Patients hospitalized abroad as importers of multiresistant bacteria-a cross-sectional study.

OBJECTIVES: The pandemic spread of multidrug-resistant (MDR) bacteria poses a threat to healthcare worldwide, with highest prevalence in indigent regions of the (sub)tropics. As hospitalization constitutes a major risk factor for colonization, infection control management in low-prevalence countries urgently needs background data on patients hospitalized abroad. METHODS: We collected data on 1122 patients who, after hospitalization abroad, were treated at the Helsinki University Hospital between 2010 and 2013. They were screened for methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE), vancomycin-resistant enterococci, carbapenemase-producing Enterobacteriaceae (CPE), multiresistant Pseudomonas aeruginosa and multiresistant Acinetobacter baumannii. Risk factors for colonization were explored by multivariate analysis. RESULTS: MDR colonization rates were higher for those hospitalized in the (sub)tropics (55%; 208/377) compared with temperate zones (17%; 125/745). For ESBL-PE the percentages were 50% (190/377) versus 12% (92/745), CPE 3.2% (12/377) versus 0.4% (3/745) and MRSA 6.6% (25/377) versus 2.4% (18/745). Colonization rates proved highest in those returning from South Asia (77.6%; 38/49), followed by those having visited Latin America (60%; 9/16), Africa (60%; 15/25) and East and Southeast Asia (52.5%; 94/179). Destination, interhospital transfer, short time interval to hospitalization, young age, surgical intervention, residence abroad, visiting friends and relatives, and antimicrobial use proved independent risk factors for colonization. CONCLUSIONS: Post-hospitalization colonization rates proved higher in the (sub)tropics than elsewhere; 11% (38/333) of carriers developed an MDR infection. We identified several independent risk factors for contracting MDR bacteria. The data provide a basis for infection control guidelines in low-prevalence countries.

Effects of lactide monomer on the hydrolytic degradation of poly(lactide-co-glycolide) 85L/15G.

The hydrolytic degradation of oriented poly(L-lactide-co-glycolide) 85 L/15 G (PLGA 85/15) sample materials with various amounts of lactide monomer was monitored in vitro at 37 °C. The materials were manufactured from medical grade PLGA 85/15 by a two-step melt extrusion-die drawing process. Results showed that the hydrolytic degradation rate depended highly on the lactide monomer content, which in turn influenced the retention of mechanical properties, mass loss, crystallinity, and dimensional stability. Even small quantities of lactide monomer (0.05-0.20 wt%) affected especially the retention of mechanical properties, which started to decline rapidly upon the inherent viscosity reaching 0.6-0.8 dl/g due to hydrolytic degradation. Based on our hydrolytic degradation data, we constructed a simplified mathematical model of degradation-related strength retention and recommend it as a functional quality control tool for melt-processed biodegradable medical devices manufactured from poly(L-lactide-co-glycolide) 85 L/15 G.

Region of interest sensitivity ratio in analyzing sensitivity distributions of electrocardiographic measurements.

Modern devices such as wearable and implantable systems provide new methods for bioelectric measurement while creating new needs to assess the efficacy of the measurements. A modeling related analysis method, called the region of interest sensitivity ratio (ROISR), has been developed and applied hitherto in analyzing EEG measurements. ROISR describes how well the sensitivity of a measurement is concentrated within the region of interest (ROI). The objectives of the present study were to demonstrate and evaluate the applicability of this method in analyzing the specificity of ECG leads and to compare the results with those previously published. Here the specificities of the 117 leads of a Dalhousie body surface ECG mapping system to different segments of the left ventricular myocardium and the whole right ventricular free wall were analyzed. The ROISR method was also validated with epicardial dipole simulations. The results are consistent with those from previous clinical studies, and the ROISR method is thus applicable in future studies where, e.g., sensitivity distributions of implantable ECG measurements are analyzed.

Social interactions in Red Junglefowl (Gallus gallus) and White Leghorn layers in stable groups and after re-grouping.

Although social behaviour is a major factor affecting the coping of poultry in production environments little is known about how it has been affected by intensive selection processes in fowl. We attempted to clarify selection effects on overall repertoire and occurrence of different social behaviours as well as on aggressive responses to re-grouping with unfamiliar birds by comparing high-producing White Leghorn layers to wild type Red Junglefowl. In the first experiment we observed 8 stable mixed sex groups/breed each consisting of four 24-week-old birds previously familiar to each other. During 9 consecutive days, a wide range of social signals, sexual and aggressive interactions as well as spacing behaviour and activity were recorded over a 12-h photoperiod. In the second experiment, starting at 19 weeks of age, 16 single sex groups of three birds from each breed were formed by mixing unfamiliar individuals. Aggressive behaviours were recorded 0, 5, 24 and 48 h after re-grouping. Results from the stable groups indicated that the repertoire of social behaviours has been preserved during selection with few changes in frequencies and intensities. However, Leghorns showed a more cohesive spacing pattern than junglefowl. In the second experiment, aggressive activity was higher immediately and after 24 h following re-grouping in Leghorns, but there was a drop in the aggressiveness at 5 h to the same level as junglefowl. We suggest that this may indicate poorer social learning capacity with a weaker ability to cope with group disruptions compared to the ancestral breed.

Responses of young red jungle fowl (Gallus gallus) and White Leghorn layers to familiar and unfamiliar social stimuli.

Social preferences of familiar over unfamiliar social stimuli in chicks may be used to measure sociality, a characteristic important for the welfare of poultry in commercial production. We studied social preferences and reaction to strangers in young White Leghorns and red jungle fowl (Gallus gallus) in 3 tests. All chicks were raised and housed in 2 groups of 34 individuals per breed. At 24 to 29 d of age 38 chicks per breed were tested in 2 runway tests. In the first, chicks had a free choice between familiar and unfamiliar breed members, and in the second the choice was between unfamiliar chicks of their own breed and the other breed. On d 41 to 42, spacing and agonistic interactions of 28 pairs of chicks per breed (in half of the pairs, chicks were unfamiliar to each other) were observed in an open field for 10 min (pair test). In the first runway test, clear preference for familiar chicks and avoidance of unfamiliar social stimuli was found only in Leghorns, whereas both breeds showed a preference for their own breed members in the second runway test. Affiliation to the familiar breed, however, was more pronounced in Leghorns. In the pair test, Leghorns were significantly more involved in agonistic interactions than wild-type chicks. Avoidance of unfamiliar and preference for familiar conspecifics might suggest a weaker capacity of Leghorns to cope with novel social and environmental stimuli, which might have implications for the welfare of the birds in production environments when encountering unfamiliar individuals.

Prediction of implantable ECG lead systems by using thorax models.

New implantable ECG devices may provide more stable and noiseless measurements compared to body surface ECG measurements. When the electrodes are moved to inside of the body the way the ECG measurement is done is changing. Modeling can be an effective way to study effects of implantation to the capacity of electrodes to measure ECG compared to surface measurements. This work introduces a project where effects of electrode implantation to the magnitude and direction of lead sensitivity to detect cardiac source, lead field, was studied with a model of the thorax as a volume conductor. The study was based on 3D finite difference method (FDM) featuring visible human man. The results of the study indicate that the effect of electrode implantation under the skin (5-15 mm) to the way they measure ECG is rather small. Magnitude change is dependent of the studied lead and the change of the sensitivity to heart's equivalent sources in direction of lead field is minor.

Expression of neurotrophins BDNF and NT-3, and their receptors in rat brain after administration of antipsychotic and psychotrophic agents.

We have investigated the potential role of neurotrophic factors in antipsychotic drug action by examining the effects of antipsychotic and psychotropic treatments on the mRNA expression of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and their receptors, trkB and trkC, respectively, in rat brain. Neither acute nor chronic clozapine treatment significantly affected the expression of these mRNAs in any brain area investigated, except for a decrease in trkB expression in the granule cells of the olfactory bulb. We then examined the effects of the psychotropic agent MK-801. MK-801 (5 mg/kg; 4 h) significantly increased BDNF mRNA in the entorhinal cortex, but did not influence NT-3, trkB, or trkC expression in any brain area except for the olfactory bulb. The induction of BDNF mRNA by MK-801 was attenuated by pre-treatment (1 h prior to MK-801 administration) with the antipsychotics, clozapine (25 mg/kg) and haloperidol (2 mg/kg), but not with the antidepressant desipramine (15 mg/kg). Finally, we confirmed that the effects of MK-801 on BDNF mRNA were reflected in the respective changes in BDNF protein levels: MK-801 significantly increased anti-BDNF reactivity in the entorhinal cortex (126 +/- 7% of control) while concomitantly decreasing in the hippocampus (71 +/- 2% of control). These data do not support the hypothesis that neurotrophins play an important role in antipsychotic drug action, but rather suggest that induction of BDNF in the entorhinal cortex may play a significant role in the psychotropic action of MK-801.

Excitatory actions of NMDA receptor antagonists in rat entorhinal cortex and cultured entorhinal cortical neurons.

We have characterized excitatory effects of non-competitive NMDA receptor antagonists MK-801, PCP, and ketamine in the rat entorhinal cortex and in cultured primary entorhinal cortical neurons using expression of immediate early gene c-fos as an indicator. NMDA receptor antagonists produced a strong and dose-dependent increase in c-fos mRNA and protein expression confined to neurons in the layer III of the caudal entorhinal cortex. Induction of c-fos mRNA is delayed and it is inhibited by antipsychotic drugs. Cultured entorhinal neurons are killed by high doses of MK-801 and PCP but c-fos expression is not induced in these neurons indicating that this in vitro model does not fully replicate the in vivo effects of PCP-like drugs in the entorhinal cortex. Excitatory effects of the NMDA receptor antagonists may be connected with the psychotropic side effects of these drugs and might become a useful model system to investigate neurobiology of psychosis.

Glomerulonephritis induced by high doses of ovalbumin. Studies by electron microscopy, immunofluorescence and immuno-electron microscopy.

Experimental glomerulonephritis was produced in 16 rabbits by intravenous injections of ovalbumin in high doses (0.1 g/day during the first week, 0.2 g x 6/day during the second). The animals were killed on day 14. At that time all animals had 2--4+ proteinuria and a serum C3 level reduced to about 50% of the control level; 11 animals had a significantly raised blood urea level. In all rabbits the antigen had induced severe proliferative glomerulonephritis. Electron microscopy showed that many of the cells accounting for the hypercellularity were monocytes. Surprisingly, electron dense deposits were few and small, mainly on the subendothelial and subepithelial aspects of the glomerular basement membrane. In all the animals ultrastructural immunoperoxidase technique revealed deposits containing ovalbumin, rabbit IgG and C3. With immunofluorescence sparse deposits were occasionally seen. It is concluded that a severe experimental glomerulonephritis can be produced in a state of antigen excess, with the deposition of immune complexes being minimal. Immuno-electron microscopy is essential, however, in detecting even the smallest animals of deposited immune reactants.

Aspiration biopsy of the kidney with a new fine needle: a way to obtain glomeruli for morphological study.

An improved fine needle is described for aspiration of kidney glomeruli. The needle, with a sharp inner edge 0.43 mm in diameter, is less traumatic than ordinary percutaneous kidney biopsy needles. Electron microscopy of specimens aspirated from kidneys of normal rabbits showed well-preserved glomeruli. Twenty-two of twenty-six specimens obtained from human kidneys by fine-needle aspiration contained glomeruli. Electron microscopic study of specimens aspirated from 12 patients showed that the needle provides adequate tissue for the diagnosis of diffuse glomerular diseases. The use of the fine needle widens the scope for studying the relation between glomerular fine structure and renal symptoms in many conditions in which conventional methods would not be justified.

Studies on the chemical composition and biological properties of transfer factor.

Dialyzable transfer factor (dTF) was fractionated on Sephadex G-10 and G-25 fine columns, and biological activity was found in 3 fractions. One of these, designated VIa, and having a tendency to adsorb to the Sephadex G-10 gel, was shown to have a therapeutic effect on certain immunological diseases. Analysis of this fraction on thin-layer and gas chromatography and with infrared and mass spectroscopy indicated that about half of this fraction was composed of uracil; additional unidentified heterocyclic and aromatic substances were present in this fraction. Adjacent fraction V contained tyrosine and a small polyribonucleotide, and fraction VII hypoxanthine and additional unidentified components. Our results suggest that the therapeutic activity of dTF is not mediated through an immunologically specific informational molecule, but is rather based on non-specific stimulation of the expression of the immune response.