Biomedical subjects
Publications and source records attributed to W Engel.
Allelic association between cystic fibrosis and two linked markers is demonstrated in a sample of 55 German families. It is shown by example how these observations can be used for genetic risk calculation.
In the neurosurgical intensive care unit 135 patients were studied by means of multi-modality evoked potentials. The majority part of them had low scores on the Glasgow Coma Scale and a higher lever of coma according to WFNS. This fact explains the high mortality (52 per cent). These patient data were compared with the changes of evoked responses (ER) in order to learn something about the value of ER in localisation of lesions, staging, and predicting the outcome of the patients. A classification of EP alterations is introduced. There was no correlation between alteration of evoked potentials and coma stage. The analysis of latencies and inter-peak latencies revealed no correlation between comatous and alert patients. Cerebral conduction time (CCT) did not give further information. In cases of brainstem lesions the alteration of evoked responses were more marked than in the other patients. Most of the patients died who had initially marked changes in ER. The sensitivity of BAER was greater than of SSEP. A loss of response was more frequent in BAER. In deep coma stages the motor evoked responses disappeared. This fact induces problems in diagnosing brain death. Evoked potentials yield further information in patients with coma and drug therapy. They are useful in follow-ups, esp. in predicting the outcome. Evoked responses complete clinical and findings obtained via the diagnostic equipment.
An automatic programme is presented for evaluating somatosensory evoked potentials after double stimuli. The advantage of the programme is the computer-assisted procedure, the possibility of effecting changes at any time, and the imaging of both subtraction and addition curves. A variation of the programme for other modalities is possible.
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Clone pJA36B (DYS14) was isolated from a human Y chromosome enriched cosmid library. Southern blot analysis revealed a male-specific hybridization pattern. Deletion mapping with patients' DNA localized pJA36B to the median region of Yp, being present in the DNA of nine of fifteen XX-males tested so far and therefore localized in the region neighbouring the TDF-locus. Northern blot analysis showed a transcription signal in poly(A)+ RNA of human testis. Sequence analysis of the genomic DNA sequence revealed an open reading frame of 522 basepairs in the absence of control or signal sequences for the regulation of transcription or polyadenylation. This suggests that only one exon of a translatable sequence is present in clone pJA36B. A computer aided search revealed no significant homologies with known DNA or protein sequences.
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The linkage relationships between the cystic fibrosis (CF) locus and four marker loci (MET-H, MET-D, D7S8 and D7S16), allelic associations between these loci and the extent of informativity at these marker loci were investigated in a sample of 206 families with at least one child affected by CF. The data were contributed by 11 laboratories from Europe and Israel. The maximum lod scores and recombination frequency estimates (luminal diameter) (and confidence limits of luminal diameter) were: 18.3 at luminal diameter = 0.007 (0.001-0.038) for CF vs. MET, 11.0 at luminal diameter = 0.016 (0.001-0.068) for CF vs. D7S8, and 5.7 at luminal diameter = 0.0 (0.0-0.064) for CF vs. D7S16. A gene order of CF-MET-D7S8 was best supported by the data, but its preference to the order D7S8-CF-MET is mainly based on one single family. There are significant allelic associations between CF, MET, D7S8 and D7S16; these allelic associations affect the risk of random individuals to be carriers of CF.
We assessed the effect of in-hospital call on clinical performance and emotional state in seven medical interns. Clinical performance was evaluated through the use of actors who were trained to pose as patients seeking consultation because of specific medical complaints. The physician-patient interaction was scored according to predetermined criteria. There was no significant difference in interns' performance whether or not the preceding 24 hours had been spent on call. On a standardized questionnaire, interns reported significantly more fatigue and depression after call. We conclude that the major discernible effect of call is a deterioration of interns' feelings of well-being.
The nucleotide sequence of a 441-base cDNA encoding the bovine protamine has been determined. This insert, isolated from a bovine spermatid-specific cDNA library, encodes a polypeptide of 50 amino acids of which 26 are arginine, 7 are cysteine, and 2 are tyrosine. The insert contains the complete 3'-noncoding region of 150 bases and most of the 5'-noncoding region. The predicted amino-acid sequence of bovine protamine is about 96% homologous to ram protamine, 76% to boar protamine, 64% to mouse protamine 1 and 52% to human protamine 1 and contains the central, highly basic domain of four arginine clusters found in the trout protamines. Our results show that bovine protamine is 50 amino-acid residues in length and not 47 residues as previously published (Coelingh, J.P. et al. (1972) Biochim. Biophys. Acta 285, 1-14).
A 500-base cDNA encoding the bovine protamine was used for hybridization experiments with total RNA prepared from testes of prepubertal and sexually mature bulls and from pachytene spermatocytes and spermatids isolated from mature testes. The mRNA for protamine was first detected in the 7-month old testis containing 10-15% of round spermatids but was absent in testes of younger animals containing only diploid spermatogenic cells. Hybridization of the protamine cDNA with the RNA of isolated spermatids of the mature testis resulted in a prominent hybridization signal, while the faint signal obtained with the RNA of pachytene spermatocytes was found to be due to contamination of the cell preparation by spermatids. As demonstrated by in situ hybridization on testis-sections the transcripts are confined to the central cell layers of the tubuli seminiferi corresponding to the spatial arrangement of postmeiotic spermatogenic cells. The results indicate that the protamine gene in the bull is postmeiotically expressed and the mRNA is synthesized as a 680 nucleotide long molecule.
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Explore the source record for details and available documents.
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The effect of the oligopeptide antibiotic distamycin A on human lymphocyte cultures was examined. Distamycin A specifically inhibits the condensation of the Y heterochromatin and induces a fragile site in the chromosome 16 (band q22) in some individuals. The optimal culture conditions under which an undercondensation of the Y heterochromatin and an induction of the fragile site in 16q22 can be achieved by in vitro treatment of lymphocytes were determined. This also permits the use of distamycin A in routine diagnostics of human chromosomes. The use of this technique in the analysis of translocations involving the Y chromosome is presented. The distamycin A-DNA interaction and the different possible explanations for the distamycin A-induced undercondensations of the Y heterochromatin and fragile sites 16q22 are discussed.
After treatment of the ovarian and testicular membranes from several mammalian species an elevation in the specific binding of human [125I]-labelled CG could be observed. With the assumption that this effect is due to sialic acid-masked receptors, the presence of such receptors seem to be a common property of most mammalian gonads. An interesting observation was the abnormally high hormone binding capacity of the Syrian hamster ovary, as compared to other hamster species, and the lack of a neuraminidase effect in the ovary of the Syrian hamster.
Using the indirect immunofluorescent staining technique, the developmental patterns of (pro) acrosin and the outer acrosomal membrane were studied in human spermatogenesis. Specific antibodies against purified acrosin and outer acrosomal membranes from boar spermatozoa were raised in the rabbit and were found to crossreact with (pro)acrosin and outer acrosomal membrane from human spermatogenic cells. It was concluded that (pro)acrosin as well as the molecules building up the outer acrosomal membrane have been highly conserved during mammalian evolution. In the course of human spermatogenesis (pro)acrosin as well as the outer acrosomal membrane first appear in the haploid spermatids; the fluorescent areas of the individual cells steadily increase during spermiogenesis. Staining for acrosin and the outer acrosomal membrane, respectively, was found in identical compartments of the spermatogenic cells in juxtaposition to the nucleus. Round-headed spermatozoa from an infertile patient did not stain for (pro)acrosin or outer acrosomal membrane. The lack of the acrosin system was further substantiated by the gelatin substrate film technique demonstrating the absence of a gelatinolytic protease in round-headed spermatozoa. Hence, round-headed spermatozoa lack the acrosome with its constituent membrane proteins and the acrosin system housed by the acrosome of normal spermatozoa.