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Biomedical subjects

H Will

Publications and source records attributed to H Will.

At least 199 records · Page 11Linked to original sources
PubMed1986

Developmental changes of Ca++ transport systems in chick heart.

Sarcolemma (SL) Na+/Ca++ exchange, binding of the Ca++ channel antagonist [3H]nitrendipine and sarcoplasmic reticulum (SR) Ca++ uptake were studied in crude membranes from developing chick heart. Energy-linked Ca++ uptake of mitochondria (MT) was measured in tissue homogenates. When reckoned per unit of heart mass Na+/Ca++ exchange increases linearly (20-fold) from embryonic day 4 to postnatal day 10. These changes correlate strongly with developmental variations of (Na+, K+)ATPase activity. The density of high-affinity [3H]nitrendipine receptors increases in parallel, while the specific affinity does not change SR Ca++ uptake rises steadily during embryogenesis and increases steeply (3-fold) at the time of hatching. Hearts of 10-day-old chickens exhibit 50-fold higher SR Ca++ transport activities than those of 4-day-old embryos. Between the latter stage and postnatal day 10 a more than 100-fold increase of MT Ca++ uptake occurs. The results suggest developmental variations in the contribution of single Ca++ transporting systems in cardiac Ca++ control.

Age Factors↗
PubMed1986

Purification of phospholamban and characterization of its antibodies.

Phospholamban was extracted from pig heart microsomal membranes with a methanol-chloroform (2:1) mixture. The proteolipid was further purified to electrophoretic homogeneity by chromatography in organic solvents and in SDS-containing medium. Purification was about 50-fold with respect to specific 32P-phospholamban radioactivity. Antisera were produced in rabbits against phospholamban. Electroblot analysis demonstrates specific binding of the antisera to purified phospholamban and to phospholamban in preparations of cardiac sarcoplasmic reticulum and sarcolemma.

Amino Acids↗
PubMed1985

[A serological criterion for Bechterew's disease. Demonstration of a new antibody specificity with polytene chromosomes].

A new antibody reacting with an antigen from polytene chromosomes of Drosophila melanogaster has been found in serum of patients with Bechterew's disease. This antigen-antibody system differs from other nuclear antibodies (anti-RNP, anti-Sm, anti-Ha/SS-B) in that it is not detectable by counter-immunoelectrophoresis. The antibody could be detected in 24 out of 62 Morbus Bechterew sera in which the antibody did not strictly correlate with the appearance of HLA-B27 antigen. The new antibody specificity is a specific serological finding in patients with Bechterew's disease and is therefore suitable for use as a diagnostic, and perhaps also as a prognostic test for this type of spondylarthritis till now assumed to be seronegative.

Adolescent↗
PubMed1985

Comparative sequence analysis of duck and human hepatitis B virus genomes.

We have cloned and sequenced an infectious, functionally active genome of a duck hepatitis B virus (DHBV). It is 3,021 base pairs (bp) in length and shows little DNA sequence homology to the genome of human hepatitis B virus (HBV). However, the amino acid sequences of predicted viral gene products are similar between DHBV and HBV, and the genome organization present in DHBV reflects that of HBV. As in the mammalian virus the long minus strand of the DHBV genome encodes three long overlapping reading frames designated as P, S, and C. The fourth open reading frame, termed X, is absent in DHBV. A comparison with a sequence of a second DHBV isolate [Mandart et al, Journal of Virology 49:782-792, 1984] revealed a nucleotide sequence variation of 5.6% and confirmed the presented overall gene organization of DHBV.

Animals↗
PubMed1985

Transcripts and the putative RNA pregenome of duck hepatitis B virus: implications for reverse transcription.

Duck hepatitis B virus (DHBV) is a DNA virus that replicates by reverse transcription. We have examined transcripts of DHBV to elucidate mechanisms of gene expression and replication. Three major transcripts were characterized and related to the expression of the genes for the core antigen (DHBcAg), the surface antigen (DHBsAg), and the pre-S/DHBs protein, respectively. They are unspliced and overlap partially since they start at different promoter sites, but they terminate near a common polyadenylation signal. The messenger RNA related to DHBcAg expression is the only major transcript of more than genome length and therefore also represents the putative template for reverse transcription (pregenome). Its structure predicts a strategy of replication of hepatitis B viruses different from that of retroviruses.

Animals↗
PubMed1985

Structure of human ferritin light subunit messenger RNA: comparison with heavy subunit message and functional implications.

Ferritin has a protein shell of 5 X 10(6) Da consisting of 24 subunits of two types, a heavier (H) chain of 21,000 Da and a lighter (L) chain of 19,000 Da. A cDNA clone of the messenger for the L subunit has been isolated from a human monocyte-like leukemia cell line. The clone contains an open reading frame of 522 nucleotides coding for an amino acid sequence matching 97% of the published sequence of human liver ferritin L subunit determined by sequenator, but it corresponds to only 55% of the reported amino acid sequence of a human liver H-subunit clone. Nevertheless, computer analysis of the subunit conformations predicted from the open reading frames of the L and H clones shows that most of the amino acid differences are conservative and would allow both subunits to form the five alpha-helices and beta-turns established by x-ray crystallography for horse spleen ferritin subunits. This suggests that L and H subunits are structurally interchangeable in forming an apoferritin shell. The 5' untranslated region of our human ferritin L clone has considerable homology with that of the rat liver ferritin L clone in the region immediately upstream from the initiator codon, notably showing an identical sequence of 10 nucleotides at the same position in both subunit clones that may participate in regulating the known activation of ferritin mRNA after iron administration. Extensive homology, including several blocks of nucleotides, was identified between the 3' untranslated regions of the human and rat L clones. The common structural features of the H and L subunits lead us to conclude that they have diverged from a single ancestral gene.

Base Sequence↗
PubMed1985

Infectious hepatitis B virus from cloned DNA of known nucleotide sequence.

The infectivity of cloned hepatitis B viral DNA (HBV) has been tested in chimpanzees to identify a fully functional HBV genome and to assess the risk associated with its handling. Only one of two HBV DNA sequence variants tested was shown to be infectious. "Clone purified" virus of predicted nucleotide sequence was produced from the infectious HBV DNA, and the cloned viral genome was identical in structure with naturally occurring HBV. Infection could be initiated independent of whether circular monomeric or plasmid integrated dimeric forms of the viral genome were inoculated, but the infectivity of the DNA depended on liver cell transfection or intrahepatic injection. Intravenous injection of high doses of infectious HBV DNA did not induce hepatitis, suggesting that there is virtually no risk associated with routine laboratory handling of cloned HBV DNA.

Animals↗
PubMed1985

[Integrated and nonintegrated hepatitis B virus DNA in liver tissue].

Liver tissue was taken in eight patients with virus hepatitis B and one patient with liver carcinoma by biopsy, as well as in seven other patients at post mortem. HBV-DNA was measured in these tissue specimens by hybridization. In four out of eight patients who had had biopsy, HBV-DNA could be found; in two patients it was present in integrated form. The same was true for the tumor tissue stemming from the patient with liver carcinoma. In five out of eight liver tissue specimens taken at post mortem HBV-DNA could be demonstrated as well; it was integrated into the host genom in two cases. It may be important to find out in patients with chronic hepatitis virus infection, if HBV-DNA is present in free or integrated form before antiviral treatment is considered.

Adult↗
PubMed1985

Determination of HBV DNA by a simplified method of spot hybridization.

Molecular hybridization was employed to detect HBV DNA in sera of patients with acute or chronic hepatitis, by a simplified version of the spot hybridization technique. HBV DNA was found in 21 out of 50 sera obtained in acute hepatitis B. Determination of HBV DNA was negative in sera of patients with hepatitis A, Epstein-Bar virus infections or other HBsAg-negative liver diseases. There was no cross-hybridization between HBV DNA and sera of patients with non-A, non-B hepatitis.

Acute Disease↗
PubMed1985

Determination of HBV DNA in serum in a case of needlestick hepatitis.

HBV DNA in serum was determined by modified spot hybridization. A nurse of the dialysis staff was inoculated via needlestick with blood of a HBsAg-positive hemodialysis patient, who had 2000 pg HBV DNA per milliliter serum. After insufficient passive immunization the nurse developed transient anicteric hepatitis B. HBV DNA was positive in sera of the recipient before and at the beginning of the elevation of transaminases.

Adult↗
PubMed1984

[Anti-HBc IgM in acute and chronic hepatitis B virus infection].

Hepatitis B core antigen (HBcAg) synthesized in E. coli was used for determination of immunoglobulin M class-specific antibodies against HBcAg. It was found that 98% of cases with acute hepatitis B surface antigen (HBsAg) positive hepatitis type B were anti-HBc immunoglobulin M (IgM) positive. Atypical hepatitis B was detected in 33% of anti-HBc-positive HBsAg-negative cases with acute hepatitis. Anti-HBc IgM was positive for 6 months in acute resolving hepatitis type B, whereas cases resulting in chronic hepatitis B remained anti-HBc IgM-positive for up to 900 days. Chronic HBsAg carriers with severe liver disease had anti-HBc IgM more often than individuals with minor liver damage; 83% of HBsAg-positive liver cirrhoses, 63% of chronic aggressive hepatitis, 50% of HBsAg-positive liver carcinoma, but only 17% of chronic persistent hepatitis or 7% of healthy blood donors were anti-HBc IgM-positive. Determination of anti-HBc IgM is useful in detecting atypical hepatitis B virus infections without HBsAg in serum and, with some restrictions, in discriminating acute and chronic hepatitis type B.

Acute Disease↗
PubMed1984

A new serologic marker in ankylosing spondylitis.

Sera of patients with ankylosing spondylitis (AS) were screened for the presence of antibodies by indirect immunofluorescence staining of polytene chromosomes of Drosophila melanogaster. Thirty-nine percent of the sera tested contained antibodies which selectively reacted with an antigen(s) present at the chromosomal locus 93D after heat shock treatment. This indicates a novel antibody specificity in a subgroup of AS patients and may provide a new aid in the diagnosis of AS.

Adolescent↗
PubMed1984

Hepatitis B virus transcription in the infected liver.

Hepatitis B virus (HBV) transcription was studied in the liver of an infected chimpanzee and compared with HBV transcription in heterologous systems. Besides the well characterized 2.3-kb surface antigen mRNA produced in most systems, a second major transcript was identified in the liver. This 3.8-kb transcript (+/- 300 bases) is slightly larger than the HBV genome and is probably involved both in core/e antigen synthesis and in HBV replication via reverse transcription. In addition, minor variants of the 2.3-kb surface antigen mRNA were characterized as probably being involved in the expression of HBsAg-related minor proteins. Finally, several potential transcription signals, identified on the HBV genome using heterologous expression systems, were found to be poorly active if at all in the infected liver, thereby stressing the importance of HBV transcription studies performed with liver material.

Animals↗
PubMed1984

A new sensitive method for qualitative and quantitative assay of neomycin phosphotransferase in crude cell extracts.

A general method is described for the detection and quantification of low amounts of neomycin phosphotransferase in crude cell extracts. The assay is based on the electrophoretic separation of the enzyme from other interfering proteins and detection of its enzymatic activity by in situ phosphorylation of the antibiotic kanamycin. Both kanamycin and [gamma-32P]ATP acting as substrates are embedded in an agarose gel placed on the polyacrylamide gel containing the separated proteins. After the enzymatic reaction, the phosphorylated kanamycin is transferred to P81 phosphocellulose ion exchange paper and the radiolabeled kanamycin is visualised by autoradiography. With this method 1 ng of active enzyme can easily be detected. Both prokaryotic and eukaryotic cell extracts can be examined, and changes in the size of enzymatically active proteins can be determined.

Animals↗
PubMed1984

Detection of hepatitis B viral DNA in sera positive for antibody to delta antigen.

Hepatitis B virus (HBV) DNA was detected in 17 sera positive for antibody to delta antigen (anti-delta). Six sera from two patients were positive for HBV DNA. Analysis by the Southern blot technique showed identity between HBV DNA in anti-delta-positive and anti-delta-negative sera. These results show that anti-delta-positive sera contain HBV DNA, although these sera were also positive for antibodies to hepatitis B e antigen.

DNA, Viral↗
PubMed1984

Expression of hepatitis B antigens with a simian virus 40 vector.

Recombinant DNA molecules consisting of the simian virus 40 (SV40) early region and different subgenomic hepatitis B virus DNA fragments were constructed in vitro and packaged in vivo into SV40 capsids by using a complementing SV40 helper virus. Upon infection with these virus stocks the three known hepatitis B-specific antigens were expressed under SV40 control. The surface antigen was released into the medium, and the core antigen and its derivative hepatitis B e antigen were only detected intracellularly. Size analysis of the core gene product(s) by immunoblotting revealed the presence of a single protein species identical with the 21-kilodalton core antigen isolated from human liver. The hepatitis B core antigen expressing construct did not contain a putative precore sequence, indicating that such a sequence is not needed for hepatitis B core antigen synthesis in animal cells. S1 analysis demonstrated the use of SV40 signals for initiation and polyadenylation of the core gene transcripts. In addition, a processing-polyadenylation signal was identified within the core gene.

Cell Line↗