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Biomedical subjects

O Saitoh

Publications and source records attributed to O Saitoh.

At least 55 records · Page 3Linked to original sources
PubMed1996

Expression of neurofilament proteins in proliferating C2C12 mouse skeletal muscle cells.

Expression of neurofilament proteins, NF140K, NF68K, and NF200K, in C2C12 mouse skeletal muscle cells was studied. Immunofluorescence and immunoblot analyses revealed that NF140K was expressed in proliferating C2C12 cells and its localization was similar to desmin, a muscle-specific intermediate filament protein. NF140K became undetectable in C2C12 cells as muscle cell differentiation proceeded. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analyses confirmed the expression of NF140K, NF68K, and NF200K in proliferating C2C12 cells. Sequences of the RT-PCR products of NF140K and NF68K were identical to that of authentic mouse NF140K and NF68K, respectively. The NF140K and NF68K mRNA were down-regulated during myogenesis in contrast to the up-regulation of mRNA encoding troponin-T. Furthermore, subcloned C2C12 cells, which express NF140K at a higher level, exhibited retarded myogenesis, i.e., delayed onset of myosin heavy chain synthesis and myoblast fusion. These results suggest that neurofilament proteins may play an inhibitory role in commitment of muscle cell differentiation. The presence of neurofilament proteins in skeletal muscle cells indicates that desmin, vimentin, and neurofilament proteins can be expressed in a single muscle cell.

Animals↗
PubMed1996

Differential assembly of cytoskeletal and sarcomeric actins in developing skeletal muscle cells in vitro.

Monoclonal antibodies (McAb) to actin were prepared to analyze the assembly of actin isoforms in developing muscle cells in vitro. One of the antibodies (SkA-06) was specific for alpha-sarcomeric actin isoforms in skeletal and cardiac muscles, while the others recognized cytoskeletal (beta, gamma) actin isoforms in smooth muscle and non-muscle tissues as well as the sarcomeric (alpha) actins. Using SkA-06 and a polyclonal antibody (PcAb) specific for cytoskeletal actins, the subcellular localization of the actin isoforms was examined by immunocytochemical methods. While in developing young myotubes, cytoskeletal and sarcomeric actins were co-localized in nascent myofibrils or stress-fiber-like structures, sarcomeric actins predominated in striated myofibrils in more developed myotubes. When FITC-labeled cytoskeletal and sarcomeric actins were introduced into young myotubes by a microinjection method, the latter became detectable in striated structures sooner than the former but they were finally incorporated into striated myofibrils. These results suggest that alpha-actin(s) as well as beta- and gamma-actins can be incorporated into myofibrils, but alpha-actin(s) is assembled preferentially into myofibrils in developing muscle cells.

Actins↗
PubMed1996

Fecal lactoferrin as a marker for disease activity in inflammatory bowel disease: comparison with other neutrophil-derived proteins.

OBJECTIVES: 1) To investigate which neutrophil-derived proteins in feces most accurately reflect disease activity in inflammatory bowel disease. 2) To examine the extracellular release of these proteins by activated neutrophils and their stability in feces by in vitro study. METHODS: We studied 41 patients (91 samples) with ulcerative colitis (UC), 34 patients (105 samples) with Crohn's disease (CD), and 25 control subjects. Fecal levels of lactoferrin (Lf), polymorphonuclear neutrophil elastase (PMN-E), myeloperoxidase (MPO), and lysozyme (Lys) were measured by ELISA. We also measured fecal hemoglobin (Hb) and alpha 1-antitrypsin (alpha 1-AT), useful markers of disease activity in UC and CD, respectively. For the in vitro study, blood samples were stimulated with phorbol myristate acetate or latex beads. For the assessment of stability, homogenized stool samples were stored at 4 degrees C, 25 degrees C, and 37 degrees C for various periods. RESULTS: 1) Fecal Lf, PMN-E, MPO, and Lys concentrations were significantly increased in the active phase of the disease compared to the inactive phase in both UC and CD. 2) Fecal Lf, PMN-E, MPO, and Lys concentrations correlated significantly with fecal Hb concentration in UC, whereas fecal Lf, PMN-E, and MPO concentrations correlated significantly with alpha 1-AT concentration in CD. In UC, fecal Lf, PMN-E, MPO, and Lys concentrations were high in 15, 9, 14, and 14 samples, respectively, of 25 samples with normal Hb concentration. In CD, fecal Lf, PMN-E, and MPO concentrations were high in 19, 10, and 16 samples, respectively, of 30 samples with normal alpha 1-AT concentration. 3) The extracellular release of Lf was the most efficient and this molecule was the most stable in feces. CONCLUSIONS: Both our clinical and our in vitro studies suggested that Lf is the most suitable of these proteins to use as neutrophil-derived fecal marker of inflammation for clinical application.

Adult↗
PubMed1995

Reduced size of corpus callosum in autism.

OBJECTIVE: To determine via magnetic resonance imaging if the posterior corpus callosum is reduced in the midline cross-sectional area in autistic patients, consistent with previous reports of parietal lobe abnormalities. DESIGN: Case-control study. SETTING: Tertiary care facility. PATIENTS AND OTHER PARTICIPANTS: Fifty-one autistic patients (45 males and six females; age range, 3 to 42 years), including both mentally retarded and nonretarded patients who met several diagnostic criteria for autism were prospectively selected. Fifty-one age-and sex-matched volunteer normal control subjects were also included. INTERVENTION: None. MAIN OUTCOME MEASURES: Computer-aided measurement of cross-sectional area, areas of five subregions, and thickness profile. RESULTS: Overall size reduction, concentrated in posterior subregions. CONCLUSIONS: Evidence is found of a reduced size of the corpus callosum in autistic patients. This reduction is localized to posterior regions, where parietal lobe fibers are known to project. This finding further supports the idea that parietal lobe involvement may be a consistent feature in autism.

Adolescent↗
PubMed1995

Clinical symptoms and regional cerebral blood flow in schizophrenia.

This study examined the relationship between clinical symptoms and regional cerebral blood flow (rCBF) in schizophrenic patients using single photon emission computed tomography (SPECT). The subjects were 26 medicated schizophrenic patients diagnosed according to DSM-III-R criteria. Clinical symptoms were assessed using the Scale for the Assessment of Negative Symptoms (SANS), selected items for the Positive and Negative Syndrome Scale (PANSS), and the scale for Schneider's first rank symptoms. Resting rCBF was measured using N-isopropyl-p-[I-123] iodoamphetamine (I-123 IMP) SPECT, and relative rCBF distribution was evaluated in nine regions of interest in each hemisphere. Factor analysis of symptom ratings indicated four separate syndromes: psychomotor poverty, alienation (hallucination and disturbance of the self), delusion, and disorganization. Stepwise multiple regression analysis showed the psychomotor poverty syndrome to be correlated with decreased rCBF in bilateral superior frontal areas and increased rCBF in the left thalamus and right basal ganglia. The disorganization syndrome was correlated with increased rCBF in bilateral anterior cingulates and decreased rCBF in bilateral middle frontal areas. The alienation syndrome was shown related to increased rCBF in the right inferior frontal area and parietal area. Dysfunction in distinctive neural networks involving various prefrontal areas would thus appear to underlie these syndromes in schizophrenia.

Adult↗
PubMed1995

Asymmetry of the ventricle and age at the onset of schizophrenia.

The relationship between lateral ventricular size or its asymmetry and age at the onset of schizophrenia was investigated in 20 schizophrenic patients diagnosed according to DSM-III-R criteria. The ventricle-brain ratio (VBR) was determined using three transaxial slices of magnetic resonance image (MRI) and asymmetry of the lateral ventricle was evaluated from the laterality index of the lateral ventricular area: (left-right/left+right) x 100. Each age at the onset of the prodromal and active phase according to DSM-III-R criteria was determined for each patient. The results showed that asymmetry of the ventricle, but not VBR, was significantly correlated inversely with age at the onset of both the prodromal phase and active phase. Neither asymmetry nor VBR correlated with the duration of illness, age at MRI scanning, or severity of clinical symptoms. It would thus appear that greater asymmetry of the ventricle is associated with earlier onset of schizophrenia.

Adolescent↗
PubMed1995

Intestinal protein loss and bleeding assessed by fecal hemoglobin, transferrin, albumin, and alpha-1-antitrypsin levels in patients with colorectal diseases.

Four fecal proteins (hemoglobin, transferrin, albumin, and alpha 1-antitrypsin) were measured by enzyme-linked immunosorbent assay (ELISA) in patients with colorectal diseases. Levels of all 4 proteins were significantly increased in patients with colonic cancer and ulcerative colitis (UC) compared to levels in control subjects, while fecal alpha 1-antitrypsin was particularly elevated in colonic Crohn's disease (CD). That is, the fecal protein pattern of CD was distinct from those of colonic polyps, colonic cancer, and UC. To investigate whether levels of these fecal proteins reflect disease activity in UC and CD, comparative evaluation of fecal proteins in the active and inactive phases was performed. In UC, differences in the fecal concentrations of all 4 proteins were significant between the active and inactive phases of the disease. In CD, however, the difference in alpha 1-antitrypsin concentration was significant. Our results suggest that measurements of these 4 fecal proteins would be useful in the screening of colorectal diseases. In addition, these markers can also be used as indicators of disease activity in inflammatory bowel diseases.

Adult↗
PubMed1995

Cross-sectional area of the posterior hippocampus in autistic patients with cerebellar and corpus callosum abnormalities.

Using MRI methods previously shown to optimize visualization of cytoarchitectonic details in the body of the hippocampal formation caudal to the pes hippocampi, we imaged and quantified the hippocampus proper including the subiculum and the dentate gyrus in 33 autistic patients between the ages of 6 and 42 years and in 23 age-matched normal healthy volunteers. Measures of these structures in autistic patients and normal healthy volunteers differed nonsignificantly, by less than 1.4%, regardless of whether or not the autistic patients were retarded or had a history of seizure episodes. By contrast, measures of vermian lobules VI and VII and the posterior portion of the corpus callosum in these same autistic and normal volunteers differed significantly, by more than 9.9%. The lack of a significant difference in the cross-sectional size of the posterior hippocampal formation between autistic and normal 6- to 42-year-olds is discrepant with predictions based on some, but not all, autopsy studies. This suggests that there is a need for additional quantitative autopsy study of the hippocampal formation and quantitative MRI study of rostral hippocampal regions that we did not explore in the present report. Also, quantitative autopsy and MRI studies have yet to examine hippocampal development in autistic patients younger than 6 years of age; whether early stages of growth are normal or not is unknown.

Adolescent↗
PubMed1995

The forms and the levels of fecal PMN-elastase in patients with colorectal diseases.

OBJECTIVES: To compare the form of polymorphonuclear leukocyte (PMN)-elastase in feces with that in plasma and to investigate the usefulness of measuring fecal PMN-elastase levels in patients with colorectal diseases. METHODS: We examined PMN-elastase complexed with alpha 1-antitrypsin (alpha 1-AT), chymotrypsin, and alpha 2-macroglobulin by ELISA in feces and plasma. Fecal levels of total PMN-elastase were determined in patients with colonic polyp (N = 19), colonic cancer (N = 20), ulcerative colitis (UC; N = 36), colonic Crohn's disease (CD; N = 26), and in control subjects (N = 20). RESULTS: Most PMN-elastase was not complexed with alpha 1-AT, chymotrypsin, or alpha 2-macroglobulin in feces, whereas most plasma PMN-elastase was complexed with alpha 1-AT. Fecal concentrations and daily fecal excretion of PMN-elastase were significantly increased in patients with active UC (medians 54.8 micrograms/g, 15.14 mg/day) and active CD (41.5 micrograms/g, 10.24 mg/day) compared to those values in control subjects (0.6 micrograms/g, 0.11 mg/day) and in patients with colonic cancer (2.5 micrograms/g, 0.33 mg/day). In inactive UC and CD, these values (3.4 micrograms/g, 0.52 mg/day and 5.2 micrograms/g, 0.59 mg/day, respectively) were significantly lower than in active UC and CD, respectively. In UC, all patients whose rectal biopsies showed infiltration of PMN had high fecal PMN-elastase levels. CONCLUSIONS: Our results suggest that the measurement of fecal PMN-elastase concentrations are useful for monitoring the disease activity of UC and CD, especially when evaluating whether intestinal inflammation has disappeared completely.

Adult↗
PubMed1994

Regulation of A2a adenosine receptor mRNA expression by agonists and forskolin in PC12 cells.

Modulation of A2a adenosine receptor (A2aAR) expression by adenosine agonists was studied in cultured PC12 cell lines. Exposure of A2aAR agonists such as 5'-N-ethylcarboxamidoadenosine (NECA) or CGS-21680 caused a transient increase followed by a decrease of A2aAR mRNA in PC12 cells in 10 h. This was followed by a gradual recovery to control levels by approximately 24 h. These changes were blocked by an adenosine receptor antagonist, xanthine amine congener. Forskolin also induced similar changes in the level of A2aAR mRNA. In addition, A2aAR numbers of PC12 cell membranes were significantly decreased during the NECA-exposure. These results suggest that A2aAR gene expression in PC12 cells is regulated by activation of A2aAR via a mechanism involving the second messenger, cAMP.

Adenosine↗
PubMed1994

Effects of 16, 16-dimethyl prostaglandin E2 on lysosomal membrane stability in rat stomach.

The lysosomal membrane encloses numerous hydrolytic enzymes and prevents the cytoplasm from being damaged by these enzymes. It is possible that the fragility of this membrane may be implicated in the pathogenesis of gastric mucosal damage. We investigated the effects of 16,16-dimethyl prostaglandin E2 (dmPGE2), which is known to protect the gastric mucosa from various noxious agents, on lysosomal membrane stability in the rat stomach. Sodium taurocholate (TC) was used as the damaging agent. To assess lysosomal membrane stability in the gastric mucosa, we assayed acid phosphatase released from lysosomes isolated from a gastric mucosal homogenate. To assess lysosomal membrane stability in gastric surface epithelial cells, we used laser scanning confocal microscopy to observe the fading of red fluorescence in living cells vitally stained with acridine orange. Exogenous dmPGE2 enhanced lysosomal membrane stability in the gastric mucosa, whereas TC decreased it. In gastric surface epithelial cells, exogenous dmPGE2 protected the cells against TC-induced damage and prevented TC-induced decreased lysosomal membrane stability. It was concluded that a decrease in lysosomal membrane stability seemed to be closely involved in the pathogenesis of gastric mucosal damage. Moreover, it appears that stabilization of the lysosomal membrane by exogenous dmPGE2 may contribute to its protective effect in the gastric mucosa, both at the level of gastric surface epithelial cells and in regard to the entire gastric mucosa.

Acid Phosphatase↗
PubMed1994

Immunochemical detection of human lactoferrin in feces as a new marker for inflammatory gastrointestinal disorders and colon cancer.

We have developed a new immunochemical test for fecal lactoferrin (LF) utilizing an enzyme-linked immunosorbent assay (ELISA). The ELISA had a sensitivity of about 10 micrograms/L of lactoferrin and the measurable range was 10.0-1000.0 micrograms/L (1.0-100.0 micrograms LF/g feces). The stability of lactoferrin in feces was greater than that of myeloperoxidase and leucocyte elastase. The fecal concentration of lactoferrin (mean +/- SD) in 35 normal subjects was 0.75 +/- 0.83 microgram/g feces, whereas that in 24 patients with colon cancer was 74.4 +/- 88.3 micrograms/g feces. The fecal lactoferrin concentration of 38 patient with active ulcerative colitis was 307.4 +/- 233.9 micrograms/g feces, and that in 36 patients with active Crohn's disease was 191.7 +/- 231.1 micrograms/g feces. The ELISA for human fecal lactoferrin might be useful in the diagnosis of colon disease.

Adolescent↗
PubMed1994

Impairment in shifting attention in autistic and cerebellar patients.

MRI and autopsy evidence of early maldevelopment of cerebellar vermis and hemispheres in autism raise the question of how cerebellar maldevelopment contributes to the cognitive and social deficits characteristic of autism. Compared with normal controls, autistic patients and patients with acquired cerebellar lesions were similarly impaired in a task requiring rapid and accurate shifts of attention between auditory and visual stimuli. Neurophysiologic and behavioral evidence rules out motor dysfunction as the cause of this deficit. These findings are consistent with the proposal that in autism cerebellar maldevelopment may contribute to an inability to execute rapid attention shifts, which in turn undermines social and cognitive development, and also with the proposal that the human cerebellum is involved in the coordination of rapid attention shifts in a fashion analogous to its role in the coordination of movement.

Adolescent↗
PubMed1994

The brain in infantile autism: posterior fossa structures are abnormal.

Infantile autism is a neurologic disorder of social, cognitive, and language development. Earlier MRI studies found hypoplasia of posterior vermal lobules VI and VII and cerebellar hemispheres in the majority of autistic patients, and recent autopsy analyses find severe Purkinje neuron loss in the posterior vermis (lobules VI and VII and VIII to X) and hemispheres. A second type of cerebellar pathology in infantile autism was recently found: hyperplasia (excessive enlargement) of posterior vermal lobules VI and VII. If the autistic samples in some MRI studies that did not detect cerebellar hypoplasia were actually composed of both the hypoplasia and hyperplasia subtypes, then the autistic mean size reported in such studies would have appeared to be near the normal mean size only because it would be the sum of the two opposite subtypes. To test this possibility, we statistically reanalyzed previously published vermal area measures of 78 autistic patients from four separate studies. The results revealed that the autistic patient samples from these four studies were indeed composed of both the hypoplasia subtype (87%, 92%, 89%, and 84% of patients) and the hyperplasia subtype (13%, 8%, 11%, and 16% of patients). Cerebellar abnormalities have been found in 15 autopsy and quantitative MRI reports from nine laboratories involving a total of 226 autistic cases. Autism may be one of the first developmental neuropsychiatric disorders for which substantial concordance exists among several independent microscopic and macroscopic studies as to the location and type of neuroanatomic maldevelopment. Onset might be as early as the second trimester. Discovery of the etiologies underlying cerebellar maldevelopment may be the key to uncovering some of the causes of infantile autism.

Adolescent↗
PubMed1994

Abnormality of cerebellar vermian lobules VI and VII in patients with infantile autism: identification of hypoplastic and hyperplastic subgroups with MR imaging.

OBJECTIVE: Infantile autism is a neurobehavioral disorder that is widely believed to have etiologically distinct subtypes, including subtypes with a genetic basis, but no neuroanatomic evidence firmly supports this belief. To date, only one type of cerebellar abnormality has been identified in patients with autism: hypoplasia of the vermis and hemispheres. By using a large sample of autistic patients and healthy volunteers along with precise MR imaging and quantitative procedures, we sought to replicate previous reports of cerebellar vermian hypoplasia in autism and to identify additional subtypes of cerebellar abnormality. MATERIALS AND METHODS: Using MR technology, we imaged and measured posterior and anterior vermian regions in 50 autistic patients (2-40 years old) and 53 healthy control subjects (3-37 years old). The autistic patients had social, language, cognitive, behavioral, and medical history characteristics that were typical of the general autistic population. By using precise procedures for positioning and aligning MR slices, we obtained comparable MR images within and across subject groups. RESULTS: Statistical analyses showed two subgroups of autistic patients, one (86% of the patients) with findings consistent with vermian hypoplasia and another (12% of the patients) with evidence of vermian hyperplasia. The hypoplasia subgroup included 43 patients whose mean midsagittal area for vermian lobules VI and VII was 237 +/- 38 mm2, and the hyperplasia subgroup included six patients whose mean area was 377 +/- 12 mm2. Thus, the area of lobules VI and VII in the hypoplasia subgroup was 16% smaller than the mean area in the control subjects (282 +/- 42 mm2) (p < .0001), whereas that in the hyperplasia subgroup was 34% larger (p < .0001). Analyses showed that these two subtypes of vermian abnormalities were present across all ages of autistic patients studied. CONCLUSION: Two different subtypes of autistic patients can be identified on the basis of the presence of vermian hypoplasia or hyperplasia as seen on MR images. Possible origins for vermian hypoplasia include environmental trauma and genetic factors.

Adolescent↗
PubMed1993

Expression of myogenic factors in denervated chicken breast muscle: isolation of the chicken Myf5 gene.

In this study, we have isolated and characterized the chicken Myf5 gene, and cDNA clones encoding chicken MyoD1 and myogenin. The chicken Myf5 and MRF4 genes are tandemly located on a single genomic DNA fragment, and the chicken Myf5 gene is organized into at least three exons. Using genomic and cDNA probes, we further analyzed the mRNA levels of four myogenic factors during chicken breast muscle development. This analysis revealed that myogenin expression is restricted to in ovo stages in breast muscle, and is not detectable in neonatal and adult stages. On the other hand, Myf5 expression is detectable until day 7 post-hatching, and is not found in adult muscle, whereas high levels of MyoD1 and MRF4 are detectable at all stages. To further understand the roles of innervation on muscle maturation, we analyzed the expression of the four myogenic factors in denervated adult breast muscle. We found that MyoD1, myogenin, and MRF4 are induced at high levels in denervated muscle, whereas no change occurs in the level of Myf5. These studies suggest that innervation controls the relative abundance and type of myogenic factors that are expressed in adult muscle, and that when nerve control is removed, the muscle reverts to a neonatal phenotype, with the enhanced expression of three myogenic factors (MyoD1, myogenin, and MRF4).

Amino Acid Sequence↗