), for example, preferentially induced mammary adenocarcinomas in 47% of Fischer 344 female rats when supplemented into the diet at a concentration of 400 parts per million (ppm) for 52 weeks. Moreover, 100 ppm of PhIP for 104 weeks yielded the same incidence. PhIP in the diet for 48 weeks also induced mammary cancer in Sprague-Dawley female rats with incidences of 72 and 25% at 200 ppm and 100 ppm. 2-Amino-3,4-dimethylimidazo[4,5-f]quinoline in the diet at 300 ppm also induced a 25% incidence of mammary adenocarcinomas within 40 weeks. Analysis of PhIP-induced rat mammary carcinomas for ras mutations by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing revealed Ha-ras activation in 3 of 17 carcinomas; all were G-->A transitions at the second letter of codon 12 replacing glycine by glutamic acid. A p53 gene mutation was also found in 1 of 10 carcinomas examined; a G-->T transversion was detected at the third letter of codon 130, with a substitution of asparagine for lysine. PhIP is the most abundant mutagenic and carcinogenic heterocyclic amine in grilled meat, and, therefore, a role for this compound in human carcinogenesis is strongly implied.

Adenocarcinoma↗

PubMed1994

Cloning and activation of the Syrian hamster neu proto-oncogene.

Point mutations of the Syrian hamster neu proto-oncogene have been observed in the transmembrane domain of N-nitroso-N-ethylurea (ENU)-induced neurofibromas. Genomic DNA derived from tumor tissue showed transforming activity in an NIH 3T3 assay and a cDNA clone of the hamster neu gene, containing the entire protein-coding region, was isolated from a transformant cDNA library. The encoded product is 92 and 88% homologous to the rat neu and the human c-erbB-2, respectively. The product of the mutated hamster neu gene showed increased autophosphorylation of Tyr residues.

3T3 Cells↗

PubMed1994

neu proto-oncogene mutation is specific for the neurofibromas in a N-nitroso-N-ethylurea-induced hamster neurofibromatosis model but not for hamster melanomas and human Schwann cell tumors.

Point mutations of the transmembrane domain coding region of the neu proto-oncogene in N-nitroso-N-ethylurea-induced hamster neurofibromas were found at high frequency (93%; 14 of 15). They involved codons 659 as well as 658, the latter not having been reported previously in rat tumors. The mutational change was seen even in the early stage neurofibroma. On the other hand, no mutations were detected in melanomas or Wilms' tumors induced in the same N-nitroso-N-ethylurea-treated animals, even when the melanomas demonstrated extensive schwannian differentiation. Moreover, any human Schwann cell tumors including neurofibroma, schwannoma, and malignant schwannoma did not show the mutation of c-erbB-2 gene (0 of 34), which is homologous to the hamster neu. Since high expression of neu mRNA is evident in the hamster Schwann cell at the late gestational and neonatal stages, transplacental administration of N-nitroso-N-ethylurea is considered to interact directly to carcinogenesis of the hamster Schwann cell through neu gene mutation.

Amino Acid Sequence↗

PubMed1994

Infrequent mutation of Ha-ras and p53 in rat mammary carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundant of the heterocyclic amines, a group of potent carcinogens contained in cooked meat and fish. Female F344 rats fed a diet containing 100 or 400 ppm PhIP developed mammary carcinomas within 104 or 52 wk, respectively, at the rate of 47% for each group; these carcinomas were examined for mutations in three members of the ras gene family and in the p53 gene. Single-strand conformation polymorphism (SSCP) analysis and direct sequencing demonstrated a G-->A transition at the second position of Ha-ras codon 12, with the resultant substitution of glutamic acid for glycine, in two of 10 carcinomas induced by 100 ppm PhIP and in one of seven induced by the 400 ppm dose. No mutations in Ki-ras or N-ras were detected. cDNA polymerase chain reaction-SSCP analysis and direct sequencing demonstrated a G-->T transversion at the third position of p53 codon 130, with the resultant substitution of asparagine for lysine, in one of the 10 carcinomas induced by 100 ppm of PhIP for which freshly frozen samples were available. PhIP-induced rat mammary carcinogenesis can be regarded as a unique system in that rat mammary carcinomas are negative for ras and p53 mutations.

Animals↗

PubMed1994

Mutations in the COL4A5 gene in Alport syndrome: a possible mutation in primordial germ cells.

Using a combination of gene amplification with single strand conformation polymorphisms analysis and sequencing, we examined the COL4A5 gene in 37 patients with Alport syndrome. In patient A8, a single base insertion was noted at codon 1,597 tyrosine in exon 49. The premature terminal signal appeared and 89 amino acids (approximately one-third) of the non-collagenous domain were lost. The mutation was present in the mother, hence she is heterozygous. In patient A12, the nucleotide changed from C to T at codon 1,679 glutamine in exon 51, which created a termination codon, and 7 amino acids at the carboxyl terminus were lost. Gene tracking using peripheral leukocytes revealed that the parents did not carry the mutant allele, while the sister was heterozygous. DNA samples from hair roots and skin fibroblasts of the mother were normal and immunological examination of the epidermis of the mother indicated that the alpha 5(IV) chain was normally expressed. As these results suggest that somatic cells of the mother do not carry the mutant allele, the primordial germ cells possibly carry a fresh mutation in the mother of patient A12.

Adolescent↗

PubMed1994

Tissue-specific mutational spectra of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline in the liver and bone marrow of lacI transgenic mice.

2-Amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) is a food-borne heterocyclic amine, so clarification of its mutational spectrum is important for evaluation of its carcinogenic risk to humans. The mutational spectrum of MeIQ was investigated in the liver and bone marrow of transgenic mice carrying the lacI gene. By PCR--single-strand conformation polymorphism analysis and sequencing of the lacI gene, 81 and 61 mutations were identified in 80 and 59 mutants obtained from the liver and bone marrow respectively of three transgenic mice given food containing 300 p.p.m. MeIQ. In the liver, G-->T transversions were the most frequent, accounting for 46% of the total mutations, followed by G-->A transitions (25%). In the bone marrow, four types of mutations, G-->T transversions, G-->A transitions, complex mutations and one base deletions, each accounted for 21-23% of the total mutations. Of the total mutations, 10% were found at nucleotide 92 in the liver and at nucleotide 222 in the bone marrow. Analysis of 27 and 13 mutants from the liver and bone marrow respectively of control mice showed frequent G-->A transitions at CpG sites. These findings suggest a tissue-specific mechanism of mutagenesis.

Animals↗

PubMed1994

Presence of p53 mutations in 3Y1-B clone 1-6: a rat cell line widely used as a normal immortalized fibroblast.

The 3Y1 cell line, established from a rat whole embryo, is widely used as a normal immortalized fibroblast. We analyzed p53 mutations in four clonal lines derived from the 3Y1 cell line; 3Y1-B clone 1-6, 3Y1-C and two clonal lines (3Y1 cl-3 and 3Y1 cl-6) which had been transformed by the human papilloma virus E6 gene. Polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis and DNA sequencing showed that three clonal lines had a double mutation at codons 130 and 136 on the same allele and that the other clonal line, 3Y1 cl-3, had no mutations. 3Y1-B clone 1-6, which has been registered as the standard clonal line at the Japanese Cancer Research Resources Bank, demonstrated weak bands of the wild type allele, suggesting the existence of heterogeneous cell types in this "clonal" line. PCR-SSCP analysis of 25 subclones obtained by limiting dilution of 3Y1-B clone 1-6 cells revealed a mixture of two types of cells; 12 subclones showed only the bands of mutated allele, and 13 subclones showed both bands of the wild and mutated p53 alleles. These findings should be taken into consideration when using this cell line as a normal immortalized cell line.

Animals↗

PubMed1994

Absence of p53 mutations in rat colon tumors induced by 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole, 2-amino-3-methylimidazo[4,5-f]quinoline, or 2-amino-1-methyl-6-phenylimidazo]4,5-b]pyridine.

Colon tumors were induced in F344 rats by three heterocyclic amines (HCAs), 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and examined for p53 mutations. Seven carcinomas induced by Glu-P-1, and nine carcinomas and two adenomas induced by IQ were examined by cDNA-polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis from codon 103 to 391 of p53, which encompasses the conserved regions II to IV. Nine carcinomas induced by PhIP were examined by genomic PCR-SSCP analysis of exons 5 to 7 (from codon 124 to 304), which encompasses the 3' half of the conserved region II and all the conserved regions III-V. No band shifts were found in any of these tumors under at least two conditions of SSCP analysis. Our previous study had shown a Ki-ras mutation in only one Glu-P-1-induced adenocarcinoma among the same 27 colon tumors, and no other mutation of ras family genes had been found. HCA-induced rat colon tumors appear to represent a group of human colon tumors in which neither Ki-ras nor p53 is involved.

Adenocarcinoma↗

PubMed1994

Linkage analysis of BRCA1 in Japanese breast cancer families.

We examined the involvement of BRCA1, which plays a major role in Western breast cancer families, in Japanese breast cancer families. Eleven families, in which at least three individuals within third degree relatives were affected by breast cancer, were collected. Five of them were early-onset breast cancer families, in which the average age at diagnosis was less than 45 years, and the other six were late-onset families. Ovarian cancer was observed in one patient in the early-onset families. Using seven polymorphic markers on chromosome 17q21, D17S250, ERBB2, THRA1, D17S579, D17S588, GIP and NME1, linkage to BRCA1 was analyzed. Linkage was not detected in any single family. Assuming homogeneity in an inherited component that confines the susceptibility to breast cancer in all families, we summed the LOD scores of all families. The cumulative LOD score obtained was -1.86 for D17S588 at theta = 0.001, indicating no linkage with BRCA1. Since the proportion of families linked to BRCA1 is larger in Western early-onset breast cancer families than in late-onset ones, we also summed the LOD scores of five early-onset families. However, again a negative LOD score was obtained. These results suggest that BRCA1 is not a major breast cancer susceptibility gene in Japanese familial breast cancer.

Adult↗

PubMed1994

p53 gene mutations in human prostate cancers in Japan: different mutation spectra between Japan and western countries.

The involvement of p53 mutations in prostate cancers in Japan was investigated. To evaluate any possible clinicopathological significance, p53 mutations in 40 samples from 36 Japanese prostate cancers of different stages (five cases of latent tumors, three of stage A cancers, 10 of stage B, five of stage C and 13 of stage D), including four lymph node metastases of stage D cases, were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and sequencing. Mutations were detected in five of 40 samples (12.5%); four were in primary cancers and the other in a lymph node metastasis from one of them. All mutation-positive cases were in stage D, and the mutation frequency in stage D cases was 31%. This result indicates that p53 mutations may play a role in the progression of a subgroup of prostate cancers in Japanese, as observed for Americans and Europeans. However, a difference was noted between Japanese and Americans in the p53 mutational spectrum (at CpG site), presumably arising from variation in the underlying etiologic factors.

Aged↗