Biomedical subjects

B B Rosenblum

Publications and source records attributed to B B Rosenblum.

At least 19 recordsLinked to original sources

PubMed1998

Genotyping of forensic short tandem repeat (STR) systems based on sizing precision in a capillary electrophoresis instrument.

Automated fluorescence analysis of polymerase chain reaction (PCR)-amplified short tandem repeat (STR) systems by capillary electrophoresis (CE) is becoming an established tool both in forensic casework and in the implementation of both state and national convicted offender DNA databases. A new capillary electrophoresis instrument, the ABI Prism 310 Genetic Analyzer, along with the Performance Optimized Polymer 4 (POP-4) provides an automated and precise method for simultaneously analyzing ten fluorescently labeled STR loci from a single PCR amplification kit, which provides a power of discrimination of approximately one in five billion from a single PCR amplification. Data are presented on sizing precision, sizing accuracy, and resolution for the STR loci in the AmpFlSTR Profiler kit. Sizing accuracy is highly dependent on the electrophoresis system, and therefore the reporting of alleles based on the nucleotide size obtained from an electrophoresis system is not recommended for forensic work. The precision of the 310 capillary electrophoresis system, coupled with software developed for automated genotyping of alleles based on the use of an allelic ladder, allows for accurate genotyping of STR loci. Sizing precision of < or = 0.16 nucleotide standard deviation was obtained with this system, thus allowing for accurate genotyping of length variants that differ in length by a single nucleotide.

Alleles↗

PubMed1998

High-precision genotyping by denaturing capillary electrophoresis.

Genotyping, as applied to linkage mapping, human identification, or mapping of genetic traits, mandates electrophoretic separation systems that enable a user to identify alleles with high precision to obtain a correct genotype. For 2-bp microsatellites or short tandem repeats (STRs), standard deviations of +/-0.3 nucleotide are required to ensure with 99.7% probability the identity or dissimilarity of tested alleles. A complete system, consisting of commercially available laser-induced fluorescence capillary electrophoresis (ABI PRISM 310) and performance optimized polymer 4 (POP-4), was evaluated for microsatellite separations. POP-4 is a low viscosity polymer for use in uncoated fused microbore silica capillaries. It separates DNA fragments that differ in size by 1 nucleotide up to 250 nucleotides and that differ in size by 2 nucleotides for fragments up to at least 350 nucleotides in length in about 30 min. The presence of denaturants and, more importantly, operation at 60 degrees C was mandatory for high-precision and high-resolution sizing operation. Reproducible separation performance was achieved in excess of 100 injections per capillary with resulting standard deviations in the range of 0.04 to 0.17 nucleotide. Comparative sizing of known CEPH (Centre d'Etudes du Polymorphisme Humaine) samples performed at 22 independent test sites showed the usefulness of the system for genotyping with standard deviations of 0.24 nucleotide, or better.

Chromosome Mapping↗

PubMed1997

New dye-labeled terminators for improved DNA sequencing patterns.

We have used two new dye sets for automated dye-labeled terminator DNA sequencing. One set consists of four, 4,7-dichlororhodamine dyes (d-rhodamines). The second set consists of energy-transfer dyes that use the 5-carboxy-d-rhodamine dyes as acceptor dyes and the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein as the donor dye. Both dye sets utilize a new linker between the dye and the nucleotide, and both provide more even peak heights in terminator sequencing than the dye-terminators consisting of unsubstituted rhodamine dyes. The unsubstituted rhodamine terminators produced electropherograms in which weak G peaks are observed after A peaks and occasionally C peaks. The number of weak G peaks has been reduced or eliminated with the new dye terminators. The general improvement in peak evenness improves accuracy for the automated base-calling software. The improved signal-to-noise ratio of the energy-transfer dye-labeled terminators combined with more even peak heights results in successful sequencing of high molecular weight DNA templates such as bacterial artificial chromosome DNA.

DNA, Bacterial↗

PubMed1997

Improved single-strand DNA sizing accuracy in capillary electrophoresis.

Interpolation algorithms can be developed to size unknown single-stranded (ss) DNA fragments based on their electrophoretic mobilities, when they are compared with the mobilities of standard fragments of known sizes; however, sequence-specific anomalous electrophoretic migration can affect the accuracy and precision of the called sizes of the fragments. We used the anomalous migration of ssDNA fragments to optimize denaturation conditions for capillary electrophoresis. The capillary electrophoretic system uses a refillable polymer that both coats the capillary wall to suppress electro-osmotic flow and acts as the sieving matrix. The addition of 8 M urea to the polymer solution, as in slab gel electrophoresis, is insufficient to fully denature some anomalously migrating ssDNA fragments in this capillary electrophoresis system. The sizing accuracy of these fragments is significantly improved by the addition of 2-pyrrolidinone, or increased capillary temperature (60 degrees C). the effect of these two denaturing strategies is additive, and the best accuracy and precision in sizing results are obtained with a combination of chemical and thermal denaturation.

Algorithms↗

PubMed1997

New energy transfer dyes for DNA sequencing.

We have synthesized a set of four energy transfer dyes and demonstrated their use in automated DNA sequencing. The donor dyes are the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein and the acceptor dyes are a novel set of four 4,7-dichloro-substituted rhodamine dyes which have narrower emission spectra than the standard, unsubstituted rhodamines. A rigid amino acid linker, 4-aminomethylbenzoic acid, was used to separate the dyes. The brightness of each dye in an automated sequencing instrument equipped with a dual line argon ion laser (488 and 514 nm excitation) was 2-2.5 times greater than the standard dye-primers with a 2 times reduction in multicomponent noise. The overall improvement in signal-to-noise was 4- to 5-fold. The utility of the new dye set was demonstrated by sequencing of a BAC DNA with an 80 kb insert. Measurement of the extinction coefficients and the relative quantum yields of the dichlororhodamine components of the energy transfer dyes showed their values were reduced by 20-25% compared with the dichlororhodamine dyes alone.

Base Sequence↗

PubMed1990

Hemoglobin Warsaw (Phe beta 42(CD1)----Val), an unstable variant with decreased oxygen affinity. Characterization of its synthesis, functional properties, and structure.

In Hb Warsaw Val replaces the Phe normally present at the heme contact position beta 42 (CD1). This variant is unstable, and it readily undergoes methemoglobin formation. In DEAE-cellulose chromatography, the variant hemoglobin co-eluted with Hb A; a partially heme-depleted fraction of the variant, representing 5-6% of the total hemoglobin, eluted separately and in pure form. The heme replete form of Hb Warsaw exhibited decreased oxygen affinity with a normal Bohr effect and normal cooperativity and interaction with 2,3-diphosphoglycerate (DPG). The heme-depleted Hb Warsaw had a higher oxygen affinity than that of Hb A, decreased cooperativity and 2,3-DPG interaction, and a very low alkaline Bohr effect. Gel filtration of the heme-depleted form showed it to exist entirely as alpha beta dimers. Globin chain synthesis by Hb Warsaw-containing reticulocytes followed a balanced alpha/beta ratio. In short-term synthesis experiments, a major portion of incorporated radiolabeled L-leucine was recovered from the dimeric, heme-depleted Hb Warsaw fraction, suggesting that subunit association precedes the incorporation of heme into the beta subunits in the post-synthetic assembly of this hemoglobin. Structural analysis of deoxyhemoglobin containing roughly equal proportions of normal and variant beta chains showed that the replacement leaves a cavity next to the heme that is large enough to hold a water molecule, which may account for the instability of Hb Warsaw. The heme and the pyrrol nearest to ValCD1 tilt into the cavity. The resulting increase in the tilt of the proximal histidine relative to the heme plane, coupled with a possible stretching of the Fe-N epsilon bond may account for the low oxygen affinity.

2,3-Diphosphoglycerate↗

PubMed1989

Hb Warsaw (beta 42 Phe----Val): an unstable hemoglobin with decreased oxygen affinity. I. Hematologic and clinical expression.

Four members in two generations of a Polish-American family exhibited findings of congenital Heinz-body hemolytic anemia accompanied by cyanosis. Two of the affected family members have also developed severe pulmonary hypertension, with a fatal outcome in one of them. Blood from the affected individuals showed decreased oxygen affinity and contained elevated levels of methemoglobin. An unstable hemoglobin fraction underwent rapid precipitation following exposure of the red cell lysates to isopropyl alcohol or heat. This hemoglobin contained a newly identified abnormal beta chain with an amino acid substitution at the same position as that of Hb Hammersmith and Hb Bucuresti-Louisville.

Adult↗

PubMed1987

Identification and characterization of a human transthyretin variant.

An apparent Mr variant of plasma transthyretin (TTR), previously detected using 2-D PAGE, is the first reported occurrence of this type of human TTR variant. We characterized the variant TTR to determine the nature of this difference. Comparative tryptic peptide maps of variant and normal TTR and sequencing of peptides which differed indicated the variant contained a single amino acid substitution of valine for tyrosine at position 116. Because such a change requires two nucleotide substitutions, we postulate the variant arose through mutation in codon 116 of a heretofore unrecognized polymorphic or rare variant allele of TTR.

Amino Acid Sequence↗

PubMed1986

Characterization of the fertilization antigen 1 for the development of a contraceptive vaccine.

A fertilization antigen, FA-1, was purified from either deoxycholate- or lithium diiodosalicylate-solubilized murine testes by immunoaffinity chromatography using a monoclonal antibody, MA-24, which inhibited fertilization in vitro. The FA-1 was recovered at high (11.4) or low (2.8) pH using stepwise elution procedures of the deoxycholate or lithium diiodosalicylate extracts, respectively. Both of these fractions showed a single band of 47 kDa when analyzed by NaDodSO4/PAGE and silver staining. Following removal of the detergent and extensive dialysis at pH 5.8 or treatment with 0.15 M NaCl, even in the presence of detergent, a monomer of 23 kDa was detected. Two-dimensional PAGE of FA-1 showed, four or five polypeptides in the 47-kDa or 23-kDa range. The dialyzed FA-1 contained a major 23-kDa and a minor 48-kDa band when separated on both sucrose and cesium chloride gradients. High performance size-exclusion chromatography showed a major peak at 23 kDa and a minor peak at 50 kDa. Further analysis of the 23-kDa peak by reverse-phase chromatography resolved the antigen into three peaks, which gave similar two-dimensional gel patterns as the native FA-1. Lectin affinity chromatography on a lens culinaris column demonstrated that a part of the antigen was bound to the lectin while the rest was not. The FA-1 revealed a positive reaction with periodic-Schiff reagent and contained glucose and mannose, which together constituted 18.8% of the total antigen mass. Amino acid analysis showed a high percentage of aspartic acid, glutamic acid, serine, and glycine. As a single injection of MA-24 significantly reduced fertilization rates in vivo, the purified FA-1 is an attractive candidate for the development of contraceptive vaccine.

Amino Acids↗

PubMed1986

Biochemical characterization of a monoclonal antibody to the H type-2 antigen: comparison to other ABH antibodies.

Monoclonal and polyclonal antibodies to the ABH blood group antigens were tested for their specificity to glycoproteins with ABH activity on immunoblots of solubilized erythrocyte membranes. Immunoblots were stained with monoclonal antibody G10 to the H type-2 carbohydrate structure or with commercially prepared monoclonal and polyclonal antibodies to A, B, and H blood group antigens. G10 antibody specifically stained antigens in the regions that contain the erythrocyte membrane bands 3 and 4.5; the staining was proportional to the expected H content of the erythrocytes (O greater than A2 greater than B greater than A2B greater than A1 greater than A1B). No specific staining was observed with membranes derived from Oh (Bombay) erythrocytes which lack the H type-2 structure. A commercially prepared monoclonal anti-H did not specifically stain erythrocyte membrane antigens. Monoclonal and polyclonal anti-A specifically stained bands from A and AB but not O, B, or Oh erythrocytes (A1 greater than A1B greater than A2 greater than A2B). Polyclonal anti-B serum specifically stained bands from B and AB but not O, A, or Oh erythrocytes (B greater than A2B greater than A1B). However, no specific staining was observed in tests with monoclonal anti-B. Monoclonal antibodies G10 and anti-A and polyclonal anti-A and -B blood typing sera will be useful in the further characterization of the molecular nature of the ABH antigens.

ABO Blood-Group System↗

PubMed1986

Two-dimensional gel analysis of Sertoli cell protein phosphorylation: effect of short term exposure to follicle-stimulating hormone.

The response of cultured Sertoli cells to short term FSH stimulation was studied to elucidate early events involved in the hormone response of this cell type. The phosphorylation of proteins by [32P]orthophosphate-labeled cells was examined using two-dimensional polyacrylamide gel electrophoresis and autoradiography. FSH stimulation resulted in a variety of changes in the phosphoprotein labeling pattern. Within 5 min, unique phosphoproteins appeared in autoradiograms of treated cells. Increased labeling of vimentin was also noted. After 25 min of FSH stimulation, increases and decreases in apparent labeling intensity were evident in additional phosphoproteins that were constitutively labeled in control cultures. Changes in protein patterns in stained gels were also noted after acute hormone treatment. These observations demonstrate that Sertoli cells respond to hormonal stimulation in a detectable manner within 5 min. Cytoskeletal involvement in initial phases of hormone response is indicated. Mechanisms such as increased protein kinase activity, changes in protein kinase substrate affinity, increased protein turnover, or phosphatase activation may all contribute to the early events involved in Sertoli cell hormone response.

Animals↗

PubMed1986

Genetic analysis of thirty-three platelet polypeptides detected in two-dimensional polyacrylamide gels.

Two-dimensional gel electrophoresis followed by silver-staining was utilized to visualize platelet polypeptides for genetic analysis. A subset of 33 polypeptides that were most suited for scoring was selected. Families consisting of father-mother-child trios were studied. Thirty-six polypeptides of a total of 1,413 scored in children's gels exhibited the combination of a normal and a variant polypeptide. The observed index of heterozygosity of 2.55% is comparable to our previously reported findings for red cell proteins.

Blood Platelets↗

PubMed1985

Two-dimensional gel studies of genetic variation in the plasma proteins of Amerindians and Japanese.

Genetic variation has been studied in plasma samples from 107 Amerindian children and their parents, and 110 Japanese children and their parents by means of two-dimensional polyacrylamide gel electrophoresis. Twenty-three polypeptides were scored; the identity of nine of these is at present still unknown. Genetic variation was encountered in 11 of these polypeptides. We have previously reported that the index of heterozygosity was 6.2 +/- 0.7% for 20 "randomly selected", silver stained polypeptides scored for genetic variation in Caucasoids (Rosenblum et al. 1983b). For technical reasons only 11 of these 20 polypeptides could be routinely scored in preparations from the Amerindian samples. For these 11 polypeptides, the indices of heterozygosity in the three populations were: Amerindians, 4.5 +/- 0.6%; Japanese, 5.7 +/- 0.7%; Caucasoids, 8.0 +/- 1.1%. Even with these relatively small numbers some striking ethnic differences as regards individual polypeptides are apparent.

Adult↗

PubMed1985

Properties of the Syrian hamster phosphomannosyl receptor: an aggregate of low molecular weight proteins.

Phosphomannosyl receptor (PMR) isolated from Syrian hamster liver was purified to apparent homogeneity by affinity chromatography and one-dimensional PAGE. On one-dimensional PAGE, the receptor migrated with a Mr approximately equal to 215,000 as detected by a silver-staining reagent or by immunoblotting [utilizing antiPMR generated against purified hamster PMR (Mr 215,000) sequentially purified by affinity chromatography and NaDodSO4/PAGE]. On two-dimensional PAGE the receptor was partially dissociated into low-molecular weight components. The protein distribution on immunoblots of two-dimensional gels of hamster liver homogenates was nearly identical to that observed for purified hamster liver PMR. When liver homogenates were subjected to one-dimensional PAGE and immunoblotted under nonreducing conditions, an intensely labeled band that migrated with an apparent Mr of 43,000-49,000 was observed; under reducing conditions a single band with a Mr of 49,000 was observed. The low molecular weight compound was present in the soluble 130,000 X g supernatant but not in the particulate fraction of liver homogenates. An immunoreactive component of similar molecular weight was also present in hamster serum and plasma. These results suggest that PMR is either an aggregate comprised of small molecular weight components or, alternatively, that a number of small molecular weight components are tightly associated with PMR.

Animals↗

PubMed1985

Peripheral blood erythroid progenitors from patients with sickle cell anemia: HPLC separation of hemoglobins and the effect of a HbF switching factor.

We describe the use of HPLC for the separation and quantitation of hemoglobin and globin chains. Utilization of this sensitive technique allows the analysis of hemoglobin and globin chains in the total accumulated and newly synthesized hemoglobin. Using this methodology, we have studied the effect of a previously described HbF factor in fetal calf serum on peripheral blood BFUe-derived erythroblasts from patients with sickle cell anemia. As in previous studies of peripheral blood BFUe-derived erythroblasts from hematologically normal adults, this HbF factor promoted the increased synthesis of HbF in the BFUe-derived erythroblasts from the sickle cell anemia patients.

Anemia, Sickle Cell↗

PubMed1984

Independent regulation of nonallelic pancreatic amylase genes in diabetic mice.

Administration of streptozotocin produces a diabetic condition in mice characterized by a specific decrease in amylase synthesis in the pancreas as well as a substantial reduction in amylase mRNA concentration. We have studied this effect in mice of the congenic strains C3H.AmyYBR and C3H.AmyCE with multiple active copies of the pancreatic amylase structural gene. When mice of these strains are treated with streptozotocin, the magnitude of reduction in the synthesis of each amylase isozyme is different. These differences are reflected in the relative activities of isozyme-specific mRNAs in an in vitro translation assay. Administration of insulin results in partial restoration of normal phenotypes. The results provide genetic evidence that individual copies of the amylase structural gene are associated with divergent cis-acting insulin-responsive sequences.

Alleles↗

PubMed1984

Characterization of a membrane antigen from rabbit testis and sperm isolated by using monoclonal antibodies and effect of its antiserum on fertility.

An antigen was isolated from deoxycholate-solubilized rabbit testis and sperm by using an immunosorbent column containing IgG from a monoclonal antibody (8C10.5) that inhibits fertility. Elution was by stepwise increases in pH (8.0, 10.0, and 11.4), with the pH 11.4 fraction after recycling through the column showing a single band at 63 kilodaltons in slab NaDodSO4/PAGE with a silver stain. The antigen molecule was composed of two subunits, which on two-dimensional PAGE showed many spots within the same molecular size range (50-70 kilodaltons) but differing in charge. The antigen isolated either from testis or sperm showed mainly the same spots. The antigen is periodic acid/Schiff positive and contained 21% carbohydrate. An asialo-derivative of the antigen did not change its characteristics on NaDodSO4/PAGE. This glycoprotein resolved into two types of polypeptides, those binding and those not binding to a lens culinaris lectin column; some of the polypeptides appeared common to both fractions. Murine antiserum against the antigen neither agglutinated nor immobilized rabbit sperm but in immunofluorescence reacted with the plasma membrane of viable rabbit sperm as well as with murine and human sperm. Fertilization of female rabbits inseminated with treated sperm was not affected, but, by 9 days, fertility was significantly reduced (21% of controls). The postfertilization antifertility effect was not due to parthenogenic activation or to polyspermy. The antiserum reacted with one specific band in the one- and two-dimensional gel electrophoretic transfer blot procedure and was unaffected by absorption with different somatic tissues.

Animals↗

PubMed1984

Conserved linkage within a 4-cM region of mouse chromosome 9 and human chromosome 11.

A six-point cross was carried out to determine the gene order and distances among loci on mouse chromosome 9. Our results are consistent with the following arrangement: centromere - Lap-1 - (1.2 +/- 0.8) - Es-17 - (3.0 +/- 1.0) - Ups - (1.3 +/- 0.7) - Alp-1 - (23.1 +/- 3.4) - Mod-1 - (10.9 +/- 2.6) - Acy-1. This study provides the first estimate of the distances between Es-17, Ups and Alp-1. Exceptions to the preferred association of alleles of Es-17 and Ups have been found in three feral populations and one inbred strain. Evidence is presented for the homology of this chromosome region with the ESA4 - UPS - APO-AI region on the long arm of human chromosome 11.

Acetylesterase↗