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Biomedical subjects

W Friedl

Publications and source records attributed to W Friedl.

At least 127 records · Page 7Linked to original sources
PubMed1991

Familial defective apolipoprotein B-100: molecular basis, prevalence and clinical features.

Familial defective apo B-100 is an autosomal dominant trait which causes moderate to severe elevation of LDL-cholesterol in the plasma and may predispose the coronary heart disease. The primary defect is a single amino acid change (Arg3500 to Gln), which disrupts the normal binding of LDL to the LDL-receptor. The mutation occurs at an estimated frequency of 1/600 in the normal population and is, therefore one of the most common known single-gene defects causing an inherited abnormality.

Alleles↗
PubMed1991

[A simple, rapid and economical method of distal interlocking nailing in upper and lower leg intramedullary nailing].

Distal interlocking of intramedullary nails is associated with a relatively high radiation exposure. For the reduction of fluoroscopy time and surgeon's hands irradiation, many devices have been developed so far. In this paper, a simple free-hand-technique is presented. The mean fluoroscopy time in 30 femur and 10 tibia interlocking intramedullary nailing procedures was one minute. The technique avoid the central beam of the fluoroscope and does not require specific instruments. The technique is based on the axial placement of a 2 mm K-wire in the interlocking screw holes. A centrally perforated 4.5 mm drill is placed over the K-wire. Therefore in this technique a perfect centrally placement of the K-wire is not necessary. The drill is guided by the K-wire thereby avoiding complications such as drill failure or deviation of the drill direction.

Bone Wires↗
PubMed1991

[Genetic predisposition to hypercholesterolemia and coronary heart disease. DNA polymorphism in the apolipoprotein B gene as a possible cause].

It has been demonstrated in numerous studies that hypercholesterolemia is an important independent risk factor for the development of coronary heart disease. Besides exogenous factors like diet and physical exercise genetic predisposition is a major determinant of serum cholesterol levels. Apolipoprotein B-100 (apo B-100) is the protein constituent of LDL which serves as ligand to the LDL-receptor. A hypervariable region containing repetitive elements adjacent to the apo B gene was used as marker to study the role of genetic variation in this gene in the development of elevated serum lipid levels and premature coronary heart disease. A group unrelated patients with severe coronary heart disease and normal controls were studied. Using a high resolution method we could identify 14 different alleles. Alleles with a large number of repetitive elements were associated with coronary heart disease. The same alleles were weakly associated with elevated levels of serum levels of cholesterol, triglycerides and apolipoprotein B.

Alleles↗
PubMed1991

A polymorphism in a region with enhancer activity in the second intron of the human apolipoprotein B gene.

A 443-base pair fragment (+622 to +1064) from the second intron of the human apolipoprotein B gene was shown to contain a tissue-specific enhancer when placed in front of an apolipoprotein B promoter-chloramphenicol acetyltransferase construct in transfection experiments. To identify potential regulatory mutations in this region of the gene, DNA from various subjects was examined for the presence of point mutations by means of chemical cleavage of mismatched heteroduplexes. An A----G substitution within the second intron of the gene at position +722 was identified in three unrelated subjects and confirmed by DNA sequencing. Although the base substitution was contained within a nuclear protein-binding site, as determined by DNase I footprinting, it did not appear to affect the protein/DNA interaction in its vicinity, as shown by gel retardation experiments. The single base substitution at position +722 abolishes a StyI restriction site, thus creating a StyI polymorphism. Using allele-specific oligonucleotides, we screened the DNA of 172 subjects for the presence of this polymorphism: two other subjects carrying the polymorphism were found. In each of the five unrelated subjects, the polymorphism was associated with the same haplotype.

Apolipoproteins B↗
PubMed1990

[Does sonographic evidence of blood in the abdomen following blunt abdominal trauma present an indication for surgery in every case?].

In a comparative study based on the diagnosis of blunt abdominal trauma, the accuracy of ultrasound (US) proved inferior, with 82-91%, to that of diagnostic peritoneal lavage, with 97-100%. The sensitivity of US, i.e. the proportion of patients with blood in the abdomen who had an abnormal test result (positive sonography) was 94%. The reasons for this may be either patient-related (severe obesity, intestinal gas superposition) or examiner-related (differing previous experience). The specificity for correct elimination of abdominal lesions was 100%. When no intra-abdominal liquid was present none appeared in the US picture; however, 3-13% of cases where intra-abdominal liquid was present this was not revealed by US. If only a small amount of intra-abdominal liquid is demonstrated after blunt trauma, the adoption of a wait-and-see attitude is justified. In intensive care conditions US can be repeated several times if necessary. In this study US showed deterioration in these circumstances in 25%, and in 21% it must be expected that an operation will be necessary.

Abdominal Injuries↗
PubMed1990

Familial defective apolipoprotein B-100: a mutation of apolipoprotein B that causes hypercholesterolemia.

Familial defective apolipoprotein B-100 is a genetic disorder of apolipoprotein B-100 that causes moderate to severe hypercholesterolemia. A single amino acid mutation in apolipoprotein B diminishes the ability of low density lipoproteins to bind to the low density lipoprotein receptor. Low density lipoproteins accumulate in the plasma because their efficient receptor-mediated catabolism is disrupted. This mutation has been identified in the United States, Canada, and Europe and is estimated to occur at a frequency of approximately 1/500 in these populations. Thus, it appears that this newly described disorder may be a significant genetic cause of hypercholesterolemia in Western societies.

Apolipoprotein B-100↗
PubMed1990

Hypervariability in a minisatellite 3' of the apolipoprotein B gene in patients with coronary heart disease compared with normal controls.

Several recent reports have examined whether there is a correlation between the presence of some minor alleles of the highly polymorphic apolipoprotein B gene and atherosclerosis and premature heart disease. The present study extends this investigation. A high-resolution method was used to study the allele frequencies of a hypervariable minisatellite region close to the apolipoprotein B gene in 110 patients with severe coronary disease and in 117 normal controls. Alleles containing 38, 44, 46, or 48 hypervariable elements showed an association with coronary heart disease. These alleles were also associated with elevated serum levels of total cholesterol and apolipoprotein B among patients and with elevated serum levels of total triglycerides among controls. The hypervariable region showed strong linkage disequilibrium with a polymorphic EcoRI site in exon 29 and was in linkage equilibrium with a polymorphic MspI site in exon 26. Two patients carried a base change at codon 3500 that results in an arginine-to-glutamine substitution; the base change was linked in both instances to the allele with 48 hypervariable elements.

Adult↗
PubMed1990

Indication, management and results of surgical therapy for pathological fractures in patients with bone metastases.

The most important localized bone lesions to cause pathological fractures are metastases of various primary tumors. Among these, breast cancer represents about 2:3. The survival time of patients with pathological fractures is only 4 to 15 months, and therefore an immediate restoration of loading capacity and full function should be attempted. This, and immediate pain relief, can be achieved by operative stabilization of the fracture. To avoid postoperative local radiotherapy, the metastases should be resected completely with tumor-free margins. Biomechanical aspects of the different parts of the skeleton must also be considered to avoid mechanical failure of the osteosynthesis. Four different parts of the skeleton with different biomechanical characteristics (lower and upper extremity, spinal column and pelvis) must be considered. Only in patients with very advanced cancer and poor general condition, may intramedullary nailing be performed without resection of the metastasis, to obtain pain relief and partial restoration of the function of the extremity. When managing pathological fractures caused by metastases, good functional results can be obtained, with these principles in mind, when the general condition of the patient is moderately good at the time of operation. Joint and muscular preserving devices allow faster and easier rehabilitation, and postoperative morbidity is reduced. The devices used in the different parts of the skeleton are presented.

Arm↗
PubMed1990

[The significance of individual patient characteristics for loading capacity and deformation of the proximal end of the femur].

The influence of such individual characteristics as age, sex, morphological characteristics (CDD angle, length of femoral neck, total and medullary diameter and score on the Singh osteoporosis index) on the loading capacity and deformation of the proximal end of the femur were determined in this experimental study. In all, 341 femora taken from the cadavers of persons who had died at over 60 years of age were tested under alternating load in up to 4000 cycles and, if no instability occurred, also under static load. The loading capacity and deformation were compared. The loading capacity was significantly higher in male femora with (5441 +/- 257 N) than in female femora (4273 +/- 1850 N). The loading capacity also decreased with increasing age and with decreasing CCD angle and Singh index score (higher degree of osteoporosis). Because of the high standard deviation in each group these differences were not significant.

Age Factors↗
PubMed1989

Pseudodeficiency of arylsulfatase A: a common genetic polymorphism with possible disease implications.

At the locus for arylsulfatase A (ASA) at least four to five alleles exist: besides the normal ASA+ and at least two to three deficiency alleles (ASA-), a pseudodeficiency allele, ASAp, is known. On SDS-PAGE the ASAp enzyme migrates slightly faster than ASA+. Treatment of extracts from cells with ASA+/ASA+, ASAp/ASAp, or ASA+/ASAp genotypes with endoglycosidase F leads to the same deglycosylated subunit pattern. Presumably the degree of glycosylation is lower in ASAp than in ASA+. In a large-scale screening project we determined a gene frequency of 7.3% for ASAp. Thus, the ASA locus is polymorphic. In seven families, ASAp showed a codominant mode of inheritance with ASA+. Homozygosity for ASAp has no obvious clinical consequences. In subjects with the compound genotype ASA-/ASAp, the residual enzyme activity may fall below a critical threshold, so that the substrate can no longer be hydrolyzed sufficiently. Since these compounds are not so rare (estimated frequency 0.073%), this mechanism could be of importance in neuropsychiatric disorders with late onset.

Alleles↗
PubMed1989

[Indications, technique, results and value of modified radical mastectomy].

Modified radical mastectomy is the most frequent operation performed for therapy of primary breast cancer. In T1 breast cancer patients the breast-conserving therapy is used in up to 40-60% of the patients. In T2 breast cancer patients modified radical mastectomy is still the most frequently used regimen (72-79%). Tumor, breast and psychological characteristics as well a technical facilities must be considered, when determining if modified radical mastectomy is indicated. The operation technique is presented.

Breast↗
PubMed1989

[The value of ultrasound in the diagnosis of capsule ligament injuries of the upper ankle joint].

Ankle ligament injuries are usually diagnosed by clinical and radiological examination. In this study we tried to determine the accuracy of dynamic sonography in the diagnosis of ankle ligament injuries. From 1 April 1987 to 1 July 1988, 72 patients with ligamentous injuries of the ankle were examined sonographically. The dynamic stability of the anterior talofibular ligament was determined by measuring the length of the ligaments under normal and stressed conditions. The anatomical course of the ligaments was used as the plane of section. Clinical and radiological examinations were used to determine whether an operation was indicated, and the results of these examinations were compared after the operation with the sonographic and intraoperative findings. Dynamic examination of the stability of the anterior talofibular ligament yielded findings compatible with the intraoperative findings in 64 of the 72 cases (88.8%). The mean difference in length between normal and stressed conditions was 7.4 mm, with a range of 6-12 mm in the case of rupture of the ligament. A high level of agreement between sonographic and intraoperative findings was also found for the calcaneofibular ligament. In 62 of the 72 cases (86.1%) a correct diagnosis was possible. The mean difference in length in this plane of section was 10.6 mm, with a range of 7-17 mm. The sensitivity and specificity of ultrasound in the diagnosis of rupture of the ligaments were between 80% and 90%, respectively, and the positive predictive value was about 95%. Sonography with a high-resolution scanner allows a correct diagnosis of ligamentous lesions at the ankle joint in 80-90% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

High-resolution analysis of a hypervariable region in the human apolipoprotein B gene.

A hypervariable region occurs immediately 3' of the human apolipoprotein B gene. Several allelic variants of this tandemly repeated sequence can be resolved by genomic blotting. Higher resolution among size variants may be obtained by polymerase-chain-reaction amplification of this region followed by electrophoresis in a denaturing acrylamide gel. Fourteen different alleles containing 25-52 repeats of the basic 15-bp unit were distinguished in a population study of 318 unrelated individuals. This approach should be applicable to pedigree and linkage analysis with the apolipoprotein B gene or other tandemly repeated sequence elements.

Alleles↗
PubMed1988

Persistence of species variation and regional heterogeneity of the apparent molecular masses of benzodiazepine-binding proteins after deglycosylation.

Brain membrane preparations of different vertebrates were photoaffinity labeled with [3H]flunitrazepam and subsequently deglycosylated with endoglycosidase F and peptide N-glycopeptidase. SDS-polyacrylamide gel electrophoresis followed by fluorography revealed that each benzodiazepine-binding protein is deglycosylated in two steps, indicating that each protein has two glycosylation sites. Species variation of the apparent molecular masses of the benzodiazepine-binding proteins and regional heterogeneity in avians persist after deglycosylation. These results indicate that the alpha-subunit(s) of the GABA/benzodiazepine receptor has undergone electrophoretically detectable changes in its amino acid composition during vertebrate evolution. The existence of at least two different alpha-subunits in avians is further substantiated.

Animals↗