[Role of membrane molecules in complement system].
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Animals↗
Biomedical subjects
N Okada
Publications and source records attributed to N Okada.
[Skeletal alterations associated with long-term etretinate therapy].
Radiographic skeletal examinations were performed in sixteen adult patients who had received etretinate therapy for various keratinizing disorders (psoriasis vulgaris 13, pustular psoriasis 2, pustulosis palmoplantaris 1) over periods ranging from 0.7 to 4.5 years. The total dose of etretinate ranged from 5.1 to 36.5 g. In these patients, the frequency and the degree of skeletal alterations including hyperostosis, calcification of ligaments and periosteal thickening was found to be higher than that in age- and -sex matched, nontreated controls. Furthermore, almost all of these patients were asymptomatic and revealed no abnormalities in laboratory data, including levels of serum calcium, inorganic phosphate and alkaline phosphatase. It is necessary for patients who are undergoing long-term etretinate therapy to be examined regularly for such skeletal abnormalities.
Adult↗
[Pachydermoperiostosis--report of a case and review of 121 Japanese cases].
A case of 23 years old man with idiopathic pachydermoperiostosis is reported. He showed cutis verticis gyrata, clubbed fingers and periosteal new bone formation without any causative basic disorder. His serum level of FSH, LH, estradiol and estriol were elevated, but their significance was not clear. Histological examination of the skin from the forehead revealed sebaceous hyperplasia and dermal thickening, where deposit of alcian blue and colloidal iron positive substance were detected. The deformed forehead and eyelids were corrected by plastic surgery. One hundred and twenty one cases of pachydermoperiostosis reported so far in Japan are briefly reviewed. Most of them were male (94.1%), about one fourth had a family history. The principal features are: clubbing of the digits (88.4%), periosteal new bone formation (94.1%), coarsening of the facial features with furrowing of the skin of the face (72.7%) and cutis verticalis gyrata (59.5%). Arthralgia (40.5%), hyperhidrosis of the feet and hands (44.6%), gastric hypertrophy (8 cases), gastric ulcers (5 cases) and endocrine abnormalities (17 cases) were also reported.
Adult↗
[Effect of recombinant human erythropoietin on renal function in predialysis patients].
To assess the effect of recombinant human erythropoietin (EPO) on renal function, the slopes of the regression lines of the reciprocal of serum Cr versus month (l/Cr) were studied in 8 pre-dialysis outpatients (2.9 ml/min. less than Ccr less than 17.0, 21.4% less than Ht less than 27.9) who had been followed for a period of 19 to 94 months. EPO was initially given 3000-6000 U (133 +/- 31 U/Kg/week) once weekly by the intravenous route and was later switched to the dose to achieve a Ht level of 30-35%. Mean Ht increased from 23.6 +/- 0.9 to 33.2 +/- 1.1%, and quality of life and exercise capacity were significantly improved in all patients. The mean slopes of l/Cr after EPO (-0.0050 +/- 0.0020) were not significantly different from the values before EPO (-0.0064 +/- 0.0010). The slopes of l/Cr were significantly decreased by EPO therapy in three patients observed for more than 17 months, however in one patient, it increased significantly during EPO treatment. There were no significant differences in the other 4 patients. The renal function at the initiation of EPO in a patient with increase slope of l/Cr had been the worst, and Ht was mildly increased from 21.4% to 24.1% and the blood pressure did not change significantly. The good effect on renal function observed in 3 patients may, in part, be due to better control of blood pressure and physical condition (including cardiac and immunological function) by the more close follow-up of the patients and the improvement of anemia during the period of EPO therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Inherited complete deficiency of 20-kilodalton homologous restriction factor (CD59) as a cause of paroxysmal nocturnal hemoglobinuria.
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Acetylcholinesterase↗
HRF20, a membrane inhibitor of complement attack, does not protect cells from the cytotoxic reaction by lymphokine activated killer cells.
HRF20, a 20 kDa homologous restriction factor, is a membrane glycoprotein anchored via galactosyl phosphatidyl inositol. Its function is to protect cells from attack by homologous complement. Adsorption of purified HRF20 to Raji cells which have little, if any, of this factor increased their resistance to cytolysis by homologous complement. However, the same cells treated with HRF20 remained sensitive to cytotoxic attack by IL-2 activated lymphocytes (lymphokine activated killer cells; LAK cells). Since LAK cells are effector cells which release perforin, HRF20 does not appear to protect cells from the damage caused by perforin.
Antibodies, Monoclonal↗
A highly repetitive and transcribable sequence in the tortoise genome is probably a retroposon.
On in vitro transcription of total genomic DNA of the tortoise (Geoclemys reevessi), a discrete-sized RNA of 6.5S was obtained that represented a highly repetitive and transcribable sequence in the tortoise genome. Three sequences of the 6.5S RNA gene were sequenced, and a consensus sequence was deduced from these three sequences and one reported previously [Endoh, H & Okada, N. (1986) Proc. Natl Acad. Sci. USA 83, 251-255]. The 5' part of the gene showed close similaries to lysine (rabbit) and threonine (mouse) tRNAs (overall similarity 68-70%), so this tortoise sequence may have evolved from one of these tRNAs. The consensus sequence retained the expected CCA triplet at the 3' end of tRNA, but not at the 3' end of tDNA, supporting the idea that the tRNA-related region of the gene was generated via an RNA intermediate. The 5' and 3' flanking sequences of the four genes were found to be completely different from each other. Fingerprint analysis and S1 nuclease mapping analysis also showed that sequence boundaries of tortoise repetitive units exactly corresponded to RNA species. These results, together with data obtained by Southern blot hybridization, indicated that the 6.5S RNA genes are dispersed in the tortoise genome. Therefore, generation of the tRNA-related region of the gene and amplification of the whole unit of the gene are both RNA-mediated events. The existence of this tortoise sequence suggests that short interspersed sequences are more common in eukaryotic genomes than had previously been thought.
Animals↗
Purification of 1F5 antigen that prevents complement attack on homologous cell membranes.
A mAb, 1F5, has the ability to cause hemolysis by human serum of human E treated with neuraminidase via the alternative C pathway. By Western blotting, this mAb reacts with a glycoprotein having a molecular mass of 20 kDa (1F5Ag). 1F5Ag was isolated from human E by affinity chromatography with mAb-coupled Sepharose. Purified 1F5Ag was then adsorbed to guinea pig E rendering them resistant to human C attack by both the classical and the alternative pathways. Furthermore, experiments with isolated C components revealed that 1F5Ag interferes with both homologous human C8 and C9 in the terminal stage of the C reaction, whereas it has little effect on hemolysis by rabbit C8 and C9. Therefore, 1F5Ag can be called HRF20, which stands for homologous restriction factor of 20 kDa.
Amino Acid Sequence↗
Organization and disorganization of actin filaments in human epidermal keratinocytes: heat-shock treatment and recovery process.
We investigated alterations of actin organization due to heat shock and recovery from the collapse in human epidermal keratinocytes. Exposure of keratinocytes to elevated temperature caused the rapid disintegration of actin filaments. With a heat-shock treatment at 45 degrees C for 10 min, actin filaments disappeared and granular actin was distributed diffusely in the cytoplasm. After return to 37 degrees C, recovery of actin organization was observed. Completely disintegrated granular actin assembled to form actin dots, which tended to group. The grouping actin dots often took a circular, semicircular or arched form. Filamentous actin then extended out from the actin dots. Fine short bundles of actin filaments had a rippled appearance or were polygonal in structure, with actin filaments converged at many points. On the seventh day after heat-shock treatment, actin organization had almost returned to the pre-heat-shock condition, with diffusely distributed actin filaments. In previous studies, we observed such aberrant structures in human malignant keratinocytes and human epidermal keratinocytes treated with 12-O-tetradecanoylphorbol-13-acetate. The observations presented here indicate that those structures are not specific to malignancy or to the process of malignant transformation, but represent less mature and aberrant organizations of actin.
Actin Cytoskeleton↗
Transfer RNA-like structure of the human Alu family: implications of its generation mechanism and possible functions.
Structural resemblance of the human Alu family with a subset of vertebrate tRNAs was detected. Of four tRNAs, tRNA(Lys), tRNA(Ile), tRNA(Thr), and tRNA(Tyr), which comprise a structurally related family, tRNA(Lys) is the most similar to the human Alu family. Of the 76 nucleotides in lysine tRNA (including the CCA tail), 47 are similar to the human Alu family (60% identity). The secondary structure of the human Alu family corresponding to the D-stem and anticodon stem regions of the tRNA appears to be very stable. The 7SL RNA, which is a progenitor of the human Alu family, is less similar to lysine tRNA (55% identity), and the secondary structure of the 7SL RNA folded like a tRNA is less stable than that of the human Alu family folded likewise. Insertion of the tetranucleotide GAGA, which is an important region of the second promoter for RNA polymerase III in the Alu sequence, occurred during the deletion and ligation process to generate the Alu sequence from the parental 7SL RNA. These results suggest that the human Alu family was generated from the 7SL RNA by deletion, insertion, and mutations, which thus modified the ancestral 7SL sequence so that it could form a structure more closely resembling lysine tRNA. The similarities of several short interspersed sequences to the lysine tRNA were also examined. The Galago type 2 family, which was reported to be derived from a methionine initiator tRNA, was also found to be similar to the lysine tRNA. Thus lysine tRNA-like structures are widespread in genomes in the animal kingdom. The implications of these findings in relation to the mechanism of generation of the human Alu family and its possible functions are discussed.
Animals↗
Interleukin 6 and expression of its receptor on epidermal keratinocytes.
Interleukin 6 (IL 6) was detected in the culture supernatants of human epidermal keratinocytes and its production was enhanced by stimulation with cytokines. Production of IL 6 in keratinocytes was demonstrated directly by immunohistochemical staining of cultured cells with anti-IL 6 antibody. Keratinocyte-growth was increased by stimulation with recombinant IL 6 (as measured by either [3H] thymidine uptake or direct cell count). Moreover, expression of IL 6 receptor was demonstrated on monolayered cells, and the deeper cells of stratified keratinocytes in culture by immunohistochemistry. On the other hand, differentiated cells in the upper layers did not express IL 6 receptor on their surfaces, suggesting that the expression of IL 6 receptors may be confined to the proliferative cells. Thus, IL 6, which is produced by epidermal keratinocytes, may be involved in the regulation of normal keratinocyte growth.
Cell Division↗
Construction of NotI restriction map of the Streptococcus mutans genome.
Streptococcus mutans and Streptococcus sobrinus are the major causative organisms of human dental caries. Pulsed-field gel electrophoresis (PFG) showed that the restriction enzyme NotI produced ten and six DNA fragments from the genomes of S. mutans strain MT8148 and S. sobrinus strain 6715, respectively. The sizes of the chromosomes of S. mutans and S. sobrinus were each estimated to be about 2200 kb. The NotI restriction map of S. mutans MT8148 genome was constructed by Southern blot analysis with probes that overlapped two adjacent NotI fragments. Several virulence-associated genes of S. mutans were placed on the NotI restriction map. In addition, unique 'fingerprints' of S. mutans chromosomal DNA digested with NotI were produced by PFG, and these may be useful for epidemiological studies.
Base Sequence↗
Proliferating cell nuclear antigen/cyclin in cultured human keratinocytes.
Expression of proliferating cell nuclear antigen (PCNA)/cyclin in cultured human keratinocytes was studied using an antibody from an SLE patient as the reagent. By indirect immunofluorescence staining, SV40-transformed human keratinocytes expressed PCNA/cyclin in 40-45% of the cells as a nulcear granular fluorescence. After synchronization of these cells, their nuclear distribution pattern during the S phase was sequential and showed a clear correlation with DNA synthesis. Primary cultured keratinocytes grown in high Ca+ medium expressed PCNA/cyclin in 10-15% of the cells with a similar staining pattern. These positively stained cells were confined to the basal and immediate suprabasal layers of the stratified culture sheet. The keratinocytes disaggregated by trypsin were separated according to cell size through a screen of Nitex monofilament cloth. The cells smaller than 15 microns in diameter synthesized abundant PCNA/cyclin, while the larger cells expressed very low levels. These results indicate that the expression of PCNA/cyclin correlates with DNA synthesis in cultured keratinocytes, but is not associated with their differentiation process.
Antigens, Neoplasm↗
Characterization of homologous restriction factor (HRF20) in human skin and leucocytes.
Homologous restriction factor with a molecular weight of 20 kD (HRF20) is a membrane protein that inhibits assembly of the membrane attack complex of homologous complement. Distribution of HRF20 in normal human skin was studied. The plasma membrane of keratinocytes was stained, and the intensity of the staining pattern was higher in the basal cell layer than in the granular layer. Endothelial cells of blood vessels in the dermis were also stained. The molecular weight of HRF20 on erythrocytes and epidermis is 16 kD, determined by Western blot analysis. Those of polymorphonuclear cells and lymphocytes appeared as two bands, a major band of 20 kD and a minor band of 16 kD. Susceptibility of HRF20 to phosphatidylinositol-specific phospholipase C (PIPLC) was examined. After PIPLC treatment of the sections, HRF20 was not detected on the epidermis and was very slightly expressed on the blood vessels. These results indicate that HRF20 attaches to keratinocytes and blood vessels via phosphatidylinositol, regulating the formation of membrane attack complexes of homologous complement on the cell membrane.
Blood Proteins↗
Erythrocytes of patients with paroxysmal nocturnal haemoglobinuria acquire resistance to complement attack by purified 20-kD homologous restriction factor.
A 20-kD homologous restriction factor (HRF20) which is a membrane inhibitor of the terminal stage of human complement action can be detected by the monoclonal antibody 1F5, and is deficient on abnormal erythrocytes as well as leucocytes from patients with paroxysmal nocturnal haemoglobinuria (PNH). The erythrocytes of PNH patients significantly improved their resistance to homologous complement after adsorption of purified HRF20.
CD59 Antigens↗
Carcinosarcoma of the submandibular gland. An autopsy case.
We present a rare case of submandibular gland carcinosarcoma occurring in a 45-year-old male patient. His clinical history revealed that the carcinosarcoma had developed from a carcinoma ex mixed tumor in three years. In spite of repeated resection, intensive chemotherapy and irradiation, the tumor recurred and grew rapidly, and the patient died of hemothorax caused by rupture of a pulmonary metastatic tumor. The fourth recurrent tumor and autopsy specimens showed features of carcinosarcoma consisting of three tumor components, i.e., undifferentiated carcinoma, and chondrosarcomatous and osteosarcomatous growth. The metastatic nodules in both lungs and pulmonary hilar lymph nodes showed the same pattern. Immunohistochemically, the chondrosarcomatous cells were positive for vimentin and S-100 protein, and for epithelial markers such as epithelial membrane antigen (EMA) and cytokeratin (MA-902). Undifferentiated carcinoma cells, on the other hand, were partially positive for muscle actin other than cytokeratin (KL 1). Ultrastructurally, desmosome-like structures were seen in the chondrosarcomatous cells. These findings suggest that the sarcomatous lesions might have originated from epithelial cells.
Actins↗
Structure and expression of the gene coding for a multicopper enzyme, ascorbate oxidase of cucumber.
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Ascorbate Oxidase↗
Growth of human keratinocytes in a defined medium supplemented with growth factor of serum.
In order to prepare a good medium for cultivation of keratinocytes, bovine serum was fractionated by precipitation with various concentrations of ammonium sulfate. The fractionated serum proteins were added to the basal medium at a concentration of 3 mg/ml. The best proliferation was observed in the medium supplemented with the 55-70% ammonium sulfate precipitated fraction. No growth of keratinocytes was observed when the medium was supplemented with the 0-35% fraction. The growth promotion by the 55-70% fraction was completely inhibited by the 0-35% fraction. These results have shown that the fractionation of serum protein clearly separated the growth-inhibitory factors and the growth-stimulating factors.
Blood Proteins↗