Understanding lifetime and dispersion of cough-emitted droplets in air

To understand the exact transmission routes of SARS-CoV-2 and to explore effects of time, space and indoor environment on the dynamics of droplets and aerosols, rigorous testing and observation must be conducted. In the current work, the spatial and temporal dispersions of aerosol droplets from a simulated cough were comprehensively examined over a long duration (70 min). An artificial cough generator was constructed to generate reliably repeatable respiratory ejecta. The measurements were performed at different locations in front (along the axial direction and off-axis) and behind the source in a sealed experimental enclosure. Aerosols of 0.3-10 µm (around 20% of the maximum nuclei count) were shown to persist for a very long time in a still environment, and this has a substantial implication for airborne disease transmission. The experiments demonstrated that a ventilation system could reduce the total aerosol volume and the droplet lifetime significantly. To explain the experimental observations in more detail and to understand the droplet in-air behaviour at various ambient temperatures and relative humidity, numerical simulations were performed using the Eulerian-Lagrangian approach. The simulations show that many of the small droplets remain suspended in the air over time instead of falling to the ground.

Muscle protein anabolism in advanced cancer patients: response to protein and amino acids support, and to physical activity

In the field of oncology, it is well recognized that a decrease in mass, density, strength, or function of skeletal muscle is associated to increased treatment toxicities and postoperative complications, as well as poor progression-free survival and overall survival. The ability of amino acids to stimulate protein synthesis in cancer patients is reduced. Considering nutritional intervention, this anabolic resistance could be in a part counteracted by increasing protein or by giving specific amino acids. In particular, Leucine might counteract this anabolic resistance not only by increasing substrate availability, but also by directly modulating the anabolic signal pathway. Few studies showed the possibility of increasing muscle protein synthesis by specific nutriments and/or by increasing amino acids or protein administration. In addition, whereas many studies provide evidence of a benefit of adapted physical activity in advanced cancer patients, it is difficult to specify the most appropriate type of exercise, and the optimum rhythm and intensity. Moreover, the benefits of physical activities and of protein support seem greater when it is started at the precachexia stage rather than at the cachexia stage, and their benefits are limited or nonexistent at the stage of refractory cachexia. Future approaches should integrate the combination of several complementary treatments in order to prevent (or improve) cachexia and/or sarcopenia in cancer patients.

Composition effect on thermophobicity of ternary mixtures: An enhanced molecular dynamics method

Thermodiffusion or the Ludwig-Soret effect is known as the cross effect between the temperature gradient and induced separation of mixture species in multicomponent mixtures. The performance of the boundary driven non-equilibrium molecular dynamics enhanced heat exchange (eHEX) algorithm was validated by evaluating the sign and magnitude of the thermodiffusion process in methane/n-butane/n-dodecane (nC₁-nC₄-nC₁₂) ternary mixtures. The eHEX algorithm consists of an extended version of the HEX algorithm with an improved energy conservation property. In addition to this, the transferable potentials for phase equilibria-united atom augmented force field was employed in all molecular dynamics (MD) simulations to accurately represent molecular interactions in the fluid. Our newly employed MD algorithm was capable to appropriately reflect the thermophobicity concept and the coupled effect of relative density and mole fraction of the mixture species on the thermodiffusion process. The separation ratio of the ternary mixture for five different compositions (at 333.15 K and 35 MPa) showed good agreement with experimental data and better accuracy in predicting the sign change of the intermediate component (nC₄) as its concentration in the mixture increases, when compared to other MD models.

[Pulmonary tumor thrombotic microangiopathy]

Pulmonary tumor thrombotic microangiopathy syndrome is a rare clinicopathological entity in which tumor cell micro-emboli in the pulmonary microcirculation induced thrombotic microangiopathy. This can cause respiratory failure, and acute or sub-acute right heart failure. Histological features include micro tumor emboli in the small arteries and arterioles of the lung associated with thrombus formation and fibro-cellular and fibro-muscular intimal proliferation. The diagnosis is however extremely difficult to make before death. Thus, most of the observations reported are based on autopsy data. Very rare diagnostic observations made before death suggest the potential effectiveness of chemotherapy. Many details remain to be elucidated, interdisciplinary research is a priority with close collaboration between pathologists and clinicians to better understand this, often fatal, syndrome. It may be that the use of targeted therapies will improve the very poor prognosis allowing survival of several weeks or months after diagnosis.

Low skeletal muscle is associated with toxicity in patients included in phase I trials

BACKGROUND

Low muscle mass has been associated with chemotherapy toxicity. We conducted this prospective study to evaluate the effects of body composition on the occurrence of toxicity in phase I trials.

PATIENTS AND METHODS

Patients were consecutively enrolled irrespective of the type of tumor or the type of drug. The Skeletal Muscle Index (SMIndex) and visceral and subcutaneous adipose tissue were assessed with computed tomography imaging by measuring cross-sectional areas of the tissues (cm(2)/m(2)). Dose-limiting toxicity (DLT) corresponded to toxicities occurring during the 1(st) cycle that necessitated dose reduction, postponement or interruption of drug administration and severe toxicity events (STE) corresponded to DLT or permanent treatment withdrawal due to toxicity.

RESULTS

93 patients were evaluated. Ten percent of patients experienced DLT and had a lower SMIndex: 40.8 ± 4.6 vs. 48.1 ± 9.6 cm(2)/m(2) (p = 0.01). STE occurred in 14 % of the patients. The only factor associated with STE was a low SMIndex: 42.4 ± 5.8 vs. 48.4 ± 9.7 cm(2)/m(2) (p = 0.02). STE were observed in 25.5 % of the patients when the SMIndex was below the median value compared to 6.5 % of patients with a high SMIndex (p = 0.02).

CONCLUSION

Muscle mass is a critical predictor of severe toxicity events in phase I patients, suggesting that sarcopenia may be considered in assessing patients for eligibility of phase-1 studies.

[Managing nutritional support in thoracic oncology]

INTRODUCTION

Cancer treatments are based on specific anticancer chemotherapy. However, there is increasing interest in general aspects of care, which are increasingly evidence based.

STATE OF THE ART

The importance of muscle mass is becoming increasingly evident. Its role is not only limited to the maintenance of physical performance and quality of life. In oncology, recent studies have shown a close link between sarcopenia (low muscle mass) and mortality as well as between sarcopenia and chemotherapy toxicity. To treat malnutrition and the lack of energy intake, nutritional support is considered, whether through the prescription of oral nutritional supplements, enteral nutrition or even parenteral nutrition. Scientific arguments are often absent and few studies have been carried out in patients with lung cancer.

PERSPECTIVES

There are many experimental arguments and a few clinical trials that support using omega 3 fatty acids to modulate inflammatory reaction and to reduce its consequences on muscular proteolysis. The benefit of regular physical activity has already been proven in chronic respiratory disease and its use in association with nutritional support must be recommended in oncologic care.

CONCLUSION

Given the increasing recognition of the role of muscle mass in cancer, the purpose of any nutritional support must be focused on increasing muscle anabolism and decreasing proteolysis.

Effect of everolimus therapy on skeletal muscle wasting in patients with metastatic renal cell carcinoma (mRCC): Results from a placebo-controlled study

319

Background: We have previously reported that sorafenib induces muscle wasting in mRCC (Antoun, JCO 2010). As everolimus exerts its antineoplastic through inhibition of the mammalian target of rapamycin (mTOR), a key element of intracellular signalling of protein synthesis in skeletal muscle, we hypothesized that muscle wasting would be also an important side effect of everolimus therapy.

Methods: All patients with mRCC enrolled in RECORD 1 (everolimus (E) or placebo (P) post TKI failure) in IGR (n=40) were analyzed for this study. Patients were eligible if at least 2 CT scans were available. CT image analysis, which has high precision and specificity for evaluation of specific muscles, was used to define change in total skeletal muscle. The third lumbar vertebra (L3) was chosen as a landmark. Images were analyzed using Slice-O-Matic software V4.3 (Tomovision). Tissue Hounsfield unit thresholds were employed: −29 to +150 for skeletal muscle. Subsequently, tissue cross-sectional areas (cm2) were computed.

Results: 35 patients (83% male, median age 60y) were evaluable, 10 on P and 25 on E. In addition, 9 patients initially on P could cross to E (as per protocol) and were analyzed both on P and on E. Median durations of treatment were 79 and 263 days respectively on P and E. Placebo patients had stable body weight, with no significant mean gain or loss of muscle. By contrast, patients on E lost body weight over time: −2.5±3.6 kg by 83 d (p=0.02), −4.9±5.7 (p=0.005) by 167 d and –5.0±7.6 kg (p=0.02) by 286 d. E patients progressively lost skeletal muscle compared .with baseline from −2.5±5.9% at 83d (p=0.06), to −4.0±7.5% at 167d (p=0.03) and −4.8±6.8% at 263d (p=0.01). Interstingly, the 9 patients who had maintained body weight (+2.0 kg) and muscle (+2.7%) whilst on placebo, and crossed to E, promptly lost weight (−4.8 kg, p<0.03) and skeletal muscle (−5.3%) (about 1.5 kg of muscle) when crossed to E.

Conclusions: Body weight and muscle wasting are induced by everolimus in mRCC, and are not related to progressive disease. These changes increase over time. Relation between these changes and outcome will be presented at the meeting.

[Table: see text]

Low body mass index and sarcopenia associated with dose-limiting toxicity of sorafenib in patients with renal cell carcinoma

BACKGROUND

Patients with severe depletion of skeletal muscle (sarcopenia) are prone to dose-limiting toxicity (DLT) during fluoropyrimidine therapy. We hypothesized that sarcopenia may also predict toxicity of targeted therapy drugs.

MATERIALS AND METHODS

Metastatic renal cell cancer (RCC) patients (n = 55) received sorafenib 400 mg b.i.d. Weight, height and skeletal muscle cross-sectional area at the third lumbar vertebra were measured by computed tomography (CT). Toxicity was assessed.

RESULTS

DLT occurred in 22% of patients overall, of which three-quarters were dose reductions to 400 mg and the remainder entailed termination of treatment. DLT was most common (41%) in sarcopenic patients whose body mass index (BMI) was <25 kg/m(2) and least common (13%) in patients who were not sarcopenic and/or overweight or obese (P = 0.03). Toxicity was especially prevalent in sarcopenic male patients with BMI < 25, with 71% of men with these characteristics being unable to continue treatment at 800 mg/day. By contrast, only 5% of male patients whose muscle index was above the cut-off for sarcopenia and only 11% of male patients whose BMI was >25 experienced a DLT.

CONCLUSION

BMI < 25 kg/m(2) with diminished muscle mass is a significant predictor of toxicity in metastatic RCC patients treated with sorafenib.

[Evaluating the nutritional status of a lung cancer patient is an important element in patient management]

Nutritional status assessment during the comprehensive management of patients treated for cancer is becoming increasingly necessary. Various data are currently available which show a relationship between the nutritional status and certain morbidity-mortality parameters. In contrast, there is a paucity of data concerning lung cancer. A relationship between survival and the nutritional status has been found in the literature, exclusively in advanced stages of lung cancer. Unlike that observed in oncological digestive tract surgery, where artificial nutrition is recommended preoperatively in severely malnourished patients, no link has been evidenced between postoperative morbidity and mortality and the preoperative nutritional status in lung surgery. The scientific nutritional societies simply recommend preoperative nutritional assessment. Reflection on management of malnourished patients receiving chemotherapy is still "archaic" and recent studies and recommendations are lacking. Although largely prescribed, oral nutritional supplements have not proven efficient and patient compliance will probably have to be improved. According to "good nutrition practice" rules, the digestive tube should be used when it is functional and in theory, enteral nutrition is indicated in this situation. In addition to the lack of clinical studies, one of the obstacles to its use is cultural with the need to obtain not only patient approval but also that of the prescriber. Parenteral nutrition was discredited in earlier studies. It should probably be reevaluated in the context of new chemotherapeutic molecules and a different way of handling nutrition care. The physiological concept of omega-3 fatty acid modulation of inflammation is of interest in animal studies but the clinical modalities of use remain to be defined and determined. The role of nutrition in the management of lung cancer is still very limited but there are major expectations and many solutions are awaited in the coming years.

[Fever and infectious complications in patient with lung cancer]

The respiratory infections are very frequent during lung cancer. Their diagnosis is often difficult because of the various etiologies (cancer, chemotherapy, radiotherapy) and this complexity can make discuss a preliminary bronchial exploration before any therapeutics. When it is about a located infection, germs in cause are often the same that in the community respiratory infections, in particular bacilli Gram negative, and it is thus logical to treat by the penicillin A. In front of an interstitial syndrome, it is necessary to evoke the opportunist infections, which are increasing in patients with cancer because of the multimodality therapeutic and the elongation of the survival. The neutropenic patient must be distinguished because of its specificities. The pulmonary infections lead to an important mortality. According to the patient (advanced age, underlying chronic obstructive pulmonary disease [COPD]) and to the treatment (chemotherapy, pneumonectomy), prevention must be discussed as the pneumococcal and Haemophilus influenzae vaccination.

Chemotherapy for poor prognosis non seminomatous germ cell tumors (NSGCT): Should doses be reduced at first cycle to prevent acute respiratory distress syndrome (ARDS) in patients with multiple lung metastases?

5087

Background: Patients with multiple lung metastases from NSGCT and dyspnea at presentation are at high risk of ARDS and death in the first days after chemotherapy induction. This entity has been designated the “choriocarcinoma syndrome” or “very high risk NSGCT”. It is linked to acute intra-alveolar hemorrhage related to early tumor necrosis, which in turn, may be complicated by pulmonary infection promoted by neutropenia. To try to avoid this complication, The policy to manage these patients was changed at Institut Gustave Roussy in 1997. Methods: Data from all patients with lung metastases from NSGCT and dyspnea or a pO2 < 80 and treated between1980–2006 in our institution were collected. Patients were treated in a specialized intensive care unit. From 1980–1997, the first cycle of chemotherapy consisted in a full dose regimen. After 1997, it consisted in a 3-day reduced induction regimen of EP (cisplatin 20 mg/m2/day and etoposide 100 mg/m2/day), with bleomycin and two additional days of EP being postponed to day 15, and the regular BEP regimen being started at day 21. Results: 25 patients with a poor risk NSGCT according to the IGCCCG classification had extensive lung metastases plus either dyspnea at presentation (n=6) or a pO2<80 (n=2), or both criteria (n=17). Median age was 30 years (range 18–49). Median hCG was 200,000 UI (range 11–8,920,000) and 18/25 (72%) patients also had non-pulmonary visceral metastases. During the 1980–1997 period, 13/15 patients (87%) developed ARDS, of whom 10 died, and only 4/15 (27%) patients were long-term survivors. In contrast, during the 1997-2006 period, only 3/10 patients (30%) developed ARDS, of whom 2 died, and 4/10 (40%) survived. Conclusions: Reducing doses of chemotherapy during the first cycle of chemotherapy for poor-prognosis NSGCT with extensive and symptomatic lung metastases seems to prevent the risk of early death due to ARDS and should therefore be recommended.

No significant financial relationships to disclose.

Prospective evaluation of clinical and biological parameters to predict clinically relevant denutrition in cancer patients undergoing surgery

18611

Background: Denutrition increases surgery morbidity and mortality in cancer patients. Methods: This study aimed to compare the relative value of different scores widely used to measure denutrition. During 3 months for all of the patients requiring heavy carcinologic surgery we checked: weight loss over 10%, body mass index (BMI), serum albumin, transthyretin (Tt), Buzby index, Pronostic Inflammatory Nutritional Index (PINI), Ottery score (PG-SGA). Other data like the surgical procedure, duration of surgery, cancer status were also recorded. Morbidity was defined by infectious and non-infectious major complications (IMC, NIMC), length of stay (Ls) in hospital, and death at 1 and 6 months. Results: 275 patients from 8 French Cancer Centers were included (167 were female, median age: 58 years). In multivariate analyses albumin level (<30 g/l) is the only significant predictor of surgical morbidity, with the duration of the surgical procedure. Ottery score was the most sensitive among clinical parameters. Weight loss was significantly correlated with survival. Conclusions: Serum albumin and weight loss are useful parameters to consider in cancer patient requiring surgery; they are easy to monitor and should be part of pre-operative check-up in those patients.

[Table: see text]

No significant financial relationships to disclose.

Incidence and clinical significance of anaerobic bacteraemia in cancer patients: a 6-year retrospective study

Recent studies have shown that anaerobes account for 0.5-9% of all episodes of bacteraemia in hospitalised patients, with variations according to geographical location and demographic characteristics, most notably age, but few data are available for cancer patients. This study investigated retrospectively the incidence of anaerobic bacteraemia in cancer patients who received non-surgical treatment over a 6-year period at a tertiary oncology centre. Gastrointestinal (27%) and haematological (29%) malignancies were the most common underlying diseases. Among 45 isolates of anaerobic bacteria recovered from 45 patients, Bacteroides spp. and Clostridium spp. were the most frequent pathogens (60% and 22%, respectively). Twenty episodes of bacteraemia were polymicrobial, most frequently with aerobic Gram-negative bacilli (18 cases). The mortality rate for patients with adequate antimicrobial therapy from the outset was 14%, compared with 63% for patients who were not treated adequately at any time.

[Usefulness of panfungal PCR for the diagnosis of fungal infection in immunocompromised patients]

The diagnostic of invasive fungal infection is often difficult because of the low sensitivity of fungal culture from infected tissues. Here we have assessed the ability of a panfungal PCR targeted on the DNA region encoding the RNA genes followed by sequencing of the amplification products to detect and identify fungi from tissue biopsies. This assay allowed us to identify the microorganism responsible for an invasive fungal infection in three of our patients. In two cases, hepatosplenic candidiasis was suspected and Candida albicans DNA was detected from liver biopsies. The third patient was cared for a thymome and developed a manubrium osteitis caused by Scedosporium apiospermum.