Biomedical subjects

T Ueda

Publications and source records attributed to T Ueda.

At least 757 records · Page 42Linked to original sources

PubMed1994

Distribution of surfactant and ventilation in surfactant-treated preterm lambs.

Surfactant-deficient ventilated preterm lambs were treated with 100 mg/kg of surfactant radiolabeled with microspheres at 30 min and 2.5 h of age to evaluate the effect of treatment technique on surfactant distribution. The treatments were four positions with four boluses (bolus 4), two lateral positions with two boluses (bolus 2), or a 30-min infusion (infusion). The bolus groups had uniform surfactant distributions to the > 100 pieces analyzed for each lung. Infusion resulted in a very nonuniform surfactant distribution (P < 0.01). Surfactant was recovered equivalently in all lobes of the bolus groups, whereas infusion lungs contained surfactant preferentially in upper lobes (P < 0.01). The second dose of surfactant localized into the same lung doses as the first dose (P < 0.001). Blood flow increased proportionately to surfactant content in the bolus groups. With infusion, blood flow decreased and ventilation measured with 99Tc-labeled aerosol increased to pieces of lung receiving large amounts of the infusion surfactant, suggesting that localized overinflation was likely. Physiological measurements indicated better responses to bolus treatments, although the infusion lambs did improve. These results indicate that different treatment techniques can have large effects on surfactant distributions.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1994

Developmental changes of sheep surfactant: in vivo function and in vitro subtype conversion.

Developmental differences in the intrinsic characteristics of surfactant have not been evaluated. Therefore, heavy-subtype surfactant was recovered from alveolar washes of 132-, 139-, and 148-day preterm lambs, 2- to 3-day-old newborn ventilated lambs, and adult sheep. The density of heavy-subtype surfactant and surfactant protein-A-to-saturated phosphatidylcholine ratios increased significantly with developmental age. In contrast, percent conversion from heavy to light surfactant forms was more rapid for surfactant from preterm animals than for surfactant from mature or adult animals. The function of the heavy-subtype surfactant was tested by treating ventilated 27-day gestational age preterm rabbits. The surfactant from the most immature animals was less effective at improving compliance or maintaining lung volumes on deflation than was surfactant from newborn or adult animals. These results demonstrate intrinsic and functional differences in surfactant from developing compared with mature sheep that correlated with the surfactant protein-A-content. The pattern of changes indicates that the preterm animal is at a disadvantage, because the surfactant is intrinsically abnormal relative to that of the adult.

Aging↗

PubMed1994

Evaluation of risk of hemorrhagic transformation in local intra-arterial thrombolysis in acute ischemic stroke by initial SPECT.

BACKGROUND AND PURPOSE: Thrombolytic therapy was carried out on patients with acute ischemic stroke, and the risk of hemorrhagic transformation was evaluated from the residual cerebral blood flow (CBF) by pretherapeutic single-photon emission-computed tomography (SPECT). METHODS: Local intra-arterial thrombolytic therapy was carried out using urokinase or recombinant tissue plasminogen activator (rt-PA) within 6 hours from the onset in 34 patients in whom no hypodensity areas were observed on the initial computed tomography examination. In the 20 patients with carotid territory occlusion who underwent 99mTc-labeled hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT, the residual CBF of the ischemic region was evaluated semiquantitatively by calculating two parameters: the ischemic regional activity to cerebellar activity ratio (R/CE ratio) and asymmetry index (AI). RESULTS: The occluded vessels could be recanalized in 22 (92%) of the 24 patients in the urokinase group and in all 10 of the patients in the rt-PA group. Hemorrhagic transformation appeared in 4 patients in the urokinase group and 3 patients in the rt-PA group. Among the 20 patients who underwent SPECT before the treatment, the residual CBF was lower in the 5 patients who developed hemorrhagic transformation than in the 15 who did not (P < .05). Hemorrhagic transformation occurred in all patients with R/CE ratio of less than 0.35 and AI of more than 1.5. CONCLUSIONS: The risk of hemorrhagic transformation after recanalization of occluded vessels by local intra-arterial thrombolytic therapy was considered to be high when the pretherapeutic residual CBF was markedly reduced.

Acute Disease↗

PubMed1994

Surfactant subtypes. In vitro conversion, in vivo function, and effects of serum proteins.

Surfactant in the alveolar space can be separated into heavy and light subtypes by differential centrifugation or on isopyknic sucrose density gradients. The conversion from heavy subtypes to light subtypes occurs in vitro by surface-area cycling. However, the function of light subtypes made by cycling and substances that might influence in vitro conversion have not been evaluated. Therefore, we compared the in vivo function of the heavy and light subtypes isolated from rabbit surfactant and similar density fractions prepared in vitro by surface-area cycling. We then asked if serum, globulin, or albumin would alter the in vitro conversion. The function of surfactant fractions was studied in vivo by treating surfactant-deficient 27 d gestational age preterm rabbits with 50 mg/kg of heavy or light subtype surfactant. Dynamic compliance values and lung volumes from PV curve measurements showed that heavy subtypes had superior in vivo function compared with light subtypes independent of in vivo or in vitro sources (p < 0.01). Light subtypes prepared in vitro lost surfactant function and were similar to in vivo light forms. When serum proteins were added to the heavy subtype surfactant, the conversion rate from heavy to light subtypes was accelerated. Serum accelerated conversion more than globulin, and the serine proteinase inhibitor diisopropylfluorophosphate blocked the conversion. Albumin had no significant effect. The increased rate of conversion caused by serum identifies a new mechanism for surfactant inactivation that could occur with lung injuries associated with increased alveolar protein.

Animals↗

PubMed1994

In vivo function of surfactants containing phosphatidylcholine analogs.

Increased phospholipase A2 activity demonstrated in some forms of lung injury may contribute to surfactant dysfunction. Phospholipase A2-resistant analogs of dipalmitoylphosphatidylcholine (DPPC) with surfactant properties might therefore be useful lipid components of treatment surfactants for certain lung injuries. The in vivo function of surfactants containing DPPC or the phospholipase-resistant analogs dihexadecylphosphatidylcholine (DEPC) or dihexadecylphosphonotidylcholine (DEPnC), with or without surfactant proteins B and C (SP-B+C), was thus evaluated in preterm rabbits (27 days' gestation). Rabbits randomly received one of seven surfactants (DPPC, DEPC, DEPnC, DPPC+SP-B+C, DEPC+SP-B+C, DEPnC+SP-B+C, or lipid extract surfactant [LES]) or 0.45% NaCl (control) and were ventilated for 30 min. Lipid-only surfactants decreased ventilatory pressures (peak inspiratory pressures minus positive end-expiratory pressure) relative to control (p < 0.05). Addition of SP-B+C further decreased ventilatory pressures to levels similar to LES (p < 0.01 versus control, lipid-only surfactants). Lung dynamic compliances and postventilation pressure-volume curves improved in the following order: LES, SP-B+C lipid surfactants > lipid-only surfactants > control (p < 0.05). All surfactant preparations decreased intravascular 125I-albumin recoveries in the lungs relative to control (p < 0.01 for all surfactants versus control). These results indicate that DEPC and DEPnC were as effective as DPPC as lipid components of synthetic surfactants. And like DPPC, the analogs interacted with isolated SP-B+C and improved in vivo function to levels comparable to LES.

Animals↗

PubMed1994

Surfactant protein A labeling kinetics in newborn and adult rabbits.

Surfactant protein A (SP-A), the major hydrophilic protein specifically associated with surfactant, has multiple metabolic and host defense functions as well as primary surfactant biophysical functions in association with the other surfactant proteins and lipids. To characterize its kinetics of secretion and clearance from the airspace, we measured specific activity-time curves for alveolar and lamellar body associated SP-A following the intravascular and/or intratracheal administration of the radiolabeled precursors Tran 35S-label containing primarily methionine and cysteine or [3H]methionine to newborn and adult rabbits. Alveolar SP-A specific activity peaked 30 min after precursor injection in both newborn and adult rabbits, and labeled SP-A was not detected in lamellar bodies until after 2 h. In newborns, a second peak of labeled SP-A appeared at 15 h. In both newborns and adult rabbits, lamellar body specific activity-time curves were most consistent with SP-A entering lamellar bodies via a recycling pathway from the airspaces. The airspace clearance of SP-A in adult rabbits had a biologic half-life of about 4.5 h. There was very little decrease in SP-A specific activity in the newborn rabbits, indicating minimal catabolism. These studies demonstrate secretion of endogenously synthesized SP-A by a pathway separate from lamellar bodies. The kinetics of secretion of SP-A and the surfactant phospholipid in newborn and adult rabbits indicate separate metabolic pathways.

Animals↗

PubMed1994

Absolute stereostructures of hydramacrosides A and B, new bioactive secoiridoid glucoside complexes from the leaves of Hydrangea macrophylla Seringe var. thunbergii Makino.

Two new bioactive secoiridoid glucoside complexes named hydramacrosides A and B were isolated from the leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO. The absolute stereostructures of hydramacrosides A and B were elucidated on the basis of chemical and physicochemical evidence which included the application of the 13C NMR glycosylation shift rule of 1, 1'-disaccharides and the modified Mosher's method. Hydramacrosides A and B exhibited inhibitory effect on the histamine release from rat mast cells induced by antigen-antibody reaction.

Animals↗

PubMed1994

Studies on chemical modification of monensin. V. Synthesis, sodium ion permeability, antibacterial activity, and crystal structure of 7-O-(4-substituted benzyl)monensins.

7-O-(4-Substituted benzyl)monensins (3a-g) were synthesized from monensin (1), and their lipophilicity, antibacterial activity, and Na+ ion permeability were examined. 7-O-(4-Ethylbenzyl)monensin (3e) showed the largest Na+ ion permeability, but 3c,f,g showed smaller Na+ ion permeability than 7-O-benzylmonensin (2) in spite of higher lipophilicity. An X-ray study of the sodium salt of 3e revealed that the benzyl group was located over the position between the D and E rings, and that the ethyl substituent on the benzyl group was close to the C(28) methyl group on the E ring.

Anti-Bacterial Agents↗

PubMed1994

Substrate specificity of tRNA (adenine-1-)-methyltransferase from Thermus thermophilus HB27.

tRNA (adenine-1-)-methyltransferase was purified to homogeneity from an extreme thermophile, Thermus thermophilus HB27, by several steps of column chromatographies. The molecular weight of this enzyme was about 60,000 as analyzed by SDS polyacrylamide gel electrophoresis. Km for E. coli tRNA(2Glu) was 100 nM and that for the methyl group donor, S-adenosyl-L-methionine, was 7.8 microM. The substrate specificity of the enzyme was investigated by using T7 RNA polymerase transcripts and tRNA fragments obtained by partial digestion with RNases. The enzyme was able to transfer the methyl group to the 3'-half fragment of E. coli initiator tRNA, however, the extent of methylation was elevated by more than five times when the 5'-half fragment was added and annealed to the 3'-half. This indicates that the main recognition site of the enzyme is within the 3'-half region of tRNA molecule, while the tertiary interaction between the T-loop and the D-loop is very effective for the adequate methylation reaction.

Base Sequence↗

PubMed1994

Progression of bone disease without deterioration of hematological parameters in a child with Gaucher disease during low-dose glucocerebrosidase therapy.

Gaucher disease is the most prevalent lysosomal storage disease. Although the efficacy of the macrophage-targeted human placental glucocerebrosidase is well known, it is still difficult to develop definitive guidelines regarding the appropriate therapy schedule. We describe an 8-year-old Japanese boy with Gaucher disease who had avascular necrosis of the right femoral head without deterioration of hematological variables during low-dose enzyme replacement therapy (12-13 IU/kg). This case demonstrates that continuous normal hematological findings may not preclude progression of other aspects of Gaucher disease in some patients during enzyme replacement therapy.

Blood Cell Count↗

PubMed1994

Improvement of urinary delta-aminolevulinic acid determination by HPLC and fluorescence detection using condensing reaction with acetylacetone and formaldehyde.

We improved the method for determining urinary delta-aminolevulinic acid (ALA) by HPLC-fluorometer after pre-column derivatization with acetylacetone and formaldehyde, and a stable ALA derivative was obtained without any effect from various urinary components as demonstrated by the complete recovery of ALA (100.9 +/- 5.5%, n = 85) from the urine samples. The modified procedure was as follows: Twenty microliters of urine sample, 5 ml of acetylacetone solution (acetylacetone/ethanol/distilled water containing 4 milligrams of NaCl; 15/10/75), and 0.45 ml of 9.3% formaldehyde solution were mixed and boiled for 15 min. The fluorescent derivative of ALA was separated and analyzed by HPLC with the fluorometer at Ex 246 nm and Em 458 nm. Using a gradient program, the retention time of the ALA derivative was 7.3 min and the analysis could be repeated at 13 min intervals. Concentrations of ALA in urine samples measured by this method were significantly correlated with those measured by the Mauzerall-Granick (M-G) method (n = 85, r = 0.993, p < 0.001). The values obtained by our method were, however, lower than those obtained by the M-G method. Urinary ALA concentrations of 40 non-lead workers ranged from 0.1 to 2.3 mg/g creatinine with the mean +/- SD of 1.1 +/- 0.4 mg/g creatinine as measured by the present method.

Adult↗

PubMed1994

[Ratings of perceived exertion in a group of children while swimming at different temperatures].

The purpose of this study was to compare the Ratings of Perceived Exertion (RPE) in children while swimming at different temperatures. Five healthy male swimmers, aged 10 to 12, swam tethered using the breast stroke at 32 degrees C, 25 degrees C and 20 degrees C water temperature in a flume, and biked at 25 degrees C air temperature in contrast with swimming. In swimming, the resistance started at 1.0 kg and increased in 1.0 kg increments up to the point of exhaustion, and in bicycling, started at 0.5 kp with 60 rpm and increased in 0.5 kp increments, respectively. The subjects swam or biked for 5 min during each period, with a rest of 10 to 20 min until they had returned to their resting HR level. The last exercise intensity was for 5 min with the maximal weight the subjects could support. The last min of VO2 and 30 sec of HR were measured during each exercise period. The subjects gave their RPE assessment at the end of each exercise. The relationships between %VO2max and HR were linear with a high correlation coefficient (r = 0.995-0.998) in both water and air. However, the slope of the %VO2max-HR line tended to shift to the right in colder water. Increased VO2 of swimming in cold water was largely attributed to shivering. The RPE increased exponentially against %VO2max in both water and air and deviated more from linearity against HR. The RPE in 25 degrees C water was lowest at all submaximal swimming. At maximal swimming, however, the RPE in the four conditions were much the same. It seemed that the RPE responded differently from HR in varying water temperatures.

Child↗

PubMed1994

[13-week oral toxicity study of lactitol (NS-4) in dogs followed by 4-week recovery test].

UNLABELLED: 13-week repeated dose toxicity studies were conducted on lactitol, a hepatic encephalopathy drug. In the experiment I, male and female dogs were orally treated with lactitol at doses of 0, 1.0, 2.5 and 6.25 g/kg/day for 13 weeks, followed by 4 weeks recovery period. In the experiment II, male and female dogs were orally treated with lactitol at doses of 0, 0.25, 0.50 and 1.0 g/kg/day for 13 weeks in order to require the no-toxic dose. RESULTS: 1. Soft stool and diarrhea were observed at the 0.50 g/kg group and above, and vomiting was observed at the 1.0 g/kg group and above. Increased water consumption was observed at the 6.25 g/kg group. No deaths occurred at all groups. 2. In urinalysis, increased urine volume was observed at the 6.25 g/kg group. 3. Blood chemistry showed decreased BUN at the 6.25 g/kg group. 4. There were no drug-related changes in body weight, food consumption, ophthalmological examination, electrocardiography, hematology and pathology. 5. At the end of the recovery period, all these changes observed at the end of the administration period were disappeared. Based on these results, it was considered that the no-toxic dose of lactitol is 0.25 g/kg/day.

Administration, Oral↗

PubMed1994

[52-week oral toxicity study of lactitol (NS-4) in dogs followed by 9-week recovery test].

Five male and 5 female beagle dogs were orally given lactitol, a hepatic encephalopathy drug, for 52 weeks at doses of 0, 0.25, 1.25 or 6.25 g/kg/day. A 9 week recovery test was conducted after the discontinuation of the drug treatment. Soft stool, diarrhea, and vomiting were seen in the 1.25 and 6.25 g/kg groups. In the 6.25 g/kg group, bloody stool and increased water consumption were also observed. Urinalysis showed larger amount of the urine volume in the 6.25 g/kg group. The cecum weight of this group was increased without any morphological changes. There were no drug related effects on survival, body weight gain and food consumption. Electrocardiographic, ophthalmoscopic, hematologic and biochemical examinations failed to show any abnormalities related to the drug treatment. The above mentioned changes were satisfactorily reversible. Based on the results obtained, the NOAEL of this study was suggested to be 0.25 g/kg/day.

Administration, Oral↗

PubMed1994

Dual staining methods for carbohydrates using lectin-gold silver techniques.

Three dual staining methods were established for the histochemical detection of saccharide residues and acidic groupings of carbohydrates in light microscopy. The first method consisted of combined lectin-gold silver (LT-G-S) and alcian blue (AB) pH 1.0 techniques, whereas the second staining technique was composed of LT-G-S and AB pH 2.5 procedures. These two techniques were found to color saccharide residues and acidic groupings of carbohydrates in black and blue shades respectively, which exhibited a high contrast between the both. The third methods, LT1-G-S-LT2-PO-DAB techniques, yielded reaction products of blackish and yellowish brown shades, which represented the localizations of two different saccharide residues in one and the same section. According to the results of the experimental and control procedures, the present three dual staining methods are believed to be reliable, reproducible and unusually useful for light microscopic histochemical studies on acidic and non-acidic carbohydrates.

Animals↗

PubMed1994

HID-AB2.5-PAS and HID-PAS methods for the histochemical analyses of a variety of carbohydrates.

The high iron diamine (HID) staining procedure was combined with alcian blue pH 2.5 (AB2.5) and periodic acid-Schiff (PAS) methods for the simultaneous demonstration of carbohydrates containing sulfate esters, carboxyl groups and oxidizable vicinal diols, whereas it was sequentially employed with PAS alone to differentiate sulfate esters from oxidizable vicinal diols. A variety of rat tissues and the epidermis of four fish species were utilized to test the specificity or selectivity of these methods. The HID-AB2.5-PAS sequence largely coloured carbohydrates containing sulfate esters, carboxyl groups and oxidizable vicinal diols in brownish black, turquoise and magenta shades respectively. The HID-PAS sequence coloured sulfate esters brownish black and oxidizable vicinal diols magenta. On the basis of the experimental and control studies on the both staining techniques, these staining methods could be postulated to represent efficient and useful techniques for precise histochemical analyses and simultaneous differentiations of a variety of carbohydrates in light microscopy.

Alcian Blue↗

PubMed1994

Effects of iodine pretreatment of sections upon immunogold-silver staining in light microscopic immunohistochemistry.

Effects of Lugol's iodine pretreatment upon immunogold-silver staining were examined in terms of the intensification of the reaction products obtained by physical development. Iodine pretreatment has diminished the duration necessary for the development, whereas the staining reaction of an appropriate intensity, could hardly be obtained by the pretreatment. In addition, essential staining reactions tended to be accompanied by marked nonspecific silver precipitations. It is concluded that iodine pretreatment should either be omitted or used with cautions in immunogold-silver staining procedures for the precise detection of antigenic sites.

Animals↗

PubMed1994

The use of periodic acid-thiocarbohydrazide-silver protein-physical development (PA-TCH-SP-PD) procedure for the histochemical detection of neutral carbohydrates in the circumventricular organs of the rat.

A periodic acid-thiocarbohydrazide-silver protein-physical development (PA-TCH-SP-PD) procedure was applied to the rat circumventricular organs (CVOs), which are known to be specialized structures in the brain. In the rat CVOs, vivid PA-TCH-SP-PD reactions were obtained in the apical surface and cytoplasm of the ependymal cells of the subcommissural organ (SCO) and the epithelial cells in the choroid plexuses (CPs) examined, and similar positive reactions were detected in the vascular walls and perivascular connective tissues in all the CVOs tested. Further, varying intensities of PA-TCH-SP-PD reactions were noted in the neuronal and glial networks of the organum vasculosum laminae terminalis (OVLT), subfornical organ (SFO) and area postrema (AP). The results obtained in the present study indicate that in the rat CVOs the histologic structures mentioned contain varying amounts of neutral carbohydrates and possible histophysiological significances of these carbohydrates in these organs have been discussed with references to their functions.

Animals↗