Biomedical subjects
Publications and source records attributed to T Kanda.
Three cases of patients with cardiac myxoma who had attacks of acute myocardial infarction are presented. Cineangiographic study showed normal coronary arteries. Immunohistochemical and serologic examination revealed that both interleukin-6 and interleukin-8 were secreted in cardiac myxoma. The authors discuss the relation between these cytokines and myocardial infarction with normal coronary arteries.
PURPOSE: The MR findings in patients with spastic diplegia were investigated and the role of MR imaging in assessing the extent of brain injury was evaluated. MATERIAL AND METHODS: 39 male and 24 female patients (preterm/term 43/20) were imaged using a 0.5 T MR system. RESULTS: The MR findings in term patients were quite different from those in preterm patients; 55% of the term patients showed normal and minimal changes on MR, whereas 90.7% of the 43 preterm children had periventricular leucomalacia. The deep cerebral white matter was the most frequently involved site. Objective measurements revealed significant reductions of the entire sagittal area of corpus callosum in diplegic patients in comparison with normal controls. The motor palsy severity correlated well with the extent of corpus callosum involvement. CONCLUSION: The corpus callosum appears to be a sensitive marker site for the assessment of the extent of white matter injury.
To isolate mutations related to the ubiquitin system, I constructed a plasmid carrying the YUH1 and UBP1 genes (genes of ubiquitin-specific processing proteases) whose expressions were under the control of the galactose-inducible GAL1-GAL10 promoter. Cells of a strain carrying the plasmid were mutagenized with ethyl methanesulfonate. One mutant, which showed galactose-dependent growth at a high temperature (37 degrees C), was isolated from about 380,000 mutagenized colonies. The mutation responsible for galactose-dependent growth at 37 degrees C was a single nuclear recessive mutation designated as uby1-1. UBP1 and YUH1 as well as the GAL1-GAL10 promoter are required to suppress uby1-1. At the restrictive temperature, a uby1-1 mutant did not arrest at a specific phase of the cell cycle, but still lost viability. Even at the permissive temperature (30 degrees C), the uby1-1 mutant grew somewhat slowly and showed pleiotropic phenotypes including hypersensitivity to stresses such as cadmium and canavanine, and sporulation defects. The genomic DNA fragments in a single-copy plasmid which complemented uby1-1 were isolated. Chromosomal mapping, sequencing and subcloning analyses indicated that the gene complementing uby1-1 is RSP5, which encodes a ubiquitin-protein ligase (E3) homologous to E6-AP (E6 associated protein). Deletion, complementation and linkage analyses revealed that UBY1 and RSP5 are the same gene. Therefore, the E3 protein encoded by RSP5 (UBY1) is required for vegetative growth, sporulation and stress response. The present procedure using suppression by co-overexpression of two cloned genes will be useful to isolate mutations of related genes and to analyze biochemical pathways and gene-interactions.
PURPOSE: Outer segments of the photoreceptor rods that are phagocytized by the retinal pigment epithelial (RPE) cells contain a high proportion of polyunsaturated fatty acids (PUFA). PUFA are susceptible to lipid peroxidation. We hypothesized that the resulting peroxides could injure RPE cells leading to retinal degeneration. Accordingly, we compared the effects of linoleic acid (LA) and its hydroperoxide (LHP) on the growth and morphology of RPE cells using laser scanning microscopy and transmission microscopy. METHODS: We counted the number of RPE cells after incubation for 24 and 48 hrs with concentrations of LA or LHP of 0.035, 0.175, and 0.35 mM. To observe the actin filaments, cultured RPE cells were stained with rhodamine phalloidin. The cells were prefixed with 2% glutaraldehyde and postfixed in 1% osmium tetroxide. Specimens were embedded in Epon 812 after dehydration, and the ultrathin sections were doubly stained with 2% uranyl acetate and 2% lead acetate for examination by transmission electron microscopy. RESULTS: Exposure to LA or LHP produced dose-dependent damage to RPE cells with a significantly greater effects of LHP than LA. After incubation for 24 hrs with 0.35 mM LA, the number of vacuoles in RPE cells exceeded that observed in control RPE cells by 365 nm laser microscopy. Exposure to 0.35 mM LHP for 24 hrs produced a pycnotic nucleus, with diffuse and granular autofluorescences observed in and around it. Exposure of RPE cells to 0.35 mM LA for 24 hrs showed that the LA incorporated into the lysosomes was digested and released extracellularly from lysosomes via exocytotic vesicles. However, such exposure to LHP damaged the RPE cells, including the membranes in the pinocytotic vesicles. The packed membranes resembled myelin. CONCLUSIONS: While the LA incorporated into the lysosomes was released extracellularly, LHP persisted in the RPE cells, being observed as autofluorescent lipofuscin-like materials. LHP was cytotoxic, and caused damage to the membranes of pinocytotic vesicles and lysosomes.
Alpha-glucosidase inhibitor can suppress postprandial hyperglycemia by delaying the absorption of carbohydrates in the intestine, and may be useful in obese patients with non-insulin-dependent diabetes mellitus (NIDDM) and preserved insulin secretion. We encountered an obese elderly patient with NIDDM in whom gait disturbance had developed after cerebral hemorrhage and who suffered from ileus after treatment with voglibose. The patient had received voglibose which is reported to cause fewer abdominal symptoms than acarbose, for 15 days. The patient, a 63-year-old woman, was given a diagnosis of NIDDM in February 1995, and was treated with a sulfonylurea agent. However, her glycemic control remained poor and she was admitted to our hospital in April 1995. Her body mass index was 30.5 kg/m2 and laboratory investigation revealed a fasting plasma glucose level of 211 mg/dl, a postprandial (2 h) plasma glucose level of 288 mg/dl, HbAlc of 9.9%, a fasting insulin level of 9 microU/ml, urinary C-peptide excretion of 95.7 micrograms/ day, and an coefficient of variation of R-R value of 2.1%. Fifteen days after glibenclamide was replaced by to voglibose, abdominal pain, nausea, constipation, and ausculatory sounds of gurgling developed, and niveau were noted on an abdominal roentgenogram which indicated that simple ileus had developed. Voglibose was discontinued and the patient was treated with an enema and hot air. She recovered from simple ileus on the next day. This patient had had two abdominal surgeries and a cerebral hemorrhage, and her daily physical activities were limited, which might have contributed to ileus. In elderly patients with NIDDM, a history of abdominal surgery and the amount of daily exercise must be considered when deciding whether or not to give alpha-glucosidase inhibitors.
Despite the fact that vertigo has been one of the most frequent complaints encountered in daily practice in an ENT outpatient clinic, it is believed to be the most unwelcome subject for ENT physicians. The reasons are diverse; e.g., the understanding of vertigo is still a difficult task for most physicians and requires time-consuming multiple studies. However, answers to those questions, although speculated a posteriori, are yet to be substantiated. Therefore, we have analyzed the data obtained from multiple questionnaires that were addressed to ENT physicians practicing in Chiba Prefecture in November of 1993. However, those who work in publicly run hospitals were excluded from the study. The study included otorhinolaryngologists who were members of the Society of Otorhinolaryngology of Japan. We received filled questionnaire forms from 76 of 155 members (49%). The age ranged from 33 to 82 years (mean 55.8 years, 68 men and 8 women). From these questionnaires, it became apparent that physicians are not necessarily reluctant to see patients with vertigo. Instead, most ENT physicians appeared to be actively paying attention to this symptom and to be making efforts to approach its diagnosis and treatment. Although we are not certain if the data obtained here represent the majority of ENT physicians, the positive attitudes toward the patients with vertigo/dizziness would certainly encourage those of us who are interested in this particular symptom category.
We investigated the effect of amiloride, a Na(+)-H+ exchange blocker, on ventricular hypertrophy in a murine model of dilated cardiomyopathy (DCM). Mice with DCM were given orally amiloride for 60 days. The ratio of heart weight to body weight and left ventricular cavity dimension were significantly smaller in both amiloride groups than those in furosemide and control (untreated DCM) groups (p < 0.05). The fiber diameter was significantly smaller in amiloride groups than that in furosemide group (p < 0.01). Plasma and cardiac angiotensin II (AII) levels were decreased in amiloride-treated groups compared with those in furosemide or control group (p < 0.05). Our findings suggest that amiloride prevents the development of myocardial hypertrophy and left ventricular dilatation in DCM in association with a reduction of AII.
We inquired whether the type of diabetic glomerulosclerosis, diffuse or nodular, is of value as an alternative to microalbuminuria in predicting later progression of renal disease. To answer this question, we conducted a retrospective cohort study in eleven Japanese non-insulin-dependent diabetes mellitus patients with normo- to microalbuminuria. Nodular diabetic glomerulosclerosis was found in six patients, and diffuse diabetic glomerulosclerosis in five patients. The mean follow-up period was 41.5 months (range 12-65). Three patients developed persistent proteinuria and one developed chronic renal failure. Mean level of serum creatinine in all patients was elevated from 0.97 +/- 0.23 mg/dl (SD) to 1.10 +/- 0.37 mg/dl (P = 0.098). The rate of increase in serum creatinine was 0.068 +/- 0.115 mg/dl/year in nodular diabetic glomerulosclerosis, and 0.023 +/- 0.069 mg/dl/year in a diffuse one. No difference was found between these two types of diabetic glomerulosclerosis (P = 0.445). We conclude that in normo- to microalbuminuria diabetic nephropathy the type of diabetic glomerulosclerosis, diffuse or nodular, is not necessarily an alternative to microalbuminuria in predicting its later progression in Japanese non-insulin-dependent diabetes mellitus patients.
This study was designed to evaluate the effects of amlodipine, a new calcium channel blocker, on the development of right ventricular hypertrophy and thickening of the media of the pulmonary arteries in a rat model of pulmonary hypertension. Pulmonary hypertension was induced in rats by administering a single injection of monocrotaline, 80 mg/kg. The oral administration of amlodipine, 3, 10, or 30 mg/kg/day, was initiated 24 hours later (day 1). On day 28 of therapy, we determined the right ventricular systolic pressure (RVSP), the mass ratio of the right ventricle (RV) to the left ventricle, the thickness of the wall of the RV, the diameter of myocardial fibers in the RV, the percent thickness of the media of the pulmonary artery, and the percent area of smooth muscle in the pulmonary arteries. The magnitude of all parameters was significantly less in the rats administered amlodipine, 30 mg/kg/day, vs. the control group given monocrotaline alone. RVSP, the percent medial thickness, and the percent smooth muscle area, were significantly lower in rats administered a dose of amlodipine, 30 mg/kg/day vs. 10 mg/kg/day. The oral administration of amlodipine, 30 mg/kg/day, inhibited the development of RV hypertrophy and medial thickening of the pulmonary arteries in rats exposed to monocrotaline significantly more effectively vs. the untreated control exposed only to monocrotaline.
The serum level of alpha-fetoprotein (AFP) is a marker for primary liver tumors. To evaluate the relationship between the serum level of AFP and the positivity of liver tissue for this marker, specimens of liver were obtained at autopsy from patients with hepatocellular carcinoma (HCC). Tissues were fixed with formalin or Kryofix and immunostained for AFP. Serum AFP titer at autopsy was positively correlated with AFP staining in tissue fixed by Kryofix and stained with monoclonal antibody against AFP. The correlation was significant for plasma levels of AFP above 5,000 ng/ml. Results suggest that elevated serum AFP levels are an indicator of the progression of HCC.
A lipid-binding protein identical to the rat intestinal bile acid-binding protein, termed I-15P, was expressed in steroid hormone-producing tissues such as ovary and adrenal gland, but not testis. In immature rats, I-15P was expressed in intestine but not in ovaries. The expression of I-15P in the ovaries of immature rats was induced to the level in immature rats by gonadotropin treatment. This suggests that the expression of I-15P in the ovaries is controlled by the ovarian cycle. The present results indicate that the expression of I-15P is developmentally and hormonally controlled in a tissue-specific manner.
We have isolated a cDNA encoding a human intestinal 15-kDa protein (I-15P) from a human ileal lambda gt 11 cDNA library, using a full-length rat I-15P cDNA. One clone encompassed 571 nucleotides and encoded a 128-amino-acid protein with a calculated molecular mass of 14355 Da. The deduced amino acid sequence of human I-15P showed high similarity to the rat counterpart (78%), mouse ileal lipid-binding protein (80%) and porcine gastrotropin (75%). It also exhibited 36% similarity to human liver fatty-acid-binding protein (L-FABP). Northern blot analysis of human I-15P revealed a single transcript only in ileum, however, the reverse-transcription/PCR demonstrated expression in ovary and placenta, but it was much lower than in ileum. Transformation of Escherichia coli with the I-15P cDNA resulted in the efficient expression of a protein that was identical to the ileal cytosolic I-15P. In vitro binding studies revealed that the bacterially expressed recombinant I-15P showed much lower affinities for palmitate and oleate than L-FABP. However, it showed similar affinity for taurocholate, compared with a control, BSA. Comparison of the structural features of human I-15P and human L-FABP suggested that loss of a long alpha-helix region and hydrophobic profile of I-15P may be attributable to a unique ligand-binding specificity of I-15P.
The E6 oncoprotein of human papillomavirus type 16 (HPV 16) [151amino acids (AA) long] contains four metal-binding motifs, C-X-X-C, and is postulated to form two 29-AA finger-like structures in the N-terminal and C-terminal halves, which mediate degradation of p53 and binding to p53, respectively. We constructed a series of E6 mutants with single-AA substitutions in these finger regions (AAs 34-62 and 107-135) and examined their transforming function for human embryonic kidney (HEK) cells in conjunction with HPV 16 E7 and their interaction with human p53 in vitro. The mutants with substitution of L for F-37, G for L-50, S for Y-54, and P for L-110, which did not transform HEK cells, showed markedly lowered activity to direct degradation of p53. The mutants with substitutions of G for R-39, G for V-42, G for Y-43, L for F-47, and G for V-53 lost the transforming function, but they could mediate degradation of p53 at levels comparable to the activities of the wild-type and transforming mutants. Like the wild type, all of the E6 mutants were localized by immunofluorescence to the nuclei of human TS21B cells or monkey COS-1 cells, except for the E6 mutant with substitution of G for Y-43 whose expression was undetectable. The levels of E6 mutants metabolically labeled in COS-1 cells were comparable to those of the transforming E6s. The data indicate that E6-directed degradation of p53 is necessary but not sufficient for HPV 16-mediated transformation of of HEK cells.
We have studied the glycosphingolipid composition in an F-11 neuroblastoma cell line originated from hybridization of a mouse neuroblastoma cell line (N18TG-2) with rat dorsal root ganglion cells. The total lipid-bound glucose of F-11 cells was estimated to be 0.28 micrograms/mg of protein and the total lipid-bound sialic acid was 0.82 micrograms/mg of protein. The major neutral glycosphingolipids were Gb4 (37% of the total neutral glycosphingolipids), Gb3 (15%), LacCer (21%), and GlcCer (15%). The major gangliosides were found to be GM3 (37% of the total gangliosides), GD3 (27%), O-acetylated GD3 (18%), and GD1a (4%), with trace amounts of GD2. The unusually high concentration of O-acetylated GD3 is consistent with its putative role as a tumor marker. Immunocytochemical localization studies of GD3 and O-acetylated GD3, examined by mouse monoclonal antibodies R24 and D1.1, respectively, revealed that the cell bodies and processes were all positively stained. To elucidate the role of O-acetylated GD3 in tumorigenesis, we transfected F-11 cells with the O-acetylesterase gene from influenza C virus. Compared with the original cell line, the transfected cells showed a dramatic increase in the level of GD3 (150% of that in the control cells) and a significant decrease of the concentration of O-acetylated GD3 (27% of control cells). In addition, the transfected F-11 cells exhibited a morphology different from the parental cells with enlarged cell bodies and elongated neurites. We conclude that alteration of ganglioside composition, particularly the expression of GD3 and O-acetylated GD3, may be associated with the morphological changes observed in this cell line.(ABSTRACT TRUNCATED AT 250 WORDS)
Treatment of cultured bovine brain microvascular endothelial cells (BMECs) with interleukin 1 beta (IL-1 beta), an inflammatory cytokine, was shown to induce the accumulation of sulfoglucuronosyl paragloboside (SGPG), a glycolipid bearing the HNK-1 epitope. This resulted in the attachment of a greater number of human lymphocytes to the treated than to the untreated BMEC monolayers. Attachment of human lymphocytes to the IL-1 beta-activated BMEC cells could be blocked either by incubation of the human lymphocytes with an anti-L-selectin antibody or by application of an anti-SGPG antibody to the BMECs. These results suggest that SGPG may act as an important ligand for L-selectin for the regulation of the attachment of activated lymphocytes and their subsequent invasion into the nervous system parenchyma in inflammatory disorders of the central and peripheral nervous systems.
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BACKGROUND: The ovary of adult rats expresses two types of cytoplasmic fatty acid binding proteins (FABP), i.e., heart FABP (H-FABP) and intestinal 15 kDa protein (I-15P). We studied immunohistochemically the cellular localizations of these FABPs in the ovaries of rats at various postnatal ages and in the ovaries of immature (3-week-old) rats treated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG). METHODS: The cryosections of ovaries were incubated with polyclonal antibodies against H-FABP and I-15P, and the immunoreactions were visualized at both light and electron microscopic levels. RESULTS: The immunoreactivity for H-FABP occurred temporarily in the follicular epithelial (granulosa) cells from 3 days to 2 weeks post partum, and then was localized exclusively to the theca/interstitial gland cells from 2 weeks to adulthood. In contrast, the immunoreactivity for I-15P appeared temporarily in a small subset of theca/interstitial gland cells from 2 to 3 weeks, disappeared at 4 weeks, and was localized exclusively to the corpus luteum cells after the onset of ovulation in the animal around 5 weeks. In the immature rat ovaries induced to ovulate by treatment with gonadotropins, I-15P-immunoreactive cells were first recognized in the luteinized granulosa layer of large preovulatory follicles, and increased in number progressively in the developing corpora lutea after the ovulation. CONCLUSIONS: Two types of FABPs are expressed in distinct steroid-producing cell types of rat ovary, and their expressions seem to be regulated in coincidence with the expressions of respective steroid hormones. These results suggest that FABPs play specific roles in the ovarian hormone synthesis.
This study was designed to compare the effects of semotiadil, a novel calcium antagonist, with those of diltiazem on the development of right ventricular hypertrophy and medial thickening of pulmonary arteries in a rat model of pulmonary hypertension. Pulmonary hypertension was induced by a single injection of monocrotaline (80 mg/kg). Twenty-four hours later (day 1), oral administration of semotiadil (10, 30, or 100 mg/kg per day) or diltiazem (100 or 300 mg/kg per day) was initiated. The wall thickness of the right ventricle (RV), the RV myocardial fiber diameter, the percent medial pulmonary artery thickness, and the percent area of smooth muscle in pulmonary arteries were determined on day 28. The magnitude of all parameters was significantly less in the group of seven rats that received semotiadil at 100 mg/kg per day than in the group of seven rats treated with diltiazem at 300 mg/kg per day. Semotiadil at 100 mg/kg per day inhibits the development of RV hypertrophy and medial thickening of pulmonary arteries significantly more effectively than diltiazem at 300 mg/kg per day.