Application of a novel reference material in an international round robin test on material emissions testing.

Emission testing of products is currently a rapidly increasing field of measurement activity. Labeling procedures for construction products are based on such emission test chamber measurements, and hence, measurement performance should be verified. One possible route is to conduct testing of one material in different laboratories within a round robin test (RRT), ideally using homogeneous reference materials, which can be used within interlaboratory studies or as part of the quality management system to ensure comparable results. The applicability of a lacquer system with nine added VOCs (hexanal, styrene, n-decane, limonene, 2-ethyl-1-hexanol, N-methyl-α-pyrrolidone, 2-ethylhexyl acrylate, dimethyl phthalate, and n-hexadecane) was evaluated in an international RRT with 55 participating laboratories. An intralaboratory quality check confirmed the homogeneity and reproducibility of the lacquer material for most of the compounds (RSD 5%-6%), which was confirmed in the RRT. However, emissions varied for the polar compound N-methyl-α-pyrrolidone and the higher boiling compounds 1,2-dimethyl phthalate, and n-hexadecane which could be traced back to analytical issues. In the RRT, the interlaboratory relative standard deviations (RSDs) ranged from 30% to 65% for all participants but for reference laboratories the range was between 20% and 45%.

Electro-optical tunable waveguide Bragg gratings in lithium niobate induced by femtosecond laser writing.

We report the fabrication of femtosecond laser-induced, first-order waveguide Bragg gratings in lithium niobate in the low repetition rate regime. Type-II waveguides are written into an x-cut lithium niobate wafer and structured periodically to achieve narrowband reflections at wavelengths around 1550 nm. Additionally, electrodes are employed to allow for electro-optic tuning of the spectral response. We demonstrate wavelength control of the central reflection peak by applying a static external electric field. A maximum shift of the reflection peak of Δλ = 625 pm is observed.

[Considering and tackling tobacco smoking in the context of adolescent development]. / Tabak-Konsum im Kontext adoleszenter Entwicklung - was wir dagegen tun können und sollen.

The prevalence of smoking among young people is still on a high level. Many adolescents are incessantly attracted by advertising and other messages promising a fashionable, young and independent lifestyle with cigarettes as imperative symbols. Those adolescents suffering from cognitive, mental or social problems or being genetically more vulnerable have the greatest risk to misuse nicotine and to become addicted for many years. Unfortunately, being diagnosed with asthma or diabetes does not deter adolescents from smoking, thus increasing the burden of their chronic disease. Of similar concern is the considerable number of smoking young people at the reproductive age. In the last few years, only modest progress has been observed in the development of programmes, which are suited to diminish the rate of young smokers. There is a lack of effective strategies that could help them to get motivated and to stop smoking. Primary care physicians are in an unique position to contribute to adolescent smoking cessation. This article provides information to physicians on how to best accomplish this task. In order to reach sustainable changes in adolescent smoking behaviour, rigorous political steps are necessary which target on diminishing the social acceptance and attractiveness of smoking in general and on the reduction of the number of adult smokers, rather than exclusively focussing on adolescent smoking. This policy has to be supplemented with comprehensive steps to improve education and future life perspectives of adolescents.

An improved fluorochrome microassay for the detection of living and non-living intracellular bacteria in human neutrophils.

Acridine orange fluorescence may be used to distinguish living from non-living intracellular bacteria in individual glass-adherent neutrophil granulocytes (PMN). An improvement of the original assay (Smith and Rommel, 1977; Pantazis and Kniker, 1979) is described which allows differentiation between ingested and cell-adherent bacteria. It is shown that this differentiation is impossible with the original method using wet-mounted preparations. With the improved method, however, using dry-mounted preparations, cell-adherent as well as extracellular bacteria lose their fluorescence. Moreover, the fluorescence of cell nuclei and granula is reduced to a minimum. Phagocytosis kinetics and selective inhibition of the myeloperoxidase of PMN show that living intracellular bacteria fluoresce green and non-living bacteria red in such dry-mounted preparations. The preparations can be stored and interpreted for at least 2 months. Application of this method requires 0.1 ml blood or cell-rich body fluid per preparation and is fast and inexpensive.

Microbial flora on the hands of health care personnel: differences in composition and antibacterial resistance.

The composition and antibiotic sensitivity pattern of bacteria recovered from the hands of nurses and physicians in two service units of a major teaching hospital were compared with those found in a control population. Significant differences in the composition of bacteria were found in dermatology and oncology unit personnel. Staphylococcus aureus was recovered from 31% of dermatology nurses and 37% of dermatology physicians compared with 20% of oncology nurses, 15% of oncology physicians, and 17% of controls. Oncology personnel had a significantly higher carriage of gram-negative bacteria, yeasts, and multiple antibiotic-resistant, aerobic coryneforms (group JK bacteria). Both dermatology and oncology nursing personnel were colonized by organisms resistant to multiple antibiotics. Methicillin resistance was found in 26% and 66% of the staphylococci recovered from dermatology and oncology nurses respectively. Flora from physicians on the two units had sensitivity patterns similar to controls.

Additive effects of psychostimulants, parent training, and self-control therapy with ADHD children.

Utilizing a double-blind, placebo design, the effects of a high (0.8 mg/kg) and a low (0.4 mg/kg) dose of methylphenidate alone and in combination with behavioral parent training plus child self-control instruction were evaluated with 96 attention deficit hyperactivity disorder children. No evidence of the superiority of the combined conditions relative to medication alone was found. Some limited support was found for the hypothesis that the effects of a high dose of psychostimulant medication could be achieved by combining the low dose with a behavioral intervention. The importance of the latter finding is highlighted by the fact that both the benefits and untoward effects of the psychostimulants appear to increase with the dose.

The effects of a multimodal intervention with attention-deficit hyperactivity disorder children: a 9-month follow-up.

Using a double-blind, placebo design, we evaluated 96 attention-deficit hyperactivity disordered children for the effects of methylphenidate alone and in combination with behavioral parent training plus child self-control instruction. Seventy one of the children completed the treatment protocol. As reported previously, main effects were found for medication at posttest; however, there was no evidence of additive effects. Nine months after the termination of the behavioral interventions and the withdrawal of the stimulant medication, we found limited support for the hypothesis that the combined conditions would produce greater maintenance of treatment gains than would medication alone.

In vitro effects of fenretinide on cell-matrix interactions.

BACKGROUND: Understanding the molecular basis of the metastatic spread of cancer and the underlying mechanisms is crucial for the development and appropriate clinical use of novel therapeutic agents directed at prevention of metastasis. Retinoids have been reported to inhibit cell proliferation, modulate cell differentiation, enhance apoptosis and to prevent the conversion of in situ cancer to locally invasive malignancy by suppressing the invasive process as well as by inhibiting angiogenesis. Fenretinide (4-HPR), a synthetic derivative of retinoic acid, is less toxic than natural retinoids and is active in the prevention and treatment of a variety of tumours in animal models. Its efficacy in cancer chemoprevention and therapy has been investigated in clinical trials. MATERIALS AND METHODS: In order to evaluate the effects of 4-HPR on the late stages of tumour progression, chemically transformed BALB/c 3T3 cells, showing a fully malignant phenotype, were exposed to 4-HPR (0.25-10 microM; 72 hours pre-treatment) and then analysed for in vitro invasive ability. The possible mechanisms of action responsible for the anti-invasive activity of 4-HPR were investigated, analysing cellular adhesion, motility, and proteolytic capability. RESULTS: Data showed that 4-HPR significantly inhibited the invasive phenotype of chemically transformed cells; the reduction in Matrigel invasion was dose-dependent and seemed not to be related to cytotoxic effects or reduction in cell proliferation rates induced by 4-HPR assayed doses. The 4-HPR-induced decrease in chemotactic motility of transformed cells correlated well with the invasion inhibition. 4-HPR, at active concentrations, differently affected cell adhesion to the extracellular matrix, depending on the coating substrate used (laminin, collagen IV, fibronectin and vitronectin). 4-HPR treatment significantly enhanced cell adhesion to laminin, while reducing cell-vitronectin attachment. It did not modify the attachment of the cells to fibronectin and collagen IV. Zymographic analysis failed to demonstrate 4-HPR involvement in the modulation of the activity and expression of gelatine degrading enzymes. CONCLUSION: These data suggest that 4-HPR inhibits tumour cell invasion through a basement-like matrix, by suppressing chemotactic motility and by altering cell-matrix interactions.

Effects of the protease inhibitor antipain on cell malignant transformation.

BACKGROUND: Several natural products have been found to exhibit a chemopreventive activity both in in vivo and in vitro experimental systems. Among them, protease inhibitors seem to play a key role in the regulation of growth and phenotypic expression of transformed cells as well as in the regulation of the late events of carcinogenesis. We evaluated the effect of antipain (AP), a natural protease inhibitor, on chemically induced BALB/c 3T3 cell transformation, on invasion and chemotactic motility of transformed cells and on their gelatinase expression. METHODS: BALB/c 3T3 cells were plated and exposed to 2.5 micrograms/ml 3-MCA or 50 micrograms/ml, 1,2-DBE. The effect of a non-cytotoxic dosage of AP (10 microM) was studied by: a) pretreating cells with AP for 48 hours before the carcinogen exposure; b) adding AP simultaneously to the carcinogen treatment; c) chronic addition of AP at each medium change throughout the experimental duration. The effectiveness of the treatment was analysed as the ability to reduce or inhibit the occurrence of transformed foci. Modulation of the invasive phenotype by anti-transforming dosages of AP was evaluated by in vitro Matrigel invasion assay. Gelatin zymography was performed in order to assess AP regulation of proteolytic enzymes, such as metalloproteases, involved in invasion and metastasis. RESULTS: AP treatment can reduce the transformation rate both in 3-MCA- and 1,2-DBE-initiated cells. Its effectiveness depends on the administration schedule, and chronic addition seems to be the most effective treatment. The concentration of AP, which is effective in the antitransformation assay, is not able to significantly affect the migration and invasion of chemically transformed cells or their gelatinase activity. CONCLUSIONS: AP can suppress chemically induced BALB/c 3T3 cell transformation through mechanisms which do not involve modulation of the invasive phenotype.

[On the physiology of the growth of nail plate (author's transl)]. / Ein Beitrag zur Physiologie des Nagelwachstums.

By following up histologically a localized storage of melanin in certain layers of the nail plate the differing theories on the cellular kinetics of the growth of human nail plate are checked up. Thus it turns out that the hitherto existing and even contradicting conceptions are not helpful to interpret uniquely the morphological phenomena of the concrete case. A plausible modification is presented.

AI in medicine on its way from knowledge-intensive to data-intensive systems.

The last 20 years of research and development in the field of artificial intelligence in medicine (AIM) show a path from knowledge-intensive systems, which try to capture the essential knowledge of experts in a knowledge-based system, to data-intensive systems available today. Nowadays enormous amounts of information is accessible electronically. Large datasets are collected continuously monitoring physiological parameters of patients. Knowledge-based systems are needed to make use of all these data available and to help us to cope with the information explosion. In addition, temporal data analysis and intelligent information visualization can help us to get a summarized view of the change over time of clinical parameters. Integrating AIM modules into the daily-routine software environment of our care providers gives us a great chance for maintaining and improving quality of care.

Automatic knowledge base refinement: learning from examples and deep knowledge in rheumatology.

MESICAR is a second generation expert system which contains very general descriptions of rheumatological disorders in the primary medical care field. With the help of a detailed hierarchical description of the human anatomy the system is able to support diagnostic decisions. The paper describes how machine learning techniques are used to automatically construct more specific disease descriptions for common, frequently occurring cases. The system MESICAR-LEARN implements a learning method which integrates analytical and empirical learning techniques. Cases diagnosed by MESICAR form the training examples, and MESICAR's knowledge base is used as domain theory. The learned concepts are integrated into a hierarchy of disease descriptions. They support efficient and fast reasoning on common cases in addition to the general diagnostic support afforded by MESICAR's deep knowledge.

Utilizing temporal data abstraction for data validation and therapy planning for artificially ventilated newborn infants.

Medical diagnosis and therapy planning at modern intensive care units (ICUs) have been refined by the technical improvement of their equipment. However, the bulk of continuous data arising from complex monitoring systems in combination with discontinuously assessed numerical and qualitative data creates a rising information management problem at neonatal ICUs (NICUs). We developed methods for data validation and therapy planning which incorporate knowledge about point and interval data, as well as expected qualitative trend descriptions to arrive at unified qualitative descriptions of parameters (temporal data abstraction). Our methods are based on schemata for data-point transformation and curve fitting which express the dynamics of and the reactions to different degrees of parameters' abnormalities as well as on smoothing and adjustment mechanisms to keep the qualitative descriptions stable. We show their applicability in detecting anomalous system behavior early, in recommending therapeutic actions, and in assessing the effectiveness of these actions within a certain period. We implemented our methods in VIE-VENT, an open-loop knowledge-based monitoring and therapy planning system for artificially ventilated newborn infants. The applicability and usefulness of our approach are illustrated by examples of VIE-VENT. Finally, we present our first experiences with using VIE-VENT in a real clinical setting.

Conjugated linoleic acid supplementation in humans: effects on fatty acid and glycerol kinetics.

Recent studies with mouse adipocytes have shown that dietary conjugated linoleic acid (CLA) may reduce body fat by increasing lipolysis. The present study examined the effect of CLA supplementation on fatty acid and glycerol kinetics in six healthy, adult women who were participating in a controlled metabolic ward study. These women were fed six CLA capsules per day (3.9 g/d) for 64 d following a baseline period of 30 d. The subjects were confined to a metabolic suite for the entire 94-d study, where diet and activity were controlled and held constant. The rate of appearance (Ra) of glycerol, which indicates lipolytic rates, was similar at baseline and after 4 wk of CLA supplementation at rest (1.87 +/- 0.21 and 2.00 +/- 0.39 micromol/kg/min, respectively) and during exercise (7.12 +/- 0.74 and 6.40 +/- 0.99 micromol/kg/min, respectively). Likewise, the Ra of free fatty acids (FFA) was not significantly different after 4 wk of dietary CLA at rest (2.72 +/- 0.06 and 2.74 +/- 0.12 micromol/kg/min, respectively) or during exercise (6.99 +/- 0.40 and 5.88 +/- 0.29 micromol/kg/min, respectively). CLA supplementation also had no effect on the percentage of FFA released from lipolysis that were re-esterified. The apparent rate of FFA re-esterification was 65.2 +/- 4.2% at rest and 32.1 +/- 3.44% during exercise. Four weeks of CLA supplementation had no significant effect on fatty acid or glycerol metabolism in healthy, weight-stable, adult women.

Conjugated linoleic acid supplementation in humans: effects on circulating leptin concentrations and appetite.

Conjugated linoleic acid (CLA) has been demonstrated to reduce body fat in animals. However, the mechanism by which this reduction occurs is unknown. Leptin may mediate the effect of CLA to decrease body fat. We assessed the effects of 64 d of CLA supplementation (3 g/d) on circulating leptin, insulin, glucose, and lactate concentrations in healthy women. Appetite was assessed as a physiological correlate of changes in circulating leptin levels. Analysis of plasma leptin concentrations adjusted for adiposity by using fat mass as a covariate showed that CLA supplementation significantly decreased circulating leptin concentrations in the absence of any changes of fat mass. Mean leptin levels decreased over the first 7 wk and then returned to baseline levels over the last 2 wk of the study in the CLA-treated group. Appetite parameters measured at around the time when the greatest decreases in leptin levels were observed showed no significant differences between supplementation and baseline determinations in the CLA-supplemented group or between the CLA and placebo-supplemented groups. There was a nonsignificant trend for mean insulin levels to increase toward the end of the supplementation period in CLA-treated subjects. CLA did not affect plasma glucose and lactate over the treatment period. Thus, 64 d of CLA supplementation in women produced a transient decrease in leptin levels but did not alter appetite. CLA did not affect these parameters in a manner that promoted decreases of adiposity.

Sex differences in school-aged children with pervasive attention deficit hyperactivity disorder.

This study investigated 54 children (37 boys and 17 girls) with cross-situational attention deficit hyperactivity disorder (ADHD) to determine whether there are sex differences in the expression of either the primary or secondary symptomatology of ADHD. Results indicated that the male and female ADHD groups were strikingly similar on all measures of primary (impulsivity, inattention, and overactivity) and secondary (learning problems, externalizing symptoms, internalizing symptoms, peer relationship difficulties, and self-perceptions) symptomatology included in this study. The lack of significant sex differences conflicts with prior reports in the literature, and these conflicting results are discussed in terms of differences in inclusion criteria. Implications for understanding the long-term outcome of ADHD in girls are also discussed.

Support for fast comprehension of ICU data: visualization using metaphor graphics.

OBJECTIVES: The time-oriented analysis of electronic patient records on (neonatal) intensive care units is a tedious and time-consuming task. Graphic data visualization should make it easier for physicians to assess the overall situation of a patient and to recognize essential changes over time. METHODS: Metaphor graphics are used to sketch the most relevant parameters for characterizing a patient's situation. By repetition of the graphic object in 24 frames the situation of the ICU patient is presented in one display, usually summarizing the last 24 h. RESULTS: VIE-VISU is a data visualization system which uses multiples to present the change in the patient's status over time in graphic form. Each multiple is a highly structured metaphor graphic object. Each object visualizes important ICU parameters from circulation, ventilation, and fluid balance. CONCLUSION: The design using multiples promotes a focus on stability and change. A stable patient is recognizable at first sight, continuous improvement or worsening condition are easy to analyze, drastic changes in the patient's situation get the viewers attention immediately.

Serum laminin P1 levels do not reflect critically elevated portal pressure in patients with liver cirrhosis.

BACKGROUND/AIMS: Laminin P1 serum levels run parallel to the accumulation of hepatic extracellular matrix in patients with liver cirrhosis. Recent studies reported a correlation between laminin P1 and portal pressure, leading to the proposal that laminin P1 may be used to identify patients with critically elevated portal pressure in liver cirrhosis. So far, most of the data has been obtained from patients with alcoholic liver disease. METHODOLOGY: We studied the relationship between laminin P1 serum levels and portal hypertension in 34 patients with liver cirrhosis, mostly of non-alcoholic etiology. Using hepatic venous catheterisation the hepatic venous pressure gradient (HVPG), an estimate of portal hypertension, was measured. Laminin P1 was compared to the HVPG and the size of esophageal varices. RESULTS: Serum laminin P1 was elevated in all samples. However, laminin P1 did not significantly correlate with either portal hypertension or the size of esophageal varices. Furthermore, laminin P1 measurement did not identify patients with critically elevated portal pressure using a HVPG of either 12 mmHg or 16 mmHg as cut-off points. CONCLUSION: The use of laminin P1 serum levels to diagnose critically elevated portal pressure in liver cirrhosis cannot be supported for etiologies other than alcoholic liver disease.

The reliability and validity of the maternal social support index.

The Maternal Social Support Index (MSSI) is a 21-item questionnaire designed to quickly assess qualitative and quantitative aspects of a mother's social support. Previous studies have found an association between scores on the MSSI and home stimulation of preschool children, child maltreatment, and low birthweight. This report examines the test-retest reliability, internal consistency and concurrent and predictive validity of the MSSI in three samples of mothers (N = 488) from a prenatal clinic, pediatric clinic, and psychology clinic. The MSSI was found to have a test-retest correlation of .72 (P less than 0.001) over six to eight weeks. Coefficient alphas ranged from .60 to .63 across the three samples, denoting moderate internal consistency. In the psychology clinic sample, the MSSI was found to be positively correlated with the Dyadic Adjustment Scale (r = .393, P less than 0.001) and inversely correlated with the Center for Epidemiologic Studies Depression Scale (r = .296, P less than 0.001). The MSSI is a brief, reliable instrument with acceptable internal consistency and concurrent and predictive validity. It may be employed in the primary care arenas of clinical research and patient care to provide an organized assessment of maternal social support.

Factors associated with patients' participation in rehabilitation services: a comparative injury analysis 12 months post-discharge.

PURPOSE: To determine key characteristics or factors associated with rehabilitation participation during the first year following discharge for persons with either traumatic brain injury (TBI), spinal cord injury (SCI), intra-articular fracture (IAF), or burn injury (BURNS). METHOD: Medical records and longitudinal survey [telephone questionnaire] data were collected for persons in the four injury groups and analyzed using hierarchical logistic regression procedures for each domain of factors. RESULTS: The only significant predictors with odds ratios greater than one were those for vocational rehabilitation participation. TBI patients lacking private insurance were 2.6 times more likely to participate in vocational rehabilitation; older SCI and TBI patients are about twice as likely to participate in vocational rehabilitation; and finally those with IAF or BURNS who are married at 12 months post discharge are 11.5 and 4.4 times respectively more likely to participate in vocational rehabilitation. CONCLUSION: Those lacking valuable socio-economic resources, such as private insurance (for TBI) and social support systems provided by marriage (for BURNS and IAF patients) are much more likely to be referred to vocational rehabilitation. This is true for older SCI and TBI patients as well. Lacking such resources, patients may be viewed by referral agents as less likely to benefit from in or outpatient rehabilitation.