Low-grade infections as a possible cause of arthrofibrosis after total knee arthroplasty.

PURPOSE: Arthrofibrosis after total knee arthroplasty represents a considerable burden for the patient and a therapeutic challenge for the practitioner. One possible cause discussed in the literature is a low-grade infection. This hypothesis should be examined within the scope of this retrospective study. PATIENTS AND METHODS: Nineteen patients with clinical symptoms of arthrofibrosis after primary total knee arthroplasty were examined between January, 1999 and January, 2012. Incorrect positioning was radiologically ruled out. All patients were examined clinically (score of Freeman as well as Blauth and Jäger), radiologically (component and leg alignment, patella height according to Insall and Salvati), microbiologically (culture-based procedures), molecular biologically (PCR) and histologically in the course of an open revision of the prosthesis. RESULTS: According to the score of Freeman et al. (1977), a highly significant improvement in pain (p = 0.007) and in the overall score (p = 0.003) was shown. The knee joint mobility did not change significantly (p = 0.795). PCR was negative in 17 patients. One patient showed a PCR-positive result of the synovial membrane for Corynebacterium spp., while Staphylococcus warneri was detected in the culture. Another patient had a positive result of synovia PCR for Enterococcus cecorum as well as Corynebacterium spp. However, this culture was sterile. In 16 patient samples, no bacterial growth was detectable. Two samples were not evaluable. The main histopathological findings were synovialitis and fibrosis. CONCLUSION: The hypothesis of low-grade-infection-induced arthrofibrosis after total knee arthroplasty could not be confirmed in this study. However, based on this small study population the conclusion needs to be confirmed by new and larger studies, ideally prospectively designed including a control group.

Virulence patterns of Staphylococcus aureus strains from nasopharyngeal colonization.

BACKGROUND: The prevalence of nasopharyngeal colonization with Staphylococcus aureus can reach 20-30% among the population, which can lead to invasive infection. AIM: To investigate the prevalence of colonization among different age groups, and analyse S. aureus strain-specific virulence patterns. METHOD: For analysis of the prevalence of colonization, groups consisting of newborns, healthy volunteers aged 5-60 years, and nursing home residents aged >80 years were examined with nasopharyngeal swabs. After S. aureus was cultured, genetic analysis and phenotypic virulence testing were performed by cell-based assays. FINDINGS: Among 924 volunteers, the overall colonization rate was approximately 30%, with a peak in subjects aged 5-10 years (49%). Neonates and subjects aged >80 years showed different distributions of clonal clusters. Overall, the strains of all age groups exhibited virulence characteristics that can contribute to the development of infection. In particular, the neonatal strains exhibited a high incidence of toxin genes that resulted in increased cytotoxic effects compared with the other strains tested. CONCLUSIONS: Colonizing strains showed a virulence profile in all age groups, which may lead to the establishment of invasive infection. Consequently, decolonization measures could be considered for selected patients depending on the risk of infection.

Larval sensilla of the moth Heliothis virescens respond to sex pheromone components.

Female-released sex pheromones orchestrate the mating behaviour of moths. Recent studies have shown that sex pheromones not only attract adult males but also caterpillars. Single sensillum recordings revealed that larval antennal sensilla of the moth Heliothis virescens respond to specific sex pheromone components. In search for the molecular basis of pheromone detection in larvae, we found that olfactory sensilla on the larval antennae are equipped with the same molecular elements that mediate sex pheromone detection in adult male moths, including the Heliothis virescens receptors 6 (HR6) and HR13, as well as sensory neurone membrane protein 1 (SNMP1). Thirty-eight olfactory sensory neurones were identified in three large sensilla basiconica; six of these are considered as candidate pheromone responsive cells based on the expression of SNMP1. The pheromone receptor HR6 was found to be expressed in two cells and the receptor HR13 in three cells. These putative pheromone responsive neurones were accompanied by cells expressing pheromone-binding protein 1 (PBP1) and PBP2. The results indicate that the responsiveness of larval sensilla to female-emitted sex pheromones is based on the same molecular machinery as in the antennae of adult males.

[Language Delay: What is the Prognosis of Late Bloomers?]. / Sprachentwicklungsverzögerung: Was wird aus Late Bloomern?

BACKGROUND: 30-50% of late talkers catch-up their language delay during the third year of life. So far it is unclear whether this is a permanent or an illusionary recovery. The aim of the study was to examine the further language development of late bloomers. METHOD: Language skills of 83 three-year-old children (16 late bloomers [LB], 29 late talkers [LT] with persistent language problems, 38 Non-LT) were assessed with a standardized language test. Before school entry formal language skills, expressive and receptive vocabulary and precursors of written language (verbal memory, phonological awareness, verbal information-processing speed) were assessed. RESULTS: At follow-up before school entry LB scored below Non-LT on phonological memory test. 31% of the LB in contrast to 3% of the Non-LT had slight language problems. 38% had received speech-language therapy. Nevertheless, no LB met the criteria of developmental language disorder. The language skills of LT with persistent language problems remained significantly below the level of LB and Non-LT. Every fourth of these children was language impaired. CONCLUSION: LB as a group are not at risk for later clinically relevant language disorders. However, their language abilities are often within the lower range of normal variation. Therefore, it is recommended to facilitate their language acquisition either by kindergarten training programs or by parent-directed intervention programs to provide a more stimulating environment.

[Characterisation of a Collective of Children with Early Language Delay, 'Late Talkers']. / Charakterisierung eines Kollektivs von Kindern mit früher Verzögerung im Spracherwerb "Late Talkers".

BACKGROUND: By considering their general development, 2-year-old children with delayed speech development (late -talkers, LT) were examined and described with respect to linguistic competence and hearing. METHODS: Initially, 50 monolingual German speaking LT (age: 23-28 months) were recruited. In addition to audiological tests (impedance testing, otoacoustic emissions, reaction audiometry), language development status test was performed (clinical impression during examination, expressive vocabulary: FRAKIS, receptive competence: SETK-2). RESULTS: After exclusion of 10 children with general retarded development (3 premature infants, 2 children with suspicion of autism and 2 children with infantile brain damage) 33 LTs with normal hearing were included. The expressive vocabulary (FRAKIS) of 82% of these 33 LTs were below the normal range. 39% showed deficits in language comprehension tests (SETK-2) although parental reports mentioned language comprehension problems in only 3 LT. No correlation was found between vocabulary (FRAKIS) and language comprehension (SETK-2). CONCLUSION: The clinical collective in this study showed severely affected children with a high percentage of other abnormalities and speech perception problems in many cases. Despite normal hearing, vocabulary and especially speech comprehension should also be tested. LT with language comprehension problems require early developmental psychological investigation in order to prevent language and general developmental limitations. Only in this way, remedial instruction adapted to the develop-mental level can be initiated.

Coxiella burnetii (Q fever) as a cause of community-acquired pneumonia during the warm season in Germany.

Q fever is a notifiable disease in Germany. The majority of the reported cases are related to outbreaks. The objective of our study was to evaluate the general role of Q fever in community-acquired pneumonia (CAP). We investigated respiratory samples and sera from 255 patients with CAP, who were enrolled into a CAPNETZ cohort in summer 2005. Altogether, our data showed a significant prevalence of Q fever as CAP (3·5%). If a patient's condition leads to a diagnostic test for Chlamydophila sp., Mycoplasma sp. or Legionella sp., then a Q fever diagnostic test should also be included. In particular, ELISA as a first diagnostic step is easy to perform. PCR should be performed at an early stage of the disease if no antibodies are detectable. Because of our highly promising findings we suggest performing PCR in respiratory samples.

[Language comprehension in late talkers]. / Sprachverständnis bei Late Talkers.

BACKGROUND: Late talkers (LTs) show very different courses of language development. The aim of this study was to examine whether subgrouping LTs in terms of language comprehension could allow the identification of specific subtypes with different prognoses. PATIENTS AND METHODS: Amongst other assessment strategies, standardized language (SETK-2, SETK 3-5), general nonverbal development (MFED, SON-R 2½-7) and hearing tests (TOAE) were used to examine 48 LTs at the ages of 25 and 37 months. RESULTS: Deficits in language comprehension were recorded for 38 % of the LTs. LTs with and without impaired language comprehension differed only slightly in terms of their further language and nonverbal development, as well as in terms of anamnestic data. Comprehension of words but not of sentences proved to be a predictor of later speech impairments. CONCLUSION: Classification of LTs based on the comprehension of single words, but not of sentences or general language comprehension, at the age of 25 months can define subgroups of children with different prognoses. However, this only leads to marginal improvements in the predicted development of LTs, since substantial impairment of word comprehension is rarely observed.

[Language development between the german preventive paediatric examinations at the age of 2 and 3 in children with and without language delay]. / Sprachentwicklung von der U7 bis zur U7a bei Kindern mit und ohne Sprachentwicklungsverzögerungen.

At the beginning the course of language acquisition has a high degree of variability and it is unclear so far, at what age language delay is of clinical relevance. The present study addresses the question whether language skills at the age of 2 years allow prognostic statements and whether children with language delay at this age, are to be considered as children of risk.Starting from birth announcements children of average (n=42), borderline (n=28) and below-average stage of language development (n=50) were recruited. The language skills were assessed at the age of 2 (25+0.6 months) and 3 years (37+0.6 months) using standardized language tests.The correlation between the global stage of language development at the age of 2 and 3 years was strong (rsp=0.78, p<0.001). At 3 years of age one third of the former late talkers reached language abilities within the normal range (late bloomers), one third showed language difficulties and the last third met the criteria of specific language impairment. The risk for language difficulties was increased in these children to the 13-fold. Even the late bloomers scored significantly lower in the language test compared to the control children.From the third year of live language development is relatively stable, and language skills at the age of 2 allow a prediction of the stage of language development one year later. Late talkers are at high risk for persistent language difficulties. A general language screening at the age of 2 years would enable an early identification of children at risk and an early parent-based intervention.

The urinary antibiotic 5-nitro-8-hydroxyquinoline (Nitroxoline) reduces the formation and induces the dispersal of Pseudomonas aeruginosa biofilms by chelation of iron and zinc.

Since cations have been reported as essential regulators of biofilm, we investigated the potential of the broad-spectrum antimicrobial and cation-chelator nitroxoline as an antibiofilm agent. Biofilm mass synthesis was reduced by up to 80% at sub-MIC nitroxoline concentrations in Pseudomonas aeruginosa, and structures formed were reticulate rather than compact. In preformed biofilms, viable cell counts were reduced by 4 logs at therapeutic concentrations. Complexation of iron and zinc was demonstrated to underlie nitroxoline's potent antibiofilm activity.

First confirmed autochthonous case of human Babesia microti infection in Europe.

A 42-year-old female patient with acute myeloid leukemia presented with fever and heavy chest pain after her first cycle of specific chemotherapy. Acute myocardial infarction was excluded, but surprisingly, parasitic inclusions in erythrocytes became obvious in Pappenheim and Giemsa-stained peripheral blood smears. The patient did not remember a tick bite but acknowledged having received several blood transfusions in her recent medical history. Suspicion of malaria was ruled out by use of a dip-stick test. The diagnosis of Babesia microti infection was finally established by specific polymerase chain reaction (PCR). Six weeks after initiation of specific treatment, PCR turned negative and a positive immunoflourescence assay (IFA) with an IgG titer of 1:128 indicated seroconversion. Subsequent screening of donors involved in the transfusion of blood products to the patient demonstrated borderline reactivity for Babesia microti (IgG-titer 1:32) in 1 out of 44 individuals. Neither the patient nor the positively tested blood donor had travelled to North America or Asia. Therefore, this is the first confirmed autochthonous human infection in Europe.

[Early identification of developmental language disorders--predictive value of the German version of the CDI--infant form (ELFRA-1)]. / Prognostische Validität des ELFRA-1 bei der Früherkennung von Sprachentwicklungsstörungen.

BACKGROUND: Early identification of developmental language disorders is a precondition for early intervention and therefore of high clinical relevance. The ELFRA-1 was constructed to identify children at risk for language disorders in the context of the routine examination of children at the age of 12 months. The aim of the study was to determine the predictive validity of this screening tool. SUBJECTS AND METHOD: 121 parents completed the questionnaire for their 12 months old children. One year later the language development was assessed by means of the ELFRA-2, the German version of the CDI for two year old children. RESULTS: 63% of the children were correctly classified. The sensitivity amounted to 52% and the specificity to 65%. The RATZ-index (relative improvement of the hit rate in comparison to the random hit rate) was 23%, which has to be considered as unsatisfying. Improvement of language abilities were less likely in boys compared to girls and in cases of low educational background of the mother. CONCLUSIONS: The prognostic validity of the ELFRA-1 is insufficient and too low to identify children at risk for later language impairment. The screening overlooked too many late talkers and classified too many normally developed children as language impaired. The ELFRA-1 can not be recommended as a useful method for the early identification of language impaired children at the age of 12 months.

[Validity of a short form of the ELFRA-2 (German Version of the CDI-Toddler Form) for early identification of late talkers]. / Diagnostische Zuverlässigkeit einer Kurzversion des Elternfragebogens ELFRA-2 zur Früherkennung von Sprachentwicklungsverzögerungen.

BACKGROUND: Parents' questionnaires are assumed to be reliable instruments for early identification of language retardation. The general use of the ELFRA-2 in practice, however, is limited by its length. The goal of the study was to construct and to evaluate a short version. SUBJECTS AND METHOD: The ELFRA-2 was sent to 1397 parents shortly before their child's second birthday. The return rate of the questionnaire was 71%. Questionnaires of monolingual German speaking children were included in the study (n=866) and randomly divided into two samples. From the first sample the most informative word categories were extracted by means of regression analysis and were used to compose a short form. With the second independent sample the validity of the short version was determined. RESULTS: By means of stepwise regression analysis within the first sample a short version consisting of 42 items was developed. The correlation between scores of the short and the long version was high (r=0.95) and the classification (no language retardation vs. late talker) was congruent for most children. The sensitivity and the specifity of the short form were 83% and 97%, respectively. For the prediction of language impairment at the age of three years the short and the long version reached similar detection rates. CONCLUSIONS: The results show that the validity of the short and the long form are comparable with respect to detection of late talkers. The time necessary to complete the short version allows its application during standard check-up examinations of children at the age of two years, and also to immediately discuss its result with the parents. Before the short form can be applied in pediatric practice, however, a standardization is necessary.

Calcium responses to pheromones and plant odours in the antennal lobe of the male and female moth Heliothis virescens.

In male moths, the primary olfactory integration centre, the antennal lobe, consists of two systems. The macroglomerular complex processes pheromone information, while the ordinary glomeruli process plant odour information. Females lack a macroglomerular complex. We measured the spatial representation of odours using in-vivo optical recording. We found that: (1) pheromone substances elicited activity exclusively in the MGC. No response was found in female antennal lobes. (2) Plant odours elicited combinatorial activity patterns in the ordinary glomeruli in both males and females. No response was found in the MGC of male moths. (3) A clean air puff often led to activity, in both males and females, suggesting that mechano-sensory information is also processed in the antennal lobe. (4) With an interstimulus interval of 5 or 10 s, strongly activated glomeruli were able to follow the temporal structure of the stimulus, while others lost their phase-locking. Some glomeruli showed "off" responses. These properties were odour dependent. This confirms and extends previous studies, showing the functional significance of the two subsystems for processing olfactory information. Pheromones are coded in a combinatorial manner within the macroglomerular complex, with each glomerulus corresponding to one information channel. Plant odours are coded in an across-glomeruli code in the ordinary glomeruli.

The spatial representation of chemical structures in the antennal lobe of honeybees: steps towards the olfactory code.

Odours are represented by specific ensembles of activated glomeruli in a combinatorial manner within the olfactory bulb of vertebrates or the antennal lobe (AL) of insects. Here, we optically measured glomerular calcium activities in vivo in the honeybee Apis mellifera during olfactory stimulation with 36 pure chemicals differing systematically in carbon chain length (C-5-10) and functional group (aldehyde, ketone, alcohol, carboxylic acid and alkane). We show their glomerular representations in 38 morphologically identified glomeruli out of the honeybee's 160. We measured the molecular receptive range of identified glomeruli averaging up to 21 individuals. Of the 38 glomeruli measured, 23 show maximal activity in a specific range of chain length. Glomeruli preferentially responding to a functional group are also always broadly tuned to particular chain lengths. Furthermore, glomeruli with similar response spectra are often direct neighbours. The results allow conclusions about the interactions between olfactory receptors and odour molecules, and about the AL network.

The glomerular code for odor representation is species specific in the honeybee Apis mellifera.

Odors are coded by glomerular activity patterns in the insect antennal lobe (AL) and in the mammalian olfactory bulb. We measured glomerular responses to 30 different odors in the AL of honeybees using calcium-sensitive dyes. By subsequently staining glomeruli and identifying individual glomerular outlines, we were able to compare the patterns between animals. Regardless of whether the odors were mixtures or pure substances, environmental odors or pheromones, their representations were highly conserved among individuals. Therefore, it may be possible to create a functional atlas of the AL in which particular molecular receptive ranges are attributed to each glomerulus.