Ellen A. Goldmuntz

Genetic map of nine polymorphic loci comprising a single linkage group on rat chromosome 10: evidence for linkage conservation with human chromosome 17 and mouse chromosome 11.

Seven genes and two anonymous markers were mapped to a single linkage group on rat chromosome 10 using progeny of an F2 intercross of Fischer (F344/N) and Lewis (LEW/N) inbred rats. Two genes, the neu oncogene or cellular homologue of the viral oncogene erbb2 (ERBB2) and growth hormone (GH) were mapped by Southern blot analysis of restriction fragment length polymorphisms. Five genes, embryonic skeletal myosin heavy chain (MYH3), androgen binding protein/sex hormone binding globulin (SHBG), asialoglycoprotein receptor (hepatic lectin)-1 (ASGR1), ATP citrate lysase (CLATP), and pancreatic polypeptide (PPY), and two anonymous markers, F16F2 and F10F1, were mapped using PCR amplification techniques. The PCR-typable polymorphic markers for the five genes were also highly polymorphic in 10 other inbred rat strains (SHR/N, WKY/N, MNR/N, MR/N, LOU/MN, BN/SsN, BUF/N, WBB1/N, WBB2/N, and ACI/N). These markers should be useful in genetic analysis of traits described in inbred rat strains, as well as in genetic monitoring of such strains. The loci in this linkage group covered 50 cM of rat chromosome 10 with the following order: MYH3, SHBG/ASGR1 (no recombinants detected), F16F2, ERBB2, CLATP, PPY, GH, and F10F1. Comparative gene mapping analysis indicated that this region of rat chromosome 10 exhibits linkage conservation with regions of human chromosome 17 and mouse chromosome 11.

Gastric Antral Vascular Ectasia and Its Clinical Correlates in Patients with Early Diffuse Systemic Sclerosis in the SCOT Trial

Objective. To describe the prevalence and clinical correlates of endoscopic gastric antral vascular ectasia (GAVE; “watermelon stomach”) in early diffuse systemic sclerosis (SSc). Methods. Subjects with early, diffuse SSc and evidence of specific internal organ involvement were considered for the Scleroderma: Cyclophosphamide Or Transplant (SCOT) trial. In the screening procedures, all patients underwent upper gastrointestinal endoscopy. Patients were then categorized into those with or without endoscopic evidence of GAVE. Demographic data, clinical disease characteristics, and autoantibody data were compared using Pearson chi-square or Student t tests. Results. Twenty-three of 103 (22.3%) individuals were found to have GAVE on endoscopy. Although not statistically significant, anti-topoisomerase I (anti-Scl70) was detected less frequently among those with GAVE (18.8% vs 44.7%; p = 0.071). Similarly, anti-RNP antibodies (anti-U1 RNP) showed a trend to a negative association with GAVE (0 vs 18.4%; p = 0.066). There was no association between anti-RNA polymerase III and GAVE. Patients with GAVE had significantly more erythema or vascular ectasias in other parts of the stomach (26.1% vs 5.0%; p = 0.003). Conclusion. Endoscopic GAVE was present on screening in almost one-fourth of these highly selected patients with early and severe diffuse SSc. While anti-Scl70 and anti-U1 RNP trended toward a negative association with GAVE, there was no correlation between anti-RNA Pol III and GAVE. Patients with GAVE had a higher frequency of other gastric vascular ectasias outside the antrum, suggesting that GAVE may represent part of the spectrum of the vasculopathy in SSc.

A simplified, competitive RT-PCR method for measuring rat IFN-γ mRNA expression

We describe an adaptation of competitive RT-PCR to quantitate rat IFN-γ mRNA expression. An IFN-γ DNA mimic that shared the same primers and had an identical sequence to the target mRNA except for deletion of 66 nucleotides, was created by a simple PCR amplification from target cDNA. To reduce variations of initial RNA concentrations, β-actin cDNAs from each target RNA sample were normalized using the densitometric data. A known amount of pretitrated DNA competitor was then used to analyze the relative levels of target cDNA in different samples by PCR co-amplification. The amplification efficiency for both target and competitor remained constant throughout the PCR reaction, and the ratio of target to competitor PCR product remained proportional to the initial ratio of target to competitor. Relative mRNA levels among samples determined by this method were comparable to levels determined by northern blot analysis. They were also comparable to levels of IFN-γ protein estimated by ELISA. We conclude that this method can be used to estimate the relative abundance of the target mRNA. This method is adaptable to quantitation of other cytokines and is particularly valuable if there are numerous samples, or if the amount of initial mRNA is limited.

Randomized, Double-Blind, Placebo-Controlled Trial of the Effect of Vitamin D3 on the Interferon Signature in Patients With Systemic Lupus Erythematosus.

Vitamin D modulates the immune response and blocks induction of an interferon (IFN) signature by systemic lupus erythematosus (SLE) sera. This study was undertaken to investigate the effects of vitamin D supplementation on the IFN signature in patients with SLE.

Linkage map of 10 polymorphic markers on rat chromosome 2

Analysis of F2 intercross progeny of inbred F344/N x LEW/N rats led to the assignment of 10 polymorphic PCR-typable markers to rat chromosome 2. The markers form a single linkage group covering 47.9 cM with the following order: D2N1R-D2N28-FGG (gamma fibrinogen)-PKLR (liver and RBC pyruvate kinase)-ATP1A1 (the alpha-1 polypeptide of Na+/K+ transporting ATPase)-HSD3B (hydroxy-delta-5-steroid dehydrogenase)-D2N2R-D2N91-CAMKI (calmodulin-dependent protein kinase II)-D2N35. All but two of the markers (D2N1R and D2N2R) were detected using specific PCR primers flanking dinucleotide repeats. Sequences with dinucleotide repeats associated with five genes (FGG, PKLR, ATP1A1, HSD3B, and CAMKI) were identified in GenBank, and primers were designed to flank these repeats. The PCR primer pairs for three anonymous markers (D2N28, D2N91, and D2N35) were identified by sequencing cloned LEW/N rat genomic DNA containing (CA)n.(GT)n repeats. D2N1R and D2N2R were identified by PCR amplification of genomic DNA with single, nonspecific 10-base oligonucleotide primers. All of the markers were codominant except for D2N1R, D2N2R, and CAMKI, which only amplified from F344/N homozygous and heterozygous rat DNA. The seven codominant markers were highly polymorphic in 10 other inbred rat strains (SHR/N, WKY/N, MNR/N, MR/N, LOU/MN, BN/SsN, BUF/N, WBB1/N, WBB2/N, and ACI/N), suggesting that they will be useful for general mapping studies among these strains. Comparative gene mapping analysis indicated that a portion of the mapped region of rat chromosome 2 exhibits synteny conservation with regions of human chromosome 1 and mouse Chromosome 3.

Genetic mapping of the athymic nude (RNU) locus in the rat to a region on Chromosome 10

The nude trait in the rat is transmitted in an autosomal recessive manner and is associated with thymic aplasia, T-cell deficiency, and hairlessness. Congenic rats homozygous for the RNU (Rowett nude) locus are important models in the study of inflammatory disease, tumor growth, and transplant rejection. The RNU locus has not been previously mapped, and the nature of the gene product is unknown. To determine the map location of this gene, a single F344.rnu/rnu (athymic nude congenic Fischer rat) male congenic rat was bred with 3 LEW/N (NIH stock Lewis rat) female rats to produce F1 progeny. Twelve F1 brother-sister breeding pairs were established. Forty-nine phenotypically nude F2 offspring (198 total) were obtained. Linkage analysis done on F2 DNA revealed highly significant cosegregation between the nude phenotype and eight polymorphic markers located on Chromosome (Chr) 10. The tightest linkages were with: MYH3 (embryonic, skeletal myosin heavy chain) and SHBG (sex hormone-binding globulin), giving 2 point lod scores of 20.2, and 20.0, respectively. The map order and map distances, determined by multipoint linkage calculations, were: RR24-(16.1 cM)-MYH3-(3.5 cM)-SHBG-(4.7 cM)-RNU-(11.9 cM)-F16F2-(24.1 cM)-CLATP (citrate lyase ATPase)-(2.4 cM)-ACE (angiotensin converting enzyme)/PPY (pancreatic polypeptide)-(14.1 cM)-RR1023. The position of the RNU locus in the rat corresponds closely with that of the recently reported nu locus in the mouse. This finding suggests that the nude phenotype in the rat and the mouse arise from defects in homologous genes.

Linkage map of seven polymorphic markers on rat chromosome 18

A genetic linkage map of seven polymorphic markers was created with F2 intercross progeny of F344/N and LEW/N rats and assigned to rat Chromosome (Chr) 18. Five of the markers described were defined by simple sequence length polymorphisms (SSLPs) associated with five genes: transthyretin (TTR), trypsin inhibitor-like protein (TILP), β2 adrenergic receptor (ADRB2), olfactory neuron-specific G protein (OLF), and gap junction protein (GJA1). One marker was defined by a restriction fragment length polymorphism (RFLP) detected with a probe for the human colony stimulating factor 1 receptor (CSF1R) gene. The D18N1R locus was defined by an anonymous DNA fragment amplified by the randomly amplified polymorphic DNA (RAPD) technique with a single short primer. These seven DNA loci formed a single genetic linkage group 30.4 cM in length with the following order: TTR-6.8 cM-D18N1R-9.1 cM-TILP-4.3 cM-CSF1R-0 cM-ADRB2-10.2 cM-OLF-0 cM-GJA1. The five SSLP markers were highly polymorphic. In a total of 13 inbred rat strains analyzed (F344/ N, LEW/N, LOU/MN, WBB1/N, WBB2/N, MR/N, MNR/N, ACI/N, SHR/N, WKY/N, BN/SsN, BUF/N, and LER/N), three to six alleles were detected for each marker. Remarkable linkage conservation was detected between the region of rat Chr 18 mapped and a region of mouse Chr 18. However, genes associated with these markers have been mapped to three different human chromosomes (Chrs 5, 6, and 18). The markers described here should be useful for genetic mapping studies and genetic monitoring of inbred rat strains.

Myeloablative Autologous Stem-Cell Transplantation for Severe Scleroderma

BACKGROUND Despite current therapies, diffuse cutaneous systemic sclerosis (scleroderma) often has a devastating outcome. We compared myeloablative CD34+ selected autologous hematopoietic stem‐cell transplantation with immunosuppression by means of 12 monthly infusions of cyclophosphamide in patients with scleroderma. METHODS We randomly assigned adults (18 to 69 years of age) with severe scleroderma to undergo myeloablative autologous stem‐cell transplantation (36 participants) or to receive cyclophosphamide (39 participants). The primary end point was a global rank composite score comparing participants with each other on the basis of a hierarchy of disease features assessed at 54 months: death, event‐free survival (survival without respiratory, renal, or cardiac failure), forced vital capacity, the score on the Disability Index of the Health Assessment Questionnaire, and the modified Rodnan skin score. RESULTS In the intention‐to‐treat population, global rank composite scores at 54 months showed the superiority of transplantation (67% of 1404 pairwise comparisons favored transplantation and 33% favored cyclophosphamide, P=0.01). In the per‐protocol population (participants who received a transplant or completed ≥9 doses of cyclophosphamide), the rate of event‐free survival at 54 months was 79% in the transplantation group and 50% in the cyclophosphamide group (P=0.02). At 72 months, Kaplan–Meier estimates of event‐free survival (74% vs. 47%) and overall survival (86% vs. 51%) also favored transplantation (P=0.03 and 0.02, respectively). A total of 9% of the participants in the transplantation group had initiated disease‐modifying antirheumatic drugs (DMARDs) by 54 months, as compared with 44% of those in the cyclophosphamide group (P=0.001). Treatment‐related mortality in the transplantation group was 3% at 54 months and 6% at 72 months, as compared with 0% in the cyclophosphamide group. CONCLUSIONS Myeloablative autologous hematopoietic stem‐cell transplantation achieved long‐term benefits in patients with scleroderma, including improved event‐free and overall survival, at a cost of increased expected toxicity. Rates of treatment‐related death and post‐transplantation use of DMARDs were lower than those in previous reports of nonmyeloablative transplantation. (Funded by the National Institute of Allergy and Infectious Diseases and the National Institutes of Health; ClinicalTrials.gov number, NCT00114530.)

Ten polymorphic DNA loci, including five in the rat MHC (RT1) region, form a single linkage group on rat chromosome 20.

We have described ten markers for polymorphic loci on rat chromosome 20, including five in the rat MHC (RT1) region. These markers formed a single linkage group spanning a recombination distance of 0.40. The markers identified five expressed gene loci - RT1.N1 (thymus leukemia antigen 1), Tnfa (tumor necrosis factor {alpha}), Hspa1 (heat shock protein 70), Ggt1 ({gamma} glutamyl-transferase 1), and Prkacn2 (protein kinase C catalytic subunit binding inhibitor 2), two loci with sequences that are related to expressed genes - RT1.Aw2 (sequence related to a non-RT1A class I {alpha} chain) and Mt21 (sequence related to metallothionein 2), and three anonymous loci - D20Arb548, D20Arb234, and D20Arb249. These polymorphic markers should facilitate mapping studies and genetic monitoring of inbred rat strains. 18 refs., 2 figs., 3 tabs.

Map of seven polymorphic markers on rat Chromosome 14: linkage conservation with human Chromosome 4

Seven polymorphic markers identified by polymerase chain reaction (PCR) amplification, including markers for six genes—DRD1L (dopamine receptor, D1-like-2), GLUKA (glucokinase), PF4 (platelet factor 4), ALB (albumin), AFP (α-fetoprotein), and BSP (bone sialoprotein)—and one anonymous locus (D14N52), were mapped to a single 67-cM linkage group with F2 intercross progeny of F344/N and LEW/N inbred rat strains. Two of these markers, ALB and AFP, have previously been assigned to rat Chromosome (Chr) 14, allowing assignment of this entire linkage group. Five of the markers—DRD1L, PF4, ALB, AFP, and PBSP—have been physically mapped to a large region of human Chr 4 encompassing the p arm and the q arm to band q28. Homologs of two of the markers, ALB and AFP, have been mapped to Chr 5 in the mouse. Comparison of human Chr 4 with the homologous regions on Chr 14 of the rat and Chr 5 of the mouse indicated that linkage conservation with human Chr 4 extends over a greater region in the rat than in the mouse. The markers described here were found to be highly polymorphic in twelve inbred strains (F344/N, LEW/N, ACI/N, BUF/N, BN/SsN, LOU/MN, MNR/N, MR/N, SHR/N, WBB1/N, WBB2/N, and WKY/N). These polymorphic markers should be useful in genetic linkage studies of important phenotypes in rats.