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Biomedical subjects

C Meyer

Publications and source records attributed to C Meyer.

At least 415 records · Page 23Linked to original sources
PubMed1990

[Silent myocardial ischemia--risk for sports in coronary groups?].

The present discussion of SMI is of major impact on physical active coronary patients, since SMI during physical training could represent a potential risk factor. We carried out an investigation in 107 coronary patients of ambulant coronary groups (ACG) on the incidence of SMI during exercise testing and Holter monitoring (HM) including a training unit. With both techniques in approximately 1/3 of the patients SMI could be observed, when coronary medication was omitted. However the concordance of these two positive groups was found to be remarkably low. During HM SMI was found within the training units nearly as frequent as during normal daily life. By beta blockade (100 mg metoprolol) exercise SMI during HM was suppressed in 2/3. Our conclusion was that SMI is not of major significance in pharmacologically well controlled participants in ACG.

Adult↗
PubMed1990

A high yield affinity purification method for specific RNA-binding proteins: isolation of the iron regulatory factor from human placenta.

We describe a simple method for the affinity purification of specific RNA-binding proteins. DNA sequences corresponding to the protein-binding site of the RNA are subcloned into an in vitro transcription vector between the T7 viral promoter and a poly(A) track. A polyadenylated RNA transcript is bound to poly(U)-Sepharose and subsequently incubated with a cellular extract prepurified on heparin-agarose. Specifically adsorbed proteins are recovered in high yield and purity from the affinity matrix by high salt elution. Using this method we isolated the iron regulatory factor (IRF), a cytoplasmic protein which binds to specific palindromic elements in the 5' and 3' untranslated sequences of ferritin and transferrin receptor mRNA, respectively. Activation and binding of this regulatory factor correlates with increased transferrin receptor mRNA stability and inhibition of ferritin translation. The purified factor from human placenta migrates as a monomer in gel chromatography, but is present in equimolar amounts of two proteins with molecular weights of 95 and 100 kDa when analysed by SDS/PAGE. The two proteins are highly related as judged by the identity of their isoelectric points and their specificity to form RNA-protein complexes.

Base Sequence↗
PubMed1990

Cloning and nucleotide sequence of the Salmonella typhimurium pepM gene.

The pepM gene coding for a methionine-specific aminopeptidase was cloned from Salmonella typhimurium and its nucleotide sequence determined. The gene encoded a 264 amino acid protein that was homologous to a similar protein from Escherichia coli. The sequence of an overproducer mutant allele, pepM100, contained a single base change in the likely--35 region of the pepM promoter that increased its homology to the consensus promoter sequence. A region downstream from the pepM coding sequence contained extensive inverted repeats and was homologous to sequences found elsewhere in both Salmonella and other bacterial species.

Alleles↗
PubMed1990

Biochemical and Immunological Characterization of Nitrate Reductase Deficient nia Mutants of Nicotiana plumbaginifolia.

Sixty-five Nicotiana plumbaginifolia mutants affected in the nitrate reductase structural gene (nia mutants) have been analyzed and classified. The properties evaluated were: (a) enzyme-linked immunosorbent assay (two-site ELISA) using a monoclonal antibody as coating reagent and (b) presence of partial catalytic activities, namely nitrate reduction with artificial electron donors (reduced methyl viologen, reduced flavin mononucleotide, or reduced bromphenol blue), and cytochrome c (Cyt c) reduction with NADH. Four classes have been defined: 40 mutants fall within class 1 which includes all mutants that have no protein detectable in ELISA and no partial activities; mutants of classes 2 and 3 exhibit an ELISA-detectable nitrate reductase protein and lack either Cyt c reductase activity (class 2: fourteen mutants) or the terminal nitrate reductase activities (class 3: eight mutants) of the enzyme. Three mutants (class 4) are negative in the ELISA test, lack Cyt c reductase activity, and lack or have a very low level of reduced methyl viologen or reduced flavin mononucleotide-nitrate reductase activities; however, they retain the reduced bromphenol blue nitrate reductase activity. Variations in the degrees of terminal nitrate reductase activities among the mutants indicated that the flavin mononucleotide and methyl viologen-dependent activities were linked while the bromphenol blue-dependent activity was independent of the other two. The putative positions of the lesions in the mutant proteins and the nature of structural domains of nitrate reductase involved in each partial activity are discussed.

Journal Article↗
PubMed1990

Detection of Epstein-Barr virus DNA by polymerase chain reaction in lymph node biopsies from patients with angioimmunoblastic lymphadenopathy.

Epstein-Barr virus DNA was detected by the polymerase chain reaction (PCR) in five lymph node biopsies from eight patients with diagnosis of angioimmunoblastic lymphadenopathy (AILD). Three pairs of specific primers detected EBV DNA sequences near the 5' end (Bam W region), the middle (BMRF 1 region) and the 3' end (Eco RI D region) of the viral genome with equal accuracy when 1 microgram of DNA and 30 amplification cycles were used. When only 100 ng of DNA were screened with the BMRF 1 set of primers, a specific amplification product was still identifiable. The 593 base pair amplification product obtained using the Eco RI D set of primers was shown to contain an expected Sma I site at position 215, confirming the viral origin of the amplified sequence [corrected]. Our findings indicate that lymph nodes of AILD patients frequently harbour the entire EBV genome at a high percentage of at least 1 viral copy per 15,000 human cells.

Base Sequence↗
PubMed1990

[To be or not to be].

It's all about life in an intensive care unit. Of course, there is an organic aspect of life, the maintenance of which relies on a knowledge. Playing with a human being, life relies also on a psychological aspect and the temptation is great to answer the problematical by knowledge as well. But such an attitude would be most inoperative. It could only serve the therapeutist in economizing his own psychological engagement in the relation with the patient. In the confrontation between patient and therapeutist, isn't it rather a question of existential work between two protagonists during which the patient would be fighting for the maintenance or the restitution of his own person, while the therapeutist tries to maintain his.

Critical Care↗
PubMed1990

[Criteria for selection and contra-indications of ambulatory surgery].

Ambulatory surgery means to us the scheduled surgery and investigations carried out under various modes of anaesthesia in patients who are admitted in the morning and discharged in the evening. Now the strictness and guarantees required and the essential conditions of safety and efficiency can only be achieved if a number of selection criteria and contraindications are complied with. The authors first study the lesions for which ambulatory treatment is possible, as well as the criteria regarding both the patient and the attending physician responsible for the follow-up at home. Since a close co-operation between the anaesthesist and the surgeon proves to be essential, the criteria of anaesthesia must also be dealt with. The contraindications are connected to the type of surgery, to the type of anaesthesia, to the patient, to the patient's circle, to the medical team, and finally to the equipment and organization of the unit in which ambulatory surgery is performed. These many aspects of the problem are analyzed and discussed.

Ambulatory Surgical Procedures↗
PubMed1990

[Severe acute intestinal hemorrhage. Value of investigation tests].

Episodes of intestinal bleeding likely to endanger vital functions require detailed etiological and topographical examination before surgical intervention. Forty-two cases of serious haemorrhage of the lower digestive system in adults were studied retrospectively. The origin of the bleeding was localized preoperatively in 37 cases (88%). Four exploratory laparotomies were carried out after etiological examination including at least digestive arteriography. Hence it was always possible to localize the source of bleeding. We found it convenient to establish the order of the complementary pretherapeutic tests by taking into account two symptoms, acute active bleeding (AAB) and haemorrhage with acute anemia (HAA).

Acute Disease↗
PubMed1990

[Detection of morphine and codeine in blood samples with gas chromatography/mass spectrometry (NCI and PCI) for differentiating codeine use from use of heroin and morphine].

Morphine and codeine were isolated from blood with C18 Bond Elut columns and derivatised with pentafluoropropionic anhydride (PFPA). The PFPA-derivatives were examined by means of gas chromatography/mass spectrometry using electron impact and chemical ionisation (positive and negative mode). The negative chemical ionisation, as most sensitive, was applied for the quantitation of both examined substances in forensic blood samples.

Codeine↗
PubMed1989

["Wheeling-off" of the duodenum in gastric resection in hemorrhagic duodenal ulcer].

Truncal vagotomy associated with antrectomy is required in the treatment of terebrant and haemorrhagic ulcers of the first duodenum. The main problem lies in the closure of the duodenal stump. The "wheeling-off" procedure is a reliable technique which consist of separating the duodenum from the pancreas by carrying out dissection into the posterior wall of the duodenum, between its two muscular layers. Closure is obtained by means of a stappler. This procedure was performed in 23 patients without leakage or recurrent bleeding.

Adult↗
PubMed1989

Purification of nitrate reductase from Nicotiana plumbaginifolia by affinity chromatography using 5'AMP-sepharose and monoclonal antibodies.

Nitrate reductase was purified from leaves of Nicotiana plumbaginifolia using either 5'AMP-Sepharose chromatography or two steps of immunoaffinity chromatography involving monoclonal antibodies directed against nitrate reductase from maize and against ribulose-1,5-bisphosphate carboxylase from N. plumbaginifolia. Nitrate reductase obtained by the first method was purified 1000-fold to a specific activity of 9 units/mg protein. The second method produced an homogenous enzyme, purified 21,000-fold to a specific activity of 80 units/mg protein. SDS/PAGE of nitrate reductase always resulted in two bands of 107 and 99.5 kDa. The 107-kDa band was the nitrate reductase subunit of N. plumbaginifolia; the smaller one of 99.5 kDa is thought, as commonly reported, to result from proteolysis of the larger protein. The molecular mass of 107 kDa is close to the values calculated from the coding sequences of the two nitrate reductase genes recently cloned from tobacco (Nicotiana tabacum cv Xanthi).

Antibodies, Monoclonal↗
PubMed1989

Elevated pain threshold in patients with effort-induced angina pectoris and asymptomatic myocardial ischemia during exercise test.

The purpose of the present study was to analyze the prevalence of asymptomatic (silent) myocardial ischemia during exercise testing among patients with effort-induced angina pectoris, and further, to compare the pain threshold of patients with symptomatic and asymptomatic myocardial ischemia. A group of 26 patients comprised the study. In half of the patients myocardial ischemia during the exercise testing was silent and in one half it was symptomatic. Asymptomatic myocardial ischemia was defined as an asymptomatic ST-segment depression greater than or equal to 0.1 mV, lasting longer than 60 s during an exercise test. In patients with asymptomatic ischemia the pain thresholds both on toe and finger were significantly higher than in patients with symptomatic ischemia: mean values were 10.1 versus 4.9 mA on the toes, p less than 0.025, and 8.4 versus 2.5 mA on the fingers, p less than 0.01. We conclude that asymptomatic myocardial ischemia during exercise test is seen often in patients with angina pectoris and that this may be due to an increased pain threshold.

Aged↗
PubMed1989

[The psychosocial environment of patients with neoplasms of the head and neck. A clinical study].

A survey was made of 96 patients of the University ENT Clinic Göttingen suffering from malignomas in the head and neck region, to gain insight into the patients' personal assessment of discomfort during and after tumour therapy, and into their psychological and social environment. The questionnaires were developed in cooperation with a psychologist trained in oncology. The most important result of the survey was a tendency to idealisation and alexithymia in patients with head and neck tumours. The situation of the tumour patients is characterised by a feeling of lonesomeness and isolation within their social environment. It also became evident that some of the patients in the survey had a certain "health-promoting potential". Our results are compared with reports published on the subject so far and suggestions are made for the incorporation of psychological support during and after tumour therapy.

Adaptation, Psychological↗