The microbiome and cancer.

Humans coexist with a vast bacterial, fungal and viral microbiome with which we have coevolved for millions of years. Several long recognized epidemiological associations between particular bacteria and cancer are now understood at the molecular level. At the same time, the arrival of next-generation sequencing technology has permitted a thorough exploration of microbiomes such as that of the human gut, enabling observation of taxonomic and metabolomic relationships between the microbiome and cancer. These studies have revealed causal mechanisms for both microbes within tumours and microbes in other host niches separated from tumours, mediated through direct and immunological mechanisms. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

COMPARATIVE BIOAVAILABILITY ANALYSIS OF ORAL ALENDRONATE SODIUM FORMULATIONS IN PAKISTAN.

Alendronate sodium, a bisphosphonate drug, it is used to treat osteoporosis and other bone diseases. The present study was designed to conduct comparative bioavailability analysis of oral formulations of aledronate sodium through an open-label, randomized, 2-sequence, 2-period crossover study. Healthy adult male Pakistani volunteers received a single 70 mg dose of the test or reference formulation of alendronate sodium followed by a 7 day washout period. Plasma drug concentrations were determined using a validated HPLC post column fluorescence derivatization method. AUC(01,) AUC(0-8,) C(max). and T(max) were determined by non-compartmental analysis and were found within the permitted range of 80% to 125% set by the US Food and Drug Administration (FDA). Results show that both in vitio and in vivo assays of all test brands were within the spec- ification of the US Pharmacopoeial limits and were statistically bioequivalent. No adverse events were reported in this study.

Updated patterns of failure after multimodality therapy for malignant pleural mesothelioma.

OBJECTIVE: We have previously described patterns of failure after extrapleural pneumonectomy and multimodality therapy for malignant pleural mesothelioma and sought to update our results with a larger cohort of recent patients. METHODS: A total of 169 patients underwent extrapleural pneumonectomy without preoperative chemotherapy between 2001 and 2010. Data for treatment, recurrence, and survival were determined from medical records. A thoracic radiologist reviewed postoperative computed tomography or positron emission tomography computed tomography scans to determine sites of recurrence. Time to recurrence was estimated by the Kaplan-Meier method. Rates were compared using the Fisher exact test. RESULTS: The median age of patients was 62 years. Histology on final pathology was epithelial for 104 patients (62%) and nonepithelial for 65 patients (38%). A total of 132 patients (78%) received heated intraoperative chemotherapy; 77 patients (45%) received adjuvant chemotherapy, and 71 patients (42%) received adjuvant radiation therapy. Most chemotherapy regimens included platinum or pemetrexed. Median radiation therapy dose was 54 Gy. Among 158 evaluable patients, a recurrence developed in 118 (75%). Median follow-up was 83 months, median time to recurrence was 13.1 months, and median survival was 15 months. Sites of first recurrence were in the ipsilateral hemithorax or mediastinum for 54% of patients, in the abdomen for 39% of patients, in the contralateral hemithorax for 28% of patients, and in other distant sites for 5% of patients. Some patients had simultaneous recurrences in multiple sites. CONCLUSIONS: The most common site of recurrence after extrapleural pneumonectomy and planned multimodality therapy remains the ipsilateral hemithorax (including mediastinum), and true distant failure (other than the abdomen or contralateral hemithorax) remains unusual. The distribution of recurrences is strikingly similar to our prior report.

Lis1 regulates dynein by sterically blocking its mechanochemical cycle.

Regulation of cytoplasmic dynein's motor activity is essential for diverse eukaryotic functions, including cell division, intracellular transport, and brain development. The dynein regulator Lis1 is known to keep dynein bound to microtubules; however, how this is accomplished mechanistically remains unknown. We have used three-dimensional electron microscopy, single-molecule imaging, biochemistry, and in vivo assays to help establish this mechanism. The three-dimensional structure of the dynein-Lis1 complex shows that binding of Lis1 to dynein's AAA+ ring sterically prevents dynein's main mechanical element, the 'linker', from completing its normal conformational cycle. Single-molecule experiments show that eliminating this block by shortening the linker to a point where it can physically bypass Lis1 renders single dynein motors insensitive to regulation by Lis1. Our data reveal that Lis1 keeps dynein in a persistent microtubule-bound state by directly blocking the progression of its mechanochemical cycle.

Reconstitution of dynein transport to the microtubule plus end by kinesin.

Cytoplasmic dynein powers intracellular movement of cargo toward the microtubule minus end. The first step in a variety of dynein transport events is the targeting of dynein to the dynamic microtubule plus end, but the molecular mechanism underlying this spatial regulation is not understood. Here, we reconstitute dynein plus-end transport using purified proteins from S. cerevisiae and dissect the mechanism using single-molecule microscopy. We find that two proteins-homologs of Lis1 and Clip170-are sufficient to couple dynein to Kip2, a plus-end-directed kinesin. Dynein is transported to the plus end by Kip2, but is not a passive passenger, resisting its own plus-end-directed motion. Two microtubule-associated proteins, homologs of Clip170 and EB1, act as processivity factors for Kip2, helping it overcome dynein's intrinsic minus-end-directed motility. This reveals how a minimal system of proteins transports a molecular motor to the start of its track.DOI: http://dx.doi.org/10.7554/eLife.02641.001.

Engineering defined motor ensembles with DNA origami.

Many cytoskeletal motors function in groups to coordinate the spatial and temporal positioning of cellular cargo. While methods to study the biophysical properties of single motors are well established, methods to understand how multiple motors work synergistically or antagonistically are less well developed. Here, we describe a three-dimensional synthetic cargo structure made using DNA origami, which can be used to template defined numbers and types of cytoskeletal motors with programmable geometries and spacing. We describe methods for building the DNA origami structure, covalently attaching motors to DNA, forming the motor-DNA origami structure complex, and single-molecule assays to examine the motile properties of motor ensembles.

Engineered, harnessed, and hijacked: synthetic uses for cytoskeletal systems.

Synthetic biology re-imagines existing biological systems by designing and constructing new biological parts, devices, and systems. In the arena of cytoskeleton-based transport, synthetic approaches are currently used in two broad ways. First, molecular motors are harnessed for non-physiological functions in cells. Second, transport systems are engineered in vitro to determine the biophysical rules that govern motility. These rules are then applied to synthetic nanotechnological systems. We review recent advances in both of these areas and conclude by discussing future directions in engineering the cytoskeleton and its motors for transport.

Dynein achieves processive motion using both stochastic and coordinated stepping.

Processivity, the ability of single molecules to move continuously along a track, is a fundamental requirement of cargo-transporting molecular motors. Here, we investigate how cytoplasmic dynein, a homodimeric, microtubule-based motor, achieves processive motion. To do this, we developed a versatile method for assembling Saccharomyces cerevisiae dynein heterodimers, using complementary DNA oligonucleotides covalently linked to dynein monomers labeled with different organic fluorophores. Using two-color, single-molecule microscopy and high-precision, two-dimensional tracking, we find that dynein has a highly variable stepping pattern that is distinct from all other processive cytoskeletal motors, which use 'hand-over-hand' mechanisms. Uniquely, dynein stepping is stochastic when its two motor domains are close together. However, coordination emerges as the distance between motor domains increases, implying that a tension-based mechanism governs these steps. This plasticity may allow tuning of dynein for its diverse cellular functions.

Characteristics and outcomes of trauma patients with ICU lengths of stay 30 days and greater: a seven-year retrospective study.

INTRODUCTION: Prolonged intensive care unit lengths of stay (ICU LOS) for critical illness can have acceptable mortality rates and quality of life despite significant costs. Only a few studies have specifically addressed prolonged ICU LOS after trauma. Our goals were to examine characteristics and outcomes of trauma patients with LOS >or= 30 days, predictors of prolonged stay and mortality. METHODS: All trauma ICU admissions over a seven-year period in a level 1 trauma center were analyzed. Admission characteristics, pre-existing conditions and acquired complications in the ICU were recorded. Logistic regression was used to identify independent predictors of prolonged LOS and predictors of mortality among those with prolonged LOS after univariate analyses. RESULTS: Of 4920 ICU admissions, 205 (4%) had ICU LOS >30 days. These patients were older and more severely injured. Age and injury severity score (ISS) were associated with prolonged LOS. After logistic regression analysis, sepsis, acute respiratory distress syndrome, and several infectious complications were important independent predictors of prolonged LOS. Within the group with ICU LOS >30 days, predictors of mortality were age, pre-existing renal disease as well as the development of renal failure requiring dialysis. Overall mortality was 12%. CONCLUSIONS: The majority of patients with ICU LOS >or= 30 days will survive their hospitalization. Infectious and pulmonary complications were predictors of prolonged stay. Further efforts targeting prevention of these complications are warranted.

Case report: unilateral negative pressure pulmonary edema - a complication of endobronchial intubation.

PURPOSE: We describe an unusual presentation of a case of fulminant unilateral pulmonary edema caused by unrecognized right endobronchial intubation that occurred during patient movement at the end of surgery. We review factors which may predispose to this complication. CLINICAL FEATURES: During emergence from anesthesia at the conclusion of bariatric surgery, a 27-yr-old patient (163 kg, body mass index 61.5 kg.m(-2)) became hypoxemic despite vigorous spontaneous ventilatory efforts through a 7.0 mm endotracheal tube with 100% oxygen. Right mainstem endobronchial tube malposition was detected by auscultation. The tube was repositioned, followed by copious pink frothy pulmonary edema abruptly issuing from the tracheal tube. Chest radiography revealed dense left lung infiltrates, consistent with unilateral negative pressure pulmonary edema, caused by brief, but forceful, inspiratory efforts against an obstructed left bronchus. This condition resolved over the following 24 hr. The patient's trachea was then extubated, and the remainder of her recovery was unremarkable. CONCLUSIONS: A high degree of airway anatomic variation, common tracheal tube insertion practices, unreliability of tube position detection methods, and the effects of patient positioning may all contribute to endotracheal tube malposition, including partial endobronchial intubation. Several modifications in airway management may help to prevent such complications of tracheal tube malposition.

Determinants of parathyroid hormone levels in nursing home residents.

INTRODUCTION: Elevated parathyroid hormone (PTH) levels contribute to age-related bone loss. Practitioners should be aware of iatrogenic and/or correctable determinants of PTH elevation. METHODS: We performed a cross-sectional study including 302 of 609 eligible residents at a state veterans home. Multiple regression analysis was used to determine the effect of 25-OH-D level, glomerular filtration rate (GFR), calcium supplements, diuretics, and mobility status on PTH levels. The dose of calcium carbonate and diuretics was determined as milligram per kilogram of body weight. RESULTS: The multiple regression process identified GFR, 25-OH-D level, as well as the dose of furosemide and calcium per kilogram of body weight as significant contributors to PTH. In a 70-kg resident, a daily dose of 40 mg of furosemide was associated with an increase of 22.8 pg/mL in PTH, while 500 mg of elemental calcium carbonate (in the absence of a proton pump inhibitor) was associated with a decrease of 8.7 pg/mL in PTH. An increase of 10 ng/mL in 25-OH-D was associated with a decrease of 5.7 pg/mL in PTH. DISCUSSION: Clinicians should be aware of the adverse effects of loop diuretics on urinary calcium excretion and PTH levels. Residents who ingest furosemide should be targeted to receive recommended doses of vitamin D and calcium.

Determinants of vitamin D levels in nursing home residents.

OBJECTIVE: To determine the effect of various doses of vitamin D(2) and D(3), as well as ambulatory status (a surrogate for sun exposure), on 25-OH-D levels. DESIGN: Cross-sectional study with multiple regression analysis. SETTING: A state veterans home for veterans and their spouses. PARTICIPANTS: Three hundred two of 609 eligible residents. MEASUREMENTS: Serum 25-OH-D and parathyroid hormone (PTH) level, supplemental dose of vitamins D(2) and D(3) per kilogram of body weight, and 3 levels of ambulatory status. RESULTS: The mean 25-OH-D level was 28.6 + 9.2 ng/mL; 6.6% of subjects had values of 16 ng/mL or below. Thirty-two percent of participants had 25-OH-D levels below 30 ng/mL and PTH elevation based on stage of kidney disease, evidence that the suboptimal 25-OH-D level had physiologic consequences. Residents unable to transfer independently had 25-OH-D levels 1.6 ng/mL lower than those able to transfer independently. A regression analysis performed in residents unable to transfer independently (less likely to be exposed to the sun) demonstrated that the average increase in 25-OH-D level per 100 IU of D(3) in a 70-kg resident was 2.1 ng/mL versus 1.8 ng/mL for vitamin D(2). CONCLUSION: Nursing home residents should receive at least 800-1000 IU of D(3) per day in an effort to maintain optimal vitamin D levels.

Comparison of outcomes using 2 delivery models of anticoagulation care.

BACKGROUND: Studies demonstrate the effectiveness of anticoagulation management service (AMS) in providing antithrombotic therapy for eligible patients. We sought to extend this concept by determining whether an interim telephone model (IT) is comparable to our current AMS model at achieving optimal therapeutic outcomes. METHODS: The 36-month trial (24-month study plus 12-month extension) enrolled 192 eligible patients receiving long-term warfarin therapy at a Veterans Affairs hospital. Consenting participants were randomly assigned to either our current face-to-face clinic model (AMS), or our IT model. The primary outcome was the percentage of time individuals' international normalized ratios (INRs) were maintained within their target INR range (2.0-3.0 or 2.5-3.5). Secondary outcomes included the number of adverse events (eg, thromboembolism or hemorrhage) experienced during the study. RESULTS: We found no statistically significant difference between the 2 groups in the percentage of time maintained within INR target range overall (55.1% for AMS; 57.8% for IT; P = .28) nor over the course of the study. There were no statistically significant differences in the rate of thromboembolic or serious bleeding events between IT and AMS participants. Nevertheless, we did note differences related to intensity of anticoagulation. The IT group receiving treatment at a higher intensity (INR, 2.5-3.5) experienced greater anticoagulation control (P = .04) and fewer complications than the AMS group. The IT participants, however, reported a significantly higher rate of minor bleeding events, experienced mainly by those at an INR range of 2.0 to 3.0. CONCLUSION: Our IT model is a viable modification of our AMS model for the management of patients undergoing chronic anticoagulant therapy.

Clustering of multiple endemic strains of methicillin-resistant Staphylococcus aureus in a nursing home: an 8-year study.

PFGE was performed on residents' first clinical MRSA isolate (n=94) during 8 years. Sixty-one percent of the isolates were clustered in time (P < .05) and space (P < .05) (i.e., 2 separate statistically significant tests). Isolates from individual units were genetically related, with only the occasional unrelated isolate.

Risk of acquiring influenza A in a nursing home from a culture-positive roommate.

Influenza A was cultured in 62 double rooms. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (CI95, 1.61-5.78) of acquiring influenza.

Alcohol use and cognition at mid-life: the importance of adjusting for baseline cognitive ability and educational attainment.

BACKGROUND: The nature of the relationship between cognition and alcohol consumption remains controversial. Studies have reported negative, positive, and nonsignificant effects of alcohol consumption on cognition. Problematic throughout the literature is that baseline cognitive ability has not been adequately controlled in previous studies, and even educational attainment is only sometimes controlled. Because such variables may be associated with both alcohol intake and later-life cognition, we hypothesize that the observed relationship between alcohol intake and cognition may change when these variables or other conditions in early life have been controlled. METHODS: We examined the relationship of alcohol intake and cognition at age 53 using the Wisconsin Longitudinal Study, which has followed Wisconsin high school graduates from 1957 to 1992. Our measures include cognitive ability test scores from the freshman and junior years of high school, educational attainment, an abstract reasoning test score at age 53, alcohol intake at age 53, and other measures. RESULTS: When no controls were used, both men and women with low levels of alcohol consumption at 53 (i.e., 0-1 drink per day) had better scores on the abstract reasoning subtest of the Wechsler Adult Intelligence Scale (WAIS-R) at age 53 than subjects who never drank or currently did not drink. However, after adjusting for adolescent-measured cognitive ability and educational attainment, men with low levels of consumption no longer had higher abstract reasoning scores than nondrinking men, but they still did have higher abstract reasoning scores than men who drank more than one drink per day. For women, adjusting for cognitive ability and educational attainment eliminated all significant effects of alcohol on cognition, and reversed the nonsignificant result that women with higher consumption had the highest cognition scores. These results demonstrate the importance of adjusting for baseline cognitive ability when attempting to study the effect of long-term alcohol use patterns on cognition, and that educational attainment cannot be considered a valid substitute for baseline cognition scores. CONCLUSIONS: Much of the apparent benefit of moderate alcohol intake on cognition in our society may well be explained by differential rates of alcohol consumption among subjects with differing baseline cognitive ability scores. Neither is there evidence that moderate alcohol intake reduces cognitive functioning.