Biomedical subjects

W J Miller

Publications and source records attributed to W J Miller.

At least 19 recordsLinked to original sources

PubMed1998

Expression and purification of recombinant tick anticoagulant peptide (Y1W/D10R) double mutant secreted by Saccharomyces cerevisiae.

A double mutant of tick anticoagulant peptide (TAP) was cloned as a chimeric fusion with the yeast alpha-mating factor pre-proleader peptide. Expression in yeast (Saccharomyces cerevisiae) resulted in the secretion of the TAP mutein into the culture medium. An HPLC-based assay was used to screen yeast strains to find those giving highest expression levels. Efficiency of cleavage at the junction of the leader-TAP mutein varied from strain to strain, and a rapid purification method followed by N-terminal sequence analysis was used to identify a host strain that minimized undesirable cleavage products. A purification scheme was developed which separated the TAP mutein from improperly processed peptides present in the medium. This scheme employed cation-exchange chromatography and reversed-phase HPLC. Scale-up of the process was successful and produced 100 mg of fully functional TAP mutein of >96% homogeneity from a 50-L yeast culture.

Amino Acid Sequence↗

PubMed1998

Nested insertions of short mobile sequences in Drosophila P elements.

A potentially full-sized P element isolated from the genome of Drosophila ambigua by polymerase chain reaction amplification was completely sequenced. It has a length of 3329 bp and the termini are formed by 33 bp inverted repeats. Sequence comparisons show that it can be classified as a member of the T-type P element subfamily. The translational reading frames of all four exons are interrupted by stop codons and frameshift mutations. At the 3' end of exon 3 a 687 bp insertion sequence (IS-amb-P) is found that also occurs in the form of dispersed copies (IS-amb) in the genome in D. ambigua. At the interspecific level it shows homology to mobile sequences of other species of the obscura group. Although variable in length, these IS elements are characterized by conserved sections without coding function and by 14 bp inverted repeats, one at a terminal, the other at a subterminal position. In situ hybridization revealed that P elements in D. ambigua are restricted to only two euchromatic sites on chromosome elements A and E. This situation resembles that found in Drosophila guanche and Drosophila subobscura where P homologs are clustered at a single site on chromosome element E and where the section corresponding to exon 3 of P elements carries an IS element. The gene sik-hom, which is located at the 5' side of the D. guanche cluster of P homologs, was used as a marker to examine whether the P element sites on chromosome element E of D. guanche and D. ambigua are homologous. The results suggest that the nested insertions of IS elements into P elements must have occurred independently in the two different lineages.

Amino Acid Sequence↗

PubMed1998

Ganciclovir susceptibilities and analysis of UL97 region in cytomegalovirus (CMV) isolates from bone marrow recipients with CMV disease after antiviral prophylaxis.

Ganciclovir susceptibilities and UL97 sequences were analyzed in 20 cytomegalovirus (CMV) isolates recovered from 15 bone marrow transplant recipients with active CMV infection after prophylaxis with acyclovir (group I; 12 isolates) or after acyclovir prophylaxis followed by ganciclovir therapy (group II; 8 isolates). All group I isolates were susceptible to ganciclovir. Five group II isolates were susceptible to ganciclovir, and 3 isolates (all from the same person) were resistant to ganciclovir (IC50 > 12 microM). Ganciclovir resistance UL97 mutations were found in 4 group II isolates, including a ganciclovir-susceptible isolate obtained from 1 patient after 41 days of therapy with ganciclovir and 3 ganciclovir-resistant isolates obtained from another patient after 73, 116, and 132 days of treatment with ganciclovir. Ganciclovir-resistant CMV isolates may emerge rapidly in bone marrow transplant recipients who are treated with ganciclovir after receiving prophylaxis with acyclovir.

Acyclovir↗

PubMed1997

Autologous bone marrow versus non-mobilized peripheral blood stem cell transplantation for lymphoid malignancies: a prospective, comparative trial.

Autologous transplantation using bone marrow stem cells (BMSC) or peripheral blood stem cells (PBSC) is widely used for non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). We report a randomized, comparative trial comparing BMSC vs. non-mobilized PBSC for responsive NHL or HD. Patients randomized to BMSC (n = 13) vs. PBSC (n = 15) had more rapid neutrophil recovery (median 23 vs. 30 days), RBC independence (25 vs. 62 days), platelet independence (24 vs. 54 days), and shorter hospital stay. However, neither relapse, overall survival, nor relapse-free survival were different receiving BMSC vs. PBSC (all P > .7). Concurrently, 54 others (34 BMSC, 20 PBSC) were assigned non-randomly because of resistant disease or marrow unsuitable for harvest and similar patterns of engraftment favoring BMSC over PBSC were observed. In the entire group, BMSC transplantation (n = 47) led to quicker neutrophil recovery (P = .02), RBC (P = .06), and platelet independence (P =.04) and earlier hospital discharge (P = .02) vs. PBSC (n = 35). No difference in relapse, overall, or relapse-free survival were observed using BMSC vs. PBSC. These data suggest that non-mobilized PBSC are a satisfactory alternative to BMSC in patients with unsuitable marrow; however, transplantation with non-mobilized PBSC was associated with slower hematologic recovery, and longer hospital stay. No difference in tumor recurrence rates was observed between the PBSC or BMSC recipients. Unprimed PBSC transplantation offered no clinical advantage to BMSC.

Adolescent↗

PubMed1997

LTR retrotransposons and the evolution of eukaryotic enhancers.

Since LTR retrotransposons and retroviruses are especially prone to regional duplications and recombination events, these viral-like systems may be especially conducive to the evolution of closely spaced combinatorial regulatory motifs. Using the Drosophila copia LTR retrotransposon as a model, we show that a regulatory region contained within the element's untranslated leader region (ULR) consists of multiple copies of an 8 bp motif (TTGTGAAA) with similarity to the core sequence of the SV40 enhancer. Naturally occurring variation in the number of these motifs is correlated with the enhancer strength of the ULR. Our results indicate that inter-element selection may favor the evolution of more active enhancers within permissive genetic backgrounds. We propose that LTR retroelements and perhaps other retrotransposons constitute drive mechanisms for the evolution of eukaryotic enhancers which can be subsequently distributed throughout host genomes to play a role in regulatory evolution.

Animals↗

PubMed1997

Molecular domestication of mobile elements.

Transposable elements are ubiquitous in all organisms and represent a dynamic component of their genomes, causing mutations and thereby genetic variation. Because of their independent and expansive replication strategy, these elements are called selfish and were thought to have no impact on the adaptive evolution of their host organisms. Although most TE-induced mutations seem to exert only negative effects on the fitness of their carrier, recent evidence indicates that in the course of evolution at least some TE-mediated changes have become established features of the host genome. For example, the insertion of TEs may provide novel cis-regulatory regions to preexisting host genes or TE-derived trans-acting factors may undergo a molecular transition into novel host genes through a process described as molecular domestication. The stationary P element related gene clusters of D. guanche, D. madeirensis and D. subobscura provide an excellent model system to study the evolutionary impact of TEs on genome evolution. Each cluster unit consists of a cis-regulating section composed of different insertion sequences followed by the first three exons of a P element that are coding for a 66 kDa 'repressor-like' protein.

Animals↗

PubMed1996

Preferential targeting of oxidative base damage to internucleosomal DNA.

The structure of nuclear chromatin may limit the accessibility of carcinogenic agents to DNA. In the case of oxidative DNA strand cleavage mediated by the physiologically relevant iron chelate, iron-ADP, histone-associated nucleosomal DNA is protected while internucleosomal DNA is susceptible to damage. We now find that the distribution of iron-ADP-generated 8-hydroxydeoxyguanosine, a potentially mutagenic oxidative base change, shows relative targeting to internucleosomal sites (3.5-fold increased oxidative modification of internucleosomal compared with nucleosomal DNA as the minimal degree of enrichment). In contrast, iron-EDTA, which generates hydroxyl radical in the 'fluid phase', does not target internucleosomal DNA. Thus, physiologic iron chelates may promote site-specific damage and thereby be relevant to mechanisms of iron-dependent oxidative mutagenesis and carcinogenesis.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed1996

Structure and organization of the P element related sequences in Drosophila madeirensis.

The P element homologous sequences of the two closely related species Drosophila guanche and Drosophila subobscura represent a very special case of transposable-element derivatives. Although they have lost the regions known to be essential for P transposition by random mutations, all of them have selectively conserved the coding capacity for "P-repressor-like" proteins during the past few millions years. In both species, they are tandemly amplified in a single euchromatic gene cluster at equivalent chromosomal positions. In contrast, Drosophila madeirensis, an endemic species that is very closely related to both D. subobscura and D. guanche, harbours an additional P homologous site. Several mechanisms can be invoked to explain the generation of the new site in this species. In this work we present several molecular and cytological data in order to elucidate the possible evolutionary origin of the P derivatives of D. madeirensis.

Amino Acid Sequence↗

PubMed1996

Related donor marrow transplant for chronic myeloid leukemia: patient characteristics predictive of outcome.

Pre-transplant characteristics of 137 consecutive patients (including 103 patients with one or more features suggesting advanced disease) undergoing related donor marrow transplant for chronic myeloid leukemia (CML) were analyzed to determine their association with outcome. Multivariate analysis identified increased recipient age (relative risk (RR) for patients over 30 years of relapse or death 2.37; P = 0.004), and longer interval between diagnosis and transplant (RR 1.20; P = 0.0001) as significant adverse influences on disease-free survival (DFS). The 5-year DFS for patients transplanted within 1 year of diagnosis (¿early transplant', n = 71) was significantly higher (51%) than that for patients transplanted beyond 1 year from diagnosis ('delayed transplant', n = 55) (34%; log rank P = 0.02). For early transplant patients, poor prognostic features included myelofibrosis (RR 3.53; P = 0.018), splenomegaly (RR 2.22; P = 0.029) and the use of a female donor (RR 3.16; P = 0.002). The 5-year DFS for patients transplanted within 1 year of diagnosis and without signs of advanced disease was 67%. The presence of increasing numbers of features suggesting acceleration prior to transplant had a cumulative adverse influence of DFS. The risk of relapse (5 year estimate 20%) was also independently and significantly increased in association with a longer interval from diagnosis to transplant (P = 0.012). Early transplant is an important influence on DFS and relapse after related donor transplant therapy for CML, although additional patient characteristics influencing outcome can be identified and may have cumulative adverse effects.

Adolescent↗

PubMed1995

Unrelated donor bone marrow transplantation: influence of HLA A and B incompatibility on outcome.

We have studied the outcome of 211 consecutive unrelated donor (URD) bone marrow transplants (BMT) performed at the University of Minnesota (Minneapolis, MN) between May 1985 and December 1992. Ninety patients (43%) received marrow matched serologically at HLA A, B, and DR loci; 86 (41%) received marrow with a major and 32 (15%) marrow with a minor serologic mismatch at the HLA A or B locus. Multivariate analysis revealed that older age had an adverse effect on survival. In younger (age less than 18 years) recipients, survival after fully matched (A, B, and DR sub-type) or major mismatched (A or B locus), DR subtype-matched donor BMT was not significantly different (P = .4; survival: 53% v 41%, respectively, at 3 years). For adults, survival after matched donor BMT was significantly better than that with mismatched donors (P < .01; survival: 30% v 10%, respectively, at 3 years). Formal quality of life assessment by telephone interview demonstrated similar functional status in survivors of URD and related donor (RD) BMT at least 2 years post-BMT. URD BMT provides effective therapy for a variety of lethal hematopoietic diseases that rivals outcome of RD transplant in some cases. Use of URD marrow with a major mismatch at one HLA A or B locus is well tolerated in young, but not in older, recipients. These observations should be used to improve donor selection and counseling for URD BMT candidates.

Adolescent↗

PubMed1995

Structure and expression of clustered P element homologues in Drosophila subobscura and Drosophila guanche.

Sequence relationships and functional aspects were analysed in the P element homologues of Drosophila subobscura (Ds) and D. guanche (Dg). In both species, the P homologues are clustered at a single genomic position. They lack the characteristic terminal structures of actively transposing P elements, but they have the coding capacity for a 66-kDa 'repressor-like' protein. Two different types of cluster units (G-type and A-type) can be distinguished. The A-type unit, which is present in multiple copies, is transcribed in adult flies. In contrast, the G-type unit has a much lower copy number and is apparently not expressed. In Dg, the isolated G-type sequence carries a 420-bp insertion in the promoter region, which is probably responsible for inactivation. Sequence comparisons of different cluster units show that differentiation of the two types precedes the lineage split of these species. Substitution rates of the deduced proteins reveal two distinct subregions: high variability at the N terminus and strong sequence conservation in the rest of the protein. The variable region contains motifs characteristic of DNA-binding proteins. Adaptive diversification of the cluster units towards specific binding properties might be a plausible explanation for variability in the N-termini. Both unit types have lost the weak promoter region characteristic of P transposons. In the A-type unit, a new promoter has been formed which is apparently composed of parts of insertion sequences derived from two different mobile elements.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1995

Imaging findings in Caroli's disease.

In 1958 Jacques Caroli described communicating cavernous ectasia of the biliary tree as an uncommon cause of chronic, often life-threatening hepatobiliary disease. The disease now most often referred to as Caroli's disease is a rare condition characterized by nonobstructive saccular or fusiform dilatation of the intrahepatic bile ducts. In the so-called pure form, dilatation is classically segmental and saccular and is associated with stone formation and recurrent bacterial cholangitis. In the form associated with congenital hepatic fibrosis, bile duct dilatation usually is less prominent; portal hypertension and eventual liver failure typically develop as a result of the hepatic fibrosis. Caroli's disease usually is manifested in childhood and is thought to be congenital and probably inherited. Associated conditions include renal cystic disease, choledochal cysts, and cholangiocarcinoma. This pictorial essay illustrates the broad spectrum of imaging findings in Caroli's disease.

Adolescent↗

PubMed1995

Autologous stem cell transplantation for refractory and relapsed Hodgkin's disease: factors predictive of prolonged survival.

We analyzed patient, disease, and treatment related factors associated with long-term disease-free survival (DFS) in 62 patients with refractory or recurrent Hodgkin's disease treated with high-dose cyclophosphamide (6000 mg/m2), carmustine (BCNU; 300 mg/m2), and etoposide (900 mg/m2) (CBV) followed by autologous stem cell transplantation. There were no deaths resulting from toxicity of the preparative regimen, and all patients survived the peritransplant period. At 28 days post-transplant, the complete response (CR) rate was 76%. Patients who achieved a CR had a 50% estimated 3-year DFS (95% CI, 35-64%). Twenty-three (37%) patients remain in continuous clinical remission 1.3 to 7.7 years (median 3.8 years) after transplantation. In a univariate analysis, factors significantly associated with improved DFS included absence of B symptoms (fever, night sweats and unexplained weight loss) at transplant, response to pre-transplant salvage chemotherapy, less tumor bulk at time of transplant, and fewer prior treatment regimens. Stepwise multivariate analysis showed that the absence of B symptoms at time of transplant was independently and significantly associated with improved DFS after transplantation. CBV with autologous stem cell support can produce durable remissions with acceptable toxicity in a substantial proportion of patients who are asymptomatic at time of transplant. Earlier application of transplantation or development of additional effective antineoplastic modalities will be required to improve the results of transplantation for patients with advanced Hodgkin's disease.

Adolescent↗

PubMed1995

Autologous bone marrow transplantation for non-transformed low-grade non-Hodgkin's lymphoma.

The purpose of this study was to evaluate autologous bone marrow transplantation (ABMT) for low-grade non-Hodgkin's lymphoma (NHL). Between 1983 and 1994, 34 patients with non-transformed low-grade NHL received high-dose chemoradiotherapy plus stem cell rescue with marrow or peripheral blood. At transplantation (5-182 months (median 32) after diagnosis), 2 patients were in complete remission (CR), 21 in partial remission (PR) or minimal disease; 11 had bulky/resistant disease. Four patients died from transplant-related causes and 10 from lymphoma progression. After 40 months median follow-up, 20 survive between 3+ and 88+ months after ABMT. One-year survival is 81% (95% confidence interval, 65-96%) and 5-year survival 37% (14-60%). The probability of relapse at 1 and 2 years is 53% (34-72%) and 75% (54-96%), respectively. Twenty-nine patients were in CR following ABMT and 11 survive in continuous CR 3 to 54 months later. Disease-free survival at 1 and 2 years is 35% (19-52%) and 18% (2-31%). Resistant disease was the only factor significantly associated with poor overall (relative risk = 3.0, P = 0.04) and disease-free survival (RR = 5.4, P = 0.003), while resistant disease and high LDH were associated with increased relapse. ABMT yields a high CR rate for patients with progressive low-grade NHL, but relapse is frequent. Even longer follow-up is required to determine its effectiveness in extending survival of patients with pre-transplant responsive disease.

Adult↗

PubMed1994

Two distinct P element subfamilies in the genome of Drosophila bifasciata.

The genome of Drosophila bifasciata harbours two distinct subfamilies of P-homologous sequences, designated M-type and O-type elements based on similarities to P element sequences from other species. Both subfamilies have some general features in common: they are of similar length (M-type: 2935 bp, O-type: 2986 bp), are flanked by direct repeats of 8 bp (the presumptive target sequence), contain terminal inverted repeats, and have a coding region consisting of four exons. The splice sites are at homologous positions and the exons have the coding capacity for proteins of 753 amino acids (M-type) and 757 amino acids (O-type). It seems likely that both types of element represent functional transposons. The nucleotide divergence of the two P element subfamilies is high (31%). The main structural difference is observed in the terminal inverted repeats. Whereas the termini of M-type elements consists of 31 bp inverted repeats, the inverted repeats of the O-type elements are interrupted by non-complementary stretches of DNA, 12 bp at the 5' end and 14 bp at the 3' end. This peculiarity is shared by all members of the O-type subfamily. Comparison with other P element sequences indicates incongruities between the phylogenies of the species and the P transposons. M-type and O-type elements apparently have no common origin in the D. bifasciata lineage. The M-type sequence seems to be most closely related to the P element from Scaptomyza pallida and thus could be considered as a more recent invader of the D. bifasciata gene pool. The origin of the O-type elements cannot be unequivocally deduced from the present data.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1994

Myelodysplastic syndrome after autologous bone marrow transplantation: an additional late complication of curative cancer therapy.

Myelodysplastic syndrome (MDS) is a complication of conventional antineoplastic therapy but has rarely been reported after autologous bone marrow transplantation (ABMT). We reviewed records of 206 patients who underwent ABMT for lymphoma at the University of Minnesota (Minneapolis, MN) between 1974 and 1993. Of 206 patients who underwent ABMT for non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD), 9 patients developed an MDS or secondary acute leukemia between 5 and 60 months (median 34 months) post-BMT. Two patients had relapsed after transplant and received additional therapy before the diagnosis of MDS. They were censored from the statistical analysis, resulting in a cumulative incidence of 14.5% +/- 11.6% (95% confidence interval) at 5 years. Three patients (15.2% +/- 18.0%) had HD, and four (14.0% +/- 14.7%) had NHL. In vitro BM purging had no affect on the incidence of MDS, although patients receiving peripheral blood stem cells had a projected MDS incidence of 31% +/- 33% versus 10.5% +/- 12% if BM cells were used (p = .0035). The patients had received a median of 14 cycles (range, 6 to 40) of chemotherapy before autologous transplantation; Five of nine patients received radiation therapy before BMT conditioning, and all patients received radiation before the diagnosis of MDS. No BM cytogenetic abnormalities were evident pretransplant in three of three patients studied, and all nine had normal pretransplant BM morphology. All patients had morphologic BM findings typical of MDS, and six of six studied had clonal cytogenetic abnormalities. At the diagnosis of MDS, all nine patients were without clinical, radiographic, or autopsy evidence of recurrent lymphoma; Three of the nine patients have died from complications of cytopenias at 23, 36, and 45 months after transplant (3 to 10 months after the diagnosis of MDS), whereas 6 survive 8 to 63 months after transplantation (1 to 34 months post-MDS). These data emphasize the cumulative leukemogenic potential of standard and salvage radiation and chemotherapy regimens and highlight treatment-induced MDS as an important and frequent late complication of potentially curative BM transplant therapy.

Adult↗

PubMed1994

Structural characterization of the N-glycans of a humanized anti-CD18 murine immunoglobulin G.

This study characterized the N-glycans of a humanized immunoglobulin G4 (IgG4) expressed in NS/O mouse myeloma cells and directed against the CD18 family of adhesion-promoting receptors on leukocytes. The N-glycans were released from the purified recombinant IgG by N-glycanase treatment, purified by Sephadex G50 chromatography, and fractionated by Bio-Gel P-4 chromatography into three oligosaccharide pools. Each pool was analyzed individually by glycosyl composition analysis, high-pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), 600-MHz 1H-NMR spectroscopy, and electrospray-ionization mass spectrometry. In addition, each of the three pools was subfractionated by HPAEC and the isolated subfractions that contained sufficient material were hydrolyzed and analyzed for glycosyl composition by HPAEC-PAD. The overall results indicate the presence of five oligomannoside-type structures (containing 5 to 8 Man residues) which are not usually found in IgG, and the presence of eight diantennary (mostly truncated) N-acetyllactosamine-type structures which are typical of mouse and human IgGs. The N-acetyllactosamine-type structures were heterogeneous with regard to alpha(1-->6) fucosylation of the linkage GlcNAc, and the presence or absence of GlcNAc and/or Gal beta(1-->4)GlcNAc extending the core pentasaccharide (Man3GlcNAc2). No evidence was found for the presence of sialic acid or bisecting GlcNAc residues on the N-acetyllactosamine-type chains. The latter finding suggests that the N-glycans of this humanized IgG are of the mouse type.

Animals↗

PubMed1994

Time course of purine protection against kainate-induced increase in hippocampal [3H]-PK11195 binding.

Binding of a peripheral benzodiazepine receptor ligand was used to quantify the reactive gliosis resulting from neuronal damage induced by systemic injections of kainic acid 7 days previously. The enhancement of binding in rat hippocampus could be prevented by injections of the purine analogue (R)-N6-phenylisopropyladenosine at 25 microgram/kg up to 2 h before or after the toxin. These results indicate that the purine is able to prevent neurotoxicity by interrupting events occurring some time after kainate administration.

Animals↗