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1.
Transbound Emerg Dis ; 61(6): e76-8, 2014 Dec.
Article in English | MEDLINE | ID: mdl-23347360

ABSTRACT

An 8-month-old crossbred ewe, normal upon physical examination, was humanely euthanized for tissue collection. After approximately 3 weeks in tissue culture, fungi began budding out of cells obtained from the choroid plexus. After an additional 3 weeks, budding was observed in kidney cell cultures and eventually in monocyte cultures as well. Serum from the lamb was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for Aspergillus, Blastomyces, Coccidioidomycosis and Histoplasmosis. DNA was isolated from fungi collected from tissue culture supernatants and used in a set of pan-fungal PCR assays with DNA from Candida acting as a positive control. PCR products were sequenced and BLAST analysis performed. The unknown fungal sequence aligned with 100% identity to Rhodotorula minuta an emerging opportunistic pathogen. Samples were submitted to The Fungal Testing Laboratory at The University of Texas Health Science Center at San Antonio for additional validation. We believe this to be the first report of Rhodotorula fungemia in a sheep in the United States.


Subject(s)
Fungemia/microbiology , Rhodotorula/isolation & purification , Sheep Diseases/microbiology , Animals , Antifungal Agents , Colorado , Polymerase Chain Reaction , Sheep
2.
J Anim Sci ; 91(11): 5114-21, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23989875

ABSTRACT

Small ruminant lentiviruses (SRLV) adversely affect production and well-being of sheep and goats throughout much of the world. The SRLV, including ovine progressive pneumonia virus (OPPV) in North America, cause lifetime infections, and management procedures to eradicate or reduce disease prevalence are costly. Variants of ovine transmembrane protein 154 gene (TMEM154) affect susceptibility to OPPV. The primary experimental objective was to estimate additive and dominance effects of TMEM154 haplotypes 1 and 3 on susceptibility to OPPV infection following natural exposure. A group of 187 trial lambs was born and raised by mature, infected ewes to ensure natural exposure to OPPV. Parents of trial lambs were heterozygous for haplotypes 1 and 3, producing lambs with diplotypes "1 1," "1 3," and "3 3." A group of 20 sentinel lambs was born and raised by mature, uninfected ewes that were diplotype "1 1." Sentinel lambs had diplotypes "1 1" and "1 3," being sired by the same set of rams as trial lambs. Trial and sentinel lambs were comingled during the experiment. Lambs were weaned at 60 d of age, bled 1 wk after weaning, and thereafter at intervals of 4 or 5 wk until 9 mo of age when OPPV infection status was determined by use of a competitive enzyme-linked immunosorbent assay. Only 1 sentinel lamb became infected. Infection status of trial lambs was analyzed using logistic regression procedures to account for the binary nature of infection status and random effects of sires. Effects of sex, type of birth, type of rearing, age of dam, breed type of dam, and sires were not detected (P>0.20). Infection status was affected by diplotype of lamb (P=0.005), with additive (P=0.002) and dominance (P=0.052) effects identified. Predicted probabilities of infection for lambs with diplotypes "1 1," "1 3," and "3 3" were 0.094, 0.323, and 0.346, respectively. Confidence intervals for probabilities of infection for diplotypes "1 3" and "3 3" were similar, but distinct from diplotype "1 1." These results are consistent with complete dominance of haplotype 3 relative to haplotype 1. The probability of infection at 9 mo of age for lambs with either diplotype "1 3" or "3 3" averaged 3.56 times that of lambs with diplotype "1 1." Genetic susceptibility to OPPV infection can be reduced by selection to increase the frequency of haplotype 1, resulting in a greater proportion of lambs with diplotype "1 1."


Subject(s)
Genetic Predisposition to Disease , Genetic Testing , Haplotypes , Lentivirus Infections/veterinary , Lentivirus/classification , Sheep Diseases/virology , Animals , Female , Lentivirus Infections/genetics , Lentivirus Infections/virology , Male , Sheep , Sheep Diseases/genetics
3.
J Virol ; 82(20): 10318-20, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18632863

ABSTRACT

Variation in the ovine prion protein amino acid sequence influences scrapie progression, with sheep homozygous for A(136)R(154)Q(171) considered susceptible. This study examined the association of survival time of scrapie-exposed ARQ sheep with variation elsewhere in the ovine prion gene. Four single nucleotide polymorphism alleles were associated with prolonged survival. One nonsynonymous allele (T112) was associated with an additional 687 days of survival for scrapie-exposed sheep compared to M112 sheep (odds ratio, 42.5; P = 0.00014). The only two sheep homozygous for T112 (TARQ) did not develop scrapie, suggesting that the allelic effect may be additive. These results provide evidence that TARQ sheep are genetically resistant to development of classical scrapie.


Subject(s)
Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Prions/genetics , Scrapie/genetics , Sheep Diseases/genetics , Amino Acid Sequence , Animals , Haplotypes , Humans , Prions/metabolism , Scrapie/mortality , Sheep/genetics , Sheep/metabolism , Sheep Diseases/mortality , Survival Rate
4.
Eur Respir J ; 27(3): 585-93, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16507860

ABSTRACT

Recently, granulocyte-macrophage colony-stimulating factor (GM-CSF) auto-antibodies have been found in many patients with pulmonary alveolar proteinosis (PAP). The present study reports a retrospective case series of patients who used aerosolised GM-CSF in the treatment of idiopathic PAP. Between 1999 and 2003, 12 patients elected to receive aerosolised GM-CSF (250 microg b.i.d. every other week) in lieu of whole-lung lavage or observation. Patient characteristics, pulmonary function tests, arterial blood gas analysis, laboratory values and chest radiographs were extracted from the patient's medical records. Of the six patients tested, all had GM-CSF neutralising antibodies. Additionally, abnormalities in GM-CSF gene expression (one patient), receptor expression (two patients) and ability to upregulate adhesion molecules (one patient) were found. All patients except one had a positive response (mean improvements in arterial oxygen tension, alveolar-arterial oxygen gradient, carbon monoxide diffusing capacity of the lung and forced vital capacity were 17.1 mmHg, 18.4 mmHg, 16.6% pred and 13.5% pred, respectively). Two patients made a complete recovery and were disease free 1 and 2 yrs after discontinuing treatment. Four patients showed complete response to both the initial course or when treated again for recurrence after discontinuation of treatment. One patient required dose escalation (500 microg b.i.d.) with complete response. GM-CSF was well tolerated without late toxicity after median (range) follow-up of 30.5 (3-68) months. In conclusion, aerosolised granulocyte-macrophage colony-stimulating factor is safe and effective in treating pulmonary alveolar proteinosis providing an alternative to whole-lung lavage or subcutaneous granulocyte-macrophage colony-stimulating factor.


Subject(s)
Granulocyte-Macrophage Colony-Stimulating Factor/administration & dosage , Pulmonary Alveolar Proteinosis/drug therapy , Administration, Inhalation , Adult , Female , Humans , Male , Middle Aged , Retrospective Studies
6.
Oral Microbiol Immunol ; 18(4): 249-55, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12823801

ABSTRACT

Eubacterium spp. and Streptococcus spp. are virulent, commonly identified microorganisms in endodontic infections. The purpose of this study was to use molecular methods to identify these organisms in 22 infected root canals that include eight cases with preoperative clinical symptoms and five cases with a history of diabetes mellitus. The presence of Streptococcus spp. and Eubacterium spp. was examined using two sets of PCR primers specific with multiple species within the respective genera. Positive specimens had their PCR products sequenced and phylogenetically analyzed to identify the specific species. Sixteen specimens (73%) contained Eubacterium spp. and nine (41%) were positive for Streptococcus spp. Eubacterium infirmum was the most prevalent Eubacterium sp. This organism was significantly associated with a history of diabetes (OR = 9.6; P = 0.04). Streptococcus anginosus was the most common Streptococcus sp., but neither it nor any of the other streptococci were significantly associated with the clinical parameters evaluated.


Subject(s)
Dental Pulp Necrosis/microbiology , Eubacterium/genetics , Periapical Periodontitis/microbiology , Streptococcus/genetics , Bacterial Typing Techniques , Chi-Square Distribution , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Diabetes Mellitus/microbiology , Eubacterium/isolation & purification , Humans , Odds Ratio , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA , Streptococcus/isolation & purification
7.
J Exp Med ; 193(9): 1015-26, 2001 May 07.
Article in English | MEDLINE | ID: mdl-11342586

ABSTRACT

The finding that Treponema pallidum, the syphilis spirochete, contains 12 orthologs of the Treponema denticola outer membrane major sheath protein has engendered speculation that members of this T. pallidum repeat (Tpr) family may be similarly surface exposed. In this regard, the TprK protein was reported to be a target of opsonic antibody and protective immunity and subject to immunologically driven sequence variation. Despite these findings, results from our previous analyses of treponemal outer membranes in concert with computer-based predictions for TprK prompted us to examine the cellular location of this protein. TprK-alkaline phosphatase fusions expressed in Escherichia coli demonstrate that TprK contains a signal peptide. However, opsonophagocytosis assays failed to indicate surface exposure of TprK. Moreover, results from three independent methodologies, i.e., (a) indirect immunofluorescence analysis of agarose-encapsulated organisms, (b) proteinase K treatment of intact spirochetes, and (c) Triton X-114 phase partitioning of T. pallidum conclusively demonstrated that native TprK is entirely periplasmic. Consistent with this location, immunization with the recombinant protein failed to induce either protective immunity or select for TprK variants in the rabbit model of experimental syphilis. These findings challenge the notion that TprK will be a component of an efficacious syphilis vaccine.


Subject(s)
Antibodies, Bacterial/immunology , Bacterial Outer Membrane Proteins/immunology , Periplasm/metabolism , Treponema pallidum/immunology , Amino Acid Sequence , Animals , Bacterial Outer Membrane Proteins/genetics , Bacterial Outer Membrane Proteins/metabolism , Base Sequence , Cell Membrane/metabolism , Codon, Initiator , DNA, Bacterial , Endopeptidase K/metabolism , Genes, Bacterial , Genetic Variation , Molecular Sequence Data , Protein Biosynthesis , Rabbits , Sequence Homology, Amino Acid , Syphilis/prevention & control , Transcription, Genetic , Treponema pallidum/genetics , Vaccination
8.
J Transcult Nurs ; 12(4): 275-83, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11989218

ABSTRACT

To be effective, HIV/AIDS interventions must be culturally and linguistically appropriate and must occur within the context of the specific community in which they are delivered. In this article, the development of a culture-specific lay health advisor (LHA) program, Protegiendo Nuestra Comunidad, for recently immigrated Mexicans is described. This program is one component of a collaborative inquiry research project involving community participants and researchers working as partners in carrying out and assessing a program for the prevention of HIV/AIDS. The collaborative inquiry process was applied as an empowerment philosophy and methodology of Paulo Freire and an ecological framework was used for the development of Protegiendo Nuestra Comunidad. The use of principles of empowerment for curriculum development, teaching methodology, and program delivery are described.


Subject(s)
Community Participation , HIV Infections/ethnology , HIV Infections/prevention & control , Health Education , Mexican Americans/education , Humans
9.
Infect Immun ; 68(3): 1574-86, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10678977

ABSTRACT

In this study, we characterized seven members of the cp32/18 family of supercoiled plasmids in Borrelia burgdorferi 297. Complete sequence analysis of a 21-kb plasmid (cp18-2) confirmed that the strain 297 plasmids are similar in overall content and organization to their B31 counterparts. Of the 31 open reading frames (ORFs) in cp18-2, only three showed sequence relatedness to proteins with known functions, and only one, a ParA/SopA ortholog, was related to nonborrelial polypeptides. Besides the lipoproteins, none of the ORFs appeared likely to encode a surface-exposed protein. Comparison with the B31 genomic sequence indicated that paralogs for most of the ORFs in cp18-2 can be identified on other genetic elements. cp18-2 was found to lack a 9- to 10-kb fragment present in the 32-kb homologs which, by extrapolation from the B31 cp32 sequences, contains at least 15 genes presumed to be unnecessary for plasmid maintenance. Sequence analysis of the lipoprotein-encoding variable loci provided evidence that recombinatorial processes within these regions may result in the acquisition of exogenous DNA. Pairwise analysis with random shuffling revealed that the multiple lipoproteins (Mlp; formerly designated 2.9 LPs) fall into two distinct homology groups which appear to have arisen by gene fusion events similar to those recently proposed to have generated the three OspE, OspF, and Elp lipoprotein families (D. R. Akins, M. J. Caimano, X. Yang, F. Cerna, M. V. Norgard, and J. D. Radolf, Infect. Immun. 67:1526-1532, 1999). Comparative analysis of the variable regions also indicated that recombination within the loci of each plasmid may occur independently. Last, comparison of variable loci revealed that the cp32/18 plasmid complements of the B31 and 297 isolates differ substantially, indicating that the two strains have been subject to divergent adaptive pressures. In addition to providing evidence for two different types of recombinatorial events involving cp32/18 plasmids, these findings underscore the need for genetic analysis of diverse borrelial isolates in order to elucidate the Lyme disease spirochete's complex parasitic strategies.


Subject(s)
Borrelia burgdorferi Group/genetics , Plasmids , Amino Acid Sequence , Biological Evolution , Chromosome Mapping , Gene Deletion , Molecular Sequence Data , Open Reading Frames , Repetitive Sequences, Nucleic Acid
10.
Appl Environ Microbiol ; 65(10): 4521-7, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10508084

ABSTRACT

Actinorhizal plants invade nitrogen-poor soils because of their ability to form root nodule symbioses with N(2)-fixing actinomycetes known as Frankia. Frankia strains are difficult to isolate, so the diversity of strains inhabiting nodules in nature is not known. To address this problem, we have used the variability in bacterial 16S rRNA gene sequences amplified from root nodules as a means to estimate molecular diversity. Nodules were collected from 96 sites primarily in northeastern North America; each site contained one of three species of the family Myricaceae. Plants in this family are considered to be promiscuous hosts because several species are effectively nodulated by most isolated strains of Frankia in the greenhouse. We found that strain evenness varies greatly between the plant species so that estimating total strain richness of Frankia within myricaceous nodules with the sample size used was problematical. Nevertheless, Myrica pensylvanica, the common bayberry, was found to have sufficient diversity to serve as a reservoir host for Frankia strains that infect plants from other actinorhizal families. Myrica gale, sweet gale, yielded a few dominant sequences, indicating either symbiont specialization or niche selection of particular ecotypes. Strains in Comptonia peregrina nodules had an intermediate level of diversity and were all from a single major group of Frankia.


Subject(s)
Actinomycetales/classification , Plants/microbiology , Actinomycetales/isolation & purification , DNA, Ribosomal/chemistry , RNA, Ribosomal, 16S/genetics , Reproducibility of Results
11.
Clin Cancer Res ; 5(9): 2316-23, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10499599

ABSTRACT

The objective was to study the feasibility of granulocyte macrophage-colony stimulating factor (GM-CSF) delivery to the lung using an aerosol in humans. A Phase I dose escalation study provided GM-CSF at three dose levels as a twice-a-day (BID) x 7 days schedule. Pulmonary functions were monitored using a remote spirometry device. Blood counts were checked at the beginning and end of each week of GM-CSF nebulization. If no toxicity was encountered, patients rested for 7 days and then were treated at the next dose level. Six of seven patients were successfully dose escalated from 60 microg/dose BID x 7 days, to 120 microg/dose BID x 7 days, then 240 microg/dose BID x 7 days. No toxicity was seen. Comparison of day 0 and day 7 blood leukocyte counts showed no significant increases in either leukocyte numbers or percentage of neutrophils. Pulmonary functions test changes were minor. No significant change in forced vital capacity, FEV1, peak flow, or FEF 25-75 related to either time or dose level was observed. One patient's lung metastases progressed. The other five patients received an additional 2-6 months of intermittent aerosol GM-CSF at dose level 3 without side effects. One patient with Ewing's sarcoma has a complete response, and a patient with melanoma had a partial response; the other three had stabilization of pulmonary metastases for 2-6 months. Aerosol delivery of GM-CSF is feasible, safe, and possibly effective. Aerosol cytokine delivery may achieve effective immunological activation against cancer in the lung and is worthy of further study.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Granulocyte-Macrophage Colony-Stimulating Factor/administration & dosage , Granulocyte-Macrophage Colony-Stimulating Factor/adverse effects , Lung Neoplasms/drug therapy , Lung Neoplasms/secondary , Administration, Inhalation , Adult , Aerosols , Aged , Antineoplastic Agents/therapeutic use , Blood Cell Count/drug effects , Dose-Response Relationship, Drug , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Humans , Lung Neoplasms/physiopathology , Middle Aged , Respiratory Function Tests
12.
Appl Environ Microbiol ; 65(8): 3328-34, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10427015

ABSTRACT

A pure culture of an obligately anaerobic marine bacterium was obtained from an anaerobic enrichment culture in which taurine (2-aminoethanesulfonate) was the sole source of carbon, energy, and nitrogen. Taurine fermentation resulted in acetate, ammonia, and sulfide as end products. Other sulfonates, including 2-hydroxyethanesulfonate (isethionate) and cysteate (alanine-3-sulfonate), were not fermented. When malate was the sole source of carbon and energy, the bacterium reduced sulfate, sulfite, thiosulfate, or nitrate (reduced to ammonia) but did not use fumarate or dimethyl sulfoxide as a terminal electron acceptor for growth. Taurine-grown cells had significantly lower adenylylphosphosulfate reductase activities than sulfate-grown cells had, which was consistent with the notion that sulfate was not released as a result of oxidative C-S bond cleavage and then assimilated. The name Desulforhopalus singaporensis is proposed for this sulfate-reducing bacterium, which is morphologically unusual compared to the previously described sulfate-reducing bacteria by virtue of the spinae present on the rod-shaped, gram-negative, nonmotile cells; endospore formation was not discerned, nor was desulfoviridin detected. Granules of poly-beta-hydroxybutyrate were abundant in taurine-grown cells. This organism shares with the other member of the genus Desulforhopalus which has been described a unique 13-base deletion in the 16S ribosomal DNA. It differs in several ways from a recently described endospore-forming anaerobe (K. Denger, H. Laue, and A. M. Cook, Arch. Microbiol. 168:297-301, 1997) that reportedly produces thiosulfate but not sulfide from taurine fermentation. D. singaporensis thus appears to be the first example of an organism which exhibits sulfidogenesis during taurine fermentation. Implications for sulfonate sulfur in the sulfur cycle are discussed.


Subject(s)
Bacteria/metabolism , Sulfides/metabolism , Taurine/metabolism , Bacteria/genetics , Bacteria/ultrastructure , Fermentation , Inclusion Bodies/metabolism , Inclusion Bodies/ultrastructure , Microscopy, Electron, Scanning , Molecular Sequence Data , Oxidation-Reduction , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sulfates/metabolism , Terminology as Topic
14.
Appl Environ Microbiol ; 62(8): 2904-9, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8702283

ABSTRACT

To study the global diversity of plant-symbiotic nitrogen-fixing Frankia strains, a rapid method was used to isolate DNA from these actinomycetes in root nodules. The procedure used involved dissecting the symbiont from nodule lobes; ascorbic acid was used to maintain plant phenolic compounds in the reduced state. Genes for the small-subunit rRNA (16S ribosomal DNA) were amplified by the PCR, and the amplicons were cycle sequenced. Less than 1 mg (fresh weight) of nodule tissue and fewer than 10 vesicle clusters could serve as the starting material for template preparation. Partial sequences were obtained from symbionts residing in nodules from Ceanothus griseus, Coriaria arborea, Coriaria plumosa, Discaria toumatou, and Purshia tridentata. The sequences obtained from Ceonothus griseus and P. tridentata nodules were identical to the sequence previously reported for the endophyte of Dryas drummondii. The sequences from Frankia strains in Coriaria arborea and Coriaria plumosa nodules were identical to one another and indicate a separate lineage for these strains. The Frankia strains in Discaria toumatou nodules yielded a unique sequence that places them in a lineage close to bacteria that infect members of the Elaeagnaceae.


Subject(s)
Actinomycetales/genetics , DNA, Bacterial/analysis , Plants/microbiology , RNA, Ribosomal, 16S/genetics , Base Sequence , DNA, Bacterial/chemistry , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction
15.
Ann Otol Rhinol Laryngol ; 104(3): 203-9, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7872603

ABSTRACT

Gelatinases (GLs) belong to a family of enzymes known as matrix metalloproteinases (MMPs), which are produced by both normal and neoplastic cells. These enzymes have been implicated in tumor invasion and metastasis, although the mechanism of regulation of tumor MMP production is unknown. Since our previous studies have shown that numerous cytokines are present in the tumor microenvironment, our goal was to establish the effect of selected cytokines on GL production by both established tumor cell lines and primary cultures of head and neck squamous cell carcinoma (HNSCC). Supernatants of HNSCC cell lines SCC-25 and FADU stimulated with interleukin (IL)-1 alpha and IL-1 beta demonstrated modest induction of 92 kd GL production by zymogram analysis when compared with controls; IL-2, IL-6, and interferon-gamma had no consistent effect on MMP production. Stimulation of cell lines with tumor necrosis factor (TNF)-alpha (10(4) to 10 U/mL), however, dramatically enhanced production of 92 kd GL by both cell lines in a dose-dependent fashion, although tissue inhibitor of metalloproteinase (TIMP) expression was unaffected. Northern blot analysis showed that this enhancement of 92 kd GL occurred at the messenger RNA level. Stimulation of short-term primary tumor cultures with TNF-alpha resulted in significant enhancement of 92 kd GL expression in one of four cultures and enhancement of 72 kd GL expression in all cultures. The observed increase in GL expression by TNF-alpha suggests a role for this cytokine in the regulation of GL expression by tumor cells during invasion and metastasis.


Subject(s)
Carcinoma, Squamous Cell/enzymology , Gelatinases/biosynthesis , Head and Neck Neoplasms/enzymology , Tumor Necrosis Factor-alpha/physiology , Cytokines/physiology , Humans , Molecular Weight , Tumor Cells, Cultured
16.
Cell Growth Differ ; 4(12): 975-83, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8117624

ABSTRACT

An epidermal growth factor (EGF) responsive DNA-binding protein (ERDBP-1) has been identified. It recognizes with high affinity and specificity a specific single-stranded DNA sequence located in the S1 nuclease-sensitive site of the EGF receptor (EGFR) 5' flanking region. The EGF-responsive element, determined by footprint analysis, is located from -364 to -344 (86-106 base pairs upstream from the major in vivo transcription initiation site). The factor does not recognize the antisense DNA sequence or double-stranded DNA of the EGF-responsive element. Three bands were observed by mobility shift assay using nuclear extracts from normal human keratinocytes. UV cross-linking followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed one major band with molecular weight in the range of 121,000 to 128,000. The induction of ERDBP-1 became evident 3 to 4 h after EGF stimulation and remained elevated as long as EGF was present. HL60 cells are devoid of endogenous EGFR and produce no ERDBP-1. Retroviral gene transfer of EGFR into HL60 cells resulted in induction of ERDBP-1 by EGF to levels comparable to those found in human keratinocytes.


Subject(s)
DNA-Binding Proteins/metabolism , Epidermal Growth Factor/physiology , ErbB Receptors/genetics , Promoter Regions, Genetic , Base Sequence , Binding Sites , Cells, Cultured , Humans , Keratinocytes/metabolism , Molecular Sequence Data , Single-Strand Specific DNA and RNA Endonucleases/metabolism , Transcriptional Activation , Ultraviolet Rays
17.
Cell Growth Differ ; 4(9): 769-76, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8241025

ABSTRACT

HL60 cells are devoid of endogenous epidermal growth factor receptor (EGFR). They respond to retinoic acid and undergo terminal granulocytic differentiation. EGFR complementary DNA was introduced into HL60 cells by retroviral gene transfer. Scatchard plot showed that the binding characteristics are identical to those of A431 cells. HL60-EGFR cells were estimated to express 34,000 EGFR/cell (Kd = 5 nM). The tyrosine phosphorylation upon ligand binding is the first step of signal transduction. The dominant phosphotyrosyl proteins in epidermal growth factor-stimulated HL60-EGFR cells include a 170 kDa protein (EGFR itself), and 125 and 53 kDa proteins. The EGFR signal results in the induction of 92 kDa gelatinase/matrix metalloproteinase in HL60-EGFR cells, thereby providing evidence of the function of the exogenous EGFR and a semiquantitative measure of the EGFR signal. These HL60-EGFR cells offer a unique opportunity to examine the potentially important role of EGFR (c-erbB) in maintaining homeostasis between self-renewal and differentiation. c-erbB has been shown to play a physiological role in the self-renewal of the very early avian stem cells which do express EGFR. The v-erbB (double truncated EGFR) has been shown to cause avian erythroblastosis. We found that these HL60-EGFR cells responded to retinoic acid differently from the HL60-control cells. A partial block of only 45% granulocytic differentiation and concomitant proliferation was noted, consistent with a shift of balance between self-renewal and differentiation toward the former.


Subject(s)
ErbB Receptors/genetics , Granulocytes/drug effects , Retroviridae/genetics , Signal Transduction/genetics , Tretinoin/antagonists & inhibitors , Cell Differentiation/drug effects , Gene Transfer Techniques , Granulocytes/cytology , Humans , Tumor Cells, Cultured
18.
Biochem Biophys Res Commun ; 193(1): 167-74, 1993 May 28.
Article in English | MEDLINE | ID: mdl-8503904

ABSTRACT

Epidermal growth factor (EGF) can stimulate proliferation and 92 kDa gelatinase/matrix metalloproteinase (MMP-9) expression. The induction of MMP-9 is not only pathologically significant for invasion and metastasis, but also serves as a semiquantitative measure of EGF signal transduction. In order to examine the role of mutated ras p21 in EGF signal transduction, an activated Ha-ras-transformed human keratinocyte cell line was developed and characterized. Overexpression of the mutated Ha-ras p21 in these cells was demonstrated. Our results showed that EGF induced 92 kDa MMP-9 secretion was doubled in the ras-transformed keratinocytes in comparison to the parent cells. The karyotype, the expression of EGF receptor (EGFR) and transforming growth factor (TGF) alpha at the mRNA level remained unchanged. These results suggest that the presence of high levels of mutated ras p21 may be responsible for the aberrant EGF signal transduction and contributes to transformation. In addition, a reduction of TGF beta expression at mRNA level by 70% was found in the activated Ha-ras-transformed keratinocytes when compared to the parent cells.


Subject(s)
Epidermal Growth Factor/metabolism , Genes, ras , Keratinocytes/metabolism , Signal Transduction , Cell Line, Transformed , Collagenases/metabolism , ErbB Receptors/genetics , ErbB Receptors/metabolism , Humans , Keratinocytes/enzymology , Matrix Metalloproteinase 9 , RNA, Messenger/metabolism , Transforming Growth Factor alpha/genetics , Transforming Growth Factor alpha/metabolism
19.
Hand Clin ; 7(2): 373-81, 1991 May.
Article in English | MEDLINE | ID: mdl-1880170

ABSTRACT

Rheumatoid arthritis frequently involves the distal radioulnar joint region and is progressive. Early recognition of involvement is paramount to offering patients appropriate and timely treatment. Early operative intervention should be considered preventative. Synovectomy, hemiresection interposition technique, matched distal ulna resection and distal radioulnar fusion with creation of a pseudarthrosis through the distal ulnar shaft have been advocated for patients with early involvement. Distal ulnar resection remains the most commonly used procedure for advanced disease. No soft tissue reconstructive procedure to stabilize the ulnar stump offers distinct advantages. They should be considered modifiers and augmentations to distal ulna resection. Judicious resection of the ulnar head minimizes instability of the ulnar stump. The use of an ulnar cap is not recommended for routine use.


Subject(s)
Arthritis, Rheumatoid/surgery , Wrist Joint/surgery , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/therapy , Humans , Radius/surgery , Surgical Procedures, Operative/methods , Ulna/surgery , Wrist Joint/physiopathology
20.
Am J Med Sci ; 295(5): 453-8, 1988 May.
Article in English | MEDLINE | ID: mdl-3287918

ABSTRACT

The peritoneal dialysis system is composed of unique membranes. To better understand the contribution of these membranes to peritoneal transport, the peritoneal surface areas were measured in human subjects and rats.


Subject(s)
Peritoneum/anatomy & histology , Animals , Cadaver , Histological Techniques , Humans , Male , Organ Size , Peritoneal Dialysis , Rats , Rats, Inbred Strains , Regression Analysis , Surface Properties
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