Search PubMed⌕ Search

Biomedical subjects

T Ushijima

Publications and source records attributed to T Ushijima.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Quantitative hemodynamic assessment of internal thoracic artery grafts using transthoracic duplex imaging].

The hemodynamics of blood flow in internal thoracic artery (ITA) grafts were studied using transthoracic duplex imaging prior to and following coronary artery bypass grafting (CABG) in 37 patients. Transthoracic images of the ITA were obtained through the first intercostal space using a 7.5 MHz probe, and their diameter and area were measured by B-mode imaging. Systolic, diastolic, mean and end-diastolic blood flow velocity (Vs, Vd, Vm, and Ved) were determined based on Doppler signals and systolic, diastolic, and total blood flow (Fs, Fd, and Ftotal) were calculated by the following formula: Flow = Vm x area x 60/10(3). The diameter of the ITA increased following CABG. Prior to CABG, Vs, and Fs, were dominant, while following CABG, the hemodynamic pattern was diastolic dominant, although individual variation existed. The ITA blood flow was measured in 4 groups, in patients who had had a previous anterior myocardial infarction and no redistribution on myocardial scintigraphy (group I), in patients with 99-100% coronary artery stenosis who had not had an anterior myocardial infarction or who had an anterior myocardial infarction and had redistribution (group IIa), in patients with the same criteria as group IIa but who had 90% coronary stenosis (group IIb), and in patients with 75% coronary stenosis who had not had anterior myocardial infarction (group IIc). Blood flow was 57, 73, 44mL and 34 mL/min, and the percentage of diastolic flow was 72, 69, 61, 59% respectively. These results show that ITA blood flow competes with native coronary artery flow in patients with moderate coronary stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Rare frequency of activation of the Ki-ras gene in rat colon tumors induced by heterocyclic amines: possible alternative mechanisms of human colon carcinogenesis.

Heterocyclic amines present in cooked foods are known to produce colon tumors in F344 rats at a high incidence, indicating the possibility of involvement of ras gene activation in colon carcinogenesis in rats as in humans. We examined mutations at codons 12, 13, and 61 of the Ki-ras, Ha-ras, and N-ras genes by polymerase chain reaction--direct sequencing in seven colon tumors in F344 rats induced by 2-amino-6-methyldipyrido-[1,2-a:3',2'-d]imidazole (Glu-P-1), 11 induced by 2-amino-3-methylimidazo[4,5-f]quinoline, and nine induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine. A Ki-ras gene mutation (G-->T at the second position in codon 12) was found in one Glu-P-1-induced colon adenocarcinoma. None of the other 26 tumors had mutations in any of these three ras family genes. These results indicate that in rats, colon carcinogenesis induced by heterocyclic amines may be induced by alterations of other oncogenes or tumor suppressor genes. We think this experimental system using carcinogens to which humans are exposed is a good model for studying alterations of other genes in human colon tumors in which no Ki-ras alterations are observed.

Adenocarcinoma↗
PubMed1993

Involvement of RET oncogene in human tumours: specificity of RET activation to thyroid tumours.

Non-thyroid neoplasia were analysed by Southern blot of genomic DNA and DNA prepared by reverse transcription and amplification by polymerase chain reaction (RT/PCR) for the activation of the RET oncogene. It is known that the rearrangement of RET occurs in about 10%-20% of human thyroid papillary carcinomas. None of 528 non-thyroid tumours showed rearrangement of the RET proto-oncogene, whereas three out of 30 thyroid papillary carcinomas were positive for RET activation. Therefore the activation of RET seems to be a somatic cell mutation specific to human thyroid carcinomas.

Base Sequence↗
PubMed1992

Absence of ras family point mutations at codons 12, 13 and 61 in N-ethyl-N-hydroxyethylnitrosamine- or N-nitrosomorpholine-induced renal cell tumors in rats.

The prevalence of Ki-ras, Ha-ras and N-ras point mutation within exons 1 and 2 was studied in 17 cases of renal cell tumors (8 carcinomas and 9 adenomas) induced by N-ethyl-N-hydroxyethyl-nitrosamine or N-nitrosomorpholine. DNA samples prepared from acetone-fixed, paraffin-embedded tissues were amplified by means of the polymerase chain reaction, and point mutations at codons 12, 13 and 61 were analyzed by direct sequence methods with oligonucleotide primers. No mutations were detected in any of the renal tumors. The results thus indicated that ras family point mutation is not necessary for kidney tumor development in rats, supporting the view that ras mutations may not be generally relevant to neoplastic development in various organs in different species.

Adenoma↗
PubMed1992

[Clinicopathological survey of persistent hypocomplementemic glomerulonephritis in children; correlation of DPGN and MPGN type I].

We studied clinicopathologically 19 patients with abnormal urinary findings accompanying with persistent hypocomplementemia under age 15. They consisted of 6 patients with membranoproliferative glomerulonephritis (MPGN) type I, 2 with MPGN type II, 2 with focal MPGN, 8 with diffuse proliferative glomerulonephritis (DPGN), 1 with focal glomerulonephritis (FGN). 17 cases were treated with steroid. In 2 patients with MPGN type I and 1 patient with DPGN, the treatment resulted in normalization of serum C3 level and urinary abnormalities and improvement of histological findings. In 3 patients with DPGN, urinary abnormalities and hypocomplementemia have been persisted and histological findings changed to those of MPGN type I. Thus, DPGN with hypocomplementemia seems to be an early stage of MPGN type I.

Adolescent↗
PubMed1991

A high phosphorylation state and increased activity of the TRE motif in the NIH3T3 cell transformant induced by retTPC.

A 57 kDa protein was detected in an NIH3T3 transformant induced by retTPC, an activated form of the ret proto-oncogene which encodes a receptor-tyrosine kinase. A high phosphorylation state and increased activity of a TPA responsive element was observed in the transformant. Increased expression of c-jun mRNA was also detected. A 40 kDa protein in the retTPC transformant, which was specifically immunoprecipitable with v-jun antiserum, was highly phosphorylated mainly at a serine residue(s). These data suggest that an aberrant signal triggered by a retTPC product affects the cellular serine/threonine phosphorylation state resulting in high phosphorylation of c-jun protein.

Animals↗
PubMed1991

Selected faecal bacteria and nutrients essential for antagonism of Salmonella typhimurium in anaerobic continuous flow cultures.

As few as five of the species of bacteria commonly found in human faeces--Escherichia coli, Enterobacter aerogenes, Enterococcus faecalis, Bacteroides ovatus and Fusobacterium varium--when grown together in anaerobic continuous flow cultures exerted antagonistic effects on Salmonella typhimurium as great as those given by mixed bacteria from extracts of human faeces. In a single culture, the population of S. typhimurium was c. 10(8) cfu/ml but in mixed cultures with the five antagonistic bacteria or mixed faecal bacteria it was reduced to c. 10(3) cfu/ml. Antagonism appeared to be the result of competition for the growth limiting amino acids, arginine, serine, threonine and aspartic acid. Optimal manifestation of antagonism required the presence of carbon sources fermentable only by antagonistic bacteria, such as lactose 0.1%, w/v, sucrose 0.1% (w/v) and starch 0.2-0.3% w/v. These carbohydrates promoted the growth of the antagonistic bacteria, particularly E. coli and B. ovatus. However, an increase in concentration by several fold of any one of four growth-limiting amino acids in the medium diminished the antagonistic effects and the population of S. typhimurium rose 10(2)-10(3)-fold.

Amino Acids↗
PubMed1991

Effects of subminimal inhibitory concentrations of erythromycin, tetracycline, clindamycin, and minocycline on the neutrophil chemotactic factor production in Propionibacterium acnes biotypes 1-5.

Biotypes 1-5 Propionibacterium acnes (P. acnes) strains were grown in the presence of 1/10 minimal inhibitory concentrations (sub-MIC) of erythromycin (EM), tetracycline (TC), clindamycin (CLDM), or minocycline (MINO) and their culture filtrates were assayed for human neutrophil chemotactic activity using Boyden chamber methods. The addition of sub-MIC of MINO to the medium strongly suppressed the neutrophil chemotactic activity of the culture filtrates of P. acnes strains of all biotypes. In contrast, with sub-MIC of EM, TC, or CLDM, the activity of the culture filtrates of P. acnes strains of biotypes 2 and 3 were suppressed but those of biotypes 1, 2, and 5 were not. These results indicate that sub-MIC of MINO is capable of decreasing the inflammatory capacity of P. acnes strains of all biotypes.

Acne Vulgaris↗
PubMed1991

Ki-ras activation in pancreatic carcinomas of Syrian hamsters induced by N-nitrosobis(2-hydroxypropyl)amine.

Five pancreatic carcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in Syrian golden hamsters were analyzed for activation of Ki-ras at codons 12 and 13, using the polymerase chain reaction and direct sequencing. The Ki-ras gene was shown to be activated in four of the five carcinomas, and the results were further confirmed by subcloning and sequencing. All the mutations involved a G-to-A transition at the second position of codon 12, which resulted in a change at the amino acid level from glycine to aspartic acid. This mutation is identical with that reported for pancreatic tumors of Syrian hamsters induced by N-nitrosobis(2-oxopropyl)amine.

Animals↗
PubMed1991

Detection of retTPC/PTC transcripts in thyroid adenomas and adenomatous goiter by an RT-PCR method.

A reverse transcriptase-polymerase chain reaction (RT-PCR) method was adopted for detecting transcripts specific for retTPC/PTC, an activated form of the ret proto-oncogene reported to be found specifically in human papillary thyroid carcinomas. By this sensitive method retTPC/PTC transcript could be detected in about 500 fg of total RNA of TPC-1, a retTPC/PTC transcript-positive cell line. In Japanese patients, one of 11 papillary thyroid carcinomas, four of 19 follicular adenomas and one of two adenomatous goiters were positive for the transcript, indicating that the involvement of retTPC/PTC is not specific to papillary thyroid carcinomas. In several independent RT-PCR experiments using different portions of the same positive carcinoma tissue, retTPC/PTC transcript was always detected. On the other hand, the transcript was not always positive in different RNA samples from benign cases, suggesting that positive carcinomas are probably composed of clonal cell populations all expressing retTPC/PTC, whereas adenomas and adenomatous goiter comprise heterogeneous populations: both positive and negative for retTPC/PTC transcript. Activation of the ret proto-oncogene might therefore be involved in malignant conversion to thyroid carcinomas.

3T3 Cells↗
PubMed1991

[The influence of exercise loading for a long period on the renal function of the children with mesangial proliferative glomerulonephritis].

We have studied the influence of exercise on renal function in chronic glomerulonephritis with mesangial proliferation. The mesangial proliferative glomerulonephritis consisted of (1) IgA nephropathy (Mild group), (2) IgA nephropathy (Moderate group), (3) diffuse proliferative glomerulonephritis = DPGN (Mild group), were divided 2 groups between (A) exercise loading groups and (B) control groups, respectively. The period of observation was one or one year 6 months. None of cases deteriorated in the renal function during the period of observation were found in the exercise loading groups. The prescription of exercise for permits with mesangial proliferative glomerulonephritis indicates approximately 130 values of %BMR, which is estimated by calorie counter.

Adolescent↗
PubMed1990

cDNA cloning and characterization of ret activated in a human papillary thyroid carcinoma cell line.

We obtained activated ret cDNAs (retTPC) from a human papillary thyroid carcinoma cell line, TPC-1, and characterized its structure. The nucleotide sequence indicated that the recombination had occurred just upstream of the kinase domain of ret proto-oncogene and that the position, where the conserved sequence of ret proto-oncogene starts in retTPC transcripts, was exactly the same as that of ret-II which we have previously analyzed. Furthermore, a unique 13-glycine stretch, which is also present in a small subunit of the calcium dependent protease, calpain, was detected in the replaced sequence of retTPC. The aberrant tyrosine kinase activity induced by the rearrangement of ret proto-oncogene could be involved in the development of papillary thyroid carcinoma.

Amino Acid Sequence↗
PubMed1990

The inhibition of free radical generation by human neutrophils through the synergistic effects of metronidazole with palmitoleic acid: a possible mechanism of action of metronidazole in rosacea and acne.

Metronidazole is clinically effective in treating not only rosacea but also acne inflammation. Yet it is generally considered not to be very effective in inhibiting the growth of anaerobic Propionibacterium acnes. We report here our investigation into the synergistic effects of metronidazole and palmitoleic acid on the anaerobic growth of P. acnes as well as on human neutrophil functions, including the generation of reactive oxygen species (ROS). Both metronidazole and palmitoleic acid, when used alone, only slightly inhibited the growth of P. acnes, and no significant decrease in human neutrophil functions, including the generation of ROS, was observed. But metronidazole used in the presence of palmitoleic acid markedly inhibited the anaerobic growth of P. acnes and decreased ROS generation by neutrophils. However, ROS generated in the xanthine-xanthine oxidase system were not affected. Metronidazole was shown to be clinically effective by decreasing neutrophil-generated ROS at the sites of inflammation with the aid of palmitoleic acid, which is generally present in human skin. By inhibiting oxidative tissue injury under in vivo conditions, treatment with metronidazole results in remarkable improvement of rosacea and acne.

Acne Vulgaris↗
PubMed1990

Transposon insertion mutagenesis of a genetic region encoding serum resistance in an 80 kb plasmid of Salmonella dublin.

Using transposon insertion mutagenesis with Tn1 or Tn5, we obtained Salmonella dublin mutant strains that showed either diminished serum resistance (five mutants) or diminished mouse lethality (two mutants). Detailed restriction cleavage analysis to determine the single sites of transposon insertion in an 80 kb plasmid (pTE800) indicated that a region for serum resistance was located within a 3.0 kb region of the SalI cleavage fragment 5 and the HindIII fragment 2, while the region for mouse lethality was within a 6.0 kb region of the SalI fragment 2 and the HindIII fragment 1. When the Tn1-containing SalI fragment 5 was reconverted, by homologous recombination, to the original SalI fragment 5 (9.6 kb), serum resistance was recovered to the same level as that of a parent strain 52401. Moreover, the change in the serum resistance correlated with changes in the neutral sugar composition of the LPS. The mutation in the plasmid in strain TE4-55 that gave diminished mouse lethality was also reversed by recombination with the cloned SalI fragment 2 (15.0 kb), with concomitant recovery of mouse lethality. These results indicate that the genetic region for serum resistance is different from that for mouse lethality, and that the gene for serum resistance is closely involved with the expression of the neutral sugar composition of the LPS of S. dublin.

Animals↗
PubMed1990

Comparison of host responses induced by Salmonella typhimurium infection in genetically resistant and susceptible mice.

A/J and BALB/c mice differ genetically in their resistance to the facultative intracellular bacterium Salmonella typhimurium. We compared the responses of these strains of mice to a virulent S. typhimurium infection. BALB/c mice mobilised more peritoneal exudate cells in response to the infection than did A/J mice 30 h after infection, but the increase in bacterial counts in the livers and spleens of BALB/c mice was 10-fold higher than in A/J mice. The response to Concanavalin A (Con A) of spleen cells from BALB/c mice was depressed, and both L3T4+ and Lyt-2+ T cell subpopulations were decreased following the infection, whereas the response to Con A of A/J mice was increased and the T cell subpopulations were not altered significantly. These results suggest that A/J mice respond more actively to S. typhimurium infection than do BALB/c mice, and this may be related to the natural resistance of mice.

Animals↗
PubMed1990

The role of Escherichia coli haemolysin in the pathogenic synergy of colonic bacteria in subcutaneous abscess formation in mice.

The growth of nine species of colonic bacteria--Escherichia coli, Enterococcus faecalis, Bacteroides ovatus, Fusobacterium varium, Clostridium perfringens, Klebsiella pneumoniae, Proteus vulgaris, Staphylococcus aureus and Bifidobacterium adolescentis--was examined after concomitant injection to form experimental subcutaneous abscesses in mice. Injection of a mixture of c. 10(5) cfu of each of the first five strains (E. coli, Ent. faecalis, B. ovatis, F. varium and C. perfringens) resulted in abscess formation in all mice tested when the E. coli strain was haemolytic. E. coli and B. ovatus multiplied and reached a maximum population of c. 10(8) cfu/abscess. When non-haemolytic E. coli was used, injection of greater than or equal to 10(7) cfu was required for abscess formation. The inclusion of partially purified E. coli haemolysin (125 HU50) with c. 10(5) cfu of bacteria including non-haemolytic E. coli resulted in abscess formation in most mice tested. These results indicate that E. coli haemolysin is one factor that may potentiate pathogenic synergy among colonic bacteria especially between E. coli and B. ovatus, during abscess formation.

Abscess↗
PubMed1990

Chronic nephritis, sensorineural deafness, growth and developmental retardation, hyperkinesis, and cleft soft palate in a 5-year-old boy. A new combination?

A 5-year-old Japanese boy showed nephritis similar to, but distinct from, that in Alport syndrome. Nephrotic syndrome without hematuria was noticed at age 2, although renal biopsy at age 4 revealed widespread irregular thickening of the glomerular basement membrane with splitting of the lamina densa on electron microscopy, characteristic of nephritis in Alport syndrome. Sensorineural deafness was noticed at age 4 weeks by no auditory brain stem response, unusually early for Alport syndrome. Goodpasture antigen and amyloid P component were found in the glomerular basement membrane. Thus, the antigenicity of the glomerular basement membrane was different from that in male patients with X-linked Alport syndrome. In addition, growth and developmental retardation, hyperkinesis, and cleft soft palate were seen. These features are a hitherto undescribed combination. The family history was negative for any of the features of the boy.

Child, Preschool↗