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Biomedical subjects

E Ritz

Publications and source records attributed to E Ritz.

At least 757 records · Page 42Linked to original sources
PubMed1984

Bone mineral content after renal transplantation. Placebo-controlled prospective study with 1,25-dihydroxy vitamin D3.

Forearm bone mineral content (BMC), as evaluated by photonabsorption densitometry, was measured in 28 cadaver kidney donor recipients who entered the study 8 weeks postoperatively and were followed up for 18 months. BMC decreased significantly (p less than 0.05) but marginally in placebo-treated patients (n = 14) (initial BMC 1.09 +/- 0.25 g/cm; final BMC 1.05 +/- 0.24). Fourteen patients were prophylactically given 1,25(OH)2 vitamin D3 in a dose which avoided hypercalcemia and hypercalciuria (approximately 0.25 microgram/day); under 1,25(OH)2 vitamin D3 prophylaxis a significant decrease of forearm BMC was observed no longer (initial BMC 0.94 +/- 0.21 g/cm; final BMC 0.95 +/- 0.21), but the difference between placebo and 1,25(OH)2 vitamin D3 narrowly missed statistical significance (p = 0.066). It is concluded that the decrease of forearm BMC is negligible in transplant recipients with low steroid regimens. The data suggest a trend for prophylaxis with 1,25(OH)2 vitamin D3 to slightly ameliorate forearm (cortical) BMC loss.

Adult↗
PubMed1984

Plastic filing from dialysis tubing induces prostanoid release from macrophages.

Multiorgan, abnormalities in dialysis patients (for example, hepatosplenomegaly, granulomatous hepatitis, cytopenia from hypersplenism) have recently been ascribed to the loading of macrophages (MO) with silicone particles released from the pump segment of dialysis tubing. In the present study, the effect of chronic intravenous or intraperitoneal loading of rats with silicone, polyvinylchloride (PVC) and polyurethane (PU) particles on arachidonic acid metabolism of peritoneal MO and splenic cells was examined in vitro. Intravenous injections of silicone, PVC, or PU particles caused accumulation of the material within the lysosomes of MO of spleen, liver, and lung. Spontaneous release of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) was significantly increased in peritoneal MO of rats injected with silicone, PVC, or PU (Control: 4.27 +/- 0.85 ng PGE2/ml/24 hr; silicone 51.9 +/- 13.2; PVC 57.5 +/- 10.6; PU 28.8 +/- 2.3). Zymosan or LPS stimulated PGE2 release from control MO, but caused no consistent further elevation of high basal PGE2 release from MO after particle loading. Furthermore, increased spontaneous and stimulated TXB2 release was also observed in spleen cells of rats given intravenous injection of silicone particles. It is concluded that storage of plastic particles (silicone, PVC, and PU) by macrophages stimulates arachidonic acid metabolism.

Animals↗
PubMed1984

Do antibody-coated bacteria reflect local immune response in the urinary tract?

We examined whether antibody-coated bacteria (ACB) reflect local immune response or passive adsorption of immune globulins (Ig). For this purpose, bacterial subcultures from infected urines and third-party bacteria were incubated with Ig preparations. These were obtained from infected urine either by removal of Ig from ACB (dissociation in alpha-methylmannoside, 0.1 M glycine-HCl, or 3 M NaSCN) or by staphylococcal protein A affinity chromatography from the supernatant of infected urine. Coincubation of either Ig preparation with bacterial substrains of the original urine and with third-party strains (Pseudomonas aeruginosa, Proteus mirabilis, several Escherichia coli strains, enterococci, Serratia marcescens, Klebsiella pneumoniae, Staphylococcus aureus) caused coating of the bacterial surface with Ig. Coating was not measurably influenced by coincubation with various carbohydrates or by preincubation of bacteria with glucosidases. Adsorption of Ig was observed after heat denaturation and formalin treatment of bacteria and was independent of bacterial growth phase. Coating was observed both with intact IgG and with F(ab)2 fragments. We further examined the proportion of bacteria coated with IgA, IgG, and IgM in urines of 200 bacteriuric women with symptomatic urinary tract infection. The frequency histogram plot showed a continuous nonlinear unimodal distribution. Consequently, any selection of a 'normal range' is arbitrary. It is concluded that coating of the bacterial surface with Ig may not necessarily reflect local immune response. A major problem of the ACB test is definition of the normal range.

Antibody-Coated Bacteria Test, Urinary↗
PubMed1984

Multicystic transformation of kidneys in chronic renal failure.

With real-time sonography, 120 nondialyzed uremic patients prior to hemodialysis, 108 patients on maintenance hemodialysis and 9 patients postdialysis after successful homotransplantation were examined for the presence of renal cysts. Even in incipient renal failure, multiple cysts were demonstrable in some patients (at a serum creatinine of 3 mg/dl in 22% of patients), particularly in patients with analgesic nephropathy. When hemodialysis was started (serum creatinine approximately 10 mg/dl), 35% of the patients had multiple cysts. On hemodialysis, the prevalence, number and size of cysts rose progressively with time. After 8 years of hemodialysis, 92% of the patients had multiple cysts. However, enlargement of the kidneys was observed in only 2/108 patients. No major clinical complications were noted with the possible exception of 1 case of renal cell carcinoma. No correlation was noted between hematocrit and presence or extent of cystic transformation, but the 2 patients with cystic enlargement of the kidneys were polyglobulic. In 8/9 patients after transplantation, cysts were demonstrable in the patient's own kidneys after a median follow-up of 16 months. On light microscopy, cysts were lined by cuboidal or columnar epithelial cells with frequent papillary or adenomatous proliferations. The cyst lumen was filled with amorphous or lamellated organic material, which exhibited microfibrillar structure on electron microscopy. One kidney examined after ex vivo perfusion fixation showed multiple interconnected cavities on scanning electron microscopy. Ultrastructural studies showed epithelia with either the characteristics of proximal tubular cells (i.e. numerous microvilli, interdigitations and abundant lysosomes or mitochondria) or distal tubular cells (i.e. highly interdigitating processes) or finally collecting duct cells (i.e. no interdigitations and few microvilli).

Acute Kidney Injury↗