Preoperative assessment of skeletal muscle mass during magnetic resonance enterography in patients with Crohn's disease.

Measurement of the psoas muscle area has been applied to estimate lean muscle mass as a surrogate marker of sarcopenia, but there is a paucity of evidence regarding the influence of sarcopenia on clinical outcomes following inflammatory bowel disease surgery. The aim of this study was to evaluate the association between MRI enterography defined sarcopenia and postoperative complications in patients undergoing elective ileocaecal resection for Crohn's disease. To obtain cross sectional area measurement of the psoas muscle, the freehand area tool was used to trace the margin of each psoas muscle at the level of L4, with the sum recorded as Total Psoas Area (TPA). The total cross sectional muscle area of the abdominal wall was recorded as Skeletal Muscle Area (SMA), while myosteatosis was measured by normalising the psoas muscle intensity with the mean intensity of the cerebrospinal fluid. The primary outcome was the incidence of 30-day postoperative complications in patients in the lowest quartile of TPA and SMA. 31 patients were included and ten patients (32.25%) developed postoperative complications within 30 days of surgery. The cut-off values for the lowest quartile for TPA were 11.93 cm2 in men and 9.77 cm2 in women, including a total of 8 patients (25.8%) with 5 patients in this group (62.5%) developing postoperative complications and 3 patients (37.5%) Clavien-Dindo class ≥ 3 complications. The cut-off values for the lowest quartile for SMA were 73.49 cm2 in men and 65.85 cm2 in women, with 4 patients out of 8 (50%) developing postoperative complications. Psoas muscle cross sectional area and skeletal mass area can be estimated on Magnetic Resonance Enterography as surrogate markers of sarcopenia with high inter-observer agreement.

Laboratory Approach to the Diagnosis of Culture-Negative Infective Endocarditis.

Blood-culture negative endocarditis (BCNE) accounts for up to 35% of all cases of infective endocarditis (IE) and is a serious life-threatening condition with considerable morbidity and mortality. Rapid detection and identification of the causative pathogen is essential for timely, directed therapy. Blood-culture negative endocarditis presents a diagnostic and therapeutic challenge. Causes of BCNE are varied including: treatment with antibiotic agents prior to blood culture collection; sub-optimal specimen collection; and/or infection due to fastidious (eg. nutritionally variant streptococci), intracellular (eg. Coxiella burnetii, Bartonella species) or non-culturable or difficult to culture organisms (eg. Mycobacteria, Tropheryma whipplei and fungi); as well as non-infective aetiologies. Here, we review aetiological and diagnostic approaches to BCNE including newer molecular based techniques, with a brief summary of imaging investigation and treatment principles.

Increased prevalence of influenza B/Victoria lineage viruses during early stages of the 2015 influenza season in New South Wales, Australia: implications for vaccination and planning.

During the early weeks of the 2015 Australian influenza season, influenza B accounted for 67% (821/1,234) of all positive influenza tests in New South Wales. Of 81 successive influenza B viruses characterised, 33 (41%) were from children aged < 16 years; 23/81 (28%) belonged to the B/Victoria lineage. This lineage is not contained in the southern hemisphere's 2015 trivalent influenza vaccine. The significant B/Victoria lineage activity in the southern hemisphere suggests that the quadrivalent vaccine should be considered for the northern hemisphere.

Risk stratification and outcome of cellulitis admitted to hospital.

OBJECTIVES: To identify risk factors associated with mortality and adverse outcome of community acquired cellulitis/erysipelas requiring hospital admission. METHODS: A retrospective analysis of 395 episodes of cellulitis/erysipelas admitted to a tertiary referral hospital between January 1999 and December 2006. RESULTS: Mortality was 2.5% (10/395). There were 112 complications (28.4%). Median hospitalisation was 5 days. Factors independently associated with mortality, adverse outcome and prolonged stay (>7 days) were bacteraemia and albumin <30 g/L. A risk stratification model was designed based on factors independently associated with adverse outcome: altered mental status, neutrophilia/paenia, discharge from the cellulitic area, hypoalbuminaemia and history of congestive cardiac failure. Adverse outcome risk among patients with scores <4, 6-9 and >9 was <20%, 55% and 100%, respectively. All patients who died had admission score >or=4. Factors independently associated with prolonged hospitalisation were: age >60, symptom duration >4 days, hypoalbuminaemia, bacteraemia, isolation of MRSA and time to effective antibiotics >8 h. MRSA was more frequent among patients admitted during 2003-2006 (OR 2.43, 95% CI: 1-12-5.27). Streptococci accounted for most bacteraemia (11/20). Infectious Disease physician input was independently associated with shorter hospitalisation. CONCLUSIONS: Cellulitis/erysipelas requiring hospitalisation confers considerable morbidity and mortality. Clinical markers present on admission can be used to stratify patient risk of mortality and adverse outcome.

MRSA detection: comparison of two molecular methods (BD GeneOhm PCR assay and Easy-Plex) with two selective MRSA agars (MRSA-ID and Oxoid MRSA) for nasal swabs.

Screening of patients is an important component for methicillin-resistant Staphylococcus aureus (MRSA) containment. The aim of this study was to determine the utility of molecular methods compared to selective agars for MRSA detection. Consecutive high risk patients (n = 200) were screened for nasal MRSA colonization using chromogenic selective agars (MRSA ID and CMRSA) as well as the BD GeneOhm MRSA (previously known as IDI-MRSA) and the Easy-Plex commercial real time PCR assays. The sensitivities of the molecular methods were similar to the BD GeneOhm MRSA (86%) and Easy-Plex (84%). The chromogenic agars, MRSA ID and CMRSA, showed sensitivities of 62% and 84%, respectively. Sensitivity was influenced by both the MRSA antibiograms and MRSA clonal type. The specificity was >98% in all methods except for the Easy-Plex assay (90%). Sensitivity of selective agars increased with 48 hours of incubation with a corresponding decrease in specificity. In conclusion, molecular detection methods for MRSA remain sensitive and rapid but are associated with greater expense.

Immunocontraception with zona pellucida proteins.

The prospect of an immunological approach to contraception that would disrupt the process of fertilisation itself has resulted in a considerable interest into research in this area. It has been known for some time that antibodies raised against the zona pellucida (ZP) can suppress fertility very effectively. However, the initial optimism of this approach has been marred by the appearance of an ovarian pathology characterised by disruption of folliculogenesis and depletion of the primordial follicle pool. Adverse auto-immune reactions have been observed in the ovaries of mice after the induction of immunity with mouse ZP3 epitopes. However, this was associated with lymphocytic infiltration of the ovarian stroma, which could be circumvented by careful selection of B-cell epitopes to induce reversible infertility. In order to identify similar epitopes on primate ZP3, epitope-mapping studies were performed and incorporated into chimeric vaccines that included a promiscuous T-helper cell epitope. Both single and triple peptide vaccines have been evaluated in vivo and no detrimental effects on ovarian function were observed. The resulting high titre antibodies bound exclusively to the ZP of marmoset and human ovarian sections and could suppress in vitro human sperm-egg binding by approximately 60%, but did not prevent pregnancy in actively immunised female marmosets. Thus, considerable research is still required to identify a combination of ZP3 epitopes that will induce infertility free of any unwanted side effects.

Design and evaluation of a ZP3 peptide vaccine in a homologous primate model.

The concept of a safe, immunocontraceptive vaccine using the zona pellucida glycoprotein 3 (ZP3) as an immunogen has been marred by the appearance of ovarian dysfunction in several species. However, careful selection of epitopes on mouse ZP3 have demonstrated that it is possible to segregate contraceptive bone marrow-derived (B)-cell epitopes from the cytotoxic thymus-derived (T)-cell epitopes thought to be responsible for inducing ovarian disease. B-cell epitopes on marmoset ZP3 (mstZP3) were identified by epitope mapping studies. Using a panel of polyclonal antibodies against recombinant mstZP3, an immunodominant epitope mstZP3(301-320) was identified. A chimeric peptide was co-linearly synthesized incorporating this sequence with a promiscuous tetanus toxoid T-helper cell epitope. Using the common marmoset (Callithrix jacchus) as an animal model, we have compared the consequences of active immunization with homologous recombinant mstZP3 and mstZP3(301-320) chimeric peptide vaccine. Long-term infertility was achieved using mstZP3 but at the expense of ovarian function. In contrast, no disruption to ovarian function was observed following mstZP3(301-320) immunization. Antibodies to this peptide immunolocalized to the zona pellucida of both marmoset and human ovarian sections and inhibited human sperm-zona binding by approximately 60% in vitro. However, in-vivo studies indicated that targeting a single ZP3 epitope was insufficient to reliably and consistently achieve a contraceptive effect.

Relative impact of oxidative stress on the functional competence and genomic integrity of human spermatozoa.

Reactive oxygen metabolites are known to disrupt sperm-oocyte fusion, sperm movement, and DNA integrity; however, the relative sensitivities of these elements to oxidative stress are unknown. In this study these factors were assessed in human spermatozoa exposed to increasing levels of oxidative stress achieved through the stimulation of endogenous oxidant generation with NADPH or direct exposure to hydrogen peroxide. At low levels of oxidative stress, DNA fragmentation was significantly reduced while the rates of sperm-oocyte fusion were significantly enhanced. As the level of oxidative stress increased, the spermatozoa exhibited significantly elevated levels of DNA damage (p < 0.001) and yet continued to express an enhanced capacity for sperm-oocyte fusion. At the highest levels of oxidative stress, extremely high rates of DNA fragmentation were observed but the spermatozoa exhibited a parallel loss in their capacities for movement and oocyte fusion. These studies emphasize how redox mechanisms can either enhance or disrupt the functional and genomic integrity of human spermatozoa depending on the intensity of the oxidative stimulus. Because these qualities are affected at different rates, spermatozoa exhibiting significant DNA damage are still capable of fertilizing the oocyte. These results may have long-term implications for the safety of assisted conception procedures in cases associated with oxidative stress.