Age Estimation and Gender Attribution in Typically Developing Children and Children With Dysarthria

PURPOSE

The purposes of this study were (a) to investigate adult listeners' perceptions of age and gender in typically developing children and children with dysarthria and (b) to identify predictors of their estimates among auditory-perceptual parameters and an acoustic measure of vocal pitch (F0). We aimed to evaluate the influence of dysarthria on the listeners' impressions of age and gender against the background of typical developmental processes.

METHOD

In a listening experiment, adult listeners completed age and gender estimates of 144 typically developing children (3-9 years of age) and 25 children with dysarthria (5-9 years of age). The Bogenhausen Dysarthria Scales for Childhood Dysarthria (BoDyS-KiD) were applied to record speech samples and to complete auditory-perceptual judgments covering all speech subsystems. Furthermore, each child's mean F0 was determined from samples of four BoDyS-KiD sentences.

RESULTS

Age estimates for the typically developing children showed a regression to the mean, whereas children with dysarthria were systematically underestimated in their age. The estimates of all children were predicted by developmental speech features; for the children with dysarthria, specific dysarthria symptoms had an additional effect. We found a significantly higher accuracy of gender attribution in the typically developing children than in the children with dysarthria. The prediction accuracy of the listeners' gender attribution in the preadolescent children by the included speech characteristics was limited.

CONCLUSIONS

Children with dysarthria are more difficult to estimate for their age and gender than their typically developing peers. Dysarthria thus alters the auditory-perceptual impression of indexical speech features in children, which must be considered another facet of the communication disorder associated with childhood dysarthria.

Clinical Practice in Childhood Dysarthria: An Online Survey of German-Speaking Speech-Language Pathologists

PURPOSE

This survey study aimed to establish current clinical practices of German-speaking speech-language pathologists (SLPs) regarding their assessment and treatment of communication disorders in children with neurological conditions, with a particular focus on the management of childhood dysarthria.

METHOD

A 23-question cross-sectional online survey was disseminated to practicing SLPs in Germany, Austria, and Switzerland via relevant professional bodies. SLPs were invited to provide information on their current assessment and treatment practices. Demographic data including case load and clinical settings were also gathered to contextualize practices.

RESULTS

One hundred two SLPs responded to the survey, of which 68 valid responses were analyzed. German-speaking SLPs comprehensively assess and treat various aspects of overall communication, language, and swallowing functions in children with neurological conditions. Speech motor aspects did not represent a main intervention focus. In cases where the dysarthric component was targeted, specific approaches for childhood dysarthria were rarely used. Instead, SLPs reported using approaches developed for speech disorders other than dysarthria.

CONCLUSIONS

German-speaking SLPs working with children with neurological conditions use various assessment and treatment methods to support children's communication. However, dysarthria-specific approaches were not an established part of clinical practice. Results of the survey highlight the need for access to relevant developments in German and for evaluation of current curricula for speech-language pathology students and continuing education opportunities for practicing clinicians.

Speech Naturalness in the Assessment of Childhood Dysarthria

PURPOSE

This study investigated perceived speech naturalness estimated by adult listeners in typically developing children and children with dysarthria. We aimed to identify predictors of naturalness among auditory-perceptual parameters and to evaluate the concept of naturalness as a clinical marker of childhood dysarthria.

METHOD

In a listening experiment, naive adult listeners rated speech naturalness of 144 typically developing children (3-9 years old) and 28 children with neurological conditions (5-9 years old) on a visual analog scale. Speech samples were recorded using the materials of the Bogenhausen Dysarthria Scales-Childhood Dysarthria, which also provides for auditory-perceptual judgments covering all speech subsystems.

RESULTS

Children with dysarthria obtained significantly lower naturalness ratings compared to typically developing children. However, there was a substantial age effect observable in the typically developing children; that is, younger typically developing children were also perceived as somewhat unnatural. The ratings of the typically developing children were influenced by the occurrence of developmental speech features; for the children with neurological conditions, specific symptoms of dysarthria had an additional effect. In both groups, the perception of naturalness was predominantly determined by the children's articulation and intelligibility.

CONCLUSIONS

Both symptoms of childhood dysarthria and developmental speech features (e.g., regarding articulation and intelligibility) were associated to some extent with unnatural speech by the listeners. Thus, perceived speech naturalness appears less suitable as a marker of dysarthria in children than in adults.

Intelligibility, Speech Rate, and Communication Efficiency in Children With Neurological Conditions: A Longitudinal Study of Childhood Dysarthria

PURPOSE

This study aimed to describe communication-related parameters (i.e., intelligibility, speech rate, and communication efficiency) and their developmental courses in children with neurological conditions against the background of typical development. In addition, interrelations between the developmental courses of communication-related parameters and auditory-perceptual ratings related to speech subsystems were investigated.

METHOD

Fourteen children with neurological conditions (CNC) and 14 typically developing children (CTD), matched for age and gender (four girls; 5;1-8;4 [years;months] at first examination), were assessed at three points in time over an 18-month period. Speech samples were collected using the Bogenhausener Dysarthrie Skalen-Kindliche Dysarthrien (English: Bogenhausen Dysarthria Scales-Childhood Dysarthria), a German tool for the assessment of childhood dysarthria. To assess intelligibility, naïve listeners transcribed audio samples of sentence repetitions of the children. Speech rate was measured by acoustic analyses, and communication efficiency was determined by multiplying the proportion of correctly transcribed syllables with speech rate. Age normalization was performed following a recently published approach.

RESULTS

On the group level, CNC had conspicuous raw and normalized scores for the three communication-related parameters and were more variable than the CTD group regarding their developmental courses. These differences were more pronounced for intelligibility than for speech rate. A strong relationship between communication-related and speech subsystems-related auditory-perceptual characteristics was apparent only between intelligibility and articulation/resonance.

CONCLUSIONS

For the first time, age-normalized scores for communication-related parameters were reported in children with neurological disorders and put into a developmental context within the framework of a longitudinal study. Age-normalized intelligibility was more vulnerable to large developmental changes than speech rate and was best predicted by changes in articulation and resonance. Overall, this study may contribute to a more comprehensive and valid clinical assessment of childhood dysarthria and to a better understanding of its developmental dynamics.

Childhood Dysarthria: Auditory-Perceptual Profiles Against the Background of Typical Speech Motor Development

PURPOSE

The purpose of this study was to describe childhood dysarthria by means of auditory-perceptual analyses covering all speech subsystems. We aimed to identify the most seriously affected auditory-perceptual dimensions in the observed dysarthria profiles and to detect specific markers of childhood dysarthria against the backdrop of typical speech development. Moreover, the relationship between the speech disorder and other relevant aspects of multiple disability was investigated.

METHOD

Thirty-one children with neurologic conditions were assessed with Bogenhausen Dysarthria Scales for Childhood Dysarthria, a German tool for the auditory-perceptual analysis of dysarthria in children. Nine relevant speech dimensions (scales, e.g., voice quality [VOQ]) and 29 individual symptoms (features, e.g., breathy) were evaluated. Moreover, we documented motor, communicative, and cognitive-linguistic measures (i.e., Gross Motor Function Classification System [GMFCS], Communication Function Classification System [CFCS], Test for Reception of Grammar [TROG-D], and memory span). Recently published data from typically developing children were used for the purpose of age normalization.

RESULTS

Dysarthria severity was moderately correlated with GMFCS and CFCS but not with TROG-D and memory span. At the group level, respiration, articulation, and prosodic modulation were most severely affected, whereas voice function was only mildly affected or even spared in the majority of children. Four features were identified as most relevant markers of childhood dysarthria: conspicuous rhythm/stress pattern, hypernasality, strained-strangled voice, and reduced articulatory precision.

CONCLUSIONS

Childhood dysarthria is part of a complex multiple disability, but speech motor skills may still dissociate from gross-motor and cognitive-linguistic functions. Auditory-perceptual analyses incorporating age norms allow for a comprehensive description and identification of childhood dysarthria.

Intelligibility, Articulation Rate, Fluency, and Communicative Efficiency in Typically Developing Children

Purpose This article describes the developmental trajectories of four communication-related parameters (i.e., intelligibility, articulation rate, fluency, and communicative efficiency) in a cross-sectional study of typically developing children between 3 and 9 years. The four target parameters were related to auditory-perceptual parameters of speech function. Method One hundred forty-four typically developing children (ages 3;0-9;11 [years;months]; 72 girls and 72 boys) participated. Speech samples were collected using the materials of the Bogenhausen Dysarthria Scales for Childhood Dysarthria, a German assessment tool for childhood dysarthria, and analyzed following established auditory-perceptual criteria on relevant speech functions. To assess intelligibility, naïve listeners transcribed sentences repeated by the children. Articulation rate and fluency were measured by acoustic analyses; communicative efficiency was determined by multiplying the proportion of correctly transcribed syllables by speech rate. Results Intelligibility showed a steep developmental trajectory, with the majority of children obtaining a proportion of intelligible syllables close to 1.0 at the age of 5 years. Articulation rate demonstrated a flatter trajectory, with high variability still within the older children. Disfluencies, on the contrary, occurred only in the youngest children. By definition, communicative efficiency shared the characteristics of intelligibility and rate curves. A principal component analysis revealed, among other findings, strong connections between intelligibility and articulation, as well as between communicative efficiency, articulation, and rate measures. Conclusions While children speak intelligibly, in terms of the applied assessment, at a comparably young age, other communication-relevant parameters show a slower developmental progress. Knowledge on the typical development of communication-related parameters and on their complex relationships with functional speech variables is crucial for the clinical assessment of childhood dysarthria. Supplemental Material https://doi.org/10.23641/asha.14880285.

Developmental Courses in Childhood Dysarthria: Longitudinal Analyses of Auditory-Perceptual Parameters

Purpose The aim of this longitudinal study was to describe developmental courses of childhood dysarthria against the background of typical speech motor development by collecting auditory-perceptual data. Method Fourteen children (four girls, 10 boys; 5;1-8;4 [years;months] at Time 1) with neurological conditions (CNC) and 14 typically developing children (CTD) matched for age and gender were assessed at three points in time over an 18-month period. Speech samples were collected using the Bogenhausener Dysarthrie Skalen-Kindliche Dysarthrien (BoDyS-KiD; in English: Bogenhausen Dysarthria Scales-Childhood Dysarthria), a German tool for the assessment of childhood dysarthria, and analyzed by means of nine perceptual scales covering all clinically relevant speech components. Age normalization was performed according to a method published recently. Data from the matched controls were used to estimate whether the gradients of the CNC group's developmental trajectories exceeded those of typical development. Results The children with neurological conditions presented heterogeneous speech profiles with a wide range of severity. At the group level, relatively stable trajectories of the age-normalized dysarthria total score were found over the observation period. The nine perceptual scales showed more or less parallel developments. All patients except two followed the growth curve describing the developmental course of the typically developing children. Conclusions Most children took advantage of the developmental dynamics as they developed parallel to the age norm. With its comprehensive description of the developmental courses of 14 children with neurological conditions, this study may contribute to a more valid, statistically verified clinical assessment of the course of childhood dysarthria.

Dysarthria syndromes in children with cerebral palsy

AIM

To investigate whether dysarthria syndromes acquired in adulthood can also be observed in children with cerebral palsy (CP) and, if so, whether they align with children's CP subtypes.

METHOD

Twenty-six children with CP participated (mean age 7y 8mo [SD 1y 2mo], 5y 1mo-9y 10mo; 16 males and 10 females). Speech samples were elicited in a computer-based game and were analysed using the auditory perceptual criteria of the Bogenhausen Dysarthria Scales (BoDyS). For statistical classification, three comparison groups of adults with standard dysarthria syndromes (i.e. spastic, hyperkinetic, and ataxic) were used. Their BoDyS data were entered into a mixture discriminant analysis, with data from the comparison groups as the training sample and those from the children with CP as the test sample. Results were related to findings in a group of adults with CP.

RESULTS

Among the children with CP, most had spastic (n=14), while fewer had ataxic (n=9) or hyperkinetic (n=3), dysarthria. However, syndrome allocations were significantly more ambiguous than in adults with CP. For 11 children, their dysarthria syndromes did not align with their CP subtype.

INTERPRETATION

Dysarthria syndromes are less clear cut in children than in adults with CP because of a number of developmental factors.

WHAT THIS PAPER ADDS

Children with cerebral palsy (CP) show diverse patterns of dysarthric symptoms. Dysarthria syndromes do not seem to manifest fully during childhood. Dysarthria syndrome and CP subtype may not align in children with CP.

Age Norms for Auditory-Perceptual Neurophonetic Parameters: A Prerequisite for the Assessment of Childhood Dysarthria

Purpose The aim of this study was to collect auditory-perceptual data on established symptom categories of dysarthria from typically developing children between 3 and 9 years of age, for the purpose of creating age norms for dysarthria assessment. Method One hundred forty-four typically developing children (3;0-9;11 [years;months], 72 girls and 72 boys) participated. We used a computer-based game specifically designed for this study to elicit sentence repetitions and spontaneous speech samples. Speech recordings were analyzed using the auditory-perceptual criteria of the Bogenhausen Dysarthria Scales, a standardized German assessment tool for dysarthria in adults. The Bogenhausen Dysarthria Scales (scales and features) cover clinically relevant dimensions of speech and allow for an evaluation of well-established symptom categories of dysarthria. Results The typically developing children exhibited a number of speech characteristics overlapping with established symptom categories of dysarthria (e.g., breathy voice, frequent inspirations, reduced articulatory precision, decreased articulation rate). Substantial progress was observed between 3 and 9 years of age, but with different developmental trajectories across different dimensions. In several areas (e.g., respiration, voice quality), 9-year-olds still presented with salient developmental speech characteristics, while in other dimensions (e.g., prosodic modulation), features typically associated with dysarthria occurred only exceptionally, even in the 3-year-olds. Conclusions The acquisition of speech motor functions is a prolonged process not yet completed with 9 years. Various developmental influences (e.g., anatomic-physiological changes) shape children's speech specifically. Our findings are a first step toward establishing auditory-perceptual norms for dysarthria in children of kindergarten and elementary school age. Supplemental Material https://doi.org/10.23641/asha.12133380.

P2683Beneficial effects of red wine intake upon gut microbiota and parallel effects upon plasma metabolomics

Background

Evidence suggests that red wine (RW) components can influence favorably gut microbiota. However, Interactions of RW, gut microbiota and plasma metabolomics remain unclear.

Purpose

The goal of this study was to assess the effects upon gut microbiota and plasma metabolomic profile of short-term, moderate RW intake in patients (pts) with documented coronary artery disease (CAD)

Methods

Forty-two males aged 60.4±5.4 years (SD) with documented CAD by angiography underwent a randomized, crossover, controlled, interventional trial. They were assigned to either RW treatment or abstinence from any alcoholic beverage, as control. Each treatment was preceded by a 2-week washout period. During the RW intervention, subjects ingested 250 ml of RW per day/ 5 days a week/ 3 weeks. Fasting blood samples and fecal samples were collected 4 times, after washout and at the end of each 3-week intervention. Gut microbiota was analysed by 16 S rRNA gene sequences and plasma metabolomics was performed by Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectroscopy. Twenty pts chosen randomly had their global metabolic profiles examined at all visits. Diet was carefully controlled and quantified by a 3 day/week questionnaire at beginning and end of the study. Prebiotics, probiotics were not allowed during the study. Patients in need for antibiotic therapy were not included.

Results

In the RW period compared to abstinence, fecal metagenomic revealed a decrease in abundance of Collinsella, a bacterial genus correlated with atherosclerosis; an increase in Eubacterium, genus related to fiber digestion and bile acid metabolism; and a significant increase in alpha diversity (p<0.05 for all). In plasma, trimethylamine N-oxide (TMAO), fell non-significantly post RW consumption. HDL and resveratrol increased after RW consumption (p<0.05). Plasma metabolomic analysis of 20 pts revealed microbiome related changes associated with RW consumption: decreased levels of phenylalanine, benzoate, tyrosine and tryptophan; lower levels of primary bile acids (BA) cholate, taurocholate, and also secondary BA deoxycholate and lithocholate sulfate. In parallel, RW elevated androgenic steroids and decreased beta oxidation (p<0.05 for all). Simultaneously total energy, proteins, carbohydrates and fat components of the diet did not change significantly.

Conclusions

Moderate RW ingestion augmented microbiota diversity, increased the proportion of putative anti-atherosclerotic bacteria and influenced plasma metabolomics. RW influenced energy metabolism through gut microbiota related plasma changes in amino acids, nucleotide profile, bile acids, androgenic steroids and beta-oxidation. These findings furnish some novel insight into mechanisms whereby RW may mitigate atherosclerosis.

Acknowledgement/Funding

FAPESP (Fundacao de Amparo à Pesquisa do Estado de Sao Paulo), IBRAVIN (Instituto Brasileiro do Vinho), Banco Bradesco SA

Vermeintlich venöse Beschwerden

In der phlebologischen Praxis sind vermeintlich venöse Symptome wie schweres Bein, Schwellungs-, Müdigkeitsund Spannungsgefühl ohne erkennbare organische Ursache (Schweres-Bein-Syndrom) häufig. Oftmals findet sich bei den Patienten eine psychosomatische Auffälligkeit und ihre Lebensqualität ist reduziert. Die Diskrepanz zwischen Symptomen und Befunden führt nur selten zu einer geeigneten Therapie.

Diese Übersichtsarbeit versucht, die Problematik von vermeintlich venösen Beschwerden aufzuzeigen und mittels einer Pilotstudie die tatsächliche Möglichkeit der Lebensqualitätsmessung bei Personen mit Schweres-Bein-Syndrom darzustellen.

Rezidivhäufigkeit durch Neoangiogenese nach modifizierter Krossektomie

Ziel: Überprüfung, ob durch eine bestimmte operative Technik die Rate der Krossenrezidive signifikant gesenkt werden kann. Methode: In eine prospektiv-randomisierte, farbduplex-kontrollierte Studie wurden 1389 Krossen (1054 Patienten) eingeschlossen, davon wurden 631 Patienten (766 Krossen) in den folgenden fünf Jahren nachuntersucht. Die Patienten wurden in drei Gruppen randomisiert. In der Kontrollgruppe (G1) wurden 607 radikale Krossektomien durchgeführt. In der Gruppe G2 wurde in 292 Fällen zusätzlich die Fascia cribrosa übernäht. In der Gruppe G3 (490 Krossen) wurde nach radikaler Krossektomie das Endothel des Stumpfes invertierend übernäht. Ergebnisse: Bei der Nachuntersuchung wurden vier Gruppen unterschieden: regelrechte postoperative Verhältnisse, Krossenrezidiv mit oder ohne klinischer Relevanz, verbliebener Stumpf. In G1 wurden 30/311 (9,6%), in G2 10/176 (5,7%) und in G3 26/279 (9,3%) Neovaskularisationen mit und ohne klinische Relevanz gefunden Schlussfolgerung: Die Studie zeigt, dass die Krossenrezidivrate durch Neoangiogenese nach korrekter Krossektomie durch die Einrichtung einer Barriere über dem Stumpfendothel nicht signifikant gesenkt wird.

Immunophenotype of Peripheral Blood Lymphocytes in Dogs with Inflammatory Bowel Disease

Background

Inflammatory bowel disease (IBD) is common in dogs. Despite the known importance of intestinal lymphocytes in its pathogenesis, little is known about the role of peripheral blood lymphocytes (PBLs) in IBD.

Objectives

The aims of this study were (1) comparison of PBLs analyzed by flow cytometry (FCM) in IBD dogs and healthy controls and (2) comparison of PBLs in IBD dogs at the time of diagnosis and in dogs in clinical remission.

Animals

Whole blood samples of 19 IBD dogs at the time of diagnosis and blood samples of 6 dogs in clinical remission were collected. Ten healthy dogs served as controls.

Methods

In this prospective observational study, PBLs were analyzed with multicolor FCM by staining with a panel of anticanine and cross‐reactive monoclonal antibodies against T‐ and B‐cell differentiation antigens, including CD45, CD3, CD4, CD8α, CD8β, TCRαβ, TCRγδ, CD79αcy, and CD21.

Results

The IBD patients’ PBLs had significantly decreased percentages of TCRγδ⁺ T lymphocytes (median: healthy dogs, 3.32; IBD dogs, 0.97; P = 0.03) and CD21⁺ B cells (median: healthy dogs, 27.61; IBD dogs, 17.26; P = 0.04). There were no significant differences in PBLs between pretreatment and follow‐up samples.

Conclusions and Clinical Importance

The differences between PBLs in healthy and IBD dogs analyzed by FCM indicate an imbalance of lymphocytes with different immunologic functions and emphasize the potential value of this technique in a larger cohort of dogs. The PBLs did not differ between IBD dogs before treatment and clinically well‐controlled dogs after treatment.

Kinetics of fast changing intramolecular distance distributions obtained by combined analysis of FRET efficiency kinetics and time-resolved FRET equilibrium measurements

Detailed studies of the mechanisms of macromolecular conformational transitions such as protein folding are enhanced by analysis of changes of distributions for intramolecular distances during the transitions. Time-resolved Förster resonance energy transfer (FRET) measurements yield such data, but the more readily available kinetics of mean FRET efficiency changes cannot be analyzed in terms of changes in distances because of the sixth-power dependence on the mean distance. To enhance the information obtained from mean FRET efficiency kinetics, we combined the analyses of FRET efficiency kinetics and equilibrium trFRET experiments. The joint analysis enabled determination of transient distance distributions along the folding reaction both in cases where a two-state transition is valid and in some cases consisting of a three-state scenario. The procedure and its limits were tested by simulations. Experimental data obtained from stopped-flow measurements of the refolding of Escherichia coli adenylate kinase were analyzed. The distance distributions between three double-labeled mutants, in the collapsed transient state, were determined and compared to those obtained experimentally using the double-kinetics technique. The proposed method effectively provides information on distance distributions of kinetically accessed intermediates of fast conformational transitions induced by common relaxation methods.

Phenotypic characterization of canine intestinal intraepithelial lymphocytes in dogs with inflammatory bowel disease

Background

Many dogs suffering from inflammatory bowel disease (IBD) are presented to veterinary clinics. These patients are diagnosed based on a history of chronic gastrointestinal signs and biopsy‐confirmed histopathologic intestinal inflammation. Intestinal intraepithelial lymphocytes (IEL) are part of the first line of defense in the gastrointestinal immune system. Alterations in IEL subsets may play a role in the pathogenesis of IBD.

Hypothesis

The aim of this study was to characterize the phenotypes of IEL in dogs with IBD compared with healthy control dogs.

Animals

Intestinal intraepithelial lymphocytes subpopulations of control dogs (n = 5) obtained from endoscopic biopsies (EB) were compared to those obtained from full thickness biopsies (FTB) on the same day. In addition, the phenotypes of IEL from FTB of control dogs (n = 10) were compared with EB of IBD dogs (n = 10). Each participant was scored clinically using the canine inflammatory bowel disease activity index (CIBDAI), and all samples were graded histopathologically. Three‐color flow cytometry of isolated IEL was performed using monoclonal antibodies against T‐ and B‐lymphocyte subpopulations.

Results

No significant differences in the composition of IEL subpopulations were found in control dogs based on method of biopsy. The IBD dogs had significantly higher CIBDAI and histopathologic scores compared with control dogs and their IEL contained a significantly higher frequency TCRγδ T‐cells.

Conclusions and Clinical Importance

Endoscopic biopsies provide suitable samples for 3‐color flow cytometry when studying canine intestinal IEL and IBD patients show significant changes of major T‐cell subsets compared to healthy control dogs.

Chronische Beschwerden nach Stammvenenstripping

In der phlebologischen Literatur spielt die Pro-blematik in situ-belassenen Eingriffmaterials im OP-Gebiet keine nennenswerte Rolle. Wir berichten über eine 47-jährige Patientin, die sich zur operativen Therapie einer beiderseiti-gen Vena saphena parva-Stammvaricosis in unserer Klinik vorstellte. 20 Jahre zuvor waren an beiden Beinen Krossektomie und Vena saphena magna-Exhairese in einer auswärtigen Klinik durchgeführt worden. Supramalleolär persistierte über 20 Jahre eine Induration mit lokal starker Druckschmerzhaftigkeit, als deren Ursache sich im Zuge der jetzt erfolgten operativen Revision ein damals belassener Strippingkopf ergab. Der ungewöhnliche Fall zeigt, dass auch in der Phlebochirurgie an die Vollständigkeit des Instrumentariums gedacht werden sollte.

Evaluation of the distribution of distances between energy donors and acceptors by fluorescence decay

When transfer of electronic excitation energy occurs between a donor-acceptor pair by the Förster mechanism, the decay of fluorescence of the donor follows first-order kinetics, with a rate constant that depends on the distance from donor to acceptor. In a system that contains donor-acceptor pairs of different separations, the fluorescence decay of the donors will not be exponential, but will depend on the distribution function of donor-acceptor distances, f(r). Various approaches are outlined for the extraction of information about f(r) from the decay curve of donor fluorescence. Specifically, if a plausible expression with adjustable parameters is assumed for f(r), numerical methods can be used to evaluate the parameters that yield the closest fit between the observed decay curve and that calculated from the assumed f(r). The technique of fluorescence decay may prove to be useful for determination of distribution functions of end-to-end distances of polymers to the edges of which suitable donor-acceptor chromophore pairs have been attached.

Acroangiodermatitis Mali resulting from arteriovenous malformation: report of a case of Stewart-Bluefarb syndrome

We describe the rare Stewart-Bluefarb syndrome in a 15-year-old boy. This syndrome presents as a congenital arteriovenous malformation of the lower leg with multiple arteriovenous shunts accompanied by the benign acroangiodermatitis of Mali (pseudo-Kaposi's sarcoma). The clinical features of this disorder and the treatment options are reviewed.

Generalisiertes Arzneimittelexanthem nach Sklerotherapie mit dem chromatisierten Glyzerin Scleremo

Im Rahmen der Sklerosierungstherapie von Teleangiektasien und Retikulärvarizen sind systemische Therapiekomplikationen selten. Wir berichten über einen 68-jährigen Patienten mit einem generalisierten Exanthem 48 Stunden nach einer Sklerotherapie mit dem chromatisierten Glyzerin Scleremo®. Obwohl anamnestisch keine Typ-IV-Sensibilisierung bekannt war, zeigte die Epikutantestung eine relevante Sensibilisierung auf Kaliumdichromat und Kobalt. Wir stellten die Diagnose eines generalisierten Arzneimittelexanthems. Unter kurzfristiger Glukokortikoidtherapie und Allergenkarenz kam es zu einer Besserung.

Die Unverträglichkeitsreaktion auf Scleremo zeigt deutlich, dass unerwünschte, unerwartete, systemische Reaktionen bei klinisch üblicher Dosierung von Verödungsmitteln auftreten können. Dies sollte auch in der Patientenaufklärung berücksichtigt werden

Stripping bei klassischer operativer Versorgung einer Stammvarikosis der Vena saphena magna

Ziel: Vergleich dreier Stripping-Methoden der Vena saphena magna hinsichtlich intra- und postoperativer verfahrenstypischer Komplikationen sowie im Hinblick auf medizinische und kosmetische Ergebnisse. Patienten, Methode: An der prospektiv-randomisierten, farbduplexsonographisch-kontrollierten Studie nahmen 378 Patienten (453 operierte Beine) mit einer Stammveneninsuffizienz der Vena saphena magna (Stadium Hach II-III) teil, die an unserer Klinik operiert und nach ungefähr einem halben Jahr nachuntersucht worden waren. Sie wurden in drei Gruppen randomisiert: Nach klassischer Krossektomie erfolgte die stadiengerechte Teilsaphenektomie in Gruppe 1 mit einer PIN-Stripping-Sonde, in Gruppe 2 mittels konventionellem Stripping und in Gruppe 3 durch eine Kryosonde. Die drei Gruppen wurden hinsichtlich Handling, Komplikationen und Ergebnissen verglichen. Ergebnisse: Insgesamt zeigte sich eine statistisch signifikante (p <0,05) Überlegenheit der Kryosonde bei der intraoperativen Handhabung und der durchschnittlichen Operationsdauer, jedoch führte diese Methode etwas häufiger zu postoperativen Beschwerden (ohne statistische Signifikanz). Hinsichtlich der kosmetischen Ergebnisse (Besenreiser, Matting, subjektive Patientenzufriedenheit) und langfristigen Komplikationen (Sensibilitätsstörungen, Lymphödeme) waren nach sechs Monaten postoperativ keine signifikanten Unterschiede zwischen den drei Methoden festzustellen.

Pericallosal aneurysm simulating corpus callosum tumour

The MRI characteristics of an isolated subacute aneurysmal corpus callosum hematoma, without evidence of blood in cerebrospinal fluid (CSF) spaces or ventricles, have not been previously reported. This report highlights the difficulty of accurate diagnosis and treatment in a patient with an unusual ruptured pericallosal aneurysm simulating a corpus callosum tumour. Additionally we analyse the particular radiological configuration and appearance of blood products in this region.

Fast Collapse but Slow Formation of Secondary Structure Elements in the Refolding Transition of E.coli Adenylate Kinase

The various models proposed for protein folding transition differ in their order of appearance of the basic steps during this process. In this study, steady state and time-resolved dynamic non-radiative excitation energy transfer (FRET and trFRET) combined with site specific labeling experiments were applied in order to characterize the initial transient ensemble of Escherichia coli adenylate kinase (AK) molecules upon shifting conditions from those favoring denaturation to refolding and from folding to denaturing. Three sets of labeled AK mutants were prepared, which were designed to probe the equilibrium and transient distributions of intramolecular segmental end-to-end distances. A 176 residue section (residues 28-203), which spans most of the 214 residue molecule, and two short secondary structure chain segments including an alpha-helix (residues 169-188) and a predominantly beta-strand region (residues 188-203), were labeled. Upon fast change of conditions from denaturing to folding, the end-to-end distance of the 176 residue chain section showed an immediate collapse to a mean value of 26 A. Under the same conditions, the two short secondary structure elements did not respond to this shift within the first ten milliseconds, and retained the characteristics of a fully unfolded state. Within the first 10 ms after changes of the solvent from folding to denaturing, only minor changes were observed at the local environments of residues 203 and 169. The response of these same local environments to the shift of conditions from denaturing to folding occurred within the dead time of the mixing device. Thus, the response of the CORE domain of AK to fast transfer from folding to unfolding conditions is slow at all three conformational levels that were probed, and for at least a few milliseconds the ensemble of folded molecules is maintained under unfolding conditions. A different order of the changes was observed upon initiation of refolding. The AK molecules undergo fast collapse to an ensemble of compact structures where the local environment of surface probes seems to be native-like but the two labeled secondary structure elements remain unfolded.

Characterization of an infectious cDNA copy of the genome of a naturally occurring, avirulent coxsackievirus B3 clinical isolate

Group B coxsackieviruses (CVB) cause numerous diseases, including myocarditis, pancreatitis, aseptic meningitis and possibly type 1 diabetes. To date, infectious cDNA copies of CVB type 3 (CVB3) genomes have all been derived from pathogenic virus strains. An infectious cDNA copy of the well-characterized, non-pathogenic CVB3 strain GA genome was cloned in order to facilitate mapping of the CVB genes that influence expression of a virulence phenotype. Comparison of the sequence of the parental CVB3/GA population, derived by direct RT-PCR-mediated sequence analysis, to that of the infectious CVB3/GA progeny genome demonstrated that an authentic copy was cloned; numerous differences were observed in coding and non-coding sequences relative to other CVB3 strains. Progeny CVB3/GA replicated similarly to the parental strain in three different cell cultures and was avirulent when inoculated into mice, causing neither pancreatitis nor myocarditis. Inoculation of mice with CVB3/GA protected mice completely against myocarditis and pancreatitis induced by cardiovirulent CVB3 challenge. The secondary structure predicted for the CVB3/GA domain II, a region within the 5′ non-translated region that is implicated as a key site affecting the expression of a cardiovirulent phenotype, differs from those predicted for cardiovirulent and pancreovirulent CVB3 strains. This is the first report characterizing a cloned CVB3 genome from an avirulent strain.

Combined Minimal Invasive Techniques in Deep Supratentorial Intracerebral Haematomas

Minimal invasive techniques (MIT) like microscopy, stereotaxy, endoscopy and neuronavigation facilitate and improve neurosurgical results and reduce the operative trauma. We report the combined employment of these techniques and the results obtained in our department during the last 7 years in 95 consecutive patients with supratentorial deep located intracerebral haematomas (ICHs). Thirty-six deteriorating patients with deep ICHs under 30 cm (3) volume associated to intraventricular bleeding, were treated early (first 24 hours after bleeding) with neuronavigation guided stereotactic lysis, using multiplanar targets (1 to 3). Microsurgical clot aspiration through an enlarged burr-hole was frequently combined with endoscope- or neuronavigation-assisted evacuation within the first 6 hours after bleeding for the rest of the deteriorating patients with ICHs larger than 30 cm (3). A 1.2 cm narrow surgical corridor assured the least injury to vital cortical areas, tracts and blood vessels. In 86 cases the clots were adequately removed (non-measurable rest) with a reduced morbid mortality (13.8 and 8.6 as well as 23.3 and 16.9 for stereotactic and microscopic MIT, respectively). In our experience, the use of combined MIT adapted to the surgical urgency of the individual patient reduces the operative trauma and improves the accuracy for the access to the clot allowing an adequate haematoma evacuation and a satisfactory outcome in most of the cases.

Minimal Invasive Neurosurgery of Infiltrative Tumours Extending Around the Sellar Region: Advantage of Combined Methods

Most of the infiltrative tumoural lesions located around the sellar region compromise the cavernous sinus, cranial nerves, vascular neighboured structures and the hypothalamus. Minimal invasive neurosurgery (MIN) employing microsurgery, neuroendoscopy, neuronavigation and intraoperative radioscopy are reported to increase gross total tumour resection reducing the operative trauma. We combined at least 3 of these techniques in 32 patients with solid and 8 patients with cystic tumours of this region. Thirty tumours were approached in a transphenoidal manner, ten were via a single burr hole craniotomy in a transcortico-ventricular approach. In 36 cases the tumours were adequately removed with only six cases suffering a transitory and one with a permanent deterioration of a preoperatively diagnosed neurological deficit. In our experience, the use of combined techniques, particularly in these patients, reduces the operative trauma and improves the accuracy in planning the access, angle and extension of tumour removal. It also protects the patient from secondary damage to neighboured structures.

A general strategy for site-specific double labeling of globular proteins for kinetic FRET studies

Site-directed mutagenesis provides a straightforward means of creating specific targets for chemical modifications of proteins. This capability enhanced the applications of spectroscopic methods adapted for addressing specific structural questions such as the characterization of partially folded and transient intermediate structures of globular proteins. Some applications such as the steady state or time-resolved fluorescence resonance energy transfer (FRET) detection of the kinetics of protein folding require relatively large quantities (approximately 10-100 mg) of site-specific doubly labeled protein samples. Engineered cysteine residues are common targets for labeling of proteins. The challenge here is to develop methods for selective modification of one of two reactive sulfhydryl groups in a protein molecule. A general systematic procedure for selective labeling of each of two cysteine residues in a protein molecule was developed, using Escherichia coli adenylate kinase (AKe) as a model protein. Potential sites for insertion of cysteine residues were selected by examination of the crystal structure of the protein. A series of single-cysteine mutants was prepared, and the rates of the reaction of each engineered cysteine residue with a reference reagent [5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)] were determined. Two-cysteine mutants were prepared by selection of pairs of sites for which the ratio of this reaction rate constant was high (>80). The conditions for the selective labeling reaction were optimized. In a first cycle of labeling, the more reactive cysteine residue was labeled with a fluorescent probe (donor). The second probe was attached to the less reactive site under unfolding conditions in the second cycle of labeling. The doubly and singly labeled mutants retained full enzymatic activity and the capacity for a reversible folding-unfolding transition. High yields (70-90%) of the preparation of the pure, site-specific doubly labeled AK mutant were obtained. The procedure described herein is a general outline of procedures, which can meet the double challenge of both site specificity and large-scale preparation of doubly labeled proteins.

The natively helical chain segment 169-188 of Escherichia coli adenylate kinase is formed in the latest phase of the refolding transition

The refolding transition of Escherichia coli adenylate kinase (AK) was investigated by monitoring the refolding kinetics of a selected 20 residue helical segment in the CORE domain of the protein. Residues 169 and 188 were labeled by 1-acetamido-methyl-pyrene, and by bimane, respectively. The experiment combines double-jump stopped-flow fast mixing initiation of refolding and time-resolved Förster energy transfer spectroscopy for monitoring the conformational transitions (double-kinetics experiment). Two kinetic phases were found in the denaturant-induced unfolding of AK. In the first phase, the fluorescence quantum yields of both probes decreased. The distribution of the distances between them transformed from the native state's narrow distribution with the mean distance corresponding to the distance in the crystal structure, to a distribution compatible with an unordered structure. In the second, slow step of denaturation, neither the fluorescence parameters of the probes nor the distance distribution between them changed. This step appeared to be a transformation of the fast-folding species formed in the first phase, to the slow-folding species. Refolding of the fast-folding species of the denatured state of AK was also a two-phase process. During the first fast phase, within less than 5ms, the fluorescence emission of both probes increased, but the distance distribution between the labeled sites was unchanged. Only during the second slow refolding step did the intramolecular distance distribution change from the characteristic of the denatured state to the narrow distribution of the native state. This experiment shows that for the case of the CORE domain of AK, the large helical segment of residues 169-188 was not formed in the first compaction step of refolding. The helical conformation of this segment is established only in the second, much slower, refolding phase, simultaneously with the completion of the native structure.

A diverse family of proteins containing tumor necrosis factor receptor-associated factor domains

We have identified three new tumor necrosis factor-receptor associated factor (TRAF) domain-containing proteins in humans using bioinformatics approaches, including: MUL, the product of the causative gene in Mulibrey Nanism syndrome; USP7 (HAUSP), an ubiquitin protease; and SPOP, a POZ domain-containing protein. Unlike classical TRAF family proteins involved in TNF family receptor (TNFR) signaling, the TRAF domains (TDs) of MUL, USP7, and SPOP are located near the NH(2) termini or central region of these proteins, rather than carboxyl end. MUL and USP7 are capable of binding in vitro via their TDs to all of the previously identified TRAF family proteins (TRAF1, TRAF2, TRAF3, TRAF4, TRAF5, and TRAF6), whereas the TD of SPOP interacts weakly with TRAF1 and TRAF6 only. The TD of MUL also interacted with itself, whereas the TDs of USP7 and SPOP did not self-associate. Analysis of various MUL and USP7 mutants by transient transfection assays indicated that the TDs of these proteins are necessary and sufficient for suppressing NF-kappaB induction by TRAF2 and TRAF6 as well as certain TRAF-binding TNF family receptors. In contrast, the TD of SPOP did not inhibit NF-kappaB induction. Immunofluorescence confocal microscopy indicated that MUL localizes to cytosolic bodies, with targeting to these structures mediated by a RBCC tripartite domain within the MUL protein. USP7 localized predominantly to the nucleus, in a TD-dependent manner. Data base searches revealed multiple proteins containing TDs homologous to those found in MUL, USP7, and SPOP throughout eukaryotes, including yeast, protists, plants, invertebrates, and mammals, suggesting that this branch of the TD family arose from an ancient gene. We propose the moniker TEFs (TD-encompassing factors) for this large family of proteins.

Structure and dynamics of the alpha-lactalbumin molten globule: fluorescence studies using proteins containing a single tryptophan residue

The fluorescence properties of three variants of alpha-lactalbumin (alpha-LA) containing a single tryptophan residue were investigated under native, molten globule, and unfolded conditions. These proteins have levels of secondary structure and stability similar to those of the wild type. The fluorescence signal in the native state is dominated by that of W104, with the signal of W60 and W118 significantly quenched by the disulfide bonds in their vicinity. In the molten globule state, the magnitude of the fluorescence signal of W60 and W118 increases, due to the loss of rigid, specific side chain packing. In contrast, the magnitude of the signal of W104 decreases in the molten globule state, perhaps due to the protonation of H107 or quenching by D102 or K108. The solvent accessibilities of individual tryptophan residues were investigated by their fluorescence emission maximum and by acrylamide quenching studies. In the native state, the order of solvent accessibility is as follows: W118 > W60 > W104. This order changes to W60 > W104 > W118 in the molten globule state. Remarkably, the solvent accessibility of W118 in the alpha-LA molten globule is lower than that in the native state. The dynamic properties of the three tryptophan residues were examined by time-resolved fluorescence anisotropy decay studies. The overall rotation of the molecule can be observed in both the native and molten globule states. In the molten globule state, there is an increase in the extent of local backbone fluctuations with respect to the native state. However, the fluctuation is not sufficient to result in complete motional averaging. The three tryptophan residues in the native and molten globule states have different degrees of motional freedom, reflecting the folding pattern and dynamic heterogeneity of these states. Taken together, these studies provide new insight into the structure and dynamics of the alpha-LA molten globule, which serves as a prototype for partially folded proteins.

A permissive role for tumor necrosis factor in vascular endothelial growth factor-induced vascular permeability

Vascular endothelial growth factor (VEGF) induces both angiogenesis and an increase in vascular permeability, 2 processes that are considered to be important for both tumor growth and the delivery of drugs to the site of tumors. This study demonstrates that transmembrane expression of tumor necrosis factor (tmTNF) is up-regulated in the endothelium of a murine methylcholanthrene (meth A)-induced sarcoma in comparison to the adjacent normal dermal vasculature and is also present on cultivated human endothelial cells. It is further shown that tmTNF is required for VEGF-mediated endothelial hyperpermeability in vitro and in vivo. This permissive activity of TNF appears to be selective, because anti-TNF antibodies ablated the VEGF-induced permeability but not proliferation of cultivated human endothelial cells. Furthermore, tnf gene-deficient mice show no obvious defects in vascularization and develop normally but failed to respond to administration of VEGF with an increase in vascular permeability. Subsequent studies indicated that the tmTNF and VEGF signaling pathways converge at the level of a secondary messenger, the "stress-activated protein kinase-2" (SAPK-2)/p38: (1) up-regulated endothelial expression of tmTNF resulted in the continuous activation of SAPK-2/p38 in vitro, and (2) an inhibitor of SAPK-2/p38 activation abolished the vascular permeability activity of VEGF in vivo. In conclusion, the study's finding that continuous autocrine signaling by tmTNF sensitizes endothelial cells to respond to VEGF by increasing their vascular permeability provides new therapeutic concepts for manipulating vascular hyperpermeability.

A randomized and prospective study comparing treatment with high-dose intravenous immunoglobulin with monoclonal antibodies for rescue of kidney grafts with steroid-resistant rejection

BACKGROUND

The aim of this study was to compare the effectiveness of intravenous immunoglobulin (IVIg) versus monoclonal anti-CD3 as a treatment for steroid-resistant rejections. From January 1995 to June 1997, 30 patients were analyzed. They were randomized into two groups. Resistant rejections were diagnosed by core biopsy. Group A received 500 mg/ kg/day IVIg (Sandoglobulin) for 7 consecutive days, whereas group B received 5 mg/day of OKT3 for 14 consecutive days. Daily T cell CD3+ peripheral count was performed for 14 days for group B. The immunosuppression was similar for both groups. Cyclosporine was stopped during both treatments.

METHODS

Demographic factors, HLA mismatch, creatinine levels before and after treatment, and the incidence of rejections after treatment (up to 1 month) were taken into account for this study.

RESULTS

Data from different samples were compared using Fisher's exact test. Graft and patient survival were analyzed using the Kaplan-Meier method. The were no significant differences found in age, graft origin, HLA mismatch, or time of follow-up until the episode of rejection. Success was achieved for 11 (73.3%) of 15 of group A and 13 (86.6%) of 15 of group B (P=0.79). Creatinine levels before and after treatment were as follows: A, 2.99+/-1.30 mg/dl and 2.1+/-0.70 mg/dl versus B, 3.1+/-1.1 mg/dl and 2.5+/-0.8 mg/dl. Besides, we did not observe differences in the creatinine 1 month after treatment (A: 2.35+/-0.78 mg/dl; B: 2.51+/-1.10 mg/dl; P=0.66) nor in the third month (A: 1.83+/-0.58 mg/dl; B: 2.30+/-0.89 mg/dl; P=0.24). The incidence of rejections after treatment was 5 (46%) of 11 for group A and 9 (75%) of 12 for group B (P=0.4). The patient survival rates 2 years after treatment were 87 and 92% for A and B groups, respectively. Graft survival was identical (80% in both groups).

CONCLUSION

Should the favorable result presented in this report be confirmed in larger number of patients, IVIg could become the preferable choice of rejection treatment for steroid-resistant rejection because of a complete absence of the unwanted side effects commonly associated with OKT3.

Distributions of intramolecular distances in the reduced and denatured states of bovine pancreatic ribonuclease A. Folding initiation structures in the C-terminal portions of the reduced protein

The purpose of this investigation is to characterize the reduced state of RNase A (r-RNase A) in terms of (i) intramolecular distances, (ii) the sequence of formation of stable loops in the initial stages of folding, and (iii) the unfolding transitions induced by GdnHCl. This is accomplished by identifying specific subdomain structures and local and long-range interactions that direct the folding process of this protein and lead to the native fold and formation of the disulfide bonds. Eleven pairs of dispersed sites in the RNase A molecule were labeled with fluorescent donor and acceptor probes, and the distributions of intramolecular distances (IDDs) were determined by means of time-resolved dynamic nonradiative excitation energy transfer (TR-FRET) measurements. The mutants were designed to search for (a) a possible nonrandom fold of the backbone in the collapsed state and (b) possible loops stabilized by long-range interactions. It was found that, under folding conditions, (i) the labeled mutants of r-RNase A in refolding buffer (the R(N) state) exhibit features of specific (nonrandom) compact but very dispersed subdomain structures (indicated by short mean distances, broad IDDs, and a weak dependence of the mean distances on segment length), (ii) the backbone fold in the C-terminal beta-like portion of the molecule appears to adopt a native-like overall fold, (iii) the N-terminal alpha-like portion of the chain is separated from the C-terminal core by very large intramolecular distances, larger than those in the crystal structure, and (iv) perturbations by addition of GdnHCl reveal several conformational transitions in different sections of the chain. Addition of GdnHCl to the native disulfide-intact protein provided a reference state for the extent of expansion of intramolecular distances under denaturing conditions. In conclusion, r-RNase A under folding conditions (the R(N) state) is poised for the final folding step(s) with a native-like trace of the chain fold but a large separation between the two subdomains which is then decreased upon introduction of three of the four native disulfide cross-links.

Local and long-range interactions in the thermal unfolding transition of bovine pancreatic ribonuclease A

This research was undertaken to distinguish between local and global unfolding in the reversible thermal denaturation of bovine pancreatic ribonclease A (RNase A). Local unfolding was monitored by steady-state and time-resolved fluorescence of nine mutants in each of which a single tryptophan was substituted for a wild-type residue. Global unfolding was monitored by far-UV circular dichroism and UV absorbance. All the mutants (except F8W and D38W) exhibited high specific enzymatic activity, and their far-UV CD spectra were very close to that of wild-type RNase A, indicating that the tryptophan substitutions did not affect the structure of any of the mutants (excluding K1W and Y92W) under folding conditions at 20 degrees C. Like wild-type RNase A, the various mutants exhibited reversible cooperative thermal unfolding transitions at pH 5, with transition temperatures 2.5-11 degrees C lower than that of the wild-type transition, as detected by far-UV CD or UV absorbance. Even at 80 degrees C, well above the cooperative transition of all the RNase A mutants, a considerable amount of secondary and tertiary structure was maintained. These studies suggest the following two-stage mechanism for the thermal unfolding transition of RNase A as the temperature is increased. First, at temperatures lower than those of the main cooperative transition, long-range interactions within the major hydrophobic core are weakened, e.g., those involving residues Phe-8 (in the N-terminal helix) and Lys-104 and Tyr-115 (in the C-terminal beta-hairpin motif). The structure of the chain-reversal loop (residues 91-95) relaxes in the same temperature range. Second, the subsequent higher-temperature cooperative unfolding transition is associated with a loss of secondary structure and additional changes in the tertiary contacts of the major hydrophobic core, e.g., those involving residues Tyr-73, Tyr-76, and Asp-38 on the other side of the molecule. The hydrophobic interactions of the C-terminal loop of the protein are enhanced by high temperature, and perhaps are responsible for the preservation of the local structural environment of Trp-124 at temperatures slightly above the major cooperative transition. The results shed new light on the thermal unfolding transitions, generally supporting the thermal unfolding hypothesis of Burgess and Scheraga, as modified by Matheson and Scheraga.

Inhibition of death receptor-mediated gene induction by a cycloheximide-sensitive factor occurs at the level of or upstream of Fas-associated death domain protein (FADD)

In HeLa cells, induction of apoptosis and nuclear factor kappaB (NF-kappaB) activation initiated by TRAIL/Apo2L or the agonistic Apo1/Fas-specific monoclonal antibody anti-APO-1 require the presence of cycloheximide (CHX). Inhibition of caspases prevented TRAIL/anti-APO-1-induced apoptosis, but not NF-kappaB activation, indicating that both pathways bifurcate upstream of the receptor-proximal caspase-8. Under these conditions, TRAIL and anti-APO-1 up-regulated the expression of the known NF-kappaB targets interleukin-6, cellular inhibitor of apoptosis 2 (cIAP2), and TRAF1 (TRAF, tumor necrosis factor receptor-associate factor). In the presence of CHX, the stable overexpression of a deletion mutant of the Fas-associated death domain molecule FADD comprising solely the death domain of the molecule but lacking its death effector domain (FADD-(80-208)) led to the same response pattern as TRAIL or anti-APO-1 treatment. Moreover, the ability of death receptors to induce NF-kappaB activation was drastically reduced in a FADD-deficient Jurkat cell line. TRAIL-, anti-APO-1-, and FADD-(80-208)-initiated gene induction was blocked by a dominant-negative mutant of TRAF2 or the p38 kinase inhibitor SB203580, similar to tumor necrosis factor receptor-1-induced NF-kappaB activation. CHX treatment rapidly down-regulated endogenous cFLIP protein levels, and overexpression of cellular FLICE inhibitory protein (cFLIP) inhibited death receptor-induced NF-kappaB activation. Thus, a novel functional role of cFLIP as a negative regulator of gene induction by death receptors became apparent.

Determination of intramolecular distance distribution during protein folding on the millisecond timescale

A method for determination of transient (on the millisecond timescale) intramolecular distance distributions (IDDs) by time-resolved dynamic non-radiative excitation energy transfer measurements was developed. The time-course of the development of the IDD between residues 73 and 203 in the CORE domain of Escherichia coli adenylate kinase throughout refolding from the GuHCl-induced denatured state was determined. The mean of the apparent IDD reduced to a value close to its magnitude in the native protein, within 2 ms (the dead-time of the instrument). At that time the width of that distribution was rather large (16+/-2 A). The large width implies that the intramolecular diffusion coefficient of the labeled segment does not exceed 10(-7) cm(2)/second. In a second slower phase of the refolding transition, the width was reduced to its native value (6+/-4 A).

Design consideration and probes for fluorescence resonance energy transfer studies

Spectroscopic properties of two newly synthesized water-soluble thiol-reactive fluorescent probes, 7-(iodoacetamido)-coumarin-4-carboxylic acid (I-Cca) and N-iodoacetyl-beta-(2-naphthyl)alanine (I-Nal), were characterized using single cysteine mutants of Escherichia coli adenylate kinase. Together with two known water-soluble thiol-reactive dyes (Lucifer yellow iodoacetamide and 5-iodoacetamidosalicylic acid) and as well, tryptophan residues (either native or inserted into a protein by site directed mutagenesis), these probes can be arranged pairwise in a molecular tool set for studies of structural transitions in proteins by means of fluorescence resonance energy-transfer (FRET) experiments. A set of seven donor/acceptor pairs which allow determination of intramolecular distances and their distributions over the range 10-40 A in labeled protein derivatives is described. The charged groups present in the probes facilitate the conjugation reaction and improve postlabeling purification. General considerations for design of charged probes and site-directed labeling for applications of FRET methods in studies of protein structure and dynamics are presented.

[Modification of postoperative wound healing by showering]

Usually postoperative wounds are kept dry until the stitches are removed. In a prospective randomized study early water contact was allowed in order to test postoperative wound healing in 817 patients operated on for varicose veins. Regardless of whether the wounds were kept dry or had water contact with or without shower foam from the second postoperative day, no infection was registered.