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Since the bacterial ability to develop resistance against various factors of their surroundings is a well-known phenomenon, resistance against iodine and specifically against povidone-iodine (PVP-I) has been widely investigated. Yet there is little known about bacterial resistance in long-term daily use of disinfectants in continuous ambulatory peritoneal dialysis (CAPD) patients. The aim of our study was to investigate whether on daily use of PVP-I over a period of at least 6 months coagulase-negative staphylococci (CNS)--the predominant infective organisms of peritonitis--developed resistance against PVP-I. At the catheter exit site of 40 CAPD patients we isolated 36 CNS. 23 CNS (CNS + PVP) orginate from patients using PVP-I, 13 CNS (CNS + CI) from patients using sodium hypochlorite (NaOCl) as disinfectant. The strains were biotyped, antibiotic resistance patterns were determined and resistance against PVP-I or NaOCl was calculated as reduction factor using the quantitative suspension test combined with a turbidimetric standardization. Resistance against PVP-I 0.01% and against NaOCl 0.005% was determined at two contact times (30 and 300 s) for each patient group. In addition, we investigated the effects of plasmid loss on sensitivity to PVP-I. Out of 5 multiple-antibiotic-resistant CNS, 3 strains showed no difference in reduction factor against PVP-I before and after curing. There was no significant difference in reduction factor against NaOCl. CNS + PVP were even significantly more sensitive to PVP-I than CNS + Cl. Taken together, our results demonstrate that long-term use of PVP-I does not cause any bacterial resistance in CNS of CAPD patients.

Recently, the ligand for c-mpl has been identified and cloned. Initial studies of this molecule indicate that it is the platelet regulatory factor, thrombopoietin (TPO). Previous work has indicated that c-mpl is expressed in very immature hematopoietic precursors and thus raised the possibility that TPO may act directly on the hematopoietic stem cell. Therefore, in these studies, we investigate the effects of TPO on hematopoietic stem cell populations isolated from the murine fetal liver and bone marrow. Cocultivation of stem cells with fetal liver stroma give rise to multilineage expansion of the stem cells but with little or no megakaryocytopoiesis. Addition of TPO to these cocultures gives significant megakaryocyte production. This production is enhanced in combination with Kit ligand or interleukin-3. The addition of TPO to stem cell suspension cultures produces a dynamic thrombopoietic system in which stem cells undergo differentiation to produce megakaryocytes and proplatelets. These experiments show that the megakaryocytopoietic and thrombopoietic activities of TPO are initiated at the level of an early progenitor cell or upon the hematopoietic stem cell.

The effect of pre- and postnatal lead ingestion on choline acetyltransferase (ChAT) activity, muscarinic cholinergic receptors (mACHR) and on nest odor preference, was investigated in the early postnatal male rat. Long Evans dams were given either 0.15% [LL = low lead] or 0.25% [ML = moderate lead] lead acetate (controls, 0.125% or 0.075% sodium acetate) in their drinking solution from the first day of pregnancy and during lactation. Mean blood lead levels were 55 micrograms/100ml at postnatal day [PN] 6 in ML-treated offspring and 35 micrograms/100ml at PN 9 in LL-treated pups. General health of pups and dams was not affected. Lead-treated offspring showed a reduced preference for or ability to identify the smell of home bedding, when tested at PN 9. A decrease in binding (Bmax) of [3H]N-methyl- scopolamine (NMS) was detected in olfactory bulb and in visual cortex of LL-treated rats at PN 9; the affinity (KD) was unchanged. On the other hand, ChAT-activity of ML-treated offspring was significantly increased in olfactory bulb at PN 6. These results suggest that stage-specific behaviors depending on sensory functions and cholinergic projection systems in related brain areas are sensitive to pre- and postnatal lead exposure.

Patient isolation aims at reducing the risk of infection transmission to other patients and the hospital personnel. Three types of disease-specific isolation procedures and their indications are described: strict isolation, respiratory isolation and enteral isolation. The type of patient isolation to be applied depends on the mode of pathogen transmission and on the severity of the disease it produces.

For years hygiene rituals have been performed in hospitals without awareness of their sense or usefulness. The present study sets out to show that entrance mats with tacky or disinfectant surfaces, complete disinfection of the hospital and routine general disinfections can be dispensed with. Shortcomings in surgical hand disinfection, placing and care of drains, and rinsing of stomach probes are also pointed out. Modern proposals should be aimed at raising the standard of hygiene in our hospitals, with special emphasis on the time-honoured rule of Semmelweis regarding strict and permanently available hygienic disinfection for the hands.