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T Terashima

Publications and source records attributed to T Terashima.

At least 181 records · Page 10Linked to original sources

Variances in pharmacokinetic parameters due to assay methods for beta-methyldigoxin.

A digoxin radioimmunoassay (RIA) or fluorescence polarization immunoassay (FPIA) kit is frequently used in routine therapeutic drug monitoring (TDM) of beta-methyldigoxin (MD) by applying a calibration curve made using the corresponding digoxin calibrators. The variances in the plasma levels (61 samples) and pharmacokinetics (5 patients) due to these two different assay methods for MD were examined in our patients with congestive heart failure. Although the plasma levels of MD measured by these methods were well correlated (r = 0.956, p less than 0.001) to each other over a wide range, RIA showed significantly lower values (p less than 0.01) in the subtherapeutic range (less than 0.80 ng/ml), but significantly higher values (p less than 0.002) in the therapeutic and toxic ranges (0.80-2.00 and 2.00 less than ng/ml), respectively than FPIA. This trend occurred with increasing concentrations. When MD samples, spiked in normal human plasma, were analyzed by these methods, RIA showed almost true MD values and gave larger values than FPIA with a mean ratio of FPIA to RIA of 0.83. In contrast, normal plasma samples, each spiked with a MD metabolite such as digoxigenin-bisdigitoxide or digoxigenin-monodigitoxide, showed higher values by 10 to 22% in FPIA. These observations are in good agreement with the findings obtained in a pharmacokinetic study that RIA gave significantly higher levels than FPIA, only in the early stage after MD administration, resulting in a smaller total volume of distribution and a larger beta value in the elimination phase, as compared with FPIA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Asymptomatic low molecular weight proteinuria: studies in five patients.

Asymptomatic low molecular weight proteinuria, a disease recently reported by Suzuki et al. [1985], was found in five boys, two pairs of brothers and a sporadic patient aged 3 to 11 years. Their urinary proteins contained 56% to 67% of proteins of less than 40,000 mol wt, defined as low molecular weight proteins by Suzuki et al. [1985], an indication that proximal tubular reabsorption of these proteins is impaired in these patients. Their glomerular function tests and intravenous urography were normal. An attempt was made to identify urinary low molecular weight proteins in these patients, using Western blotting analysis of the protein bands separated by sodium dodecylsulfate polyacrylamide gel electrophoresis. All five proteins tested were detected: alpha 1-acid glycoprotein (mol wt 44,000), alpha 1-microglobulin (mol wt 33,000), retinol-binding protein (mol wt 21,000), lysozyme (mol wt 14,000), and beta 2-microglobulin (mol wt 11,800). The latter two proteins had been identified in the disease by other means by Suzuki et al. [1985], while the other three were newly identified. Light microscopic studies of renal biopsy specimens from these patients revealed in three of four patients tested focal global or segmental glomerular sclerosis with scattered intratubular casts and focal tubular atrophy. Immunofluorescence staining of the renal biopsy specimens for the five proteins revealed some in the lumens of the proximal tubules and in the casts in the distal or collecting tubules, while only retinol-binding protein was found in the epithelial cytoplasm of the proximal tubules.

Child↗

Observations on the cerebellum of normal-reeler mutant mouse chimera.

The normal-reeler chimera mouse (+/+ in equilibrium with rl/rl) provides an experimental system in which an analysis of the migration of immature neurons in the cerebellum can be accomplished. In the present study, five chimera mice were produced from embryos of the wild-type control (C57Bl/6N) and the reeler mutant mouse (BALB/c) by the aggregation technique. The isozyme pattern of glucosephosphate isomerase (GPI) revealed that the brain tissue in the chimera contained both isozymes of the BALB/c (reeler) and C57Bl/6N (normal) strains, implying that internal mosaicism of the cerebellum truly existed. We found no abnormality in the cerebellum of the chimera mouse: the neuronal and glial subpopulations revealed no difference from those of the control. Such normalization of the cerebellum in the chimera suggests that the disturbance of neuronal migration in the reeler is attributable to an abnormal cell-to-cell interaction between migrating young neurons and the radial glial cells.

Animals↗

Successive appearance of glutathione S-transferase-positive cells in developing rat brain: choroid plexus, pia mater, ventricular zone and astrocytes.

Indirect immunocytochemical staining with antisera raised against purified glutathione S-transferase (GST) was employed to analyse astrogliogenesis in rat brain from embryonic day-16 (E16) rats to birth (which occurs at E20) and in postnatal rats to day 56 (P56). Some GST-positive cells are already recognized at E16 in the choroid plexus and pial surface. At a slightly older age--between E18 and birth--GST-positive cells are located in the ventricular zone. After this age, GST-positive cells are easily recognized in the subventricular zone and in astroglial cells of white and gray matter. On the other hand, neurons and oligodendroglial cells have never been stained all through the ages examined.

Animals↗

Correlation between astrogliogenesis and blood-brain barrier formation: immunocytochemical demonstration by using astroglia-specific enzyme glutathione S-transferase.

The formation of the capillary-glial complex of developing rat brain ranging in age from embryonic day 16 (E16) rats to birth, which occurs at E20, and in the postnatal rats to day 56 (P56) was determined by measuring the horseradish peroxidase (HRP) activity, which was exogenously injected and penetrated within the brain. The activity of glutathione S-transferases (GSTs) which are located exclusively in astroglial cells was also determined. HRP penetrated into and resided within the central nervous system until birth, although after this age the tracers were rarely observed to be included. On the other hand, GST activity was first detected at E18, and after P5 it increased remarkably. The functional significance of astroglial cells located at the blood-brain or blood-ventricle interface is considered, and we suggest that the ontogenetic development of a blood-brain barrier is compatible with the corresponding appearance of GST.

Animals↗

Alteration of the primary pattern of central myelin in a chimaeric environment--study of shiverer----wild-type chimaeras.

Using chimaeras produced from the shiverer mutant with a BALB/C background (white coat color) and normal mice of the C57BL/6N strain (black coat color) by the aggregation method, the morphological patterns of the central myelin sheaths were examined by electron microscopy, with special reference to the structure of the myelin lamellae of the one genotype in an environment dominated by the other genotype. The results obtained may be summarized as follows. The oligodendrocytic processes of both genotypes are able to interact independently with the axon unrelated to its genotype. The lamellar structure of the myelin sheath, i.e., whether or not it is composed of alternating major dense and intraperiod lines, is primarily determined by the genotypes of the oligodendrocytes concerned. The processes of shiverer oligodendrocytes can spirally enwrap axons in the chimaeric CNS which shows dominance of the normal genotype. In contrast, in the environment of shiverer dominance, the spiral arrangement of the oligodendrocytic processes of the normal genotype is often disturbed, probably by the oligodendrocytic processes of the shiverer genotype. Thus, the primary pattern of the myelin sheaths can be altered under the chimaeric condition, and the formation of the myelin sheaths depends essentially on the behavior of the oligodendrocytic processes, which is determined by the genetic specificity.

Animals↗

Projections of the group y of the vestibular nuclei and the dentate and fastigial nuclei of the cerebellum to the interstitial nucleus of Cajal.

Experiments were performed to study the projection of the group y of the vestibular nuclei and the dentate and fastigial nuclei of the cerebellum to the interstitial nucleus of Cajal (INC) in cats by using retrograde axonal transport of horseradish peroxidase (HRP) and electrophysiological methods; and to study the vestibular responses of such projection neurons. Following injections of HRP into the unilateral INC, with partial involvement of the surrounding reticular formation, including the nucleus of Darkschewitsch (ND), many retrogradely labeled neurons were found in the dorsal part of the group y nucleus contralateral to the injection site. Labeled cells were also seen in the contralateral dentate nucleus, frequently in its caudal-ventral part, and in the contralateral fastigial nucleus at all rostrocaudal levels, but most frequently in its caudal part. In electrophysiological experiments performed on cats anesthetized with alpha-chloralose or N2O and paralyzed with gallamine, group y, dentate and fastigial nuclei neurons were antidromically activated by weak stimuli that were confined to the contralateral INC. Depth-threshold curves for antidromic activation of such neurons revealed that the lowest threshold points were within the INC, but not in the ND. The INC-projecting neurons in the group y and dentate nuclei did not respond to electrical stimulation of the ipsilateral or contralateral vestibular nerve, indicating that they do not receive direct labyrinthine inputs. On the contrary, many fastigial neurons projecting to the INC responded to labyrinthine stimulation, suggesting that they may be involved in the vestibular reflexes. These results suggest a difference in properties of INC-projecting neurons in these nuclei.

Animals↗

Distribution and morphology of callosal commissural neurons within the motor cortex of normal and reeler mice.

Retrograde transport of horseradish peroxidase was used to examine the cells of origin of the callosal commissural fibers (CC neurons) in the primary motor cortex of normal and reeler mice. Quantitative analysis of the intracortical, laminar distribution, and dendritic orientation of CC neurons was performed in conjunction with qualitative observation of their morphology. For comparison, similar quantitative data were obtained for the cells of origin of the corticospinal tract (CST) of normal and reeler mice from materials described previously by Terashima et al. ('83). In the normal mouse, CC neurons are distributed in a bilaminar pattern such that the largest number of cells are located in supragranular layers II and III and in infragranular layer V. The majority of CC neurons are normal (upright) pyramids, although a few in the upper zone of layer VI are inverted pyramidal cells. In the reeler mutant, CC neurons are found in all cortical layers, but two-thirds are situated in the lower half of the cortex. On the basis of the celL shape and orientation of the apical dendrite, CC neurons of the reeler were classified into six morphological types: (1) typical pyramidal, (2) inverted pyramidal, (3) tumbled, (4) hook-shaped, (5) polymorphic, and (6) simple. The apical dendrites of the CC neurons in all layers of the cortex of the reeler mouse are randomly oriented; no direct relationship between the intracortical position of the soma and orientation of the apical dendrite was found. In contrast, CST neurons in the reeler mutant are concentrated in the outer third of the cortex, and there is a relationship between the laminar distribution of these cells and the alignment of their dendrites with respect to the pial surface: the apical dendrites of CST neurons lie in superficial layers tend to be oriented obliquely, whereas those of CST neurons in the deeper of cortex most often are oriented vertically, i.e, toward the pial surface. Quantitative analysis revealed that the relative intracortical positions of CC and CST neurons are reversed in the reeler mutant although both populations exhibited greater laminar disposition, and as a consequence, there is more intermingling of the two cell groups in the reeler than in the normal mouse. Thus, the present study suggests that the normal cytoarchitectonics of the primary motor cortex are inverted in the reeler mutant mouse.

Animals↗

Observations on Golgi epithelial cells and granule cells in the cerebellum of the reeler mutant mouse.

Cerebella of reeler mutant mice at two months of age were studied by the Golgi impregnation method to elucidate the detailed configurations of the Golgi epithelial cells and granule cells. On the basis of configuration of their Bergmann fibers, the Golgi epithelial cells of the reeler were relatively normal, or assumed inverted, swan neck, stellate, bipolar, small, or fan shapes, although their morphological changes were continuous rather than abrupt. Radially ascending Bergmann fibers, as well as disoriented ones, arose from the soma of these varieties of Golgi epithelial cells. In many areas, the granule cells were normally aggregated under the molecular layer and constituted the granular layer, although several granule cells were regionally arrested in migration within the molecular layer in some small areas. The axon of the granule cells ascended sinuously or obliquely, extended horizontally, looped around, or descended. In some cases, the granule cells had no T-like bifurcation of the axon, and assumed a bipolar form.

Animals↗

Clinicopathological correlation of IgA nephropathy in children.

22 patients with IgA nephropathy aged 7-16 years, 15 of whom were found by mass urine screening of school children, were divided into three groups based on the degree of their proteinuria at admission: group A (n = 6) below 0.5 g/day of urine protein, group B (n = 7) between 0.6 and 3.0, and group C (n = 9) above 3.0 g/day of urine protein. The degree of proteinuria seemed to be related to the severity of pathological changes of the glomerular basement membrane; most severe in group C, moderate in group B, and minimal in group A. IgA deposits in the mesangial area were found in all groups of patients, but those in the capillary walls were most frequently found in group C. In addition to electron-dense deposits in the mesangial area, which was found in all groups of patients, the subendothelial and subepithelial deposits were the most remarkable changes found in group C. During the clinical observation period, which was between 2.0 and 7.1 years, no patient belonging to group A progressed to groups B or C. 4 cases in group C developed chronic renal failure, but none in the other groups did. The amount of urine protein might be used as a valuable parameter of the pathological damage of the glomerulus in children with IgA nephropathy.

Adolescent↗