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Biomedical subjects

K Noda

Publications and source records attributed to K Noda.

At least 361 records · Page 20Linked to original sources
PubMed1990

Detection of human papillomavirus (HPV) type 16 and 52b in cervical cancer tissues by Southern blot hybridization and polymerase chain reaction (PCR).

DNA samples from cancer tissues diagnosed histologically as squamous cell carcinoma of the uterine cervix were examined for the presence of human papillomavirus (HPV) genome DNA by Southern blot hybridization. Of 63 specimens, 32 were found to hybridize with HPV DNA probes; 23 specimens (35%) with HPV type 16 (HPV16), one (2%) with HPV type 18 (HPV18), four (7%) with HPV type 52b (HPV52b), and four others (7%) weakly with HPV52b. Specimens negative for HPV DNA with Southern blot hybridization were subjected to polymerase chain reaction (PCR) to determine the presence of HPV DNA under more sensitive conditions. After PCR using one set of primers specific for HPV16 and HPV52b, 7 out of 31 specimens were found to have HPV16 DNA. None was positive for HPV52b DNA. Our results indicate that HPV52b, as well as HPV16 and HPV18, is associated with squamous cell carcinoma of uterine cervix, and more sensitive determination of HPV infection can be made by amplification of the viral genome by PCR.

Base Sequence↗
PubMed1990

Erythrocytes from diabetics with neuropathy have fewer sodium pumps.

Erythrocytes from diabetics with neuropathy had fewer binding sites for ouabain and, therefore, fewer sodium pumps than did erythrocytes from diabetics without neuropathy or from age-matched controls (P less than 0.001). Diabetics with neuropathy excreted in their urine significantly less C-peptide immunoreactivity (CPR) than those without neuropathy, which is a sign of lower endogenous insulin secretion levels. Significant positive correlations existed between the number of pumps and tibial motor nerve conduction velocity (MNCV) and urinary CPR in diabetics, and between urinary CPR and MNCV. This suggests that there is close correlation between the fall in the number of pumps in diabetics and diabetic neuropathy and insulin deficiency.

Biomarkers↗
PubMed1990

No correlation between tumor markers and prognosis under polygenic control systems.

Tumor markers in serum should not be correlated with the prognosis of patients with malignant tumors, although the markers indicate the presence of tumors, since marker levels and prognosis are controlled independently by poly-genes. Furthermore, prognostic factors, including incidence of pulmonary metastasis, tumor growth rate, tumor drug sensitivity and host response, vary among patients. In general, tumor markers may be used to demonstrate response of tumor to treatments only when expression of the markers does not change in a time-dependent manner.

Biomarkers, Tumor↗
PubMed1990

Autonomy in tumor cell proliferation.

Autonomous replication of tumor cells seems to be an essential factor in the definition of the malignant tumor itself, although tumor cell proliferation is, in general, controlled by the host response including immunological reactions and microenvironment. The cause of the autonomy can hypothetically be classified into four categories as follow: (a) auto- and paracrine growth stimulation; (b) growth factor receptor abnormalities; (c) abnormal signal transduction; (d) self-incitement of 'initiator-replicon' system in DNA replication. These intracellular mechanisms may play important roles in the autonomy as shown in autocrine growth factors from the data obtained in protein-free cell culture. Hypothetically, negative regulation systems on the initiator-replicon may play roles of cell replication in multicellular organisms. Oncogene products and growth factors may affect this regulation system.

Animals↗
PubMed1990

Mitogenic activity of soluble preparations from Plasmodium berghei-infected erythrocytes to L3T4+, Lyt2- and L3T4-, Lyt2+ T-cell subsets.

The mitogenic activity of soluble preparations of Plasmodium berghei-infected erythrocytes (PBEP) in cultures of T or non-T cells isolated from spleens of naive mice was investigated. The proportion of cells at each phase in the cell cycle was examined by flow cytometry after incubation with various concentrations of PBEP; the proliferation index (PI-cell numbers at S, G2 and M phases/cell numbers at all phases x 100) was calculated. An addition of PBEP led to significant increases in the PI levels of T cells, but not in those of non-T cells. Moreover, when PBEP were added to L3T4+, Lyt2- (helper) or L3T4-, Lyt2+ (suppressor) T-cell fractions separated from rosette-forming T cells in spleens, significant increases in PI levels were detectable in both helper and suppressor T-cell cultures. These results indicate that PBEP have a mitogenic activity directed to both helper and suppressor T-cell fractions isolated from spleens of naive mice and that PBEP or Plasmodium parasites may in this way induce complicated immune responses during malaria infection.

Animals↗
PubMed1990

Purification and characterization of an acidic amino acid-specific endopeptidase of Bacillus subtilis obtained from a commercial preparation (Protease Type XVI, Sigma).

An acidic amino acid-specific endopeptidase was purified from Protease Type XVI (Sigma), a commercial product from culture filtrate of Bacillus subtilis, by a series of column chromatographies on CM-Toyopearl (Fractogel) and Mono-S, guided by activity assay using Boc-Ala-Ala-Pro-Glu-pNA as a substrate. The final preparation was homogeneous on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and reversed-phase HPLC. The molecular weight of the protease was estimated to be 18,000 by gel filtration on TSK gel G3000SWXL column using 6 M guanidine hydrochloride as an eluent, and 17,000 by SDS-PAGE in the presence of 2-mercaptoethanol. The isoelectric point of the protease was 7.7. Studies on the substrate specificity with peptide p-nitroanilides and natural peptides revealed that the protease hydrolyzes the peptide bonds on the carboxyl-terminal side of acidic amino acids, especially of glutamic acid. The protease was completely inactivated by DFP, indicating the serine protease nature of the protease. The activity of the protease was also inhibited by EDTA and GEDTA, and reactivated by Ca2+. The protease contained 1.3 +/- 0.2 mol/mol protein of Ca2+. These results suggest that Ca2+ plays a vital role in the protease activity.

Amino Acid Sequence↗
PubMed1990

A facile method for preparation of t-butyloxycarbonylamino acid p-nitroanilides.

A series of p-nitroanilides of t-butyloxycarbonylamino acids, including Boc-Trp, Boc-Asn, Boc-Gln, Boc-Ser(But), Boc-Thr(But), Boc-Asp(OBut), Boc-Lys(TFA), and Boc-His(Boc), were prepared conveniently by the mixed anhydride method using 2,2-dimethylpropanoic chloride (pivaloyl chloride). The products were obtained in 40-60% yields after purification by column chromatography on Sephadex LH-20. p-Nitroanilide of histidine was purified after deprotection of Boc-His(Boc)-pNA and obtained as H-His-pNA.2HCl.

Amino Acids↗
PubMed1990

Influence of tabletting speed on compactibility and compressibility of two direct compressible powders under high speed compression.

To examine the influence of tabletting speed on compactibility and compressibility under high speed compression, two direct compressible powders, alpha-lactose monohydrate and microcrystalline cellulose of different particle size ranges were compressed using an instrumented rotary press with varying tabletting speed and compression force. The maximum applied force and total time during compression (contact time) were determined from a time-force profile, and the relation between these parameters and properties of compacts was examined. For all lactose tablets, the porosity and tensile strength of compacts were less affected by compression rate though they depended on the applied force. However, the properties of microcrystalline cellulose tablets were varied depending on the tabletting speed in addition to the applied force. In an attempt to quantitatively evaluate the effect of compression rate on the compactibility, an empirical equation was derived from the numerical analysis of the experimental data. The compactibility parameters deduced from the equation well elucidated the effect of tabletting speed on the properties of microcrystalline cellulose tablets and lactose tablets made of various particle size powders.

Chemistry, Pharmaceutical↗
PubMed1990

Efficacy of emetic and United State pharmacopoeia ipecac syrup in prevention of drug absorption.

The efficacy of both the emetic syrup prepared in the previous report and the United States Pharmacopoeia (USP) ipecac syrup concerning the prevention of drug absorption was investigated in 4 beagle dogs using a randomized and cross-over design. In order to control the intragastric pH of the beagle dogs, the administration of pentagastrin or hydrochloric acid (HCl)-glycine buffer (pH 1.5) was tested. The intragastric pH changed from 7.2 to 1.8 with the intramuscular administration of pentagastrin, but the primary emesis occurred more slowly. On the other hand, the HCl-glycine buffer (pH 1.5) gave the appropriate emesis. Therefore, the HCl-glycine buffer (pH 1.5) was used to control the intragastric pH of the beagle dogs. Acetaminophen (AcA), salicylic acid (SA) and kanamycin (KM) as markers were administered orally after conditioning the intragastric pH at 1.5. The emetic syrup or the USP ipecac syrup was then administered. The recovery rate of AcA and KM from vomit was 42-65%. The emetic syrup and the USP ipecac syrup significantly reduced the absorption of AcA from the calculation of pharmacokinetic parameters compared to the control syrup. It was observed that the absorption of cephaeline (CP) in the emetic syrup was less than that of CP in the USP ipecac syrup.

Absorption↗
PubMed1990

Influence of internal structure on kinetics of drug release from wax matrix tablets.

To examine the influence of the internal structure of a wax matrix tablet on in vitro drug release, the release rates of several tablets consisting of various proportions of drug and wax were compared with the water penetration rates from the compressed and lateral surfaces of the tablets. The penetration rates from the lateral surface were found to be much faster than those from the compressed surface in all cases. A theoretical equation involving a two-dissolving-direction was derived on the basis of the boundary retreating concept. The retreating rate constants deduced from the dissolution results were well coincident with the values directly determined by the needle penetration method, suggesting good applicability of the proposed equation. The results suggest that the tortuosity of the water channels created in a tablet during dissolution is generally smaller in the horizontal direction than that in the vertical direction. This would be caused by the drug particles or granules being elongated in the horizontal direction by compression.

Chemistry, Pharmaceutical↗
PubMed1990

An analysis of experimental radiation carcinogenesis with model setting for competing risks.

The mean life span of animals killed by a specific type of tumor and the incidence of that particular tumor are influenced by competing risks. A parametric approach for censored samples was applied to correct for the competing risks. The life span distribution under each risk wherein the other risks were thought to be eliminated is assumed to be a Weibull distribution. Our data were from an experiment on tumor induction by X-rays in mice: whole body irradiation with 600 R; head with 800 R; trunk with 800 R; or lower body with 800 R. Analysis of the results shows that the mean appearance time of malignant lymphomas was accelerated by whole body irradiation. Acceleration of lung tumors was relatively large after trunk irradiation. Mammary tumors were accelerated by whole body, trunk or lower body irradiation.

Animals↗
PubMed1990

Participation of ovarian 20 alpha-hydroxysteroid dehydrogenase in luteotrophic and luteolytic processes during rat pseudopregnancy.

In normal rats, before Day 12 of pseudopregnancy, minimal levels of 20 alpha-HSD activity were detected in functional CL whereas those in the residue were 3-5 times higher. When ovulation was blocked for more than 2 weeks by placing rats in a continuously lit environment before the induction of pseudopregnancy, only minimal levels of 20 alpha-HSD activity were detectable in the functional CL and residue before Day 12. In normal pseudopregnant rats, there was a linear increase in 20 alpha-HSD activity from Day 12 to 15 in the functional CL and residue, but the rate of elevation was much higher in functional CL. This tendency was much more clear-cut in rats in the continuous lighting. In immature rats in which pseudopregnancy was induced by PMSG and hCG treatment, 20 alpha-HSD activity peaked twice. The first small peak was attributed to the early regression of some of the large number of corpora lutea, and the changes in 20 alpha-HSD activity in most of the corpora lutea paralleled those in rats in continuous lighting. Bromocriptine abolished the prolactin surges, and in normal pseudopregnant rats an increase in 20 alpha-HSD activity in functional CL started from 12 h and the rate of the increase was accelerated from 36 h afterwards, while a relatively small increase was observed in the residue at 18 h and later.(ABSTRACT TRUNCATED AT 250 WORDS)

20-alpha-Dihydroprogesterone↗
PubMed1990

Decreased VIP content in peripheral nerve from streptozocin-induced diabetic rats.

After induction of diabetes with streptozocin (STZ-D) in rats, we measured vasoactive intestinal polypeptide (VIP) content in sciatic nerve and spinal cord obtained from nondiabetic, untreated STZ-D, and insulin-treated STZ-D rats. Eight weeks after the onset of diabetes, caudal nerve conduction velocity (NCV) in the untreated STZ-D rats (n = 13) was slower than in the controls (n = 11; mean +/- SE 30.9 +/- 0.6 vs. 41.4 +/- 1.8 m/s, P less than 0.001). The decrease in NCV was less marked in the insulin-treated STZ-D rats (n = 11; 36.3 +/- 0.9 m/s, P less than 0.05 vs. control). VIP content in sciatic nerve decreased in the untreated STZ-D rats (1.33 +/- 0.23 ng/g wet wt) compared with the other groups (control, 3.10 +/- 0.44, P less than 0.01; insulin-treated STZ-D, 2.44 +/- 0.55, P less than 0.05). However, in spinal cord, VIP content was not significantly different among the three groups. The VIP levels in sciatic nerve showed a positive correlation with NCV (r = 0.430, P less than 0.01). In addition, an inverse correlation between VIP levels and blood glucose levels was observed (r = -0.5624, P less than 0.001). NCV was also inversely correlated with blood glucose levels (r = -0.7662, P less than 0.001). Together with a previous morphological study, these findings suggest a possible causal relationship between reduced VIP content and diabetic neuropathy.

Animals↗
PubMed1990

Quantification of physical and cyto-physiological conditions for the electrofusion of Saccharomyces cerevisiae.

Various conditions for obtaining hybrids of the auxotrophic mutants SH1509 and SH1512 of Saccharomyces cerevisiae by electrofusion were investigated. An AC field of 400 Vp/cm and a DC field of 2 square pulses (7 kV/cm; 60 microsec each) at an interval of 0.5 sec were effective. Treatment with 0.2 (SH1509) or 1.0 mg/ml (SH1512) Zymolyase for 1 or 1.5 hr was essential. As to the molarity of the osmotic stabilizer (sorbitol), the hybrid yield peaked at 0.6 M. The presence of CaCl2 (up to 0.4 mM) or 0.1 mM CaCl2 with 0.1 mM MgCl2 enhanced the yield. The temperature of the spheroplast suspension during pulsations also affected the yield, the most suitable temperature being 28 degrees C.

Buffers↗
PubMed1990

[Condition to produce oscillation after twitch shortening in the bullfrog geniohyoid muscle].

Two different types of elastic behaviors could be distinguished in the twitch contraction curve of the isolated frog geniohyoid muscle under changing of chemical conditions; one was negative oscillation that occurred after completion of the relaxation phase which was sequential to a typical cyclic pattern demonstrated in the contraction and relaxation period, and the other was oscillation which occurred in the phase of plateau formation during relaxation. The former will relate to the parallel elastic component (the effect of caffeine combined with a low Ca++ condition) and the latter will to the series one (collagenase and dantrolene). The causal or genetic relationship is not yet clarified.

Animals↗
PubMed1990

[One possible mode of protective actions of mucin in the digestive canal].

This report describes an additional fact indicating the protective action of mucopolysaccharide in the digestive canal. Roughly speaking, the living organism is composed of structural and functional (physiologically active) substances. Through experimental observations, we have now got the theoretical idea that a functional substance not only possesses a proper inherent activity but has acquired new accessory activities during developmental course. For example, as shown in the previous papers, the authors have revealed that mucin, which is originally an intensive lubricant to make or to transfer the bolus, can be an agent to initiate, maintain or promote the spontaneous movement of the isolated intestinal strip. In this paper, when acetylcholine is applied to the bathing solution of the strip together with eserine, its promotive effect on the spontaneous movement is abolished by mucin probably because of direct binding which renders acetylcholine ineffective.

Acetylcholine↗