Membrane fractions of trypanosomes mimic the immunosuppressive and mitogenic effects of living parasites on the host

African trypanosomiasis in mice leads to profound changes in lymphoid tissues. In an attempt to define the nature of the trypanosome stimulus, we have studied the effect of radio-attenuated trypanosomes and their subcellular fractions in vivo. We find that relatively low doses of irradiated Trypanosoma brucei S42 injected into (CBA/H x C57B1/6)F1 mice mimicked the previously reported effects of infective parasites. 2 x 10(7) irradiated trypanosomes caused a greater than two-fold increase in spleen weight accompanied by a roughly 10-fold increase in background plaque forming cells (PFC) to sheep red blood cells (SRBC). The primary response to SRBC was significantly enhanced when priming was carried out on the day of trypanosome injection, but significantly suppressed when carried out 3 days later. Disruption of trypanosomes by freeze-thawing did not destroy their mitogenic or immunosuppressive activities. A membrane fraction collected by high speed centrifugation (150 000 x g) after removal of larger organelles at 12 000 x g retained both mitogenic and suppressive activities. The high speed supernatant lost the ability to enhance background PFC, but still caused partial immunosuppression with a much lower potency than the membrane pellet. Whether immunosuppression and enhanced PFC levels relate to the same parasite product is not clear as yet, but both effects can be ascribed to a membrane fraction of the parasite.     

Valve movement response of the mussel Dreissena polymorpha -- the influence of pH and turbidity on the acute toxicity of pentachlorophenol under laboratory and field conditions

The Dreissena-Monitor is a biological early warning system for the continuous monitoring of water quality, based on the computer assessment of valve movements in two groups of 42 zebra mussels (Dreissena polymorpha). In the laboratory, two series of toxicity tests were conducted with PCP. (1) At neutral pH conditions only the concentration of PCP was altered. The dose--response relationship revealed 15 g l–1 PCP for the number of valve movements and 20 g l–1 PCP for the percentage of open mussels. (2) At 50 g l–1 PCP the pH value was altered from 6.5 to 8.4, demonstrating an inverse relationship between the toxicity of PCP and the pH. The detection limits evaluated from a series of toxicity tests under the field conditions of the River Rhine at Koblenz were nearly ten times higher than those from the laboratory. During a second series of toxicity tests under the field conditions of the River Rhine at Bad Honnef, the toxicity of PCP seemed to be reduced in relation to the increasing turbidity. The differences between the results obtained under laboratory and field conditions are discussed with respect to the influence of the pH and turbidity at the toxicity of PCP on D. polymorpha     

Influence of external cardiac pacing on cerebral oxygenation measured by near‐infrared spectroscopy in children after cardiac surgery

Background: The brain of children in the early period after repair of congenital heart defects with cardiopulmonary bypass (CPB) may be more vulnerable to hemodynamic changes because of impaired cerebral autoregulation. During postoperative testing of the external temporary safety pacer, we performed desynchronizing ventricular pacing (VVI) while monitoring cerebral oxygenation using near‐infrared spectroscopy (NIRS). Methods: We prospectively investigated 11 children (6 girls, 5 boys). Mean age was 6.1 months (±3.8 months) and mean weight: 5.3 kg (±1.5 kg). We performed measurements at four study steps: baseline I, VVI pacing, baseline II and atrial pacing (AOO) to exclude effects of higher heart rate. We continuously measured the effects on hemodynamic and respiratory parameters as well as on cerebral tissue oxygenation index (TOI). Hemoglobin difference (HbD) was calculated as a parameter for cerebral blood flow (CBF). Results: Ventricular pacing leads to a significant decrease in arterial blood pressure and central venous saturation accompanied by an immediate and significant decrease in TOI (63.3% ± 7.6% to 61.5% ± 8.4% [P < 0.05]) and HbD (0.51 ± 1.8 μmol·l⁻¹ to −2.9 ± 4.7 μmol·l⁻¹ [P < 0.05]). Conclusion: Cardiac desynchronization after CPB seems to reduce CBF and cerebral oxygenation in children.     

A Split-Face Comparison Study of Pulsed 532-nm KTP Laser and 595-nm Pulsed Dye Laser in the Treatment of Facial Telangiectasias and Diffuse Telangiectatic Facial Erythema

BACKGROUND AND OBJECTIVES: Pulsed 595 nm and 532 nm lasers can effectively diminish or eliminate facial telangiectasia. We performed a split-face, single-blind, controlled, comparison study in an effort to determine their individual and comparative efficacy. STUDY DESIGN/MATERIALS AND METHODS: Fifteen patients were treated using a 595-nm PDL on one side of the face and a pulsed 532-nm potassium-titanyl-phosphate (KTP) laser on the other. Each subject was evaluated at 3 weeks after three treatments. RESULTS: Both devices improved telangiectasia. The 532-nm device, however, was at least as effective or more effective than the 595-nm laser in all subjects. On average, the KTP laser achieved 62% clearing after the first treatment and 85% clearing 3 weeks after the third treatment, compared to 49% and 75% for the PDL, respectively. Seventy-nine percent of KTP laser-treated patients continued to have swelling for greater than 1 day versus 71% of PDL-treated patients. Of those patients who noted persistent erythema for at least 1 day after treatment, 58% noted more erythema on the KTP laser-treated side compared to 8% on the PDL-treated side. CONCLUSIONS: Both the 595-nm and the 532-nm pulsed lasers are highly effective in the treatment of facial telangiectasia and redness. The 532-nm KTP laser appears to be more effective but causes more swelling and erythema.     

Scabies with Clinical Features and Positive Darier Sign Mimicking Mastocytosis

Abstract:  Scabies is a common human parasitic infection in infants and children. But diagnosis pitfalls are frequent in infants, in whom the clinical presentation is usually atypical and different from adults. We report a misleading case of a 5-month-old child, who presented with pruritic brown–red macules of the trunk showing a positive Darier's sign, suggestive of an urticaria pigmentosa.     

Evidence of validity in a new method for measurement of dexterity in children and adolescents

Aim Many everyday activities involve manipulation of objects with the fingertips. Impaired performance in manipulative tasks is common in neurodevelopmental disorders. Thus accurate assessment of an individual’s ability to coordinate fingertip forces is important for planning treatment. We evaluated a recently developed assessment tool (the Strength–Dexterity Test), which is based on manipulation of unstable objects, in a paediatric population. Method A Rasch model was used to examine the validity and reliability of the Strength–Dexterity Test in a sample of 56 typically developing children and adolescents (30 males, 26 females; age range 4y 10mo–17y 3mo; mean age 9y 8mo, SD 3y 8mo). In addition, we examined how performance on this test relates to widely used tests for assessment of gross manual dexterity (assessed with the Box and Blocks Test) and finger strength measured with a pinch meter. Results The constructs measured with the 78‐item Strength–Dexterity Test include dexterity and strength, and form a unique unidimensional latent trait, named fingertip force coordination, that improves with age. The test has internal scale validity when applied to a typical paediatric population. Positive correlations (significant at p<0.001) were found among all three tests. Interpretation We provide preliminary evidence of construct validity in the Strength–Dexterity Test. Our findings suggest that this test has the potential to be developed into a promising tool for assessing dexterity in children.     

Circadian variation in the circumstances of delivery in a population at low obstetric risk

While circadian variations in birth and perinatal mortalityrates have previously been described in the literature, thereasons behind these observed rhythms remain unclear. The principalhypothetical causes include variations in obstetric practicesand an association between the time of birth and biologicalparameters. In order to explore this issue we analysed the distributionpatterns for time and day of birth, as well as circadian variationsin maternal characteristics, obstetric practices and neonatalrisk in a population at low obstetric risk. The study populationincluded 685 low-risk pregnant women consecutively admittedat an early stage of labour to six maternity units. The resultsshowed hourly variations in the birth rate and circadian variationsin obstetric practices that might explain the hourly patternobserved for the birth rate. By contrast, the frequency of apositive neonatal risk indicator was uniform across all timecategories in this population at low obstetric risk.     

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY IMPROVES DIAGNOSTIC EFFICIENCY OF CARBOHYDRATE-DEFICIENT TRANSFERRIN

Carbohydrate-deficient transferrin (CDT) is considered a usefulbiochemical marker of regular high alcohol intake. CDT was measuredin the sera of 51 alcohol abusers, 20 patients with nonalcoholicliver disease and 30 healthy controls with an alcohol intakeof <30g/day. The mean CDT levels of these three groups respectivelywere determined with high-performance liquid chromatography(HPLC; 4.6 ± 5.2%; 0.7 ± 0.2%; 0.7 ± 0.2%)and with a radioimmunoassay after microcolumn anion-exchangechromatography (MAEC/RIA; 34.2 ± 26.9 U/1; 16.9 ±3.8 U/1; 18.0 ± 5.7 U/1). CDT levels in patients withsevere alcohol abuse (161.6 ± 96.4g/day) were significantlyhigher than in the two other groups under investigation (P <0.0001). In heavily drinking subjects, the mean daily alcoholintake correlated with aspartate aminotransferase levels (ASAT)but not with the CDT levels determined either with HPLC or MAEC/RIA.With both methods, the CDT levels were slightly higher in patientswith an ASAT concentration >30 U/1, which may indicate anadvanced liver damage (P < 0.05). Analysis of receiver-operatingcharacteristic (ROC) plots demonstrated that the diagnosticaccuracy of the HPLC method, which determines the relative amountof CDT, was significantly higher than the established MAEC/RIAmethod, which measures the absolute amount of CDT (area underthe ROC curve: 0.95 ± 0.02 vs 0.73 ± 0.05; P <0.0001). At a specificity of >95%, the sensitivity of CDTdetermined with HPLC and MAEC/RIA was 80 and 47%, respectively.In addition, HPLC may be a useful and reliable method for thedetermination of this important biochemical marker, since theHPLC chromatogram is a visible document of the successful isotransferrinseparation and measurement.     

CARBOHYDRATE-DEFICIENT TRANSFERRIN AS A SCREENING MARKER FOR DRINKING IN A GENERAL HOSPITAL POPULATION

We investigated the usefulness of the laboratory marker of alcoholconsumption carbohydrate-deficient transferrin (CDT) in 101consecutively admitted patients in a surgical and internal medicalward of a hospital in a rural wine-growing area. Four majoraspects were considered: the influence of liver disease, themethod of expression of CDT values (relative % vs absolute units/1),level and pattern of alcohol consumption and comparison with