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Biomedical subjects

Y Kitamoto

Publications and source records attributed to Y Kitamoto.

At least 37 records · Page 2Linked to original sources
PubMed1993

Flow cytometric analysis of hematuria using fluorescent antihemoglobin antibody.

To identify the morphological changes of urinary erythrocytes in hematuria objectively, flow cytometrical analysis of fluorescence-labeled erythrocytes was performed. Fifty-one fresh urine samples from 33 hematuric patients (16 with glomerulonephritis and 17 with urological disease) were obtained. Urine erythrocytes were stained with FITC-labeled antihemoglobin antibody, and distinguished from other particles with similar size. Forward scattered light intensity (FW-SC) was used as an indicator of red cell size and right orthogonally scattered light intensity (RT-SC) divided by forward scattering (RT-SC/FW-SC) was used as a marker of cell surface irregularity. The size of erythrocytes expressed by FW-SC was significantly smaller in glomerulonephritic hematuria (101.6 +/- 41.8) than that in urological hematuria (123.5 +/- 44.7). RT-SC/FW-SC was smaller in urological hematuria (1.22 +/- 0.18) in comparison with glomerulonephritic hematuria (1.33 +/- 0.12). These results suggest that erythrocytes in glomerulonephritic hematuria had smaller size and more complex surface structure in comparison with urological hematuria. When cutoff was set at 110 of FW-SC for the criteria of glomerulonephritic erythrocytes, a correct diagnosis was made in 73.3% (22/30) of glomerulonephritic hematuria and in 76.2% (16/21) of nonglomerular hematuria. We clarified more complex morphological changes of glomerulonephritic urinary erythrocytes objectively.

Adolescent↗
PubMed1992

Dermal patch anesthesia: pain-free puncture of blood access in hemodialysis patients.

Clinical application of dermal patch anesthesia to relieve pain at venous cannulation of blood-access was studied in hemodialysis patients. Aqueous gel of 10% lidocaine base with 3% glycyrrhetinic acid monohemiphthalate disodium (GA MHPh 2Na) was applied for 60 minutes to the skin of the patients. Degree of pain was expressed as a pain score. Analgesic effect of the lidocaine gel was evaluated in 16 patients in a placebo-controlled, double-blind, cross-over design by comparing the gel with lidocaine with a placebo gel without lidocaine. The mean pin-prick pain score (1.0 +/- 0.5) in the lidocaine gel patch (n = 16) was significantly lower than that (2.3 +/- 0.3) in the placebo gel patch (P < 0.01). In 8.8% of the patients, blood pressure was elevated after venous cannulation, but this tendency was modified by dermal patch anesthesia with the lidocaine gel. Plasma concentration of lidocaine was under the detection limit of assay (< 0.05 micrograms/mL) after dermal patch anesthesia in six subsequent dialysis treatments.

Administration, Cutaneous↗
PubMed1992

The mechanism of glomerular dysmorphic red cell formation in the kidney.

The mechanism of glomerular dysmorphic cell formation was studied in a in vitro system simulating the process of concentrated acidic urine formation along the nephron. Red cells suspended in phosphate buffer were exposed to three sequential pH gradients, (1) pH 7.4-6.6, (2) pH 6.6-6.5, and (3) pH 6.5-5.2, accompanying osmolality gradients, (1) 280-1200 mOsm/kg H2O, (2) 1,200-140 mOsm/kg H2O, and (3) 140-1,100 mOsm/kg H2O, respectively, for 15 to 60 min, and red cell shapes were observed by differential interference microscopy. The appearance rate of glomerular dysmorphic cells was 37.7 to 47.1% after finishing all the gradients. The last gradient, simulating the work of the collecting duct, was essential for the dysmorphic cell formation; maximal formation was at the final pH of 5.0 and osmolality of 1,000 mOsm/kg H2O. No dysmorphic cells were observed in gradients simulating alkaline or diluted urine formation. In 10 glomerulonephritic patients, glomerular dysmorphic cells appeared over five times as frequently in concentrated acidic urine as in alkaline or diluted urine. Results of in vitro and patient studies coincided well with each other, suggesting that in glomerulonephritic patients, dysmorphic cells might be produced while red cells are passing through the tubules, where concentrated acidic urine is formed.

Erythrocytes, Abnormal↗
PubMed1992

Cytomegalovirus infection associated with acute pancreatitis, rhabdomyolysis and renal failure.

The occurrence of rhabdomyolysis and acute renal failure associated with cytomegaloviral infection is rare. A 27-year-old housewife was admitted to our hospital with complaints of thirst, muscle weakness, abdominal pain and oliguria. There was no past history of diabetes, drinking, fever or drug habituation and a negative family history. Laboratory tests revealed myoglobinuria, hyper-pancreatic type amylaseuria, hyperglycemia, azotemia and highly increased creatine phosphokinase in the plasma. She was treated with hemodialysis and insulin therapy. Serological studies showed a 4-fold increase in cytomegalovirus antibody titers 4 weeks after admission. Muscle biopsy specimens showed hyaline degeneration and infiltration of T cell lymphocytes in the muscle. Renal biopsy specimens showed acute tubular necrosis and some myoglobin casts. No cytomegalovirus antigen was found in renal specimens by immunofluorescence study. From these results, it was determined that a systemic cytomegalovirus infection triggered pancreatitis which caused diabetic ketoacidosis, rhabdomyolysis and acute renal failure.

Acute Disease↗
PubMed1992

A new morphological classification of urinary erythrocytes for differential diagnosis of glomerular hematuria.

A new morphological classification of urinary erythrocytes was instituted in order to differentiate glomerular from urological hematuria. One hundred and thirteen hematuric patients including 73 glomerular and 40 urological disease patients were examined. The former group consisted of IgA nephropathy (n = 45), lupus nephritis (6), membrano-proliferative glomerulonephritis (5), non-IgA mesangial proliferative glomerulonephritis (4), Henoch-Schoenlein purpura nephritis (4), membranous nephropathy (4), endocapillary proliferative glomerulonephritis (3), and minimal change nephrotic syndrome (2). The latter group included bladder cancer (n = 15), renal calculi (15), prostate cancer (3), urethral cancer (1) and post-transurethral resection (6). In each urine sample, 100 urinary erythrocytes were observed under differential interference microscopy and classified into 10 concretely defined shapes (5 "glomerular" and 5 "urological" shapes) and unclassified shapes. Using percentage of "glomerular" shape erythrocytes and setting the cut-off at 15%, 90.4% of sensitivity and 97.5% of specificity for the diagnosis of glomerular disease were obtained. When percentage of one specific shape (G1), [i.e. doughnut-like cell with one or more blebs] was used at a cut-off of 1%, sensitivity and specificity were 89.0% and 95.0% respectively. These results were satisfactory as compared with most previous reports. Moreover, our classification is so concrete that it is more objective, accurate, and easily understandable, even for beginners. Distinct shape "G1" is particularly important for morphological investigation of hematuria.

Diagnosis, Differential↗
PubMed1991

Antithrombotic mechanisms of urokinase immobilized polyurethane.

Urokinase immobilized polymer is highly antithrombotic, which cannot be explained only by fibrinolysis. We immobilized 10 IU/cm2 of urokinase to polyurethane by using maleic anhydride methylvinyl ether copolymer as a carrier. Then we incubated blood in circular tubes made of this material, measured the clotting factors and observed the surface of the tubes after incubation by scanning electronmicroscopy and immunofluorescence microscopy. After 5 min incubation, the relative activities of factors V, VIII, IX, X and XII, fibrinogen, plasminogen and alpha 2 plasmin inhibitor decreased, but the activity of factor VII increased. No platelet adhesion to the surface of the urokinase immobilized polyurethane was observed and there was no significant adsorption of serum proteins, including fibrinogen, fibronectin and vWF antigen, on the surface. Urokinase-immobilized polyurethane catalyzed the digestion of clotting factors as well as fibrinolysis and also inhibited platelet adhesion on its surface probably by inhibiting protein adsorption and its clinical application including vessel prosthesis should be developed further.

Blood Coagulation Factors↗
PubMed1991

A possible contribution of endogenous atrial natriuretic peptide to proteinuria in patients with chronic renal failure.

Plasma levels of immunoreactive atrial natriuretic peptide (IR-ANP) were measured with a specific radioimmunoassay in 19 undialysed patients with chronic renal failure. At the beginning, an extremely high level of plasma hANP (50 fmol/ml) seen in a patient was rejected with Smirnov's test and was excluded from further statistics. The plasma IR-ANP levels in these patients were significantly higher than those of 19 normal subjects matched with age and sex (10.9 +/- 1.6 vs 5.3 +/- 0.6 fmol/ml, mean +/- SEM, p less than 0.01), and positively correlated with mean blood pressure (r = 0.44, p less than 0.05) and the cardiothoracic ratio (r = 0.65, p less than 0.01), but did not correlate with creatinine clearance (r = -0.38, n.s.). Further, a significant correlation was observed between plasma IR-ANP and urinary protein output (r = 0.47, p less than 0.05). On the other hand, urinary protein output did not correlate significantly with variables such as mean blood pressure, the cardiothoracic ratio or creatinine clearance. Since it has been suggested that ANP enhances glomerular capillary permeability, increased ANP responding to volume overload in those patients may play an important role in increasing urinary protein excretion.

Adult↗
PubMed1991

[Familial systemic lupus erythematosus in mother and son].

Although the etiology of systemic lupus erythematosus (SLE) is thought to be multifactorial, genetic factors may play some role in its pathogenesis. Supportive of this hypothesis are the studies of identical twins and familial cases of SLE. We describe below a family in which mother and son both developed SLE. The mother was diagnoged as SLE at age 25, and had been treated with prednisolone. In February 1989, she had massive proteinuria. The onset of the son's disease was at age 13 in 1988, when he noted erythema and photosensitivity. At admission to our hospital in 1989, he had polyarthralgia, proteinuria, positive antinuclear antibody, positive anti-DNA antibody. Both two patients had a same haplotype, HLA A2.BW61(40).DR9. Two asymptomatic members of this family were also studied, the younger son had positive antinuclear antibody and hypocomplementemia.

Adolescent↗
PubMed1991

Renal disease in an adult with type 1 glycogen storage disease.

The renal disease in an adult woman with Type 1 glycogen storage disease (GSD) is reported. Since she was 15 years old, several episodes of gouty arthritis had developed. At the age of 18, proteinuria was pointed out. Hepatomegaly, renomegaly out of proportion to the impairment of renal function, hyperuricemia, hyperlipidemia, fasting hypoglycemia and lactic acidemia were observed. The diagnosis of GSD was established on the basis of a glucose tolerance test, glucagon test and liver biopsy. The findings of renal biopsies performed at the ages of 24 and 27 years old suggested that glomerular damage might have preceded the tubulo-interstitial lesion.

Adult↗
PubMed1990

IgA nephritis associated with plasminogen abnormalities.

Two patients with IgA nephritis associated with hereditary plasminogen abnormalities are described. One patient had dysplasminogenemia and the other had plasminogen deficiency. In both patients, renal biopsy specimens showed significant arteriosclerotic changes in addition to mesangial proliferation. Increased fibrinopeptide A concentration in their plasma suggested increased thrombin generation. In one patient, no systemic arteriosclerosis coexisted, judging from normal optic fundi and the absence of neurological and cardiac abnormalities. In IgA nephritis, renal vascular hyalinosis is often observed, probably resulting from vascular injury. Thus, it was suggested that the decreased fibrinolysis and renal vascular injury of these patients synergistically induced more fibrin thrombi and accelerated arteriosclerosis of the kidney. These cases imply the important role of fibrinolytic disorders in the progression of IgA nephritis.

Adult↗
PubMed1989

[Determination of plasma alpha human atrial natriuretic polypeptide using monoclonal antibodies in patients with chronic renal failure].

To clarify the molecular nature and dynamics of circulating alpha human atrial natriuretic polypeptide (alpha hANP) in chronic renal disease, the plasma concentrations of alpha hANP were determined by radioimmunoassays using two distinct monoclonal antibodies (MoAbs). One MoAb (10B1) recognized N-terminus of alpha hANP, while the other (C351) recognized the ring structure. The preliminary studies revealed a close correlation (r = 0.97, p less than 0.0001) between plasma alpha hANP measured with 10B1 and C351 MoAbs, supporting the theory that the main circulating form is alpha hANP(1-28). Therefore, the more sensitive radioimmunoassay using MoAb (C351) was used in the present studies. The plasma alpha hANP was 3.8 +/- 1.7 (mean +/- SD) in healthy subjects, 2.7 +/- 1.4 fmol/ml in patients with chronic glomerulonephritis without renal failure, 16.2 +/- 16.8 fmol/ml in patients with chronic renal failure, and 24.3 +/- 10.5 fmol/ml in patients under maintenance hemodialysis. Thus, the elevation of plasma alpha hANP was related to the stages of renal damage. Although the plasma alpha hANP in 18 patients under maintenance hemodialysis declined significantly (p less than 0.01) after hemodialysis, their levels (17.9 +/- 9.0 fmol/ml) after hemodialysis were still higher than those in healthy subjects. On the other hand, a positive correlation (r = 0.65, p less than 0.05) between alpha hANP and creatinine in blood was found only in the group of chronic renal failure before maintenance hemodialysis. These results suggest that an impaired metabolism of alpha hANP in the kidney might play an important role in the elevation of plasma alpha hANP as well as the stimulation of alpha hANP secretion caused by the expansion of extracellular fluid.

Adult↗
PubMed1985

Effect of captopril on heavy proteinuria in azotemic diabetics.

We investigated whether captopril, an angiotensin-converting-enzyme inhibitor, would reduce proteinuria in patients with advanced diabetic nephropathy. Captopril (37.5 mg given in divided doses three times daily) was administered to 10 azotemic diabetics with heavy proteinuria. Urinary protein decreased promptly within two weeks (from 10.6 +/- 2.2 to 6.1 +/- 1.4 g per day [mean +/- S.E.M.]; P less than 0.01). The decrease in proteinuria did not coincide with a fall in systemic blood pressure or in the blood glucose concentration. Serum creatinine and potassium values did not change in any of the patients except one. We suggest that captopril caused a decrease in intrarenal hypertension, which contributed to the reduction of urinary protein excretion. The therapeutic value of this intervention remains to be established.

Adult↗
PubMed1980

Reevaluation of the reaction of formaldehyde at low concentration with amino acids.

Many studies have been reported on the reaction of formaldehyde (FA) with amino acids or proteins, and FA is assumed to react with the alpha-amino group as well as some of the side chain groups. In most of these investigations a large excess of FA relative to amino acids or proteins was employed. In the present study, however, we carried out the reaction with a smaller excess of FA in order to clarify the reactivity, firstly with the alpha-amino groups, and secondly with specific side chain groups. No evidence for so-called Schiff base (-N = CH2) formation was obtained in the reaction with the alpha-amino groups, but the formation of an acid-labile N-hydroxymethyl compound as a major product was suggested by NMR and IR at greater than pH 9.2. There was no indication, however, of the presence of such a product below pH 9.2, and the amount of N-hydroxymethyl product increased in parallel with the reaction pH. The higher the reaction pH (greater than or equal to 9.2), the greater the consumption of FA, up to 2 mol/mol Ala. In addition, the larger the excess of FA, the smaller the amount of free amino group remaining (at pH 9.7). In the assignment of IR spectra, discrete absorption bands of the alpha-carboxyl group of Ala were observed, which reflected ionization states of the alpha-amino group, and these were utilized for analysis of the reaction mechanism. Furthermore, among amino acids with side chain groups, His, Trp, and Arg showed high reactivity and Asn showed moderate reactivity. The products were relatively stable and were purified and subjected to instrumental analyses. Sixteen other amino acids including Tyr and Lys did not yield stable products. The products from Arg were unique because of the non-involvement of the amino group, and were reversibly converted to the original Arg upon acid hydrolysis. The products from His, Trp and Asn all involved amino or amide nitrogen forming cyclic ring structures with methylene derived from FA. The chemical structures of these products were determined on the basis of elemental analyses, MS and NMR.

Amino Acids↗
PubMed1976

Distribution of Cellular Carbohydrates during Development of the Mycelium and Fruitbodies of Flammulina velutipes.

Flammulina velutipes (Curt. ex Fr.) Sing. was grown on potato-glucose solution freed of most starch. Glucose uptake and dry weight changes in the colony indicated that the large fruitbodies derived their substrates partly from glucose remaining in the medium and partly from cellular constituents stored in the mycelium and small fruitbodies. Changes in the amounts of low molecular weight carbohydrates, glycogen, and four cell wall polysaccharide fractions were followed in the mycelium and fruitbodies. Trehalose, arabitol, and smaller amounts of mannitol were the main stored low molecular weight carbohydrates. A large net loss of these compounds occurred in the mycelium and small fruitbodies after their growth ceased. The carbohydrates accumulated in the large fruitbodies, but were also partly metabolized in the colony. Reducing sugars were minor components, and included about 30 to 50% glucose and a small undetermined quantity of fructose. Glycogen was the main storage carbohydrate in the mycelium, and was also stored in the small fruitbodies. It was broken down in both structures during growth of the large fruitbodies which accumulated only small amounts. During the same period, almost 45% of the maximum amount of cell wall polysaccharides were degraded in the small fruitbodies, but not in the mycelium.By feeding (14)C-glucose in replacement medium, incorporation of radioactivity into carbohydrates was followed in the colony during fruit-body development. Total incorporation was highest in trehalose, next highest in glycogen, and the rest was found in polyols and cell wall polysaccharides except for a few per cent which remained in endogenous glucose. In the large fruitbodies, specific radioactivity in glucose was much lower than in trehalose and mannitol. The labeling patterns in the mycelium and large fruitbodies suggested that trehalose, mannitol, and possibly arabitol were translocated into the stipes and pilei.

Journal Article↗
PubMed1972

An Action Spectrum for Light-induced Primordium Formation in a Basidiomycete, Favolus arcularius (Fr) Ames.

The action spectrum for the initiation of fruiting (primordium formation) in Favolus arcularius was determined on the equal response basis. The detectable effect of light was observed in the region between 350 to 560 nanometers, showing six distinct peaks at 374, 398, 424, 446, 480, and 514 nanometers. The half maximum response is reached with 1.8 x 10(8) ergs per cm(2) at the most effective wavelength, 398 nanometers. Since the inhibitors, diphenylamine and quinacrine, had no consistent effect on the primordium formation, it is suggested that the possible photoreceptor pigment(s) may be neither carotenoid nor flavinoid.Comparing the action spectrum with those for some other fungi, the possibility that the photoreceptor system of this fungus may consist of two pigments is discussed.

Journal Article↗