Nocardia infections in hematopoietic cell transplant recipients: a multicenter international retrospective study of the Infectious Diseases Working Party (IDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

BACKGROUND

Nocardiosis is rare after hematopoietic cell transplantation (HCT). Little is known regarding its presentation, management, and outcome in this population.

METHODS

In this retrospective international study, we reviewed nocardiosis episodes in HCT recipients (01.01.2000-31.12.2018; 135 transplant centers; 33 countries) and described their clinical, microbiological, radiological, and outcome characteristics.

RESULTS

We identified 81 nocardiosis episodes in 74 allo- and 7 auto-HCT recipients. Nocardiosis occurred at a median of 8 (IQR 4-18) months post-HCT. The most frequently involved organs were lungs (70/81; 86%) and brain (30/81; 37%); 29 (36%) patients were afebrile; 46/81 (57%) had disseminated infections. The most common lung imaging findings were consolidations (33/68; 49%) or nodules (32/68; 47%); and brain imaging findings were multiple brain abscesses (19/30; 63%). 10/30 (33%) patients with brain involvement lacked neurological symptoms. 14/48 (29%) patients were bacteremic. N. farcinica was the most common among molecularly identified species (27%, 12/44). Highest susceptibility rates were reported to linezolid 45/45 (100%), amikacin 56/57 (98%), trimethoprim-sulfamethoxazole 57/63 (90%), and imipenem 49/57 (86%).One-year and last follow-up (IQR: 4-42.5 months) all-cause mortality were 40% (32/81) and 52% (42/81), respectively. In the multivariable analysis, underlying disease not in complete remission (HR 2.81, 95%CI 1.32-5.95), and prior bacterial infection (HR 3.42, 95%CI 1.62-7.22) were associated with higher one-year all-cause mortality.

CONCLUSIONS

Nocardiosis is a late post-HCT infection usually manifesting as a pulmonary disease with frequent dissemination, brain infection and bacteremia. Brain imaging should be performed in HCT recipients with nocardiosis regardless of neurological symptoms. Overall mortality is high.

COVID-19 pandemic-a focused review for clinicians

BACKGROUND

The COVID-19 pandemic caused by SARS-CoV-2 remains a significant issue for global health, economics and society. A wealth of data has been generated since its emergence in December 2019, and it is vital for clinicians to keep up with this data from across the world at a time of uncertainty and constantly evolving guidelines and clinical practice.

OBJECTIVES

Here we provide an update for clinicians on the recent developments in the virology, diagnostics, clinical presentation, viral shedding, and treatment options for COVID-19 based on current literature.

SOURCES

We considered published peer-reviewed papers and non-peer-reviewed pre-print manuscripts on COVID19 and related aspects with an emphasis on clinical management aspects.

CONTENT

We describe the virological characteristics of SARS-CoV-2 and the clinical course of COVID-19 with an emphasis on diagnostic challenges, duration of viral shedding, severity markers and current treatment options.

IMPLICATIONS

The key challenge in managing COVID-19 remains patient density. However, accurate diagnosis as well as early identification and management of high-risk severe cases are important for many clinicians. For improved management of cases, there is a need to understand test probability of serology, qRT-PCR and radiological testing, and the efficacy of available treatment options that could be used in severe cases with a high risk of mortality.

Respiration resolved imaging with continuous stable state 2D acquisition using linear frequency SWEEP

Purpose

To investigate the potential of continuous radiofrequency (RF) shifting (SWEEP) as a technique for creating densely sampled data while maintaining a stable signal state for dynamic imaging.

Methods

We present a method where a continuous stable state of magnetization is swept smoothly across the anatomy of interest, creating an efficient approach to dense multiple 2D slice imaging. This is achieved by introducing a linear frequency offset to successive RF pulses shifting the excited slice by a fraction of the slice thickness with each successive repeat times (TR). Simulations and in vivo imaging were performed to assess how this affects the measured signal. Free breathing, respiration resolved 4D volumes in fetal/placental imaging is explored as potential application of this method.

Results

The SWEEP method maintained a stable signal state over a full acquisition reducing artifacts from unstable magnetization. Simulations demonstrated that the effects of SWEEP on slice profiles was of the same order as that produced by physiological motion observed with conventional methods. Respiration resolved 4D data acquired with this method shows reduced respiration artifacts and resilience to non‐rigid and non‐cyclic motion.

Conclusions

The SWEEP method is presented as a technique for improved acquisition efficiency of densely sampled short‐TR 2D sequences. Using conventional slice excitation the number of RF pulses required to enter a true steady state is excessively high when using short‐TR 2D acquisitions, SWEEP circumvents this limitation by creating a stable signal state that is preserved between slices.

Abstract P2-09-07: Preoperative pembrolizumab (Pembro) with radiation therapy (RT) in patients with operable triple-negative breast cancer (TNBC)

Background: Radiation therapy (RT) induces immune-mediated cell death and could generate a rich supply of tumor antigens if administered in the pre-operative, curative-intent setting. The addition of PD-1 mediated checkpoint blockade to pre-operative RT could thus, generate robust anti-tumor immune responses, induce long-term tumor-specific memory, and ultimately, improve cure rates. This study aims to establish the safety of pre-operative pembrolizumab (pembro)-mediated immune modulation with a RT “boost” equivalent in patients with operable triple negative breast cancer (TNBC) for whom lumpectomy and adjuvant RT are planned (NCT03366844). Serial research biopsies permit interrogation of conventional biomarkers including tumor infiltrating lymphocytes (TILs) and novel immune correlates as potential predictors of response to pembro alone versus pembro with RT.

Methods: Ten women with operable, primary TNBC >2cm for whom breast-conserving therapy is planned are being enrolled in this single-institution pilot study. Study treatment consists of 1 cycle of pre-operative pembro (200 mg IV) alone, followed 3 weeks later by a RT boost (24 Gy/3 fractions) to the primary breast tumor concurrently with pembro (+/- 5 days). Curative-intent, standard-of-care, neoadjuvant chemotherapy (NAC) or breast-conserving surgery is then undertaken within 8 weeks of study enrollment (i.e. within 5 weeks of pembro #2). Adjuvant RT is administered per standard-of-care after surgery, but without a boost dose. Research blood and fresh tumor biopsies are obtained at baseline and after cycles 1 and 2 of pembro. Co-primary endpoints are: 1) safety/tolerability, as defined by the number of patients who do not necessitate a delay in standard-of-care chemotherapy or surgery and 2) change in TIL score. Secondary endpoints include safety/toxicity up to 19 weeks after study enrollment, pCR rates and disease-free survival. Correlative analysis will include single-cell RNA sequencing of the tumor immune infiltrate and multispectral immunohistochemistry

Results: Seven patients enrolled between 12/19/17 and 7/1/18. As of 7/1/18, 5 patients have completed the experimental pembro/RT phase of the trial and are currently completing standard-of-care NAC; 1 patient is currently being treated in the experimental pembro/RT phase; and 1 patient with a cT2N0 tumor at baseline achieved a pathologic complete response (pCR, ypT0/Tis ypN0) after completing the experimental pembro/RT phase followed by anthracycline- and taxane-based NAC. No grade 3 or 4 toxicities have been observed during pembro/RT in the 6 patients completing the experimental phase to date. Three additional patients will be enrolled

Conclusions: This is the first trial of curative-intent, pre-operative checkpoint blockade with RT in breast cancer and the strategy appears to be well tolerated to date. At the time of presentation, safety, change in TIL score, and pCR rates for all patients completing the experimental and NAC phases of the study will be reported.

Citation Format: McArthur HL, Basho R, Shiao SL, Park D, Mita M, Chung A, Arnold B, Martin C, Dang C, Karlan S, Knott S, Giuliano A, Ho A. Preoperative pembrolizumab (Pembro) with radiation therapy (RT) in patients with operable triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-07.

Big data vs accurate data in health research: Large-scale physical activity monitoring, smartphones, wearable devices and risk of unconscious bias

Fundamental to the advancement of scientific knowledge is unbiased, accurate and validated measurement techniques. Recent United Nations and landmark Nature publications highlight the global uptake of mobile technology and the staggering potential for big data to encourage people to be physically active and to influence health policy. However, concerns exist about inconsistencies in smartphone health apps. Big data has many benefits, but noisy data may lead to wrong conclusions. In reaction to the increasing availability of low quality data; we call for a rigorous debate into the validity of substituting big data for accurate data in health research. We evaluated the step counting accuracy of a smartphone app previously used by 717,527 people from 111 countries. Our new data (from 48 participants; aged 21-59 years; body mass index 17.7-33.5 kg/m²) revealed significant (15-66%) undercounting by Apple phones. In contrast to the generally positive performances of wearable devices for stereotypical treadmill like walking, we observed extraordinarily large (0-200% of steps taken) error ranges for both Android and Apple phones. Unconscious bias (developers' perceptions of usual behaviour) may be embedded into many unvalidated smartphone apps. Consumer-grade wearable devices appear unsuitable to detect steps in people with slow, short or non-stereotypical gait patterns. Specifically, there is a risk of systematically undercounting the steps by obese people, females or people from different ethnic groups resulting in biases when reporting associations between physical inactivity and obesity. More research is required to develop smartphone apps suitable for all people of the heterogeneous global population.

Assessment of imatinib as first-line treatment of chronic myeloid leukemia: 10-year survival results of the randomized CML study IV and impact of non-CML determinants

Chronic myeloid leukemia (CML)-study IV was designed to explore whether treatment with imatinib (IM) at 400 mg/day (n=400) could be optimized by doubling the dose (n=420), adding interferon (IFN) (n=430) or cytarabine (n=158) or using IM after IFN-failure (n=128). From July 2002 to March 2012, 1551 newly diagnosed patients in chronic phase were randomized into a 5-arm study. The study was powered to detect a survival difference of 5% at 5 years. After a median observation time of 9.5 years, 10-year overall survival was 82%, 10-year progression-free survival was 80% and 10-year relative survival was 92%. Survival between IM400 mg and any experimental arm was not different. In a multivariate analysis, risk group, major-route chromosomal aberrations, comorbidities, smoking and treatment center (academic vs other) influenced survival significantly, but not any form of treatment optimization. Patients reaching the molecular response milestones at 3, 6 and 12 months had a significant survival advantage. For responders, monotherapy with IM400 mg provides a close to normal life expectancy independent of the time to response. Survival is more determined by patients' and disease factors than by initial treatment selection. Although improvements are also needed for refractory disease, more life-time can currently be gained by carefully addressing non-CML determinants of survival.

Adeno-associated viral serotypes differentially transduce inhibitory neurons within the rat amygdala

Recombinant adeno-associated viruses (AAV) are frequently used to make localized genetic manipulations within the rodent brain. It is accepted that the different viral serotypes possess differing affinities for particular cell types, but it is not clear how these properties affect their ability to transduce specific neuronal cell sub-types. Here, we examined ten AAV serotypes for their ability to transduce neurons within the rat basal and lateral nuclei of the amygdala (BLA) and the central nucleus of the amygdala (CeA). AAV2 based viral genomes designed to express either green fluorescent protein (GFP) from a glutamate decarboxylase (GAD65) promoter or the far-red fluorescent protein (E2-Crimson) from a phosphate-activated glutaminase (PAG) promoter were created and pseudotyped as AAV2/1, AAV2/4, AAV2/5, AAV2/6, AAV2/7, AAV 2/8, AAV2/9, AAV2/rh10, AAV2/DJ and AAV2/DJ8. These viruses were infused into the BLA and CeA at equal titers and twenty-one days later tissue within the amygdala was examined for viral transduction efficiency. These serotypes transduced neurons with similar efficiency, except for AAV4 and AAV5, which exhibited significantly less efficient neuronal transduction. Notably, AAV4 and AAV5 possess the most divergent capsid protein sequences compared to the other commonly available serotypes. We found that the Gad65-GFP virus did not exclusively express GFP within inhibitory neurons, as assessed by fluorescent in situ hybridization (FISH), but when this virus was used to transduce CeA neurons, the majority of the neurons that expressed GFP were in fact inhibitory neurons and this was likely due to the fact that this nucleus contains a very high percentage of inhibitory neurons.

Long-distance movement of phosphate starvation-responsive microRNAs in Arabidopsis

Plant microRNAs are small RNAs that are important for genetic regulation of processes such as plant development or environmental responses. Specific microRNAs accumulate in the phloem during phosphate starvation, and may act as long-distance signalling molecules. We performed quantitative PCR on Arabidopsis hypocotyl micrograft tissues of wild-type and hen1-6 mutants to assess the mobility of several phosphate starvation-responsive microRNA species. In addition to the previously confirmed mobile species miR399d, the corresponding microRNA* (miR399d*) was identified for the first time as mobile between shoots and roots. Translocation by phosphate-responsive microRNAs miR827 and miR2111a between shoots and roots during phosphate starvation was evident, while their respective microRNA*s were not mobile. The results suggest that long-distance mobility of microRNA species is selective and can occur without the corresponding duplex strand. Movement of miR399d* and root-localised accumulation of miR2111a* opens the potential for persisting microRNA*s to be mobile and functional in novel pathways during phosphate starvation responses.

Association between ankle equinus and plantar pressures in people with diabetes. A systematic review and meta-analysis

BACKGROUND

Diabetes is one of the most common chronic diseases in the world and is associated with a life-time risk of foot ulcer of 12-25%. Diabetes related restriction in ankle joint range of dorsiflexion is proposed to contribute to elevated plantar pressures implicated in the development of foot ulcers.

METHODS

A systematic search of EBSCO Megafile Premier (containing MEDLINE, CINAHL, SPORTSdiscus and Academic Search Complete) and The Cochrane Library was conducted to 23rd November 2016. Two authors independently reviewed and selected relevant studies. Meta-analysis of study data were conducted where possible.

FINDINGS

Fifteen studies met the inclusion criteria. Three studies were eligible to be included in the meta-analysis which found that equinus has a significant, but small, effect on increased plantar pressures (ES=0.26, CI 95% 0.11 to 0.41, p=0.001). Of the remaining studies, eight found evidence of an association between limited ankle dorsiflexion and increased plantar pressures while four studies found no relationship.

INTERPRETATION

Limited ankle joint dorsiflexion may be an important factor in elevating plantar pressures, independent of neuropathy. Limited ankle dorsiflexion and increased plantar pressures were found in all the studies where the sample population had a history of neuropathic foot ulceration. In contrast, the same association was not found in those studies where the population had neuropathy and no history of foot ulcer. Routine screening for limited ankle dorsiflexion range of motion in the diabetic population would allow for early provision of conservative treatment options to reduce plantar pressures and lessen ulcer risk.

Socioeconomic status and lifestyle behaviours in cancer survivors: smoking and physical activity

PURPOSE

Smoking cessation and increased physical activity (pa) have been linked to better outcomes in cancer survivors. We assessed whether socioeconomic factors influence changes in those behaviours after a cancer diagnosis.

METHODS

As part of a cross-sectional study, a diverse group of cancer survivors at the Princess Margaret Cancer Centre (Toronto, ON), completed a questionnaire about past and current lifestyle behaviours and perceptions about the importance of those behaviours with respect to their health. The influence of socioeconomic indicators on smoking status and physical inactivity at 1 year before and after diagnosis were assessed using multivariable logistic regression with adjustment for clinico-demographic factors.

RESULTS

Of 1222 participants, 1192 completed the smoking component. Of those respondents, 15% smoked before diagnosis, and 43% of those smokers continued to smoke after. The proportion of survivors who continued to smoke increased with lower education level (p = 0.03). Of the 1106 participants answering pa questions, 39% reported being physically inactive before diagnosis, of whom 82% remained inactive afterward. Survivors with a lower education level were most likely to remain inactive after diagnosis (p = 0.003). Lower education level, household income, and occupation were associated with the perception that pa had no effect or could worsen fatigue and quality of life (p ≤ 0.0001).

CONCLUSIONS

In cancer survivors, education level was a major modifier of smoking and pa behaviours. Lower socioeconomic status was associated with incorrect perceptions about pa. Targeting at-risk survivors by education level should be evaluated as a strategy in cancer survivorship programs.

A randomized, double-blind, placebo-controlled study of the effects of pomegranate extract on rising PSA levels in men following primary therapy for prostate cancer

BACKGROUND

The primary objective of this study was to compare the effects of pomegranate juice on PSA doubling times (PSADT) in subjects with rising PSA levels after primary therapy for prostate cancer.

METHODS

Double-blind, placebo-controlled multi-institutional study, evaluated the effects of pomegranate liquid extract on serum PSA levels. The primary end point of this study was change in serum PSADT. Additional secondary and exploratory objectives were to evaluate the safety of pomegranate juice and to determine the interaction of manganese superoxide dismutase (MnSOD) AA genotype and pomegranate treatment on PSADT.

RESULTS

One-hundred eighty-three eligible subjects were randomly assigned to the active and placebo groups with a ratio of 2:1 (extract N=102; placebo N=64; juice N=17). The majority of adverse events were of moderate or mild grade. Median PSADT increased from 11.1 months at baseline to 15.6 months in the placebo group (P<0.001) compared with an increase from 12.9 months at baseline to 14.5 months in the extract group (P=0.13) and an increase from 12.7 at baseline to 20.3 in the juice group (P=0.004). However, none of these changes were statistically significant between the three groups (P>0.05). Placebo AA patients experienced a 1.8 month change in median PSADT from 10.9 months at baseline to 12.7 months (P=0.22), while extract patients experienced a 12 month change in median PSADT from 13.6 at baseline to 25.6 months (P=0.03).

CONCLUSIONS

Compared with placebo, pomegranate extract did not significantly prolong PSADT in prostate cancer patients with rising PSA after primary therapy. A significant prolongation in PSADT was observed in both the treatment and placebo arms. Men with the MnSOD AA genotype may represent a group that is more sensitive to the antiproliferative effects of pomegranate on PSADT; however, this finding requires prospective hypothesis testing and validation.

Self administration of oxycodone alters synaptic plasticity gene expression in the hippocampus differentially in male adolescent and adult mice

Abuse and addiction to prescription opioids such as oxycodone (a short-acting Mu opioid receptor (MOP-r) agonist) in adolescence is a pressing public health issue. We have previously shown differences in oxycodone self-administration behaviors between adolescent and adult C57BL/6J mice and expression of striatal neurotransmitter receptor genes, in areas involved in reward. In this study, we aimed to determine whether oxycodone self-administration differentially affects genes regulating synaptic plasticity in the hippocampus of adolescent compared to adult mice, since the hippocampus may be involved in learning aspects associated with chronic drug self administration. Hippocampus was isolated for mRNA analysis from mice that had self administered oxycodone (0.25 mg/kg/infusion) 2h/day for 14 consecutive days or from yoked saline controls. Gene expression was analyzed with real-time polymerase chain reaction (PCR) using a commercially available "synaptic plasticity" PCR array containing 84 genes. We found that adolescent and adult control mice significantly differed in the expression of several genes in the absence of oxycodone exposure, including those coding for mitogen-activated protein kinase, calcium/calmodulin-dependent protein kinase II gamma subunit, glutamate receptor, ionotropic AMPA2 and metabotropic 5. Chronic oxycodone self administration increased proviral integration site 1 (Pim1) and thymoma viral proto-oncogene 1 mRNA levels compared to controls in both age groups. Both Pim1 and cadherin 2 mRNAs showed a significant combined effect of Drug Condition and Age × Drug Condition. Furthermore, the mRNA levels of both cadherin 2 and cAMP response element modulators showed an experiment-wise significant difference between oxycodone and saline control in adult but not in adolescent mice. Overall, this study demonstrates for the first time that chronic oxycodone self-administration differentially alters synaptic plasticity gene expression in the hippocampus of adolescent and adult mice.