Search PubMed⌕ Search

Biomedical subjects

F Saito

Publications and source records attributed to F Saito.

At least 55 records · Page 3Linked to original sources

Prognosis and clinical features of intractable epilepsy: a prospective study.

Of the epileptic patients who were treated for > or = 5 years until the end of 1990 and had more than four seizures in 1990, 63 patients had been treated without interruption until the end of 1995. We analyzed their clinical courses from 1990 to 1995 prospectively. More than half the subjects were diagnosed with temporal lobe epilepsy. Twenty cases had presumed etiology, and 32 had neuropsychiatric complications. Of the subjects whose seizures were not controlled with conventional antiepileptic drugs (AED), 11 cases demonstrated significant improvement when new AED; that is, lamotrigine, vigabatrin, clobazam, topiramate, tiagabine or CGP33101 were added. However, 10 patients did not respond to new AED. Presumed etiology, neuropsychiatric complications, multiple epileptic foci in EEG and abnormalities on head CT or MRI were characteristics of the patients whose seizures were resistant to new AED.

Adult↗

The major allergen of Dendropanax trifidus Makino.

Dendropanax trifidus Makino (family Araliaceae, syn. Gilibertia trifida Makino) has been reported as causing allergic contact dermatitis in Japan. To identify the major allergen, fractionated extracts of fresh leaves of Dendropanax trifidus were patch tested on 2 patients with hypersensitivity to the plant. Cis-9,17-octadecadiene-12,14-diyne-1, 16-diol (I), an analog of falcarinol, was identified as an active component. 18 normal control subjects were patch tested with the leaf of Dendropanax trifidus and I diluted to 0.05% in pet. 4 of them showed active sensitization to the leaf of Dendropanax trifidus and I. Our results suggest that I is the major allergen of Dendropanax trifidus and is a strong sensitizer. The results of patch testing on patients and control subjects with the leaves of Fatsia japonica Decne. et Planch. and Hedera helix L., which also belong to the Araliaceae family, and urushiol are also shown.

Adult↗

The role of dystroglycan, a novel receptor of laminin and agrin, in cell differentiation.

Dystroglycan was originally identified as the extracellular and transmembrane constituents of a large oligomeric complex of sarcolemmal proteins associated with dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene. During the last few years, dystroglycan has been demonstrated to be a novel receptor of not only laminin but also agrin, two major proteins of the extracellular matrix having distinct biological effects. The fact that the drastic reduction of dystroglycan in the sarcolemma, caused by the absence of dystrophin, leads to muscle cell death in DMD patients and mdx mice indicates that, as a laminin receptor, dystroglycan contributes to sarcolemmal stabilization during contraction and stretch of striated muscle cells. Dystroglycan is also expressed in the neuromuscular junction and non-muscle tissues such as kidney, brain and peripheral nerve, and, as a receptor of laminin/agrin, has been implicated in such diverse and specific developmental processes as epithelial morphogenesis, synaptogenesis and myelinogenesis. These findings point to the fundamental role of dystroglycan in the cellular differentiation process shared by many different cell types. In this paper, we review the recent publications on the biological functions of dystroglycan and discuss its roles in cell differentiation.

Animals↗

[Angiotensin I-converting enzyme gene polymorphism and renal disease].

ACE inhibitor is known to have a therapeutic efficacy in renal diseases by reducing proteinuria and maintaining renal function. However, the relationship between ACE gene polymorphism and renal disease has not been fully elucidated. In this study, a 287 base pair(bp) I/D polymorphism of the ACE gene was examined with polymerase chain reaction(PCR) in 100 healthy subjects, 34 patients with chronic glomerulonephritis(CGN), 29 with chronic renal failure(CRF) and 25 with diabetes mellitus(DM) with(13) and without(12) nephropathy. We also measured serum ACE activity of these patients. ACE genotype and derived allele frequencies in each disease group did not differ significantly from those in healthy subjects. In all disease groups, values of serum ACE activity were higher in genotype DD than in genotype II. These findings suggest no significant association between I/D polymorphism of the ACE gene and renal disease. Further studies are needed to clarify these findings, considering renal function and type of renal disease.

Adult↗

[Mitral valve plasty and LV patch reconstruction for a left ventricular aneurysm with mitral regurgitation].

Three years after myocardial infarction, a 60-year-old man had congestive heart failure caused by left ventricular aneurysm with mitral regurgitation. He underwent the following concomitant operations: (1) patch reconstruction for a left ventricular aneurysm and (2) mitral plasty for a torn chordate and mitral regurgitation by using valvuloplasty, a shortening chordae and a prosthetic ring. A postoperative examination indicated that his cardiac function had markedly improved.

Heart Aneurysm↗

Antihypertensive mechanism of diuretics based on pressure-natriuresis relationship.

We analyzed the hypotensive mechanisms of a thiazide-type diuretic, mefruside, on the basis of the pressure-natriuresis relationship. We performed a 5-week study in eight patients with essential hypertension who were given a high sodium diet (15 to 18 g NaCl per day) during the 1st and 5th weeks, a severely sodium-restricted diet (1 to 3 g/d) during the 2nd week, and a mildly sodium-restricted diet (5 to 7 g/d) during the 3rd and 4th weeks. Mefruside (25 mg/d) was administered during the 4th and 5th weeks. Urinary sodium excretion rate and mean arterial pressure were measured at the end of each week, and the pressure-natriuresis relationship was drawn by plotting urinary sodium excretion rate on the ordinate and mean arterial pressure on the abscissa before and after mefruside treatment. Before treatment, the pressure-natriuresis relationship was linear, and mean arterial pressure was changed as a consequence of sodium intake alteration (1st week, 117 +/- 9 mm Hg; 2nd week, 105 +/- 7; 3rd week, 109 +/- 9). After treatment, however, the change in mean arterial pressure was very small (4th week, 102 +/- 8 mm Hg; 5th week, 104 +/- 7). Mefruside steepened the slope of the relationship (20.8 +/- 10.5 versus 143 +/- 85 [mmol/d]/mm Hg, P <.005) without significantly shifting the x intercept (104 +/- 6 versus 101 +/- 9 mm Hg, P=NS) of the relationship. The increase in the slope was greater in patients whose slope had been depressed and blood pressure was sodium sensitive before mefruside treatment. The hypotensive effect of mefruside during a high sodium diet correlated positively with both the hypotensive effect of sodium restriction (r=.84, P <.01) and the increase in the slope by mefruside (r=.83, P <.02). Thus, mefruside lowers blood pressure especially in patients with high sodium sensitivity mainly by making blood pressure sodium insensitive through its diuretic action. Strict sodium restriction seems unnecessary when diuretics are administered for blood pressure control.

Aged↗

Effects of tri-, di- and monobutyltin on synaptic parameters of the cholinergic system in the cerebral cortex of mice.

Triorganotin compounds like tributyltin have been reported to be biodegraded to diorganotin, monoorganotin and then inorganic tin in animals after they have been ingested. Effects of tributyltin, dibutyltin and monobutyltin on various cholinergic parameters that are involved in synaptic transmission in the mouse cerebral cortex were investigated in vitro. Tributyltin and dibutyltin, but not monobutyltin, inhibited the activity of choline acetyltransferase, both the high-affinity and low-affinity uptakes of choline into synaptosomes, and the binding of [3H]quinuclidinyl benzilate to muscarinic acetylcholine receptors. Tributyltin and dibutyltin, but not monobutyltin, had a slightly suppressive effect on the K(+)-induced release and synthesis of acetylcholine in slices of the cortex. All three butyltins at concentrations from 10(-6) to 10(-4) M had no effect on the activity of acetylcholinesterase. The extent of the inhibitory effects on the cholinergic parameters, apart from the activity of acetylcholinesterase, was slightly greater in the case of tributyltin than dibutyltin, in particularly at the highest concentration (10(-4) M) tested. Therefore, it is concluded that tributyltin metabolites inhibit various parameters of cholinergic activity with a potency ranking of tributyltin > dibutyltin > monobutyltin.

Acetylcholinesterase↗

N-linked oligosaccharide of beta-amyloid precursor protein (beta APP) of C6 glioma cells: putative regulatory role in beta APP processing.

To determine the N-linked oligosaccharide structure of beta-amyloid precursor protein (beta APP), soluble derivative of beta APP (APPs) was purified from the conditioned medium of beta APP cDNA-transfected C6 glioma cells. Two types of APPs with different molecular weight (larger APPs, L-APPs; smaller APPs, S-APPs) were obtained. The antibody against the N-terminal half of amyloid beta-protein showed no immunoreactivity with S-APPs, suggesting extensive truncation at the carboxyl terminus. From lectin blot analysis, the main structure of the N-linked oligosaccharide shared by L- and S-APPs was deduced to be of bi- or triantennary complex type with a fucosylated trimannosyl core and a bisecting GlcNAc residue. Additionally L-APPs was deduced to have Gal beta 1-->4GlcNAc, Fuc alpha 1-->2Gal beta and Sia alpha 2-->6Gal beta structures on its outer chains. However, lectins which recognize Fuc alpha 1-->2Gal beta and Sia alpha 2-->6Gal beta structures showed no reactivity with S-APPs. The present results suggest that the processing of beta APP may be regulated via the heterogeneity in the fine structure of its sugar chains.

Amyloid beta-Protein Precursor↗

Structure and chromosomal localization of a human water channel (AQP3) gene.

A cDNA encoding rat AQP3, a water channel and a member of the MIP family, that is expressed predominantly in kidney medulla and colon was cloned recently. To determine the structure, tissue distribution, and chromosomal localization of the human AQP3 gene, we screened a human kidney cDNA library with rat AQP3 probe and isolated a cDNA coding for human AQP3 protein. The deduced amino acid sequence of human AQP3 was 91% identical to rat AQP3. Human AQP3 mRNA was expressed in colon, kidney, liver, pancreas, lung, peripheral leukocytes, spleen, and prostate. The human AQP3 gene was mapped to 7q36.2-q36.3 by chromosome fluorescence in situ hybridization.

Amino Acid Sequence↗

Transesophageal echocardiographically detected atherosclerotic aortic debris in a patient with systemic embolism following coronary angiography.

Transesophageal echocardiography (TEE) has enabled detection of the cardiac source of systemic emboli. We report the case of a patient who manifested systemic, multiple embolization in the kidney, skin, and upper gastrointestinal tract following coronary angiography. TEE allowed visualization of the atherosclerotic debris in the thoracic aorta. The clinical picture of the patient was consistent with that of cholesterol embolism. We recommend that patients with extensive atherosclerotic disease should undergo TEE before cardiac catheterization or other invasive procedures involving the aorta are carried out.

Aorta, Thoracic↗

Cytogenetic analysis of 23 Japanese patients with amyotrophic lateral sclerosis.

The cytogenetic analysis of 23 Japanese patients with amyotrophic lateral sclerosis is reported. G-banded chromosomes of cultured peripheral blood lymphocytes of one subject had a constitutional chromosomal translocation, t(7;13)(p22;q21). No constitutional chromosome abnormality was found in any of the other 22 Japanese patients with amyotrophic lateral sclerosis tested.

Adult↗

NFATx, a novel member of the nuclear factor of activated T cells family that is expressed predominantly in the thymus.

The nuclear factor of activated T cells (NFAT) regulates cytokine gene expression in T cells through cis-acting elements located in the promoters of cytokine genes. Here, we report the cDNA cloning, chromosomal localization, and initial characterization of a transcription factor related to NFATp and NFATc. The novel molecule, designated NFATx, exhibits in its middle a region very similar to the Rel homology domain in NFATc and NFATp. The amino-terminal region of NFATx also shows significant similarities to corresponding sequences in NFATc and NFATp and contains three copies of a conspicuous 17-residue motif of unknown function. We provide evidence showing that NFATx can reconstitute binding to the NFAT-binding site from the interleukin 2 promoter when combined with AP1 (c-Fos/c-Jun) polypeptides and that NFATx is capable of activating transcription of the interleukin 2 promoter in COS-7 cells when stimulated with phorbol ester and calcium ionophore. NFATx mRNA is preferentially and remarkably found in the thymus and at lower levels in peripheral blood leukocytes. The expression pattern of NFATx, together with its functional activity, strongly suggests that NFATx plays a role in the regulation of gene expression in T cells and immature thymocytes.

Amino Acid Sequence↗

Human AQP2 and MIP genes, two members of the MIP family, map within chromosome band 12q13 on the basis of two-color FISH.

The human AQP2 (collecting duct water channel, aquaporin 2) gene encodes a 271 amino acid protein and is a member of the MIP (major intrinsic protein of lens fiber) gene family. Using two-color fluorescence in situ hybridization on high-resolution R-banded chromosomes and human genomic DNA clones for AQP2 and MIP as probes, we found that both genes mapped closely within the human chromosome region 12q13.

Animals↗