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Biomedical subjects

B Best

Publications and source records attributed to B Best.

12 recordsLinked to original sources
PubMed1996

Specificity of antibodies directed against Env protein of human endogenous retroviruses in patients with germ cell tumors.

We report here that 85% of the patients with germ cell tumors (GCTs) produce antibodies directed against Env protein of human endogenous retroviruses. Individuals that received antitumor treatment showed a decrease with time in their antibody titers. Importantly, of the rare cases of non-GCT individuals with Env-antibodies (n= 15, 0.8%), none produced antibodies directed against the transmembrane domain (TM), whereas all tested Env-positive GCT patients (n= 49) generated such antibodies at high titers. TM is required for Env to be expressed at the cell surface. Thus, anti-TM antibodies constitute highly specific markers for GCT and may hint at a function of Env during tumorigenesis.

Animals↗
PubMed1996

Characterization of the human endogenous retrovirus K proteinase.

The proteinase of the human endogenous retrovirus K (HERV-K) shows similarity to retrovirus aspartic proteinases. It is translated from a transcript composed of gag and prt. The proteinase was expressed either as full-length native protein or as truncated protein in Escherichia coli. Functional protein was demonstrated by its autocatalytic cleavage into an 18 kDa fragment recognized by a polyclonal antiserum. This autocatalytic cleavage was specifically inhibited by a human immunodeficiency virus type 1 proteinase inhibitor. The HERV-K proteinase expressed in E. coli was capable of cleaving HERV-K Gag translated in vitro. Major protein fragments of 39 and 30 kDa, and minor protein fragments of 26, 22 and 21 kDa were obtained. Similar fragments are also observed in the human teratocarcinoma cell line Tera1. Our data suggest that the HERV-K proteinase is functionally equivalent to other retrovirus proteinases and thus probably functions in the processing of Gag precursor protein.

Endopeptidase K↗
PubMed1995

Human endogenous retrovirus K10: expression of Gag protein and detection of antibodies in patients with seminomas.

The human endogenous retrovirus K10 (HERV-K10) has been identified in the human genome by its homology to retroviruses of other vertebrates (M. Ono, T. Yasunaga, T. Miyata, and H. Ushikubo, J. Virol. 60:589-598, 1986). Using PCR amplification, DNA cloning, sequencing, and procaryotic expression, we were able to demonstrate that HERV-K10 encodes a 73-kDa protein which was processed by a HERV-K10-encoded protease to yield proteins p22/p26, p30, and p15/16. Analysis of the teratocarcinoma cell line Tera 1 or tumor tissues by immunoblotting demonstrated that the 80-kDa polyprotein of HERV-K10 gag and a processed protein of 39 kDa were expressed. In addition, a major protein of 39 kDa and additional species of 30, 22, 19, and 17 kDa could be detected in the supernatant of Tera 1 cells, suggesting that HERV-K10 Gag proteins are either secreted or processed to probably incomplete viral particles. In addition, the gag gene of HERV-K10 was expressed in the baculovirus system. Using this recombinant system to test antisera from patients with different diseases and healthy individuals, we were able to detect antibodies against the N-terminal part of HERV-K10 Gag in 2 to 4% of groups of tumor patients with titers ranging between 1:80 and 1:640, while approximately 0.1 to 0.5% of healthy individuals exhibited antibodies with lower titers. In contrast, patients with seminoma had antibody titers in the range of 1:2,560 at the time when the tumor was detected. Immunohistochemistry using specific rabbit sera or monoclonal antibodies against HERV-K10 Gag revealed that the Gag protein is expressed in the cytoplasm of the tumor cells. Furthermore, an 80-kDa protein corresponding to the HERV-K10 Gag polyprotein could be detected in tumor biopsies. For the first time, these data indicate that HERV-K10 Gag proteins are synthesized in seminoma cells and tumors exhibit relatively high antibody titers against Gag. So far, no information on which role HERV-K10 plays in the development of this tumor exists.

Antibodies, Viral↗
PubMed1994

WHEN DOES MOTION RELATIVE TO NEIGHBORING SURFACES ALTER THE FLOW THROUGH ARRAYS OF HAIRS?

Many animals from different phyla use structures bearing arrays of hairs to perform a variety of important functions, such as olfaction, gas exchange, suspension feeding and locomotion. The performance of all these functions depends on the motion of water or air around and through these arrays of hairs. Because organisms often move such hair-bearing appendages with respect to their bodies or the substratum, we assessed the effects of such motion relative to walls on the fluid flow between neighboring hairs. We compared flow fields near dynamically scaled physical models of hairs moving near walls with those calculated for such hairs in an unbounded fluid. Our results suggest that the methods an organism can use to change the flow through a hair-bearing appendage differ with Reynolds number (based on hair diameter). When Re is 10(-2) or below, changing speed does not alter the proportion of the fluid that moves through rather than around the array, whereas moving relative to a wall increases it. In contrast, when Re is between 10(-2) and 1, changes in speed have a big effect on the proportion of fluid moving through the array, while moving near walls makes little difference.

Journal Article↗
PubMed1993

Human endogenous retroviral element K10 (HERV-K10) encodes a full-length gag homologous 73-kDa protein and a functional protease.

The gag-homologous region of the human endogenous retrovirus K10 (HERV-K10) was amplified by PCR from human genomic DNA and was analyzed by DNA cloning, sequencing, and expression of open reading frames in the prokaryotic pATH expression system. The analysis of genomic DNA of three donors provided evidence that HERV-K10 genes contain an open reading frame of 1966 bp spanning the entire gag-homologous region. In the prokaryotic system the entire reading frame of the HERV-K10 gag gene could be expressed as a fusion protein exhibiting a molecular weight of about 110,000. In addition, when the gag-homologous region and the adjacent HERV-K10 protease gene were prokaryotically expressed, we observed a Gag-protease fusion protein that exhibited specific autoproteolytic activities and processing of HERV-K10 Gag protein. By introducing deletions on the right end of the putative protease gene an autocatalytic site could be localized within 300 bp of the putative HERV-K10 protease gene. For the first time, these results provide evidence that the HERV-K10 encodes a full-length Gag protein and a functional protease.

Base Sequence↗
PubMed1989

Molecular epidemiology and restriction site mapping of adenovirus type 3 genome types.

One hundred thirty-eight strains of adenovirus type 3 isolated from patients in the United States, West Germany, and other regions between 1961 and 1984 were analyzed with six restriction endonucleases; 18 genome types were found. BglII was the most discriminative enzyme. Mapping of altered restriction sites was also performed for all six enzymes. The genome types D1 (like the prototype) and D3 prevailed among 45 and 47 strains, respectively. All genome types could be divided into two groups related to D1 or D3. Several clusters of infections by strains with the same genome type were observed. Only hints of differences were found in the pathogenicities of individual genome types. D1 strains were present in the United States and in Europe; group D3 prevailed almost exclusively in the United States.

Adenoviridae Infections↗
PubMed1987

Serologically atypical adenovirus strains of subgenus D are different in their genome from the respective prototypes.

Seven adenovirus strains of subgenus D, related to adenovirus types 8, 10, 13, 19, 23, 24 and 26, but atypical in their serological reactions or in hemagglutinin properties, were characterized by neutralization and hemagglutination-inhibition. DNA restriction analysis with five endonucleases showed that each of the strains was strikingly different from the respective prototype.

Adenoviruses, Human↗
PubMed1985

A proposal for naming adenovirus genome types, exemplified by adenovirus type 6.

A numerical code to denominate adenovirus (AV) genome types is proposed. Seven restriction endonuclease patterns are listed in alphabetical order (BamHI, BGlII, BstEII, EcoRI, HindIII, KpnI, SmaI); patterns deviating from those of the prototype (1) are named 2, 3 etc. depending on the chronological order of the respective isolates. Thus AV6/3:1231121 is a type 6 strain deviating from the prototype in three patterns, i.e. those of BglII, BstEII and KpnI. From 24 AV6 isolates, six were identical with the prototype, whereas the other strains represented 13 different genome types.

Adenoviruses, Human↗
PubMed1966

Overtime pay.

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Economics, Nursing↗
PubMedDate not supplied

Bacterial colonization of the upper respiratory tract and its association with acute lower respiratory tract infections in Highland children of Papua New Guinea.

Acute lower respiratory tract infection (ALRI) is the major cause of death among children in Papua New Guinea. This longitudinal study reports the bacteriologic findings for children observed in their hamlets. A total of 1,449 nasal swab specimens from 158 children less than 5 years of age who were studied intensively for 18 months were examined. Non-serotypable strains of Haemophilus influenzae were isolated from 91% of specimens, and serotypable strains were isolated from 35% (8% H. influenzae type b) of specimens. All children had acquired Streptococcus pneumoniae by the age of 3 months. The most frequently occurring serotypes of S. pneumoniae were 6, 19, and 23. Children more frequently carried invasive pneumococci during an episode of ALRI than when they were healthy. Also, children more frequently carried serotypable strains of H. influenzae during the 2 weeks preceding an episode of ALRI than when they were healthy. Between-children analyses showed that children who were susceptible to attacks of ALRI and those who were not susceptible had similar rates of carriage of bacteria.

Age Factors↗