The role of a small posterior malleolar fragment in trimalleolar fractures

Aims

The aim of this study was to investigate the effect of a posterior malleolar fragment (PMF), with < 25% ankle joint surface, on pressure distribution and joint-stability. There is still little scientific evidence available to advise on the size of PMF, which is essential to provide treatment. To date, studies show inconsistent results and recommendations for surgical treatment date from 1940.

Materials and Methods

A total of 12 cadaveric ankles were assigned to two study groups. A trimalleolar fracture was created, followed by open reduction and internal fixation. PMF was fixed in Group I, but not in Group II. Intra-articular pressure was measured and cyclic loading was performed.

Results

Contact area decreased following each fracture, while anatomical fixation restored it nearly to its intact level. Contact pressure decreased significantly with fixation of the PMF. In plantarflexion, the centre of force shifted significantly posteriorly in Group II and anteriorly in Group I. Load to failure testing showed no difference between the groups.

Conclusion

Surgical reduction of a small PMF with less than 25% ankle joint surface improves pressure distribution but does not affect ankle joint stability. Cite this article: Bone Joint J 2018;100-B:95–100.

Evidenzbasierte Medizin – Grundlagen und Anwendung in der Phlebologie

Die evidenzbasierte Medizin (EBM) ist zur internationalen Bewegung geworden, die Medizinern weltweit die zu einem Indikationsbereich bestehenden Erkenntnisse nutzbar machen will. Für die Behandlung wird der bestmögliche Grad angestrebt. Hierzu werden weltweit relevante Arbeiten in medizinischen Datenbanken erfasst und themenbezogen einer Gegenüberstellung und Analyse (systematic review) unterzogen. Im Ergebnis wird für ein Therapieverfahren oder ein Arzneimittel resümiert, unter welchen Umständen und aufgrund welcher Datenlage eine Wirksamkeit besteht.

Um die »Verlässlichkeit« von Studienergebnissen einzuschätzen, wurde ein System eingeführt, das Metaanalysen am höchsten und das Expertenurteil am geringsten bewertet. Zusammenstellung und systematische Bewertung werden von der Cochrane Collaboration geleistet, die national und international organisiert ist. Sie koordiniert die ärztliche Weiterbildung zum Thema EBM, erfasst und dokumentiert Systematic Reviews in der Cochrane Library.

Für die praktische Medizin wird EBM relevant, wenn wichtige therapeutische Felder mit systematischen Reviews analysiert wurden. Doch für große Teile der Medizin liegen keine ausreichenden Studien vor oder die publizierten Daten unterliegen einem so genannten Bias, z.B. durch Selektionseffekte bei der Patientenauswahl oder durch Nicht-Publikation negativer Ergebnisse. Die Grenzen und Möglichkeiten der EBM sollten bekannt sein, um die bereits geleistete Arbeit in der Praxis sinnvoll nutzen zu können.

Asymptomatic Clostridium difficile carriage rate post-fecal microbiota transplant is low: a prospective clinical and stool assessment

OBJECTIVES

We aimed to assess the asymptomatic Clostridium difficile carriage rates following fecal microbiota transplantation (FMT).

METHODS

All patients who underwent FMT for recurrent Clostridium difficile infection (CDI) via colonoscopy or sigmoidoscopy between June 2013 and April 2015 and had a minimum of 8-week follow-up post FMT at two tertiary care referral centres were included in the study. Patients were prospectively followed both clinically and with stool assessments for 8 weeks post FMT. Assessments occurred at 1 week and 4 weeks post FMT to assess for failure. Failure was defined as presence of diarrhoeal symptoms and a positive CDI stool test by polymerase chain reaction for toxin gene (PCR) at any time point during the 8-week follow-up period. CDI stool testing using PCR was performed at weeks 1 and 4 post FMT in asymptomatic patients as well.

RESULTS

167 patients were included. Twenty-eight patients (16.7% (28/167)) were FMT failures throughout the 8-week period. At week 1, seven patients had already failed the FMT. Of the remaining 160 patients, 144 were asymptomatic, and among these, 141 were negative for C. difficile toxin gene by PCR. This resulted in an asymptomatic carriage rate of 2.1% (3/144). At week 4, 143 patients had not yet failed FMT. Of these patients 129 patients were asymptomatic and among those, 125 were negative by PCR, resulting in an asymptomatic carriage rate of 3% (3/129).

CONCLUSIONS

Asymptomatic carriage after FMT is rare. This suggests that testing for cure after FMT in asymptomatic patients is not necessary.

Intensive Care in a Patient with Toxic Epidermal Necrolysis

Toxic epidermal necrolysis (TEN) is a serious adverse drug reaction with high lethality, which usually requires intensive-medical care. A 44-year-old man developed generalized exanthema with increasing exfoliation and mucosal involvement after taking allopurinol, ibuprofen, and etoricoxib. The clinical diagnosis of TEN was histologically confirmed. Prednisolone therapy with 3 mg/kg body weight (BW) was not able to prevent further progress to finally 80% of the body surface, and infliximab 5 mg/kg BW was given as a single dose. This prevented further progression of the TEN. Despite marked improvement in skin findings, the ICU stay was prolonged by a complex analgosedation, transient kidney failure, volume management, positioning therapy, and vegetatively impeded weaning. Moreover, there was colonization with multiresistant bacteria (MRSA and VRE). Nonetheless, the patient could be restored to health and was released after four weeks. Infliximab seems to be effective in the treatment of TEN, especially in cases of rapid progression. Moreover, patients with TEN are difficult to handle in intensive-medical care, whereby attention should especially be paid to sufficient pain therapy, and the positioning of the patient is a particular challenge.

Leishmaniasis auf Mallorca: Vorstellung eines ungewöhnlichen Verlaufs unter Immunsuppression

Das spanische Festland und die Balearen sind Endemiegebiete für die kutane und viszerale Leishmaniasis durch Leishmania infantum. Die kutane Leishmaniasis ist die häufigste Verlaufsform.

Der Hauptvektor, die Sandmücke Phlebotomus perniciosus, ist im gesamten Inselgebiet von Mallorca zu finden. Die Leishmaniasis zeichnet sich durch eine Vielzahl von klinischen Erscheinungsbildern aus. Der Immunstatus des Patienten spielt hierbei eine relevante Rolle für den Verlauf der Erkrankung und das Ansprechen der Therapie.

Census and evaluation of p53 target genes

The tumor suppressor p53 functions primarily as a transcription factor. Mutation of the TP53 gene alters its response pathway, and is central to the development of many cancers. The discovery of a large number of p53 target genes, which confer p53's tumor suppressor function, has led to increasingly complex models of p53 function. Recent meta-analysis approaches, however, are simplifying our understanding of how p53 functions as a transcription factor. In the survey presented here, a total set of 3661 direct p53 target genes is identified that comprise 3509 potential targets from 13 high-throughput studies, and 346 target genes from individual gene analyses. Comparison of the p53 target genes reported in individual studies with those identified in 13 high-throughput studies reveals limited consistency. Here, p53 target genes have been evaluated based on the meta-analysis data, and the results show that high-confidence p53 target genes are involved in multiple cellular responses, including cell cycle arrest, DNA repair, apoptosis, metabolism, autophagy, mRNA translation and feedback mechanisms. However, many p53 target genes are identified only in a small number of studies and have a higher likelihood of being false positives. While numerous mechanisms have been proposed for mediating gene regulation in response to p53, recent advances in our understanding of p53 function show that p53 itself is solely an activator of transcription, and gene downregulation by p53 is indirect and requires p21. Taking into account the function of p53 as an activator of transcription, recent results point to an unsophisticated means of regulation.

Particle damage sources for fused silica optics and their mitigation on high energy laser systems

High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of damage to critical fused silica optics, which grows rapidly upon exposure to additional laser pulses. Much progress has been made in eliminating damage precursors in as-processed fused silica optics (the advanced mitigation process, AMP3), and very high damage resistance has been demonstrated in laboratory studies. However, the full potential of these improvements has not yet been realized in actual laser systems. In this work, we explore the importance of additional damage sources-in particular, particle contamination-for fused silica optics fielded in a high-performance laser environment, the National Ignition Facility (NIF) laser system. We demonstrate that the most dangerous sources of particle contamination in a system-level environment are laser-driven particle sources. In the specific case of the NIF laser, we have identified the two important particle sources which account for nearly all the damage observed on AMP3 optics during full laser operation and present mitigations for these particle sources. Finally, with the elimination of these laser-driven particle sources, we demonstrate essentially damage free operation of AMP3 fused silica for ten large optics (a total of 12,000 cm² of beam area) for shots from 8.6 J/cm² to 9.5 J/cm² of 351 nm light (3 ns Gaussian pulse shapes). Potentially many other pulsed high energy laser systems have similar particle sources, and given the insight provided by this study, their identification and elimination should be possible. The mitigations demonstrated here are currently being employed for all large UV silica optics on the National Ignition Facility.