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Biomedical subjects

F Weber

Publications and source records attributed to F Weber.

At least 235 records · Page 13Linked to original sources
PubMed1986

An ultrasonographic study of the organisation of sucking and swallowing by newborn infants.

Healthy infants' sucking, swallowing and breathing movements were observed ultrasonographically during breast- and bottle-feeding between two and five days after birth. Sucks were found to occur either on their own or in combination with a swallow. Swallows did not occur on their own. Younger babies' swallowing invariably was associated with a pause in breathing. Older babies generally showed better co-ordination of sucking, swallowing and breathing than younger ones, whether breast- or bottle-feeding.

Bottle Feeding↗
PubMed1986

[Quality assurance in general surgery by prospective patient documentation. A comparison over 5 years].

All patients who had undergone general surgery in three different periods of time were prospectively recorded. Results were found to have been improving with significance owing to peri-operative antibiotic prophylaxis, mechanical suturing (for gastro-intestinal anastomoses), and introduction of a system of regular documentation. Rates of postoperative complications were also affected by the individual surgeon's efficiency and techniques.

Anti-Bacterial Agents↗
PubMed1986

[Methodological and experimental studies of jet ventilation--indications and limits of the procedure].

Results of experimental and methodical investigations of so-called "Injector-Ventilation" or jet ventilation verify procedures' safety regarding ventilation and anaesthesia management. Classification of jet ventilation permits delimitation to IPPV and different methods of HFV. Resulting from considerations, especially based on reported insignificancy of "Venturi-Effect" under clinical conditions, authors suggest use of unitary term "Normo-Frequent Jet Ventilation" (NFJV).

Anesthesia, Inhalation↗
PubMed1986

[Normofrequent jet ventilation (N20/02 mixture). I. Anesthesiologic principles and experiences using the jet ventilation method].

Report on normo-frequent jet ventilation using N2O/O2 mixture for endolaryngeal and tracheal diagnostic and surgical procedures. Presentation of a system of flexible and rigid sounds. Choice of sounds and driving pressures permits adaptation to different physiological and pathological conditions. Possible methodical complications and their prophylaxis are pointed out. Cardiac arrhythmias occur caused by manipulations only and independent of jet ventilation. Therefore authors recommend continuous ECG monitoring during endolaryngeal manipulations under general anaesthesia too.

Anesthesia, Inhalation↗
PubMed1986

[Critical evaluation of jet ventilation from the viewpoint of the endoscopist].

Endoscopists' clinical experiences using jet ventilation (N2O/O2 mixture) for microlaryngoscopy, endolaryngeal microsurgery and tracheobronchoscopy of adults, children and (small) infants are advantageous. Especially authors accentuate: Improved clearness of laryngeal area; overcoming intubation obstacles; extraordinary variability of sounds' arrangement. Authors observed no complications caused by this method. A "symptom of absent sharpness" (microscope) refers to dignity of epithelial alterations at vocal cords. The hygienic molestation of endoscopist by gas backflow is disadvantageous; on the other hand the same backflow essentially excludes a potentially risk of aspiration.

Adult↗
PubMed1985

Enhancer activity correlates with the oncogenic potential of avian retroviruses.

Avian retroviruses lacking an oncogene, such as Rous-associated virus 1 (RAV-1), RAV-2, and td mutants of Rous sarcoma virus (RSV), can nevertheless cause leukemias and other neoplastic diseases. During this process, viral DNA integrates near a cellular proto-oncogene, such as c-myc, and thus de-regulates its expression. The virus RAV-0, on the other hand, is known to be non-oncogenic even in long-term in vivo infections of domestic chickens. The major difference between oncogenic and non-oncogenic viruses is found within the U3 region of the long terminal repeat (LTR) which is known to harbor the promoter and enhancer elements. We therefore wanted to see whether viral oncogenicity was correlated with enhancer activity. Using a variety of techniques (including the SV40 'enhancer trap' from which we obtained RSV-SV40 recombinant viruses), we demonstrate that a strong enhancer exists within the LTRs of both RSV and RAV-1. In contrast, no enhancer is present in RAV-0, although RAV-0 has functional promoter elements. Our data therefore strongly support a concept of oncogenesis by enhancer insertion.

Animals↗
PubMed1985

A transcription enhancer in the Herpesvirus saimiri genome.

Herpesvirus saimiri, an oncogenic agent of New World primates, has a linear double-stranded DNA genome of approximately 155 kb. To test its genome for the presence of a transcription enhancer, we have mixed randomly fragmented H. saimiri DNA with non-infectious, linear SV40 DNA lacking the 72-bp repeat enhancer region (the so-called SV40 enhancer trap) and co-transfected this DNA mixture into monkey CV-1 cells. Viable SV40-like viruses were generated by intracellular ligation/repair processes with short H. saimiri DNA fragments. One recombinant, SVHS-2, had integrated a 377-bp enhancer segment from the righthand region of the H. saimiri genome, 7 kb upstream of DNA sequences encoding an immediate-early mRNA. This enhancer sequence is contained within the non-repetitive portions of the viral genome known to be preserved episomally in all lymphoid tumor cell lines. Further recombinant viruses (SVHS-14, SVHS-7, and SVHS-8) essentially contain subsets of the 377-bp insert. Unlike in the previous enhancer trap experiments, where heterologous enhancers were incorporated without any sequence alterations, SVHS-14 and SVHS-7 have suffered short internal deletions of a very similar segment of the H. saimiri insert. This renders the enhancer more active, implying that the deleted segment, while it may have a role in the herpesvirus infection cycle, exerts a negative effect within the isolated enhancer.

Antigens, Viral, Tumor↗
PubMed1985

Beta-adrenoceptor subtype of the venous capacity system: characterization by venous occlusion plethysmography.

In order to characterize the beta-adrenoceptor subtype of the venous vessel wall, venous occlusion plethysmograph studies were carried out in 7 healthy volunteers. Venous distensibility (VD) was considered to be a measure of venous tone. Infusion of the beta 1- and beta 2-adrenoceptor agonist isoproterenol (I), of the predominantly beta 2-adrenoceptor agonist fenoterol (F) and of the predominantly beta 1-adrenoceptor agonist dobutamine (D) in increasing doses led to a significant increase in VD by I and F but not by D. Administration of the beta 1-adrenoceptor antagonists betaxolol (B) and metoprolol (M) did not significantly change VD. Neither beta-adrenoceptor antagonist prevented the increase in VD provoked by subsequent administration of I or F. It is concluded that beta-adrenoceptors in the venous vessel wall belong to the beta 2-adrenoceptor subtype.

Adrenergic beta-Agonists↗
PubMed1985

High frequency of homologous recombination in mammalian cells between endogenous and introduced SV40 genomes.

We have detected a high frequency of homologous recombination between introduced and chromosomal DNA in mammalian cells. Linear enhancerless SV40 DNA has been transfected into monkey cells that have either one (COS1 cells) or five to seven (COS7 cells) copies of the SV40 early region stably integrated into their genome. Enhancer-containing wild-type SV40 DNA is formed as a result of homologous recombination of the introduced DNA with chromosomal DNA. Up to 25% of the successfully transfected cells produce wild-type virus within 48 hr after transfection. The highest levels of wild-type virus were produced from transfections of molecules that contained a double-strand break at positions of uninterrupted homology with the chromosomal template. This SV40/COS cell system provides a rapid assay for recombination between introduced and genomic DNA.

Animals↗
PubMed1985

A very strong enhancer is located upstream of an immediate early gene of human cytomegalovirus.

A strong transcription enhancer was identified in the genomic DNA (235 kb) of human cytomegalovirus (HCMV), a ubiquitous and severe pathogen of the herpesvirus group. Cotransfection of enhancerless SV40 DNA with randomly fragmented HCMV DNA yielded two SV40-HCMV recombinant viruses that had incorporated overlapping segments of HCMV DNA to substitute for the missing SV40 enhancer. Within HCMV, these enhancer sequences are located upstream of the transcription initiation site of the major immediate-early gene, between nucleotides -118 and -524. Deletion studies with the HCMV enhancer, which harbors a variety of repeated sequence motifs, show that different subsets of this enhancer can substitute for the SV40 enhancer. The HCMV enhancer, which seems to have little cell type or species preference, is severalfold more active than the SV40 enhancer. It is the strongest enhancer we have analyzed so far, a property that makes it a useful component of eukaryotic expression vectors.

Base Sequence↗
PubMed1985

A long and complex enhancer activates transcription of the gene coding for the highly abundant immediate early mRNA in murine cytomegalovirus.

Using the simian virus 40 "enhancer trap" approach, we have identified a transcription enhancer located just upstream of the major immediate early gene of murine cytomegalovirus. This enhancer has several striking properties. (i) Together with the enhancer of human cytomegalovirus, it is the strongest transcription enhancer found to date. (ii) It is an extremely long enhancer, spanning greater than 700 base pairs. (iii) It consists of a rather complex pattern of sequence repeats, the longest of which is 181 base pairs. Also, several types of short sequence motifs are scattered throughout the enhancer in monomeric, heterodimeric, or homodimeric (palindromic) form. These motifs have been identified to be components of other enhancers and promoters, and they are presumably binding sites for specific nuclear factors. Our analysis suggests that enhancers are composed of a modular arrangement of short conserved sequence motifs and that enhancer strength is correlated with the redundancy of these motifs.

Animals↗
PubMed1985

[Experiences with 2 years of quality control following general and vascular surgery in 3193 patients].

3193 general and vascular surgical interventions were prospectively controlled regarding the postoperative complication rates. The examination of all complication data was necessary to define the risk of the various operations. By a regular follow-up system the risk of wound infections and other complications decreased. Although perioperative antibiotic prophylaxis and stapling devices for gastrointestinal end-to-end anastomoses were routinely used, the surgeon still influenced the complication rates.

Arteries↗
PubMed1985

[Comparison of the measurement accuracy of electronic blood pressure self measurement devices 1980-1983].

The accuracy of 21 new electronic devices designed for self-measurement of blood pressure has been tested on an average of 22-24 subjects each by simultaneous measurements on the same arm. Compared with electronic devices made in 1980 the accuracy has improved, especially with regard to the estimation of diastolic blood pressure. Nevertheless, most devices still give too low a value for diastolic blood pressure. In agreement with former results the systolic differences are greater in women and in normotensive subjects, whereas the diastolic differences are more pronounced in younger subjects, in males and in hypertensive patients. Despite the differences due to different sites of auscultation, the results of the best devices tested show that electronic devices may estimate the same blood pressure values over the brachial artery as measured by auscultation in the antecubital fossa. We therefore suggest stronger regulations for the licensing of new electronic devices.

Blood Pressure↗
PubMed1984

Phytohemagglutinin-induced diarrheal disease.

A purified plant lectin, phytohemagglutinin (PHA), or crude red kidney bean (RKB) from which it was derived, when incorporated as 1% of dietary protein into a purified casein protein diet caused weanling rats to fail to grow or lose weight in comparison to control animals pair fed an isonitrogenous, isocaloric diet. Feeding PHA was observed to cause diarrhea: fecal wet and dry weights were increased within 2 days after starting the diet. Increased fecal weight was caused by increased dry weight as well as by an increased fecal water content. On reversion to a normal casein diet, rapid amelioration of the antinutritional effects of PHA occurred with resumption of normal growth rate. Specific binding of PHA to the microvillus region of the small intestinal epithelium was demonstrated using rabbit anti-PHA and fluorescein-labeled goat anti-rabbit immunoglobin. PHA binding was observed after chronic intake in the diet or when applied to normal tissue in vitro. Loss of PHA binding to the intestine was observed to occur within 48 hr on reversion to a control casein diet. No significant morphological damage to the microvilli or the mucosal villus architecture was observed to accompany PHA adherence under these experimental conditions. Antinutritional and antiabsorptive effects of dietary PHA were associated with diarrhea. PHA adhered to the microvillus membrane of the small intestinal villus surface during the diarrheal state.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

An SV40 "enhancer trap" incorporates exogenous enhancers or generates enhancers from its own sequences.

We have transfected monkey CV-1 cells with non-infectious, linear SV40 DNA, lacking the 72 bp repeat enhancer region. Infectious virus was recovered from this "enhancer trap" upon cotransfection with enhancer DNA segments from various viruses, notably a truncated polyoma enhancer that was integrated as a dimer. Cotransfection of the "enhancer trap" with fragmented DNA of mouse, monkey, or human origin yielded no recombinant virus with integrated cellular sequences, with one possible exception. In some transfection experiments without added viral enhancer DNA, SV40 variants were generated that have a segment of their flanking "late" DNA duplicated to substitute for the deleted 72 bp repeat. In one variant, an 88 bp duplication creates a strong enhancer from this nonenhancing DNA region. Both the polyoma enhancer fragment and the spontaneously created enhancers lack the alternating purines-pyrimidines or "CACA box" suggested to be characteristic for enhancer elements and show only limited homology to the "GTGG(AAATTT)G box."

Animals↗