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Biomedical subjects

G Sauer

Publications and source records attributed to G Sauer.

At least 55 records · Page 3Linked to original sources

[Treatment of open tibial fracture with fixateur externe].

External fixation with a Hoffmann or an ASIF frame was used in the treatment of 50 severe open lower leg fractures from 1979 to 1987. In 7 cases consolidation was achieved by means of external fixation without changing to any other method. Plaster cast fixation was subsequently performed after soft-tissue healing in 35 patients. Further methods of treatment applied after external fixation were intramedullary nailing in 5 cases, internal stabilization with a plate in 1 case and provision of a surgical support in 1 case. In 1 patient early amputation was necessary. On average, fracture healing took 6.7 (4-15) months, significantly correlating with the severity of soft-tissue lesion. Compound fractures of the proximal tibial shaft turned out to be problem cases, requiring up to 15 months for bone union. Acute infections occurred in 6 cases (12%), despite primary antibiotic prophylaxis. Nonunion was noted in 2 patients. A follow-up examination of 33 patients after a median of 45 months (range 6-99) showed full weight-bearing in all cases. Persistent soft-tissue problems were found in 7 patients, chronic osteitis in 4, and shortening of the extremity by up to 2 cm in 11 cases. One-third of the patients were out of work or had had to change their jobs as a social effect of their severe injuries.

Adolescent↗

[Chronic fibular ligament insufficiency at the upper ankle joint. Late results after modified Watson-Jones plastic surgery].

The findings at clinical and roentgenological follow-up examination of 44 patients are reported to illustrate the long-term results of a modified Watson-Jones technique up to 90 months after the operation. The clinical results (86.3% of the patients without complaints and 88.6% with subjective stability of the ligaments) correspond with those given by a variety of sources in the literature. The roentgenological examination, on the other hand, showed signs of grade I or II arthrosis (Bargon scale) in 61.3% of cases, and arthrosis was worse than before the operation in nearly all cases. The patients in the group, that had received more conservative treatment with an average 6.3 years between lesion and surgical treatment (group 1), had the highest incidence of arthrosis, with 73.6%. In 10 cases the clinical examination revealed reduced supination and dorsiflexion attributable to the tenodesis effect associated with the Watson-Jones technique. In view of the high rate of arthrosis, younger patients and patients with a short tendon part of the peroneus brevis muscle should be treated by another, more "physiological" method.

Adolescent↗

The extraction of high-molecular-mass DNA from hair shafts.

A simple and efficient method is presented for the extraction of DNA from hair shafts. DNA preparations obtained by this approach can be made amenable to restriction enzyme digestion, thereby allowing further molecular biological analysis.

Centrifugation↗

Interruption of growth signal transduction by an antiviral and antitumoral xanthate compound.

The binding of growth factors to the cellular receptors elicits the phosphorylation of proteins which transmit growth signals to the nucleus [E. Rozengurt (1986) Science 234, 161-166]. Both the tyrosine-specific kinase (growth factor receptor) and the threonine-serine phosphorylating protein kinase C (pkC) become activated upon binding of the epidermal growth factor (EGF) to its receptor. Here we describe the selective inhibition of the pkC activation by tricyclodecane-9-yl-xanthogenate (D609) in the presence of unsuppressed receptor tyrosine autophosphorylation. As a consequence the affinity of EGF to the receptor was not down-regulated and the complex failed to be internalized.

Animals↗

Inhibition of HIV-1 replication by an antiviral xanthate compound in vitro.

The antiviral xanthate compound tricyclodecan-9-yl-xanthogenate (code name D609) is capable of inhibiting DNA and RNA viruses in vitro. It can also inhibit the shedding of infectious HIV into the tissue culture medium from chronically infected lymphoma cells (KE37-III) as shown by infectivity assays and Western blots of the supernatant. HIV-specific proteins, however, were accumulated intracellularly. The initiation of a de novo HIV replication after infection of permissive KE37-1 cells was completely inhibited at concentrations of D609 which still permitted mitotic divisions of the cells. Furthermore, the selective antiviral activity of the xanthate compound was evidenced by the absence of HIV replicative intermediate DNA. The expression of cellular genes, such as c-myc, remained unimpaired within these cells.

Antiviral Agents↗

Physical state and biological activity of human papillomavirus genomes in precancerous lesions of the female genital tract.

The DNA of distinct human papillomaviruses (HPVs) is regularly detected in the majority of human cervical carcinomas. In contrast to benign HPV-induced genital lesions, where the viral genomes are exclusively present as episomes, in cervical carcinomas HPV type 16 (HPV16) DNA was found to be integrated into the host DNA. In order to determine the physical state and expression of HPV DNA sequences at different stages of tumour development, we analysed a series of cervical lesions (mild, moderate and severe dysplasia and carcinoma in situ) that are considered precursors of carcinomas of the cervix. In 66.6% (18 of 27) of the tumours, HPV16 DNA was present. While in mild dysplasias only episomal HPV genomes were found, in all higher grade lesions integration of the viral DNA was detected. There was a close correlation between the episomal state and the expression of the HPV16 genomes: in 15 cases harbouring episomal HPV16 DNA (seven of which also contained integrated genomes) viral transcripts were present. We conclude that integration of HPV genomes takes place very early in cervical cancer development. In addition, the episomal state of the viral DNA depends on viral gene expression. The same conclusion, however, is not applicable in those lesions (three severe dysplasias) containing exclusively integrated HPV16 DNA. Thus, HPV16 DNA can persist in an integrated state without recognizable transcriptional activity. These results point to HPV16 as one potential prerequisite for the first steps in the multistage development of human cervical cancer.

Carcinoma in Situ↗

[A new technic for arthroscopic reinsertion and augmentation of the recently torn anterior cruciate ligament].

The arthroscopic examination of every recent haemarthrosis of the knee, even in cases without clinically obvious instability has increased the number of primary diagnosed ruptures of the LCA in the last years. The most frequent lesion of the LCA was the proximal rupture. The usual methods for the operative treatment of the ruptured LCA require the opening of the knee joint and cause the weakening of hamstrings, with all disadvantages connected with these procedures. Basing on the experiences in arthroscopic surgery of meniscal lesions and the good results of alloplastic augmentation an new method of arthroscopic refixation and augmentation of the torn LCA has been developed. The use of an arthroscopic meniscal stitcher enables anatomically exact reconstruction of the torn ligament through a femoral tunnel. Augmentation by an LAD-band (Kennedy) or Trevira band (Hoechst) allows postoperative functional treatment, avoiding atrophic degeneration of muscles and loss of mobility by immobilisation. Postoperative pain is reduced to a minimum compared to conventional technics. The period of rehabilitation is considerably shortened.

Arthroscopes↗

Synergistic antiviral effect of xanthates and ionic detergents.

Xanthate compounds have been shown to exhibit antiviral activity against various DNA and RNA viruses under acidic pH conditions. It is now possible to utilize the unique broad range antiviral spectrum of these compounds under physiological pH conditions (pH 7.4) by simultaneous administration of certain ionic detergents. When used in conjunction with tricyclodecan-9-yl-xanthate (D609), sodium deoxycholate, sodium dodecylsulfate and certain fatty acids, which have no antiviral activity of their own, inhibit the replication of various DNA and RNA viruses (such as herpes simplex, vesicular stomatitis and Coxsackie B 4) in vitro at pH 7.4. Among saturated fatty acids of various chain lengths there was a marked size restriction in that the efficiency of undecanoic acid (11 C atoms) was three orders of magnitude greater than that of shorter (6 C atoms) or longer (18 C atoms) monocarbonic acids. Dose-response kinetics revealed a synergistic interaction between the xanthate and the monocarbonic acid. A dose that inhibited the replication of herpesvirus by a factor of 1000 still permitted mitotic activity in uninfected growing control cultures.

Animals↗

Selective killing of tumor cells by xanthates.

Xanthate derivatives of primary alcohols with antiviral properties exert, in combination with monocarboxylic C11 or C12 acids a pronounced anti-tumor activity in vitro and in vivo. Tricyclodecan-9-yl-xanthogenate (D609) or cyclododecyl xanthogenate (D435) when administered together with either undecanoic or dodecanoic acid to various transformed animal and human tumor cells (displaying low serum requirement) cause cell death. In contrast, normal cells from which transformed derivatives arose, were unaffected.

Animals↗

Inhibition of the phosphorylation of the regulatory non-structural protein of vesicular stomatitis virus by an antiviral xanthate compound.

The growth of vesicular stomatitis virus (VSV) can be inhibited by the antiviral compound tricyclo-decane-9-yl-xanthogenate (D609). On analysing the antiviral mechanism we found no effect on the primary transcription of infecting VSV genomes. In contrast, the processes of replication and transcription during late stages of infection were inhibited. Despite the synthesis of all five virus-coded proteins (41% to 56% of the uninhibited control), as shown by labelling with [35S]methionine, the phosphorylation of the non-structural (NS) protein was reduced in the presence of the xanthate by a factor of at least 17. The pattern of phosphorylation of the bulk of cellular proteins remained unaltered under the same conditions. A relation between a possible loss of biological activity of the NS protein owing to the lack of phosphorylation and the decreased VSV RNA synthesis is suggested.

Antiviral Agents↗

[Acute coronary angiography in therapy-refractory angina pectoris].

UNLABELLED: Emergency coronary angiography was performed in 188 patients with treatment-resistant unstable angina. Criteria analysed were: duration of angina less than 72 h; angina despite heparin and nitroglycerin infusion; no significant S-T segment elevation in the ECG; creatine-kinase rise up to 150 U/l. Coronary heart disease (CHD) was found in 130 patients (group A). In 47 of them a recent coronary occlusion was demonstrated angiographically (main stem: 1; anterior interventricular branch: 8; circumflex branch: 27; right coronary artery: 11 patients). An at least 90% occlusion of one coronary artery was found in 58 patients. A 75% stenosis of several vessels was found in 25 patients making it impossible to identify the vessel that had caused the angina. A bypass operation was performed in 62 patients within two weeks. During the acute coronary angiography, intracoronary streptokinase infusion was performed in 11 (success rate 55%), percutaneous transluminal coronary angioplasty in 26 (success rate 88%). In 58 patients (group B) CHD was excluded. The final diagnosis in these was: mitral valve prolapse (31); pericarditis (6), dilated cardiomyopathy (3); coronary anomaly (3); muscle bridge in the anterior interventricular branch (2): normal (13). CONCLUSION: It is not possible to decide with certainty, in the absence of typical infarction signs in the ECG and clinically, whether treatment-resistant angina is due to CHD or other causes. Acute coronary angiography is indicated in such cases, because even without S-T segment elevation an acute coronary occlusion is present in 25%, and in 50% of cases an acute therapeutic intervention is indicated.

Adult↗

Properties of intracellular bovine papillomavirus chromatin.

Episomal nucleoprotein complexes of bovine papillomavirus type 1 (BPV-1) in transformed cells were exposed to DNase I treatment to localize hypersensitive regions. Such regions, which are indicative for gene expression, were found within the noncoding part of the genome, coinciding with the origin of replication and the 5' ends of most of the early mRNAs. However, there were also regions of hypersensitivity within the structural genes. These intragenic perturbations of the chromatin structure coincide with regulatory sequences at the DNA level. One of these regions maps in close proximity to a Z-DNA antibody-binding site which is located near the putative BPV-1 enhancer sequence.

Animals↗