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Biomedical subjects

E Schwarz

Publications and source records attributed to E Schwarz.

At least 127 records · Page 7Linked to original sources
PubMed1988

Small angle X-ray scattering study on bovine porphobilinogen synthase (5-aminolaevulinate dehydratase).

The quaternary structure of the native (zinc) porphobilinogen synthase (5-amino-laevulinate dehydratase) from bovine liver and its lead-substituted derivative is studied in solution by small angle X-ray scattering. In spite of the profound inhibitory effect of lead ions in the enzyme they do not produce a change in the quaternary structure detectable by small angle X-ray scattering. The most important molecular parameters of the native enzyme were found to be: radius of gyration Rg = 4.04 +/- 0.04 nm and maximum dimension Dmax = 12.0 +/- 0.5 nm. The corresponding values for the lead derivative are: Rg = 4.26 +/- 0.1 nm and Dmax = 12.5 +/- 0.5 nm. The quaternary structure of the enzyme in solution is described by a model, which fits the experimental scattering and distance distribution function.

Animals↗
PubMed1987

Papillomavirus sequences integrate near cellular oncogenes in some cervical carcinomas.

The chromosomal locations of cellular sequences flanking integrated papillomavirus DNA in four cervical carcinoma cell lines and a primary cervical carcinoma have been determined. The two human papillomavirus (HPV) 16 flanking sequences derived from the tumor were localized to chromosome regions 20pter----20q13 and 3p25----3qter, regions that also contain the protooncogenes c-src-1 and c-raf-1, respectively. The HPV 16 integration site in the SiHa cervical carcinoma-derived cell line is in chromosome region 13q14----13q32. The HPV 18 integration site in SW756 cervical carcinoma cells is in chromosome 12 but is not closely linked to the Ki-ras2 gene. Finally, in two cervical carcinoma cell lines, HeLa and C4-I, HPV 18 DNA is integrated in chromosome 8, 5' of the c-myc gene. The HeLa HPV 18 integration site is within 40 kilobases 5' of the c-myc gene, inside the HL60 amplification unit surrounding and including the c-myc gene. Additionally, steady-state levels of c-myc mRNA are elevated in HeLa and C4-I cells relative to other cervical carcinoma cell lines. Thus, in at least some genital tumors, cis-activation of cellular oncogenes by HPV may be involved in malignant transformation of cervical cells.

Attachment Sites, Microbiological↗
PubMed1987

[Childhood stress and neurosis--results of a control group study].

Biographical stress-risk was compared between a group of 68 neurotic-psychosomatic patients and a parallel control group matched in terms of age and sex. This risk rate was established using a so-called risk-index in which 8 known and variably weighted risk factors were taken into consideration. The following hypotheses were confirmed in the study: Neurotically ill persons show a higher stress-risk (risk-index) in their childhood and pre-adolescence than is found in healthy persons. A person's stress-index is related to the degree of neurosis (r = .42).

Adult↗
PubMed1986

Molecular cloning and characterization of the DNA of a new human papillomavirus (HPV 30) from a laryngeal carcinoma.

DNA from a human laryngeal carcinoma was molecularly cloned in Lambda L47. The gene library was screened for human papillomavirus (HPV)-related sequences by hybridization analysis with 32P-labelled HPV 16 DNA at conditions of low stringency (Tm -40 degrees C). One of the clones (4-5) with an insert of 7.8 kb showed cross-hybridization with most of the known HPV types (Tm -40 degrees C), and with several of them even under more stringent conditions (Tm -30 degrees C). No signal was detected under high-stringency conditions (Tm -20 degrees C). The co-linear alignment of clone 4-5 with HPV 16 DNA could be demonstrated by hybridization experiments and also by partial DNA sequence analysis. We conclude that clone 4-5 represents a new HPV type tentatively designated HPV 30. HPV 30 DNA was also detected in 2 genital lesions but not in 41 laryngeal carcinomas analyzed so far. Its presence in other tumor DNA is now under investigation.

Base Sequence↗
PubMed1986

Persistence and expression of human papillomavirus DNA in genital cancer.

There is mounting evidence that certain types of human papillomaviruses (HPV types 16 and 18) are associated with human genital cancer. Other virus types, such as HPV-6 or HPV-11, are more regularly found in benign genital warts. Since all viruses can be present in putative precancerous lesions of the uterine cervix (dysplasia, cervical intraepithelial neoplasia) it has been postulated that individual HPV types have different 'oncogenic potential'. The molecular basis for this difference is not known. The question of the natural reservoir for the oncogenic viruses is discussed. Expression of parts of the early region of the HPV genome in cell lines established from genital cancer supports the hypothesis that papillomaviruses are involved in inducing and/or maintaining the transformed phenotype of cancer cells.

Adenocarcinoma↗
PubMed1986

Different human cervical carcinoma cell lines show similar transcription patterns of human papillomavirus type 18 early genes.

Transcription of human papillomavirus type 18 (HPV18) DNA in the human cervical carcinoma cell lines HeLa, C4-1 and SW756 was studied by nucleotide sequence analysis of HPV18-positive cDNA clones isolated from a HeLa, C4-1 and SW756 cDNA library, respectively, and the cDNA sequences were used to predict the potential encoded proteins. The cDNA clones from all three cell lines were found to be derived from virus-cell fusion transcripts in which 3'-terminal host cell sequences (different for each cell line) were spliced to 5'-terminal exon sequences from the HPV18 E6-E7-E1 region. Three different types of cDNA clones can be distinguished according to the splicing patterns observed in the 5' terminal HPV18 sequences. They carry as potential protein-coding regions the HPV18 specific open reading frames E6 and E6* (generated by splicing and identical with E6 up to the E6* splice junction), E7 and E1 (only in HeLa). Translation of specific cellular genes from the chimeric viral-cellular transcripts seems to be unlikely. The mapping of the 5'-ends of the virus-cell fusion transcripts indicates that transcription is initiated at a viral promoter. The similar patterns of HPV18 transcription in the three different cervical carcinoma cell lines suggest a functional role of HPV18 early genes for the malignant phenotype of these cells.

Amino Acid Sequence↗
PubMed1986

The nucleotide sequence and genome organization of human papilloma virus type 11.

The complete nucleotide sequence of human papilloma virus type 11 (HPV11) DNA (7931 bp) was determined. HPV11 DNA which has been isolated from laryngeal papillomas and from genital warts (condylomata acuminata) shows a high degree of sequence homology to HPV6b (82%). The arrangement of open reading frames is very similar to HPV6b, the homology of the deduced amino acid sequences varies between 58 and 92%. Characteristic features of the noncoding region between the L1 and E6 open reading frames is an AT-rich domain of about 200 bp with extended stretches of alternating thymine-purine bases and a 12-bp inverted repeat element ACCG NNNN CGGT arranged in tandem upstream of the putative early promoter TATA box.

Amino Acid Sequence↗
PubMed1986

[Diagnosis of (intra)-cystic breast cancer].

Besides the known intracystic carcinoma of the breast there are also other cystic tumour types such as, for example, the cystically necrotized carcinoma of the mamma. Preoperative diagnosis of these tumours is effected via pneumocystography and aspiration cytology if mammography alone does not yet permit a definitive assessment of the tumour status. If sonography is used as the only additional examination, diagnostic errors are likely to happen. The well-known recommendation according to which sonographically identified ("simple") cysts can be left as they are, deserves further discussion under this aspect. The problems associated with histological classification and preoperative diagnosis are discussed taking five cystic carcinomas of the breast as basis.

Adult↗
PubMed1985

Cloning and expression of Klebsiella pneumoniae genes coding for citrate transport and fermentation.

Three Escherichia coli clones (DH1/Cit1, DH1/Cit2 and DH1/Cit3) capable of utilizing citrate as a sole carbon source were isolated from a cosmid bank of Klebsiella pneumoniae wild-type DNA. Two of these clones (DH1/Cit1 and DH1/Cit2) only grew aerobically on citrate minimal medium, the third clone (DH1/Cit3) could also be cultured under fermentative conditions. The aerobic as well as the anaerobic generation times of the three clones were from 4.5 to 7 h. Whereas clone DH1/Cit3 showed a pronounced lag phase on citrate when the cells were pre-grown in medium without citrate, clone DH1/Cit1 immediately started growth, while with clone DH1/Cit2 a short lag phase could be observed upon transfer to citrate minimal medium. Restriction analyses of the three plasmids showed that no common fragments had been cloned. The length of the inserts were 13 and 6 kb for the aerobic Cit+ clones and 27 kb (10 kb) for the anaerobic one. Cultures of the anaerobic Cit+ clone were analyzed by immunoblotting techniques and shown to contain oxaloacetate decarboxylase, which confers citrate utilization under anaerobic conditions to K. pneumoniae. Enzyme assays demonstrated the active state of this biotin-containing membrane protein. The specific activity in vesicle preparations from the E. coli clone was 30% of the wild-type K. pneumoniae vesicles. Citrate acts as an inducer of enzyme protein synthesis in the E. coli clone as it does in K. pneumoniae.

Biological Transport↗
PubMed1985

Dental programmes for children and young adults in Denmark in a social perspective.

This report describes the development in dental health in the children and young adult population in Denmark. Based on national as well as selected survey epidemiological data, the improvement in the dental caries situation is illustrated. Over a decade a reduction of about 50% in dental caries prevalence has been registered in children. In young adults caries prevalence has been reduced and participation in regular dental care has increased significantly. The effects of the organized dental programmes on different social groups are illustrated pointing to modifications in the social inequities in the dental services. Longitudinal studies will be needed to prove positive long term effects on adult dental health, which is considered to be the ultimate goal of the programmes.

Adolescent↗
PubMed1985

[Subcutaneous emphysema in status asthmaticus].

Spontaneous subcutaneous accumulations of air in the soft parts of the thorax during an asthmatic crisis (status asthmaticus) are rarely seen. The pathomechanism of the phenomenon, which may lead to the formation of an emphysema of the soft parts via the pneumomediastinum, is discussed, and the possible complications which must be taken into account are pointed out. The value of radiological examination of the thorax in children suffering from asthma bronchiale, is explained briefly.

Adolescent↗