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Biomedical subjects

H Ernst

Publications and source records attributed to H Ernst.

At least 127 records · Page 7Linked to original sources
PubMed1986

Undifferentiated sarcomas induced in Syrian hamsters by subcutaneous injection of diethylstilbestrol.

The carcinogenic effects of weekly subcutaneous injections of dimethylnitrosamine (NDMA: 0.05 of the LD50) and diethylstilbestrol (DES: 1.5 mg/kg body wt) or a combination of both carcinogens were studied in 64 Syrian hamsters. There was no additional tumorigenic effect on NDMA-induced liver tumours in hamsters which received DES treatment prior to NDMA treatment. In contrast to the previously reported DES effects, 72% of the DES-treated hamsters unexpectedly developed undifferentiated sarcomas around the interscapular injection site. This finding suggests a local carcinogenicity of DES, which might not be related to its hormonal effects.

Animals↗
PubMed1986

[Fractionated afterloading irradiation as a new procedure for treating inoperable brain tumors].

A method is shown for fractionated afterloading therapy of inoperable cerebral tumors. A 3 mm thick, tube-form applicator of noble metal which is closed at the front side is implanted into the tumor by a stereotaxic technique and firmly screwed together with the osseous calotte. It remains there up to two weeks, giving full mobility to the patient. The afterloading therapy with a moving iridium source is performed one or two times per day with individual doses of 2 Gray. Thus, the chronological and--to a certain extent--also the spatial dose distribution is variable when applying this method.

Brachytherapy↗
PubMed1986

[Radiotherapy of urinary bladder cancers].

Stagnation in the therapeutic results obtained in treating bladder carcinomas and the very similar results of all treatment methods show that essentially it is not the primary treatment but the stage and biological potency of the tumor that determines the course of the disease. From a radio-oncological viewpoint, it therefore seems appropriate to suggest a treatment concept based on these prognostic criteria, which is adjusted according to the possible therapeutic benefit. The value of radiotherapy as an alternative to cystectomy or as a combination procedure with radical surgical interventions is discussed on the basis of the current literature and our own treatment results.

Combined Modality Therapy↗
PubMed1985

Long-term survival and recurrence-free interval in combined surgical, radio- and chemotherapy of malignant brain gliomas.

A prospective randomized study has been conducted since 1978 to judge the value of combined radio- and chemotherapy (CCNU) in the postoperative treatment of grade III and IV supratentorial gliomas. Inoperable or recurrent tumors were excluded from these series, but evaluated in addition. Increase in median survival time (18 months) for the entire series (62.2% glioblastomas) was only small compared to other series mentioned in literature, but there was a significant prolongation of the recurrence-free interval (16.5 months) and in the total survival time from the onset of symptoms in 46.4% of cases living more than 18 months. If 'useful recovery' is the major goal of present treatment of cancer, the recurrence-free interval and the fraction of long-term survivors may be more important statistical parameters than median survival time. To improve the 'quality of life' in a number of patients (so-called long-term survivors) and the length of recurrence-free intervals should be the therapeutic goal, even if overall survival time remains essentially unaffected. We conclude that combined therapy, including radio- and chemotherapy, following surgical resection is of value in most cases of malignant glioma.

Adolescent↗
PubMed1985

Reovirus hemagglutinin mRNA codes for two polypeptides in overlapping reading frames.

Human reovirus s1 mRNA, which codes for the viral hemagglutinin, also directs the synthesis of a previously unrecognized polypeptide of molecular mass 14 kDa in reticulocyte and wheat germ extracts. Hybrid-arrest of translation by selected restriction fragments of cloned S1 DNA indicated that synthesis of the 14-kDa polypeptide initiates at the second AUG. This was confirmed by NH2-terminal sequence analyses. The coding sequence for the 14-kDa polypeptide thus lies entirely within the hemagglutinin gene but in a different reading frame. Although not found in virions, the 14-kDa polypeptide apparently is formed in virus-infected mouse L cells, as demonstrated by comparison of [35S]methionine-labeled polypeptides in cell extracts with the corresponding in vitro products.

Amino Acid Sequence↗
PubMed1984

Two initiation sites detected in the small s1 species of reovirus mRNA by dipeptide synthesis in vitro.

Reovirus mRNAs directed the synthesis of fMet dipeptides in a translation initiation system reconstituted from rabbit reticulocyte initiation and elongation factors, Artemia salina 80S ribosomes, yeast fMet-tRNAiMet and Escherichia coli3H-labeled aminoacyl tRNAs. As predicted from the GC(U,G) codon that follows the 5'-proximal AUG in half of the viral mRNA species, fMet-Ala was the predominant dipeptide product obtained in response to a mixture of mRNAs or to the separated size classes of medium (m) and small (s) mRNA. The four individual small mRNA species each directed the synthesis of an fMet dipeptide that was consistent with the utilization of the 5'-proximal AUG for initiation. In addition to fMet-Asp, the s1 mRNA also directed fMet-Glu synthesis indicative of initiation in a second reading frame at the 5'-penultimate AUG. The tripeptide fMet-Glu-Tyr was also synthesized from s1 mRNA, which further verified this second initiation site. mRNAs containing 5'-terminal GpppG were 10-15% as active as the corresponding m7G-capped templates. The dipeptide assay provides a rapid method for determining initiation sites in individual mRNAs or in mixtures of mRNAs.

Amino Acid Sequence↗
PubMed1983

The primary structure of initiation factor IF3 from Bacillus stearothermophilus.

The complete amino acid sequence of the initiation factor IF3 from Bacillus stearothermophilus has been elucidated. This was achieved by splitting the protein with trypsin, Staphylococcus protease or cyanogen bromide. The amino acid sequence was determined by manual Edman degradation, using the DABITC/PITC double-coupling method. The IF3 molecule contains 171 amino acids and has an Mr of 19 677. The sequence was compared to the homologous molecule from Escherichia coli; about 50% of the amino acid residues were found to be identical.

Amino Acid Sequence↗
PubMed1983

Initiation by RNA polymerase II and formation of runoff transcripts containing unblocked and unmethylated 5' termini.

Transcription of cloned adenovirus, beta-globin, and retrovirus long terminal repeat DNAs in HeLa whole-cell lysate was inhibited by S-adenosylhomocysteine. However, full-length 1.7-kilobase transcripts made on adenovirus 2 late promoter DNA contained 5'-terminal GpppA, consistent with specific initiation and runoff synthesis in the absence of product methylation. Formation of runoff transcripts including retrovirus RNAs that normally contain 5'-m7GpppGmpC was not decreased by replacing GTP with non-hydrolyzable analogs, and Rous-associated virus-2 runoff products made in the presence of GTP-gamma-S contained 5'-terminal gamma-S-pppGpC. The results indicate that capping and specific transcript synthesis by RNA polymerase II are not obligatorily linked in HeLa whole-cell lysate. Accurate initiation is dependent on ATP hydrolysis, and in contrast to GTP, replacement of ATP by 5'-adenylyl-imidodiphosphate blocked specific initiation of transcripts that start with either GTP (Rous-associated virus-2, Rous-associated virus-0) or ATP (beta-globin, adenovirus).

Adenoviruses, Human↗
PubMed1982

Species specificity of promoter recognition by RNA polymerase and its transfer by the sigma factor.

RNA polymerase holoenzyme from Micrococcus luteus synthesizes in vitro a run-off transcript of 85 nucleotides from a DNA fragment containing part of gene E of bacteriophage phi X174. This RNA starts with GTP as the 5' terminus 18 nucleotides downstream from the start of gene E on the viral (+)strand. Transcription does not occur when the fragment is cleaved 36 nucleotides upstream of the initiation site. No transcript is obtained with RNA polymerase core or holoenzyme from Escherichia coli. Other DNA fragments containing the three major E. coli promoters of phi X174 are transcribed by both enzymes although much less efficiently by M. luteus RNA polymerase. When subunit sigma in E. coli RNA polymerase is replaced by sigma from M. luteus the resulting hybrid enzyme actively transcribes the DNA fragment containing the inner region of gene D with formation of the same run-off transcript which is obtained with M. luteus holoenzyme. In the presence of sigma from E. coli this RNA is not synthesized. The hybrid enzyme also transcribes a DNA fragment containing the gene A promoter of phi X174 with even higher efficiency than RNA polymerase holoenzyme from E. coli.

Bacillus subtilis↗
PubMed1981

[Metastasis to the lymph nodes from an occult primary tumor: aspects of diagnostics and therapy (author's transl)].

Sixty-one patients with lymph node metastases and occult primary tumor are reported. The patients were analyzed with respect to age and sex, as well as to the histologic diagnosis of the lymph nodes examined. In 24 of these patients, the primary tumor was found later; in 12 of these, not until autopsy. Site and histologic type of the lymph node metastases permit conclusions about the primary tumor. Treatment of the metastasis by surgery or irradiation ist indicated in order to hinder expansion and, in cases of late discovery of primary tumor, to take advantage of the remaining chances for a cure. The prognosis is unfavorable when the primary tumor remains undiscovered. In our patient group, the average survival time following confirmation of a lymph node metastasis was only 25 months. Lymph node metastases in the neck region are a special case. Here, the occult primary tumor ist sometimes cured in connection with surgery and/or irradiation of the cervical region.

Adult↗
PubMed1980

[Radiological diagnosis and therapy of chest pain (author's transl)].

The causes and localization of chest pain are numerous. They can derive from infections, traumas, or tumors. Possible sites of origin are: skeletal portions vertebral column, ribs, and sternum, as well as mediastinum and pleura. In women, occurrence tends to be cyclic and affect the mamma region. Radiological diagnosis includes radiography, nuclear techniques as well as whole body computer-tomography. Radiation therapy is indicated in cases of mediastinal tumor formation. Radiation of painful osteolytic vertebral metastases and rib destructions proves to be an efficient palliative measure.

Bone Neoplasms↗