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Biomedical subjects

S Ichikawa

Publications and source records attributed to S Ichikawa.

At least 127 records · Page 7Linked to original sources
PubMed1997

[A family with dentato-rubro-pallido-luysian atrophy (DRPLA): an intergenerational contraction of the CAG repeat].

We describe the relation of the CAG repeat length to the genetic anticipation in a Japanese family with dentato-rubro-pallido-luysian atrophy (DRPLA). The proband, a 21-year-old woman, developed epilepsy at age 19. Her mother has displayed cerebellar ataxia, choreoathetosis, and dementia since age 40, and the grandmother has shown cerebellar ataxia since age 52. So a genetic anticipation was observed. The CAG repeat sizes of peripheral blood lymphocytes from the proband, mother, and grandmother were found to be 61, 59, and 60, respectively. Thus, the mother showed earlier onset but a smaller CAG repeat length as compared to the grandmother. This case is thought to be rare and valuable in respect that the intergenerational contraction of the CAG repeat was shown in spite of the genetic anticipation was observed.

Adult↗
PubMed1997

[Atopic dermatitis and related factors observed at infant physical examination at health centers].

We investigated the incidence of atopic dermatitis and related factors at infant physical examination at health centers. Subjects were 900 infants (290 four-month-old infants, 298 one-year and six month-old infants, 312 three-year-old infants) who participated in infant physical examinations in Kanazawa-ku, Yokohama City. Overall, we analyzed 696 infants whose mothers had cooperated with the survey by completing questionnaires during physical examinations, and who submitted to examination by consulting dermatologists. The incidence of atopic dermatitis was 11.6% in 4-month-old infants, 12.2% in 1.5-year-old infants, and 12.1% in 3-year-old infants. The following were found to be related to the atopic dermatitis of infants. 1. Family history of atopic dermatitis in their mothers and older siblings. 2. Mothers' limited diet during pregnancy (avoiding some food which are suspected allergens). 3. Past history of molluscum contagiosum. 4. The frequency of taking bath. While epidemiological surveys of atopic dermatitis have previously been performed, the criteria at each survey was not identical and results could not be compared precisely. In this survey, 1. Dermatologists specializing in atopic dermatitis performed examinations. 2. All diagnoses were made according to standardized criteria which are applied nationwide. 3. All subjects were from a specific region. Because of this approach, this survey provides important information that can form the basis of comparison for future epidemiological surveys of atopic dermatitis.

Age Factors↗
PubMed1997

[The HIV/AIDS Epidemic in Cambodia].

In December 1995 and March 1996, we visited institutes which were conducting epidemiological studied of HIV/AIDS in Cambodia, and obtained data for further collaborative study between Japan and Cambodia. Data included information on AIDS patients and HIV infected persons, and behavioral epidemiology of CSWs (Commercial Sex Workers). The cumulative reported number of AIDS patients and HIV infected persons in Cambodia was 86 and 2,536 cases respectively in 1995. The cause of infection was mostly heterosexual contact with very few cases from injecting drug use (IDU) and other causes. The seroprevalence rate of HIV antibody among donated blood rapidly increased from 0.08% in 1991 to 4.47% in 1995, and those among CSWs and pregnant women were 37.9% and 2.6%, respectively, in 1995. The average rate of condom use among CSWs was 66%, but the rate of usual usage was only 14%. These results indicate that the HIV/AIDS epidemic had spread rapidly through CSWs, that it had been spread among peoples in communities, and that usage of condoms among CSWs was insufficient in Cambodia. Without strong countermeasures against HIV/AIDS in this country, HIV/AIDS epidemic may spread significantly to not only peoples in this country but also those in neighbouring countries in the future.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Reduced serum T3 level in a patient with nodular goiter and cardiac myxoma.

We report the unusual case of an 87-year-old woman with cardiac myxoma and adenomatous goiter. She exhibited slight elevations of serum interleukin-6 (IL-6), but levels of thyroid hormones such as T3, free T3 and free T4 were all abnormally low. Interleukin-6 may potentiate the alteration of thyroid metabolism.

Aged↗
PubMed1996

Structural characterization of a novel glycoinositolphospholipid from the parasitic nematode, Ascaris suum.

A novel glycosphingolipid containing inositol phosphate as an acidic group has been demonstrated in whole tissues of the porcine roundworm, Ascaris suum. The thin layer chromatographic pattern of the total acidic glycolipid revealed the presence of several components, of which a major component (named AGL) with positive reactions toward both orcinol-sulfuric acid (sugar) and molybdate (phosphate) spray reagents was isolated and purified by the use of successive column chromatography on DEAE-Sephadex and silicic acid (latrobeads). From structural studies including compositional sugar analysis, hydrogen fluoride degradation, methylation analysis, periodate oxidation, proton magnetic resonance spectroscopy and fast atom bombardment mass spectrometry, the structure of AGL was deduced to be Gal alpha 1-2Ins(1-->)-P-Cer. Aliphatic constituents were lignoceric acid and its 2-hydroxy homologue as the principal fatty acids, and octadecasphinganine and branched heptadecasphinganine as the major sphingoids.

Animals↗
PubMed1996

Tertiary structure of destrin and structural similarity between two actin-regulating protein families.

Destrin is an isoprotein of cofilin that regulates actin cytoskeleton in various eukaryotes. We determined the tertiary structure of destrin by triple-resonance multidimensional nuclear magnetic resonance. In spite of there being no significant amino acid sequence homology, we found that the folding of destrin was strikingly similar to that of repeated segments in the gelsolin family, which resulted in a new protein fold group. Sequential dissimilarity of the actin-binding helix of destrin to that of gelsolin explains the Ca2+-independent actin-binding of destrin. Possible mechanisms of phosphorylation-sensitive phosphoinositide-competitive actin binding, of pH-dependent filament severing, and of nuclear translocation with actin in response to stresses, are discussed on the basis of the tertiary structure.

Actin Depolymerizing Factors↗
PubMed1996

Complete removal of sphingolipids from the plasma membrane disrupts cell to substratum adhesion of mouse melanoma cells.

GM-95, a mutant cell line derived from mouse melanoma MEB-4 cells, is deficient in glycosphingolipids (GSLs) due to the lack of ceramide glucosyltransferase-1 activity (Ichikawa, S., Nakajo, N., Sakiyama, H., and Hirabayashi, Y. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 2703-2707). In this study, we examined the involvement of the complex sphingolipids in cell to substratum adhesion. Immunofluorescent and chemical analyses revealed that the complex sphingolipids were significantly concentrated in the detergent-insoluble substrate attachment matrix of both GM-95 and MEB-4 cells. In spite of the absence of GSLs, GM-95 cells retained the ability to adhere to extracellular matrix (ECM) proteins such as fibronectin, collagen, and laminin. When both GM-95 and MEB-4 cells were treated with neutral sphingomyelinase, GM-95 cells were rounded up and detached from all ECM proteins examined. In contrast, neither the morphology nor the adherence of MEB-4 cells was altered. Under this treatment, sphingomyelin (SM) became undetectable in both cells. A similar inhibition was observed upon pretreatment of cells with fumonisin B1 or ISP-1, both of which block the synthesis of ceramide, a common precursor of both GSLs and SM. Stable transfectants expressing GSLs, which were established by transfection of glucosyltransferase-1 cDNA into GM-95 cells, became resistant to neutral sphingomyelinase-mediated rounding up and detachment from ECM proteins. In conclusion, the complex sphingolipids play critical roles in cell to substratum adhesion, and the presence of either GSLs or SM is sufficient for the adhesion.

Animals↗
PubMed1996

Expression cloning of a cDNA for human ceramide glucosyltransferase that catalyzes the first glycosylation step of glycosphingolipid synthesis.

We have isolated a cDNA encoding human ceramide glucosyltransferase (glucosylceramide synthase, UDP-glucose:N-acylsphingosine D-glucosyltransferase, EC 2.4.1.80) by expression cloning using as a recipient GM-95 cells lacking the enzyme. The enzyme catalyzes the first glycosylation step of glycosphingolipid synthesis and the product, glucosylceramide, serves as the core of more than 300 glycosphingolipids. The cDNA has a G+C-rich 5' untranslated region of 290 nucleotides and the open reading frame encodes 394 amino acids (44.9 kDa). A hydrophobic segment was found near the N terminus that is the potential signal-anchor sequence. In addition, considerable hydrophobicity was detected in the regions close to the C terminus, which may interact with the membrane. A catalytically active enzyme was produced from Escherichia coli transfected with the cDNA. Northern blot analysis revealed a single transcript of 3.5 kb, and the mRNA was widely expressed in organs. The amino acid sequence of ceramide glucosyltransferase shows no significant homology to ceramide galactosyltransferase, which indicates different evolutionary origins of these enzymes.

Amino Acid Sequence↗
PubMed1996

Yearly variation of spontaneous somatic mutation frequency in the stamen hairs of Tradescantia clone KU 9 grown outdoors, which showed a significant increase after the Chernobyl accident.

Scoring of spontaneous somatic pink mutation frequency in the stamen hairs of Tradescantia clone KU 9, a heterozygote for flower color (blue/pink; the blue color being dominant), was carried out for 11 years on plants grown outdoors, during the period of May 11-31 (for 3 weeks) in every year from 1982 to 1992. Weekly and yearly variations of the spontaneous mutation frequency were observed, and such variations could mostly be correlated to the difference in temperature. That is, the mutation frequency was generally higher in the weeks and years when the temperature was relatively low, showing the strongest negative correlation with the average minimum temperature. The variations were also correlated to the diurnal temperature difference, the mutation frequency being higher with larger diurnal temperature difference in general. However, the mutation frequency observed in 1986 was exceptionally higher than that expected from the temperature for this year, and was very significantly higher than for other years. The scoring of mutation frequency was thus continued in 1986 for an additional 4 weeks (June 1-28), and it was confirmed that such higher mutation frequencies lasted for 6 weeks in total. The exceptionally high mutation frequency seemed to be related to the radioactive fallout which occurred in early to mid May of 1986, even in Japan, after the serious nuclear reactor accident at Chernobyl, and also to the biological concentrations of radioactive nuclides which subsequently occurred, although it was difficult to conclude this definitely. The mutation frequency in 1987 was second highest, and was also significantly higher than the lowest mutation frequency observed in 1990.

Climate↗
PubMed1996

Changes in diastolic regional stiffness of the left ventricle before and after coronary artery bypass grafting.

To evaluate the effect of coronary artery bypass grafting (CABG) on regional diastolic function of the left ventricular wall, we applied the concept of the stiffness constant to the diastolic sigma-ln (1/H) relation, where sigma is the mean wall stress, and H is the wall thickness of the region of concern, and ln (1/H) is the natural logarithm of the reciprocal of wall thickness. We assessed 12 cardiac regions in six patients with coronary artery disease who underwent CABG at the Cardiovascular Hospital of Central Japan between May 1994 and January 1995. Left ventricular pressure and regional wall thickness were measured simultaneously, with a micromanometer-tipped catheter and by two-dimensional echocardiography, respectively, before and after CABG. The stiffness constant (K) was obtained by fitting the diastolic sigma-ln (1/H) data points to an exponential curve with zero asymptote: sigma = Cexp[Kln (1/H)]. Preoperatively, the stiffness constant in the affected region (CABG region) was greater than that in the unaffected region (non-CABG region) (4.79 +/- 2.56 vs 2.95 +/- 0.72). Postoperatively, the stiffness constant in the CABG region was significantly decreased, to 3.21 +/- 1.22. The stiffness constant, which is derived from the sigma-ln (1/H) relation, is useful for the assessment of LV regional diastolic function.

Aged↗
PubMed1996

The prognosis and the treatment of patients with a C3/4 spinal cord injury.

Twenty patients with a C3/4 spinal cord injury have been treated in our hospital since 1974. There were 15 new patients. The average follow up period was 68 months, ranging from 7 to 162 months. The 15 new cases were classified as Frankel A in nine cases, B in one, and C in five. Frankel A or B were usually accompanied by either an unstable spinal fracture or by spinal canal stenosis at the C3/4 level. Twelve patients received surgery. At the most recent follow up, eight of the 15 patients (53.3%) had improved according to Frankel's classification. Five, all Frankel A on remission, have died between 2 and 156 months after injury. Seven patients required tracheotomy on account of severe respiratory disturbance.

Adult↗
PubMed1996

Association between family history and gastric carcinoma among young adults.

The relationship between family history of gastric carcinoma and gastric carcinoma in Japanese under 40 years of age was analyzed. The subjects were 108 gastric carcinoma patients (86% were diffuse type) at 9 hospitals in the Kanto area of Japan. Firstly, incidence of gastric carcinoma among the parents of the subjects were compared with that in the general population. Observed/expected (O/E) ratios (P-value) were 1.8 (0.06) for all subjects, 1.3 (0.62) for male subjects, 2.1 (0.04) for female subjects, 0.5 (0.41) for early carcinoma, 2.6 (P<0.01) for advanced carcinoma, 2.3 (0.22) for intestinal-type carcinoma and 1.7 (0.13) for diffuse-type carcinoma. Association between gastric carcinoma and parents' history of gastric carcinoma was strong among women and regarding advanced carcinoma, and the difference in O/E ratios between early and advanced carcinoma was remarkable. Secondly, factors related to advanced-stage gastric carcinoma were analyzed. Histological type (diffuse and intestinal types) was not related, but family history of gastric carcinoma among parents and grandparents was related to advanced stage, and the relationship was independent of other factors. The odds ratio (95% confidence interval) was 3.3 (1.1-9.9). Family history may be related to stage of gastric carcinoma through its relationship to the manner or speed of the tumor's progression. We hypothesis that some genetic factor exists which is involved both in progression from early to advanced stage and in occurrence of gastric carcinoma.

Adolescent↗
PubMed1996

Polyacrylamide gel electrophoretic serum protein patterns of acute inflammation induced by intramuscular injection of turpentine in young broiler chickens.

Changes in the serum protein patterns accompanying inflammation in young broilers were examined by polyacrylamide gradient gel electrophoresis. Sera were obtained from blood of 4-week-old male broilers after induction of acute inflammation by an injection of 0.5 ml/kg turpentine. Electrophoretic patterns at 48 hr after injection, showed an increase in transferrin (Tf) and a segment containing albumin (Alb) with multiple peaks. The unbound iron binding capacity (UIBC) increased by 10 times, and the serum iron (SI) concentration in acute inflammation was reduced to one-half its initial value. These are considered to be typical changes in serum proteins and iron after acute inflammation.

Animals↗
PubMed1996

Changes in adhesion molecule expression during distinct patterns of immune cell migration in the inflamed lung.

In response to antigen inhalation, immune cells including alveolar macrophages expressing a VIP1 receptor subtype (VIP1R), lymphocytes and leukocytes participate in the inflammatory event, migrating into and from vascular regions in lung tissue of sensitized mice. To analyze these migratory mechanisms of immune cells, we immunohistochemically examined the expression of the following: cellular adhesion molecules, lymphocyte function-associated antigen-1 (LFA-1) very late activation antigen-4 (VLA-4), and the alpha V (alpha v) subunit and their respective ligands, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and fibronectine; the examination was carried out in pulmonary tissue from days 0, 2, 6 and 12 following intratracheal administration of sheep red blood cells (SRBC) as an antigen to previously sensitized mice. Two days following the antigen challenge, VIP1R-positive macrophages strongly expressing the alpha v integrin subunit were found clustered on the endothelial surface and among the aggregates of perivascularly infiltrated leukocytes. On the endothelium of arteries, veins and capillaries, alpha v immunoreactivity was prominently reduced, whereas staining for fibronectin was enhanced more than the prechallenge control level. The blood vessel endothelium was also stained positive for VCAM-1 and ICAM-1, while many of the infiltrating lymphocytes were positive for VLA-4 and LFA-1 immunolabelings. By post-challenge, day 6, delta v integrin subunit immunoreactivity was re-expressed on the blood vessel endothelium and only weakly expressed on VIP1R-positive macrophages, which were in retreat from the leukocyte-aggregating perivascular region and located in the alveoli. VLA-4 bearing lymphocytes conspicuously increased in number among the perivascular leukocytes, while immunoreactivity for LFA-1, VCAM-1, ICAM-1 and fibronectin was unchanged from that for post-challenge day 2. The results indicate that the expression of the alpha v-bearing integrin and its ligand fibronectin drastically changes as pulmonary inflammatory responses. These changes in expression of adhesion molecules during immune response may play an important role in the dynamic regulation of VIP1R-positive macrophage migration in the lung parenchymal compartment.

Animals↗
PubMed1996

Immune cell migration through the arterial wall in the murine lung during a pulmonary inflammatory response.

Perivascular accumulation of leukocytes in the lung was induced by intratracheal administration of sheep erythrocyte antigen to primed mice. The route of migration of intravascular leukocytes to the perivascular space in the lung, in particular from arteries, and the structure of lymphatic vessels among the aggregated leukocytes were examined by transmission electron microscopy. Leukocytes--lymphocytes, granulocytes, monocytes and macrophages--were demonstrated to adhere to the endothelial surface and to migrate between endothelial cells to reach the internal elastic lamina of arteries. Becoming conspicuously constricted, the leukocytes penetrate through this elastic lamina. They further migrate through the smooth muscle layer to the interstitium, passing through the external elastic laminar region. At 2 days after antigen administration, dilated lymphatic vessels containing large numbers of leukocytes in the lumen and bearing endothelial gaps open to the interstitium began to be seen. The lymphatic walls were more convoluted and richer in pinocytotic vesicles than those prior to antigen challenge. This study confirms the light microscopic findings by Curtis et al. (1990) that arteries, besides veins, venules and capillaries, may represent a major route of inflammatory cell entry into the lung parenchyme in an acute and vigorous immune response. In addition, lymphatic vessels were suggested to be newly formed for the transport of fluid and immune cells from the sites of inflammation in the lung.

Animals↗
PubMed1996

[Single-stage surgery for annulo aortic ectasia, Stanford type-A aortic dissection and pectus excavatum in a patient with Marfan's syndrome].

A 43-year-old female was hospitalized on October 25, 1993, due to severe back pain. She was diagnosed with annulo aortic ectasis, Stanford type-A acute aortic dissection and pectus excavatum caused by Marfan's syndrome. On November 30, 1993, single-stage surgery was performed, including modified Bentall procedure, aortic arch replacement, elephant trunk method and sternoplasty. Concerning the procedure for pectus excavatum, sternoplasty was selected because we thought that sternoplasty could endure the long procedure which would cause infection compared with sternal turnover. Postoperative course was satisfactory, and she is well 18 months after surgery.

Adult↗
PubMed1996

[Coronary artery bypass grafting for ischemic heart disease associated with acromegaly: a case report].

Coronary artery bypass grafting (CABG) for ischemic heart disease associated with acromegaly has never been reported in Japan, though coronary artery sclerosis is known as complicating factor in acromegaly. A 44-year-old man with ischemic heart disease was admitted to our hospital and emergency percutaneous transluminal coronary recanalization was performed. After admission, he was diagnosed as acromegaly from endocrinological studies and operated on CABG. The peri- and post-operative course was uneventful in spite of our fear for complications due to acromegalic heart muscle disease.

Acromegaly↗