Use of dithiothreitol to improve the diagnosis of prosthetic joint infections

Diagnosis of prosthetic joint infections (PJIs) remains a challenge for microbiologists, despite new techniques for bacteria isolation have been developed in recent years. A widely recognized standard method has not yet been indicated mainly because of limitations due difficult procedures and need of dedicated instrumentation. We evaluated the ability of a sulfhydryl compound routinely used in microbiology laboratories, dithiothreitol (DTT), to dislodge bacteria from biofilm, keeping them alive and cultivable for identification and antibiotic susceptibility testing. We compared DTT treatment against sonication of prosthesis and culture of periprosthetic tissues, in order to establish if it could be introduced in routine microbiological diagnosis of PJIs. The study was conducted on 76 patients, 34 with aseptic loosening of their prosthesis and 42 who were diagnosed for PJI. DTT treatment gave results similar to sonication in terms of bacterial yielding. Sonication provided higher sensitivity (71.4%) and specificity (94.1%) respect to periprosthetic tissue culture, while DTT showed the same specificity of sonication but a better sensitivity (85.7%), especially when the causative microorganism was Staphylococcus epidermidis. In conclusion, we demonstrated that DTT could be used for PJIs diagnosis, thanks to its ease of use and its high sensitivity and specificity. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1694–1699, 2013     

Risk stratification by injury distribution in polytrauma patients – does the clavicular fracture play a role?

Background

Thoracic and extremity injuries are common in polytraumatized patients. The clavicle limits the upper thoracic cage and connects the body and upper extremities. It is easy to examine and is visible on standard emergency room radiographs. We hypothesize that clavicular fracture in polytrauma patients indicates the presence of further injuries of the upper extremities, head, neck and thorax.

Material and methods

Retrospective study including patients admitted between 2008 and 2012 to a level-I trauma center. Inclusion criteria: ISS?>?16, two or more injured body regions, clavicular fracture. Control group: patients admitted in 2011, ISS?>?16, two or more injured body regions, no clavicular fracture. Patient information was obtained from the patients’ charts; evaluation of radiographic findings was performed; scoring was based on the Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS) AIS/ISS; data were analyzed using Pearson’s correlation and the Mann–Whitney U-test in SPSS (version 11.5.1); graphs were drawn using EXCEL®.

Results

Thirty-four patients with clavicular fracture (C+) and 40 without (C-) were included; the mean ISS was 25 (range 16–57), m?=?70%, f?=?30%; age 43.3 years (range 9–88); clavicular fractures were positively correlated with severe thoracic (p?=?0.011, OR 4.5: KI 1.3–15.3), external (p?<?0.001, OR 9.2: KI 2.7–30.9) and upper extremity injuries (p?<?0.001, OR 33.2: KI 6.9–16.04 resp. p?=?0.004, OR 12.5: KI 1.5–102.9). C?+?showed a lower head/neck AIS (p?=?0.033), higher thorax AIS (p?=?0.04), arm/shoulder AIS (p?=?0.001) and external AIS (0.003) than C-. Mean hospital stay and ICU treatment time were longer in the C?+?group (p?=?0.001 and p?=?0.025 respectively).

Conclusion

A clavicular fracture can be diagnosed easily and may be used as a pointer for further thoracic and upper extremity injuries in polytrauma patients that might have been otherwise missed. Special attention should be paid on second and tertiary survey.

     

Targeted Next-generation Sequencing of Advanced Prostate Cancer Identifies Potential Therapeutic Targets and Disease Heterogeneity

Background

Most personalized cancer care strategies involving DNA sequencing are highly reliant on acquiring sufficient fresh or frozen tissue. It has been challenging to comprehensively evaluate the genome of advanced prostate cancer (PCa) because of limited access to metastatic tissue.

Objective

To demonstrate the feasibility of a novel next-generation sequencing (NGS)–based platform that can be used with archival formalin-fixed paraffin-embedded (FFPE) biopsy tissue to evaluate the spectrum of DNA alterations seen in advanced PCa.

Design, setting, and participants

FFPE samples (including archival prostatectomies and prostate needle biopsies) were obtained from 45 patients representing the spectrum of disease: localized PCa, metastatic hormone-naive PCa, and metastatic castration-resistant PCa (CRPC). We also assessed paired primaries and metastases to understand disease heterogeneity and disease progression.

Intervention

At least 50 ng of tumor DNA was extracted from FFPE samples and used for hybridization capture and NGS using the Illumina HiSeq 2000 platform.

Outcome measurements and statistical analysis

A total of 3320 exons of 182 cancer-associated genes and 37 introns of 14 commonly rearranged genes were evaluated for genomic alterations.

Results and limitations

We obtained an average sequencing depth of >900X. Overall, 44% of CRPCs harbored genomic alterations involving the androgen receptor gene (AR), including AR copy number gain (24% of CRPCs) or AR point mutation (20% of CRPCs). Other recurrent mutations included transmembrane protease, serine 2 gene (TMPRSS2):v-ets erythroblastosis virus E26 oncogene homolog (avian) gene (ERG) fusion (44%); phosphatase and tensin homolog gene (PTEN) loss (44%); tumor protein p53 gene (TP53) mutation (40%); retinoblastoma gene (RB) loss (28%); v-myc myelocytomatosis viral oncogene homolog (avian) gene (MYC) gain (12%); and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α gene (PIK3CA) mutation (4%). There was a high incidence of genomic alterations involving key genes important for DNA repair, including breast cancer 2, early onset gene (BRCA2) loss (12%) and ataxia telangiectasia mutated gene (ATM) mutations (8%); these alterations are potentially targetable with poly(adenosine diphosphate-ribose)polymerase inhibitors. A novel and actionable rearrangement involving the v-raf murine sarcoma viral oncogene homolog B1 gene (BRAF) was also detected.

Conclusions

This first-in-principle study demonstrates the feasibility of performing in-depth DNA analyses using FFPE tissue and brings new insight toward understanding the genomic landscape within advanced PCa.     

Bone mineral density measurements performed by cone-beam computed tomography in the bisphosphonate-related osteonecrosis-affected jaw

Objectives

The aims of this study were to determine the bone mineral density (BMD) in bisphosphonate-related osteonecrosis of the jaw (BRONJ) by cone-beam computed tomography (CBCT) measurements and to correlate these measurements with the current stages recommended by the American Association of Oral and Maxillofacial Surgeons (AAOMS).

Methods

Bone mineral density measurements of various areas in 24 bisphosphonate-related osteonecrosis (BRON) jaws were evaluated by CBCT. Another 24 age- and sex-matched patients without any bone pathologies served as the control group. Data acquisition was highly standardized to ensure maximum reliability in the comparisons of BMD measurements by CBCT.

Results

Compared with the control group, the bisphosphonate patients had significantly higher (p????0.01) BMDs in the non-affected jaw areas ipsilateral and contralateral to the BRON within the maxilla and mandible. The highest BMDs within the BRON jaws were observed in the BRON-adjacent areas relative to the non-affected ipsilateral and contralateral areas. Regarding the correlation with the AAOMS stages, the BMDs of the evaluated areas of BRONJ showed no significant differences (p????0.05) between the stages.

Conclusions

Bisphosphonate-related bone pathologies can be detected by CBCT and are associated with increased BMDs, not only in clinically obvious BRONJ areas, but also in clinically unapparent areas, suggesting a subclinical general osteosclerosis of the jaw. The data transferability to other CBCT devices needs to be further elucidated and compared with multislice CT.     

Continuous electrocardiographic monitoring during automobile driving. Studies in normal subjects and patients with coronary disease

The electrocardiogram was continuously recorded during a two and a half hour period of driving in 65 normal subjects and in 66 subjects with documented coronary heart disease.

In normal subjects, except for a variable increase in heart rate, no significant changes were observed.

Among the subjects with coronary heart disease, significant electrocardiographic changes, i.e., ischemic type of S-T depression, multifocal premature contractions, ventricular bigeminal or trigeminal rhythm, were observed in 16.7 per cent. These changes occurred under relatively favorable driving conditions. The relation of such changes to the occurrence of accidents on the highway merits further study. The magnitude of this problem is indicated by the large number of subjects with coronary heart disease who drive.     

Interleukin-10 modulates the sensitivity of peritoneal B lymphocytes to chemokines with opposite effects on stromal cell-derived factor-1 and B-lymphocyte chemoattractant.

Interleukin-10 (IL-10) is constitutively produced by peritoneal B1a lymphocytes, and stromal cell-derived factor-1 (SDF-1) by mesothelial cells. Independent studies have shown that both IL-10 and SDF-1 are involved in the persistence of the peritoneal B-lymphocyte compartment. This study shows that IL-10 and SDF-1 act in synergy on peritoneal B lymphocytes. Indeed, autocrine production of IL-10 was absolutely required for all effects of SDF-1 on these cells, including increased proliferation, survival, and chemotaxis. Moreover, adding IL-10 to peritoneal B lymphocytes increased the effects of SDF-1. Neither IL-5, IL-6, nor IL-9 affected the response of peritoneal B lymphocytes to SDF-1. IL-10 was chemokinetic for peritoneal B lymphocytes, increasing their random mobility. It also potentiated the SDF-1-induced reorganization of the cytoskeleton without affecting CXCR4 gene expression by peritoneal B lymphocytes. Despite its chemokinetic properties, IL-10 abolished the migration of peritoneal B lymphocytes in response to B-lymphocyte chemoattractant (BLC), a chemokine targeting B lymphocytes to lymphoid organ follicles. The ability of B1a lymphocytes to produce IL-10 constitutively, combined with the opposite effects of this cytokine on the responses to SDF-1 and BLC, may account for the selective accumulation of B1 lymphocytes in body cavities.     

Inner retinal abnormalities in X-linked retinitis pigmentosa with RPGR mutations

PURPOSE: To investigate in vivo the retinal microstructure in X-linked retinitis pigmentosa (XLRP) caused by RPGR mutations as a prelude to treatment initiatives for this common form of RP. METHODS: Patients with RPGR-XLRP (n = 12; age range, 10-56 years) were studied by optical coherence tomography (OCT) in a wide region of central retina. Overall retinal thickness and outer nuclear layer (ONL) and inner retinal parameters across horizontal and vertical meridians were analyzed and compared. RESULTS: Retinal architecture of all patients with RPGR mutations was abnormal. At the fovea in younger patients, the ONL could be normal; but, at increasing eccentricities, there was a loss of photoreceptor laminar structure, even at the youngest ages studied. At later ages and advanced disease stages, the ONL was thin and reduced in extent. Inner retinal thickness, in contrast, was normal or hyperthick. Inner retinal thickening was detectable at all ages studied and was strongly associated with ONL loss. CONCLUSIONS: Inner retinal laminar abnormalities in RPGR-XLRP are likely to reflect a neuronal-glial retinal remodeling response to photoreceptor loss and are detectable relatively early in the disease course. These results should be factored into emerging therapeutic strategies for this form of RP.     

Reduced frequencies and suppressive function of CD4+CD25hi regulatory T cells in patients with chronic lymphocytic leukemia after therapy with fludarabine

Globally suppressed T-cell function has been described in many patients with cancer to be a major hurdle for the development of clinically efficient cancer immunotherapy. Inhibition of antitumor immune responses has been mainly linked to inhibitory factors present in cancer patients. More recently, increased frequencies of CD4+CD25hi regulatory T cells (Treg cells) have been described as an additional mechanism reducing immunity. We assessed 73 patients with B-cell chronic lymphocytic leukemia (CLL) and 42 healthy controls and demonstrated significantly increased frequencies of cytotoxic T lymphocyte-associated protein 4 (CTLA4+)-, Forkhead box P3 (FOXP3+)-, glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR+)-, CD62L+-, transforming growth factor beta1 (TGF-beta1+)-, interleukin 10 (IL-10+)-Treg cells in patients with CLL, with highest frequencies in untreated or progressing patients presenting with extended disease. Most surprisingly, in the majority of patients with CLL treated with fludarabine-containing therapy regimens the inhibitory function of Treg cells was decreased or even abrogated. In addition, frequencies of Treg cells were significantly decreased after therapy with fludarabine. In light of similar findings for cyclophosphamide the combination of fludarabine and cyclophosphamide might be further exploited in strategies reducing immunosuppression prior to cancer immunotherapy.     

An unusual interatrial septum

The images focus on a very rare atrial septal anatomy known as "double atrial septum with persistent interatrial space.” Only scarce reports of this anomaly are found in literature. Due to increasing use of catheter-based interventions requiring a transseptal puncture, the recognition of this anomaly is essential for performing safe and effective procedures.