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Biomedical subjects

R Tanabe

Publications and source records attributed to R Tanabe.

At least 19 recordsLinked to original sources
PubMed2001

Analysis of prognostic predictors in idiopathic membranous nephropathy.

We studied clinical and histologic parameters at the time of renal biopsy of 19 patients with idiopathic membranous nephropathy (IMN) to investigate the predictors for prognosis of IMN. Nineteen patients diagnosed by open renal biopsy between 1988 and 1993 and followed for at least 5 years were divided into two groups according to the latest follow-up renal function. Group I included 16 patients with normal renal function at the last follow-up point. Group II included three patients with end-stage renal failure at the last follow-up point. Antibodies to CD68, CD45RO, alpha-SMA, collagen IV, and collagen VI were used to investigate glomerular and interstitial changes in biopsy specimens by the indirect enzyme-labeled antibody method. Degree of global glomerulosclerosis, segmental glomerulosclerosis, adhesion to Bowman's capsule, and crescent formation were evaluated by light microscopy (periodic acid-Schiff, periodic acid-metheramine [PAM] staining). The difference between the two groups was analyzed by Mann-Whitney U: test. The number of interstitial cells, the number of interstitial CD45RO-positive cells, and increases of interstitial collagen IV and VI were found to be the most important factors for prognosis of IMN. These findings suggest that the extent of tubulointerstitial changes (cellular infiltration and fibrosis) determines the prognosis of renal function in IMN.

Adolescent↗
PubMed2000

Molecular characteristics and site specific distribution of the pigment of the silky fowl.

Silky fowl, a breed of chicken, is hyperpigmented in its various internal tissues. The pigment was extracted from various tissues of two strains of Silky fowl to determine its molecular structure and internal distribution. Analysis by infrared spectroscopy showed two spectrum patterns of the pigment in Silky fowl; one is from ovary and testis, the other is from periosteum and feather. The difference between the two spectra is possibly due to the sulfur contents of melanin. Especially, the spectra of the pigments from feather and periosteum shared the characteristics of synthesized melanin spectrum in common, which indicates that the melanocytes dispersed in these tissues were functionally the same. According to our quantitative analysis, the tissues examined were classified significantly in the order of the pigment content (p<0.05): periosteum > gonads (ovary or testis) = trachea > or = heart, liver, gizzard, cecum, muscles (Pectoralis and Supracoracoideus) and skin. In addition, the specific regions of embryonic neural crest derived cells, such as cardiac artery and various parts of cephalic tissues, were found to be locally hyperpigmented. These data suggest that hyperpigmentation (fibromelanosis) in Silky fowl chicken occurs in a tissue- and organ-specific manner, which is strongly related to neural crest cell development. It is hypothesized that neural crest cells of the bird, containing melanocyte progenitors, acquire unusual ability to differentiate into melanocytes excessively, and to extend the distribution of their descendant along the destinations of neural crest derivatives.

Animals↗
PubMed1998

Topological isomers of human uroguanylin: interconversion between biologically active and inactive isomers.

The solution structures of the two compounds of human uroguanylin (I and II), which were generated during disulfide bond forming reaction, were found to be topological isomers by 1H-nuclear magnetic resonance spectroscopy. These isomers are interconvertible in aqueous media at rates which vary with the pH and temperature of the solution. Because compound I is active in the cGMP producing assay, but compound II is not, this interconversion may be useful for evaluating the activity of human uroguanylin both in vivo and in vitro.

Amino Acid Sequence↗
PubMed1997

The mechanism of excretion of trientine from the rat kidney: trientine is not recognized by the H+/organic cation transporter.

Trientine dihydrochloride is used to treat Wilson's disease by chelating copper and increasing its urinary excretion. The mechanism of renal excretion of trientine has been investigated in-vivo and in-vitro. Trientine clearance in the rat-was significantly faster than creatinine clearance. When trientine and the same number of moles of copper ions were administered simultaneously to the rat, however, trientine clearance decreased to almost the same level as the creatinine clearance. To clarify this active excretion system for trientine, the uptake of trientine and a physiological polyamine compound, spermine, was investigated using rat renal brush-border membrane vesicles. Although, because trientine and spermine are organic cations, the H+/organic cation transporter is expected to recognize these compounds, neither an outwardly directed H+ gradient nor an inward Na+ gradient stimulated trientine uptake. [14C]Spermine uptake was, nevertheless, trans-stimulated by both unlabelled spermine and trientine and the trans-stimulating effect of spermine on trientine uptake was, furthermore, completely abolished by addition of copper ions to the incubation medium. These results suggest that there is a specific transport system for spermine and trientine on the renal brushborder membrane. This transport system contributes to the secretion of trientine in the kidney proximal tubule but does not recognize the trientine-copper complex.

Animals↗
PubMed1997

A diabetic case with hemoglobin J-Meerut and low HbA1C levels.

A diabetic patient with hemoglobin (Hb) J-Meerut and low HbA1C levels is reported. An automatic glycohemoglobin analyzer used for the determination of HbA1C revealed an abnormal peak of the peripheral blood obtained from a Japanese female with diabetes. She showed a lower HbA1C level (3.7%) than expected from her fasting plasma glucose (172 mg/dl). High performance liquid chromatography and isoelectric focusing indicated that her abnormal hemoglobin was Hb J-Meerut [alpha 120(H3)Ala-->Glu] and it accounted for 28.3% of the total hemoglobin. Abnormal hemoglobinemia should be considered when a major discrepancy between the levels of HbA1C and fasting plasma glucose is observed.

Blood Glucose↗
PubMed1996

Uptake mechanism of trientine by rat intestinal brush-border membrane vesicles.

The uptake characteristics of trientine by rat intestinal brush-border membrane vesicles were studied. The uptake characteristics of trientine were similar to those of the physiological polyamines with respect to the excessive accumulation in vesicles, the pH dependency, the temperature dependency and the ineffectiveness of K+ diffusion potential (inside negative). The initial uptake of trientine was saturable with a K(m) value of 1.13 mM, which was larger than that of spermine and spermidine. Furthermore, the uptake rate of trientine was dose-dependently inhibited by spermine and spermidine. Spermine competitively inhibited the uptake of trientine with a Ki value of 18.6 microM, and it was close to the K(m) value for spermine (30.4 microM). These data suggested that the uptake of trientine was similar to that of spermine and spermidine in rat small intestinal brush-border membrane vesicles, and these polyamines seem to inhibit the absorption of trientine from the gastrointestinal tract.

Animals↗
PubMed1996

[Disposition behavior and absorption mechanism of trientine, an orphan drug for Wilson's disease].

The disposition behavior of trientine, a selective copper-chelating drug for Wilson's disease, and its metabolites in normal patients with Wilson's disease and rats were studied. A high concentration of metabolites appeared in blood samples of patients and rats in the early stage after administration of trientine. Furthermore, large amount of trientine metabolites were excreted into the urine of patients. These results suggest that trientine is remarkably subjected to a first-pass effect. The drug concentration area under the curve (AUC) of the unchanged form and the metabolites of trientine in patients was not dependent on the administered dosage. It seems that the absorption process is an important factor for the disposition behavior of trientine, we have also investigated the uptake characteristics of trientine by rat intestinal brush-border membrane vesicles. The uptake characteristics of trientine were similar to the physiological polyamines, spermine and spermidine. The uptake rate of trientine was dose-dependently inhibited by spermine and spermidine. Moreover, spermine competitively inhibited the uptake of trientine with a Ki value of 18.6 muM. This value is very close to the Km value for spermine (30.4 muM). These data suggested that the uptake mechanism of trientine in rat small intestinal brush-border membrane vesicles was almost identical to that of spermine and spermidine, and that the physiological polyamines seem to have the ability to inhibit the absorption of trientine from the gastrointestinal tract.

Animals↗
PubMed1995

Wegener's granulomatosis with relapsed bleeding of gastric ulcers: a case report.

We treated a 55-year-old male patient with Wegener's granulomatosis (WG) associated with frequent gastric bleeding from multiple ulcerative lesions. Only a few cases of frequent hemorrhaging of peptic ulcers associated with WG have been reported. In our case, a gastric biopsy showed mononuclear cell infiltration in the submucosal area, without granulomas or vasculitis. An endoscopic maneuver, as well as administration of immunosuppressive agents, combined with an H2 receptor antagonist and proton pump inhibitor successfully eliminated the gastrointestinal bleeding. In this case, proof that the gastrointestinal involvement was pathologically related to WG could not be demonstrated because neither granulomas nor vasculitis were observed in the insufficient biopsy specimen of the stomach. It is also possible that the uremic state and cytotoxic agents worsened the gastrointestinal involvement. However, immunosuppressive therapy combined with routine antiulcer treatment was very effective in repairing the ulcerative lesions. The gastrointestinal involvement was considered a possible complication of the WG.

Gastroscopy↗
PubMed1994

Purification and characterization of the 1,200-kDa subfragment of connectin filaments produced by 0.1 mM calcium ions.

When myofibrils prepared from chicken leg muscle were treated with a solution containing 0.1 mM CaCl2 and 30 micrograms/ml of leupeptin, alpha-connectin, which exists as a longitudinal thin filament in a sarcomere, was split into beta-connectin and a 1,200-kDa subfragment. The native subfragment was successfully purified without using any denaturant: It was extracted with 1 M KI solution from the Ca-treated myofibrils and purified by TSKgel G6000PW column chromatography. About 10 mg of the subfragment was yielded from 100 g of starting muscle. Using immunofluorescence microscopy and immunoelectron microscopy, we show here that polyclonal antibodies against the 1,200-kDa subfragment bind to the Z-disk and the epitope, which is about 0.34 micron apart from the Z-disk at a sarcomere length of 2.6 microns; the 1,200-kDa subfragment constitutes the proximal region of connectin filaments. Purified alpha-actinin decorated alpha-connectin and the 1,200-kDa subfragment on nitrocellulose blots of myofibrillar proteins separated by SDS-PAGE. Therefore, we conclude that connectin filaments are anchored to the Z-disk by the binding of the 1,200-kDa subfragment to alpha-actinin.

Actinin↗
PubMed1994

[Numerical and functional alterations in T and B lymphocyte subpopulations in CAPD patients treated with recombinant human erythropoietin].

Recombinant human erythropoietin (r-HuEPO) is recognized to be effective in the treatment of anemia in patients on chronic dialysis. However, studies on the influence of r-HuEPO on the immune system are currently limited and inconsistent. In order to clarify the alteration of T and B lymphocyte subpopulations in patients on CAPD following administration of r-HuEPO, the changes in the expression of HLA-DR, IL2R and CD4/CD8 ratio in the peripheral blood of CAPD patients were evaluated using flow cytometry. In addition, the production of immunoglobulins in peripheral lymphocytes by enzyme immunoassays in 30 CAPD outpatients with anemia, who were treated with r-HuEPO in Tokai University Hospital, was also studied. The dose of r-HuEPO was 6,000 IU in 13 patients in group I and 9,000 IU in 17 patients in group II. The r-HuEPO was given subcutaneously once a week for up to 9 weeks. The level of hematocrit increase significantly following treatment with r-HuEPO. The numbers of lymphocytes and their CD4/CD8 ratios in peripheral blood showed no significant changes after administration of r-HuEPO. The count of HLA-DR-positive T lymphocytes increased significantly and the count of IL2R-positive T lymphocytes decreased and normalized after administration of r-HuEPO. In comparison with healthy controls, basal formation of IgG, IgA and IgM was decreased significantly in PBMC from patients on CAPD. Following treatment with r-HuEPO, the production of IgG, IgA and IgM in PBMC from CAPD patients did not show any significant changes. In conclusion, this study suggested that the administration of r-HuEPO altered T lymphocyte function and also corrected anemia in CAPD patients.

Adult↗
PubMed1992

Ultrasonography and Doppler studies in twin-to-twin transfusion syndrome.

In 40 twin pregnancies, the evaluation of hemodynamics by ultrasound was performed during the period January 1986 through September 1991. The blood flow velocities' waveforms in the umbilical artery, umbilical vein and tricuspid valve, and the total cardiac dimension, were obtained by ultrasonography in conjunction with 3.5 MHz pulsed Doppler ultrasound. Six patients with twin pregnancies were identified as having twin-to-twin transfusion syndrome (TTS), on the basis of like-sex twins with monochorionic diamniotic placentation, vascular anastomosis in the placenta, and umbilical cord venous blood hemoglobin difference exceeding 5 g/dl at delivery. No distinctive findings for TTS were revealed by the measurement of umbilical artery blood flow velocity waveforms. However, cardiomegaly in 5 recipient fetuses and tricuspid regurgitation and biphasic umbilical vein waveforms in 3 recipient fetuses constituted characteristic features of TTS. Ultrasonography and a Doppler study might be beneficial in diagnosing TTS and evaluating the hemodynamics in a recipient fetus.

Blood Flow Velocity↗
PubMed1992

Doppler ultrasonographic assessment of fetal renal artery blood flow velocity waveforms in intrauterine growth retarded fetuses.

Thirty-two blood flow velocity waveforms of the fetal renal artery, umbilical artery and fetal middle cerebral artery were recorded by a pulsed Doppler ultrasound from 28 to 38 gestational weeks in 32 intrauterine growth-retarded (IUGR) fetuses without structural defects. The nonstress test (NST) was performed on the day of pulsed Doppler ultrasonographic examination to assess fetal well-being. Of the 32 fetuses, the pulsatility index (PI: peak systolic velocity minus end diastolic velocity over mean velocity) values in the fetal renal artery were in the normal range in 26 measurements (81.3%), high in 2 (6.3%) and low in 4 (12.5%). The resistance index (RI: peak systolic velocity minus end diastolic velocity over peak systolic velocity) values in the umbilical artery and fetal middle cerebral artery were determined simultaneously in all the patients examined. Of the 12 fetuses with high RI values in the umbilical artery and low RI values in the fetal middle cerebral artery, the PI values in the fetal renal artery were within the normal range in 11 measurements (91.7%) and high in 1 (8.3%). Of the 9 fetuses with loss of fetal heart rate baseline variability in NST, the PI values in the fetal renal artery were within the normal range in 7 measurements (77.8%), high in 1 (11.1%) and low in 1 (11.1%). These data suggest that fetal renal blood flow may not change under the condition of chronic hypoxic state, although the NST shows fetal distress and the pulsed Doppler ultrasound reveals a brain sparing effect in the fetal middle cerebral artery. It is hypothesized that the fetal renal blood flow is controlled by an autoregulation mechanism for oxygen delivery presumably located in the renal artery.

Blood Flow Velocity↗
PubMed1988

Immunohistochemical investigation of topographic localization of phenobarbital and methamphetamine in the rat retina.

The topographic localization of methamphetamine and phenobarbital in the rat retina was studied. It is interesting that the secondary and primary ganglionic cells were stained predominantly only in the case of methamphetamine while in phenobarbital these were not stained. The staining patterns of the inner plexiform layer (strong reaction in phenobarbital and weak reaction in methamphetamine), outer nuclear layer (weak reaction in phenobarbital and strong reaction in methamphetamine) and choroid (very strong reaction in phenobarbital and no reaction in methamphetamine) also showed some differences.

Animals↗
PubMed1988

An improved method for the histological preparation of single hairs and dust samples--morphological and immunological examination.

An improved method of the serological and morphological investigation of human hair is reported. The hair was firmly fixed onto a microscopic slide with cellophane tape and observed microscopically to confirm the cuticula images and the presence of the medulla. A piece of the hair containing the medulla was dissected, embedded in paraffin, and a cross section of this hair was prepared. By treating the sample with immunohistochemistry (biotin-antibiotin ABC technique), the blood type of the hair was confirmed definitively. Dust containing shaved beard can be examined in the same way.

Adhesives↗
PubMed1987

Histochemical demonstration of phenobarbital by immunocytochemistry.

A method for the demonstration of the topographical distribution of phenobarbital at the cellular level in various tissues was established. Mice that had been exposed to various doses of phenobarbital by intraperitoneal injection were killed, and their tissues were fixed with 0.1 M phosphate buffer solution (pH 7.4) containing paraformaldehyde and glutaraldehyde. Thereafter, paraffin and frozen sections were made and stained by the indirect immunoperoxidase method using antisera obtained from commercial sources and used for the immunochemical assay of the blood level of phenobarbital in clinical medicine. A specific positive reaction was observed solely in testing the intoxicated tissues, and this reaction was inhibited when phenobarbital was added to the antisera. The minimal sensitivity of the positive reaction, which can be discerned by observing the stained slides macroscopically, was in the range of 10 mg/kg. Thus, the diagnosis of phenobarbital intoxication in the forensic autopsy can be made by immunohistochemistry. A positive reaction was found in various tissue cells, including nerve cells, myelin sheaths, glia cells, hepatocytes, cells of the alveolar and bronchial wall, epithelial cells of the distal part of the renal tubules, and so forth. Endothelial cells of the capillaries in all tissues gave a strong positive reaction. The immunocytochemical electron microscopy of the hepatocytes revealed that the positive reaction in the cytoplasm was located solely in the intraluminal space of the smooth endoplasmic reticulum. These results indicate some interesting aspects of the pharmacokinetics of phenobarbital in vivo. It is expected that the antisera, which are used widely for the assay of the blood concentration of various drugs (phenobarbital, amphetamines, morphine, and so forth), may be regarded as excellent reagents for immunocytochemistry. This clearly indicates that morphological evidence in toxicology, which had so far remained obscure, can be easily obtained by applying these antisera against various drugs.

Animals↗