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Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 793 records · Page 44Linked to original sources
PubMed1990

Clinical assessment of therapeutic effects on cancer using 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography: preliminary study of lung cancer.

Using positron emission tomography, we studied the tumor uptake of 18F-2-fluoro-2-deoxy-D-glucose (18FDG) in five lung cancer patients before and after anti-cancer therapy (radiotherapy and/or chemotherapy). The tumor uptake of 18FDG was classified as positive and negative; the former, by increasing the uptake of 18FDG with time, and the latter, by decreasing or the constant uptake of 18FDG. Before therapy, all cases tested positive. After therapy, three cases were negative and two cases remained positive. All negative cases corresponded to complete second 18FDG study. Our findings in the 18FDG study correlate with the clinical results. 18FDG is a promising method for assessing therapeutic effects on cancer clinically.

Adult↗
PubMed1990

Fraction size-dependent acute skin reaction of mice after multiple twice-a-day doses.

To study the effect of multiple daily fractions on acute murine foot reaction, the left feet of C3Hf/Sed mice were irradiated by a Cs-137 irradiator at intervals of 6 and 18 hr, alternately. Fraction sizes ranged from 1 to 12 Gy, and various numbers of fractions were given. At the end of fractionation, a top-up dose of 20 Gy was administered. The overall treatment time ranged from 2 to 21 days. The average skin reaction from 10 to 35 days after completion of irradiations was determined. The skin reactions started from 8 to 27 days following the completion of irradiations. The skin reaction after fraction sizes of 3.5 and 5 Gy was dependent on the total dose. The skin reaction after fraction sizes of 1.5 and 2 Gy showed a biphasic response; at lower total doses, the skin reaction was proportional to the total dose, but at higher total dose, the skin reaction reached a plateau. The average skin reaction at the plateau with fraction sizes of 1, 1.5, and 2 Gy were 0.79 +/- 0.03, 1.12 +/- 0.13, and 1.37 +/- 0.06, respectively. The alpha/beta ratio for acute skin reaction following the twice a day scheme was 9.09 Gy (at dose/fraction greater than or equal to 3.5 Gy). The plateau may be attributed to the effect of accelerated proliferation and a balance between cell depletion and proliferation during twice-a-day irradiations. It is also suggested that twice-a-day irradiations induce more proliferation in skin than once a day treatments.

Animals↗
PubMed1990

Percutaneous fiberoptic spinal laser endoscopy.

For percutaneous observation of lesions near the spinal cord and percutaneous spinal laser surgery under the visual field, we studied a method and approach to the spinal cord and intraspinal surgical procedures with laser using a newly developed, small-diameter laser endoscope. The subarachnoid and epidural spaces of a goat were punctured using a 17-gauge epidural needle, and the endoscope (diameter 0.7 mm) was inserted through the needle. The spinal cord and surrounding tissue were observed. Next, an endoscope (diameter 1.5 mm) was inserted into the subarachnoid space, and the quality of the picture and manageability of the endoscope were examined. The Xe:Cl excimer laser was irradiated to a nerve root through a 0.4 mm optical fiber for laser transmission through this endoscope. The spinal cord, nerve roots, and arachnoid were clearly observed through this endoscope. The pulsation of the artery accompanying a root was seen clearly, and the quality of the picture of the endoscope was thought to be sufficient for diagnosis. The nerve root was cut within 30 seconds by excimer laser, and the possibility of laser surgery was demonstrated. Although it was shown that this endoscope could be a useful diagnostic and therapeutic tool, improvement in the manageability of the tip of the endoscope was considered to be important for a clinically usable endoscope.

Animals↗
PubMed1990

Purification and characterization of NADPH-dependent methemoglobin reductase from the nucleated erythrocytes of bullfrog, Rana catesbeiana.

Two protein components having a NADPH-dependent methemoglobin reductase activity were purified to electrophoretic homogeneity from the erythrocytes of the bullfrog, Rana catesbeiana. Their molecular properties were investigated. The components were separated by isoelectric focusing, having discrete bands of pI 5.0 and 7.5, respectively. The pI 5.0 component, designated F-5.0, was faint yellow, with a broad absorption in the range of 400-450 nm, while the pI 7.5 component, designated F-7.5, was colorless and did not absorb in that range. The molecular weight was estimated to be 22,000 for both components by gel filtration and SDS-PAGE. When F-5.0 was subjected to isoelectric focusing repeatedly, the protein part of that component gradually moved to and refocused at pH 7.5, leaving a yellow color at acidic pH. Both F-5.0 and F-7.5 were highly specific for NADPH and had the same kinetic properties in catalyzing the reduction of MB, DCPIP, FMN, or FAD, and that of methemoglobin or cytochrome c in the presence of a certain dye. They were also indistinguishable from one another in their amino acid compositions and were completely identical in the N-terminal sequence of 24 amino acid residues. These findings strongly suggest that the two components can be attributed to the same enzyme molecule, carrying an identical protein moiety but interacting differently with some unidentified biological pigments, and that they are equivalent in their molecular and kinetic properties to the NADPH-dependent enzyme(s) occurring in human erythrocytes.

Amino Acid Sequence↗
PubMed1990

Pharmacokinetics and antihypertensive effects of lisinopril in hypertensive patients with normal and impaired renal function.

The antihypertensive effects and pharmacokinetic properties of lisinopril, an angiotensin-converting enzyme (ACE) inhibitor, were investigated in hypertensive patients with normal renal function (NRF, mean serum creatinine 1.0 mg/dl, n = 9) and those with impaired renal function (IRF, mean serum creatinine 1.7 mg/dl, n = 8). Lisinopril was administered orally (10-mg dose once daily for 5 or 8 days). Measurement of blood pressure (BP) and sampling of blood specimens were made on the first and last days of treatment. During consecutive dosing of lisinopril, its antihypertensive effects were sustained for greater than or equal to 12 h with less diurnal variation of BP. Serum ACE activity was markedly suppressed for 24 h. Plasma levels of lisinopril in the IRF group were higher than those in NRF with significant differences in the peak levels and areas under the plasma concentration time curve (AUC). A significant inverse correlation was found between the creatinine clearance and the AUC for lisinopril. These results suggest that lisinopril has a long-lasting action and that it is a useful antihypertensive agent for controlling BP in patients with either NRF or mild IRF. When administered for an extended period, however, more careful consideration should be given to the dose in patients with IRF than in patients with NRF to minimize the possibility of untoward side effects.

Adult↗
PubMed1990

The system and procedures of percutaneous intradiscal laser nucleotomy.

Since 1986, percutaneous intradiscal laser nucleotomy (PILN) has been studied in the authors' laser laboratory. The purpose of this report is to develop PILN as an alternative to chemonucleolysis and percutaneous discectomy, which are currently applied, and to establish a safe, easy, accurate and short-time therapy method for lumbar disc herniation. After laser irradiation, intradiscal pressures (IDP) decreased and the nucleus pulposus was gradually replaced with cartilaginous fibrous tissue. The evaluation of heat distribution with thermocouples and thermography was done to determine safe optimum irradiating conditions and to develop a new double-lumen needle and a bare quartz fiber. Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser devices have been improved for easy and safe use, and a new tip type pressure transducer has been made for improved therapeutic results using this new method.

Animals↗
PubMed1990

Primary cutaneous adenoid cystic carcinoma: ultrastructural study and immunolocalization of types I, III, IV, V collagens and laminin.

A primary adenoid cystic carcinoma of the skin is reported. Light microscopy revealed pseudocysts. PAS-positive basement membrane and true glandular lumen, which in aggregates are specific for adenoid cystic carcinoma. Perineural invasion was also observed. Ultrastructural examinations revealed three types of cystic spaces; pseudocysts, true glandular lumens and intercellular spaces. Enzyme histochemical examinations showed positive reactions for eccrine enzymes, including phosphorylase and succinic dehydrogenase and negative for apocrine enzymes. Immunolocalization of collagens and laminin revealed that basement membranes of the pseudocysts involve Type V collagen as well as Type IV collagen and laminin.

Aged↗
PubMed1990

Regulation of liver angiotensinogen and kidney renin mRNA levels by angiotensin II.

The current study was designed to evaluate the role of angiotesin II (ANG II) in the regulation of renin mRNA and angiotensinogen mRNA levels. We investigated the changes in renin mRNA levels in the kidney and angiotensinogen mRNA levels in the liver induced by ANG II infusion and by inhibition of the endogenous renin-angiotensin system with enalapril or saralasin in rats. mRNAs for angiotensinogen and renin were measured by densitometric analysis of Northern blot hybridization. After a 4-h intravenous infusion of ANG II (0.2 micrograms.kg-1.min-1), angiotensinogen mRNA level in the liver increased 2.5-fold to the control level, and renin mRNA level in the kidney decreased by 45%. Four hours after treatment with a single dose of enalapril (3 mg/kg po), angiotensinogen mRNA level in the liver decreased by 50%, and renin mRNA level in the kidney increased 1.5-fold to the control level. These mRNA levels returned to control levels 8 h after treatment. After a 4-h infusion of saralasin (2.5 micrograms.kg-1.min-1) in the low-sodium state, angiotensinogen mRNA level in the liver decreased by 45%, and renin mRNA level in the kidney increased twofold to the control level. These findings suggest that ANG II is one of the factors that regulate angiotensinogen mRNA level in the liver and renin mRNA level in the kidney.

Angiotensin II↗
PubMed1990

Elevated angiotensinogen mRNA levels in rat liver by nephrectomy.

The expression of the angiotensinogen gene was studied in nephrectomized rats with and without adrenal glands. Angiotensinogen mRNA was measured by a sensitive radiodensitometric hybridization assay. Angiotensinogen mRNA levels in the liver increased 5 times by nephrectomy alone and 2.6 times by nephrectomy with adrenalectomy in acute experiments. Brain mRNA levels remained the same in both groups. When nephrectomy was performed 7 days after adrenalectomy, mRNA level increased by 50%. Angiotensinogen mRNA increased 5 times in the liver and 2.3 times in the brain by the administration of dexamethasone. An additive effect on liver angiotensinogen mRNA level was observed in nephrectomy with dexamethasone treatment. These results suggest that in nephrectomy, a synergetic action of glucocorticoids and other unknown factors increase hepatic angiotensinogen mRNA levels.

Adrenalectomy↗
PubMed1990

A method for histochemical demonstration of protein-bound amino groups by light microscopy.

We have established an efficient method for the histochemical demonstration of protein-bound amino groups by light microscopy, using a ninhydrin or alloxan-thiocarbohydrazide-silver proteinate (NHY or ALX-TCH-SP) sequence followed by a physical development (PD) procedure. As a result of the present experimental studies on Carnoy's solution-fixed paraffin sections of a series of rat tissues, including three types of major salivary glands, liver, pancreas, stomach, duodenum, jejunum, colon, kidney, prostate, and spleen, the sensitivity and specificity of the new method were found to be sufficient. In the tissues tested, protein-bound amino groups were visualized by distinct brownish or blackish reaction products. Comparisons of the particular method with the NHY or ALX-Schiff methods employed hitherto have substantiated the fact that the former method leads to apparently higher visibility of reaction products than the latter.

Alloxan↗
PubMed1990

Detection of serum antibody by the antimitogen assay against streptococcal erythrogenic toxins. Age distribution in children and the relation to Kawasaki disease.

We describe a new method to measure human serum antibody against streptococcal erythrogenic toxins that uses inhibition of lymphocyte mitogenicity of the toxins as the indicator. Sera from 53% of 53 Kawasaki disease patients contained specific inhibitory activity against A toxin, whereas only 15% had serum inhibitory activity against B toxin. The specific anti-A toxin serum inhibitor was found in 10% of 118 age-matched control patients suffering from various infections and allergic diseases (p = 0.001, compared to Kawasaki disease patients). Serum inhibitory activity was detected in a small number of patients with beta-hemolytic streptococcal infection (3/19) and in none of the age-matched healthy children (0/17). However, four of seven cord blood sera samples and five of 13 sera samples from healthy neonates contained the inhibitor, a result suggesting passive transfer from mothers. Most of the antimitogen-positive sera were also positive by ELISA of IgG antibody against A toxin, and IgG fractions of the positive sera remained positive in both assays. Thus, it is possible that the specific serum inhibitor detected by the antimitogen assay represents anti-A toxin antibody. The role of toxin-producing bacteria in the pathogenesis of Kawasaki disease remains to be investigated.

Antibodies, Bacterial↗
PubMed1990

High concentrations of plasma immunoreactive inhibin during normal pregnancy in women.

The plasma inhibin concentrations in 190 normal pregnant women at 5-40 weeks gestation and in 4 puerperal women were measured by a specific RIA for human inhibin. The average plasma inhibin concentrations in pregnant women throughout pregnancy (minimum, 2.25 +/- 0.48 IU/mL at 17 weeks gestation; maximum, 24.15 +/- 6.99 IU/mL at 39 weeks gestation) were much higher than those in nonpregnant women with a normal menstrual cycle (0.46 +/- 0.04 IU/mL in the midfollicular phase and 2.02 +/- 0.47 IU/mL in the midluteal phase). The inhibin concentrations were already high at 5 weeks gestation (7.54 +/- 1.10 IU/mL) and rose to peak at 8-10 weeks gestation. The concentrations then decreased and remained relatively low during 14-30 weeks gestation, but rose again during the third trimester. The inhibin concentrations decreased to undetectable levels after delivery. Immunoreactive inhibin was demonstrated in the corpus luteum and term placental extracts, and the dose-response curves were parallel to an inhibin preparation from human follicular fluid. Immunoreactive inhibin concentrations were also high in both the umbilical vein and artery (7.77 +/- 0.80 and 7.84 +/- 0.78 IU/mL, respectively). These observations suggest that both the corpus luteum and placenta are likely sources of inhibin.

Adult↗
PubMed1990

[Effects of betaxolol, a cardioselective beta-adrenoceptor antagonist, on ischemic myocardial energy and carbohydrate metabolism in dogs].

The effect of betaxolol, a beta 1-adrenoceptor antagonist, on ischemic myocardial metabolism was studied in dog hearts subjected to an occlusion of the left anterior descending coronary artery for 10 or 30 min. Betaxolol (0.1 or 0.3 mg/kg) was injected i.v. 5 min before ischemia. Betaxolol decreased heart rate, (+)dp/dt, coronary flow and blood pressure. Coronary occlusion decreased the levels of creatine phosphate, adenosine triphosphate, total adenine nucleotides and energy charge potential in the ischemic myocardium. Ten minutes after ischemia, betaxolol significantly diminished these impairments of energy metabolism. Even 30 min after ischemia, a higher dose of betaxolol significantly inhibited the depletion of total adenine nucleotides. Myocardial ischemia produced a breakdown of glycogen, an accumulation of lactate and an inhibition of glycolytic flux through the phosphofructokinase reaction. Betaxolol also reduced these alterations of carbohydrate metabolism 10 min after ischemia. These results indicate that betaxolol delays the onset of myocardial metabolic change from aerobic to anaerobic during ischemia and hence reduces the severity of myocardial ischemic injury.

Adenine Nucleotides↗
PubMed1990

Effects of thyroid hormone on angiotensinogen and renin messenger RNA levels in rats.

We studied the expression of angiotensinogen and renin genes in rats treated with 3,3',5-triiodo-L-thyronine (T3) at doses of 0.1 and 1 mg/kg of body weight. Liver angiotensinogen mRNA increased by 2 to 3 times 8 to 12 hours after T3-treatment. This increase was dose-related. Plasma angiotensinogen concentration (PAC) increased 12 hours after T3-treatment. Brain and renal angiotensinogen mRNA levels and the renal renin mRNA level remained the same throughout the experimental periods. These results suggest that the thyroid hormone initially increases angiotensinogen mRNA and leads to an increase in the production of angiotensinogen in the liver followed by an elevation of PAC.

Angiotensinogen↗
PubMed1990

Betaxolol, a cardioselective beta-adrenoceptor antagonist, attenuates ischemic myocardial acidosis in dogs.

The effects of betaxolol, a cardioselective beta-adrenoceptor antagonist, on ischemic myocardial acidosis were studied in dog hearts, in which the left anterior descending coronary artery was partially occluded for 90 min, and were compared with those of atenolol and propranolol. Myocardial ischemia produced a decrease in myocardial pH (measured by a micro glass pH electrode) and an elevation of the ST segment of epicardial ECG (assessed by a surface electrode). Betaxolol (0.01, 0.03 or 0.1 mg/kg), atenolol (0.03 or 0.1 mg/kg) or propranolol (0.03 or 0.1 mg/kg), when injected i.v. 30 min after ischemia, restored myocardial pH and the ST segment of ECG that had been altered by partial occlusion. However, the effect of betaxolol on myocardial acidosis was more potent than that of atenolol or propranolol. The decrease in (+)dp/dt by betaxolol (0.03 mg/kg) was less potent than that by atenolol (0.1 mg/kg) and equivalent to that by propranolol (0.1 mg/kg), although the restorations of myocardial acidosis by the drugs were almost equivalent. These results have confirmed that beta-adrenoceptor antagonists attenuate the ischemia-induced myocardial acidosis and have shown that among three beta-adrenoceptor antagonists, betaxolol is the most effective in improving myocardial acidosis with a relatively weak effect on myocardial contractile function.

Acidosis↗
PubMed1990

Intrarenal vascular sites of action of adenosine and glucagon.

Our purpose was to localize the intrarenal vascular sites of action of adenosine and glucagon. Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured in anesthetized dogs, and renal perfusion pressure (RPP) was varied by an adjustable aortic clamp. At normal RPP, RBF was increased by all agents. In contrast, GFR was increased by glucagon, decreased by adenosine and unchanged by acetylcholine (ACh) or adenosine plus glucagon. The increases in RBF by glucagon occurred only at RPPs within the autoregulatory pressure range, and renal autoregulatory capability was attenuated during the infusion of glucagon. In contrast, adenosine increased RBF at RPPs both within and below the autoregulatory pressure range, and the autoregulatory capability was not perceptibly impaired. Superimposition of glucagon to adenosine caused further vasodilation, and the autoregulatory efficiency was completely attenuated. There was no difference between the RPP-RBF or RPP-GFR relations obtained during infusion of adenosine plus glucagon and ACh, which dilates both the afferent and efferent arterioles. It is generally accepted that afferent arteriolar resistance attains a minimum value at RPP near the lower limit of the autoregulatory range. Thus, our data indicate that glucagon and adenosine preferentially dilate the afferent arteriole and the efferent arteriole, respectively.

Adenosine↗