The growth inhibition of hepatoma by gene transfer of antisense vascular endothelial growth factor

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis and tumor growth in solid tumors. Therefore, to induce tumor regression, antiangiogenic agents to block VEGF need to be administered repeatedly.

METHOD

We constructed the recombinant mammalian expression vector bearing an antisense-VEGF cDNA, pZeoVEGFa. We examined the effect of pZeoVEGFa on the growth of SK-HEP1 hepatoma cells, bovine capillary endothelial (BCE) cells, and tubule formation of BCE cells in fibrin gel. To evaluate the function of pZeoVEGFa in vivo, we implanted SK-HEP1 hepatoma cells subcutaneously into nude mice.

RESULTS

In SK-HEP1 hepatoma cells, we showed that the synthesis of VEGF protein was suppressed by the stable and transient transfection of pZeoVEGFa. pZeoVEGFa inhibited the proliferation of BCE cells and significantly suppressed tubule formation of BCE cells. pZeoVEGFa inhibited a morphological change from a round shape to an elongated spindle shape in fibrin gel. When pZeoVEGFa was injected peritumorally by liposomes, tumor growth was inhibited.

CONCLUSION

Endothelial cell proliferation, tubule formation and tumor growth may be diminished by down-regulation of endogenous VEGF expression in tumor cells or tissue. These findings indicate that the efficient down-regulation of the VEGF produced by tumor cells using antisense strategies has an antitumor effect. We suggest that VEGF-targeted antiangiogenic gene therapy could be an effective strategy to treat VEGF-producing tumors.

Organo-axial volvulus of the stomach with diaphragmatic eventration

Gastric volvulus occurs when the stomach rotates about its longitudinal axis (organo-axial volvulus), or about an axis joining the lesser and greater curvatures (mesentero-axial volvulus). Primary gastric volvulus, making up one third of cases, occurs when the stabilizing ligaments are too lax as a result of congenital or acquired causes. Secondary gastric volvulus, making up the remainder of cases, occurs in association with a paraesophageal hernia or other congenital or acquired diaphragmatic defects. While gastric volvulus may occur acutely, especially in children, it may not be clinically apparent and discovered incidentally. The authors present a case of chronic organo-axial volvulus of the stomach secondary to left hemidiaphragmatic eventration with a review of the relevant literature.

FGFR3 gene mutation (Gly380Arg) with achondroplasia and i(21q) Down syndrome: phenotype-genotype correlation

We report the case of a boy with achondroplasia and i(21q) Down syndrome. Besides craniofacial features typical in Down syndrome, the skeletal findings of achondroplasia dominate the clinical picture. The diagnosis of Down syndrome was based on clinical features and the cytogenetic finding of i(21q) trisomy 21. The diagnosis of achondroplasia was based on the presence of clinical and radiographic findings and confirmed by the presence of a common FGFR3 gene mutation (Gly380Arg) detected by restriction enzyme analysis and sequencing of the polymerase chain reaction products. This is the first report of achondroplasia associated with i(21q) Down syndrome.

Squamous differentiation downregulates Muc1 mucin in hamster tracheal surface epithelial cell

To investigate whether the squamous differentiation of primary hamster tracheal epithelial cell, which is induced by retinoic acid deficiency or chronic PMA treatment, regulates Muc1 expression, we first produced and characterized a monoclonal antibody against hamster tracheal Muc1 mucin using pGEX-Muc1 fusion protein as an antigen and the changes of Muc1 mucin expression was determined by Western blot. Squamous differentiation downregulated the expression of Muc1 mucin from HTSE cells. The decrease in the immunoreactivity of Muc1 mucin was parallel to the decrease in the immunoreactivity of high molecular weight mucin, which is secreted from HTSE cells. The data from the present study implicate a possible role of Muc1 mucin in squamous differentiation of HTSE cells.

Androgen receptor gene mutation identified by PCR-SSCP and sequencing in 4 patients with complete androgen insensitivity syndrome

To study the genetic defect of the human androgen receptor (hAR) gene in the complete androgen insensitivity syndrome (CAIS), we amplified each of the eight exons by PCR in genomic DNA extracted from the paraffin blocks of the resected gonads. We analyzed using SSCP, and directly sequenced the abnormally shifted bands. Mutations were found in 4 cases of CAIS. Patient 1 carried a point mutation; a G to A transition in exon 7 resulted in a change from arginine to glutamine at codon 831. Patient 2 carried a point mutation; a C to T transition in exon 7 resulted in a change from arginine to stop at codon 831. Patient 3 carried a point mutation and deletion in exon 7. A point mutation was an A to G transition that caused a glutamine to be substituted for the asparagine present at codon 819. A deletion of a G at codon 820 resulted in a frameshift and consequently in the introduction of a premature stop at codon 821. Patient 4 carried a mutation in 5' splice donor site of intron 7; a G to T transition might have caused an abnormal splicing of the exon 7. All of the mutations were found in exon 7. These mutations of hAR gene might be related to the pathogenesis of CAIS.

Construction and characterization of a chimeric receptor containing the cytoplasmic domain of MUC1 mucin

MUC1 mucin is a transmembrane glycoprotein that is highly expressed in various cancer cell lines and is also present in most of the glandular epithelial cells including the airway. Although the presence of numerous phosphorylation sites in its cytoplasmic domain suggests its potential role as a receptor, the unavailability of a ligand for MUC1 mucin has limited our understanding of its function. In this paper, we tried to circumvent this problem by constructing a chimeric receptor containing the cytoplasmic domain of MUC1 mucin, which can be phosphorylated on activation. To this end, we constructed a chimeric plasmid vector (pCD8/MUC1) by replacing the extracellular and transmembrane domains of human MUC1 mucin with those of human CD8. Transient transfection of the vector into COS-7 cells resulted in expression of the chimeric receptor on the surface of the COS-7 cells as judged by immunologic assays with various antibodies as well as by fluorescence-activated cell-sorting analysis. Treatment of the transfected COS-7 cells with an anti-CD8 antibody resulted in a significant increase in phosphorylation of tyrosine moieties of the chimeric receptor. This chimeric receptor will serve as a powerful tool in elucidating the signaling mechanism as well as the functional role of MUC1 mucin in the airway.

Inhaled ATP causes mucin release from goblet cells of intact rats

Secretion of mucins from airway epithelial cells has been studied almost exclusively using in vitro cell culture systems. Our understanding of in vivo secretion is greatly limited due to the unavailability of both suitable model systems and adequate assays. It has been reported that ATP induces mucin release from the cultured primary tracheal surface epithelial cell, but there is no clear demonstration of the effect of ATP on mucin release in vivo, which is important to understand the mechanism of mucin release in vivo and also to devise means for regulation of mucin release. The objective of this experiment was to see if inhaled ATP could stimulate airway mucin release in intact rats using both enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. The results were: (1) a new monoclonal antibody (mAbRT03) developed against purified rat mucins specifically recognized high-molecular-mass mucins; (2) ELISA results with conventional gel-filtration assay results are virtually superimposable; (3) inhalation of ATP in intact rats resulted in a dose-independent increase in the amount of mucins in the tracheal lavage fluid with a concomitant decrease in the number of mucin-positive cells in the trachea. We conclude that extracellular ATP can stimulate mucin release from the airway in vivo, and the present rat inhalation system combined with ELISA of the airway secretions should serve a useful model for studying the pharmacology of airway mucin secretion in vivo.

Nucleotide-induced PMN adhesion to cultured epithelial cells: possible role of MUC1 mucin

Accumulation of intraluminal polymorphonuclear leukocytes (PMN) is a hallmark of inflammatory diseases of the airways. Extracellular nucleotides stimulate PMN adhesion to human main pulmonary artery endothelial cells (HPAEC) by a purinoceptor-mediated mechanism. We investigated the effects of nucleotides on adhesion of freshly isolated human PMN to cultured human tracheobronchial epithelial cells (HBEC). We found that extracellular ATP and UTP were much less effective in stimulating PMN adhesion to HBEC compared with HPAEC, whereas the bacterial chemotactic peptide N-formyl-Met-Leu-Phe stimulated PMN adhesion to both cell types to an equal degree. We investigated several mechanisms that might account for decreased nucleotide-induced PMN adhesion to HBEC. The ectonucleotidase-resistant ATP analog adenosine 5'-O-(3-thiotriphosphate) was also ineffective in stimulating PMN adhesion to HBEC, indicating that degradation of ATP by ectonucleotidase(s) was not responsible for altered PMN adhesion. HBEC responded to ATP and UTP with increased intracellular calcium, indicating that these cells are capable of purinoceptor-mediated responses. We found that ATP and UTP also did not stimulate PMN adhesion to Chinese hamster ovary (CHO) cells, which had been stably transfected with the gene for hamster Muc1, a cell-associated mucin. However, ATP and UTP did stimulate adhesion of PMN to nontransfected CHO cells. These results suggested that MUC1 mucin modulates PMN adhesion to epithelium. We found that cultured HBEC expressed more mRNA and protein for MUC1 mucin than did HPAEC. We conclude that extracellular nucleotides are less effective in stimulating PMN adhesion to epithelial cells than to endothelial cells and that overexpression of hamster Muc1 mucin inhibits nucleotide-induced PMN adhesion to CHO cells.

Inhibition of mucin release from airway goblet cells by polycationic peptides

In the present study, we investigated whether polycationic peptides affect mucin release from cultured airway goblet cells. Confluent primary hamster tracheal surface epithelial cells were metabolically radiolabeled with [(3)H]glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of either poly-L-arginine (PLA) or poly-L-lysine (PLL) to assess the effects on [(3)H]mucin release. Possible cytotoxicity by the polycations was assessed by measuring lactate dehydrogenase release, (51)Cr release, and cell exfoliation. The results were as follows: 1) both PLA and PLL inhibited mucin release in a dose-dependent fashion; 2) there was no significant difference in either lactate dehydrogenase release, (51)Cr release, or the number of floating cells between control and treatment groups; 3) the effects of both PLA and PLL on mucin release were completely blocked by neutralizing the positive charges either by pretreatment with heparin or by N-acetylation of the polycations; and 4) both PLA and PLL completely masked the stimulatory effect of ATP on mucin release. We conclude that these polycationic peptides can inhibit mucin release from airway goblet cells without any apparent cytotoxicity, and the inhibitory effect seems to be attributable to their positive charges. These are the first nonsteroidal agents, to the best of our knowledge, that have been shown to inhibit mucin release from airway goblet cells.

A monoclonal antibody against hamster tracheal mucin, which recognizes N-acetyl-galactosamine containing carbohydrate chains as an epitope

Airway mucin that is present in airway secretion, plays an important role in host-defense by trapping airborne particles and removing them by mucociliary transport system. For the study of mucin, it is crucially important to have antibodies specific against mucin because other commonly used methods such as histologic stain for the detection of mucin usually suffer from varying levels of nonspecificity. In this study, we produced a monoclonal antibody (MAb) against hamster airway mucin, which is one of the most commonly used animal species for the study of mucin in vitro, and characterized its immunological properties along with the determination of the epitope it recognizes. The MAb, which was named MAb HTA, was IgM isotype and specific against mucin from both in vitro cell culture and in vivo airway secretion. In Western blot, MAb HTA specifically recognized high molecular weight airway mucin, which was also confirmed by the appearance of peak profile of immunological signal only on void volume fraction in Sepharose CL-4B gel filtration chromatography. It also immunoprecipitated high molecular weight hamster airway mucin with the aid of antimouse IgM agarose. In immunohistochemical stain of hamster trachea, it showed strong signal on airway epithelium and also on the mucin secreting goblet cell granules. The immunological signal was greatly increased by the treatment of endotoxin, which has been reported to cause airway secretory cell metaplasia. The MAb HTA recognized carbohydrate chains containing N-acetyl-galactosamine, one of the linking sugars of airway mucin, as an epitope. Treatment of mucin with N-acetyl-galactosaminidase caused great reduction of immunological signal. To the best of our knowledge, this is the first to report a MAb that recognizes N-acetylgalactosamine, a linking sugar of airway mucin. The specificity of MAb HTA against airway mucin and the clear demonstration of the epitope it recognizes should greatly aid the pharmacological and biochemical study of mucin in various physiological and pathological situations.

Ganoderma lucidum extract protects DNA from strand breakage caused by hydroxyl radical and UV irradiation

The fruit bodies of Ganoderma lucidum have been used for the prevention and treatment of various diseases in the Orient. Its antitumor and immune enhancing properties, along with no cytotoxicity, raise the possibility that it could be effective in preventing oxidative damage and resulting disease. Using agarose gel electrophoresis, we have evaluated the potential of Ganoderma lucidum extract as a radioprotector and antioxidant defense against oxygen radical-mediated damage. Although the evidence presented here is based on in vitro using isolated DNA, the results clearly demonstrate that the hot-water extract of Ganoderma lucidum shows good radioprotective ability, as well as protection against DNA damage induced by metal-catalyzed Fenton reactions and UV irradiation. We also found that the water-soluble polysaccharide isolated from the fruit body of Ganoderma lucidum was as effective as the hot-water extract in protecting against hydroxyl radical-induced DNA strand breaks, indicating that the polysaccharide compound is associated with the protective properties. Our data suggest that Ganoderma mushroom merits investigation as a potential preventive agent in humans.

Noradrenaline synchronizes evoked quantal release at frog neuromuscular junctions

1. Noradrenaline (NA) increases synaptic efficacy at the frog neuromuscular junction. To test the hypothesis that one of the actions of NA is to shorten the period over which evoked quanta are released, we measured the latencies of focally recorded uniquantal endplate currents (EPCs). 2. NA shortened the release period for evoked quantal release. The interval between the time when responses with minimal delay appeared and the point at which 90 % of all latencies had occurred was shortened in the presence of 1 x 10-5 M NA by about 35 % at 20 C and by about 45 % at 8 C. Inhibitor and agonist experiments showed that NA acts on a beta-adrenoreceptor. 3. The better synchronization of release significantly increased the size of reconstructed multi- quantal EPCs. This suggests that NA facilitates synaptic transmission by making the release of quanta more synchronous. 4. The synchronizing action of NA might potentiate neuromuscular transmission during nerve regeneration, transmitter exhaustion and other extreme physiological states where the quantal content is reduced, such as survival in cold and hibernation.

Visual impairment and REP-1 gene mutations in Japanese choroideremia patients

Choroideremia (CHM), an X-linked recessive hereditary disease, is an intractable chorioretinal dystrophy. The rate of disease progression of CHM reportedly shows considerable variability. A number of mutations involving the gene that codes for Rab escort protein-1 (REP-1) have been detected in CHM patients. We have analyzed REP-1 gene mutations of Japanese CHM patients. The present study was designed to investigate the clinical variability and the genotype to phenotype relationship in 15 Japanese CHM patients referred to the Department of Ophthalmology of Juntendo University Hospital. The clinical investigation of visual acuity, visual field, color vision and refraction revealed inter-individual variability. Mutation analyses of the REP-1 gene revealed 10 types of mutations in 13 patients from 11 families, including an insertion, small deletions, nonsense mutations and an A to CC mutation. In 13 CHM patients with detectable REP-1 gene mutations, no relationship of genotype to phenotype was detected. At present, we consider the REP-1 genotype to be an unreliable prognostic factor for counseling of CHM patients. In two patients from one family, no mutations were detected in coding regions of the REP-1 gene. These patients may have intron mutations of the REP-1 gene, not detectable by the techniques employed in this study, or other causative genes. Both were observed to have somewhat slower disease progression than the other 13 patients. More advanced analyses are necessary to answer questions regarding the genotype-phenotype relationship in CHM patients.

Two eosinophil granule proteins, eosinophil peroxidase and major basic protein, inhibit mucin release from hamster tracheal surface epithelial cells in primary culture

OBJECTIVES AND DESIGN

Effects of eosinophil proteins on airway goblet cell mucin release were investigated using primary hamster tracheal surface epithelial (HTSE) cell cultures.

MATERIALS AND METHODS

HTSE cells were metabolically labeled using 3H-glucosamine and chased in the presence of varying concentrations of eosinophil proteins. The amount of 3H-mucin in the spent media was measured by Sepharose CL-4B gel-filtration column chromatography. Possible cytotoxicity by the eosinophil proteins was assessed by measurements of both lactic dehydrogenase and mucin release during as well as after the treatment period.

RESULTS

(1) Neither eosinophil cationic protein nor eosinophil-derived neurotoxin affected mucin release at concentrations up to 10(-6) M; (2) both major basic protein (MBP) and eosinophil peroxidase (EPO) inhibited mucin release in a dose-dependent fashion, and the inhibitory effect by these proteins appeared to be reversible; (3) neither MBP nor EPO caused any apparent cytotoxicity at concentrations up to 10(-6) M.

CONCLUSION

Eosinophil proteins such as MBP and EPO inhibit mucin release from primary HTSE cells without causing any apparent cytotoxicity.

Novel and recurrent COMP (cartilage oligomeric matrix protein) mutations in pseudoachondroplasia and multiple epiphyseal dysplasia

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) are common skeletal dysplasias with impaired enchondral ossification and premature degenerative joint disease. The two disorders were in the past considered to be distinct clinical entities; however, recent studies have proven that both diseases can result from mutations of the gene encoding cartilage oligomeric matrix protein (COMP). To characterize further COMP mutations and investigate phenotype-genotype relationships, we screened this gene in 15 patients with PSACH or MED by directly sequencing polymerase chain reaction products from genomic DNA. We identified ten mutations involving conserved residues among the eight calmodulin-like repeats of the gene product: seven were novel missense mutations in exons 9, 10, 11, 13 or 14, and the other three resulted from deletion of one of the five GAC repeats in exon 13. We have found that the GAC repeats in the 7th calmodulin-like repeat in exon 13 represent a hot-spot for mutation, and that mutations in the 7th calmodulin-like repeat produce severe PSACH phenotypes while mutations elsewhere in the gene exhibit mild PSACH or MED phenotypes. These genotype-phenotype correlations may facilitate molecular diagnosis and classification of PSACH and MED, and provide insight into the relationship between structure and function of the COMP gene product.

Identification and characterization of high molecular-mass mucin-like glycoproteins in the plasma membrane of airway epithelial cells

A previous lectin binding study demonstrated the presence of high molecular-mass mucin-like glycoproteins (HMGP) on the surface of hamster tracheal surface epithelial (HTSE) secretory cells (Proc. Natl. Acad. Sci. USA 1987;84:9304). In the present study, we intended to isolate and characterize these HMGP from the plasma membrane of the primary HTSE cells and then to determine whether or not these membrane HMGP are Muc-1 mucins, a type of mucins originally discovered on the surface of some carcinomas. A subcellular fraction enriched with the plasma membrane was obtained using a sucrose density gradient centrifugation. This fraction contained high molecular-mass glycoconjugates which were excluded from Sepharose CL-4B gel. Biochemical characterization of these glycoconjugates revealed the following characteristics: (1) susceptibility to both pronase and mild alkaline treatments, but totally resistant to proteoglycan-digesting enzymes; (2) partitioning in the detergent phase of Triton X-114 and resistance to digestion by phosphatidylinositol phospholipase C or D; (3) a buoyant density of 1.5 g/ml based on CsCl density gradient centrifugation; (4) polydispersity in terms of both size and charge density; and (5) lack of immunoreactivity with an anti-Muc-1 mucin antibody. We conclude that the plasma membrane of HTSE cells at confluence contains HMGP, which seem to be the integral membrane proteins but different from Muc-1 mucins, and that these membrane HMGP appear to share some similarities with secreted mucins in terms of size and charge.

Thiol-linked peroxidase activity of human ceruloplasmin

Human ceruloplasmin exhibited different antioxidant effects according to the electron donors in a metal-catalyzed oxidation system. Purified ceruloplasmin did not play a significant role in the protection of DNA strand breaks in the ascorbate/Fe3+/O2 system. However, when ascorbates were replaced with a thiol-reducing equivalent such as dithiothreitol, DNA strand breaks were significantly prevented by the same amount of ceruloplasmin. Ceruloplasmin did not catalyze the decomposition of H2O2 in the absence of reduced glutathione. On the contrary, ceruloplasmin showed a potent peroxidase ability to destroy H2O2 in the presence of reduced glutathione. In conclusion, the removal of H2O2 by human ceruloplasmin is not simply stoichiometric but thiol-dependent.

Minute chromosomal rearrangements detected prenatally by fluorescence in situ hybridization

Initial approaches to prenatal diagnosis from fetal karyotyping involved application of standard cytogenetic techniques. However, when fetal samples, such as chorionic villus cells or amniocytes are used, small chromosome rearrangements cannot be easily identified because they lack a distinct banding pattern. We report here two cases with minute chromosome rearrangements detected prenatally by fluorescence in situ hybridization. The use of this technique allowed precise identification of fetal chromosome abnormalities, demonstrating its usefulness for characterizing conditions that would be difficult to diagnose correctly with conventional banding methods alone.

Development of a competitive enzyme linked immuno sorbent assay to measure ceruloplasmin in gamma-irradiated rat serum

The concentrations of ceruloplasmin could not be determined by comparing the oxidase activities toward p-phenylenediamine and o-dianisidine in rat whole serum with those of purified ceruloplasmin because of the different specific amine oxidase activities of ceruloplasmin purified from normal and gamma-irradiated rats and the lability caused by freezing and thawing. A competitive enzyme linked immunosorbent assay with antigens immobilized on the solid phase was developed to measure the ceruloplasmin in rat serum. The blocking materials and pH of the coating buffer had an effect on the amount of ceruloplasmin bound to the microtiter plates. The blocking materials nonspecifically reacted with the rabbit anti-rat ceruloplasmin IgG, and consequently the coating sensitivity was decreased and standard curves were not formed completely. Because rabbit anti-rat ceruloplasmin IgG did not show any cross reactivity with rat albumin and hemoglobin, these proteins did not affect the assay at a concentration of 200 micrograms/ml. This assay is useful for measuring the concentration of ceruloplasmin in normal and irradiated rat serum.

Syntheses of two enantiomeric pairs of myo-inositol(1,2,4,5,6) and -(1,2,3,4,5) pentakisphosphate

Two enantiomeric pairs of myo-inositol(1,2,4,5,6)P5 and -(1,2,3,4,5)P5 have efficiently been synthesized by means of the lipase catalyzed acetylation of 1,2:5,6-di-O-isopropylidene-myo-inositol and the benzoyl migration procedure.

Production and characterization of monoclonal antibodies against rat tracheal mucins

The objective of this study was to generate and characterize monoclonal antibodies against rat airway mucins. Therefore, it should serve as a useful tool in studying the regulation of airway mucins using various in vivo rat models that are currently available. As an antigen, we used a high molecular mass mucin preparation purified from the spent media of rat tracheal surface epithelial cells in primary culture. Seven monoclonal hybridomas were obtained, among which mAbRT03 showed the highest immunoreactivity against the mucin. All of the antibodies secreted by these hybridomas recognized carbohydrate epitopes but not sialic acid residues, since their immunoreactivity was completely abolished by treatment of the mucin with 20 mM periodate but not with neuraminidase. Further characterization of mAbRT03 showed that (1) it belongs to the IgM type, (2) it binds to high molecular mass mucins based on Western blot, (3) it could indirectly immunoprecipitate rat airway mucin--and, as we know, this is the first demonstration of immunoprecipitation of airway mucin with anti-mucin antibodies--(4) it binds to the luminal side of tracheal epithelium as well as some goblet cells based on immunohistochemistry, and (5) it also recognizes in vivo airway mucins from rats, but not from human nor hamsters, which have been purified from the airway lavage fluids. This is the first monoclonal antibody against rat airway mucin, which has been developed against purified rat airway mucins. Therefore, mAbRT03 should be able to serve as an invaluable tool in studying the regulation of airway mucins using various intact rat models that are currently available.

Comparison between ELISA and gel-filtration assay for the quantitation of airway mucins

In this study, we developed immunoassay methods for the more convenient and effective detection of rat tracheal mucin and the results were compared with those of [3H]glucosamine based gel-filtration method. A monoclonal anti-rat tracheal mucin antibody, mAbRT03, which specifically recognizes rat tracheal mucins, was used throughout in this study. To induce mucin secretion, varying concentrations of ATP (0-2 mM) were applied to the primary rat tracheal surface epithelial (RTSE) cell culture which had been metabolically radiolabeled with [3H]glucosamine and the secretion of mucin was analyzed both by the immunoassay and the gel-filtration chromatography methods. For the immunoassay, the following two procedures were employed. 1) Simple ELISA; the culture spent media were directly coated onto the assay plate and the immunoreactivity with mAbRT03 was assessed from the standard curve generated with the purified rat mucin. 2) Inhibition ELISA; A known amount of the purified rat mucin was coated onto the assay plate and then ATP-stimulated culture spent media were added to inhibit the immunoreactivity with mAbRT03. The contents of mucin in the sample were calculated from the standard inhibition curve which was generated with the purified rat mucin. The assay results obtained from the immunoassays were identical with those from the gel-filtration methods. The present result indicates that ELISA can be substituted for the laborious, time-consuming gel-filtration assay in studying the regulation of airway mucin release from cultured airway epithelial cells.

HDR syndrome (hypoparathyroidism, sensorineural deafness, renal dysplasia) associated with del(10)(p13)

A combination of hypoparathyroidism, sensorineural deafness, and renal dysplasia has been considered to be a new syndrome inherited in an autosomal dominant fashion; we name the condition "HDR syndrome." We describe a Japanese girl who has HDR syndrome associated with de novo del(10)(p13). The chromosome deletion suggests that the putative gene(s) responsible for HDR syndrome is located at a 10pter-->p13 region.

Airway goblet cell mucin: its structure and regulation of secretion

Mucociliary clearance is a major function of the airway epithelium. This important function depends both on the physicochemical properties of the airway mucus and on the activity of the cilia. The former, in turn, is dependent mainly on the quality and quantity of mucous glycoproteins or mucins, which are produced by two different cell types, namely, goblet cells of the epithelium and mucous cells of the submucosal gland. Neither the structural nor the functional differences of mucins produced by these two cell types are yet known. The availability of primary airway epithelial cell culture systems, however, has made it possible to study the structure and regulation of airway goblet cells to some extent. The epithelial mucins are extremely hydrophobic and are associated with various macromolecules, the quality and quantity of which may also affect the physicochemical properties of the mucus. Secretion of epithelial mucins is stimulated by various factors, including a number of inflammatory agents. The recent progress in mucin molecular biological research will allow us to identify different mucin core proteins produced by those different cell types, and, hopefully, the differential functions of these mucins in health and disease.

Possible narrowed assignment of the loci of monosomy 21-associated microcephaly and intrauterine growth retardation to a 1.2-Mb segment at 21q22.2

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Structure and expression of the AWI 31 gene specifically induced by wounding in Arabidopsis thaliana

Differential screening of an Arabidopsis cDNA library constructed from the plant tissues harvested 1 h after wounding resulted in the isolation of wound-inducible cDNA clones (Kim et al., 1994). The cDNA clones could be broadly classified into two groups according to the expression time of their transcripts. Nine clones from the 10 different wound-inducible cDNAs were rapidly induced, reaching a maximum level in approximately 1-1.5 h and then were progressively reduced after wounding. The cDNA clone AWI 31 showed steady accumulation of the transcripts and reached the maximum value at a later time point of 2.5 h and then started to decline. The corresponding gene of the AWI 31 in which the coding region was interrupted by an intron, had an open reading frame that predicted a protein of 386 amino acids. However, the gene product did not show any significant homology to other known proteins in the database. Northern hybridization study using the cDNA probe revealed that the gene was not regulated by other environmental stresses such as drought, high salt, low temperature, or a DPE herbicide treatment, indicating that the cDNA clone AWI 31 was specifically induced by wounding.

ATP-induced mucin release from cultured airway goblet cells involves, in part, activation of protein kinase C

Extracellular nucleotides stimulate mucin release by binding to the P2u receptor coupled to phospholipase C via G proteins (Br. J. Pharmacol. 103:1053-1056, 1991; Am. J. Respir. Cell Mol. Biol. 8:121-125, 1993). In the present study, we intended to investigate pathways downstream to the phospholipase C activation which is responsible for adenosine triphosphate (ATP)-induced mucin release in hamster tracheal epithelial cells in primary culture. We have found that: (1) Ca2+ ionophores (A23187 and ionomycin) did not affect mucin release even at 1 microM; (2) thapsigargin (10 microM), either alone or in combination with ATP (20 microM), did not enhance mucin release over its respective control group; (3) pretreatment of hamster tracheal surface epithelial (HTSE) cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM) (50 microM) did not inhibit ATP-induced mucin release; (4) 4beta-phorbol 12alpha-myristate 13-acetate (PMA, 1 microM) stimulated mucin release and its effect was completely blocked by protein kinase C inhibitors such as sphingosine (10 microM) and calphostin C (0.1 microM), whereas ATP-induced mucin release was blocked, only in part, by these inhibitors; (5) desensitization of protein kinase C by pretreatment with PMA inhibited the PMA-induced mucin release completely, however, ATP-induced mucin release was inhibited only partially. We conclude that mucin release by ATP does not require an increase in the intracellular Ca2+ level but involves the activation of protein kinase C. The results also suggest the presence of another mechanism separate from the phospholipase C-protein kinase C pathway for the ATP-induced mucin release.

Tetramelic mirror-image polydactyly and a de novo balanced translocation between 2p23.3 and 14q13

We report on a male infant with tetramelic mirror-image polydactyly and a de novo, balanced reciprocal translocation between 2p23.3 and 14q13. This patient suggests that a novel gene, which functions in the morphogenesis of the hands and feet along the anterior-posterior axis, may be located at 2p23.3 or 14q13.

Expression of MUC1 mucin gene by hamster tracheal surface epithelial cells in primary culture

Primary hamster tracheal surface epithelial (HTSE) cells carry mucin-like glycoproteins on the apical surface which are releasable by neutrophil elastase. In some cancer cells, mucins are localized on the cell surface and have been shown to be encoded by the MUC1 mucin gene. The objectives of the present experiments were: (I) to determine if HTSE cells express MUC1 mucin gene; (2) if they do, to isolate and characterize the hamster MUC1 complementary DNA (cDNA); and (3) to examine the pattern of MUC1 mRNA expression at different stages of culture. Reverse transcriptase-polymerase chain reaction amplification of HTSE cell RNAs using degenerate primers based on homologous sequences between the human and mouse MUC1 genes revealed the presence of a cDNA (0.5 kb) which has an 88% similarity in sequence with the mouse MUC1 cDNA. Using this 0.5 kb cDNA as a probe, an HTSE cell cDNA library was screened to isolate a hamster MUC1 cDNA clone. Sequence analysis of the cDNA revealed that it encodes an integral membrane protein of 676 amino acids which consists of (1) an N-terminal signal sequence, (2) the tandem repeat domain encoding 12 repeats of 20 amino acids, and (3) the C-terminal region consisting of degenerate tandem repeats and a unique sequence containing both the transmembrane and cytoplasmic domains. The presence of seven tyrosine residues in the cytoplasmic domain suggests a potential role as a receptor. Finally, expression of MUC1 mucin gene in HTSE cells appears to be associated with differentiation of secretory cells.

Anorectal dysfunction in systemic sclerosis

This study was aimed to evaluate the anorectal dysfunction in systemic sclerosis (SSc) and propose the clinical significance of anorectal manometry in patients with SSc. Seven patients with SSc were evaluated with manometry for anorectal function and an additional 11 normal subjects were collected as a control group. The study group underwent esophageal manometry as well and the correlation between the degree of anorectal and esophageal dysfunction was evaluated. Patients showed a lower tolerance for balloon distention of the rectum than controls (minimal sensory volume and urgency volume, P < 0.05). The resting and squeezing pressure of the anal sphincter and the functional length of the anal canal showed no significant difference in these two groups. Rectoanal inhibitory reflex was absent in one (14%) and diminished in two (29%) of seven patients with SSc. SSc patients also showed abnormal esophageal manometry findings, notably decreased LES pressure and body amplitude of distal 2/3 esophagus. The comparison between manometric profiles of anorectum and esophagus showed no significant correlation by statistical analysis. In conclusion, our data could suggest that anorectal function may be impaired in patients with SSc which could reflect the involvement of the anorectum by the disease, and that anorectal manometric studies can be useful to detect such dysfunction in patients with SSc, even before clinical symptoms.

A case of flutamide-induced acute cholestatic hepatitis--a case report

Flutamide, an oral nonsteroidal, antiandrogenic, anilid compound which inhibits the uptake and binding of androgens to nuclear receptors in the prostate, is used with or without LH-RH analogues for treatment of patients with metastatic carcinoma of the prostate. Clinically significant hepatotoxicities such as toxic hepatitis, cholestatic hepatitis, hepatic failure, and even death have rarely been reported in the English literature, but no case has been reported in Korea. A 75-year-old man with metastatic carcinoma of the prostate had taken flutamide (750 mg/day) for 7 months and suddenly developed jaundice and general weakness. The findings of blood chemistries were compatible with cholestatic hepatitis, but ultrasonography, viral marker and auto-antibody studies did not reveal any attributable causes. Histologic examination of a sono-guided liver biopsy only disclosed centrilobular cholestasis, nuclear glycogenosis and mild sinusoidal lymphocytic infiltration. Discontinuation of flutamide resulted in an almost full recovery of the patient's liver function in 2 months. We, herein, report a case of flutamide-induced acute choestatic hepatitis with a brief review of the literature.

A case of paraesophageal hernia repaired by laparoscopic approach

Paraesophageal hernia comprises only 2 approximately 5% of all hiatal hernias but is prone to incarceration and strangulation. For this reason they must be recognized and repaired as expeditiously as possible. The laparoscopic approach has already been successfully applied to the repair of the more common sliding hiatal hernia and it seems reasonable to propose that the paraesophageal hernia, provided it is not complicated, might also be repaired by the laparoscopic technique. We present here a case of paraesophageal hernia which has been successfully repaired by the laparoscopic approach. A 73-year-old female suffering from postprandial fullness in the retrosternal area was diagnosed preoperatively with paraesophageal hiatal hernia with gastroesophageal acid reflux and was submitted for laparoscopic repair. The procedure entailed reduction of the hernia, mobilization of the esophagogastric junction with crural repair and partial fundoplication. At the 9th-month follow-up, the patient had remained asymptomatic and follow-up studies revealed no evidence of hernia or acid reflux. As a result of this favorable experience with minimal morbidity, early hospital discharge, and effective control of symptoms without adverse sequalae, laparoscopic repair can be considered as the curative and minimal invasive method in the management of paraesophageal hernia.

Nucleotide-induced mucin release from primary hamster tracheal surface epithelial cells involves the P2u purinoceptor

Mucin release by airway surface epithelial cells is regulated by extracellular adenosine triphosphate (ATP) via a P2 purinoceptor-mediated mechanism. The objective of the present experiment was to examine the possible involvement of uridine triphosphate (UTP) in this purinergic signal transduction pathway. Using primary hamster tracheal surface epithelial cells, ATP and UTP were compared in their abilities: 1) to displace ATP gamma S35-binding to intact cells; 2) to accumulate inositol phosphates; and 3) to stimulate mucin release. Finally, the presence of a P2u receptor message was examined. Our results showed that: 1) UTP was much less effective than ATP in displacing ATP gamma S35-binding (median inhibitory concentrations (IC50S) 240 vs 2.9 microM); 2) UTP was more potent than ATP in accumulating inositol phosphates (100 vs 43% increase at 2mM); 3) UTP was equipotent with ATP in stimulating mucin release; 4) Northern blot analysis of messenger ribonucleic acids (mRNAs) with a mouse P2u receptor complementary deoxyribonucleic acid (cDNA) probe revealed a single specific band (2.8 kb), partial sequencing of which showed a great homology with those of human or mouse P2u receptors. We conclude that, although both ATP and UTP are equipotent in stimulating mucin release, their binding kinetics to the cell surface are quite different, suggesting the presence of a common binding domain which may be responsible for the mucin release by these nucleotides. We suggest that the P2u purinoceptor is likely to be responsible for mucin release by these nucleotides, probably via activation of phospholipase C.

Metabolism of capsaicinoids: evidence for aliphatic hydroxylation and its pharmacological implications

A new metabolic oxidation pathway of capsaicin (N-[(4-hydroxy-3-methoxyphenyl)-methyl]-8-methyl-(E)-6 -nonenamide), a major pungent and pharmacologically active principle of hot peppers, was investigated. Incubation of capsaicin with phenobarbital-induced rat liver postmitochondrial supernatant enriched with NADPH-generating system produced N-(4,5-dihydroxy-3-methoxybenzyl)-(E)-6 -nonenylamide and a more polar metabolite. The latter metabolite was spectrophotometrically and chromatographically identical to authentic omega-hydroxycapsaicin. This new metabolite was also detected in the urine of rabbits given capsaicin by gastric intubation. Other analogs of capsaicin, such as dihydrocapsaicin and nonivamide, also formed similar metabolites via aliphatic hydroxylation. When tested for antinociceptive activity as well as pungency, the above polar metabolites were found to be inactive while their parent compounds exhibited strong sensory effects. Capsaicin interacted irreversibly with heptic drug metabolizing enzymes, thereby inhibiting their activity as indicated by prolongation of pentobarbital sleeping time in rats. Such inhibition of drug metabolism was not observed with omega-hydroxycapsaicin. These findings suggest that metabolism of capsaicinoids via hydroxylation of their side chains plays an important role in the detoxification of these pharmacologically active substances.

Purification and characterization of adipocyte heparan sulfate proteoglycans with affinity for lipoprotein lipase

Lipoprotein lipase (LPL)-binding heparan sulfate proteoglycans (HSPGs) were isolated from cell extracts and conditioned media of cultured adipocytes treated with phosphatidylinositol-specific phospholipase C (PIPLC). The methodology employed included anion exchange chromatography, affinity chromatography on LPL Affi-Prep 10 and hydrophobic chromatography. HSPGs were resolved into two distinct fractions on the Octyl-Sepharose CL-4B matrix. Treatment of the eluted fractions with heparinase and heparitinase yielded core proteins of 48.4 and 39 kDa. The 39-kDa core protein is anchored to the cell surface by a glycosyl phosphatidylinositol anchor as evidenced by 1) release of the HSPG with the 39-kDa core protein into media by PIPLC treatment and 2) biosynthetic incorporation of [3H]ethanolamine and [32P]orthophosphate into the PIPLC-releasable 39-kDa core protein. PIPLC released 23% of the total heparin-releasable LPL. A similar percentage (24.5%) of the total heparan sulfate chains was released by PIPLC. Over 96% of the total adipocyte heparan sulfate chains bound to LPL Affi-Prep 10 column. The heterogeneity of core proteins of HSPGs with affinity for LPL may provide a structural basis for the multiple fates of LPL on the surface of adipocytes, i.e. internalization, degradation, or recycling to the cell surface and translocation into the medium.

Isolation and characterization of two cDNA clones that are rapidly induced during the wound response of Arabidopsis thaliana

Differential screening of a cDNA library of Arabidopsis thaliana constructed from the plant tissues harvested 1 h after wounding resulted in isolation of 2 wound-inducible cDNA clones. Kinetic analysis revealed that the corresponding genes are rapidly induced upon wounding. Expression of these clones reached the maximum level around 1-1.5 h after wounding and then were progressively reduced. The time by which expression returned to the control level was around 3 h after wounding. Partial sequence analysis revealed that the two clones are highly homologous to the S-adenosylmethionine synthetase and the glutathione-S-transferase gene, respectively.

Binding kinetics of ATP gamma S35 on cultured primary tracheal surface epithelial cells

Extracellular ATP can stimulate mucin release from primary hamster tracheal surface epithelial (HTSE) cells via a P2 purinoceptor-mediated mechanism, based on agonist potency studies of mucin release (Br. J. Pharmacol. 1991; 103:1053-1056). In the present study, we examined the kinetics of ATP binding to the surface of intact HTSE cells at 4 degrees C using ATP gamma S35 as a radioligand. We found that ATP gamma S35 bound to HTSE cells in a saturable, reversible manner, reaching an equilibrium at about 30 min. Scatchard analysis of equilibrium binding suggested the presence of two binding sites with Kd values of 0.47 and 9.4 microM. Competitive binding experiments, based on the ability of nucleotides and ATP analogs to block ATP gamma S35 revealed a rank order of ATP > ADP > alpha,beta-methylene ATP > 2-methylthio ATP > or = beta, gamma-methylene ATP. Neither AMP nor adenosine could inhibit the ATP gamma S35 binding. A comparison between the ability of nucleotides to compete with ATP gamma S35 binding and their ability to induce mucin release revealed a rather poor correlation (r2 = 0.67) with all of the above nucleotides but a good correlation (r2 = 0.96) without 2-methylthio ATP, indicating the presence of heterogenous ATP binding sites on the HTSE cell surface. UTP, a pyrimidine nucleotide, which is almost equipotent with ATP in its ability to stimulate mucin release, was much less potent than ATP in its ability to displace the ATP gamma S35 binding in these HTSE cells.

Effect of floating a gel matrix on mucin release in cultured airway epithelial cells

Confluent cultures of primary hamster tracheal surface epithelial (HTSE) cells grown on a thick collagen gel are highly enriched with secretory cells and constitutively release mucins. In the present experiment, we examined the possible effect of mechanical strain of cultured HTSE cells on the release of mucin. The mechanical strain of cells was accomplished by several methods: 1) by floating the gel from the culture dish by rimming; 2) by treatment with EGTA which interrupts intercellular tight junctions; 3) by treatment with collagenase which disrupts the cell-matrix adhesion; and 4) by mechanically flexing the collagen gel matrix. All these conditions caused increases of mucin release without damage on the plasma membrane. We conclude that a number of mechanical strains which might alter cell shape can stimulate mucin release from cultured HTSE cells. Such a mechanism might be operative in the physiological regulation of airway goblet cell mucin secretion where mechanical strains may be induced on epithelial cells by underlying smooth muscles.

Extension of the range of Dermacentor variabilis (Acari: Ixodidae) in Pennsylvania

The American dog tick, Dermacentor variabilis (Say), until recently was recorded only from the southeastern and southwestern counties of Pennsylvania. Since 1968, this species has expanded its range and is reported from 63 of Pennsylvania's 67 counties. This range extension is a matter of concern to the medical community and to physicians throughout Pennsylvania, particularly those with practices in areas where this tick was previously unknown and who may not be familiar with the symptoms of Rocky Mountain spotted fever.

Involvement of a signal transduction mechanism in ATP-induced mucin release from cultured airway goblet cells

Release of mucins from cultured airway surface epithelial cells can be stimulated by extracellular ATP via a P2-purinergic receptor-mediated mechanism (K. C. Kim and B. C. Lee. 1991. Br. J. Pharmacol. 103:1053-1056). In this report, we studied the mechanism by which extracellular ATP induces the mucin release. We found that: (1) ATP increased both mucin release and generation of inositol phosphates in a dose-dependent fashion, and their dose-effect relationships were almost superimposed; (2) the increases in both mucin release and the phosphatidylinositol phosphate (PI) turnover by extracellular ATP were partially, but almost equally, blocked by the pretreatment with pertussis toxin (42% for mucin release and 44% for PI turnover). We conclude that in cultured airway goblet cells extracellular ATP stimulates mucin release by a signal transduction mechanism, which seems to involve coupling of ATP-activated P2 purinoceptors with phospholipase C, at least in part, via pertussis toxin-sensitive GTP-binding proteins. This may be an important finding in understanding the regulation of mucin release by airway goblet cells, since a number of agents present in the airway could influence this signal transduction pathway and subsequently modulate the mucin secretion.

Filial piety and intergenerational relationship in Korean immigrant families

This article examines the changing nature of socio-economic conditions for Korean immigrants, which strain their intergenerational relationships in the United States. As the family-kinship system of Korean immigrants changes toward the conjugal family, it is contended that their traditional expectation of filial piety should be modified. The problems in fulfilling the traditional expectation of filial piety and the nature of the modified expectation of filial piety are discussed.

P2 purinoceptor regulation of mucin release by airway goblet cells in primary culture

1. The effects of adenine analogues on mucin release by airway goblet cells have been examined in a hamster primary tracheal epithelial cell culture. 2. Adenosine, a P1 receptor agonist, had no effect on mucin release even at 2 mM, while ATP, a P2 receptor agonist, stimulated mucin release in a dose-dependent fashion with an apparent EC50 of 20 microM. The relative potency order among adenine nucleotides was ATP greater than ADP greater than AMP = adenosine. 3. ATP gamma S, a non-hydrolyzable analogue of ATP, was equipotent with ATP in stimulating mucin release. The potency order among some ATP analogues was ATP greater than 2-methylthio ATP greater than alpha, beta-methylene ATP greater than beta, gamma-methylene ATP. Reactive blue 2, a putative P2 gamma-purinoceptor antagonist, did not block the ATP-induced mucin release. 4. The present results indicate that mucin release by airway goblet cells is stimulated by extracellular ATP via P2 receptor-mediated mechanism. We suggest that this mechanism may be important in the physiological regulation of airway goblet cell mucin release in vivo.