Risk factors associated with high linezolid trough plasma concentrations

AIM

The major concern of linezolid is the adverse events. High linezolid trough serum concentration (Cmin) has been associated with toxicity. The aim of this study was to analyze factors associated with high Cmin.

METHODS

Main clinical characteristics of 104 patients treated with 600 mg/12 hours of linezolid were retrospectively reviewed. Samples were obtained just before the next dose after at least three doses and within the first 8 days of treatment. High Cmin was considered when it was >8 mg/L. Univariate and multivariate analysis were performed.

RESULTS

34.6% patients had a Cmin >8 mg/L, and they were older and had more frequently an estimated glomerular filtration by MDRD <40 mL/min. There were more patients co-treated with rifampin in the group with low Cmin. The only factor independently associated with Cmin >8 was the renal function. Patients with an eGF < 40 mL/min had significantly higher Cmin than those with eGF > 80 mL/min (OR: 4.273) and there was a trend towards a high Cmin in patients with eGF between 40-80 mL/min (OR: 2.109).

CONCLUSIONS

High Cmin were frequent, especially in patients with MDRD <40 mL/min. Therapeutic drug monitoring could be useful to avoid toxicity in patients with renal dysfunction.

BRG1/SMARCA4 is essential for neuroblastoma cell viability through modulation of cell death and survival pathways

Neuroblastoma (NB) is a neoplasm of the sympathetic nervous system, and is the most common solid tumor of infancy. NBs are very heterogeneous, with a clinical course ranging from spontaneous regression to resistance to all current forms of treatment. High-risk patients need intense chemotherapy, and only 30-40% will be cured. Relapsed or metastatic tumors acquire multi-drug resistance, raising the need for alternative treatments. Owing to the diverse mechanisms that are responsible of NB chemoresistance, we aimed to target epigenetic factors that control multiple pathways to bypass therapy resistance. We found that the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4/BRG1) was consistently upregulated in advanced stages of NB, with high BRG1 levels being indicative of poor outcome. Loss-of-function experiments in vitro and in vivo showed that BRG1 is essential for the proliferation of NB cells. Furthermore, whole-genome transcriptome analysis revealed that BRG1 controls the expression of key elements of oncogenic pathways such as PI3K/AKT and BCL2, which offers a promising new combination therapy for high-risk NB.

Staphylococcus aureus bacteremic pneumonia

Staphylococcus aureus bacteremic pneumonia is an uncommon cause of hospitalization, with a high mortality rate. However, published reports are scarce and have included a small number of cases. All patients with S. aureus bacteremic pneumonia were prospectively collected in our institution from 2000 to 2014, and a retrospective revision was performed to identify risk factors associated with methicillin resistance and to update the mortality of this entity. A total of 98 patients were admitted: 57.1 % were due to methicillin-susceptible S. aureus (MSSA) and 42.8 % due to methicillin-resistant S. aureus (MRSA). In 40 patients (40.8 %), the infection was community acquired. Thirteen were ventilator-associated pneumonia episodes. The most frequent comorbidities were chronic lung disease (34.7 %), chronic renal failure (31.6 %), diabetes mellitus (29.6 %), and cardiovascular disease (31.6 %). Septic shock was present in 46 patients (46.9 %). The 30-day mortality was 46.9 %. MRSA infections occurred in older patients, more frequently with cardiovascular diseases, and they had received antibiotic treatment in the previous month more often than MSSA-infected patients. Patients with infection due to MSSA presented more frequently with septic shock, but they received more frequently appropriate empirical antibiotic therapy than patients with MRSA pneumonia (96 % vs. 38.1 %), and no differences in mortality were observed between both groups. In conclusion, S. aureus bacteremic pneumonia is a severe infection that, nowadays, affects people with comorbidities and the mortality is still high.

Influence of evisceration time and carcass ageing conditions on wild venison quality. Preliminary study

The influence of common carcass preparation practices of wild red deer on the physicochemical, microbiological and sensory quality of venison was assessed by varying evisceration time and ageing method. Deer were head shot; half were eviscerated 30 min and the other half 4 h post mortem. In both groups (n=18), 6 carcasses were skinned immediately after evisceration and aged for 24 h; 6 were aged unskinned for 24 h and 6 were aged unskinned for 72 h at 10°C. Ageing method had a significant effect on the sensory quality of venison loin; unskinned ageing was associated with an increase of odour and taste intensity, and higher scores for gamey and sweet/caramel flavours. Carcasses aged for 72 h displayed darker and tender meat, but increased aerobic bacterial counts. Evisceration time had less influence on loin quality, although off-flavours were more often detected in deer eviscerated 4h post mortem.

Risk factors of hepatocellular carcinoma recurrence after liver transplantation: accuracy of the alpha-fetoprotein model in a single-center experience

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) and cirrhosis after a liver transplantation (LT) is a major concern, and a strict Milan criteria selection of candidates does not accurately discriminate the relapse rate after LT.

PURPOSE

This study sought to analyze the risk factors affecting tumor recurrence after LT for related cirrhosis HCC and the application of the French prognostic model (preLT alpha-fetoprotein [AFP], size, number) in a single center.

METHODS

In a retrospective observational study of LT for HCC and cirrhosis, clinicopathological features were analyzed. Also, the preoperative and postoperative AFP model score was calculated with a cutoff of 2.

RESULTS

Of 480, 109 patients underwent cadaveric LT for HCC. Eight of them had a relapse (7%). High AFP level, AFP model score >2, high pathological tumor-node-metastasis (pTNM) stage, poor differentiation, macrovascular-microvascular invasion, infiltration, and R1 margin were statistically significant (P < .05) for recurrence. Also, in the preoperative model, AFP score >2 was a predictor of worse survival (1-, 3-, 5-, 10-year survival of 81%, 51%, 30%, 30% vs 90%, 76%, 73%, 69% in ≤2, with P = .005). Regarding the postoperative model, similar results were found (1-, 3-, 5-, 10-year survival of 84%, 47%, 37%, 37% vs 90%, 78%, 73%, 52%, P = .028) between AFP model score >2 and ≤2, respectively. However, Milan and up-to-7 criteria were not accurate in recurrence nor in survival.

CONCLUSIONS

The French AFP model has proven to be a more discerning prognostic tool than other established criteria in the prediction of recurrence and survival. Also, in postoperative prognosis, pathological risk factors for relapse such as pTNM, differentiation grade, macrovascular-microvascular invasion, infiltration, and R1 margin have been predictors of recurrence.

Severe ASIA syndrome associated with lymph node, thoracic, and pulmonary silicone infiltration following breast implant rupture: experience with four cases

Silicone has been considered biologically inert; thus it has been employed in many medical devices and nowadays is commonly used in plastic surgery for mammary prosthesis. It is well tolerated in most cases. However, autoimmune disorders and siliconomas with granulomatous reactions after silicone implant rupture have been described. We report cases of four women who developed systemic disorders following rupture of silicone breast implants resulting in lymph node and thoracic silicone infiltration. The symptoms in these cases, including arthralgia, myalgia, generalized weakness, severe fatigue, sleeping disturbances, cognitive impairment, memory loss, irritable bowel syndrome, and weight loss, clearly match the criteria of the recently defined autoimmune/inflammatory syndrome induced by adjuvants (ASIA).

[Screening with angiographic images prior to (99m)Tc-HMPAO labelled leukocyte scintigraphy in the diagnosis of periprosthetic infection]

AIM

To evaluate the impact of the angioscintigrapy of the three phase bone scan as screening method to rule out infection of the hip and knee prosthesis prior to performing the (99m)Tc-HMPAO leukocyte scintigraphy.

MATERIAL AND METHODS

A total of 120 (70 women, 50 men; mean age 71±11years) with clinical suspicion of hip (n=63) or knee (n=57) infection of the prosthesis and clinical suspicion of infection were evaluated prospectively. All patients underwent three-phase bone scan (angioscintigraphy, vascular and bone phase) and (99m)Tc-HMPAO-labelled white blood cell scintigraphy. Final diagnosis of infection was made by microbiological documentation or clinical follow-up for at least 12months.

RESULTS

Eighteen out of 120 patients were diagnosed of infection of hip prosthesis (n=10) or knee prosthesis (n=8). The angioscintigraphy was positive in 15/18 infected cases and in 21/102 of the non-infected cases with a sensitivity of 83%, specificity of 79% and negative predictive value of 97%. Sensitivity and specificity of (99m)Tc-HMPAO leukocyte scintigraphy were 72% and 95%, respectively. If the leukocyte labeled scintigraphies had been used exclusively for patients with positive angioscintigraphy, this would have saved up to 70% of the (99m)Tc-HMPAO leukocyte scintigraphies performed. There were no cases of infection with positive labeled leukocyte scintigraphy and negative angioscintigraphy.

CONCLUSION

Angioscintigraphy (blood flow phase of bone scan) is a useful technique for screening for hip and knee joint prosthesis infection, significantly reducing the need for (99m)Tc-HMPAO leukocyte scintigraphy without affecting the sensitivity of the technique.

Efficient photovoltaic and electroluminescent perovskite devices

Planar diode structures employing hybrid organic–inorganic methylammonium lead iodide perovskites lead to multifunctional devices exhibiting both a high photovoltaic efficiency and good electroluminescence.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study

The objective of this study was to review the characteristics and outcome of prosthetic joint infections (PJI) due to Enterococcus sp. collected in 18 hospitals from six European countries. Patients with a PJI due to Enterococcus sp. diagnosed between January 1999 and July 2012 were retrospectively reviewed. Relevant information about demographics, comorbidity, clinical characteristics, microbiological data, surgical treatment and outcome was registered. Univariable and multivariable analyses were performed. A total of 203 patients met the inclusion criteria. The mean (SD) was 70.4 (13.6) years. In 59 patients the infection was diagnosed within the first 30 days (29.1%) from arthroplasty, in 44 (21.7%) between 31 and 90 days, in 54 (26.6%) between 91 days and 2 years and in 43 (21%) after 2 years. Enterococcus faecalis was isolated in 176 cases (89%). In 107 (54%) patients the infection was polymicrobial. Any comorbidity (OR 2.53, 95% CI 1.18-5.40, p 0.01), and fever (OR 2.65, 95% CI 1.23-5.69, p 0.01) were independently associated with failure. The only factor associated with remission was infections diagnosed later than 2 years (OR 0.25, 95% CI 0.09-0.71, p 0.009). In conclusion, prosthetic joint infections due to Enterococcus sp. were diagnosed within the first 2 years from arthroplasty in >70% of the patients, almost 50% had at least one comorbidity and infections were frequently polymicrobial (54%). The global failure rate was 44% and patients with comorbidities, fever, and diagnosed within the first 2 years from arthroplasty had a poor prognosis.

MYCN repression of Lifeguard/FAIM2 enhances neuroblastoma aggressiveness

Neuroblastoma (NBL) is the most common solid tumor in infants and accounts for 15% of all pediatric cancer deaths. Several risk factors predict NBL outcome: age at the time of diagnosis, stage, chromosome alterations and MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-Derived Homolog) amplification, which characterizes the subset of the most aggressive NBLs with an overall survival below 30%. MYCN-amplified tumors develop exceptional chemoresistance and metastatic capacity. These properties have been linked to defects in the apoptotic machinery, either by silencing components of the extrinsic apoptotic pathway (e.g. caspase-8) or by overexpression of antiapoptotic regulators (e.g. Bcl-2, Mcl-1 or FLIP). Very little is known on the implication of death receptors and their antagonists in NBL. In this work, the expression levels of several death receptor antagonists were analyzed in multiple human NBL data sets. We report that Lifeguard (LFG/FAIM2 (Fas apoptosis inhibitory molecule 2)/NMP35) is downregulated in the most aggressive and undifferentiated tumors. Intringuingly, although LFG has been initially characterized as an antiapoptotic protein, we have found a new association with NBL differentiation. Moreover, LFG repression resulted in reduced cell adhesion, increased sphere growth and enhanced migration, thus conferring a higher metastatic capacity to NBL cells. Furthermore, LFG expression was found to be directly repressed by MYCN at the transcriptional level. Our data, which support a new functional role for a hitherto undiscovered MYCN target, provide a new link between MYCN overexpression and increased NBL metastatic properties.

Treatment options for methicillin-resistant Staphylococcus aureus (MRSA) infection: Where are we now?

Methicillin-resistant Staphylococcus aureus (MRSA) infection continues to be a substantial global problem with significant associated morbidity and mortality. This review summarises the discussions that took place at the 4th MRSA Consensus Conference in relation to the current treatment options for serious MRSA infections and how to optimise whichever therapy is embarked upon. It highlights the many challenges faced by both the laboratory and clinicians in the diagnosis and treatment of MRSA infections.

Clinical and microbiological findings in prosthetic joint replacement due to aseptic loosening

OBJECTIVES

A role for microorganisms in aseptic prosthetic loosening (AL) is postulated. We analyse the microbiological and clinical findings of patients with suspected AL, and compare them with patients with chronic prosthetic joint infection (PJI).

METHODS

Prospective study (2011-2012) of patients with presumed AL. Evaluation of tissue samples (≥5; TS) at the time of surgery and sonication fluid (SF) of prosthesis.

RESULTS

According to positive culture in TS/SF, 89 patients were divided into: Group1: (≥2 positive-TS; n = 12); Group2: single positive-TS and concordant SF (n = 10); Group3: one positive or non-concordant TS or SF (n = 38); and Group4: cultures negative (n = 29). Positive-SF was always concordant with TS in Group 1 (75%); it was positive in 74% in Group 3. Median months (prosthesis-age: implantation to revision arthroplasty) for PJI and Group 1-4 was 21, 46, 65, 63 and 81, respectively (P < 0.001); they also had a different dynamic trend in prosthesis failure (P < 0.001).

CONCLUSIONS

Several patients with suspected AL are misdiagnosed PJI. Results from SF correlated well with TS in Group 1, led us to consider single positive-TS as significant (Group 2) and to suggest that microorganisms were on the prosthesis (Group 3). We observed a correlation between microbiology and prosthesis-age, which supports that early loosening is more often caused by hidden PJI than late loosening.

Comparison of bacterial results from conventional cultures of the periprosthetic membrane and the synovial or pseudocapsule during hip revision arthroplasty

INTRODUCTION

Bacterial identification is essential to diagnose and treat a revision for prosthetic loosening of an infected hip. The purpose of this study was to determine whether conventional cultures from the periprosthetic membrane are superior to synovial/pseudocapsule samples in the diagnosis of infection in hip revision arthroplasty.

MATERIALS AND METHODS

We performed a prospective study including all hip revisions from October 2009 to October of 2011. Once the implants were removed and prior to the administration of the antibiotic prophylaxis, six periprosthetic samples from different sites were sent to the laboratory for culturing: two periprosthetic fluid samples, two solid material (synovial/pseudocapsule) samples and two swabs. Once the six samples were taken, antibiotic prophylaxis was administered and just as the implant was removed, two more solid samples of the periprosthetic membrane were obtained.

RESULTS

Of a total of 86 hip revision surgeries, 22 were considered septic revisions postoperatively, of which 16 resulted in positive cultures. Of these 16 revisions, 14 obtained the same microbiologic diagnostic when considering either the synovial/pseudocapsule culture results or the solid membrane sample.

CONCLUSIONS

We conclude that the membrane sample for a conventional culture is not superior to the synovial/pseudocapsule sample in detecting microorganisms.

Effect of partial replacement of pork meat with an olive oil organogel on the physicochemical and sensory quality of dry-ripened venison sausages

A venison salchichon was made using varying proportions of olive oil to replace the traditional pork meat and to obtain a healthier product. Six types of salchichon were produced. The control type contained 75% lean venison and 25% pork meat; in the other types, 15%, 25%, 35%, 45% and 55% of the pork meat were replaced by olive oil introduced in the form of an organogel (olive oil emulsified with soy protein and water). All types were satisfactory in terms of physicochemical characteristics (pH, a(w), moisture loss) and instrumental colour throughout ripening, and displayed acceptable levels of lipolysis (acidity index) and lipid oxidation (TBARS). Higher proportions of olive oil prompted an increase in monounsaturated fatty acid content (mainly C18:1). All six types of salchichon were judged acceptable by consumers, the highest scores being given to those in which no more than 25% of the pork meat was replaced by olive oil.