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2.
Lupus ; 21(1): 3-12, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21976401

ABSTRACT

African-American recipients of kidney transplants with lupus have high allograft failure risk. We studied their risk adjusting for: (1) socio-demographic factors: donor age, gender and race-ethnicity; recipient age, gender, education and insurance; donor-recipient race-ethnicity match; (2) immunologic factors: donor type, panel reactive antibodies, HLA mismatch, ABO blood type compatibility, pre-transplant dialysis, cytomegalovirus risk and delayed graft function (DGF); (3) rejection and recurrent lupus nephritis (RLN). Two thousand four hundred and six African-, 1132 Hispanic-, and 2878 Caucasian-Americans were followed for 12 years after transplantation. African- versus Hispanic- and Caucasian-Americans received more kidneys from deceased donors (71.6%, 57.3% and 55.1%) with higher two HLA loci mismatches for HLA-A (50%, 39.6% and 32.4%), HLA-B (52%, 42.8% and 35.6%) and HLA-DR (30%, 24.5% and 21.1%). They developed more DGF (19.5%, 13.6% and 13.4%). More African- versus Hispanic- and Caucasian-Americans developed rejection (41.7%, 27.6% and 35.9%) and RLN (3.2, 1.8 and 1.8%). 852 African-, 265 Hispanic-, and 747 Caucasian-Americans had allograft failure (p < 0.0001). After adjusting for transplant era, socio-demographic-immunologic differences, rejection and RLN, the increased hazard ratio for allograft failure of African- compared with Caucasian-Americans became non-significant (1.26 [95% confidence interval 0.78-2.04]). African-Americans with lupus have high prevalence of risk factors for allograft failure that can explain poor outcomes.


Subject(s)
Black or African American , Graft Rejection/immunology , Hispanic or Latino , Kidney Transplantation/immunology , White People , Adult , Ethnicity , Female , Graft Survival/immunology , Humans , Middle Aged , Risk Factors , Transplantation, Homologous/immunology , Treatment Outcome , Young Adult
3.
J Exp Med ; 166(1): 253-8, 1987 Jul 01.
Article in English | MEDLINE | ID: mdl-2439635

ABSTRACT

The acute-phase response to inflammatory stimuli, characterized by increased synthesis of acute-phase proteins (APP), is often accompanied by changes in the glycosylation patterns of some of these proteins. While expression of APP genes in hepatocytes is regulated by monokines, mechanisms governing changes in glycosylation are not known. Exposure of human hepatoma cell line Hep 3B to conditioned medium from LPS-activated human monocytes and to medium from the keratocarcinoma cell line COLO-16 led to increased synthesis of alpha 1 proteinase-inhibitor and ceruloplasmin and to alterations of their glycosylation patterns similar to those seen in human serum in various inflammatory states. IL-1, tumor necrosis factor, and hepatocyte stimulating factor I increased synthesis of ceruloplasmin without alterations in the pattern of its glycosylation. These findings demonstrate that altered glycosylation seen in plasma in some inflammatory states can be explained by the effects of monokines on glycosylation in hepatocytes and that gene expression and glycosylation of some APP during the acute-phase response may be regulated by different mechanisms.


Subject(s)
Acute-Phase Proteins/metabolism , Proteins/physiology , Blood Proteins/metabolism , Carcinoma, Hepatocellular/metabolism , Cell Line , Ceruloplasmin/metabolism , Culture Media , Glycosylation , Humans , Liver Neoplasms/metabolism , Monocytes/physiology , Monokines , alpha 1-Antitrypsin
4.
Phys Rev Lett ; 105(20): 203005, 2010 Nov 12.
Article in English | MEDLINE | ID: mdl-21231229

ABSTRACT

We demonstrate the creation of vortices in the electronic probability density of an atom subject to short electric field pulses, how these vortices evolve and can be manipulated by varying the applied pulses, and that they persist to macroscopic distances in the spectrum of ejected electrons. This opens the possibility to use practical femtosecond or shorter laser pulses to create and manipulate these vortex quasiparticles at the atomic scale and observe them in the laboratory. Within a hydrodynamic interpretation we also show, since the Schrödinger equation is a particular instance of the Navier-Stokes equations, that for compressible fluids vortices can appear spontaneously and with a certain time delay, which is not expected to occur from the conventional point of view, illustrating applicability of the present study to vortex formation more broadly.

5.
Lupus ; 19(5): 557-74, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20089610

ABSTRACT

Systemic lupus erythematosus may present with renal manifestations that frequently are difficult to categorize and lupus nephritis is an important predictor of poor outcome. The type and spectrum of renal injury may remain undiagnosed until full-blown nephritic and/or nephrotic syndrome appear with increased risk of end-stage renal disease. These abnormalities occur within the first few years after the diagnosis of lupus is made on clinical grounds and with the support of laboratory tests in high risk patients. An early renal biopsy is helpful in patients with an abnormal urinalysis and/or reduced glomerular filtration rate and the results form the basis for therapeutic decisions. The biopsy also provides vital prognostic information based on histological categorization of different types of lupus nephritis, the degree of activity, chronicity and the immunopathogenesis. In the current armamentarium, the use of cyclophosphamide and azathioprine and recently mycophenolate mofetil, reduce morbidity and maintenance therapies reduce the risk of end-stage renal disease. Clinical trials underway promise new, effective and safe immunosuppressive regimens for the treatment of proliferative lupus nephritis.


Subject(s)
Lupus Nephritis , Humans , Lupus Nephritis/classification , Lupus Nephritis/drug therapy , Lupus Nephritis/epidemiology , Lupus Nephritis/etiology , Lupus Nephritis/pathology , Practice Guidelines as Topic , Prognosis
6.
Science ; 214(4520): 557-8, 1981 Oct 30.
Article in English | MEDLINE | ID: mdl-6270789

ABSTRACT

Receptors for the activated third component of complement and for the Fc portion of immunoglobulin G are not expressed by apparently normal bovine pulmonary endothelial cells, but are expressed when the cells are exposed to white cell lysates or are infected with influenza or cytomegalovirus. The unmasking of these latent receptors may contribute to the pulmonary inflammatory response characteristic of, for example, anaphylaxis and to those lung diseases characterized by the deposition of immune complexes.


Subject(s)
Pulmonary Artery/cytology , Receptors, Complement/metabolism , Receptors, Fc/metabolism , Animals , Cattle , Cells, Cultured , Complement C3b/metabolism , Cytomegalovirus Infections/physiopathology , Endothelium/metabolism , Orthomyxoviridae Infections/physiopathology
7.
Science ; 208(4445): 748-9, 1980 May 16.
Article in English | MEDLINE | ID: mdl-7367890

ABSTRACT

Bovine pulmonary endothelial cells do not possess receptors for the 3b component of complement (C3b) or for the Fc portion of immunoglobulin G. The lack of these receptors may help explain the nonthrombogenic function of endothelial cells. Our findings rule out the possibility that endothelial cells participate in pulmonary immune complex disease through the binding of C3b or Fc fragments.


Subject(s)
Pulmonary Artery/immunology , Receptors, Complement/metabolism , Receptors, Fc/metabolism , Animals , Cattle , Cells, Cultured , Complement C3b/metabolism , Endothelium/immunology , Pulmonary Artery/metabolism , Rosette Formation
8.
Science ; 206(4418): 515-27, 1979 Nov 02.
Article in English | MEDLINE | ID: mdl-17759411

ABSTRACT

The first broad program of scientific shallow drilling on the U.S. Atlantic continental shelf has delineated rocks of Pleistocene to Late Cretaceous age, including phosphoritic Miocene strata, widespread Eocene carbonate deposits that serve as reflective seismic markers, and several regional unconformities. Two sites, off Maryland and New Jersey, showed light hydrocarbon gases having affinity to mature petroleum. Pore fluid studies showed that relatively fresh to brackish water occurs beneath much of the Atlantic continental shelf, whereas increases in salinity off Georgla and beneath the Florida-Hatteras slope suggest buried evaporitic strata. The sediment cores showed engineering properties that range from good foundation strength to a potential for severe loss of strength through interaction between sediments and man-made structures.

9.
Aust Vet J ; 86(3): 106-9, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18304049

ABSTRACT

OBJECTIVE: To determine the effect of a single intravenous (IV) fluid bolus on the hydration of an avian patient, using packed cell volume (PCV) and plasma total solids (TS) to estimate hydration. PROCEDURE: Ten birds were allocated randomly to one of three groups, and administered 30 mL/kg or 50 mL/kg intravenous fluid, or were part of a control group and did not receive IV fluid. Blood was collected before the IV fluid bolus was administered, and at 1 minute, 3 hours and 6 hours after administration of the fluid. Samples were used to determine PCV and TS and results were compared between groups and between the different time points. RESULTS: Administration of 30 mL/kg or 50 mL/kg compound sodium lactate solution caused a statistically significant decrease in PCV. Within 3 hours, the PCV was not significantly different to the initial value or to the PCV of control birds. Administration of 30 mL/kg compound sodium lactate solution did not result in a significant decrease in TS. However, administration of 50 mL/kg produced a significant decrease in TS, which was still significantly less than controls 6 hours after the fluid was administered. CONCLUSION: These findings suggest that an intravenous bolus of fluid may be safely administered to an anaemic bird, since PCV is significantly decreased for less than 3 hours. Up to 50 mL/kg of fluid may be administered as an intravenous bolus to a bird, to produce significant haemodilution that persists for up to 6 hours.


Subject(s)
Bird Diseases/therapy , Dehydration/veterinary , Fluid Therapy/veterinary , Hematocrit/veterinary , Parrots , Anemia/therapy , Anemia/veterinary , Animals , Bird Diseases/blood , Dehydration/therapy , Dose-Response Relationship, Drug , Fluid Therapy/methods , Injections, Intravenous/veterinary , Parrots/blood , Random Allocation , Treatment Outcome
10.
J Parasitol ; 104(1): 31-38, 2018 02.
Article in English | MEDLINE | ID: mdl-29119858

ABSTRACT

A novel coccidian species was discovered in the prostate of an Antechinus flavipes (yellow-footed antechinus) in South Australia during the period of postmating male antechinus immunosuppression and mortality. This novel coccidian is unusual because it develops extraintestinally and sporulates endogenously within the prostate gland of its mammalian host. Histological examination of prostatic tissue revealed dense aggregations of spherical and thin-walled tetrasporocystic, dizoic, sporulated coccidian oocysts within tubular lumina, with unsporulated oocysts and gamogonic stages within the cytoplasm of glandular epithelial cells. This coccidian was observed occurring concurrently with dasyurid gammaherpesvirus 1 infection of the antechinus' prostate. Eimeria-specific 18S small-subunit ribosomal (r)DNA polymerase chain reaction amplification was used to obtain a partial 18S rDNA nucleotide sequence from the antechinus coccidian. Bayesian phylogenetic analysis based on 18S rDNA gene sequences revealed that the novel coccidian clusters with reptile-host coccidians, forming an ancestral basal lineage of the eimeriid clade. The species has been named Eimeria taggarti n. sp. on the basis of both sporulated oocyst morphology and molecular characterization. It is suspected that E. taggarti is sexually transmitted via excretion of sporulated oocysts or free sporocysts with prostatic secretions in semen.


Subject(s)
Coccidiosis/veterinary , Eimeria/isolation & purification , Marsupialia/parasitology , Prostate/parasitology , Prostatic Diseases/veterinary , Animals , Base Sequence , Coccidiosis/parasitology , DNA, Protozoan/chemistry , DNA, Protozoan/isolation & purification , DNA, Ribosomal/chemistry , DNA, Ribosomal/isolation & purification , Eimeria/classification , Eimeria/genetics , Eimeria/ultrastructure , Immune Tolerance , Male , Marsupialia/immunology , Microscopy, Electron, Transmission/veterinary , Oocysts/growth & development , Oocysts/ultrastructure , Phylogeny , Prostatic Diseases/parasitology , RNA, Protozoan/genetics , RNA, Ribosomal, 18S/genetics , Sequence Alignment/veterinary , South Australia
11.
Mol Cell Biol ; 19(6): 4366-78, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10330177

ABSTRACT

Krüppel-associated box (KRAB) domains are present in approximately one-third of all human zinc finger proteins (ZFPs) and are potent transcriptional repression modules. We have previously cloned a corepressor for the KRAB domain, KAP-1, which is required for KRAB-mediated repression in vivo. To characterize the repression mechanism utilized by KAP-1, we have analyzed the ability of KAP-1 to interact with murine (M31 and M32) and human (HP1alpha and HP1gamma) homologues of the HP1 protein family, a class of nonhistone heterochromatin-associated proteins with a well-established epigenetic gene silencing function in Drosophila. In vitro studies confirmed that KAP-1 is capable of directly interacting with M31 and hHP1alpha, which are normally found in centromeric heterochromatin, as well as M32 and hHP1gamma, both of which are found in euchromatin. Mapping of the region in KAP-1 required for HP1 interaction showed that amino acid substitutions which abolish HP1 binding in vitro reduce KAP-1 mediated repression in vivo. We observed colocalization of KAP-1 with M31 and M32 in interphase nuclei, lending support to the biochemical evidence that M31 and M32 directly interact with KAP-1. The colocalization of KAP-1 with M31 is sometimes found in subnuclear territories of potential pericentromeric heterochromatin, whereas colocalization of KAP-1 and M32 occurs in punctate euchromatic domains throughout the nucleus. This work suggests a mechanism for the recruitment of HP1-like gene products by the KRAB-ZFP-KAP-1 complex to specific loci within the genome through formation of heterochromatin-like complexes that silence gene activity. We speculate that gene-specific repression may be a consequence of the formation of such complexes, ultimately leading to silenced genes in newly formed heterochromatic chromosomal environments.


Subject(s)
Chromosomal Proteins, Non-Histone/physiology , DNA-Binding Proteins/physiology , Heterochromatin , Nuclear Proteins , Repressor Proteins/physiology , Transcription Factors , Zinc Fingers/physiology , 3T3 Cells , Animals , Blotting, Western , COS Cells , Cell Nucleus/metabolism , Chromatin/metabolism , Chromatography, Liquid , Chromobox Protein Homolog 5 , Chromosomal Proteins, Non-Histone/metabolism , Electrophoresis, Polyacrylamide Gel , Euchromatin , Fluorescent Antibody Technique, Indirect , Luciferases/metabolism , Mice , Models, Biological , Models, Genetic , Mutagenesis , Protein Binding , Protein Conformation , Recombinant Fusion Proteins , Repressor Proteins/metabolism , Transfection , Tripartite Motif-Containing Protein 28
12.
Stud Health Technol Inform ; 245: 10-14, 2017.
Article in English | MEDLINE | ID: mdl-29295042

ABSTRACT

Smartphones that collect user geolocation provid opportunities for mobile Health (mHealth). Although granularity of geolocation data may be high, data completeness depends on the device's operating system, application developer decisions, and user actions. We investigate completeness of geolocation data collected via smartphones of 5601 people that self-reported daily chronic pain symptoms on 349,293 days. On 17% of these days, hourly geolocation data is reported, but days with 0 (16%), 1 (14%) and 2 (13%) geolocations are common. Android phones collect geolocation more often than iPhones (median 17 versus 2 times a day). Factors on operating system level and individual user level influence completeness of geolocation data collected with smartphones. mHealth researchers should be aware of these factors when designing their studies. The mHealth research community should devise standards for reporting geolocation data quality, analysing systematic differences in data quality between participant groups, and methods for data imputation.


Subject(s)
Data Accuracy , Smartphone , Telemedicine , Cell Phone , Humans , Mobile Applications
13.
J Natl Cancer Inst ; 81(24): 1893-904, 1989 Dec 20.
Article in English | MEDLINE | ID: mdl-2593166

ABSTRACT

We used the lesional steps in tumor progression and multivariable logistic regression to develop a prognostic model for primary, clinical stage I cutaneous melanoma. This model is 89% accurate in predicting survival. Using histologic criteria, we assigned melanomas to tumor progression steps by ascertaining their particular growth phase. These phases were the in situ and invasive radial growth phase and the vertical growth phase (the focal formation of a dermal tumor nodule or dermal tumor plaque within the radial growth phase or such dermal growth without an evident radial growth phase). After a minimum follow-up of 100.6 months and a median follow-up of 150.2 months, 122 invasive radial-growth-phase tumors were found to be without metastases. Eight-year survival among the 264 patients whose tumors had entered the vertical growth phase was 71.2%. Survival prediction in these patients was enhanced by the use of a multivariable logistic regression model. Twenty-three attributes were tested for entry into this model. Six had independently predictive prognostic information: (a) mitotic rate per square millimeter, (b) tumor-infiltrating lymphocytes, (c) tumor thickness, (d) anatomic site of primary melanoma, (e) sex of the patient, and (f) histologic regression. When mitotic rate per square millimeter, tumor-infiltrating lymphocytes, primary site, sex, and histologic regression are added to a logistic regression model containing tumor thickness alone, they are independent predictors of 8-year survival (P less than .0005).


Subject(s)
Melanoma/mortality , Female , Humans , Male , Melanoma/pathology , Models, Biological , Neoplasm Staging , Probability , Prognosis , Regression Analysis , Survival Rate , Time Factors
14.
Radiat Prot Dosimetry ; 122(1-4): 22-5, 2006.
Article in English | MEDLINE | ID: mdl-17132666

ABSTRACT

The use of heavy ion beams for microbeam studies of mammalian cell response leads to a need to better understand interaction cross sections for collisions of heavy ions with tissue constituents. For ion energies of a few MeV u(-1) or less, ions capture electrons from the media in which they travel and undergo subsequent interactions as partially 'dressed' ions. For example, 16 MeV fluorine ions have an equilibrium charge of 7(+), 32 MeV sulphur ions have an equilibrium charge of approximately 11(+), and as the ion energies decrease the equilibrium charge decreases dramatically. Data for interactions of partially dressed ions are extremely rare, making it difficult to estimate microscopic patterns of energy deposition leading to damage to cellular components. Such estimates, normally obtained by Monte Carlo track structure simulations, require a comprehensive database of differential and total ionisation cross sections as well as charge transfer cross sections. To provide information for track simulation, measurement of total ionisation cross sections have been initiated at East Carolina University using the recoil ion time-of-flight method that also yields cross sections for multiple ionisation processes and charge transfer cross sections; multiple ionisation is prevalent for heavy ion interactions. In addition, measurements of differential ionisation cross sections needed for Monte Carlo simulation of detailed event-by-event particle tracks are under way. Differential, total and multiple ionisation cross sections and electron capture and loss cross sections measured for C(+) ions with energies of 100 and 200 keV u(-1) are described.


Subject(s)
Biopolymers/chemistry , Biopolymers/radiation effects , Heavy Ions , Models, Chemical , Models, Molecular , Radiation, Ionizing , Radiometry/methods , Computer Simulation , Linear Energy Transfer , Monte Carlo Method , Radiation Dosage , Static Electricity
15.
Cancer Res ; 59(4): 905-10, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-10029083

ABSTRACT

To identify the epitope of the melanoma-associated chondroitin sulfate proteoglycan (MCSP) recognized by the monoclonal antibody (mAb) 763.74, we first expressed random DNA fragments obtained from the complete coding sequence of the MCSP core glycoproteins in phages and selected without success for binders to the murine mAb 763.74. We then used a library of random heptapeptides displayed at the surface of the filamentous M13 phage as fusion protein to the NH2-terminal portion of the minor coat protein III. After three rounds of selection on the bound mAb, several phages displaying related binding peptides were identified, yielding the consensus sequence Val-His-Leu-Asn-Tyr-Glu-His. Competitive ELISA experiments showed that this peptide can be specifically prevented from binding to mAb 763.74 by an anti-idiotypic MK2-23 mouse:human chimeric mAb and by A375 melanoma cells expressing the antigen MCSP. We screened the amino acid sequence of the MCSP molecule for a region of homology to the consensus sequence and found that the amino acid sequence Val-His-Ile-Asn-Ala-His spanning positions 289 and 294 has high homology. Synthetic linear peptides corresponding to the consensus sequence as well as to the MCSP-derived epitope inhibit the binding of mAb 763.74 to the phages displaying the consensus amino acid sequence. Finally, the biotinylated consensus peptide absorbed to streptavidin-microtiter plates can be used for the detection of mAb 763.74 in human serum. These results show clearly that the MCSP epitope defined by mAb 763.74 has been identified.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neoplasm/immunology , Chondroitin Sulfate Proteoglycans/analysis , Melanoma/immunology , Membrane Proteins/analysis , Amino Acid Sequence , Animals , Bacteriophages/genetics , Chondroitin Sulfate Proteoglycans/chemistry , Chondroitin Sulfate Proteoglycans/immunology , Enzyme-Linked Immunosorbent Assay , Epitopes , Gene Library , Humans , Membrane Proteins/chemistry , Membrane Proteins/immunology , Mice , Sequence Homology, Amino Acid , Tumor Cells, Cultured
16.
Cancer Res ; 56(15): 3409-14, 1996 Aug 01.
Article in English | MEDLINE | ID: mdl-8758903

ABSTRACT

Recent studies have identified mutations in the breast and (ovarian cancer susceptibility gene 2 (BRCA2), one which has been found in the germline of several males and one female affected with breast cancer. To establish the carrier frequency of this mutation in a large population of individuals affected with cancer, we evaluated constitutional DNA isolated from 83 individuals diagnosed with breast cancer and 93 diagnosed with ovarian cancer at any age, 42 of whom reported a family history of cancer. Using a simple allele-specific PCR-based nonradioactive method, we detected a total of eight individuals (4.5%) carrying a 1-bp deletion at nucleotide 6174 of the BRCA2 gene (6174delT). The age of disease onset in the mutant allele carriers was highly variable and typically late onset (41-72 years for breast cancer and 48-73 years for ovarian cancer). Evaluation of family histories for the eight mutant allele carriers revealed that several individuals had significant cancer histories that included, in addition to breast and/or ovarian cancer, an increased incidence of colon, esophageal, pancreatic, stomach, and hematopoietic cancers. Interestingly, seven of the eight individuals were of Ashkenazi Jewish descent. Haplotype data for the mutant allele carriers using markers spanning the region of the BRCA2 gene on chromosome 13ql2-ql3 suggest that only two of the confirmed Jewish Ashkenazi individuals share a single common ancestry, indicating several independent origins for this mutation. These data provide evidence for the presence of a specific BRCA2 mutation which has its origins in both Jewish Ashkenazi and non-Jewish populations. The observed overrepresentation of specific mutations within a subgroup of the general population may eventually help contribute to the development of inexpensive and routine tests such as the one described in our study.


Subject(s)
Breast Neoplasms, Male/genetics , Breast Neoplasms/genetics , Jews/genetics , Mutation , Neoplasm Proteins/genetics , Ovarian Neoplasms/genetics , Transcription Factors/genetics , Adult , Aged , Alleles , BRCA2 Protein , Base Sequence , DNA, Neoplasm/genetics , DNA, Neoplasm/isolation & purification , Disease Susceptibility , Family Health , Female , Genetic Testing , Haplotypes , Heterozygote , Humans , Male , Middle Aged , Molecular Sequence Data , Polymerase Chain Reaction , Risk Factors
17.
Cancer Res ; 43(4): 1921-5, 1983 Apr.
Article in English | MEDLINE | ID: mdl-6831427

ABSTRACT

The metabolic fate of a p.o. dose of 3.5 mmol 15N-labeled nitrate has been investigated in 12 healthy young adults. Samples of urine, saliva, plasma, and feces were collected over a period of 48 hr following administration of the dose. Subjects received either 60 mg of ascorbic acid, 2 g of ascorbic acid, or 2 g of sodium ascorbate per day. An average of 60% of the 15NO3- dose appeared in the urine as nitrate within 48 hr. Less than 0.1% appeared in the feces. The 15N label of nitrate was also found in the urine (3%) and feces (0.2%) in the form of ammonia or urea. The fate of the remaining 35% of the 15NO3- dose administered is unknown. No effect of ascorbic acid or sodium ascorbate on the nitrate and nitrite levels of plasma, saliva, urine, or feces was observed. A one-compartment pharmacokinetic model was used to describe the relationships between intake, plasma concentration, and urinary excretion of nitrate. The half-life of nitrate in the body was found to be approximately 5 hr, and its volume of distribution was about 30% of body weight. Daily endogenous biosynthesis of nitrate was estimated to be about 1 mmol/day.


Subject(s)
Ascorbic Acid/administration & dosage , Nitrates/metabolism , Administration, Oral , Adult , Feces/analysis , Humans , Kinetics , Male , Nitrates/administration & dosage , Nitrates/blood , Nitrogen Isotopes , Saliva/analysis
18.
Cancer Res ; 59(19): 4973-83, 1999 Oct 01.
Article in English | MEDLINE | ID: mdl-10519411

ABSTRACT

Loss of all or part of one copy of chromosome 17p is very common in ovarian and breast tumors. OVCA1 is a candidate tumor suppressor gene mapping to a highly conserved region on chromosome 17p13.3 that shows frequent loss of heterozygosity in breast and ovarian carcinomas. Western blot analysis of extracts prepared from breast and ovarian carcinomas revealed reduced expression of OVCA1 compared with extracts from normal epithelial cells from these tissues. Subcellular localization studies indicate that OVCA1 is localized to punctate bodies scattered throughout the cell but is primarily clustered around the nucleus. Attempts to create cell lines that stably expressed OVCA1 from the cytomegalovirus promoter were generally unsuccessful in a variety of different cell lines. This reduction of colony formation was quantified in the ovarian cancer cell line A2780, where it was demonstrated that cells transfected with plasmids expressing OVCA1 had a 50-60% reduction in colony number as compared with appropriate controls, and only a few of these clones expressed OVCA1, albeit at low levels. The clones that expressed exogenous OVCA1 were found to have dramatically reduced rates of proliferation. Reduced growth rates correlated with an increased proportion of the cells in the G1 fraction of the cell cycle compared with the parental cell line and decreased levels of cyclin D1. The low levels of cyclin D1 appeared to be caused by an accelerated rate of cyclin D1 degradation. Overexpression of cyclin D1 was able to override OVCA1's suppression of clonal outgrowth. These results suggest that slight alterations in the level of OVCA1, such as would occur after reduction of chromosome 17p13.13 to hemizygosity, may result in cell cycle deregulation and promote tumorigenesis.


Subject(s)
Chromosomes, Human, Pair 17 , Genes, Tumor Suppressor , Genetic Variation , Loss of Heterozygosity , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Proteins/genetics , Tumor Suppressor Proteins , Amino Acid Substitution , Cell Cycle/genetics , Cell Division , Chromosome Mapping , Female , Humans , Kinetics , Minor Histocompatibility Antigens , Plasmids , Point Mutation , Polymorphism, Single-Stranded Conformational , Proteins/chemistry , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Tumor Cells, Cultured
19.
Cancer Res ; 56(9): 1997-2002, 1996 May 01.
Article in English | MEDLINE | ID: mdl-8616839

ABSTRACT

A second tumor suppressor locus on 17p that is distinct from TP53 has been identified in brain, breast, lung, and ovarian tumors. Using allelic loss mapping and positional cloning methods, we have recently identified two novel genes, which we refer to as OVCA1 and OVCA2, that map to 17p13.3. The two genes are ubiquitously expressed and encode proteins of 443 and 227 amino acids, respectively, with no known functional motifs. Sequence comparison of OVCA1 and OVCA2 revealed extensive sequence identity and similarity to hypothetical proteins from Saccharomyces cerevisiae, Caenorhabditis elegans, and Rattus species. Northern blot analysis reveals that OVCA1 and OVCA2 mRNA were expressed in normal surface epithelial cells of the ovary, but the level of this transcript is significantly reduced or is undetectable in 92% (11/12) of the ovarian tumors and tumor cell lines analyzed. The location, high degree of amino acid conservation, and reduced expression in ovarian tumors and tumor cell lines suggest that decreased expression of these two genes contributes to ovarian tumorigenesis and should be considered candidate tumor suppressor genes.


Subject(s)
Chromosomes, Human, Pair 17 , Genes, Tumor Suppressor , Alleles , Amino Acid Sequence , Animals , Chromosome Deletion , Chromosome Mapping , Female , Genetic Markers , Humans , Molecular Sequence Data , Ovarian Neoplasms/genetics , Rats , Tumor Cells, Cultured
20.
Cancer Res ; 59(20): 5275-82, 1999 Oct 15.
Article in English | MEDLINE | ID: mdl-10537309

ABSTRACT

The evolutionarily conserved BTB/POZ domain from the promyelocytic leukemia zinc finger (PLZF) oncoprotein mediates transcriptional repression through the recruitment of corepressor proteins containing histone deacetylases in acute promyelocytic leukemia. We have determined the 2.0 A crystal structure of the BTB/POZ domain from PLZF (PLZF-BTB/POZ), and have carried out biochemical analysis of PLZF-BTB/POZ harboring site-directed mutations to probe structure-function relationships. The structure reveals a novel alpha/beta homodimeric fold in which dimer interactions occur along two surfaces of the protein subunits. The conservation of BTB/POZ domain residues at the core of the protomers and at the dimer interface implies an analogous fold and dimerization mode for BTB/POZ domains from otherwise functionally unrelated proteins. Unexpectedly, the BTB/POZ domain forms dimer-dimer interactions in the crystals, suggesting a mode for higher-order protein oligomerization for BTB/POZ-mediated transcriptional repression. Biochemical characterization of PLZF-BTB/POZ harboring mutations in conserved residues involved in protein dimerization reveals that the integrity of the dimer interface is exquisitely sensitive to mutation and that dimer formation is required for wild-type levels of transcriptional repression. Interestingly, similar mutational analysis of residues within a pronounced protein cleft along the dimer interface, which had been implicated previously for interaction with corepressors, has negligible effects on dimerization or transcriptional repression. Together, these studies form a structure-function framework for understanding BTB/POZ-mediated oligomerization and transcriptional repression properties.


Subject(s)
DNA-Binding Proteins/chemistry , Transcription Factors/chemistry , Zinc Fingers , Amino Acid Sequence , Crystallization , DNA-Binding Proteins/physiology , Dimerization , Molecular Sequence Data , Mutagenesis, Site-Directed , Structure-Activity Relationship , Transcription Factors/physiology , Transcription, Genetic
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