[Efficient diagnosis using results of simple tests].
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Biomarkers↗
Biomedical subjects
N Matsuda
Publications and source records attributed to N Matsuda.
Studies on selectin blockers. 2. Novel selectin blocker as potential therapeutics for inflammatory disorders.
As a part of our studies of selectin blockers, we prepared 1-(2-tetradecylhexadecyl)-3'-O-sulfo Le(X) 1 and 1-(2-tetradecylhexadecyl) sLe(X) 2 and examined their inhibitory activities against natural ligand (sLe(X)) binding to E-, P-, and L-selectins. Compounds 1 and 2 were 2 times more potent than the sLe(X) tetrasaccharide toward E-selectin binding and up to 4 times more potent than sLe(X) toward P- and L-selectin binding. Interestingly, compound 1 provided dose-dependent protective effects against an immunoglobulin E-mediated skin reaction in mouse ears. This protective effect was associated with diminished tissue accumulation of neutrophils in the ear (as assessed by myeloperoxidase). These findings indicate that the modification of sLe(X) or 3'-O-sulfo Le(X) with a "branched anchor", a 2-tetradecylhexadecyl group, is useful in the design of a more potent selectin blocker, which has broad inhibitory activities toward all selectins.
Animals↗
Genetic polymorphisms of the cancer related gene and Helicobacter pylori infection in Japanese gastric cancer patients. An age and gender matched case-control study.
BACKGROUND: Gastric cancer is a multistage process, each caused by numerous factors. The objective of this study was to elucidate the risk factors for gastric cancer by using molecular epidemiologic techniques and serum markers. METHODS: Serum pepsinogen I levels, pepsinogen I/pepsinogen II (I/II) ratios, serum IgG antibody against Helicobacter pylori (H. pylori), and genetic polymorphisms of cytochrome p450 2E1 (CYP2E1), glutathione-S-transferase M1 (GSTM1), and L-myc protooncogenes were analyzed in 82 persons with gastric cancer and in 151 age- and sex-matched controls, who were selected from 208 gastric cancer patients and 375 noncancer patients, respectively. Statistical analysis was performed to elucidate which risk factors for gastric cancer were contributing the most to gastric carcinogenicity. RESULTS: Serum pepsinogen I level (odds ratio [OR] = 1.81; 95% confidence interval [CI], 1.04-3.16) and pepsinogen I/II ratios (OR = 3.09; 95% CI, 1.74-5.49) were significantly associated with gastric cancer risk in a case-control study. Seropositivity of serum IgG antibody against H. pylori (OR = 1.25; 95% CI, 0.84-1.85) and specific genotypes of a L-myc genetic polymorphism (OR = 1.33; 95% CI, 0.59-2.99) were more commonly observed in gastric cancer cases, but this was not statistically significant. Specific genotypes of the CYP2E1 RsaI polymorphism and GSTM1 gene deletion were not associated with gastric cancer. CONCLUSIONS: Atrophic mucosal change, indicated by serum pepsinogen levels, is possible a risk factor for gastric cancer. H. pylori infection and genetic polymorphisms of CYP2E1, L-myc, and GSTM1 genetic polymorphisms were not risk factors in this study.
Adult↗
Sodium--potassium pump current in rabbit sino-atrial node cells.
1. The Na(+)-K+ pump current (Ip) was studied in sino-atrial (SA) node cells of rabbits using the whole-cell patch-clamp technique. 2. With 50 mM Na+ in the pipette solution ([Na+]pip), changing the external K+ concentration (-K+-o) from 0 to 5.4 mM caused the holding current to shift in an outward direction and reach a new steady state. The current-voltage relationships obtained by subtraction of current traces recorded at 0 mM Ko+ from those recorded at 5.4 mM Ko+ revealed time-independent and voltage-dependent characteristics. The external K(+)-induced current was completely blocked by external application of 10 microM ouabain, indicating the existence of Ip in SA node cells of rabbit heart. 3. Ip increased as [K+]o increased. With 30 mM Na+pip, Ip at 0 mV was activated by [K+]o with non-linear least-squares fit parameters for the Hill equation of K0.5 of 1.4 mM and a Hill coefficient (nH) of 1.2 (n = 7). 4. The cation dependence of the K+ site of the Na(+)-K+ pump was examined using various monovalent cations. The sequence was K+ > or = Rb+ > Cs+ > > > Li+. 5. Ip at 0 mV also increased as [Na+]pip was increased from 10 to 150 mM at 5.4 mM Ko+, with a K0.5 value of 14 mM and a nH of 1.3 (n = 54). 6. Ip at 0 mV was reduced by lowering the temperature from 37 to 25 degrees C with 30 mM Na+pip and 5.4 mM Ko+. The temperature coefficient (Q10) for Ip was 2.1 (n = 27). 7. With 10 mM Na+pip and 5.4 mM Ko+, the half-activation voltage of Ip was -52 +/- 16 mV and the current at this voltage was 22.5 +/- 3.5 pA (n = 10), indicating that Ip contributes significantly to the background outward current during the normal pacemaker potential of SA node cells.
Animals↗
Interferon alfa induces leukocyte capillary trapping in rat retinal microcirculation.
BACKGROUND: Interferon alfa has been suggested as a possible treatment for choroidal neovascularization. However, retinal complications following interferon therapy have been reported. OBJECTIVE: To evaluate the effects of interferon alfa on leukocyte dynamics in the rat retinal microcirculation. METHODS: Interferon alfa of different doses was intravenously administered in rats. Leukocyte dynamics were observed with acridine orange digital fluorography, which uses a nuclear fluorescent dye of acridine orange and scanning laser ophthalmoscopy. This technique allows visualization of leukocyte movements in the retinal microcirculation in vivo. RESULTS: After interferon alfa was administered, leukocytes adhered to vascular walls and became trapped in the retinal microcirculation. Leukocyte trapping was dose-dependent. CONCLUSIONS: Interferon alfa increased leukocyte adherence to vascular endothelium and subsequent leukocyte trapping in the retinal capillaries. Interferon alfa may activate leukocytes, and activated leukocytes may be involved in the pathogenesis of microinfarction associated with interferon-induced retinopathy.
Acridine Orange↗
Different metastatic potentials of ras- and src-transformed BALB/c 3T3 A31 variant cells.
The metastatic phenotype of tumor cells is thought to be induced by an aberrant signaling cascade or cascades that are different from those required for tumorigenicity. Oncogene-transfected cells with different tumorigenicities and metastatic potentials have been used to identify such pathways and responsible molecules. However, oncogenes that can induce tumorigenicity in recipient cells also frequently induce the metastatic phenotype at the same time. The difficulty in obtaining cell lines that are tumorigenic but not metastatic has hampered such studies. In this report, we transfected the activated c-Ha-ras oncogene into BALB/c 3T3 A31 variant cells and found that the transfectants were tumorigenic but they did not form metastatic lung modules in the experimental metastasis assay. The phenotype was very stable and was maintained during cultivation. On the other hand, the metastatic potentials of either the transfected cells or the original variant cells could be induced by transfection of the v-src oncogene. The src transfectants formed extensive nodules in lung when injected into the tail veins of congeneric mice. The cell motility of the metastatic src transfectants on Matrigel-coated dishes was greater than that of the ras transfectants. The src transfectants were also invasive in Matrigel when analyzed on a filter. These variant cells transformed by the ras and src oncogenes will be a useful system for identifying the signaling cascades responsible for the metastatic potential of tumors.
3T3 Cells↗
Effects of calcium in continuous cardioplegia on myocardial protection.
The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca (0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37 degrees C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1 +/- 2.9%, 80.6 +/- 2.0%, and 71.5 +/- 3.7% (mean +/- SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.
Animals↗
An Arabidopsis gene isolated by a novel method for detecting genetic interaction in yeast encodes the GDP dissociation inhibitor of Ara4 GTPase.
The Arabidopsis Ara proteins belong to the Rab/Ypt family of small GTPases, which are implicated in intracellular vesicular traffic. To understand their specific roles in the cell, it is imperative to identify molecules that regulate the GTPase cycle. Such molecules have been found and characterized in animals and yeasts but not in plants. Using a yeast system, we developed a novel method of functional screening to detect interactions between foreign genes and identified this Rab regulator in plants. We found that the expression of the ARA4 gene in yeast ypt mutants causes exaggeration of the mutant phenotype. By introducing an Arabidopsis cDNA library into the ypt1 mutant, we isolated a clone whose coexpression overcame the deleterious effect of ARA4. This gene encodes an Arabidopsis homolog of the Rab GDP dissociation inhibitor (GDI) and was named AtGDI1. The expression of AtGDI1 complemented the yeast sec19-1 (gdi1) mutation. AtGDI1 is expressed almost ubiquitously in Arabidopsis tissues. The method described here indicates the physiological interaction of two plant molecules, Ara4 and GDI, in yeast and should be applicable to other foreign genes.
Amino Acid Sequence↗
Enhancement of the L-type Ca2+ current by mechanical stimulation in single rabbit cardiac myocytes.
Anion conductance is known to be activated by mechanical stimulation, such as osmotic cell swelling or cell inflation via the patch pipette, of canine or rabbit cardiac myocytes. The effects of mechanical stimulation on time-dependent currents, however, remain unsettled. Using the whole-cell voltage-clamp method, we have found that mechanical stimuli enhance the L-type Ca2+ current (ICa,L) in rabbit cardiac myocytes. At every membrane potential, ICa,L was reversibly increased by osmotic cell swelling and by cell inflation caused by applying a positive pressure of 10 to 15 cm H2O via the patch pipette. ICa,L was increased during cell inflation by 37 +/- 21% (mean +/- SD, n = 17) in atrial cells and by 37 +/ -8% (n = 7) in sinoatrial node cells in solution containing 2 mmol/L Ca2+. The current-voltage relationship, the inactivation time constant, the steady state inactivation curve, and the conductance properties of ICa,L were all virtually unaffected by mechanical stimulation except for the open probability, which appears to increase. The increase in ICa,L was not dependent on protein kinase A, since an inhibitor peptide of cAMP-dependent protein kinase failed to prevent the increase in ICa,L during mechanical stimuli (n=5). The increase in ICa,L caused by cell inflation was unaffected by the chelation of intracellular Ca2+ by the addition of 10 mmol/L EGTA or 10 mmol/L BAPTA to the pipette solution, suggesting that the effect was not mediated by changes in intracellular Ca2+. Thus, mechanical stimulation due to cell swelling or inflation may itself directly increase ICa,L in rabbit cardiac myocytes.
Animals↗
Major risk factors for atherosclerosis are manifested in experimental Ca-deficiency.
The eggshell is the major source of Ca required during growth of chick embryos. Therefore, chick embryos placed ex ovo for long-term (SL) are rendered severe systemic calcium deficiency. We report here that SL chick embryos express Ca-deficiency related atherogenic disorders, and that in vitro Ca-deficiency induces dedifferentiation, i.e. loss of cell-type specific features and accelerated proliferative activities, in the various types of cultured cells. Systemic blood pressure is significantly higher and an accelerated weight gain of the heart is noted in SL compared to normal embryos (NL) at the incubation Day-14. Plasma cholesterol was lower, while triglyceride and glucose were higher in SL. Varying Ca in the culture medium (FCa, 1.8 mM; HCa, 2.8 mM; Ca/2, 0.9 mM) clearly affected the phenotype of the cultured cardiomyocytes and vascular cells isolated from the chick embryos. The cell number and total DNA were significantly larger and the level of LDH and proliferating cell nuclear antigen (PCNA) was elevated in Ca/2 compared to FCa. On the contrary, the level of CPK and contractile proteins were lowered in Ca/2. Thus, it is indicated that Ca-deficiency induces atherogenic disorders in vivo, and accelerates cell proliferation and decelerates sarcomeric protein expression in vitro. Taken together, it is suggested that the atherogenic, developmental disorders in SL may be the integrated result of the phenotype alteration in the various cell types directly induced by Ca-deficiency.
Animals↗
Porphyromonas gingivalis reduces mitogenic and chemotactic responses of human periodontal ligament cells to platelet-derived growth factor in vitro.
The effects of a sonicated Porphyromonas gingivalis ATCC 33277 protein extract on the mitogenic and chemotactic responses of human periodontal ligament (PDL) cells to the recombinant human platelet-derived growth factor-BB homodimer (PDGF-BB) were examined in vitro. Proliferation of PDL cells was inhibited by P. gingivalis extract at concentrations higher than 10 micrograms/mL protein. At 100 micrograms/mL of P. gingivalis extract, cells did not proliferate. DNA synthesis in PDL cells, as revealed by [3H]-thymidine incorporation, was also inhibited by approximately 50% in the presence of 50 micrograms/mL P. gingivalis extract for 24 hours. In contrast, PDGF-BB at 1 ng/mL enhanced DNA synthesis in PDL cells, followed by maximum enhancement at concentrations higher than 10 ng/mL PDGF-BB. However, this mitogenic response to PDGF-BB was markedly reduced in the presence of 20 micrograms/mL of P. gingivalis extract and did not reach the maximum level even if PDGF-BB concentrations were increased to 250 ng/mL. PDL cells exhibited a chemotactic response to PDGF-BB at 1 ng/mL, which was also inhibited by pretreatment of the cells with P. gingivalis extract at 10 to 50 micrograms/mL. Scatchard analysis of a [125I]-PDGF binding assay demonstrated that PDL cells have both high and low PDGF binding affinity sites. Treatment of the cells with P. gingivalis extract decreased the number of PDGF-binding sites to approximately 35% of the control level, while it caused only a slight change in the affinities of both types of binding site. These results indicated that the P. gingivalis extract reduced mitogenic and chemotactic responses of human PDL cells, possibly through mechanisms involving a decrease in PDGF-binding capacity of these cells. Due to this inhibitory effect of P. gingivalis, the normal levels of PDGF in periodontal lesions may not be sufficient to promote periodontal regeneration through activation of PDL cell proliferation and migration. Therefore, the therapeutic use of PDGF-BB, as a supplement to pre-existing PDGF and as an adjunct, while also eliminating P. gingivalis from periodontal lesions, would help periodontal tissue regeneration.
Bacterial Proteins↗
Evaluation of retinal microcirculatory alterations in the Goto-Kakizaki rat. A spontaneous model of non-insulin-dependent diabetes.
PURPOSE: To evaluate retinal microcirculation in the spontaneous diabetic GK (Goto-Kakizaki) rat over an extended time. METHODS: The dye-dilution technique with scanning laser ophthalmoscope-based fluorescein angiography was used to evaluate retinal circulation in GK rats with diabetes of 1, 3, and 5 months' duration and in age-matched controls. Scanning laser ophthalmoscope fluorescein angiograms were recorded after a 10-microliter bolus of 10% sodium fluorescein was injected into the tail vein, followed by a flush of 0.1 ml saline. Retinal mean circulation times (MCTs), vessel diameters, and retinal segmental blood flows (SBFs) were determined using computer-assisted image analysis on a frame-by-frame basis. RESULTS: The MCTs were significantly prolonged (P< 0.01) in the GK rat groups (2.60 +/- 0.31, 2.74 +/- 0.28, and 2.84 +/- 0.38 seconds at 1, 3, and 5 months' duration of diabetes, respectively) compared to the age-matched controls (1.94 +/- 0.20, 1.99 +/- 0.12, and 1.91 +/- 0.22 seconds, respectively). No significant differences were observed in the retinal arterial and venous diameters between groups at each time period. The SBFs were significantly reduced (P< 0.03) in the GK rat groups (12.0 +/- 1.5, 12.1 +/- 2.0, and 11.8 +/- 2.5 x 10(2) micrometer squared/second at 1, 3, and 5 months' duration of diabetes, respectively) compared to the controls (16.0 +/- 2.2, 16.7 +/- 1.8, and 17.2 +/- 2.5 x 10(2) micrometer squared/second, respectively). In either group, no significant changes with growth were observed in MCT, vessel diameters, or SBF, although the MCTs in the GK rat group tended to lengthen, and arterial and venous diameters in the GK rat group tended to increase with duration of diabetes. Goto-Kakizaki rats did not exhibit dense cataracts, the retinal circulation could be observed, and morphologic changes of diabetic retinopathy did not develop throughout the experimental period. CONCLUSIONS: A significant prolongation in MCT and a significant reduction in SBF appeared in GK rats at an early stage in diabetes. This tendency continued until 5 months' duration of diabetes. These results suggest that retinal circulatory abnormalities are found before observable retinopathy development in GK rats and that there may be some mechanism causing a reduction in SBF without changing major retinal vessel diameters at an early stage in non-insulin-dependent diabetes mellitus (NIDDM). In addition, this study demonstrates that the GK rat will be a useful model of non-insulin-dependent diabetes mellitus to evaluate retinal circulation over an extended time.
Animals↗
Visualization and quantitative analysis of leukocyte dynamics in retinal microcirculation of rats.
PURPOSE: Recent studies have demonstrated that leukocytes play an important role in microcirculatory flow disturbances. A few methods are available to investigate leukocyte dynamics in retinal microcirculation. The authors explored leukocyte dynamics in the retina of rats with acridine orange digital fluorography. METHODS: Acridine orange digital fluorography produces high-resolution images from a scanning laser ophthalmoscope with the use of a fluorescent nuclear dye of acridine orange, which has been used for staining nucleic acids of cells in histochemical and cytochemical studies. The images were recorded on S-VHS tapes and were investigated with a personal computer-based image analysis system. RESULTS: Fluorescent leukocytes in the retinal microcirculation were visualized. Highly magnified images could be obtained because of the high dioptric power of the rat eye compared with the primate eye. It was possible to observe leukocyte deformation in narrow capillaries and nuclei of vascular endothelium. At arteriolar bifurcations, leukocytes moved preferentially into the branch with the higher flow rate. "Preferential channels" were identified in which predominantly leukocytes were delivered; the channels were characterized by high flow velocity and a straight, short capillary route. The average leukocyte velocities of the arteries, veins, and capillaries are 29.5 +/- 7.3, 17.4 +/- 5.3, and 1.4 +/- 0.4 mm/second, respectively. CONCLUSIONS: This study demonstrates that microcirculatory dynamics of leukocytes can be visualized and analyzed quantitatively in rats in vivo with acridine orange fluorography. This method may be a promising tool to reveal how leukocytes contribute to retinal flow disturbances under various pathologic conditions.
Acridine Orange↗
Visualization of leukocyte dynamics in the choroid with indocyanine green.
PURPOSE: To report a method to evaluate leukocyte dynamics in the choroidal circulation with indocyanine green (ICG) angiography. METHODS: Nonpigmented and pigmented rats were administered ICG solution intravenously. The fundus image was obtained with a scanning laser ophthalmoscope and recorded on magnetic tapes at a video rate (30 frames/second). The images were analyzed with a personal computer-based image analysis system. RESULTS: On ICG angiography, hyperfluorescent dots were seen moving along the choroidal vessels and in the retinal vessels several minutes after injection. These fluorescent dots were thought to be circulating leukocytes stained with ICG. The micrographs of blood smears after ICG injection showed intense fluorescence of leukocytes. Computer-assisted image analysis allowed tracing of these fluorescent dots using a frame-by frame method. CONCLUSIONS: Results of this study indicated that ICG can be used for vital staining of leukocytes and that it is possible to evaluate leukocyte movement in the choroidal circulation in vivo in rats.
Animals↗
[Derivation of latent reference intervals from routine laboratory database: its principle, validity and methodological implications for laboratory informatics].
A new method to derive reference from routine laboratory database intervals was developed. It depends on (1) availability of multiple screening tests results, (2) initial estimates for the reference intervals (RI) and (3) exclusion of data with multiple abnormalities in "related" test items. We designated those data which remained after exclusion as "latent reference values". RI was calculated from them parametrically employing a modified Box-Cox power transformation and maximal likelihood method. After RI were derived for all the items, they were used as a new set of RI estimates and the series of exclusion/calculation procedures were repeated for 7 times. The validity of the latent reference intervals (LRI) derived from routine biochemical screening test results were evaluated in three ways, by comparing them (1) with RIs determined conventionally from healthy individuals, and (2) with LRIs derived from qusi-normal individuals (blood donors), and (3) with LRIs obtained from a simulated healthy population which was generated as multivariate normal random values.
Adult↗
[Reentrant tachycardia].
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Electrocardiography↗
[Blood chemical analysis. C. Key points in sampling for ionized Ca determination].
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Blood Specimen Collection↗
A 256-channel magnetometer for brain research.
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Adult↗