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Biomedical subjects

W Lenz

Publications and source records attributed to W Lenz.

At least 55 records · Page 3Linked to original sources

Lytic activities, protein profiles and morphologic characteristics of new bacteriophages isolated from canine and human Staphylococcus aureus strains.

The lytic activity, protein profile and morphology of five newly isolated phages from canine Staphylococcus aureus strains and one from a human S. aureus strain were compared with those of selected phages in the international phage sets (IPS). Five canine phages lysed 57 (76.0%) of 75 canine isolates of Staphylococcus aureus from Nigeria at routine test dilution (RTD) while 34 (IPS) phages typed only 31 (41.3%) strains at RTD or/and 100-RTD. The new human phage lysed 11 (14.7%) of 75 strains isolated from human diarrhoea. The new phages were readily propagated, specific in activity and stable during storage at 4 degrees C. Prominent proteins detected by SDS-PAGE indicated similarities between some of the phages but one canine phage was distinctly different, as was its morphology which was an isometric head with a short tail compared to oval heads and long tails which characterized others. IPS phages in the same serologic group had similar protein profiles but no correlation was observed with lytic groups. The use of protein profile and electron micrographs allowed classification of the phages into serogroups. It is concluded that the newly isolated canine phages could be very useful in typing Nigerian canine strains of S. aureus.

Animals↗

Detection of enterotoxigenicity of Staphylococcus aureus strains: a comparative use of the modified Ouchterlony precipitation test, reversed passive latex agglutination test, and avidin-biotin ELISA.

The avidin-biotin enzyme-linked immunosorbent assay (ELISA), reversed passive latex agglutination (RPLA) test, and the modified Ouchterlony precipitation test (MOPT) were compared in detecting enterotoxin production by Staphylococcus aureus strains. A total of 1015 strains isolated from human beings, animals, and foods were tested for staphylococcal enterotoxins A (SEA), B (SEB), and C (SEC). Of these, 495 (48.8%), 467 (46.0%), and 204 (20.1%) were classified as enterotoxigenic by the ELISA, RPLA test, and MOPT, respectively. The difference in the number of strains classified as enterotoxigenic by the ELISA and RPLA test was not significant (P > or = 0.05; chi 2), but both tests detected significantly (P < 0.001; chi 2) more enterotoxigenic strains than the MOPT. The combined use of the three assay systems classified 258 (25.4%), 278 (27.4%), and 263 (25.9%) of 1015 strains tested as positive for SEA, SEB, and SEC, respectively. However, the three systems were all positive in only 29.1% of SEA-producing strains, 32.0% of SEB-producing strains, and 25.1% of SEC-producing strains. The MOPT was negative when the corresponding ELISA and RPLA test were positive (46.9% for SEA, 43.5% for SEB, and 40% for SEC); the RPLA test was negative when the corresponding ELISA was positive (10.5% for SEA, 15.5% for SEB, and 25.5% for SEC); and the ELISA was negative when the RPLA test was positive (13.6% for SEA, 9.0% for SEB, and 9.5% for SEC). All factors considered, the RPLA test appears most suitable for quantitatively screening large numbers of strains for staphylococcal enterotoxins.

Animals↗

Etiological study on isolated proximal intercalary type of congenital limb deficiency in Hungary, 1975-1984.

A population-based and validated data set of 14 cases with isolated proximal intercalary type of congenital limb deficiency born in Hungary between 1975-84 was evaluated. Two cases had phocomelia of upper limbs, while 12 cases were affected with classical intercalary defects mainly in femurs. Of 14 cases, 13 had unimelic manifestation and both sexes were equally affected. The intrauterine growth retardation, the excess of second birth order, a higher rate of acute maternal disorder of the respiratory system and the lack of familial cluster are noteworthy. The vascular disruption hypothesis seems to be the most plausible explanation for the origin of isolated proximal intercalary defects.

Birth Order↗

Production of toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria.

The production frequency of toxic shock syndrome toxin-1 (TSST-1) amongst Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria was investigated. Of 1015 strains tested, 120 (11.8%) were positive for TSST-1. Thirty one (16.0%) of 194 strains from human diarrhoea and wounds were positive compared to 47 (7.1%) of 666 isolates from eight animal species. Goat strains were most often positive for this toxin (17.0%). A total of 42 (27.1%) of 155 strains from foods were positive for TSST-1. Regardless of source, phage non-typable strains (48.3%) were most common amongst TSST-1 producers followed by strains sensitive to phages in several groups (mixed), 18.3%, and phage group III strains (17.5%). Only 6 were phage group I strains (5.0%). TSST-1 producing strains were mostly resistant to penicillin. Eighty-four (70.0%) TSST-1 producers were also enterotoxigenic with staphylococcal enterotoxin C (SEC) most frequently elaborated as 46 (38.9%) strains were positive. However, 42 (35.5%) and 39 (32.5%) strains producing TSST-1 were also positive for SEA and SEB, respectively. It was concluded that TSST-1 producing strains of S. aureus are widespread in humans, animals and foods in Nigeria and such distribution may play some role in the epidemiology of toxic shock syndrome, the prevalence of which is currently unknown in the environment.

Animals↗

[Ocular symptoms in a family with pseudo-Ullrich-Turner syndrome].

We report on a family with some features of the Pseudo-Ullrich-Turner-Syndrome, so-called Noonan-Syndrome. Besides low-set ears, microgenia, short neck, pterygium colli, low-anterior hair line and small stature as well as partial scoliosis, partial cubitus valgus and camptodactylia, retinal detachment, disturbances of the eye motility, keratoconus, unilateral ptosis and antimongoloid slant of the palpebral fissures in different expression are described. The caryotype was normal. Some of the features can be seen within at least 2 generations of the family. It seems to be an autosomal genetic mode of transmission. Differences and common characteristics in comparison to the literature are shown. Differential diagnostic aspects are described. A definite relation to a syndrome already described is not possible.

Adolescent↗

Exfoliative toxin production by Staphylococcus aureus strains isolated from animals and human beings in Nigeria.

Strains of Staphylococcus aureus isolated from lesions and apparently healthy animals, human diarrhoea and wounds in Nigeria were phage typed and tested for exfoliative toxin (ET) production using the modified Ouchterlony double diffusion test. Thirty-four (4.0%) of 860 strains tested produced exfoliative toxins A (ETA), B (ETB) or a combination. ETA was produced singly by 91.1% of the toxigenic strains. Twenty-six (3.9%) of 666 animal strains were toxigenic compared to 8 (4.4%) of 194 strains from human beings. Overall, a majority of ET-producing strains were non-typable (58.8%), followed by phage group II strains (17.7%). The detection of a similar frequency of production of ET by strains of S. aureus from animals and non-scalded skin syndrome cases indicates that animals may serve as a reservoir for human infection.

Animals↗

Birth prevalence of different congenital limb deficiency types in a revised, population based Hungarian material, 1975-1984.

998 cases affected with limb reduction deficiency were evaluated in Hungary, 1975-1984. Through the check-up of other sources of ascertainments, the Hungarian Congenital Abnormality Registry was found to be 98.4% complete. The proportion of misdiagnoses was 12.6%. In the period encompassed by the study, the birth prevalence of revised cases affected with congenital limb reduction deficiency was 0.55 per 1000 total births. Isolated and multiple cases were separated. The birth prevalence of revised isolated cases was 0.35 per 1000. Six types were separated based on their phenotypic manifestations. As the number of affected limbs, ratio of isolated and multiple cases and sex ratio showed obvious differences, etiological factors should be evaluated separately in these different types of congenital limb deficiencies.

Congenital Abnormalities↗

New aspects of lumbar disc disease. MR imaging and histological findings.

Magnetic resonance imaging (MRI) and plain X-ray and CT studies were performed in patients with a history of lumbar back pain due to spinal disc disease. Spin-echo pulse sequences (SE), phase-contrast techniques (partial saturation sequences with delayed readout, PS), and fat-suppressing inversion recovery sequences (STIR) were employed. In 74 of 325 patients, PS and STIR images displayed vertebral marrow changes adjacent to the end-plates of the affected segments. Bacterial infection, however, could be excluded. In six patients histological diagnosis showed substitution of hematopoietic marrow by fatty tissue, cartilaginous particles, degeneration of fat cells, and an increase in extracellular fluid with different components. The etiology is still unclear, but a correlation with lumbar disc disease is demonstrated. These vertebral marrow changes were best displayed with STIR and phase-contrast MR sequences, both providing contrast changes superior to T2-weighted SE techniques.

Adolescent↗

Use of a ribosomal RNA gene probe for the epidemiological study of methicillin and ciprofloxacin resistant Staphylococcus aureus.

Conventional bacteriophage typing was combined with ribotyping in the analysis of methicillin and ciprofloxacin resistant Staphylococcus aureus strains isolated in increasing frequency since the introduction of the new 4-quinolones as therapeutic agents in the Tel-Aviv Medical Center. Whole-cell DNA was digested with EcoRI and HindIII restriction endonucleases. Agarose gel electrophoresis, Southern blotting, and hybridization by biotinylated probe DNA coding for ribosomal RNA revealed 7 to 14 bands. Analysis of the patterns established a single DNA type in EcoRI as well as in HindIII digests for all strains except one. Control strains from other sources differed in their band patterns. Bacteriophage typing confirmed the results of DNA typing. Thus, the frequent occurrence of staphylococcal isolates resistant to 4-quinolones in the hospital was not due to mutational development of resistance in many strains, but to the spread of a resistant strain.

Anti-Infective Agents↗

Fraser syndrome (cryptophthalmos with syndactyly) in the fetus and newborn.

Clinical and autopsy findings in two fetuses and one newborn infant with Fraser syndrome are presented. Discussion focuses on the range of phenotypic expression within this autosomal-recessive disorder, the resulting difficulties in prenatal and postnatal diagnosis, and on the concept of a neurocristopathy as underlying disturbance.

Abnormalities, Multiple↗

Staphylococcus aureus phage types in barrier-maintained colonies of SPF mice and rats.

From 1985 to 1987 within the framework of our health monitoring programme, the occurrence of S. aureus in our rodent colonies and their caretakers have been surveyed. To obtain further information on S. aureus subtypes, isolates were subjected to phage typing using the international set of bacteriophages. Strains derived from pathological processes but also randomly chosen isolates from healthy animal carriers and the personnel underwent lysotyping. With respect to the animals every hygienic unit harbours its characteristic S. aureus lysotype(s). Among these, usually one pattern dominates in pathological processes and healthy carriers, although the spectrum of phage types distributed among the caretakers shows a much greater variation and some of the attendants are suspected to be not only transient carriers. A comparison with an earlier investigation done in our institute about a decade ago (Lenz et al. 1978) shows the prevalence of completely different phage types.

Animals↗

Robinow syndrome with parental consanguinity.

We describe the clinical features of Robinow syndrome in the first child of a consanguineous Turkish couple. This observation supports the view that severe vertebral anomalies are a feature of the autosomal-recessive form of Robinow syndrome.

Abnormalities, Multiple↗

Nasal carriage of Staphylococcus aureus treated with topical mupirocin (pseudomonic acid) in a children's hospital.

2% mupirocin ointment applied intra-nasally for 5 days was assessed for elimination of nasal carriage of Staphylococcus aureus in 31 staff members in a children's hospital. Three volunteers failed to complete the trial because of side effects, i.e. buccal reddening and swelling, and unpleasant taste. During treatment staphylococcal nasal carriage was not found in any case; of the 24 post-treatment nasal swabs taken 4 days after treatment 22 were still negative. Re-colonization with S. aureus of different phage types occurred in the remaining two cases.

Administration, Intranasal↗

Can the association of athymic mice (Han:NMRI-nu) with Staphylococcus sciuri prevent infection with Staphylococcus aureus? Experiences from a field study.

An attempt was made to prevent the introduction of Staphylococcus aureus into a newly established colony of Han:NMRI-nu mice by means of preassociation with the rodent-specific Staphylococcus sciuri. Despite the successful colonization of the mice with S. sciuri the establishment of S. aureus into the colony was not impeded, and abscesses were observed with an increasing frequency until the end of the study. Random samples revealed the phage pattern 3A/3C/55/71 or very similar ones. A caretaker was identified as a possible vector of transmission, since he was found to be colonized with this S. aureus phage type previous to the outbreak. Finally, the later occurrence of Citrobacter freundii and Pseudomonas aeruginosa serovar P10 in the colony led to the decision to give it up after 21 months of existence.

Animals↗

[Bone diseases: review and classification of congenital developmental disorders].

There is no complete and satisfactory system of classification for constitutional bone diseases available at present. A combination of precise phenotypical description and genetical analysis has been shown, however, to increase our understanding of the basic defects and to allow an etiological classification of an increasing number of bone diseases. Examples are given to illustrate the usefulness of Mendelian analysis (autosomal dominant and recessive inheritance, X-linkage), microcytogenetics, cellular pathology, enzyme biochemistry, analysis of the gene products, and DNA analysis. The phenotype cannot be understood without knowledge of its genetic basis, but knowledge of the genetic basis laid down in the DNA is only useful in connection with knowledge of the phenotype, which cannot be derived from knowledge of the DNA.

Bone Diseases, Developmental↗

The Lenz microphthalmia syndrome.

We examined two patients with the Lenz microphthalmia syndrome. When findings from these two patients and those from ten other patients in the literature were combined, the following abnormalities were observed: microphthalmos in all patients; developmental retardation in 11 patients (92%); external ear abnormalities in ten patients (83%); microcephaly in ten patients (83%); blepharoptosis in nine patients (75%); skeletal anomalies (excluding digital anomalies) in eight patients (67%); dental abnormalities of number and position in eight patients (67%); digital anomalies in seven patients (58%); urogenital anomalies in six patients (50%); and cleft lip and palate abnormalities in four patients (33%). Cardiac anomalies, imperforate anus, hearing loss, spastic diplegia, sacral pits, webbed neck, and abnormal dermatoglyphs were rarely seen. One of our two patients had a dislocated lens and retinal detachment.

Abnormalities, Multiple↗