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Biomedical subjects

J Wolters

Publications and source records attributed to J Wolters.

At least 37 records · Page 2Linked to original sources
PubMed1990

Brucella abortus 16S rRNA and lipid A reveal a phylogenetic relationship with members of the alpha-2 subdivision of the class Proteobacteria.

On the basis of ribosomal 16S sequence comparison, Brucella abortus has been found to be a member of the alpha-2 subdivision of the class Proteobacteria (formerly named purple photosynthetic bacteria and their nonphototrophic relatives). Within the alpha-2 subgroup, brucellae are specifically related to rickettsiae, agrobacteria, and rhizobiae, organisms that also have the faculty or the obligation of living in close association to eucaryotic cells. The composition of Brucella lipid A suggests a close phylogenetical relationship with members of the alpha-2 group. The chemical analysis of the lipid A fraction revealed that Brucella species contain both glucosamine and diaminoglucose, thus suggesting the presence of a so-called mixed lipid A type. The serological analysis with polyclonal and monoclonal antibodies is in agreement with the existence of mixed lipid A type in B. abortus. The amide-linked fatty acid present as acyl-oxyacyl residues were 3-O-C(16:0)12:0, 3-O-C(16:0)13:0, 3-O-C(16:0)14:0, and 3-O-C(18:0)14:0. The only amide-linked unsubstituted fatty acid detected was 3-OH-C16:0. The ester-linked fatty acids are 3-OH-C16:0, 3-OH-C18:0, C16:0, C17:0, and C18:0. Significant amounts of the large-chain 27-OH-C28:0 were detected together with traces of 25-OH-C26:0 and 29-OH-C30:0. Comparison of the Brucella lipid composition with that of the other Proteobacteria also suggests a close phylogenetical relationship with members of the alpha-2 subdivision. The genealogical grouping of Brucella species with pericellular and intracellular plant and animal pathogens as well as with intracellular plant symbionts suggests a possible evolution of Brucella species from plant-arthropod-associated bacteria.

Bacteria↗
PubMed1989

Thin-basement-membrane nephropathy in adults with persistent hematuria.

Thin-basement-membrane nephropathy, also called benign recurrent hematuria, is characterized by diffuse thinning of the glomerular basement membrane and by hematuria. To determine the incidence of thin-basement-membrane nephropathy among patients with idiopathic hematuria, we conducted a prospective study in the nephrology units of three large hospitals in the Netherlands. Eighty normotensive adults without azotemia underwent renal biopsy because of recurrent macroscopic hematuria (n = 26) or persistent microscopic hematuria (n = 54). Idiopathic IgA nephropathy was found in 27 of the 80 patients. Light microscopical examination showed that 42 patients had normal renal tissue. The remaining 11 patients had mesangioproliferative glomerulonephritis (n = 5), interstitial nephritis (n = 3), or focal global glomerulosclerosis (n = 3). Tissue from the 42 patients whose renal biopsy specimens were normal when examined with light microscopy was analyzed morphometrically with electron microscopy to determine the thickness of the glomerular basement membrane. Two subsets of patients were identified by this analysis. In 18, thin-basement-membrane nephropathy was found (mean basement-membrane thickness [+/- SE], 191 +/- 28 nm; normal, 350 +/- 43 nm); all but one of these 18 patients had microscopic hematuria, which persisted during follow-up (median duration, 50 months). (Of the 54 patients who presented with microscopic hematuria, 17 [31 percent] had thin-basement-membrane nephropathy.) The thickness of the glomerular basement membrane was normal in the other 24 patients (361 +/- 69 nm); during follow-up, hematuria disappeared in all 13 of these patients who had macroscopic hematuria, and hematuria resolved in 5 of the 11 patients who had microscopic hematuria. We conclude that in patients with persistent microscopic hematuria, the incidence of thin-basement-membrane nephropathy is similar to that of idiopathic IgA nephropathy. Morphometric analysis of the thickness of the glomerular basement membrane should be included in the workup of adults with persistent microscopic hematuria that is not of urologic origin.

Adult↗
PubMed1989

Phylogenetic evidence for the relationship between the genera Mobiluncus and Actinomyces.

Partial reverse transcriptase sequencing of 16S rRNA from Mobiluncus curtisii and M. mulieris clearly indicate that the genus Mobiluncus is not a member of the Bacteroidaceae but belongs to the order Actinomycetales. The highest degree of relationship is found with the genus Actinomyces which is supported by the presence of common physiological properties.

Actinomyces↗
PubMed1989

The structure and evolution of archaebacterial ribosomal RNAs.

A cladistic analysis of 553 5S rRNA sequences has revealed a Ur-5S rRNA, the ancestor of all present-day 5S rRNA molecules. Previously stated characteristic differences between the eubacterial and eukaryotic molecules, namely, the length base-pairing schemes of helices D, can be used as a marker for the various archaebacterial branches. One model comprises Thermococcus, Thermoplasma, methanobacteria, and halobacteria; a second comprises the Sulfolobales; and a third is represented only by the single organism Octopus Spring species 1. A relaxed selection pressure on helix E with subsequent deletions is observed in Methanobacteriales, Methanococcales, and eubacteria. The secondary structures are supported by enzymatic digestion and chemical modification studies of the 5S rRNAs. Reconstitution of eubacterial 50S ribosomal subunits with 5S rRNA from Halobacterium and Thermoplasma has revealed 100% incorporation, while eukaryotic 5S rRNAs yielded a 50% incorporation. Relevant positions of the small-subunit rRNA are selected to answer the question of the monophyly of archaebacteria. Eight positions account for monophyly, eight for an ancestry of eubacteria with halophile methanogens and eukaryotes with eocytes (paraphyly of archaebacteria), and two for an ancestry of eubacteria with eocytes. A refinement of the neighborliness method of S. Sattath and A. Tversky resulted in a monophyly of archaebacteria when all positions are treated equally and in a paraphyly when tranversions are weighted twice over transitions.

Archaea↗
PubMed1989

[Fibrinolytic treatment of superior vena cava syndrome, a complication of a central venous catheter].

Central venous catheterization plays a major role in anesthesia and intensive care medicine. Catheter-induced thrombosis, a common complication, develops in 15-47% of cases. A possible sequela is the occlusion of a large central vein; one early sign is edema of the upper extremities or face. Although complete occlusion of a central vein appears to be rare, this complication should be recognized in view of the extensive use of central venous catheters today. We report a case of severe superior vena cava syndrome that developed after catheterization of the right internal jugular vein. Fibrinolytic treatment using streptokinase and urokinase proved to be successful. A dose of 100,000 units/h was chosen for each agent, and heparin was added during urokinase therapy. Profound clinical improvement was observed after a few hours. Bleeding complications did not occur during the 4 days of treatment.

Catheterization, Central Venous↗
PubMed1988

Cladistic analysis of ribosomal RNAs--the phylogeny of eukaryotes with respect to the endosymbiotic theory.

A strict cladistic analysis of 5S and 16S rRNA secondary and primary structure confirms particular hypotheses concerning the phylogeny of eukaryotes: plastids of Euglena, green algae and land plants, and the cyanelle of Cyanophora share a specific character and are closely related to cyanobacteria of the Synechococcus-type. Angiosperm mitochondria share specific signatures with the alpha subdivision of rhodobacteria. Cyanophora is a member of the Euglenozoa, the Oomycetes are derived from a group of heterokont algae.

Base Sequence↗
PubMed1988

Compilation of 5S rRNA and 5S rRNA gene sequences.

The BERLIN RNA DATABANK as of December 31, 1987, contains a total of 509 sequences of 5S rRNAs or their genes, which is an increase of 45% over the last (1986) compilation (1). It covers sequences from 38 archaebacteria, 184 eubacteria, 14 plastids, 4 mitochondria, 258 eukaryotes and 11 eukaryotic pseudogenes. The BERLIN RNA DATABANK uses the format of the EMBL Nucleotide Sequence Data Library complemented by a Sequence Alignment (SA) field including secondary structure information as presented in this publication. The BERLIN RNA DATABANK is available on 360 or 1200 kb diskettes.

Animals↗
PubMed1987

Epidemiology of idiopathic glomerular disease: a prospective study.

In this study incidence rates of idiopathic glomerular disease in 1.5 X 10(6) Dutch adults between 16 and 65 years of age were determined, as well as the prevalence of these diseases in terms of indication for renal biopsy. The study was conducted between 1978 and 1985; indications for renal biopsy in decreasing hierarchical order were recently discovered uremia, nephrotic syndrome, chronic hematuria of less than two years duration with or without proteinuria or disturbed renal function, and chronic proteinuria of less than two years duration, of unknown origin. The main findings are fourfold. The incidence of IgA nephropathy and thin glomerular basal membrane lesions was high, 19 and 13 per 10(6) adults respectively, and the prevalence in patients biopsied because of non-azotemic chronic hematuria was 31% and 22%, respectively. In the normotensive non-azotemic adults biopsied because of chronic, mild proteinuria the prevalence of focal segmental glomerular sclerosis and vascular hyalinosis was both 41%. Of the patients biopsied because of nephrotic syndrome the prevalence of membranoproliferative glomerulonephritis (5%) was low, as was the incidence (less than 2 per 10(6) adults per year). Finally, the prevalence of diffuse sclerosing glomerulonephritis was 25% in patients biopsied because of uremia. This study is useful for the differential diagnosis of idiopathic glomerular disease.

Adolescent↗
PubMed1987

Evolution of organisms and organelles as studied by comparative computer and biochemical analyses of ribosomal 5S RNA structure.

The results documented in this publication demonstrate that for evolutionary studies the ribosomal 5S rRNA is a suitable object for such an investigation and that as many methods as possible should be consulted. In this study the results of biochemical and chemical experiments were combined with those of computer sequence analyses, and they revealed that these methods complement each other nicely. We are currently at a state at which we are able to well define the secondary structures of the 5S rRNAs for eubacteria, organelles, archaebacteria, and eukaryotes and we are even able to propose a secondary structure for a Ur-5S rRNA. It is also clear that in the future the present studies should be continued and extended in such a way that the tertiary structures of these molecules will become known.

Animals↗
PubMed1986

Organization of the ribosomal RNA genes in Mycoplasma hyopneumoniae: the 5S rRNA gene is separated from the 16S and 23S rRNA genes.

In order to study the organization of the ribosomal RNA genes of Mycoplasma hyopneumoniae the rRNA genes were cloned in phage vectors lambda EMBL3 and lambda EMBL4. By subcloning the restriction fragments into various plasmids and analysing the resulting clones by Southern and Northern blot hybridization, a restriction map of the rRNA genes was generated and the organization of the rRNA genes was determined. The results show that the genes for the 16S and 23S rRNAs are closely spaced and occur only once in the genome, whereas the 5S rRNA gene is separated from the other two genes by more than 4 kb.

Base Sequence↗
PubMed1985

Surgical treatment of cerebral arteriovenous malformations. Follow-up study of 43 cases.

In 43 patients with arterio-venous malformations and one patient with a cavernous haemangioma, whose angiomas were completely removed by the same Surgeon, pre- and postoperative angiograms were reviewed and the clinical results documented in a follow-up study. Mortality rate (7%) and severe disability (7%) are significantly lower than in untreated patients. A poor outcome strongly depends on the number of feeding arteries, on localization (midline) and size.

Adolescent↗