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Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 1,099 records · Page 61Linked to original sources
PubMed1993

Development of mast cells and basophils: processes and regulation mechanisms.

Mast cells and basophils are offspring of the multipotential hematopoietic stem cell. Although mast cells sometimes are misunderstood as basophils that have invaded connective or mucosal tissue, these two kinds of basophilic cells are distinguishable by morphology and surface antigenicity. Developmental processes of mast cells and basophils are different. Basophils complete their differentiation within the bone marrow, but precursors of mast cells leave the bone marrow, invade connective or mucosal tissue, proliferate, and differentiate into mast cells. The mechanisms regulating development are different between mast cells and basophils. Both T cell-dependent and fibroblast-dependent mechanisms are involved in the development of rodent mast cells, but only the fibroblast-dependent mechanism is known for development of human mast cells and only the T cell-dependent mechanism for the development of basophils of both rodents and humans. The most important cytokine for the T cell-dependent mechanism appears to be interleukin-3, whereas for the fibroblast-dependent mechanism it appears to be the ligand for the c-kit receptor (ie, stem cell factor).

Animals↗
PubMed1993

Epidermal cell viability in rat skin preserved at 4 degrees C.

To determine the longest storage period for the clinical application of epidermal cells and a better method of preservation at 4 degrees C, we stored skin in various fluids and assessed the changes in epidermal cell viability. The time course of changes in the viability of epidermal cells from skin in various preservation fluids was similar to the results obtained with whole skin in previous studies. The best preservation fluid was found to be RPMI 1640 medium, and the best method of preservation was immersion in RPMI 1640 at 4 degrees C with a medium change every 3 days.

Animals↗
PubMed1993

High resolution Tc-99m HMPAO SPECT in a patient with transient global amnesia.

This is a report of a patient who underwent high-resolution brain perfusion SPECT studies during and after an episode of transient global amnesia. During the attack, SPECT imaging showed increased perfusion in the left medial temporal region involving the amygdala and hippocampus. After recovery from amnesia, a follow-up SPECT examination showed slightly decreased perfusion in this region. These findings support the hypothesis that transient global amnesia is associated with transient hyperperfusion in the medial temporal brain structures, and confirm the utility of high-resolution SPECT imaging for the evaluation of the fine details of functional brain anatomy.

Adult↗
PubMed1993

Renal perfusion with Tc-99m DTPA--simple noninvasive determination of extraction fraction and plasma flow.

A simple, noninvasive method for the determination of extraction fraction and renal plasma flow in Tc-99m DTPA studies is presented. This method could be performed in conjunction with the measurement of glomerular filtration rate, providing additional information about renal plasma flow. Graphic analysis of the Patlak plot was employed for the determination of the unidirectional influx rate constant (ku) of Tc-99m DTPA from the blood to the kidney and the initial nonspecific distribution volume (Vn) in the kidney. The first pass extraction fraction was estimated from Ku and Vn, assuming a bolus input to the kidney. The glomerular filtration rate was measured by renal counting corrected for depth and dose. Using the estimated extraction fraction (EF) and glomerular filtration rate (GFR), the renal plasma flow (RPF) was calculated using the formula of RPF = GFR/EF. In a total of 76 kidneys in 38 patients (including 9 patients with normal renal function and without evidence of nephrourologic disease), the value of renal plasma flow showed good correlation with that of effective renal plasma flow measured by renal counting with I-131 orthoiodohippuran. There was a characteristic tendency for the extraction fraction to show a larger value as the renal plasma flow decreased. These results indicate that this method is valid for renal plasma flow estimation and the determinations of extraction fraction and renal plasma flow in Tc-99m DTPA studies is helpful as an adjunct to the measurement of glomerular filtration rate in order to adequately assess the pathophysiologic changes of renal disorders.

Adult↗
PubMed1993

Comparative SPECT study of stroke using Tc-99m ECD, I-123 IMP, and Tc-99m HMPAO.

Brain perfusion SPECT imaging using Tc-99m ethyl cysteinate dimer (ECD) was carried out in 12 patients with chronic cerebrovascular disease. The sensitivity of lesion detection and lesion-to-normal tissue contrast was compared with those of I-123 IMP and Tc-99m HMPAO. Eight patients underwent all three studies and the remaining four patients had Tc-99m ECD and I-123 IMP scans. The sensitivity of lesion detection and lesion contrast was analyzed quantitatively using an asymmetric index determined by the equation: 100 x [right - left[/(right + left). In the cerebral cortex, cerebellum, and white matter, I-123 IMP showed higher lesion sensitivity than Tc-99m ECD and Tc-99m HMPAO. In the striatum and thalamus, Tc-99m ECD and I-123 IMP showed higher lesion sensitivity than Tc-99m HMPAO. I-123 IMP showed the highest lesion contrast in cerebral cortex and cerebellum, whereas Tc-99m ECD showed the highest contrast in thalamus and striatum. In all regions, Tc-99m ECD showed higher lesion contrast than Tc-99m HMPAO. These results suggest regional variation in the sensitivity of lesion detection and lesion contrast of Tc-99m ECD compared to I-123 IMP, and the superiority of Tc-99m ECD to Tc-99m HMPAO.

Adult↗
PubMed1993

Prolonging discordant xenograft survival with anticomplement reagents K76COOH and FUT175.

The guinea pig heart, when transplanted into the rat heterotopically, is rejected within 30 min via activation of the alternative complement pathway. Natural antibody does not contribute to rejection. This xenotransplantation model was used to assess the effect of anti-complement reagents on discordant xenograft survival. In vivo administration of K76COOH (K76) to rats induced only slight suppression of factors B and D and a marked decrease of C3, leading to the depression of ACH50 (reflecting the potency of the alternative pathway). On the other hand, FUT175 (FUT) reduced C3 activity by about 80% and inhibited factor B activity nearly 100% < 1 hr after the administration, but inhibited factor D activity only marginally. FUT abrogated ACH50 for > 6 hr. Of note, the xenograft beating time was prolonged approximately 3 times by FUT but not by K76, suggesting that direct inhibition of plasma serine protease factor B results in the complete suppression of ACH50 and graft survival. The administration of both K76 and FUT resulted in the longest graft survival, but the effects of these reagents were abolished by additional antigraft antibody. Anticomplement reagents that block factor B and C3 are therefore effective for prolongation of discordant xenograft survival when the graft rejection is associated with the complement alternative pathway.

Animals↗
PubMed1993

Protective immunity and mast cell and eosinophil responses in mice infested with larval Haemaphysalis longicornis ticks.

WBB6F1-+/+ mice were infested with larval Haemaphysalis longicornis ticks twice at an interval of 14 days: apparent resistance against ticks was expressed in the second infestation. The first infestation induced degranulation of a small number of mast cells at the feeding sites within 6 days, and resulted in two-fold increases of mast cell numbers on day 14 with a significant elevation of total immunoglobulin E (IgE) levels in sera and high proportion of IgE-bound mast cells. The second infestation resulted in the intensive degranulation of the increased mast cells at the feeding sites. Eosinophils infiltrated into the feeding sites of ticks: the second infestation led to a greater maximal level of the infiltrating eosinophils. These data suggest that the resistance against larval H. longicornis ticks in mice may be expressed as a result of immediate hypersensitivity and many eosinophils infiltrating from the blood to the feeding sites might contribute to the tick rejection.

Animals↗
PubMed1993

Test for ability of decay-accelerating factor (DAF, CD55) and CD59 to alleviate complement-mediated damage of xeno-erythrocytes.

We investigated the susceptibility to human complement (C) of xeno-erythrocytes into which phosphatidylinositol (PI)-anchored human C regulatory protein, decay-accelerating factor (DAF) or CD59 had been incorporated. Erythrocytes of sheep (Esh), swine (Esw), dog (Edg), and guinea pig (Egp), unsensitized with human natural antibody (Ab), were used as xeno-target. C-mediated lysis of erythrocytes (E) was induced in both classical and alternative pathways in parallel with the density of the sensitized Ab, except for Egp. The efficacy of DAF/CD59-mediated protection of the xeno E from human C, however, differed among these E species. In both classical and alternative pathways, Esh or Esw, which are non-activator surfaces, were protected by the incorporated DAF or CD59, DAF being more effective than CD59. On the other hand, CD59 was more effective than DAF in both pathways in protection of Egp, which is an alternative pathway activator. To elucidate this different behaviour of DAF and CD59, C3 step inhibition by the incorporated DAF or CD59 was measured. DAF was effective in the suppression of classical pathway-mediated C3 deposition in Esh, Esw and Egp, but not in Edg, while CD59 exhibited negligible effects in this regard. Next, inhibition of the lysis by CD59 was tested by haemolytic assay. CD59 did not block the C5b-8-mediated lysis in any xeno E. It also barely blocked C5b-9-mediated lysis, except in the case of Egp, in which CD59 partly blocked C9 attack. Membrane constituents on targets other than the incorporated complement inhibitors may be a crucial factor in the induction of cytolysis and, presumably, in hyperacute rejection.

Animals↗
PubMed1993

Effects of internal and external Na+ ions on inwardly rectifying K+ channels in guinea-pig ventricular cells.

1. The effects of internal and external Na+ ions on the inwardly rectifying K+ channel were studied in guinea-pig ventricular cells. 2. Single-channel currents through the inwardly rectifying K+ channel were recorded in the open cell-attached or inside-out configuration at 150 mM internal K+ and either 150 or 25 mM external K+. Internal Na+, at a concentration of 5-40 mM, reduced the unitary amplitude of the outward current. No increase in open-channel current noise was detected with the filter cut-off frequency of 3 kHz. Substate behaviour seen with internal Mg2+ at a micromolar level was not observed. The inward currents were little affected by internal Na+. 3. The unitary current-voltage relation rectified inwardly in the presence of internal Na+ in a concentration-dependent manner. 4. Outward unitary currents were normalized to those measured in the absence of Na+. The normalized current-voltage relation was shifted in the negative direction by 20-25 mV by decreasing external K+ from 150 to 25 mM, indicating that the blocking effect increases with low external K+ when compared at a fixed voltage. 5. The normalized current-Na+ concentration curve was fitted by a one-to-one binding curve at each voltage. In a semi-logarithmic plot of dissociation constant versus membrane potential, data points for 150 and 25 mM external K+ were fitted by straight lines with nearly the same slope. The dissociation constant at 0 mV is 154 mM in 150 mM external K+ and 89 mM in 25 mM external K+. The voltage dependence of dissociation constants gives a value for the effective valency of the Na+ ion of around 0.5. 6. To study effects of external Na+, single-channel currents were recorded with pipette solutions containing 125 mM Na+, 125 mM choline or 125 mM N-methyl-D-glucamine (NMDG) in addition to 25 mM K+. Current amplitude was smaller with choline than with Na+ or NMDG. The reduction in current amplitude with choline was more evident in the inward current, resulting in a stronger outward rectification of the current-voltage relation. This finding and prolonged mean open time (see Summary point 7) was interpreted by assuming that choline is an open-channel blocker. 7. The lifetimes of the openings in the inward currents were distributed according to a single exponential. The mean open time with Na+ was similar to that with NMDG, which decreased with hyperpolarization. The mean open time with choline was much longer and less voltage dependent.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Voltage-dependent block by internal Ca2+ ions of inwardly rectifying K+ channels in guinea-pig ventricular cells.

1. The block of the inwardly rectifying K+ channel by intracellular Ca2+ was studied in guinea-pig ventricular cells. 2. Single-channel currents through the inwardly rectifying K+ channel were recorded in the inside-out configuration at 150 mM external and internal K+. Internal Ca2+, at a concentration of 0.4-10 microM, induced subconductance levels with one-third and two-thirds of the unitary amplitude in the outward currents without affecting the inward currents. 3. Occupancy at each sublevel was estimated from the amplitude histogram which showed four equally spaced peaks in the presence of internal Ca2+. At different degrees of blockade, the distribution of the current levels showed a reasonable agreement with the binomial theorem. 4. The outward mean open-channel currents were measured at different Ca2+ concentrations and voltages. The current-voltage relation rectified inwardly in the presence of internal Ca2+ in a concentration-dependent manner. 5. The outward mean open-channel currents were normalized to unitary amplitudes in the absence of Ca2+. The normalized current-Ca2+ concentration curve was fitted by saturation kinetics with a Hill coefficient of 1 at each voltage. The voltage dependence of the dissociation constants gives the value for the fractional electrical distance of the Ca2+ binding site of 0.7. 6. The dwell times in each substrate were distributed exponentially. On the assumption that the inwardly rectifying K+ channel of cardiac cells is composed of three identical conducting subunits and each subunit is blocked by Ca2+ independently, the blocking (mu) and unblocking (lambda) rates were calculated. The value of mu increased with higher Ca2+ concentrations or larger depolarizations, while lambda was independent of Ca2+ and decreased with larger depolarization. 7. It is thus concluded that internal Ca2+ produces a voltage-dependent block of the channel to cause inward rectification although the blocking effect is less potent than that of Mg2+. The substate behaviour seen with internal Ca2+ supports the triple-barrelled structure of the cardiac inwardly rectifying K+ channel.

Animals↗
PubMed1993

[Treatment of experimental invasive pulmonary aspergillosis in rats with liposomal amphotericin B].

Liposomal amphotericin B was evaluated for toxicity, pharmacokinetic properties and therapeutic efficacy in invasive pulmonary aspergillosis in Sprague-Dawley rats. The protective effect of liposomes against the toxicity induced by repeated amphotericin B infusions was observed in a survival study of rats, thereby allowing higher dosages to be administered. Pharmacokinetic studies showed that liposomes led to high levels of amphotericin B in the spleen and liver. Drug levels in the lung were higher at ten minutes after intravenous injection of liposomal amphotericin B at 20 mg/kg than of free amphotericin B at 1.5 mg/kg. Efficacy was assessed in rats treated with cortisone acetate, fed a low-protein diet and infected transtracheally with 8 x 10(4) Aspergillus fumigatus spores to cause fetal pneumonia and pulmonary bleeding. Dosages of 20 or 4 mg/kg of liposomal amphotericin B, or 1.5 mg/kg of free amphotericin B were administered intravenously to rats once daily for 8 days. Control rats received saline. Twenty mg/kg of liposomal amphotericin B was as effective on survival rate as 1.5 mg/kg of free amphotericin B. However, 4 mg/kg of liposomal amphotericin B was less effective than 1.5 mg/kg of free amphotericin B, prolonging the mean survival time of rats treated with saline, which showed elevation of galactomannan antigen titers of Aspergillus fumigatus in sera and invasive proliferation or mycelia with bleeding in histopathological sections of the lung. We conclude that liposomal amphotericin B reduces toxicity of the drug, thereby increasing the concentration of the drug in the lung by high-dose administration, but decreases the efficacy of the drug in experimental pulmonary aspergillosis.

Amphotericin B↗
PubMed1993

Cutaneous leishmaniasis in mast cell-deficient W/Wv mice.

Genetically mast cell-deficient W/Wv mice infected with Leishmania amazonensis showed progressive development of ulcerative skin lesions. However, no significant differences between the W/Wv mice and the normal littermates with respect to size of the lesions, anti-Leishmania immunoglobulin E antibody, and the number of eosinophils accumulated in the lesions were observed.

Animals↗
PubMed1993

Pulsed Doppler echocardiographic assessment of portal venous flow patterns in patients after the Fontan operation.

OBJECTIVE: To assess the effect of the condition of the right heart after the Fontan operation on portal venous flow, and to determine whether the characteristics of portal venous flow were different when there was an atriopulmonary connection with atrial septal closure rather than an atriopulmonary or total cavopulmonary connection with intra-atrial routing. PATIENTS AND METHODS: After the Fontan operation six patients with an atriopulmonary connection (group 1), three patients with an atriosubpulmonary connection (group 2), four patients with intra-atrial routing and an atriopulmonary connection (group 3), and five patients with a total cavopulmonary connection (group 4) were studied by pulsed Doppler echocardiography. The flow signals were recorded for the pulmonary artery, hepatic vein, and intrahepatic portal vein in each patient. Postoperative cardiac catheterisation was performed in 16 of the 18 patients. The Doppler findings were compared with those of 14 controls. RESULTS: The portal flow was pulsatile in 13 patients and constant in five patients. Reversed flow was shown at or just after the QRS wave after hepatic venous regurgitation in two group 1 patients. The flow signal was interrupted in two group 1 patients and two group 2 patients. Decrease in velocity of flow was recorded in two group 1 patients, one group 2 patients, three group 3 patients, and one group 4 patient. Portal flow was constant in one group 3 patient and four group 4 patients. The pulsatility ratio ranged from -0.46 to 0.49 (mean (SD), 0.03 (0.32)) in the patients from group 1 and 2, from 0.41 to 0.76 (0.54 (0.15)) in group 3, and from 0.70 to 0.80 (0.75 (0.04)) in group 4. The ratio in the controls ranged from 0.29 to 0.83 (0.61 (0.13)). The ratio was significantly lower in groups 1 and 2 than in group 3 (p < 0.01), group 4 (p < 0.01), or the controls (p < 0.005). There was no significant difference in the ratio between group 3 and group 4 and no correlation between the pulsatility ratio and the cardiac index (r = 0.26), mean right atrial pressure (r = 0.25), or pulmonary vascular resistance (r = 0.17). CONCLUSION: The larger hepatic venous regurgitation caused by atrial contraction in patients with an atriopulmonary connection correlated with the higher portal pulsatility and a total cavopulmonary connection reduced portal pulsatility.

Atrial Function, Right↗
PubMed1993

Diffuse cerebral hypoperfusion in epileptic patients observed from quantitative assessment with single photon emission computed tomography using N-isopropyl-(iodine-123)-p-iodoamphetamine.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 15 epileptic adult patients receiving chronic high-dose antiepileptic drug therapy and 22 normal volunteers matched for sex and age, using single photon emission computed tomography with N-isopropyl-(iodine-123)-p-iodoamphetamine. The entire averaged rCBF value in the epileptic patients, i.e. 52.8 +/- 13.7 ml/10 g/min (range: 25-78 ml/100 g/min), was significantly lower as compared with that in the normal subjects, i.e. 69.1 +/- 14.2 ml/100 g/min (range: 46-102 ml/100 g/min). Six of the 15 patients showed absolute rCBF values less than the minimum of the normal range, i.e. 46 ml/100 g/min, in all or most of the measured brain tissues. There was a significant correlation between the diffuse cerebral hypoperfusion and simultaneous ingestion of phenytoin and phenobarbital. The possible effects of antiepileptic drugs on rCBF are discussed.

Adult↗
PubMed1993

Probable cerebellar abnormality on N-isopropyl-(iodine-123)-p-iodoamphetamine single photon emission computed tomography scans in an epileptic patient receiving long-term high-dose phenytoin therapy.

Quantitative assessment of regional cerebral blood flow (rCBF) was performed in a 22-year-old man with intractable temporal lobe epilepsy on long-term high-dose phenytoin (PHT) therapy, using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine. In all the SPECT scans repeated three times with changes in the PHT dose, absolute rCBF values were lower in most of the cerebral and cerebellar regions measured, as compared with 5 normal subjects matched for sex and age, and 22 normal subjects including the 5 men. Both the cerebellar to frontal rCBF ratio and cerebellar to cerebral rCBF ratio in the patient persistently showed low values, probably reflecting abnormal relative cerebellar hypoperfusion, whereas X-ray computed tomography and magnetic resonance brain imaging showed no abnormal findings. However, this probable cerebellar abnormality on SPECT was to some degree reversible with decreases in the PHT dose. These results suggest the utility of SPECT scans for early detection of cerebellar abnormalities known to be often present in epileptic patients, and imply a risk of long-term high-dose PHT therapy.

Adult↗
PubMed1993

A case of pheochromocytoma of the urinary bladder in a long-term hemodialysis patient.

The development is reported of a pheochromocytoma of the urinary bladder in a 33-year-old patient with systemic lupus erythematosus who had undergone long-term hemodialysis. A hypertensive episode followed by defecation was demonstrated by the monitoring of blood pressure with a portable automated sphygmomanometer without elevation of plasma catecholamines. The tumor was surgically removed and normalization of the patient's blood pressure followed. Thus, monitoring of blood pressure for 24 h proved useful for the diagnosis of pheochromocytoma and, in particular, of paroxysmal hypertension.

Adult↗