Search PubMed⌕ Search

Biomedical subjects

W Samtleben

Publications and source records attributed to W Samtleben.

At least 55 records · Page 3Linked to original sources
PubMed1993

Renal complications of infected ventriculoatrial shunts.

Contamination of a ventriculoatrial shunt (VAS) with skin organisms that are usually nonpathogenic may be followed by an immunologically mediated renal injury. The bacteria characteristically involved are coagulase-negative Staphylococci (e.g., Staphylococcus epidermidis), which strongly adhere to the plastic surface of the VAS. These bacteria are protected from the body's natural defense mechanisms and respond only poorly to antibiotics. As a result, their growth persists and produces a continuous antigenic stimulation. Circulating immune complexes (CIC) are an appropriate tool to screen for chronically infected VASs. We followed CIC in 138 VAS patients. An infected VAS was seen in 20 of the 24 patients with highly elevated CIC and in 1 of the 19 patients with moderately elevated CIC, but none of the 95 patients with normal CIC had evidence of shunt infection. Of the 21 patients with shunt infections, 8 had renal involvement (4 requiring dialysis, and 4 with proteinuria, hematuria, and/or elevated creatinine). Results from kidney biopsy specimens available from 4 patients confirmed glomerulonephritis. Of the 4 patients requiring dialysis at diagnosis, renal function recovered sufficiently to stop dialysis after successful VAS exchange in all but 1. In the other 4 patients, renal symptoms (proteinuria, creatinine) also improved after VAS revision. Chronic infection with S. epidermidis or other bacteria is a continuing problem in patients with VASs and can lead to an immune-mediated renal injury. However, the prognosis for reversal of the renal injury is relatively good if the VAS infection is treated promptly.

Adolescent↗
PubMed1993

Reverse flux filtration: a new mode of therapy improving the efficacy of heparin-induced extracorporeal LDL precipitation in hyperlipidemic hemodialysis patients.

In the steady state after a run-in phase of 3 months, the acute effects of 3 modifications of weekly heparin-induced extracorporeal LDL precipitation (HELP) were studied in 5 ESRD and 2 non-uremic hypercholesterolemic coronary patients. In ESRD patients (n = 29 sessions), HELP reduced LDL-cholesterol (LDL-C) (56 +/- 7%) and fibrinogen (FIB) (54 +/- 10%) by a similar percentage as compared to non-uremic controls (60 +/- 4% and 61 +/- 3%, resp.; n = 5). In order to eliminate the need for extra HELP sessions in addition to the normal dialysis regimen, newly developed hardware was then used to perform combined synchronous HELP/HD (n = 12). However, premature precipitate filter plugging probably due to hyperfibrinogenemia in ESRD patients, accentuated by ultrafiltration (UF), decreased the corresponding reductions to 26 +/- 9% (LDL-C) and 34 +/- 11% (FIB). Therefore, the procedure was modified by reversing the filtrate flux through the precipitate filter membrane after 900 ml of treated plasma ("reverse flux filtration", RFF; n = 11). Thus, in RFF-HELP/HD the LDL/FIB/heparin coprecipitate was deposited on both filter membrane sides which caused a significant enhancement of the filter capacity and improved reductions to 46 +/- 14% for LDL-C and 51 +/- 15% for FIB. Elution of the precipitate from the precipitate filter after the sessions showed that RFF-HELP/HD had trapped 1733 +/- 238 mg LDL-C and 8108 +/- 1876 mg FIB in ESRD patients, while HELP eliminated 1890 +/- 333 mg LDL-C and only 3663 +/- 369 mg FIB in non-uremics. Filter precipitate recoveries (relative to the mass removed from the patient plasma pool) amounted to 97 +/- 18% for LDL-C and 158 +/- 67% for FIB in the ESRD group treated by RFF-HELP/HD vs. 70 and 76% in the non-uremic HELP group. Probably, passive transport of lipoproteins and FIB from the interstitium into the vascular space caused repletion of this compartment during HELP/HD where an UF induced solvent drag is effective. In summary, the new RFF-HELP/HD procedure effectively reduced LDL-C and FIB in ESRD patients who could not be adequately treated by the conventional HELP/HD system.

Blood Component Removal↗
PubMed1992

[Interstitial lupus nephritis].

A 17-year old-male presented with a 6-week history of weight loss, lassitude and calf pains. On examination he was very pale. Laboratory tests showed a very high erythrocyte sedimentation rate (155 mm in the first hour), anaemia (haemoglobin 10.1 g/dl), and a raised serum creatinine of 1.54 mg/dl. Microhaematuria (5-10 erythrocytes/microliter) and pronounced pyuria (500 leucocytes/microliter) were present, but the urine was sterile and there was no increase in albumin excretion. The serum IgG was raised to 75.7 g/l, suggesting an autoimmune disorder. Anti-nuclear antibodies (titre 1 : 1920) and anti-double-stranded DNA antibodies (31 U/ml) were present, while the serum complement C4 was decreased to 0.11 g/l. Renal histology showed an interstitial nephritis without glomerular involvement, while the bone marrow showed vasculitis accompanied by a prominent plasma-cell infiltrate. A diagnosis of interstitial nephritis associated with systemic lupus erythematosus was made, with asymptomatic cardiac and hepatic involvement. Renal function recovered rapidly with prednisolone therapy (initial dose 2 mg/kg.d). While glomerulonephritis is the most common lupus-associated renal disorder, isolated interstitial nephritis may occur in some cases, often with an absence of proteinuria.

Adolescent↗
PubMed1992

Adsorption profile of commercially available adsorbents: an in vitro evaluation.

Adsorbents from four commercially available devices, Protein A-Sepharose (Immunosorba Protein A-62,5; Excorim KB, Lund Sweden), Tryptophan-PVA (Immusorba TR-350; Asahi Medical Co., Tokyo, Japan), Phenylalanine-PVA (Immusorba PH-350; Asahi Medical Co., Tokyo, Japan), and Dextran sulfate (Liposorber LA-15; Kanegafuchi Chemical Co. Ltd, Osaka, Japan) were tested under optimal in vitro conditions to determine their adsorption capability for several plasma constituents which are usually the target of plasma therapy. The parameters of interest were: double stranded DNA-antibodies (anti-dsDNA), antiglomerular basement membrane antibodies (anti-GBM), anti-acetylcholin receptor antibodies (AChRAb), circulating immune complexes (CIC), rheumatoid factor (RF), IgA, IgG, IgM, IgE, C3c, C4, LDL-cholesterol, total cholesterol, erythropoietin (EPO) and beta 2-microglobulin (beta 2M). The IgG auto antibodies, CIC and RF can be removed by Protein A-Sepharose, Try-PVA and Phe-PVA. IgG is best adsorbed by Protein A-Sepharose, while IgE can be removed efficiently by Try-PVA. Dextran sulfate is without doubt the best adsorbent for LDL-cholesterol. All four adsorbents bind also complement components C3c and C4. No significant adsorption was found for EPO and beta 2M. The four devices exhibit a quite different adsorption profile which can be used as a guide for the optimal selection of an adsorption column in clinical apheresis.

Adsorption↗
PubMed1991

[MRT in dialysis-associated destructive spondylarthropathy of the atlantoaxial region].

Destructive bone and joint diseases in patients on longterm haemodialysis increase in frequency and are often caused by beta 2-microglobulin-related amyloid deposits. Due to the excellent visualisation of amyloid, MRI with T1-weighted and out-of-phase gradient recalled long TR images is the diagnostic modality of choice. 5 patients, 13 to 21 years on haemodialysis, were investigated. In four patients we found involvement of the atlantoaxial region, one patient was asymptomatic, the other three had severe neurological deficiencies.

Adult↗
PubMed1989

Recombinant human erythropoietin in nephrology.

rEPO therapy provides a unique opportunity to correct anemia in end-stage renal failure patients. Complete correction of the anemia, although possible, has some obvious disadvantages over a partial correction with a target hemoglobin of 10-13 g/dl or a hematocrit of 30-35%, respectively. Unresponsiveness to rEPO seems to be rare; in most cases the predicted hemoglobin increase could be seen as soon as an underlying iron deficiency was treated adequately. Blood loss and aluminum toxicity are the next most frequent reasons for an inadequate response to rEPO. Hypertension (and its complications) as well as fistula clotting are the most important side-effects which require close attention when patients at risk for these complications are treated with rEPO.

Acute Kidney Injury↗