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Biomedical subjects

Y Murakami

Publications and source records attributed to Y Murakami.

At least 757 records · Page 42Linked to original sources
PubMed1990

Monoclonal antibody studies on the properties and regulation of murine ornithine decarboxylase antizymes.

Seven monoclonal antibodies were prepared against rat liver ornithine decarboxylase antizyme, a unique regulatory protein of the enzyme induced by its products. The monoclonal antibodies reacted with antizymes from all the rat and mouse tissues examined, indicating that these antizymes share similar structural features, though some size heterogeneity has been reported for rat antizymes. A sandwich enzyme immunoassay which could detect 0.1 ng of antizyme was developed using these antibodies. The amount of antizyme protein in rat liver, analyzed by the immunoassay, increased on putrescine treatment in parallel with antizyme activity, indicating that the changes in antizyme activity were attributable to the changes in the amount of its protein. The putrescine-induced increase of antizyme protein, as well as that of its activity, was completely inhibited by cycloheximide but not by actinomycin D, confirming the importance of post-transcriptional regulation in antizyme induction.

Animals↗
PubMed1990

Analyses of ornithine decarboxylase antizyme mRNA with a cDNA cloned from rat liver.

Ornithine decarboxylase antizyme is a unique inhibitory protein induced by polyamines and involved in the regulation of ornithine decarboxylase. A cDNA was isolated from a rat liver cDNA library by the screening with monoclonal antibodies to rat liver antizyme as probes. The expression products of the cDNA in bacterial systems inhibited rat ornithine decarboxylase activity in a manner characteristic of antizyme and rabbit antisera raised against its direct expression product reacted to rat liver antizyme, confirming the authenticity of the cDNA. On RNA blot analysis with the cDNA probe, an antizyme mRNA band of 1.3 kb was detected in rat tissues. Antizyme mRNA did not increase upon administration of putrescine, an inducer of antizyme, and its half-life after actinomycin D treatment was as long as 12 h in rat liver, suggesting that antizyme mRNA is constitutively expressed and antizyme synthesis is regulated at the translational level. Similar-sized mRNAs hybridizable to the cDNA were also found in various mammalian and non-mammalian vertebrate tissues under physiological conditions. In addition, chicken and frog antizymes showed immunocrossreactivity with rat antizyme. The ubiquitous presence and the evolutionally conserved structure of antizyme in vertebrate tissues suggest that it has an important function.

Animals↗
PubMed1990

Purification of a mouse nuclear factor that binds to both the A and B cores of the polyomavirus enhancer.

We have previously identified a protein factor, PEBP2 (polyomavirus enhancer-binding protein), in the nuclear extract from mouse NIH 3T3 cells which binds to the sequence motif, PEA2, located within the polyomavirus enhancer A element. Upon cellular transformation with activated oncogene c-Ha-ras, this factor frequently undergoes drastic molecular modifications into an altered form having a considerably reduced molecular size. In this study, the altered form, PEBP3, was purified to near homogeneity. The purified PEBP3 comprised two sets of families of polypeptides, alpha-1 to alpha-4 and beta-1 to beta-2, which were 30 to 35 kilodaltons and 20 to 25 kilodaltons in size, respectively. Both kinds of polypeptides possessed DNA-binding activities with exactly the same sequence specificity. Individual alpha or beta polypeptides complexed with DNA showed faster gel mobilities than did PEBP3. However, the original gel retardation pattern was restored when alpha and beta polypeptides were mixed together in any arbitrary pair. These observation along with the results of UV- and chemical-cross-linking studies led us to conclude that PEBP3 is a heterodimer of alpha and beta subunits, potentially having a divalent DNA-binding activity. Furthermore, PEBP3 was found to bind a second, hitherto-unnoticed site of the polyomavirus enhancer that is located within the B element and coincides with the sequence previously known as the simian virus 40 enhancer core homology. From comparison of this and the original binding sites, the consensus sequence for PEBP3 was defined to be PuACCPuCA. These findings provided new insights into the biological significance of PEBP3 and PEBP2.

Animals↗
PubMed1990

Assembly of nascent DNA into nucleosome structures in simian virus 40 chromosomes by HeLa cell extract.

A soluble system was developed that could support DNA replication in simian virus 40 (SV40) chromosomes. DNA synthesis in this system required the presence of purified SV40 large tumor antigen, SV40 chromosomes prepared from virus-infected monkey cells, a crude extract from HeLa cells, and several low-molecular-weight components. In comparison to the replication of purified SV40 form I DNA, the rate of DNA synthesis was 15 to 20% in this system. DNA synthesis started near the replication origin of SV40 and proceeded bidirectionally in a semiconservative manner. Micrococcal nuclease digestion experiments revealed that the replicated DNA produced in this system became organized into a regularly spaced array of nucleosome core particles when an appropriate amount of purified HeLa core histones was added to the reaction mixture. SV40 form I DNA replicating under the same conditions was also assembled into nucleosomes, which were arranged in a rather dispersed manner and formed an aberrant chromatin structure.

Cell Line↗
PubMed1990

A polyomavirus enhancer-binding protein, PEBP5, responsive to 12-O-tetradecanoylphorbol-13-acetate but distinct from AP-1.

Element I, homologous to the adenovirus type 5 E1A enhancer core, is a 10-bp sequence in the A core of the polyomavirus enhancer and was shown previously to be responsive to 12-O-tetradecanoylphorbol-13-acetate (TPA). We found that element I by itself was capable of activating polyomavirus DNA replication in COP-5 cells which express the polyomavirus large T antigen. A nuclear factor, polyomavirus enhancer-binding protein 5 (PEBP5), which bound to the entire sequence of element I and was responsive to TPA was identified by an in vitro binding assay. Although the binding site of PEBP5 partly overlaps with that of PEBP1 (PEA1), a member of the AP-1 family, PEBP5 appears to be a distinct factor. Since we previously showed that element I alone was able to activate transcription, our present results suggest that PEBP5 is involved in the regulation of both transcription and replication of DNA. The amount of PEBP5 increased after F9 cells were induced to differentiate by retinoic acid. A relatively large amount of PEBP5 was detected in lymphoid and trophoblast cells.

Animals↗
PubMed1990

Immunohistochemical interpretation of early epithelial disorders of pyriform sinus.

Expression of cytokeratins (CKs) was investigated immunohistochemically by use of monospecific monoclonal anti-CK antibodies in normal epithelia of pyriform sinus and epithelial lesions such as simple hyperplasia, different degrees of dysplasia, in situ carcinoma, and invasive carcinoma. In normal epithelium, strong expression of CK-19 was consistently observed only in the basal layer as basic CK, while expression of CK-13 showed a completely reverse pattern, being expressed only in suprabasal layers as stratification-related CK. Characteristic changes in expression pattern of these two CKs were observed in accordance with the degree of epithelial disorders and differentiation of carcinoma. Cytokeratin 1, as keratinization-associated CK, was observed only in keratinized cells of hyperplastic epithelia and well-differentiated carcinomas. These findings may be useful in evaluating epithelial disorders and classifying carcinomas more objectively, and may assist earlier detection of carcinoma when used with standard histologic techniques.

Antibodies, Monoclonal↗
PubMed1990

Inhibitory effect of human plasma and saliva on co-aggregation between Bacteroides gingivalis and Streptococcus mitis.

The effect of human plasma and saliva on co-aggregation between Bacteroides gingivalis and Streptococcus mitis was studied by means of a turbidimetric assay. The co-aggregation activity was obtained from the maximum slope of the absorbance vs. time curve. Its dependence on pH, temperature, and ionic strength was examined, and the number of Bacteroides cells in relation to the number of Streptococcus cells resulting in optimal co-aggregation was established. Co-aggregation inhibition experiments showed that the co-aggregation activity was inhibited by l-arginine and l-lysine, although the activity was unaffected by the sugars tested. Human plasma and saliva were able to inhibit the co-aggregation in a dose-dependent reaction. Plasma exhibited the most potent inhibitory activity in these fluids. Fibrinogen was the most potent inhibitor of the plasma-derived proteins tested. These data suggest the possibility that the oral fluids may modulate the attachment of B. gingivalis to Gram-positive bacteria in periodontal pockets.

Adult↗
PubMed1990

Urinary human growth hormone measurement using a highly sensitive sandwich enzyme immunoassay: diagnostic and therapeutic uses in patients with growth hormone deficiency.

Several reports indicate that urinary hGH excretion is significantly lower in patients with either partial (PGHD) or complete GH deficiency (CGHD) than in normal but short children (NSC) or normal children (NC). However, there is an overlap between the NSC and NC groups and the PGHD group. Using a highly sensitive sandwich enzyme immunoassay, we investigated whether the measurement of urinary hGH can clearly separate the PGHD and CGHD groups from the NSC and NC groups. In addition, we measured the urinary excretion of synthetic methionyl-hGH (met-hGH) in PGHD and CGHD after sc injections of 2 and 4 IU and im injections of 4 IU in an attempt to determine the optimal replacement dose. Total 24-h urinary hGH excretion in each patient examined for 2 consecutive days varied from 1 day to the next. There were no differences in urinary hGH excretions between the NSC group and the NC group. The lower values for daily urinary hGH excretion in the NSC group overlapped some of the higher values in the PGHD group. However, when the mean urinary hGH level of both days was used, the 24-h urinary hGH excretion clearly separated the PGHD (5.5 +/- 2.3 ng/day; range, 1.3-9.2; n = 21) and CGHD (1.9 +/- 0.9 ng/day; range, 0.6-3.6; n = 14) groups from the NSC (12.8 +/- 3.1 ng/day; range, 9.3-17.5; n = 10) and NC (14.6 +/- 3.1 ng/day; range, 10.6-19.0; n = 6) groups without any overlap. A mean urinary hGH value less than 9.0 ng/day during a 2-day collection strongly suggested GH deficiency. Ten of 16 patients with PGHD and CGHD who received 2 IU met-hGH, sc, had urinary hGH levels within the range of the mean +/- SD in NSC. These patients received daily sc 0.097 +/- 0.024 IU/kg hGH injections. These results suggest that the measurement of 24-h urinary hGH excretion is noninvasive, accurate, and useful for the screening of GH deficiency. The mean value on 2 days of 24-h urinary hGH excretion for the screening of GH deficiency is estimated to be less than 9.0 ng/day. The optimal dose of GH as therapy for GH deficiency is demonstrated as daily sc injection of 0.1 IU/kg hGH, 0.7 IU/kg/week. To convert international units of met-hGH to milligrams, divide by 2.4.

Child↗
PubMed1990

Regulation of external work of concentric hypertrophied left ventricles in unanesthetized hypertensive dogs.

This study aimed to evaluate the change in external work and its control mechanism in the concentric hypertrophied heart induced by systemic hypertension. The calculated stroke work, myocardial contractility, afterload, and preload were examined in the baseline period (Control Stage, CS) and in the eighth week after the induction of perinephritic hypertension (Hypertensive Stage, HS) in unanesthetized dogs. These variables were examined with echocardiograms and high-fidelity left ventricular (LV) and ascending aortic pressures. Mean aortic pressure was significantly (p less than 0.05) elevated from 95 +/- 10 to 134 +/- 27 mmHg in HS. The ratio of end-diastolic wall thickness to radius significantly (p less than 0.05) increased in the HS. The calculated stroke work of the LV chamber was significantly (p less than 0.05) increased from 7022 +/- 1203 to 8860 +/- 1548 X 10(3) erg in HS while the stroke work normalized for wall thickness by calculating the wall stress was not altered (3069 +/- 1086 v.s. 2989 +/- 866 erg; CS v.s. HS) with no significant change in heart rate in HS. In the HS, the end-systolic wall stress (afterload) and the slope of end-systolic wall stress-dimension relationship (myocardial contractility) were unchanged while the end-diastolic wall stress (preload) slightly reduced. These results suggest that, in the concentric hypertrophied left ventricle induced by systemic hypertension, the LV myocardial external work is normal, whereas the LV chamber external work increases.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Effects of osmolality on water, electrolytes and VFAs absorption from the isolated ruminoreticulum in the cow.

Effect of the osmolality on the absorption of water, electrolyte and VFAs from the isolated ruminoreticulum under normal feeding condition were investigated in a series of the study to evaluate the rumen as a potential site of absorption in oral fluid therapy of adult cattle. Thirty of 40 l of the test solutions with varying osmotic pressure (100, 200, 300 and 500 mosmol/L, pH 6.8) were prepared using different concentrations of electrolytes and VFAs. These were infused into the isolated and emptied ruminoreticulum, and the absorption rate of water and each components were studied for 3 hrs. Marked absorption of water was observed with solutions more hypotonic than rumen fluid, the extent of which was more extensive with less osmotic pressure; the absorption rate as high as 47.6% was obtained with a solution 100 mosmol in osmotic pressure. When hypertonic solution (500 mosmol/L) was infused, however, water was transported on the contrary from the blood to the rumen. Absorption rates of electrolytes such as Na, K and Cl were increased according to the elevation of osmolalities and their concentrations in the test solutions. VFAs were also absorbed in large quantities (23.9-74.5%) in any test solutions, though the absorption rates were significantly decreased with the elevation of osmolalities. These results may indicate that the ruminal wall has a high absorptive function for water, electrolytes and VFAs when the osmolalities and the concentration of solutes in the ruminal fluid are maintained within a certain range. Furthermore, it is thought that they may work as a rational support for a possible oral fluid therapy even in adult cows.

Acetates↗
PubMed1990

[Prognostic significance of the DNA ploidy of the early glottic cancer].

The stage classification is most frequently used at the present in predicting the outcome of laryngeal carcinoma. Recently, DNA ploidy pattern as detected by DNA flow cytometry and cytofluorometry has been also shown to be predictive. In this study, DNA cytofluorometry was performed on formalin-fixed paraffin-embedded tissues from 18 patients with T1 and T2 glottic squamous cell carcinoma for whom long-term follow-up data were available. The DNA ploidy pattern was classified into three types, diploid, diploid + tetraploid and aneuploid according to the DNA content of Go/G1 cells and mitotic cells. In these 18 cases, 8 cases (44%) had diploid pattern, 3 cases (17%) had the diploid + tetraploid pattern and 7 cases (39%) had the aneuploid pattern. The ploidy pattern was significantly associated with the relapse-free rate, but did not correlate with the stage of the carcinoma and differentiation of the cancer cells. Distribution of the patients by histology, stage and therapy was almost equal among the diploid, diploid + tetraploid and aneuploid groups. All the patients were treated with irradiation (60Gy). In the group as a whole, no patient died of glottic carcinoma. Relapse-free survival rates for diploid, diploid + tetraploid and aneupoid were 88%, 33% and 29% respectively. This retrospective study of glottic cancer treated with radiation therapy suggests the possibility that the DNA ploidy pattern would significantly predict patient outcome and would be useful for selecting patients whose poor prognosis demands more aggressive therapy.

Aged↗
PubMed1990

[A study of the relationship between hearing-aid usage and residual hearing].

Fifty-eight children (from 4 to 19 years of age) with bilateral, symmetrical, sensorineural hearing loss, who had used a hearing aid in only one ear for 1 to 19 years were investigated to study the influence of hearing-aid upon the residual hearing between the used and no used ears. The results were as follows, 1) The average hearing level for the used ear at seven frequencies was 49. 5 dB of pre-hearing-aid usage and was 53. 8 dB of post-hearing-aid usage. The discrepancy of audiograms between the aided and unaided ear was not remarkable. 2) The hearings for both the aided and the unaided ears in Audiograms was progressive for a long time. But no significance relation was observed between changes in used-ear hearing of the aided and unaided ears. 3) When the hearing levels of the children were scrutinised on an individual basis, it was found that 9 cases (15.5%) in both ears, 2 cases (3.4%) in only used ear and 1 case (1.7%) in only no used ear out of 58 cases showed deterioration of hearing. 4) These data did not lead us to the conclusion that hearing-aid usage was detrimental on the residual hearing of children with sensorineural hearing loss.

Adolescent↗
PubMed1990

[Correlation of proliferation index with submucosal invasion of hypopharyngeal cancer].

Proliferation index of biopsied specimens from 11 cases of hypopharyngeal carcinoma was studied immunohistochemically using anti-BrDU monoclonal antibody. S-phase cell labelling index (SLI) was measured and compared with the extent of submucosal invasion that was evaluated histologically in each extirpated specimen by means of continuous large section technique. Conclusions were as follows: 1. The largest SLI was obtained in a moderately differentiated carcinoma, and calculated up to 56, while the smallest was encountered in a well differentiated carcinoma as 18. Mean value in these 11 cases was 35. 2. It seemed likely that moderately or poorly differentiated carcinomas show larger SLI, but its statistical significance could not be delineated in these materials. 3. Submucosal invasion was much longer in the oral direction than in the anal. The longest invasion was observed in a case that showed the largest SLI, and measured up to 22 mm. The shortest invasion, on the contrary, was seen in a case with the smallest SLI, and was only 9 mm. Mean value in these 11 cases was 14.4 mm. 4. SLI correlates well in every case to the extent of submucosal invasion toward the oropharynx. 5. SLI evaluated preoperatively in biopsied specimen may help to indicate an ample safety margin at the surgery.

Carcinoma, Squamous Cell↗
PubMed1990

Assay for the soluble interleukin-2 receptor by sandwich enzyme linked immunosorbent assay.

A system for the detection of soluble IL-2R by sandwich enzyme linked immunosorbent assay (ELISA) was established. This assay system has good reproducibility, and was found to be specific for soluble IL-2R by examination of the binding of anti-IgM antibody or anti-IL-2R monoclonal antibody (mAb) with IgM or soluble IL-2R and inhibition by IL-2 of the binding of anti-IL-2R mAb to soluble IL-2R. The IL-2R molecules in supernatant of phytohemagglutinin-stimulated peripheral blood mononuclear cells were of 44,000-61,000 molecular weight as estimated by size of exclusion high performance liquid chromatography. The results of determinations for soluble IL-2R with a Eurogenetics kit (sandwich enzyme linked immunosorbent assay) were significantly correlated with those by the our method.

Enzyme-Linked Immunosorbent Assay↗
PubMed1990

[Clinical evaluation of high dose rate intra-cavitary irradiation in the treatment of uterine cervical cancer, combined with pepleomycin suppository in uterine cavity].

By means of re-irradiation using pepleomycin suppository in uterine cavity, we attained local control for one patient who had local recurrence in uterine cavity and suffered from uterine fluor in which viable cancer cells were confirmed. We were enlightened by this therapeutic experience, so we attempted combination therapy using pepleomycin suppositories to supplement intra-cavitary irradiation, for the 11 selected patients who were suffering from uterine fluor. We investigated the treatment results in 7 patients of stage III out of 11 patients (of all stages), in comparison with 13 patients of stage III who were treated by irradiation alone. Consequently, these treatment results were approximately equivalent, and the incidence of sigmoid complications could be decreased. Side effects which were followed by the combination therapy were not serious, and so we believe that pepleomycin suppository is a simple method and valuable to supplement radiation therapy of uterine cervical cancer.

Administration, Intravaginal↗
PubMed1990

[Sex differences in schizophrenic delusions].

The authors compared delusions of male schizophrenics (56 cases) with those of female schizophrenics (41 cases) on the following points: 1) characteristics of objects of delusions, i) existence of the central object, ii) their description on this central object, iii) sex of this central object, 2) existence of the erotic-heterosexual delusion, 3) existence of the descent delusion, 4) existence of the sexual cenestopathy, and found that both sexes have many more male objects in their delusions than female objects, and that more women than men have delusions about acquaintances, erotic-heterosexual delusions, and sexual cenestopathy, while more men than women have delusions about distant or abstract objects. Comparing these findings with those of the other authors, the authors discuss them from clinical, psychopathological and psychodynamic perspectives.

Delusions↗
PubMed1990

Beta-lactamase in gram-negative rods: the relationship between penicillinase and R plasmids in gram-negative rods.

Concomitant with the extensive use of antibiotics, the number of multiple antibiotic-resistant strains has been increasing. Since resistance is mainly mediated by R plasmids, we undertook to investigate the characteristics of R plasmid-determined beta-lactamase in 6 Gram-negative rods. The beta-lactamase produced by each organism was classified by its substrate: type P which attacks penicillins, type C which attacks cephalosporins, and type C/P which attacks both penicillins and cephalosporins. Though the chromosomally mediated beta-lactamase of almost all Gram-negative rods is classified as type C, R plasmid-mediated beta-lactamase is almost equally active against both penicillins and cephalosporins. Therefore, we suggest that type C/P beta-lactamase was mediated by R plasmids in Gram-negative rods which already produced chromosomally mediated type C beta-lactamase. The strains which produced type C/P beta-lactamase tended to be more resistant to antibiotics than the other beta-lactamase producing strains. Among type C/P strains, the sensitivity to cephalosporins varied with the bacterial species, whereas all these strains were highly resistant to penicillins. Even for piperacillin, which is stable to cephalosporinase, the MIC at which the cumulative percentage of strains inhibited was 50% (MIC50) was over 50 micrograms/ml in all strains tested.

Cefazolin↗