PubMed Health⌕ Search

Biomedical subjects

M Engels

Publications and source records attributed to M Engels.

At least 37 records · Page 2Linked to original sources

Covalent structure of two novel neutrophile leucocyte-derived proteins of porcine and human origin. Neutrophile elastase homologues with strong monocyte and fibroblast chemotactic activities.

The covalent structures of two, novel, neutrophile, leucocyte-derived, strongly basic proteins of porcine and human origin have been determined by microsequencing in combination with time-of-flight plasma desorption mass spectrometry. The porcine protein primary structure of 219 amino acid residues was shown to contain 6 cysteine residues, 2 putative carbohydrate sites and 14% basic residues. The human protein contained 221 amino acid residues of which 8 were cysteine, 4 putative carbohydrate sites and 12% basic. A 47% direct sequence similarity to human neutrophile elastase was found, but due to mutations of two of the three amino acids in the catalytic triad, proteolytic activity is absent. Modelling and alignment studies unveil a close relationship of both proteins to the serine protease family, the greatest similarity being to those serine proteases present in granules from peripheral blood cells. Both proteins have been shown to be chemotactically active for monocytes and fibroblasts in vitro.

Amino Acid Sequence↗

A model for the C5a receptor and for its interaction with the ligand [corrected].

A model of the C5a receptor was built based on the assumption that the seven membrane-spanning helices of known inward/outward direction are in an arrangement roughly similar to that in bacteriorhodopsin. Guidelines for the positioning of the helices were cysteine pairing, 'ridges into grooves' interdigitation of side chains and aromatic cluster formation. The chain segments protruding from the membrane are too short for folding into an independent ectodomain. The only longer segment (179-202) is tied down in its centre onto the membrane by a disulphide bridge and, thereby, made into two short loops as well. Ideas of the interaction of the C5a receptor with its ligand were derived mainly from the search for accommodation of the functionally essential arginine residues 40 and 74 of C5a. Asp82 is the only charged residue in a pocket approximately 20 A below the receptor surface and is conserved in the rhodopsin superfamily. It commends itself for binding Arg74 which is the tip of the flexible C-terminal chain of C5a, and rules out Arg40 in the structurally well-defined part of the molecule. The latter may bind to Glu180 at the bottom of a more shallow pocket which happens to resemble the substrate-binding site of trypsin.

Amino Acid Sequence↗

Semisynthetic des-(B27-B30)-insulins with modified B26-tyrosine.

Semisynthetic des-(B27-B30)-insulins containing modified B26-tyrosine residues were prepared to refine the understanding of the importance of position B26 with regard to biological and structural properties of the hormone. The following shortened insulin analogues were synthesized by trypsin-catalysed peptide-bond formation between the C-terminal amino acid ArgB22 of des-(B23-B30)-insulin and synthetic tetrapeptides as amino components: des-(B27-B30)-insulin, des-(B27-B30)-insulin-B26-methyl ester, -B26-carboxamide with varying C-terminal hydrophobicity of the B-chain, and [Tyr(NH2)B26]-, [Tyr(NO2)B26]-, [Tyr(I2)B26]-, [D-TyrB26]des-(B27-B30)-insulin-B26-carboxamide containing non-proteinogenic amino acids in position B26. Starting from insulin and an excess of synthetic Gly-Phe-Phe-Tyr-OMe as nucleophile, des-(B27-B30)-insulin-B26-methyl ester--the formal transpeptidation product at ArgB22--was formed in one step. Biological in vitro properties (binding to cultured human IM-9 lymphocytes, relative lipogenic potency in isolated rat adipocytes) of all semisynthetic analogues are reported, ranging from slightly decreased to two-fold receptor affinity and nearly three-fold biopotency relative to insulin. If the C-terminal tetrapeptide B27-B30 is removed, full relative insulin activity is still preserved, while the shortening results in the loss of ability to associate in solution. Only after carboxamidation or methyl esterification of TyrB26 the self-association typical of native insulin can be observed, and the CD-spectral effects in the near UV spectrum related to association and hexamerization of the native hormone are qualitatively reestablished. The results of this investigation underline the importance of position B26 to the modulation of hormonal properties and solution structure of the shortened insulins.

Amino Acid Sequence↗

[Focal nodular hyperplasia of the liver in childhood].

FNH of the liver is extremely rare during childhood. Based on relevant literature and two of our own cases the diagnosic problems are presented. Unless a clear diagnosis can be obtained by using US (Ultrasonic), CT, Szintegraphy and Angiography, laparotomy should be carried out to avoid confusion with hepatocellular carcinoma or hepatocellular adenome which can become malignant. With the exception of biopsy the higher degree of diagnostic accuracy is obtained with celiacography. Since FNH does not have a tendency towards malignancy, total extsirpation should not be attempted if vital structures are endangered.

Adolescent↗

Spatial and temporal distribution of bovine herpesvirus 1 transcripts.

Northern (RNA) blot analysis was used to determine the spatial and temporal distribution of bovine herpesvirus 1 (BHV-1) transcripts. Total RNA was isolated from Madin-Darby bovine kidney cells which had been infected with BHV-1.2b strain K22 or BHV-1.1 strain Jura in the presence or absence of metabolic inhibitors. Cloned restriction fragments representing the entire genome of strain K22 were labeled with 32P and hybridized to immobilized RNA. A total of 54 BHV-1 transcripts were found, ranging in size from 0.4 to larger than 8 kilobases (kb). The inverted repeat regions and an adjacent segment of the unique large part of the BHV-1 genome encoded three major immediate-early (IE) transcripts and one minor IE transcript enriched after cycloheximide treatment of infected cells. Late transcripts were identified by drastically reduced abundance after cytosine arabinoside (araC) treatment. Twelve late transcripts were encoded mainly by the unique long genome region, with a cluster of four transcripts located on HindIII fragment K (map units 0.677 to 0.733). The 21 transcripts unaffected by araC treatment were defined as early; they showed dispersed locations over the whole genome, with a cluster on the unique short sequence. The 17 remaining transcripts could not be classified unambiguously as early or late by these techniques. The IE transcript with a size of 4.2 kb exhibited homology with the single IE gene of pseudorabies virus, and the IE transcript with a size of 2.9 kb was encoded in part by the genome region known to be transcriptionally active during latency.

Animals↗

[Report of experiences with AIDS education in schools by the public health service].

AIDS information work is very work-intensive if it is to be pursued with consequence and effect. This is a report on the work done in the course of one year at 47 schools and on the experience collected: --Many evening events have to be visited (parents' evenings and get-togethers, meetings of the parent councils). Such events are absolutely imperative if work at the schools should be meaningful and effective. --Working in Small groups (class groups) is much more time-intensive but also clearly more effective and should therefore always be preferred to large-scale events. --Working at different types of schools with different age levels makes great demands on the flexibility and intuitive abilities of the AIDS expert.

Acquired Immunodeficiency Syndrome↗

[Edentulous patients visiting a dental ombudsman. Their questions and problems].

Data are presented of 321 edentulous patients (women 67%), mean age 65 years, who visited a dental ombudsman in the period September 1980-May 1987. Many of these patients had several complaints: 41.5% three and more. Many of the problems (134 patients) are behavioural and psychological by nature. The majority of the patients (65%) ask for advice during the consultation. One may get the impression that this group of patients has had these problems already for a longer period and that they feel that a general practitioner can't help them effectively. For this special group of patients a dental ombudsman may serve as a useful mediator.

Adult↗

[Anorectal prolapse].

14 children with anorectal prolapse have been treated by injection therapy with 25% saline solution. Experimental studies have shown no noticeable reactions between rectum and surrounding area, as far as adhesion and thus rectal fixation are concerned. Manometric examinations show an increased contraction tendency of the Musculus puborectalis after injection, which should lead to a depression of the kink at the rectosigmoidal junction and to a healing of the prolapse. The associated stool-regulating measures contribute a lot to remedy the prolapsed rectum.

Animals↗

[Diagnosis of functional anorectal disorders in childhood].

Constipation of all degrees is a frequent complaint in childhood. Differentiation between constipation with or without normal ganglia necessitates the following investigations: clinical examination, manometry, rectoscopy, rectal mucosal biopsy, rectal full thickness biopsy. The technique of these investigations as well as their risks are discussed.

Anal Canal↗

Bovine herpesvirus 1: molecular and antigenic characteristics of variant viruses isolated from calves with neurological disease.

This report presents data showing that several virus isolates recovered in Argentina, mainly from calves with non-purulent meningo-encephalitis, represent a hitherto unrecognized antigenic variant of BHV-1. The following experimental approaches have been adopted to demonstrate both the unique features among and the relatedness with BHV-1 of these isolates: i) crossed serum neutralization test with rabbit immune sera, ii) analysis by SDS-polyacrylamide gel electrophoresis of radio-labeled virus induced polypeptides and glycoproteins, iii) discriminating reactivity of a panel of monoclonal antibodies which recognize known virus types, and iv) restriction endonuclease analysis of viral DNA. Another strain of BHV-1, which exhibits a specific neuropathogenic potential [Hall et al., Austral. Vet. J. 42, 229-237 (1966)] shares all major features with the viral strains originating from Argentina. Our results imply that antigenic variants of BHV-1 exist and that they can be accurately and easily identified and differentiated by the available methods.

Animals↗

The genome of bovine herpesvirus 1 (BHV-1) strains exhibiting a neuropathogenic potential compared to known BHV-1 strains by restriction site mapping and cross-hybridization.

Bovine herpesvirus 1 (BHV-1) strains can be differentiated by their DNA and polypeptide patterns, and by antigenic properties as demonstrated by monoclonal antibodies. We classified the BHV-1 strains according to these data as BHV-1.1, BHV-1.2 (a/b) and BHV-1.3 (a/b). BHV-1.1 and BHV-1.2 correspond to the well known 'common' BHV-1 strains, whereas BHV-1.3 has only recently been recognized and exhibits a neuropathogenic potential. In the present paper we describe the structural genome characteristics of BHV-1.3 compared to those of the other BHV-1 strains, examined by means of restriction site mapping, electron microscopy and cross-hybridization. Our results also confirm and complete data concerning BHV-1.1 and BHV-1.2 published by other authors. The following main conclusions can be drawn from our investigations: BHV-1.1 and BHV-1.2 differences are restricted to distinct genomic regions, characterized by loss or gain of restriction sites. BHV-1.3, however, differs from the other BHV-1 strains in restriction site alterations throughout the whole genome. Electron microscopy showed the typical BHV-1 DNA structure for BHV-1.3. Genetic homology between BHV-1.1 and BHV-1.2, reported to be about 95%, was confirmed by cross-hybridization, and a similar high base sequence homology for BHV-1.3 could be shown.

Animals↗

Genomic and antigenic comparison of an equine herpesvirus 1 (EHV 1) isolate from the 1983 Lippizan abortion storm with EHV 1 reference strains.

An EHV 1 isolate from the Lippizan Stud at Piber, which caused the abortion and paresis outbreak in 1983, was investigated using 3 known subtype 1 and 2 subtype 2 strains for comparison. Broad-scale restriction enzyme analysis as well as cross-neutralization with hyperimmune sera produced in rabbits were performed, and SDS-PAGE of infected cell proteins was conducted on a limited scale. The Piber isolate was clearly classified as a subtype 1 strain of EHV 1, and showed closest resemblance in its restriction patterns with a British EHV 1 strain, which originated from an outbreak with paretic symptoms. A second Piber isolate from the same outbreak examined to limited extent only was practically indistinguishable from the first one, as could have been expected. A thoroughly controlled systematic vaccination program with existing commercial vaccines against EHV 1 should protect the endangered Lippizan horses population against the abortigenic and less certainly against the paretic syndromes caused by this virus. According to data presented, a protection against respiratory disease is less probable.

Animals↗

European isolates of bovine herpesvirus 1: a comparison of restriction endonuclease sites, polypeptides, and reactivity with monoclonal antibodies.

Eleven European isolates of bovine herpesvirus 1 (BHV-1), together with two reference virus strains were compared by restriction endonuclease digestion, by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and by their reactivity with a panel of monoclonal antibodies (McAb's). Based on the cleavage pattern of viral DNA with the restriction endonuclease Hind III the strains could be assigned to one of two established major virus types. Analysis by SDS-PAGE of viral polypeptides revealed that four protein species either displayed virus type or subtype specific minor variation of migration characteristics. Of 43 McAb's tested all reacted with all type 1 strains, whereas five antibodies failed to recognize some of the type 2 viruses. The existence of type specific variations among virus specified proteins was further evidenced by the recovery of one McAb recognizing type 1 viruses only. The data show that BHV-1 isolates can be assigned to established virus types according to the SDS-PAGE profile of viral proteins or the selective reactivity with type specific McAb's.

Animals↗

[Nail bed changes in the neonatal period].

In the years from 1973-1983, 36 children, ranging in ages from 14 days to 4 years, with ingrown toenails, which they had had since birth, were admitted for stationary treatment. For 26 of the children, the nails of both large toes were ingrown. In eight cases the smear from the nail wall revealed pathological germs of differing types. Conservative therapy was attempted in each case without success. The operative treatment consisted of completely removing the nail in 50%, an incomplete removal in 30%, and in all cases resection of the nail wall. None of the children showed a relapse. The treatment was completed within 14 days following the operation and conservative treatment. The cause is assumed to be a congenital hyperplasia of the nail bed.

Bacterial Infections↗