Controlled experiment finds no detectable citation bump from Twitter promotion.

Multiple studies across a variety of scientific disciplines have shown that the number of times that a paper is shared on Twitter (now called X) is correlated with the number of citations that paper receives. However, these studies were not designed to answer whether tweeting about scientific papers causes an increase in citations, or whether they were simply highlighting that some papers have higher relevance, importance or quality and are therefore both tweeted about more and cited more. The authors of this study are leading science communicators on Twitter from several life science disciplines, with substantially higher follower counts than the average scientist, making us uniquely placed to address this question. We conducted a three-year-long controlled experiment, randomly selecting five articles published in the same month and journal, and randomly tweeting one while retaining the others as controls. This process was repeated for 10 articles from each of 11 journals, recording Altmetric scores, number of tweets, and citation counts before and after tweeting. Randomization tests revealed that tweeted articles were downloaded 2.6-3.9 times more often than controls immediately after tweeting, and retained significantly higher Altmetric scores (+81%) and number of tweets (+105%) three years after tweeting. However, while some tweeted papers were cited more than their respective control papers published in the same journal and month, the overall increase in citation counts after three years (+7% for Web of Science and +12% for Google Scholar) was not statistically significant (p > 0.15). Therefore while discussing science on social media has many professional and societal benefits (and has been a lot of fun), increasing the citation rate of a scientist's papers is likely not among them.

Prevention and treatment of cancer associated venous thromboembolism - interdisciplinary consensus.

The increasing volume of the data and experience with direct oral anticoagulants (DOACS) in the primary and secondary prevention of venous thromboembolism in oncologic patients (CAVTE) has recently lead to changes in several international guidelines. We reflect these changes within the conditions in Slovak republic. In the primary prevention of CAVTE we recognise oncosurgical patients and nonsurgical patients: hospitalised and out patients. Low molecular weight heparins are still dominant in the primary prevention of CAVTE. Regarding the treatment and the secondary prevention of CAVTE, we recommend always to consider the possibility to use DOACs as they proved to be non inferior to LMWH. However, LMWH should be prefered over DOACs as well as over warfarin (VKA) in all patients who are in a clinically unstable condition with the high risk of bleeding and/or interaction with the systemic treatment. Primarily in the patients with intraluminal tumours of the upper part of the gastrointestinal tract and genitourinary tumours with the high risk of bleeding. As for the lack of data, LMWH are still preferd also in patients with primary tumours and metastatic disease of the central nervous system and in hemato oncology.

Analysis of von Willebrand Disease in the "Heart of Europe".

Background von Willebrand disease (VWD) is a genetic bleeding disorder caused by defects of von Willebrand factor (VWF), quantitative (type 1 and 3) or qualitative (type 2). The laboratory phenotyping is heterogenic making diagnosis difficult. Objectives Complete laboratory analysis of VWD as an expansion of the previously reported cross-sectional family-based VWD study in the Czech Republic (BRNO-VWD) and Slovakia (BRA-VWD) under the name "Heart of Europe," in order to improve the understanding of laboratory phenotype/genotype correlation. Patients and Methods In total, 227 suspected VWD patients were identified from historical records. Complete laboratory analysis was established using all available assays, including VWF multimers and genetic analysis. Results A total of 191 patients (from 119 families) were confirmed as having VWD. The majority was characterized as a type 1 VWD, followed by type 2. Multimeric patterns concordant with laboratory phenotypes were found in approximately 83% of all cases. A phenotype/genotype correlation was present in 84% (77% type 1, 99% type 2, and 61% type 3) of all patients. Another 45 candidate mutations (23 novel variations), not found in the initial study, could be identified (missense 75% and truncating 24%). An exon 1-3 gene deletion was identified in 14 patients where no mutation was found by direct DNA sequencing, increasing the linkage up to 92%, overall. Conclusion This study provides a cross-sectional overview of the VWD population in a part of Central Europe. It is an addition to the previously published BRNO-VWD study, and provides important data to the International Society of Thrombosis and Haemostasis/European Association for Haemophilia and Allied Disorders VWD mutation database with identification of novel causal mutations.

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.

County-Level Records for Culex stigmatosoma and Culex thriambus in Texas.

Populations of Culex stigmatosoma and Cx. thriambus have been documented in the southwestern USA with a southward range extension to northern South America and Central America, respectively. Studies conducted in California indicate both species are potential vectors of West Nile virus. However, vector competence studies are lacking for other parts of the USA. During a multicounty regional surveillance study west of San Antonio, Texas, multiple errors were observed in the Texas distributional literature of these species. These errors involved incorrect distributional information in Texas and US publications. Evidence to correct these errant records was found upon further analysis of Texas literature and curated specimens. Therefore, the aims of this study were to present that evidence and then combine the corrected records with additional records from the Texas Department of State Health Services and from larval collections made during other Texas surveillance studies.

Real-world effectiveness and safety of daratumumab, bortezomib and dexamethasone in relapsed/refractory multiple myeloma in Slovakia.

Real-world data on regimens for relapsed/refractory multiple myeloma (RRMM) are limited. Daratumumab in combination with bortezomib and dexamethasone is a promising new treatment. The aim of this analysis was to assess the outcomes of daratumumab-bortezomib-dexamethasone (DVd) combination for the treatment of patients with RRMM in a real-world setting. All consecutive RRMM patients who received at least two cycles of DVd treatment between December 2016 and July 2020 were identified. We analyzed the clinical characteristics and survival of 47 patients treated at 7 Slovak centers outside of the clinical trials. The median age was 65 years (range, 35 to 83). The median (range) number of lines of therapy per patient was 3 (2-6). All patients were previously exposed to PIs (proteasome inhibitors) and IMIDs (immunomodulatory drugs), the majority of patients (70.2%) had double refractory (IMIDs and PI) disease and 72.3% of patients were refractory to their last therapy. Most patients presented with high-risk characteristics, including 25.6% adverse cytogenetics and 25.5% extramedullary disease. The majority of patients responded with an overall response rate of 78%, we found complete response in 3, very good partial response in 22, partial response in 12, minor response or stable disease in 9, and progressive disease in 1 patient. After a median follow-up period of 8 months, the median progression-free survival was 10 months. There was a longer progression-free survival in those with 2 vs. >2 prior treatments, with equally good effectivity in standard-risk and high-risk cytogenetic groups. The adverse events were usually mild, none leading to permanent drug interruptions. Daratumumab-bortezomib-based combinations are efficacious and safe regimens in RRMM patients in the real-world setting. This is the first analysis in Slovakia addressing the DVd combination outside of the clinical trial setting.

Use of Fludarabine for the Treatment of Indolent Lymphoma with Chylothorax.

BACKGROUND: Although chylothorax is rare in patients with malignant lymphoma, it has been reported in cases with mediastinal lymphadenopathy, a bulky retroperitoneal mass, or thoracic ducts blocked by lymphocytes in chronic lymphocytic leukemia (CLL). The clinical picture is not specific. Patients become more immunocompromised and malnourished after repeated evacuations. Chylothorax is usually diagnosed when the triglyceride level is > 1.24 mmol/l and the cholesterol level is < 5.18 mmol/ l in the effusion. Chemotherapy or radiotherapy of the associated malignant tumors has been used as the first-line treatment of malignant chylothorax. The responses of chylothorax after 3-8 chemotherapy courses have been described. A few cases of indolent lymphoma associated with chylothorax that were treated with fludarabine-based chemotherapies with various outcomes have been published. Total parenteral nutrition or a low-fat diet combined with ingestion of medium-chain triglycerides can accelerate remission of chylothorax. OBSERVATION: This study presents two cases with chylothorax associated with a bulky abdominal mass in relapsed CLL and newly diagnosed follicular lymphoma, respectively. No further evacuations were required after one and three courses of fludarabine plus cyclophosphamide with/without rituximab in the patients with CLL and follicular lymphoma, respectively. Chylothorax disappeared after five courses, and a partial or complete response of malignant lymphoma was achieved. The response lasted for 30 months in the patient with CLL and has persisted throughout maintenance therapy with rituximab in the patient with follicular lymphoma. CONCLUSION: Limited experience indicates that fludarabine-based regimes can result in rapid regression of chylothorax, in addition to treating indolent lymphoma, which prevents patients becoming more malnourished and immunocompromised. Key words: lymphoma - fludarabine - chylothorax The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 2. 2. 2018 Accepted: 20. 5. 2018.

[Myositis Ossificans Traumatica in the Craniocervical Junction: A Case Report and Review of Literature]. / Myositis ossificans traumatica im kraniozervikalen Übergang ­ Fallbericht und Literaturübersicht.

Background Myosits ossificans (MO) is a rare but important differential diagnosis for a heterotrophic bony tumor in the muscles. It is often misdiagnosed as a malignant tumor. With a previous trauma the diagnosis is myositis ossificans traumatic (MOT). In most cases, it is benign and predominantly seen in the big muscles. But there can be malignant etiologies too. Case Description We report a rare case of MO in the muscle of the craniocervical junction. This 37-year-old woman had a riding accident years ago. Because of persisting pain and cervical dysfunction, we did a total resection. Clinical Implications MOT is a benign tumor that can be treated conservative in most cases. In case of persistent pain or neurological deficits, and especially for securing diagnosis, surgical resection is recommended.

The Doryctinae (Braconidae) of Costa Rica: genera and species of the tribe Heterospilini.

A comprehensive taxonomic study is presented for the four genera and 286 species of the doryctine tribe Heterospilini occurring in Costa Rica. The tribe is represented almost entirely by the 280 species of the genus Heterospilus Haliday. Keys for identification of the genera and species are provided and the genera and species are described and illustrated. An interactive key to the species of Heterospilus also was prepared using Lucid Builder. The following new genus and species are described from Costa Rica: Paraheterospilus gen. n., P. ceciliaensis sp. n., P. eumekus sp. n., P. wilbotgardus sp. n., Heterospilus achi sp. n., H. achterbergi sp. n., H. aesculapius sp. n., H. agujas sp. n., H. agujasensis sp. n., H. alajuelus sp. n., H. albocoxalis sp. n., H. alejandroi sp. n., H. amuzgo sp. n., H. angelicae sp. n., H. angustus sp. n., H. aphrodite sp. n., H. apollo sp. n., H. arawak sp. n., H. areolatus sp. n., H. artemis sp. n., H. athena sp. n., H. attraholucus sp. n., H. aubreyae sp. n., H. austini sp. n., H. azofeifai sp. n., H. bacchus sp. n., H. barbalhoae sp. n., H. bennetti sp. n., H. bicolor sp. n., H. boharti sp. n., H. borucas sp. n., H. braeti sp. n., H. brethesi sp. n., H. breviarius sp. n., H. brevicornus sp. n., H. bribri sp. n., H. brullei sp. n., H. bruesi sp. n., H. cabecares sp. n., H. cacaoensis sp. n., H. cachiensis sp. n., H. cameroni sp. n., H. cangrejaensis sp. n., H. careonotaulus sp. n., H. caritus sp. n., H. carolinae sp. n., H. cartagoensis sp. n., H. catiensis sp. n., H. catorce sp. n., H. cero sp. n., H. chaoi sp. n., H. chilamatensis sp. n., H. chocho sp. n., H. chorotegus sp. n., H. chorti sp. n., H. cinco sp. n., H. cocopa sp. n., H. colliletus sp. n., H. colonensis sp. n., H. complanatus sp. n., H. conservatus sp. n., H. cora sp. n., H. corcovado sp. n., H. corrugatus sp. n., H. costaricensis sp. n., H. cressoni sp. n., H. cuatro sp. n., H. curtisi sp. n., H. cushmani sp. n., H. dani sp. n., H. demeter sp. n., H. dianae sp. n., H. diecinueve sp. n., H. dieciocho sp. n., H. dieciseis sp. n., H. diecisiete sp. n., H. diez sp. n., H. doce sp. n., H. dos sp. n., H. dulcus sp. n., H. eberhardi sp. n., H. ektorincon sp. n., H. emilius sp. n., H. empalmensis sp. n., H. enderleini sp. n., H. escazuensis sp. n., H. fahringeri sp. n., H. fischeri sp. n., H. flavidus sp. n., H. flavisoma sp. n., H. flavostigmus sp. n., H. foersteri sp. n., H. fonsecai sp. n., H. fournieri sp. n., H. gahani sp. n., H. garifuna sp. n., H. gauldi sp. n., H. golfodulcensis sp. n., H. gouleti sp. n., H. granulatus sp. n., H. grisselli sp. n., H. guanacastensis sp. n., H. guapilensis sp. n., H. hachaensis sp. n., H. halidayi sp. n., H. hansoni sp. n., H. hansonorum sp. n., H. haplocarinus sp. n., H. hedqvisti sp. n., H. hera sp. n., H. heredius sp. n., H. hespenheidei sp. n., H. holleyae sp. n., H. huddlestoni sp. n., H. huetares sp. n., H. hypermekus sp. n., H. itza sp. n., H. ixcatec sp. n., H. ixil sp. n., H. jabillosensis sp. n., H. jakaltek sp. n., H. janzeni sp. n., H. jennieae sp. n., H. jonmarshi sp. n., H. jupiter sp. n., H. kellieae sp. n., H. kiefferi sp. n., H. kikapu sp. n., H. kulai sp. n., H. kuna sp. n., H. lapierrei sp. n., H. lasalturus sp. n., H. laselvus sp. n., H. leenderti sp. n., H. leioenopus sp. n., H. leiponotaulus sp. n., H. lenca sp. n., H. levis sp. n., H. leviscutum sp. n., H. levitergum sp. n., H. limonensis sp. n., H. longinoi sp. n., H. longisulcus sp. n., H. longius sp. n., H. luteogaster sp. n., H. luteoscutum sp. n., H. luteus sp. n., H. macrocarinus sp. n., H. macrocaudatus sp. n., H. magnus sp. n., H. malaisei sp. n., H. mam sp. n., H. maritzaensis sp. n., H. mars sp. n., H. masneri sp. n., H. masoni sp. n., H. mellosus sp. n., H. menkei sp. n., H. mercury sp. n., H. milleri sp. n., H. miskito sp. n., H. mixtec sp. n., H. monteverde sp. n., H. mopanmaya sp. n., H. muertensis sp. n., H. muesebecki sp. n., H. nahua sp. n., H. neesi sp. n., H. nemestrinus sp. n., H. nephilim sp. n., H. nephus sp. n., H. nigracapitus sp. n., H. nigragonatus sp. n., H. nigricoxus sp. n., H. nixoni sp. n., H. noyesi sp. n., H. nueve sp. n., H. nunesi sp. n., H. once sp. n., H. orbitus sp. n., H. orosi sp. n., H. paloverde sp. n., H. pappi sp. n., H. parkeri sp. n., H. parvus sp. n., H. pech sp. n., H. penosa sp. n., H. petiolatus sp. n., H. petralbus sp. n., H. phaeocoxus sp. n., H. phaeoskelus sp. n., H. pharkidodus sp. n., H. phytorius sp. n., H. pitillaensis sp. n., H. poqomchi sp. n., H. poqomom sp. n., H. puertoviejoensis sp. n., H. puntarensis sp. n., H. qanjobal sp. n., H. quickei sp. n., H. quitirrisi sp. n., H. racostica sp. n., H. rama sp. n., H. ramirezi sp. n., H. ratzeburgi sp. n., H. reagani sp. n., H. reinhardi sp. n., H. retheospilus sp. n., H. rhabdotus sp. n., H. ricacosta sp. n., H. rinconensis sp. n., H. robbieae sp. n., H. rohweri sp. n., H. rojasi sp. n., H. romani sp. n., H. rugosus sp. n., H. sabrinae sp. n., H. saminae sp. n., H. sanjosensis sp. n., H. santarosensis sp. n., H. sanvitoensis sp. n., H. saturn sp. n., H. seis sp. n., H. sergeyi sp. n., H. sharkeyi sp. n., H. shawi sp. n., H. shenefelti sp. n., H. shonan sp. n., H. siete sp. n., H. similis sp. n., H. sinuatus sp. n., H. smithi sp. n., H. spiloheterus sp. n., H. staryi sp. n., H. stelfoxi sp. n., H. strazanaci sp. n., H. sumo sp. n., H. szepligeti sp. n., H. terrabas sp. n., H. thereospilus sp. n., H. tobiasi sp. n., H. tolupan sp. n., H. townesi sp. n., H. trece sp. n., H. tres sp. n., H. tricolor sp. n., H. trienta sp. n., H. tuberculatus sp. n., H. turrialbaensis sp. n., H. tzutujil sp. n., H. ugaldei sp. n., H. uno sp. n., H. variabilis sp. n., H. veinte sp. n., H. veintidos sp. n., H. veintitres sp. n., H. veintiuno sp. n., H. vierecki sp. n., H. villegasi sp. n., H. vittatus sp. n., H. vulcanus sp. n., H. wahli sp. n., H. warreni sp. n., H. washingtoni sp. n., H. wesmaeli sp. n., H. whartoni sp. n., H. whitfieldi sp. n., H. wildi sp. n., H. wilkinsoni sp. n., H. wrightae sp. n., H. xanthus sp. n., H. xerxes sp. n., H. xinca sp. n., H. yaqui sp. n., H. ypsilon sp. n., H. zapotec sp. n., H. zeus sp. n., H. zitaniae sp. n., H. zoque sp. n., H. zunigai sp. n., H. zurquiensis sp. n. One new combination is proposed, Pioscelus costaricensis (Marsh) comb. n.

Fast-evolving homoplastic traits are best for species identification in a group of neotropical wasps.

Biological characters can be employed for both taxonomy and phylogenetics, but is conscripting characters for double duty a good idea? We explore the evolution of characters designed for taxonomic diagnosis in Costa Rican heterospiline wasps, a hyperdiverse lineage of parasitoid Braconidae, by mapping them to a robust multi-locus molecular phylogeny. We discover a strong positive relationship between the amount of evolutionary change a character undergoes and how broadly useful the characters are in the context of an interactive identification key--e.g., how evenly the character states are distributed among taxa. The empirical finding that fast characters are the most useful for species identification supports the idea that characters designed for taxonomic diagnoses are likely to underperform--or be positively misleading--in phylogenetic analyses.

Draft genome of the globally widespread and invasive Argentine ant (Linepithema humile).

Ants are some of the most abundant and familiar animals on Earth, and they play vital roles in most terrestrial ecosystems. Although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. Here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive Argentine ant (Linepithema humile), which was accomplished using a combination of 454 (Roche) and Illumina sequencing and community-based funding rather than federal grant support. Manual annotation of >1,000 genes from a variety of different gene families and functional classes reveals unique features of the Argentine ant's biology, as well as similarities to Apis mellifera and Nasonia vitripennis. Distinctive features of the Argentine ant genome include remarkable expansions of gustatory (116 genes) and odorant receptors (367 genes), an abundance of cytochrome P450 genes (>110), lineage-specific expansions of yellow/major royal jelly proteins and desaturases, and complete CpG DNA methylation and RNAi toolkits. The Argentine ant genome contains fewer immune genes than Drosophila and Tribolium, which may reflect the prominent role played by behavioral and chemical suppression of pathogens. Analysis of the ratio of observed to expected CpG nucleotides for genes in the reproductive development and apoptosis pathways suggests higher levels of methylation than in the genome overall. The resources provided by this genome sequence will offer an abundance of tools for researchers seeking to illuminate the fascinating biology of this emerging model organism.

Z-osteotomy in hallux valgus: clinical and radiological outcome after Scarf osteotomy.

Correction osteotomies of the first metatarsal are common surgical approaches in treating hallux valgus deformities whereas the Scarf osteotomy has gained popularity. The purpose of this study was to analyze short- and mid-term results in hallux valgus patients who underwent a Scarf osteotomy. The subjective and radiological outcome of 131 Scarf osteotomies (106 hallux valgus patients, mean age: 57.5 years, range: 22-90 years) were retrospectively analyzed. Mean follow-up was 22.4 months (range: 6 months-5 years). Surgical indications were: intermetatarsal angle (IMA) of 12-23°; increased proximal articular angle (PAA>8°), and range of motion of the metatarsophalangeal joint in flexion and extension >40°. Exclusion criteria were severe osteoporosis and/or osteoarthritis. The mean subjective range of motion (ROM) of the great toe post-surgery was 0.8±1.73 points (0: full ROM, 10: total stiffness). The mean subjective cosmetic result was 2.7±2.7 points (0: excellent, 10: poor). The overall post-operative patient satisfaction with the result was high (2.1±2.5 points (0: excellent, 10: poor). The mean hallux valgus angle improvement was 16.6° (pre-operative mean value: 37.5°) which was statistically significant (p<0.01). The IMA improved by an average of 5.96° from a pre-operative mean value of 15.4° (p<0.01). Neither osteonecrosis of the distal fragment nor perioperative fractures were noted during the follow-up. In keeping with our follow-up results, the Scarf osteotomy approach shows potential in the therapy of hallux valgus.

Evaluating nuclear protein-coding genes for phylogenetic utility in beetles.

Although nuclear protein-coding genes have proven broadly useful for phylogenetic inference, relatively few such genes are regularly employed in studies of Coleoptera, the most diverse insect order. We increase the number of loci available for beetle systematics by developing protocols for three genes previously unused in beetles (alpha-spectrin, RNA polymerase II and topoisomerase I) and by refining protocols for five genes already in use (arginine kinase, CAD, enolase, PEPCK and wingless). We evaluate the phylogenetic performance of each gene in a Bayesian framework against a presumably known test phylogeny. The test phylogeny covers 31 beetle specimens and two outgroup taxa of varying age, including three of the four extant beetle suborders and a denser sampling in Adephaga and in the carabid genus Bembidion. All eight genes perform well for Cenozoic divergences and accurately separate closely related species within Bembidion, but individual genes differ markedly in accuracy over the older Mesozoic and Permian divergences. The concatenated data reconstruct the test phylogeny with high support in both Bayesian and parsimony analyses, indicating that combining data from multiple nuclear loci will be a fruitful approach for assembling the beetle tree of life.

Spinal deformity after multilevel osteoplastic laminotomy.

Multilevel laminectomy in children has a significant rate of postoperative spinal deformity. To decrease the incidence of this complication, the use of osteoplastic laminotomy is advocated to minimise the risk of spinal deformity by preserving the normal architecture of the spine. In this retrospective study, a 10-year series of a paediatric population undergoing multilevel osteoplastic laminotomy is reviewed to determine the incidence, especially in contrast to laminectomies, and to identify factors that affect the occurrence of spinal column deformity. Seventy patients (mean age 4.2 years) underwent multilevel osteoplastic laminotomy for congenital anomalies or removal of spinal tumours. All patients had a clinical and radiographic examination preoperatively, 12 months postoperatively and at follow-up. Mean follow-up was 5.3 years (range 3-12.6 years). Nineteen patients (27%) had a new or progressive spinal deformity. There was an increased incidence in patients who had surgery for spinal tumours (P<0.05), surgery of the cervical spine (<0.01), and who had more than five levels of the spine included (P<0.05). A review of the literature on children with multilevel laminectomy (n=330), the incidence of spinal deformity found a significantly higher (46%) compared to our study group. This study demonstrates that osteoplastic laminotomy was found to be very effective in decreasing the incidence of spinal deformities after spinal-canal surgery for spinal-cord tumours or congenital anomalies in children and adolescents. The choice of an anatomical reconstructive surgical technique such as osteoplastic laminotomy seems to be essential to minimise secondary problems due to the surgical technique itself. Nevertheless, growing patients should be followed up for several years after the initial operation for early detection and consequent management of any possible deformity of the spinal column.

How to prevent small stature in Rett syndrome-associated collapsing spine syndrome.

Severe scoliosis in Rett syndrome is an important orthopedic, neurologic, and pediatric problem. The curve in Rett syndrome is of a neurologic type, has its highest incidence during early childhood, and shows rapid progression. In this study, the authors report the results of a 4-year follow-up of a 10-year-old Rett syndrome female patient with early onset and severe rapid progressive thoracolumbar scoliosis. The first signs of spinal deformity were documented at age 3 years. During adolescence, the patient developed a 115-degree thoracolumbal scoliosis with reduced respiratory volume due to a collapsing spine syndrome. To stop this life-threatening progression of the curve, the patient was treated by a 2-stage surgical procedure. The combination of an anterior release, halo traction, and posterior instrumented fusion from Th3 to L5 using a computer-assisted technique was performed. An excellent reduction of the deformity was achieved (postoperative 24-degree Cobb angle). After 4 years, the authors found a radiologically solid spinal fusion and no progression of the deformity. Operative treatment regimes and etiology of severe spinal deformities in Rett syndrome were discussed. The high perioperative risks in Rett syndrome patients who underwent spinal surgery may be reduced by an early cooperation between orthopedic and pediatric specialists. When considering recent data from literature, it can be concluded that an early correction of spine deformities in Rett syndrome patients may prevent a life-threatening collapsing spine syndrome.

Remodeling of the spine in spondylodiscitis of children at the age of 3 years or younger.

Spondylitis/spondylodiscitis is still an uncommon diagnosis often with a delay in diagnosis and treatment due to the uncharacteristic symptoms. The aim of this study is to increase the awareness and outline a pattern of investigation and treatment. We present six children with an average age of 23 months (19-33 months) at time of diagnosis, conservative treated and with a mean follow-up of 31 months (12-65 months). The evaluation included past medical history, clinical symptoms, X-rays, MRI-investigations and laboratory studies [CRP, erythrocytes sedimentation rate (ESR), white blood count (WBC) and blood cultures] during the course of treatment and follow-up. The predominate clinical findings were: limp, refusal to walk and/or back pain. The mean duration of symptoms until presentation at our clinic was 24 days (4-42 days), the final diagnosis was set after an average of 12 days (7-14 days). Laboratory findings were unspecific but ESR best correlated with the clinical symptoms during the therapy. Five patients were treated by parenteral antibiotics for a minimum of 3 weeks, followed by oral antibiotics adapted to the clinical and laboratory findings. One child received a combined antituberculous chemotherapy after positive skin test for tbc. All six children were immobilized with a body-plaster-cast for an average time of 15 weeks (5-26 weeks). Four patients additionally were treated by further corset therapy for an average of 10 months (3-18 months). Radiological findings on plane X-rays (a.p. and lateral views) at time of diagnosis were decreased height of the disk space and erosions of adjacent vertebral endplates and residues of these radiological changes with signs of bony healing (sclerotic vertebral endplates or partial fusion) were seen at the latest follow-up. There was no case of instability or deformity like scoliosis or kyphosis. The MRI showed the earliest detectable typical vertebral bone involvements and confirmed the diagnosis in combination with laboratory findings and clinical symptoms. Spondylitis/spondylodiscitis should be considered as diagnosis in children with refusal to walk or gait disturbances especially in combination with elevated ESR. MRI is the tool of choice to set the diagnosis early. With an adequate and early therapy of bracing (body-plaster-cast), antibiotics and clinical monitoring good long-term result without spine instability or deformity can be achieved.

Pullout strength of anterior spinal instrumentation: a product comparison of seven screws in calf vertebral bodies.

A lot of new implant devices for spine surgery are coming onto the market, in which vertebral screws play a fundamental role. The new screws developed for surgery of spine deformities have to be compared to established systems. A biomechanical in vitro study was designed to assess the bone-screw interface fixation strength of seven different screws used for correction of scoliosis in spine surgery. The objectives of the current study were twofold: (1) to evaluate the initial strength at the bone-screw interface of newly developed vertebral screws (Universal Spine System II) compared to established systems (product comparison) and (2) to evaluate the influence of screw design, screw diameter, screw length and bone mineral density on pullout strength. Fifty-six calf vertebral bodies were instrumented with seven different screws (USS II anterior 8.0 mm, USS II posterior 6.2 mm, KASS 6.25 mm, USS II anterior 6.2 mm, USS II posterior 5.2 mm, USS 6.0 mm, USS 5.0 mm). Bone mineral density (BMD) was determined by quantitative computed tomography (QCT). Failure in axial pullout was tested using a displacement-controlled universal test machine. USS II anterior 8.0 mm showed higher pullout strength than all other screws. The difference constituted a tendency (P = 0.108) when compared to USS II posterior 6.2 mm (+19%) and was significant in comparison to the other screws (+30 to +55%, P < 0.002). USS II posterior 6.2 mm showed significantly higher pullout strength than USS 5.0 mm (+30%, P = 0.014). The other screws did not differ significantly in pullout strength. Pullout strength correlated significantly with BMD (P = 0.0015) and vertebral body width/screw length (P < 0.001). The newly developed screws for spine surgery (USS II) show higher pullout strength when compared to established systems. Screw design had no significant influence on pullout force in vertebral body screws, but outer diameter of the screw, screw length and BMD are good predictors of pullout resistance.

Niche differentiation and fine-scale projections for Argentine ants based on remotely sensed data.

Modeling ecological niches of species is a promising approach for predicting the geographic potential of invasive species in new environments. Argentine ants (Linepithema humile) rank among the most successful invasive species: native to South America, they have invaded broad areas worldwide. Despite their widespread success, little is known about what makes an area susceptible--or not--to invasion. Here, we use a genetic algorithm approach to ecological niche modeling based on high-resolution remote-sensing data to examine the roles of niche similarity and difference in predicting invasions by this species. Our comparisons support a picture of general conservatism of the species' ecological characteristics, in spite of distinct geographic and community contexts.