Protein adsorption on ex vivo catheters and polymers exposed to peritoneal dialysis effluent.

BACKGROUND: Deposition of proteins on surfaces of medical devices has been recognized to putatively relate to the process of regulation of biomaterial-associated complications by attachment of fibrin clots, eukaryotic cells, and microbes. The molecules adsorb to a varying extent, depending not only on the physicochemical properties of the biomaterial, but also on the composition of the host fluid. OBJECTIVE: Adsorption of proteins on catheters exposed both ex vivo and in vitro to dialysate of patients on peritoneal dialysis (PD) was studied. METHODS: Peritoneal dialysis effluent was collected from 5 patients with end-stage renal disease on continuous ambulatory PD. Tenckhoff catheters were obtained from 16 patients. Deposition of proteins on excised Tenckhoff catheters and tubing of different materials exposed to PD effluent in vitro was studied using 125iodine-labeled antibodies. Adhesion of Staphylococcus aureus and Staphylococcus epidermidis strains was quantified on tubing exposed to PD effluent in vitro. RESULTS: The presence of albumin, transferrin, immunoglobulin G, fibrinogen, fibronectin, von Willebrand factor, vitronectin, and thrombospondin was determined at various concentrations in PD effluent. All proteins analyzed were detected on PD catheters removed from patients. The extent of protein deposition on Tenckhoff catheters exposed to PD effluent, in vitro, rapidly reached a plateau and remained constant, as it did on polyvinyl chloride and polyethylene tubing. Adhesion of staphylococci was enhanced on Tenckhoff catheters exposed to PD effluent compared to unused PD solution. CONCLUSIONS: The data identify surface exposed proteins that may serve as adhesion sites for microbes on peritoneal catheters indwelled in patients undergoing PD.     

The costs of atopy and asthma in children: Assessment of direct costs and their determinants in a birth cohort

The aim of this study was to estimate costs accrued by the health care of children with asthma in comparison to children with atopic eczema and seasonal rhinitis and to investigate cost determinants. From the multicenter cohort study (MAS-90), we selected children with an asthma, atopic eczema and/or seasonal rhinitis diagnosis during the first 8 years of life, and overall 8-year health care utilization was estimated retrospectively by reviewing medical records. Asthma treatment (n = 76) incurs an average cost of US$ 627 per year, 44% due to hospital stays. Atopic eczema treatment (n = 91) cost on average US$ 219 and seasonal rhinitis (n = 69) US$ 57 per year. In asthma and atopic eczema, costs increase significantly with disease severity. Allergy diagnostics use accounts for only 1% of total costs. Costs for asthma and atopic eczema treatment are highest in those years when topical steroids are used for the first time, but decrease with every further year of steroid use. A remarkable 25% of asthmatic children with severe symptoms were not treated according to national guidelines, so that most steroid treatment was initiated during the first hospital stay. In the case of asthma, total direct costs increased until the 3rd year of the disease, and then decreased with further years of diagnosis, while steroid use continued to increase. These results indicate a 'learning effect' in the treatment of asthma and atopic eczema for each patient as well as considerable cost-saving potential by preventing severe asthma. Moreover, the importance of considering cost-driving factors and using cohort or longitudinal designs in cost-of-illness approaches is emphasized.     

CSF testosterone in 43 male suicide attempters.

Several studies have shown a relationship between high testosterone and violent aggressive behaviour. The general aim of this study was to gain knowledge of the importance of testosterone in suicide attempters. Testosterone in cerebrospinal fluid (CSF) was analysed in men with a recent suicide attempt, diagnostically subdivided into groups according to DSM-III-R axis I and II diagnosis and mode of suicidal behaviour. In general, our patients had lower CSF testosterone levels than aggressive violent patients in other studies. Patients with depression NOS or dysthymia showed higher CSF testosterone levels than the rest. Significant positive correlation between testosterone and irritability or a negative correlation with social desirability was found in diagnostic subgroup of patients, specifically axis II, cluster B personality disorders. The results suggest that suicide attempts may be mediated by different biological variables than aggression.     

Evaluation of Etest MBL for detection of blaIMP-1 and blaVIM-2 allele-positive clinical isolates of Pseudomonas spp. and Acinetobacter spp

The Etest MBL (AB BIODISK, Solna, Sweden) correctly differentiated all 57 isolates of Acinetobacter spp. and Pseudomonas aeruginosa with the bla(IMP-1) allele and 135 of 137 (98.5%) Acinetobacter spp. and Pseudomonas spp. isolates with the bla(VIM-2) allele. The Etest MBL was reliable for detecting the IMP-1- and VIM-2-producing Pseudomonas and Acinetobacter isolates.     

Sonic hedgehog guides commissural axons along the longitudinal axis of the spinal cord

Dorsal commissural axons in the developing spinal cord cross the floor plate, then turn rostrally and grow along the longitudinal axis, close to the floor plate. We used a subtractive hybridization approach to identify guidance cues responsible for the rostral turn in chicken embryos. One of the candidates was the morphogen Sonic hedgehog (Shh). Silencing of the gene SHH (which encodes Shh) by in ovo RNAi during commissural axon navigation demonstrated a repulsive role in post-commissural axon guidance. This effect of Shh was not mediated by Patched (Ptc) and Smoothened (Smo), the receptors that mediate effects of Shh in morphogenesis and commissural axon growth toward the floor plate. Rather, functional in vivo studies showed that the repulsive effect of Shh on postcommissural axons was mediated by Hedgehog interacting protein (Hip).     

Crystal Containing Membrane Bound Intracellular Inclusion Bodies in the Epithelium of Experimentally Infected Sinus Mucosa

The sinus mucosa of 16 rabbits was experimentally infected with Bacteroides fragilis. This paper describes and discusses large inclusion bodies, which were found in abundance by light and electron microscopy inside ciliated cells of the sinus epithelium in 3 of the studied animals. The spindle-shaped inclusions were located in the apical portion of the cytoplasm. They were bound by a trilaminar membrane with several coils to the interior as well as to the exterior. The interior of an inclusion body consisted to a large extent of electron-lucent, floccular substance, but fibrogranular aggregates and rod-shaped crystals with a line periodicity center-to-center of about 15 nm were also conspicuous. These peculiar formations may be constituted by abnormally stored material from defective synthesis of cilia.     

Mothers' management of childhood diseases in Yorubaland: the influence of cultural beliefs

Several studies have noted that, besides inadequate availability of health care services in many areas, especially the less developed countries, certain disease-specific and non-disease-specific cultural beliefs may influence people's health seeking behaviour. It has even been noted that health services may be underutilized and several health and child care instructions may be ineffective or ignored in traditional and transitional societies where people's ideas and behavioural patterns conflict with the knowledge being passed to them (Feyisetan and Adeokun 1992; Feyisetan 1992). Feyisetan and Adeokun (1992) argued that non-adoption of modern preventive and curative measures cannot be attributed to poverty alone since the costs of some preventive and curative measures are not exorbitant in several of these societies. Rather, they suggested that the gap between awareness of modern health measures and health seeking behaviour must be sought in the social and cultural determinants of behaviour in such matters as child care and disease management. Earlier studies have noted that children in Nigeria die mainly from malaria, diarrhoea, measles, neonatal tetanus, whooping cough, tuberculosis, and bronchopneumonia (Morley and MacWilliam 1961; Ogunlesi 1961; Morley, Woodland and Martin 1963, 1966; Baxter-Grillo and Leshi 1964; Animashaun 1977; Tomkins 1981). Because these diseases are preventable at low cost to the individual, there is a need to investigate why large percentages of children are still subjected to many episodes of these diseases. In this paper, we examine (1) the mothers' perceptions of the aetiology of the three most cited childhood diseases in our study areas, measles, diarrhoea and fever, and the effect of these perceptions on the mothers' suggested curative measures; and (2) the persistence of the belief in abiku and how this cultural belief can influence mothers' management of childhood diseases. Since, for most mothers, perceptions of the aetiology of the childhood diseases are rooted in cultural beliefs, a brief review of disease-specific cultural beliefs is undertaken. In order to determine the effect of socio-economic factors, the mothers' perceptions of the aetiology of the childhood diseases, their recommended curative measures and the belief in abiku are examined according to selected socio-economic variables.     

HLA-D Antigen Expression and Langerhans' Cell Infiltrates in Thyroid Tumors

Papillary carcinomas (PCs) of thyroid are among the most common but least aggressive human malignancies. The factors explaining the indolence of these tumors are unknown but host-tumor immune interactions may play a role. This study was designed to determine if there is morphologic evidence of these. Frozen tissues collected from 21 PCs, 4 follicular adenomas (FAs), 4 follicular carcinomas (FCs), and 11 nodular hyperplasias (NHs) were stained immunohistochemically for HLA-D antigens, lymphocyte and macrophage markers; results were graded numerically. Paraffin-embedded tumors (35 PCs, 10 FAs, and 10 FCs) were stained for S-100 protein to detect Langerhans' cells (LCs). Diffuse staining for HLA-D antigens and heavy mononuclear infiltrates were found more commonly in PCs compared to follicular neoplasms (FNs) or NHs. No consistent relationship was found between lymphocyte/macrophage infiltrates and expression of HLA-D antigens. The largest number of LCs was in PCs (median 11.8 cells/standard microscopic field [c/smf]), fewer cells were found in FA (3.7 c/smf), and the least in FC (0.05 c/smf). Features of host-tumor interaction including HLA-D expression and infiltrates with lymphocyte macrophages and LC are more strongly expressed in PC than other tumors. This may play a role in explaining their biological behavior.