Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab

Background

Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity.

Patients and methods

Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel.

Results

A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A.

Conclusion

Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.

Recruitment of Labelled Monocytes by Experimental Venous Thrombi

Objective. Infusing monocytes that have been stimulated to produce fibrinolytic activators and factors that regulate cell proliferation, migration and maturation, might enhance venous thrombus resolution. The aim of this study was to determine the time course of infused monocyte recruitment into venous thrombus in an appropriate model of this disease. Design and Methods. Thrombus was induced in the inferior vena cava of male Wistar rats using reduced flow (80-90% stenosis). The vessel wall was examined at 1hr by scanning electron microscopy. Resolving thrombi with surrounding vena cava were obtained at 1, 7, 14 and 21 days after induction (n = 8). Sections, taken at 0.5 mm intervals (10-15 sections per thrombus), were stained using haematoxylin, Martius Scarlet Blue and antibodies against monocytes, platelets and fibrin. Sections from human venous thrombi (n = 4) were similarly stained. The area occupied by monocytes (in relative pixel units, RPU) was determined using computer aided image analysis. Peripheral rat blood monocytes were extracted, fluorescently labelled and injected intravenously into 7 rats prior to thrombus induction. Vena cava with thrombus was harvested 1 h, 2, 3, 4, 7, 14 and 25 days after induction and their fluorescence measured. The fluorescent content of the caval wall and thrombus was analysed in greater detail at 2 and 25 days after thrombus induction (n = 4 at each time interval). Results. Experimental thrombi were structurally similar to human thrombus and resolved within 14-21 days. Scanning electron microscopy showed minimal endothelial damage at 1 h with signs of early thrombus formation (platelet, red cell leukocyte and fibrin deposition). Neutrophils were the predominant leukocyte in the thrombus at 1 day, with monocytes making up only 0.3% (0.04% sem) of the area of the thrombus. There was a steady increase in thrombus monocyte content and by 21 days the percentage area of thrombus covered by monocytes had increased by over 35 fold to 11.5% (2.3% sem) (p <0.001). Initially, monocytes appeared around the edge of the thrombus and became more evenly distributed through the thrombus as resolution progressed. Labelled monocytes could be found in the circulation up to 1 week after infusion. The fluorescent content (RPU) of the thrombus increased over 25 days (mean RPU At 2 days 0.012, sem 0.005; mean RPU at 25 days 1.062, sem 0.252, p = 0.008). The number of labelled monocytes in the vessel wall peaked at 2 days and decreased thereafter.

Changes in the Levels of Soluble Adhesion Molecules and Coagulation Factors in Patients with Deep Vein Thrombosis

Current biochemical markers of thrombosis, such as d-dimer, are of little value in demonstrating the presence of thrombus postoperatively, as their levels are elevated by surgery. Thrombosis involves adhesive interactions between the endothelium, platelets and leukocytes. The aim of the study was to determine which of a panel of haemostatic and adhesion factors are altered by the presence of thrombus, but not by surgery. These factors were measured in 20 patients with established spontaneous DVTs, 13 patients having hip replacement surgery and 28 control patients. Circulating levels of P-selectin, VCAM-1 and tissue factor were found to be increased when thrombus was present (p <0.018, p <0.0001, p <0.0028 respectively), but were not altered by surgery. The significance of these circulating factors in venous thrombosis remains to be established, but it is conceivable that they are the product of increased leukocyte trafficking and activity. Assay of VCAM-1, in particular, may be of use in the early detection of venous thrombi in postoperative patients.

Inflammatory gastrointestinal diseases associated with PD-1 blockade antibodies

BACKGROUND

Immune check-point blockade agents have shown clinical activity in cancer patients but are associated with immune-related adverse events that could limit their development. The aim of this study was to describe the gastrointestinal immune-related adverse events (GI-irAE) in patients with cancer treated with anti-PD-1.

METHODS

this is a retrospective study of consecutive adult patients who had a suspected GI-irAE due to anti-PD-1 antibodies between 2013 and 2016. Patients were recruited through a pharmacovigilance registry. Patients' data were reviewed by a multidisciplinary committee that included gastroenterologists, oncologists and a pathologist. Quantitative variables are described by median (range), qualitative variable by frequency (percentage).

RESULTS

Forty-four patients were addressed to a Gastroenterology unit for a suspected GI-IrAE. Twenty patients had a confirmed GI-irAE related to anti-PD-1, which occurred 4.2 months (0.2; 22.1) after the initiation of anti-PD-1. GI-IrAE incidence rate under anti-PD-1 treatment was estimated to be 1.5%. Among patients with GI-IrAE, main symptoms were diarrhoea (n = 16, 80%), abdominal pain (n = 13, 65%), nausea and vomiting (n = 11, 55%), intestinal obstruction (n = 1, 5%), and haematochezia (n = 2, 10%). No patient had colectomy. Four distinct categories of GI-irAE were observed: acute colitis (n = 8, 40%), microscopic colitis (n = 7, 35%), upper gastrointestinal tract inflammation (n = 4, 20%) and pseudo-obstruction (n = 1, 5%). Response rates to corticosteroids were 87.5% (7/8) in acute colitis, 57% (4/7) in microscopic colitis and 75% (3/4) in upper gastrointestinal tract inflammation. Median time to resolution was 36 days (6-172) in acute colitis, and 98 days (42-226) in microscopic colitis.

CONCLUSION

This study suggests that GI-irAE are different and less frequent with anti PD-1 than with anti CTLA-4.

Validation of the "Security Needs Assessment Profile" for measuring the profiles of security needs of Chinese forensic psychiatric inpatients

Mapping forensic psychiatric services with the security needs of patients is a salient step in service planning, audit and review. A valid and reliable instrument for measuring the security needs of Chinese forensic psychiatric inpatients was not yet available. This study aimed to develop and validate the Chinese version of the Security Needs Assessment Profile for measuring the profiles of security needs of Chinese forensic psychiatric inpatients. The Security Needs Assessment Profile by Davis was translated into Chinese. Its face validity, content validity, construct validity and internal consistency reliability were assessed by measuring the security needs of 98 Chinese forensic psychiatric inpatients. Principal factor analysis for construct validity provided a six-factor security needs model explaining 68.7% of the variance. Based on the Cronbach's alpha coefficient, the internal consistency reliability was rated as acceptable for procedural security (0.73), and fair for both physical security (0.62) and relational security (0.58). A significant sex difference (p=0.002) in total security score was found. The Chinese version of the Security Needs Assessment Profile is a valid and reliable instrument for assessing the security needs of Chinese forensic psychiatric inpatients.

A new model for ancient DNA decay based on paleogenomic meta-analysis

The persistence of DNA over archaeological and paleontological timescales in diverse environments has led to a revolutionary body of paleogenomic research, yet the dynamics of DNA degradation are still poorly understood. We analyzed 185 paleogenomic datasets and compared DNA survival with environmental variables and sample ages. We find cytosine deamination follows a conventional thermal age model, but we find no correlation between DNA fragmentation and sample age over the timespans analyzed, even when controlling for environmental variables. We propose a model for ancient DNA decay wherein fragmentation rapidly reaches a threshold, then subsequently slows. The observed loss of DNA over time may be due to a bulk diffusion process in many cases, highlighting the importance of tissues and environments creating effectively closed systems for DNA preservation. This model of DNA degradation is largely based on mammal bone samples due to published genomic dataset availability. Continued refinement to the model to reflect diverse biological systems and tissue types will further improve our understanding of ancient DNA breakdown dynamics.

Students' perceptions of lecturing approaches: traditional versus interactive teaching

BACKGROUND

There is an increasing trend toward transcending from traditional teaching to student-centered methodologies that actively engage students. We aimed to analyze students' perceptions of effective interactive teaching using PollEverywhere Audience Response System (ARS) as a worthwhile teaching methodology. It can be of great help in maintaining students' attention and in facilitating the lecturer to pick up students' misunderstandings and correct them.

MATERIALS AND METHODS

This system was introduced to the undergraduate dental curriculum to increase student's motivation and attention, giving immediate feedback on student understanding during an anatomy module. Computer science (CS) students who were more familiar with the use of this technology were also involved in the study for comparison and validation of the findings. The lecturer strategically inserted questions using PollEverywhere ARS. Students' perception of the effective interactive teaching using this technology was evaluated statistically using a questionnaire and focus groups.

RESULTS

It promoted interactivity, focused attention, and provided feedback on comprehension. A total of 95% reported that it increased their participation and found that it clarified their thinking and helped to focus on key points. Another 81.7% mentioned that it increased their motivation to learn. Students regarded it as a useful method for giving real-time feedback, which stimulated their performance and participation. Data from CS students echoed the findings from the dental students. Reports from focus groups demonstrated that this strategy was helpful in focusing students' attention and in clarifying information.

DISCUSSION

PollEverywhere encouraged all students to participate during the learning process. This has proven to be an effective tool for improving students' understanding and critical thinking.

CONCLUSION

Students regarded PollEverywhere as an effective teaching innovation that encouraged deeper ongoing retention of information. It was found to be an effective teaching aid in monitoring students' progress and identifying deficiencies. This is of benefit in a module where interactivity is considered important.

Fat mass and obesity associated (FTO) gene influences skeletal muscle phenotypes in non-resistance trained males and elite rugby playing position

Background

FTO gene variants have been associated with obesity phenotypes in sedentary and obese populations, but rarely with skeletal muscle and elite athlete phenotypes.

Methods

In 1089 participants, comprising 530 elite rugby athletes and 559 non-athletes, DNA was collected and genotyped for the FTO rs9939609 variant using real-time PCR. In a subgroup of non-resistance trained individuals (NT; n = 120), we also assessed structural and functional skeletal muscle phenotypes using dual energy x-ray absorptiometry, ultrasound and isokinetic dynamometry. In a subgroup of rugby athletes (n = 77), we assessed muscle power during a countermovement jump.

Results

In NT, TT genotype and T allele carriers had greater total body (4.8% and 4.1%) and total appendicular lean mass (LM; 3.0% and 2.1%) compared to AA genotype, with greater arm LM (0.8%) in T allele carriers and leg LM (2.1%) for TT, compared to AA genotype. Furthermore, the T allele was more common (94%) in selected elite rugby union athletes (back three and centre players) who are most reliant on LM rather than total body mass for success, compared to other rugby athletes (82%; P = 0.01, OR = 3.34) and controls (84%; P = 0.03, OR = 2.88). Accordingly, these athletes had greater peak power relative to body mass than other rugby athletes (14%; P = 2 x 10^-6).

Conclusion

Collectively, these results suggest that the T allele is associated with increased LM and elite athletic success. This has implications for athletic populations, as well as conditions characterised by low LM such as sarcopenia and cachexia.

Barcoding the largest animals on Earth: ongoing challenges and molecular solutions in the taxonomic identification of ancient cetaceans

Over the last few centuries, many cetacean species have witnessed dramatic global declines due to industrial overharvesting and other anthropogenic influences, and thus are key targets for conservation. Whale bones recovered from archaeological and palaeontological contexts can provide essential baseline information on the past geographical distribution and abundance of species required for developing informed conservation policies. Here we review the challenges with identifying whale bones through traditional anatomical methods, as well as the opportunities provided by new molecular analyses. Through a case study focused on the North Sea, we demonstrate how the utility of this (pre)historic data is currently limited by a lack of accurate taxonomic information for the majority of ancient cetacean remains. We then discuss current opportunities presented by molecular identification methods such as DNA barcoding and collagen peptide mass fingerprinting (zooarchaeology by mass spectrometry), and highlight the importance of molecular identifications in assessing ancient species' distributions through a case study focused on the Mediterranean. We conclude by considering high-throughput molecular approaches such as hybridization capture followed by next-generation sequencing as cost-effective approaches for enhancing the ecological informativeness of these ancient sample sets.This article is part of the themed issue 'From DNA barcodes to biomes'.

The MMP3 gene in musculoskeletal soft tissue injury risk profiling: A study in two independent sample groups

Matrix metalloproteinase-3 (MMP3) is a mediator of matrix remodelling and a proposed susceptibility locus in the genetic profile of musculoskeletal soft tissue injuries. Therefore, this study aimed to validate the MMP3 gene as a risk marker for these injuries by conducting a case control genetic association study in two independent samples groups. Three previously investigated MMP3 variants (rs679620, rs591058 and rs650108) in addition to the functional promoter variant (rs3025058) were genotyped in 195 Australian control participants and 79 Australian individuals with chronic Achilles tendinopathy. Similarly, 234 South African individuals with acute anterior cruciate ligament ruptures and 232 matched control participants were also analysed. Based on high linkage with the previously associated MMP3 variant rs679620, rs3025058 was inferred and found to be associated with increased risk for Achilles tendinopathy within the South African group (P = 0.012; OR: 2.88; 95% CI: 1.4 to 6.1). Lastly, the 6A-G-C-G haplotype, constructed from the investigated variants, was significantly associated with reduced risk for Achilles tendinopathy (29% CON vs. 20% TEN, P = 0.037) in the Australian group. In conclusion, a signal surrounding MMP3 is apparent with respect to Achilles tendinopathy. However, whether the investigated variants are contributing to injury susceptibility or whether they are merely linked to the risk conferring variants mapping elsewhere within the MMP gene cluster on chromosome 11, still requires refining.

Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves

The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( < 0.05) in the HEAD/HEART group (45.08 ± 0.72) than the CONTROL group (47.10 ± 0.72). There were no differences ( > 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( < 0.05) than that from the HEAD/HEART group (6,656.4 ± 143.5 g). Overall, the data indicated no difference between the CONTROL and HEAD/HEART groups with regard to animal welfare because the initial stun was effective in all calves. However, longissimus thoracis L* and blood yield were negatively impacted by the HEAD/HEART method. The data in this study suggest that secondary induction of cardiac arrest is not necessary with effective nonpenetrating captive bolt stunning in veal calves.

Association of ACTN3 R577X but not ACE I/D gene variants with elite rugby union player status and playing position

We aimed to quantify the ACE I/D and ACTN3 R577X (rs1815739) genetic variants in elite rugby athletes (rugby union and league) and compare genotype frequencies to controls and between playing positions. The rugby athlete cohort consisted of 507 Caucasian men, including 431 rugby union athletes that for some analyses were divided into backs and forwards and into specific positional groups: front five, back row, half backs, centers, and back three. Controls were 710 Caucasian men and women. Real-time PCR of genomic DNA was used to determine genotypes using TaqMan probes and groups were compared using χ² and odds ratio (OR) statistics. Correction of P values for multiple comparisons was according to Benjamini-Hochberg. There was no difference in ACE I/D genotype between groups. ACTN3 XX genotype tended to be underrepresented in rugby union backs (15.7%) compared with forwards (24.8%, P = 0.06). Interestingly, the 69 back three players (wings and full backs) in rugby union included only six XX genotype individuals (8.7%), with the R allele more common in the back three (68.8%) than controls (58.0%; χ² = 6.672, P = 0.04; OR = 1.60) and forwards (47.5%; χ² = 11.768, P = 0.01; OR = 2.00). Association of ACTN3 R577X with playing position in elite rugby union athletes suggests inherited fatigue resistance is more prevalent in forwards, while inherited sprint ability is more prevalent in backs, especially wings and full backs. These results also demonstrate the advantage of focusing genetic studies on a large cohort within a single sport, especially when intrasport positional differences exist, instead of combining several sports with varied demands and athlete characteristics.

Management of immune checkpoint blockade dysimmune toxicities: a collaborative position paper

Monoclonal antibodies targeted against the immune checkpoint molecules CTLA-4 and PD-1 have recently obtained approval for the treatment of metastatic melanoma and advanced/refractory non small-cell lung cancers. Therefore, their use will not be limited anymore to selected hospitals involved in clinical trials. Indeed, they will be routinely prescribed in many cancer centers across the world. Besides their efficacy profile, these immune targeted agents also generate immune-related adverse events (irAEs). This new family of dysimmune toxicities remains largely unknown to the broad oncology community. Although severe irAEs remain rare (∼10% of cases under monotherapy), they can become life-threatening if not anticipated and managed appropriately. Over the last 5 years, Gustave Roussy has accumulated a significant experience in the prescription of immune checkpoint blockade (ICB) antibodies and the management of their toxicities. Together with the collaboration of Gustave Roussy's network of organ specialists with expertise in irAEs, we propose here some practical guidelines for the oncologist to help in the clinical care of patients under ICB immunotherapy.

High-dose chemotherapy with autologous stem cell transplantation in relapsed or refractory germ cell tumours: outcomes and prognostic variables in a case series of 17 patients

BACKGROUND

Optimal therapy for men relapsing after initial chemotherapy for germ cell tumours (GCT) is poorly defined. Both conventional dose salvage regimens and high-dose chemotherapy with autologous stem cell transplantation (HDCT-ASCT) have been utilised.

AIMS

To examine patients who received HDCT-ASCT for relapsed GCT within a single Australian centre.

METHODS

Records between 2000 and 2012 were analysed for baseline characteristics, treatment-related toxicity and survival. Prognosis at the time of HDCT-ASCT was classified according to the International Prognostic Factors Study Group (IPFSG).

RESULTS

Seventeen patients received HDCT-ASCT, median age 34 (21-46), with 41% having primary refractory disease and 53% with high/very high risk disease by IPFSG. The most common regimen utilised was paclitaxel/ifosfamide followed by high-dose carboplatin/etoposide (TI-CE; n = 12). The median duration of grade 4 (G4) neutropenia was 11 days (range 9-17) with febrile neutropenia in 90% resulting in four intensive care unit admissions (8%). Median duration of G4 thrombocytopenia was 10 days (range 8-19) requiring a median of two pooled platelets bags (range 0-33) per episode. Transplant-related mortality occurred in one patient (veno-occlusive disease). Twenty-seven per cent of HDCT-ASCT cycles were associated with grade 3 mucositis (median total parenteral nutrition days = 5 (0-23)). Two-year progression-free survival (PFS) and overall survival (OS) rates were 59% and 71%. Patients who received HDCT-ASCT as second or subsequent relapse fared worse than those treated with HDCT-ASCT at first relapse (hazard ratio 0.23 (95% confidence interval: 0.04, 1.37; P-value 0.09). Three-year OS for those who received TI-CE at first relapse was 90%.

CONCLUSIONS

HDCT-ASCT for relapsed GCT is effective with acceptable toxicity. There was encouraging PFS/OS, particularly in a poor-prognosis cohort.