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Biomedical subjects

M Miyake

Publications and source records attributed to M Miyake.

At least 289 records · Page 16Linked to original sources

Effects of divalent cations and saccharides on Vibrio metschnikovii cytolysin-induced hemolysis of rabbit erythrocytes.

Divalent cations and polysaccharides such as inulin and dextran reversibly inhibited hemolysis of rabbit erythrocytes caused by Vibrio metschnikovii cytolysin. On the basis of the 50% inhibitory doses, the cations were divided into two groups, group I (Cd2+, Cu2+, Ni2+, Sn2+, and Zn2+) and group II (Ba2+, Ca2+, Co2+, Mg2+, Mn2+, and Sr2+). Neither divalent cations nor polysaccharides interfered with the binding of toxins to the erythrocyte membrane. Group I cations disturbed tetramer formation of cytolysin on the cytolysin-lysed erythrocyte membrane, although group II cations and dextran did not affect the process. Erythrocytes treated with cytolysin in the presence of group II cations or dextran lysed after transfer to toxin- and inhibitor (group II cations or dextran)-free buffer at both 37 and 4 degrees C. However, erythrocytes treated in the presence of group I cations lysed at 37 degrees C but not at 4 degrees C, indicating that group I cations block the temperature-dependent lesion (tetramer)-forming step subsequent to the binding of cytolysin to the erythrocytes. The cytolysin-treated erythrocytes swelled in a colloid osmotic manner, and the swelling was preceded by the binding and the lesion-forming steps. It is also suggested that the lysis of the erythrocytes proceeds in a temperature-independent manner and that the cytolysin does not bind to the erythrocytes at 4 degrees C. These findings suggest that the sequence of V. metschnikovii cytolysin-induced hemolysis is defined by three steps: (i) a temperature-dependent binding step, (ii) a temperature-dependent lesion-forming step, and (iii) a temperature-independent lysis step.

Animals↗

Differences in intracellular calcium mobilization by interferon-beta and interferon-gamma in RPMI-4788 cells.

Human interferon (IFN) stimulates a 1.5- to 1.7-fold transient increase in the concentration of cytoplasmic-free calcium ion ([Ca2+]i) within 10-20 s upon exposure of RPMI-4788 cells to IFN. This early event of IFN-induced [Ca2+]i mobilization was measurable by loading the cells with Fura-2AM, a fluorescent Ca2+ indicator. The mobilization induced by IFN-beta or IFN-gamma was dependent on the concentration of each IFN. The increased [Ca2+]i gradually returned to its resting level within 60 s. The addition of EGTA (0.5-10 mM) to medium induced a marked decrease in the amount of [Ca2+]i mobilized by IFN-beta and a partial decrease by IFN-gamma. This finding suggests that the mechanisms of [Ca2+]i mobilization by IFN-beta and IFN-gamma might be different. While IFN-beta-induced mobilization may be mainly from an influx of the extracellular calcium ion ([Ca2+]o), IFN-gamma-induced mobilization may be a summation of an influx of [Ca2+]o and a release from intracellular Ca2+ stores.

Calcium↗

Effect of protein binding on high performance liquid chromatography analysis of drugs with an internal-surface reversed-phase silica column.

The effect of protein binding on the high performance liquid chromatography (HPLC) elution profile of drugs injected directly onto an internal-surface reversed-phase (ISRP) silica column was investigated. When a relatively large volume (greater than or equal to 100 microliters) of the sample solution containing warfarin and bovine serum albumin (BSA) was applied directly onto the ISRP column and elution was carried out with the mobile phase containing an organic modifier, two distinct peaks, both due to warfarin, appeared separated from the protein peak. The peak splitting was not observed in the case of antipyrine-BSA mixed solution, where the protein binding is weak. It was found that the drug bound at the strong-binding site on the BSA molecule was released slowly during the process of chromatography and was eluted as the first peak with a shorter retention time, while the drug bound at the weak-binding site was released quickly, and was eluted as the second peak together with the free drug. The warfarin-BSA interaction at the strong-binding site was evaluated, under minimum influence from the other binding site, from the warfarin concentration obtained from the first peak and the free warfarin concentration determined by the ultrafiltration method.

Animals↗

Determination of free drug in protein binding equilibrium by high-performance frontal analysis using internal-surface reversed-phase silica support.

An internal-surface reversed-phase silica column was employed in the frontal analysis method to determine free drug concentration in warfarin (Wf)-bovine serum albumin (BSA) mixed solution and in indomethacin(Im)-BSA mixed solution. When a 4-ml portion of aqueous solution containing 2-30 microM Im and 28 microM BSA and a 10-ml portion of aqueous solution containing 0.5-175 microM Wf and 28 microM BSA were applied, the elution curves reached a plateau level corresponding to both free drug and drug-BSA complex (beta-plateau), followed by another plateau due to free drug alone (gamma-plateau). The drug concentration at the gamma-plateau agreed well with the free drug concentration determined after ultrafiltration of the same solution. The gamma-plateau was observed even when the applied volume was reduced to a level which was insufficient to produce the beta-plateau. The injection of a 400-microliters portion of the 0.5-100 microM Im and 28 microM BSA mixed solution and a 90-microliters portion of 50 microM Im and 550 microM BSA mixed solution onto the ISRP silica column gave a clear gamma-plateau. Compared to the conventional frontal analysis, the present method can determine a wide range of drug levels with much smaller injection volume. This method is applicable to plasma. By a single frontal analysis, both free and total concentrations of carbamazepine in plasma were determined simultaneously.

Animals↗

[Clinical study of the anti-calculus effect of a dentifrice containing sodium polyphosphate].

A double-blind clinical study was conducted to evaluate the effect of a tartar-control dentifrice containing 1% sodium polyphosphate as tartar control agent compared with dentifrice A containing 5% sodium pyrophosphate and a placebo dentifrice. One hundred forty-eights who continued to have a degree of calculus formation after using a regular dentifrice containing no tartar control agent for 1 month in the pretest, were stratified randomly on the basis of pretest, calculus score, age and sex into 3 homogeneous groups. All subjects who received initial prophylaxis were provided the assigned dentifrice and toothbrush. No instructions regarding frequency or method of toothbrushing were allowed. Assessment of supragingival calculus was made at 4 and 12 weeks using the calculus scoring procedure proposed by Volpe et al. Side effects such as oral irritation, ablation of oral mucosa and discoloration of teeth caused by dentifrices were also diagnosed after 12 weeks of use. The following results were obtained in this study. 1. The test dentifrice had reduced (P less than 0.01) supra-gingival calculus significantly more than dentifrice A and the placebo at 12 weeks. 2. A significant reduction (P less than 0.01) was observed when dentifrice A was compared with the placebo dentifrice. 30.1% reduction was obtained using the test dentifrice and 9.0% reduction using dentifrice A when assessed in subjects who had a pretest VMI score of more than 6.0. 3. No side effects caused by the dentifrice which contained sodium polyphosphate were observed.

Dental Calculus↗

Construction of a maxillary prosthesis with a hollow obturator by the balloon technique and a case report.

The authors devised a new method for making a maxillary prosthesis with a hollow obturator, which was named the Balloon Technique. This new technique has a number of advantages over the conventional method in that it not only facilitates the molding of a soft plastic hollow obturator in a single process, but also simplifies the trial fitting of the completed obturator. Furthermore, it makes possible firm adhesion of the hollow obturator and the denture base by the hot-melt method while the denture base resin is cured. Finally, the completed maxillary prosthesis is extremely light.

Aged↗

[Clinical observation following the use of neotriozinc pasta as root canal filling pasta].

The prognosis was examined of root canal filing using Neotriozinc Pasta. Thirty teeth followed up included 40 infected root canals, aged between 14 and 67 years, and observed from 1 to 30 days. Results were evaluated from both criteria of clinical symptoms and roentgenographic findings. The results were as follows: 1. A good evaluation was recorded for 87.5% of the 40 canals treated. 2. There were differences between single-rooted teeth and multi-rooted teeth in this study. 3. A better results were obtained in molar group than incisor one.

Adolescent↗

[Surgical management of pulmonary metastasis from carcinoma of the uterine cervix].

The present study was designed to evaluate the efficacy of surgical management of pulmonary metastasis from carcinoma of the uterine cervix. We saw 609 cases of carcinoma of the uterine cervix from 1979 to 1987, and during the same period also saw 110 cases of recurrent carcinoma of the uterine cervix. Fourteen of these 110 cases were identified as having pulmonary metastasis, and in 11 of 14 cases the recurrent tumors were limited to the lung. Seven of these 11 cases underwent pulmonary resection. Six of the 7 survived more than 2 years after pulmonary resection. Among them, 1 patient has survived more than 4 years, and 1 patient more than 8 years. The tumor cells were thought to metastasize to the lung through the vertebral venous plexus (Batson's plexus) which was suggested as a metastatic route by Thomford et al. in their report on recurrent colon cancer. As a result of this study, if the recurrent tumor is clinically limited to the lung in patients with recurrent carcinoma of the uterine cervix, they should be treated by surgical resection of the pulmonary tumor.

Adenocarcinoma↗

[Monoclonal antibodies directed to human lung cancer].

Recently many monoclonal antibodies are applied in the clinical diagnosis of human cancers. Most of the antigens recognized by these monoclonal antibodies are carbohydrate in their chemical nature. Among these carbohydrate antigens, the sialyl SSEA-1 antigen is particularly useful for the diagnosis of lung cancers, as the elevated serum level of the sialyl SSEA-1 antigen is frequently observed in patients with adenocarcinoma of the lung (ca. 45-75%). Some of the other carbohydrate antigens, such as CA19-9, are also known to be useful for the diagnosis of lung cancers. These carbohydrate antigens are preferentially found in the sera of patients with adenocarcinoma of the lung, while the SCC antigen (TA-4) is closely associated with squamous cell carcinoma of the lung, and NSE (neuron-specific enolase) is frequently detected in the sera of patients with small cell carcinoma of the lung. The specific serum diagnosis of lung cancer of each histological type is now feasible because of the development of these appropriate tumor markers.

Animals↗

Stage-specific expression of SSEA-1-related antigens in the developing lung of human embryos and its relation to the distribution of these antigens in lung cancers.

The localization of three carbohydrate antigens, Lex, Ley, and sialylated Lex-i, which are closely related to stage-specific embryonic antigen 1, in the lung of developing human embryos was investigated using specific monoclonal antibodies. In the 38-day-old embryo, when the primitive lung bud has appeared and developed into two lung sacs, only Ley antigen was specifically positive in the proliferating cells in the terminal portion of lung bud. In the 50-53-day-old embryos, the future bronchi were actively developing from the bronchial buds. At this stage, the Ley antigen was maximally expressed and the Lex antigen appeared in the bud cells. In the lung of the 12-week-old embryo, buds for the future bronchioles were lined by simple cuboidal epithelial cells, which were strongly positive for Lex antigen, weakly positive for Ley antigen, and still completely negative for sialylated Lex-i antigen. Sialylated Lex-i antigen finally appeared in 18-week-old embryos, in the cells of the terminal buds for the future alveoli. At this stage, the Lex and Ley antigens were already beginning to disappear and were only weakly positive in cells of terminal buds. At 20 weeks, only sialylated Lex-i antigen was weakly detected in the cells in the terminal buds; after 8 months, all three antigens were essentially not detected in the respiratory cells in most of the embryos examined in this study. Formation of bronchial glands was detected at 18 weeks, where the developing gland cells were specifically positive for sialylated Lex-i antigen. Ciliation of the bronchial epithelial cells started at 12 weeks and propagated thereafter. The ciliation was accompanied by the reappearance of Ley and Lex antigen in the epithelial cells. These findings collectively indicated that the three antigens all have a physiological significance as stage-specific developmental antigens of the human lung; those antigens were specifically present in the bud cells at each important step of the morphogenesis of the human lung, such as cells in the lung buds, bronchial buds, and terminal buds for the formation of the alveolus, and cells differentiating into bronchial gland cells. The three antigens gradually disappear in the later stage of development along with the maturation process of the lung. Stage-specific embryonic antigen 1 and related antigens are known to be associated with various human cancers, including lung cancers. We suggest that the expression of these antigens in the lung cancer cells is the result of the retrodifferentiation of the cancer cells to the stages of immature embryonic lung cells.

Adenocarcinoma↗

Generation of two murine monoclonal antibodies that can discriminate N-glycolyl and N-acetyl neuraminic acid residues of GM2 gangliosides.

Since the preliminary analyses of the glycolipids of small cell carcinomas of the lung showed an increase of GM2 ganglioside, we generated new murine monoclonal antibodies directed to GM2 to identify the molecular species of the glycolipid. The monoclonal antibodies MK2-34 and MK1-16 (both IgM), which specifically detect N-glycolyl GM2 and N-acetyl GM2, respectively, were generated by immunizing mice with liposomes containing monophosphoryl lipid A, trehalose dimycolate, and the antigenic ganglioside. Among the glycolipid preparations extracted from the cancer tissues of 39 patients with lung cancer, a significant amount of N-acetyl GM2 was detected with MK1-16 antibody in 70% of the squamous cell carcinoma cases, 50% of the lung adenocarcinoma cases, 33% of the large cell carcinoma cases, and 100% of the cases of small cell carcinoma of the lung. On the other hand, N-glycolyl GM2 which was defined by the monoclonal MK2-34 was not found in any of the glycolipid fractions prepared from the lung cancer tissues examined in this study. Immunohistochemical studies of the lung cancer tissues with the MK1-16 antibody showed that the N-acetyl GM2 was present not only in small cell carcinoma tissues as one of the antigens related to tumors of neuroectodermal origin, but also in the squamous cell carcinoma and adenocarcinoma of the lung with a comparable frequency. The appearance of the N-acetyl GM2 antigen correlated well with the degree of differentiation of the cancer cells in patients with squamous cell carcinoma and adenocarcinoma of the lung.

Animals↗

Interferon-gamma activates the voltage-gated calcium channel in RPMI 4788 cells.

Interferon (IFN) increases cytoplasmic free calcium ([Ca2+]i) in RPMI 4788 cells, a human colon cancer cell line. Addition of IFN to the cells loaded with Fura-2, a fluorescent Ca2+ indicator, causes an immediate increase in [Ca2+]i, which is the earliest event after IFN stimulation. A cyanine dye, dis-C3- (5) was used to determine the effects of IFN on the membrane potential in cancer cells. The depolarization was seen with IFN-gamma, but not with IFN-beta. These results taken together, suggest that the IFN-gamma and -beta induced [Ca2+]i mobilization are clearly different in their dependence on Ca2+ entry through voltage-gated Ca2+ channels.

Calcium↗

Fucosylated type-2 chain polylactosamine antigens in human lung cancer.

Four specific monoclonal antibodies (MAbs) have been used to study distributions of fucosylated type-2 chain polylactosamine antigens, Lex, poly Lex, Ley and sialylated Lex-i antigens, in human lung cancer tissues and in the serum of patients with lung cancers. Radioimmunoassay frequently showed abnormally high antigen levels in the sera of 66 lung cancer patients tested. When histological typing was performed, high serum levels of the above 4 antigens were most frequently observed in patients with adenocarcinoma of the lung; i.e., after combining the results from the 4 antigens, 75% of the sera from patients with lung adenocarcinoma were positive (50% in the case of large-cell carcinoma, 30% in the case of squamous-cell carcinoma and 27% for small-cell carcinoma). Among the 4 antigens, the sialylated Lex-i antigen had the highest positive incidence, 58%, in the sera of patients with adenocarcinoma of the lung, compared to 33% for Ley, 29% for poly Lex, and 8% for Lex antigen. On the other hand, when the distributions of these antigens in the lung cancer tissues of 42 patients were studied by immunohistological techniques, the Ley antigen had the highest positive incidence, 100%, in lung adenocarcinoma tissues, poly Lex antigen had 86%, sialylated Lex-i antigen had 71%, and Lex antigen had 29%. In cancer tissues, the incidence of non-sialylated antigens, such as Ley, poly Lex and Lex antigens, often exceeds the positive incidence of the sialylated antigen, but the sialylated form of the antigen, such as sialylated Lex-i antigen, appears more often than the non-sialylated form in patients' sera.

Adenocarcinoma↗

Lymphocyte subsets in human thymoma studied with monoclonal antibodies.

Lymphocyte subsets were investigated using OKT series monoclonal antibodies and flowcytometry in 16 cases of thymoma. From the viewpoint of lymphocyte subsets, thymoma could be divided into three types: thymus lymphocyte type, peripheral lymphocyte type, and intermediate type. In thymus lymphocyte type, the number of OKT-6+ cells exceed that of OKT-3+ cells, and are more than 50%. In peripheral lymphocyte type, the number of OKT-6+ cells are less than that of OKT-3+ cells and less than 10%. In intermediate type, OKT-6+ cells are between 10% and 30%. These three types correlate well with the histologic features with respect to the number and distribution of lymphocytes in thymoma tissue. Lymphocytes were infiltrating abundantly and intermingled in the tumor cell nests in thymus lymphocyte type, and were infiltrating rather scantly and outside the nests in peripheral lymphocyte type.

Adolescent↗

Lactate dehydrogenase isoenzyme-1 in the mediastinal yolk sac tumor.

LDH isozymes in both the serum and tumor tissues of 4 patients with mediastinal yolk sac tumors, and in the cystic content of tumors transplanted into nude mice was examined. Our findings suggested that LDH-1, along with AFP, is an important marker of this tumor, and that LDH isozyme study is necessary for its diagnosis.

Adolescent↗