In silico MS/MS prediction for peptidoglycan profiling uncovers novel anti-inflammatory peptidoglycan fragments of the gut microbiota.

Peptidoglycan is an essential exoskeletal polymer across all bacteria. Gut microbiota-derived peptidoglycan fragments (PGNs) are increasingly recognized as key effector molecules that impact host biology. However, the current peptidoglycan analysis workflow relies on laborious manual identification from tandem mass spectrometry (MS/MS) data, impeding the discovery of novel bioactive PGNs in the gut microbiota. In this work, we built a computational tool PGN_MS2 that reliably simulates MS/MS spectra of PGNs and integrated it into the user-defined MS library of in silico PGN search space, facilitating automated PGN identification. Empowered by PGN_MS2, we comprehensively profiled gut bacterial peptidoglycan composition. Strikingly, the probiotic Bifidobacterium spp. manifests an abundant amount of the 1,6-anhydro-MurNAc moiety that is distinct from Gram-positive bacteria. In addition to biochemical characterization of three putative lytic transglycosylases (LTs) that are responsible for anhydro-PGN production in Bifidobacterium, we established that these 1,6-anhydro-PGNs exhibit potent anti-inflammatory activity in vitro, offering novel insights into Bifidobacterium-derived PGNs as molecular signals in gut microbiota-host crosstalk.

Management Paradigm of Central Nervous System Metastases in NSCLC: An Australian Perspective.

Life-prolonging central nervous system active systemic therapies for metastatic NSCLC have increased the complexity of managing brain metastases (BMs). Australian medical oncologists, radiation oncologists, and neurosurgeons discussed the evidence guiding the diverse clinical approaches to the management of BM in NSCLC. The Australian context is broadly applicable to other jurisdictions; therefore, we have documented these discussions as principles with broader applications. Patient management was stratified according to clinical and radiologic factors under two broad classifications of newly diagnosed BMs: symptomatic and asymptomatic. Other important considerations include the number and location of metastases, tumor histotypes, molecular subtype, and treatment purpose. Careful consideration of the pace and burden of symptoms, risk of worsening neurologic function at a short interval, and extracranial disease burden should determine whether central nervous system active systemic therapies are used alone or in combination with local therapies (surgery with or without radiation therapy). Most clinical trial evidence currently focuses on historical treatment options or a single treatment modality rather than the optimal sequencing of multiple modern therapies; therefore, an individualized approach is key in a rapidly changing therapeutic landscape.

Molecular Docking Reveals Critical Residues in Candida albicans Cyr1 for Peptidoglycan Recognition and Hyphal Growth.

The key virulent characteristic of Candida albicans, the major fungal pathogen in humans, lies in its ability to switch between the benign yeast state and the invasive hyphal form upon exposure to specific stimuli. Among the numerous hyphal-inducing signals, bacterial peptidoglycan fragments (PGNs) represent the most potent inducers of C. albicans hyphal growth. The sole adenylyl cyclase Cyr1 in C. albicans is a known sensor for PGNs and activates downstream signaling of hyphal growth, yet the molecular details of PGN-Cyr1 interactions have remained unclear. In this study, we performed in silico docking of a PGN motif to the modeled structure of the Cyr1 leucine-rich repeat (LRR) domain and uncovered four putative PGN-interacting residues in Cyr1_LRR. The critical roles of these residues in PGN binding and supporting C. albicans hyphal growth were demonstrated by in-gel fluorescence binding assay and hyphal induction assay, respectively. Remarkably, the C. albicans mutant harboring the cyr1 variant allele that is defective for PGN recognition exhibits significantly reduced cytotoxicity in macrophage infection assay. Overall, our work offered important insights into the molecular recognition of PGNs by C. albicans Cyr1 sensor protein, establishing that disruption of PGN recognition by Cyr1 results in defective hyphal growth and reduced virulence of C. albicans. Our findings provide an exciting starting point for the future development of Cyr1 antagonists as novel anti-virulence therapeutics to combat C. albicans invasive growth and infection.

An initial Glasgow Coma Scale score of 8 or less does not define severe brain injury.

The wide-spread use of an initial 'Glasgow Coma Scale (GCS) 8 or less' to define and dichotomise 'severe' from 'mild' or 'moderate' traumatic brain injury (TBI) is an out-dated research heuristic that has become an epidemiological convenience transfixing clinical care. Triaging based on GCS can delay the care of patients who have rapidly evolving injuries. Sole reliance on the initial GCS can therefore provide a false sense of security to caregivers and fail to provide timely care for patients presenting with GCS greater than 8. Nearly 50 years after the development of the GCS - and the resultant misplaced clinical and statistical definitions - TBI remains a heterogeneous entity, in which 'best practice' and 'prognoses' are poorly stratified by GCS alone. There is an urgent need for a paradigm shift towards more effective initial assessment of TBI.

2D kV orthogonal imaging with fiducial markers is more precise for daily image guided alignments than soft-tissue cone beam computed tomography for prostate radiation therapy.

PURPOSE: The hypothesis is that 2-dimensional kV orthogonal imaging with fiducial markers (kV-FM) and soft-tissue cone beam computed tomography (ST-CBCT) are equally reproducible for daily positional alignments for image guided (IG) intensity modulated radiation therapy (IMRT) for prostate cancer. METHODS AND MATERIALS: Ten patients undergoing definitive treatment for prostate cancer with IG-IMRT were imaged daily with kV-FM and ST-CBCT. For each acquired kV and CBCT image, offline alignments to the digitally reconstructed radiograph or planning CT, respectively, were made twice by the same physician to assess intraobserver test-retest reproducibility. The 256 kV and 142 CBCT images were analyzed, and the test-retest analysis was performed again on a subset of images by another physician to verify the results. RESULTS: The results demonstrated that kV-FM had better intraobserver test-retest reproducibility in the anterior-posterior (AP; 95% confidence interval [CI] Pearson correlation coefficient [r], 0.987-0.991), left-right (LR; 95% CI r, 0.955-0.969), and superior-inferior (SI; 95% CI r, 0.971-0.980) directions for daily IG alignments compared with ST-CBCT (AP: 95% CI r, 0.804-0.877; LR: 95% CI r, 0.877-0.924; SI: 95% CI r, 0.791-0.869). Errors associated with intraobserver test-retest reproducibility were submillimeter with kV-FM (AP: 0.4 ± 0.7 mm; RL: 0.4 ± 1.0 mm; SI: 0.5 ± 0.7 mm) compared with ST-CBCT (AP: 2.1 ± 2.2 mm; LR: 1.3 ± 1.4 mm; SI: 1.2 ± 1.8 mm). The mean shift differences between kV-FM and ST-CBCT were 0.3 ± 3.8 mm for AP, -1.1 ± 8.5 mm for LR, and -2.0 ± 3.7 mm for SI. Dose-volume histograms were generated and showed that test-retest variability associated with ST-CBCT IG-alignments resulted in significantly increased dose to normal structures and a reduced planning target volume dose in many patients. CONCLUSIONS: The kV-FM-based daily IG alignment for IMRT of prostate cancer is more precise than ST-CBCT, as assessed by a physician's ability to reproducibly align images. Given the magnitude of the error introduced by inconsistency in making ST-CBCT alignments, these data support a role for daily kV imaging of FM to enhance the precision of external beam dose delivery to the prostate.

The influence of testosterone suppression and recovery on sexual function in men with prostate cancer: observations from a prospective study in men undergoing intermittent androgen suppression.

PURPOSE: We investigated the effects of testosterone change on the sexual function of men with prostate cancer undergoing intermittent maximal androgen deprivation therapy. MATERIALS AND METHODS: We conducted a phase II cohort study of 250 patients with prostate cancer undergoing intermittent maximal androgen deprivation therapy. Flutamide (Eulexin®) 250 mg 3 times daily and leuprolide (Lucrin®) 22.5 mg were given during a 9-month treatment phase (ONPhase). Therapy was ceased provided that prostate specific antigen was 4 ng/ml or less. Monitoring continued every 3 months for a further 2 years (OFFPhase) unless re-treatment occurred. Sexual function was assessed with the QLQ-PR25 version 3.0 prostate module in conjunction with the QLQ-C30 questionnaire at baseline and every 3 months thereafter. RESULTS: At baseline 46% of patients reported sexual activity with almost half (43%) reporting mild or no erectile problems. Of the men 63% reported an interest in sex (libido), with 28% reporting moderate to high libido. In addition, 26% felt less masculine as a result of illness or treatment. By 3 months of ONPhase all parameters deteriorated, worsening to a low at 9 months. Only 13% of the men reported sexual activity and 10% reported moderate to high libido. The proportion of men feeling less masculine increased to 50%. During the OFFPhase recovery was observed. Of those previously sexually active men 52% resumed sexual activity. Of these patients all reported erectile function returning to baseline. Levels of libido, masculinity and sexual activity recovered but not to baseline levels. CONCLUSIONS: Libido, sexual activity and perceptions of masculinity deteriorate during ONPhase. Of the sexually active men at baseline half will resume sexual activity despite 9 months of androgen deprivation therapy.

Outcomes from combined chemoradiotherapy in unresectable and locally advanced resected cholangiocarcinoma.

PURPOSE: Whilst surgery is the only potentially curative treatment for cholangiocarcinoma, many patients are either unfit for major surgery or have unresectable disease. Patients who undergo attempted curative resective surgery often have involved resection margins. The role of radiotherapy in these settings has not been clarified and is often not considered because of fears of late complications, especially liver and gastrointestinal toxicity. We present our experience of treating cholangiocarcinoma, either unresectable or locally advanced, with conformal radiotherapy and concurrent chemotherapy, examining survival, toxicity, patterns of failure and details of radiotherapy and chemotherapy administered. METHODS: Between 1995 and 2005, 20 patients, median age 60.5 years (range 45-78 years) with cholangiocarcinoma received radical conformal radiotherapy (median dose 46 Gy in 1.8-2.0 Gy fractions) with concurrent cisplatin/5-FU and sequential gemcitabine chemotherapy. RESULTS: Overall median survival was 20.4 months, 2 year survival, 43% and relapse-free survival, 9.6 months. 19/20 patients (95%) have died. One patient remains alive with liver and bone metastases. First site of failure was local and within radiotherapy field in 9/20 (45%) patients. No patient required interruption of radiotherapy for radiation toxicity, and none experienced subsequent late liver toxicity. CONCLUSIONS: The survival of this group of historically poor prognosis patients is encouraging. Durable local control was achieved in a majority of patients having chemoradiotherapy and toxicity was not severe. Although most patients still succumbed to disease, treatment delayed onset of progression. Conformal radiotherapy should be considered as an integral component in new investigative approaches to treatment in this rare cancer.