[Hypercalcemic crisis and multiple osteolyses in an elderly patient].
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Aged↗
Biomedical subjects
B Jansen
Publications and source records attributed to B Jansen.
Characterization of the inner surface of tubular substrates by contact angle measurement.
A new method for the direct measurement of the contact angle on the inner surface of tubular substrates is described. It is shown that the measured contact angles are in good accordance with those obtained on flat surfaces.
Chemical Phenomena↗
New aspects in the pathogenesis and prevention of polymer-associated foreign-body infections caused by coagulase-negative staphylococci.
The significance of polymer-associated infections caused by coagulase-negative staphylococci is discussed. The aspects of bacterial adhesion to polymeric materials as the first important pathogenetic step in the development of such infections are treated. The role of extracellular slime substance (ESS) produced by the bacteria in the pathogenesis is elucidated and newer results concerning the interference of ESS with host defense mechanisms and antibiotic therapy are presented. As an approach to the prevention of polymer-associated foreign-body infections, the modification of the polymeric materials is introduced. Results of recent studies to achieve antiadhesive materials by radiation modification of polymers as well as the development of antimicrobial surfaces by incorporating or bonding antibiotics to polymers are presented.
Bacterial Adhesion↗
An immunohistochemical and electron microscopic study of extra-renal basement membranes in dogs with Samoyed hereditary glomerulopathy.
Samoyed hereditary glomerulopathy (SHG) in dogs has been employed as a model for human hereditary nephritis (HN), since affected dogs and patients show splitting of glomerular capillary basement membranes by electron microscopy (EM) and absent staining of glomerular capillaries for Goodpasture antigen (GPA) by immunofluorescence (IF). EM and IF were used to examine basement membranes (BM) in skin, lung, choroid plexus, lens, retina, and inner ear in SHG. By EM, BM in these tissues appeared similar in affected male, carrier female, and unaffected dogs. By IF, GPA could be detected only in lens capsule, internal limiting membrane of retina and basilar membrane of inner ear of unaffected and carrier female dogs, but not in affected male dogs. However, eye abnormalities and hearing loss were not present in any dogs, in contrast to their frequent occurrence in human HN. Our findings on extra-renal BM in SHG suggest that GPA is not required to maintain normal vision or hearing in affected male dogs and permit a greater understanding of the pathogenesis of human HN.
Animals↗
Typing of coagulase-negative staphylococci isolated from foreign body infections.
Twenty-six coagulase-negative staphylococci isolated from patients with various foreign body infections were characterised using different typing systems. Staphylococcus epidermidis was the most predominant species found. Phage typability was below 50% in all strains. The strains showed differences in surface properties--relative hydrophobicity or hydrophilicity--and ability to adhere to polystyrene with subsequent slime production (adherence tube test). Protein and polypeptide profiles as well as plasmid profiles demonstrated the heterogeneity of the strains. Thus, this preliminary study indicates that all coagulase-negative staphylococci of human origin may become involved in foreign body infections.
Bacterial Adhesion↗
Mechanisms and clinical relevance of bacterial adhesion to polymers.
The mechanisms of bacterial adhesion to polymers with regard to their significance in the development of foreign-body infections are discussed. The morphological, physico-chemical and biological aspects are treated with special emphasis on the adhesion of coagulase-negative staphylococci to medical polymers. Strategies for the prevention of bacterial adhesion to biomaterials by developing antiadhesive polymers are given.
Anti-Bacterial Agents↗
Ultrastructure of megakaryocytes in the human bone marrow of patients with primary (essential) thrombocythemia.
An ultrastructural study was performed on bone marrow specimens in 10 patients (5 males/5 females, median age 53 years) with primary (essential) thrombocythemia (PTH) and an excessive elevation of the platelet count (1,625 +/- 783 x 10(9)/l). In contrast to a not severely altered neutrophilic granulo- and erythrocytopoiesis, megakaryocytes showed conspicuous large to giant forms. These were characterized by a highly lobulated nucleus containing several nucleoli and an extensive intermediate zone of the cytoplasm with many Golgi fields, numerous profiles of the so-called demarcation membrane system and an abundance of alpha-granules and some dense bodies. Our results demonstrate that ultrastructure of the megakaryocytes in PTH does not reveal gross abnormalities, but features which are compatible with an enforced thrombocytogenetic activity in accordance with the excessively elevated platelet count. Similar changes have been described in animal experiments with induced thrombocytopenia and stimulation of platelet shedding. Evaluation of thrombocytogenesis suggests that it may be mediated by a process of fragmentation with partitioning of the extensive intermediate zone into numerous prospective platelet territories followed by segregation.
Bone Marrow↗
Quantitation of anionic sites in glomerular capillary basement membranes of Samoyed dogs with hereditary glomerulopathy.
Samoyed hereditary glomerulopathy (SHG) is an X-linked dominant disease characterized by proteinuria and renal failure in affected male dogs. Electron microscopic examination of glomerular capillary basement membranes (GCBM) shows widespread multilaminar splitting of the lamina densa, identical to that in Alport's syndrome. Anionic sites in GCBM of three affected males and five unaffected dogs were labeled using polyethyleneimine to determine whether proteinuria was associated with an alteration in their number. No significant differences were noted in the number of anionic sites in the lamina rara externa, whereas small but statistically significant increases were seen in the number of sites in the lamina rara interna of affected males. In the lamina densa, affected males showed a striking increase in anionic sites, particularly in regions of GCBM which were split. Thus, although proteinuria in some glomerular diseases has been attributed to a reduction in anionic sites in GCBM, this was not so in SHG.
Animals↗
Chemical modification of polyurethanes by radiation-induced grafting.
Basic methods of radiation-induced modification of polyurethanes for biomedical applications and of their characterization are briefly described. The most important works found in literature on radiation grafting of polyurethanes are discussed. The radiation grafting of polyetherurethane films and tubings by the preswelling method using various monomers and their physico-chemical characterization are discussed in detail with respect to the antithrombogenic properties of the materials. Novel applications for radiation-modified polyurethanes as drug delivery systems or antiinfectious materials are briefly mentioned.
Biocompatible Materials↗
Samoyed hereditary glomerulopathy. Immunohistochemical staining of basement membranes of kidney for laminin, collagen type IV, fibronectin, and Goodpasture antigen, and correlation with electron microscopy of glomerular capillary basement membranes.
Recent immunofluorescence studies on the kidneys of most males with hereditary nephritis have demonstrated an absence of Goodpasture antigen (GPA) from glomerular capillary basement membranes (GCBM). In the present study, we used immunofluorescence to determine whether laminin, collagen type IV, fibronectin, and GPA could be detected in basement membranes of the kidneys of dogs with Samoyed hereditary glomerulopathy, which was previously shown to be a model for human hereditary nephritis. The results obtained were correlated with the appearance of GCBM by electron microscopy (EM). The rabbit polyclonal antibodies used (antilaminin, anti-collagen type IV, and antifibronectin) showed specificity for the appropriate antigens in a plate-binding radioimmunoassay. Serum from a patient with Goodpasture syndrome was used to detect the GPA component of dog GCBM. Laminin and collagen type IV were present in GCBM, mesangium, tubular basement membrane, vascular basement membrane, and Bowman's capsule of neonatal, unaffected, and affected male and carrier female dogs. Fibronectin was present in mesangial, perivascular, and interstitial regions of the kidneys of all dogs and, in addition, in GCBM of neonatal, affected male, and carrier female dogs. GPA was not detected in the kidneys of neonatal dogs and its absence from GCBM correlated with their immature appearance by EM. However, a fully formed, trilaminar GCBM was observed by 3 weeks of age in unaffected, affected male, and carrier female dogs, before the detection of GPA in GCBM, which occurred at 4 weeks in unaffected and carrier female dogs, but still not in affected males. In the unaffected dogs, the presence of GPA correlated with the persistence of a fully formed trilaminar GCBM, which lasted throughout life, while in the carrier females, the presence of GPA correlated with focal areas of multilaminar splitting of GCBM by EM. In the affected male dogs, although a trilaminer GCBM was seen by 3 weeks of age, the persistent absence of GPA correlated with the eventual onset of multilaminar splitting of GCBM. These immunofluorescence and EM results suggest that GPA is not required to form a trilaminar GCBM initially but is necessary subsequently to maintain its integrity. GPA is normally present in the C terminal (NC1) domain of the collagen type IV molecule. It is hypothesized that Samoyed hereditary glomerulopathy in dogs and human hereditary nephritis result from a defect in the NC1 domain.
Animals↗
Samoyed hereditary glomerulopathy: serial, clinical and laboratory (urine, serum biochemistry and hematology) studies.
Human hereditary nephritis refers to familial glomerular diseases which may progress to renal failure. Samoyed hereditary glomerulopathy has been shown previously to be a model for hereditary nephritis. Clinical and laboratory studies were performed to follow progression to renal failure in 44 dogs in a family with Samoyed hereditary glomerulopathy. Affected males appeared healthy for their first three months but then became progressively wasted. Proteinuria was detected between two to three months of age; after five months, urine protein electrophoresis showed pre-albumin, albumin and alpha and beta globulin peaks. From three months onward, a reduced glomerular filtration rate was detected. Serum albumin decreased while amylase, urea, creatinine and phosphate increased from four to five months of age. Death from renal failure occurred by 15 months. Carrier females also became thinner and developed proteinuria between two and three months of age, but neither renal failure nor death ensured. Hence, SHG progressed rapidly in affected males but not in carrier females.
Animals↗
Mode of inheritance of Samoyed hereditary glomerulopathy: an animal model for hereditary nephritis in humans.
The pedigree of a line of Samoyed dogs with Samoyed hereditary glomerulopathy (SHG) was investigated to determine the mode of inheritance. Sixty percent of males were affected with severe renal disease that progressed to renal failure before 15 months of age. In contrast, female carriers showed less severe involvement and their disease did not progress to renal failure. This pattern is consistent with the inheritance of an X-linked dominant gene. A similar mode of inheritance has been postulated in some families with hereditary nephritis. Further similarities between SHG in dogs and hereditary nephritis in humans have been demonstrated previously in clinical and renal morphologic studies. The present study supports the view that this line of Samoyed dogs would be an appropriate model for studying the human disease.
Animals↗
In vitro response of purified ovine peripheral blood lymphocytes to phytohemagglutinin-M.
Peripheral blood was collected from three normal yearling castrated male lambs. Lymphocytes were isolated by Ficoll-Hypaque gradient centrifugation. Lymphocyte response to phytohemagglutinin was evaluated in an isotopic uptake stimulation test under varying culture conditions in order to standardize the assay. Results were analyzed as log10 counts per minute and stimulation indices. Culture conditions consisting of 2 microL (20 micrograms) phytohemagglutinin-M/culture, 1 X 10(6) cells/mL and a 72 hour incubation period were selected for use in further studies.
Animals↗
Samoyed hereditary glomerulopathy (SHG). Evolution of splitting of glomerular capillary basement membranes.
Samoyed hereditary glomerulopathy (SHG) in dogs resembles hereditary nephritis (HN) in man. Affected males and carrier females spontaneously develop proteinuria, but only males progress to renal failure. We examined the evolution of splitting of glomerular capillary basement membranes (GCBM) in affected male and carrier female dogs. At birth, examination by light microscopy (LM) in all dogs showed normal glomerular capillaries, but by electron microscopy (EM), many GCBM showed separation of endothelial from visceral epithelial cell basement membranes. By LM, glomerular capillaries of affected males appeared normal for up to 4 months, but then isolated and eventually all capillaries became thickened and split. However, by EM, a bilaminar appearance of the GCBM was seen within 1 month which evolved into multilaminar splitting that became extensive as renal failure ensued. Carrier females showed mild nonprogressive changes in GCBM. These results with SHG permitted speculation on the evolution of splitting of GCBM in human HN.
Animals↗
Subepithelial electron-dense deposits in idiopathic and lupus membranous glomerulonephropathy.
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Basement Membrane↗
Attachment of staphylococci to various synthetic polymers.
Attachment of staphylococci to different synthetic polymers used for medical purposes was studied in applying the bioluminescent technique. The number of attached bacterial cells was determined by measuring the light emission resulting from the reaction between firefly luciferase and ATP present in adhered staphylococcal cells. It was shown that staphylococci attach to synthetic polymers within a few minutes, although one hour incubation is required to reach a constant maximum value of attached cells. Ten different synthetic polymers and five Staphyloccocus epidermidis strains were investigated in our study. The relationship between surface properties of polymers and bacterial attachment was studied. Various physicochemical parameters of synthetic polymers and bacteria were determined (contact angle, surface tension). It was demonstrated that bacterial attachment decreases with decreasing contact angle and with increasing surface tension of synthetic materials. Modifications of surface charge and hydrophobicity of solid materials were also investigated. It could be proved that especially negatively charged and hydrophilic synthetic polymers show very decreased staphylococcal attachment.
Catheters, Indwelling↗
Animal model of human disease: hereditary nephritis in Samoyed dogs.
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Animals↗
Microbial colonization of prosthetic devices. V. attachment of coagulase-negative staphylococci and "slime"-production on chemically pure synthetic polymers.
On 12 different, chemically pure polymers attachment and "slime"-production of the coagulase-negative staphylococcal strain KH 11 were studied. According to their behaviour the polymers investigated could be arranged into three groups: Group 1 with good attachment of staphylococci, but missing "slime"-production; group 2 with good attachment and moderate "slime"-production; group 3 with both properties strongly developed. According to the results presented, attachment of staphylococci and "slime"-production seem to be independent of the presence of organic additives in biomaterials.
Adhesiveness↗