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H van Bronswijk

Publications and source records attributed to H van Bronswijk.

32 records · Page 2Linked to original sources
PubMed1989

Are intracellularly penetrating antibiotics warranted in CAPD-related peritonitis?

Survival and growth of bacteria within peritoneal macrophages has been implicated as causes of recurrences and relapses of Staphylococcus epidermidis peritonitis. We compared the effect of cephradine--known not to penetrate into peritoneal macrophages--with that of clindamycin--known to concentrate in phagocytes--on the intracellular killing of S. epidermidis by human peritoneal macrophages. Clindamycine (q.i.d. 300 mg) or cephradine (q.i.d. 250 mg) was taken orally for one day in a randomized cross-over setting by 8 stable CAPD patients. On both days peritoneal macrophages were isolated from the overnight effluents and their capacity to phagocytize and kill S. epidermidis was measured. Phagocytes isolated from and incubated in effluents containing clindamycin, showed better bacterial uptake (32 vs 17%, p less than 0.01) and killing (70 vs 42%, p less than 0.01) compared to cephradine. Moreover, clindamycin prevented S. epidermidis to multiply intracellularly (-0.33 decrease in log colony forming units (cfu)/ml after 18 h). In sharp contrast, phagocytes incubated with cephradine allowed S. epidermidis to increase over 18 h (+1.48 increase in log cfu/ml; p less than 0.01 compared to clindamycin). We conclude that antibiotics with the ability to suppress intracellular bacterial growth may provide a more optimal treatment of CAPD-related peritonitis.

Administration, Oral↗
PubMed1989

Heterogeneity in opsonic requirements of Staphylococcus epidermidis: relative importance of surface hydrophobicity, capsules and slime.

The opsonic requirements of 65 strains of Staphylococcus epidermidis were compared in fresh and in heated normal human serum. The strains were isolated from patients with CAPD peritonitis (n = 26), neonatal septicaemia (n = 24) and nasal cultures (n = 15). A wide variation was observed in opsonic requirements between the different strains, both with fresh and with heated serum. Opsonization in heated serum proceeded less efficiently and higher concentrations (mean three-fold compared to fresh serum) were needed for adequate phagocytosis. However, a highly significant correlation was found between the minimal opsonic concentrations of fresh and of heated serum (r = 0.84, P less than 0.0005). In addition, S. epidermidis can become opsonized in agammaglobulinaemic serum. Thus, opsonization of S. epidermidis can be mediated by antibodies alone and by complement alone. Slime-producing strains and encapsulated strains did not require higher concentrations of serum to become opsonized. Opsonic requirements were highly significantly correlated with surface hydrophobicity. Enzymatic treatment rendered the strains more hydrophilic and decreased their opsonic requirements. Isolates from nasal cultures required significantly higher concentrations of both fresh and heated serum to become adequately phagocytozed, whereas isolates from CAPD peritonitis required higher concentrations of heated serum only compared to blood isolates. The uptake of S. epidermidis preopsonized in heated serum as determined in our direct phagocytosis assay did not result in a comparable chemiluminescence response.

Antibodies, Bacterial↗
PubMed1988

Distinct subpopulations of elicited human macrophages in peritoneal dialysis patients and women undergoing laparoscopy: a study on peroxidatic activity.

The endogenous peroxidatic activity (PA) pattern of peritoneal macrophages from 24 continuous ambulatory peritoneal dialysis (CAPD) patients and from five healthy women undergoing laparoscopy was studied. In general, the macrophages showed two different PA patterns in vivo: exudate and negative macrophages. However, two of 24 CAPD patients showed resident macrophages, the first described in vivo in man. Since, in general, the examined human peritoneal macrophages are exudate and PA-negative, this suggests, in accordance with the animal model system, that a chronic sterile inflammation exists in the peritoneal cavity of CAPD patients and healthy women undergoing laparoscopy. After 2 hr culture, blood monocytes and peritoneal macrophages transformed into cells with the characteristics of exudate-resident and resident macrophages, so isolation procedures that include short periods of culture can change the developmental stage of human monocytes and macrophages.

Female↗
PubMed1988

Dialysis fluids and local host resistance in patients on continuous ambulatory peritoneal dialysis.

The ability of polymorphonuclear leukocytes, monocytes and peritoneal macrophages to mount a respiratory burst in continuous ambulatory peritoneal dialysis (CAPD) fluids was tested in a phorbol-myristate acetate stimulated chemiluminescence assay. Fresh CAPD fluids depressed the chemiluminescence response of all three types of phagocytes tested to less than 18% of their chemiluminescence response in control buffer. When tested in spent CAPD fluids the suppression of chemiluminescence was 30-32%. Oxygen consumption of polymorphonuclear leukocytes was depressed in fresh CAPD fluids to below 40%. Both phagocytosis of Escherichia coli by and bactericidal capacity of polymorphonuclear leukocytes and monocytes were suppressed in fresh CAPD fluids but not in spent effluents. The influence of acidic pH and hyperosmolality on phagocytic functions were studied separately by modifying the acidity or the glucose content of the control buffer. pH values below 6.0 significantly inhibited chemiluminescence but not phagocytosis. Under hypertonic conditions, both phagocytosis and chemiluminescence were inhibited. We conclude that the currently available CAPD solutions are beyond the limits of acid and osmotic tolerance of human phagocytic cells, and may thus compromise the peritoneal defenses of CAPD patients.

Escherichia coli↗
PubMed1987

The effect of fish oil on lipid profile and viscosity of erythrocyte suspensions in CAPD patients.

In this study we investigated the effects of a daily supplementation of 6 g Super-EPA containing 3 g of the marine fatty acids eicosapentaenoic acid (EPA, C 20:5 omega-3) and docosahexaenoic acid (DHA, C 22:6 omega-3) for a period of 8 weeks in nine patients on continuous ambulatory peritoneal dialysis. The concentrations of both HDL2 cholesterol and total HDL cholesterol increased (P less than 0.05) and there was a marked reduction in triglycerides (P less than 0.05). The viscosity of erythrocyte suspensions at a haematocrit of 0.80 decreased at most shear rates, suggesting an increased erythrocyte deformability. Mean corpuscular volume decreased (P less than 0.05) and total cholesterol and phospholipids in the erythrocyte membrane increased. We conclude that the daily use of 3 g of omega-3 polyunsaturated fatty acids by CAPD patients produces favourable effects on lipid profile and viscosity of erythrocyte suspensions, which may be of importance in protecting these patients against a further progression of atherosclerosis.

Blood Viscosity↗
PubMed1987

Long-term use of magnesium hydroxide as a phosphate binder in patients on hemodialysis.

The long-term use of magnesium hydroxide [Mg(OH)2] as a phosphate binder was investigated in 18 patients on chronic hemodialysis. All patients received a basal treatment with oral calcium carbonate. Vitamin D supplements were not used. In period I each patient ingested aluminum hydroxide [Al(OH)3], in period II Mg(OH)2 and in period III Mg(OH)2 and Al(OH)3 together. During period II and III a dialysate devoid of Mg was used. Mg(OH)2 doses were adjusted to prevent severe hypermagnesemia and diarrhea. The mean dose of Mg(OH)2 in period II was 2.4 +/- 0.6 and in period III 2.6 +/- 1.2 g/day. Serum phosphate increased significantly in period II and fell again in period III. Despite a halving of the Al(OH)3 dose in period III, serum Al was similar in period I and period III (55.8 +/- 19.1 vs 57.1 +/- 27.3 microg/l). Parathyroid hormone (PTH) concentration fell in period II and decreased even further in period III. We conclude that oral Mg(OH)2 may reduce the required Al(OH)3 dose, however, without an effect on serum Al concentration. The observed suppression of parathyroid activity needs further study.

Aluminum Hydroxide↗
PubMed1983

Use of a new heparinoid as anticoagulant during acute haemodialysis of patients with bleeding complications.

Org 10172, a new, natural heparinoid, was used as the sole anticoagulant in twelve patients with acute or acute-on-chronic renal failure, who underwent haemodialysis 55 times. All patients had either intercurrent bleeding or a high risk of severe haemorrhagic complications if given standard heparin therapy. After a single loading dose of 300-600 mg of Org 10172, plasma anti-Xa levels in the range 0.42 - 0.93 U/ml were achieved. All haemodialysis runs were completed without adverse side-effects. There were no haemorrhagic complications and deposition of 125I-fibrinogen on the renal dialysis membrane was successfully inhibited in the 4 patients in whom this was studied. Org 10172 seems to prevent thrombosis during renal haemodialysis. It may have a lower risk/benefit ratio than other anticoagulants, such as heparin, in patients at high risk of haemorrhagic complications undergoing haemodialysis.

Acute Kidney Injury↗