This paper presents insights into the lived experience of maritime carpentry practices, based on six months of sensory-ethnographic fieldwork as a wooden boat builder’s apprentice. In particular, the ...author explores the widely-reported experience of tools ‘withdrawing’ from consciousness as craftspeople master their use. Without contradicting these interpretations – many of which are constructed by way of reference to ideas from Merleau-Ponty – the author suggests further theoretical resources to examine the perceptual experience of work after tools cease to be the main focus of the craftsperson’s attention. Heidegger’s idea of ‘circumspection’ is presented as a way to illuminate the relational nature of the subsequent mode of perception, in which the work as a whole fills the consciousness, rather than the individual instruments through which the work is achieved.
To provide evidence-based recommendations on the treatment of multiple myeloma to practicing physicians and others.
ASCO and Cancer Care Ontario convened an Expert Panel of medical oncology, surgery, ...radiation oncology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and some phase II studies published from 2005 through 2018. Outcomes of interest included survival, progression-free survival, response rate, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.
The literature search identified 124 relevant studies to inform the evidence base for this guideline.
Evidence-based recommendations were developed for patients with multiple myeloma who are transplantation eligible and those who are ineligible and for patients with relapsed or refractory disease.
Summary
Many algae are auxotrophs for vitamin B12 (cobalamin), which they need as a cofactor for B12‐dependent methionine synthase (METH). Because only prokaryotes can synthesize the cobalamin, they ...must be the ultimate source of the vitamin. In the laboratory, a direct interaction between algae and heterotrophic bacteria has been shown, with bacteria supplying cobalamin in exchange for fixed carbon. Here we establish a system to study this interaction at the molecular level. In a culture of a B12‐dependent green alga Chlamydomonas nivalis, we found a contaminating bacterium, identified by 16S rRNA analysis as Mesorhizobium sp. Using the sequenced strain of M. loti (MAFF303099), we found that it was able to support the growth of B12‐dependent Lobomonas rostrata, another green alga, in return for fixed carbon. The two organisms form a stable equilibrium in terms of population numbers, which is maintained over many generations in semi‐continuous culture, indicating a degree of regulation. However, addition of either vitamin B12 or a carbon source for the bacteria perturbs the equilibrium, demonstrating that the symbiosis is mutualistic and facultative. Chlamydomonas reinhardtii does not require B12 for growth because it encodes a B12‐independent methionine synthase, METE, the gene for which is suppressed by addition of exogenous B12. Co‐culturing C. reinhardtii with M. loti also results in reduction of METE expression, demonstrating that the bacterium can deliver the vitamin to this B12‐independent alga. We discuss the implications of this for the widespread distribution of cobalamin auxotrophy in the algal kingdom.
The unique acute effects of the large fractional doses that characterize stereotactic radiosurgery (SRS) or radiotherapy (SRT), specifically in terms of antitumor immune cellular processes, vascular ...damage, tumor necrosis, and apoptosis on brain metastasis have yet to be empirically demonstrated. The objective of this study is to provide the first in-human evaluation of the acute biological effects of SRS/SRT in resected brain metastasis. Tumor samples from patients who underwent dose-escalated preoperative SRT followed by resection with available non-irradiated primary tumor tissues were retrieved from our institutional biorepository. All primary tumors and irradiated metastases were evaluated for the following parameters: tumor necrosis, T-cells, natural killer cells, vessel density, vascular endothelial growth factor, and apoptotic factors. Twenty-two patients with irradiated and resected brain metastases and paired non-irradiated primary tumor samples met inclusion criteria. Patients underwent a median preoperative SRT dose of 18 Gy (Range: 15-20 Gy) in 1 fraction, with 3 patients receiving 27-30 Gy in 3-5 fractions, followed by resection within median interval of 67.8 h (R: 18.25-160.61 h). The rate of necrosis was significantly higher in irradiated brain metastases than non-irradiated primary tumors (p < 0.001). Decreases in all immunomodulatory cell populations were found in irradiated metastases compared to primary tumors: CD3 + (p = 0.003), CD4 + (p = 0.01), and CD8 + (p = 0.01). Pre-operative SRT is associated with acute effects such as increased tumor necrosis and differences in expression of immunomodulatory factors, an effect that does not appear to be time dependent, within the limited intervals explored within the context of this analysis.
The purpose of this study was to critically analyze the risk of unplanned readmission following resection of brain metastasis and to identify key risk factors to allow for early intervention ...strategies in high-risk patients. We analyzed data from the Nationwide Readmissions Database (NRD) from 2010-2014, and included patients who underwent craniotomy for brain metastasis, identified using ICD-9-CM diagnosis (198.3) and procedure (01.59) codes. The primary outcome of the study was unplanned 30-day all-cause readmission rate. Secondary outcomes included reasons and costs of readmissions. Hierarchical logistic regression model was used to identify the factors associated with 30-day readmission following craniotomy for brain metastasis. During the study period, 44,846 index hospitalizations occurred for patients who underwent resection of brain metastasis. In this cohort, 17.8% (n = 7,965) had unplanned readmissions within the first 30 days after discharge from the index hospitalization. The readmission rate did not change significantly during the five-year study period (p-trend = 0.286). The median per-patient cost for 30-day unplanned readmission was $11,109 and this amounted to a total of $26.4 million per year, which extrapolates to a national expenditure of $269.6 million. Increasing age, male sex, insurance status, Elixhauser comorbidity index, length of stay, teaching status of the hospital, neurological complications and infectious complications were associated with 30-day readmission following discharge after an index admission for craniotomy for brain metastasis. Unplanned readmission rates after resection of brain metastasis remain high and involve substantial healthcare expenditures. Developing tools and interventions to prevent avoidable readmissions could focus on the high-risk patients as a future strategy to decrease substantial healthcare expense.
Malignant transformation (MT) of adult grade 2 glioma (low-grade glioma LGG) is associated with adverse survival. We sought to describe the incidence, outcomes, and risk factors for MT of molecularly ...classified LGG.
We reviewed a single-institutional database of adults who received a diagnosis of LGG with data allowing for molecular classification from 1980 to 2018 to evaluate time to MT and its associated risk factors. MT was defined as pathologic confirmation of grade 3-4 glioma and/or imaging characteristics consistent with MT by multidisciplinary consensus.
Among the included 486 adults with molecularly classified LGG, median age was 39 years (range, 18-78), median tumor size was 3.9 cm (range, 0.3-13.0), and 262 (54%) were male. Molecular classification was IDH
1p/19q
in 169 (35%), IDH
1p/19q
in 125 (26%), and IDH
in 192 (40%) patients. Adjuvant management was observation in 246 (51%) patients, temozolomide alone in 82 (16%), radiation therapy alone in 63 (13%), and radiation therapy concurrent with temozolomide in 81 (17%). Temozolomide monotherapy was more likely to be given to IDH
1p/19q
patients (P < .001). Median follow-up was 5.3 years. MT occurred in 84 (17%) patients, with a 5-year freedom from MT of 86% (95% confidence interval CI, 82%-90%). Median overall survival after MT was 2.4 years (95% CI, 1.5-3.3) and was associated with molecular classification (P = .03) and grade at MT (P < .001). Factors associated with MT were male sex (hazard ratio HR, 2.1; 95% CI, 1.2-3.6; P = .009), tumor size ≥5 cm (HR, 3.5; 95% CI, 2.0-6.2; P < .001), IDH
1p/19q
(HR, 2.7; 95% CI, 1.3-5.6; P = .009) or IDH
classification (HR, 5.5; 95% CI, 2.5-11.8; P < .001), and adjuvant temozolomide monotherapy (HR, 3.8; 95% CI, 1.4-10.3; P = .008).
MT of LGG has a poor prognosis associated with unfavorable molecular groups. Analysis of our large cohort identified adjuvant temozolomide monotherapy as the only modifiable risk factor for MT and provides the first clinical evidence of temozolomide-associated MT among molecularly classified adult LGG. This novel finding supplements our understanding of temozolomide-induced hypermutation and informs precision management of LGG.
Brain metastasis (BM) represents a common complication of cancer, and in the modern era requires multi-modal management approaches and multi-disciplinary care. Traditionally, due to the limited ...efficacy of cytotoxic chemotherapy, treatment strategies are focused on local treatments alone, such as whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and resection. However, the increased availability of molecular-based therapies with central nervous system (CNS) penetration now permits the individualized selection of tailored systemic therapies to be used alongside local treatments. Moreover, the introduction of immune checkpoint inhibitors (ICIs), with demonstrated CNS activity has further revolutionized the management of BM patients. The rapid introduction of these cancer therapeutics into clinical practice, however, has led to a significant dearth in the published literature about the optimal timing, sequencing, and combination of these systemic therapies along with SRS. This manuscript reviews the impact of tumor biology and molecular profiles on the management paradigm for BM patients and critically analyzes the current landscape of SRS, with a specific focus on integration with systemic therapy. We also discuss emerging treatment strategies combining SRS and ICIs, the impact of timing and the sequencing of these therapies around SRS, the effect of corticosteroids, and review post-treatment imaging findings, including pseudo-progression and radiation necrosis.
In the treatment of patients with metastatic cancer, the current paradigm states that metastasis-directed therapy does not prolong life. This paradigm forms the basis of clinical trial null ...hypotheses, where trials are built to test the null hypothesis that patients garner no overall survival benefit from targeting metastatic lesions. However, with advancing imaging technology and increasingly precise techniques for targeting lesions, a much larger proportion of metastatic disease can be treated. As a result, the life-extending benefit of targeting metastatic disease is becoming increasingly clear.
In this work, we suggest shifting this qualitative null hypothesis and describe a mathematical model that can be used to frame a new, quantitative null. We begin with a very simple formulation of tumor growth, an exponential function, and illustrate how the same intervention (removing a given number of cells from the tumor) at different times affects survival. Additionally, we postulate where recent clinical trials fit into this parameter space and discuss the implications of clinical trial design in changing these quantitative parameters.
Our model shows that although any amount of cell kill will extend survival, in many cases the extent is so small as to be unnoticeable in a clinical context or is outweighed by factors related to toxicity and treatment time.
Recasting the null in these quantitative terms will allow trialists to design trials specifically to increase understanding of the circumstances (patient selection, disease burden, tumor growth kinetics) that can lead to improved overall survival when targeting metastatic lesions, rather than whether targeting metastases extends survival for patients with (oligo-) metastatic disease.
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