MUC1 inhibition leads to decrease in PD-L1 levels via upregulation of miRNAs.

The PD-L1/PD-1 pathway is a critical component of the immunosuppressive tumor microenvironment in acute myeloid leukemia (AML), but little is known about its regulation. We investigated the role of the MUC1 oncoprotein in modulating PD-L1 expression in AML. Silencing of MUC1 in AML cell lines suppressed PD-L1 expression without a decrease in PD-L1 mRNA levels, suggesting a post-transcriptional mechanism of regulation. We identified the microRNAs miR-200c and miR-34a as key regulators of PD-L1 expression in AML. Silencing of MUC1 in AML cells led to a marked increase in miR-200c and miR-34a levels, without changes in precursor microRNA, suggesting that MUC1 might regulate microRNA-processing. MUC1 signaling decreased the expression of the microRNA-processing protein DICER, via the suppression of c-Jun activity. NanoString (Seattle, WA, USA) array of MUC1-silenced AML cells demonstrated an increase in the majority of probed microRNAs. In an immunocompetent murine AML model, targeting of MUC1 led to a significant increase in leukemia-specific T cells. In concert, targeting MUC1 signaling in human AML cells resulted in enhanced sensitivity to T-cell-mediated lysis. These findings suggest MUC1 is a critical regulator of PD-L1 expression via its effects on microRNA levels and represents a potential therapeutic target to enhance anti-tumor immunity.

Patient-derived xenotransplants can recapitulate the genetic driver landscape of acute leukemias.

Genomic studies have identified recurrent somatic mutations in acute leukemias. However, current murine models do not sufficiently encompass the genomic complexity of human leukemias. To develop preclinical models, we transplanted 160 samples from patients with acute leukemia (acute myeloid leukemia, mixed lineage leukemia, B-cell acute lymphoblastic leukemia, T-cell ALL) into immunodeficient mice. Of these, 119 engrafted with expected immunophenotype. Targeted sequencing of 374 genes and 265 frequently rearranged RNAs detected recurrent and novel genetic lesions in 48 paired primary tumor (PT) and patient-derived xenotransplant (PDX) samples. Overall, the frequencies of 274 somatic variant alleles correlated between PT and PDX samples, although the data were highly variable for variant alleles present at 0-10%. Seventeen percent of variant alleles were detected in either PT or PDX samples only. Based on variant allele frequency changes, 24 PT-PDX pairs were classified as concordant while the other 24 pairs showed various degree of clonal discordance. There was no correlation of clonal concordance with clinical parameters of diseases. Significantly more bone marrow samples than peripheral blood samples engrafted discordantly. These data demonstrate the utility of developing PDX banks for modeling human leukemia, and emphasize the importance of genomic profiling of PDX and patient samples to ensure concordance before performing mechanistic or therapeutic studies.

Active commuting reduces sociodemographic differences in adherence to recommendations derived from leisure-time physical activity among Brazilian adults.

OBJECTIVE: To investigate the consequences of including active commuting, compared with the leisure domain only, in the prevalence and sociodemographic factors associated with attending the physical activity recommendations, in Brazilian adults. STUDY DESIGN: Population-based cross-sectional study. METHOD: Adults between 20 and 59 years of age (n = 1720) were face-to-face interviewed from September 2009 to January 2010. Sociodemographic indicators and leisure-time and commuting physical activity were assessed by a validated questionnaire. Poisson regression was used to estimate crude and adjusted prevalence ratio (PR) and 95% confidence interval (95% CI). RESULTS: The prevalence of adherence to recommendations when only leisure-time physical activity was considered was 15.5% (95% CI: 13.6; 17.4) and was associated with men (PR: 1.57, 95% CI: 1.25; 1.96), adults without a partner (PR: 1.38 95% CI: 1.05; 1.81) and higher educational level and income. The prevalence of adherence to physical activity recommendations after the combination of leisure-time and commuting was 29.1% (95% CI: 26.5; 31.6). Percentages differences in favor of men, white adults and those with higher educational level and income were no longer significant after the inclusion of active commuting. CONCLUSION: The inclusion of active commuting expands the percentage of adults who achieved the health-related physical activity recommendations and reduced important sociodemographic differences derived from the analysis of leisure-time physical activity alone. Public health strategies should consider the different domains of physical activity in the monitoring and promotion of a more active lifestyle.

Barriers associated with frequency of leisure-time physical activity among Brazilian adults of different income strata.

This study aimed to estimate the prevalence of the main perceived barriers to leisure-time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of industrial workers from Brazil (n = 47,477), according to their income strata (low income: ≤$US280, middle income: $US281-$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low- (15.8%) and middle-income strata (18.2%) than among the individuals of the high-income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA.

Clustering of physical inactivity in leisure, work, commuting and household domains among Brazilian adults.

OBJECTIVES: To identify the clustering of physical inactivity in leisure, work, commuting and household contexts, and the sociodemographic factors associated with the clustering of inactive behaviour in different domains among Brazilian adults. STUDY DESIGN: Cross-sectional population-based study. METHODS: The study was performed in Florianopolis, capital of Santa Catarina, one of the southern states of Brazil, from September 2009 to January 2010. Adults aged 20-59 years were interviewed. Physical inactivity in each domain was defined as non-participation in specific physical activities, using a validated Brazilian questionnaire. Clustering of physical inactivity was identified by the ratio between observed prevalence and expected prevalence of 16 different combinations. Multinomial logistic regression was used in the analysis of sociodemographic factors associated with clustering of physical inactivity. RESULTS: Of the 1720 interviewees, the greatest differences between the observed and expected proportions were observed in simultaneous physical inactivity in the leisure and household domains for men, and physical inactivity in the leisure domain alone for women (59% and 88%, respectively); these differences were higher than expected if the behaviours were independent. Physical inactivity in two or more domains was observed more frequently in men and in individuals with a higher per-capita family income. Ageing was associated with physical inactivity in three or four domains. CONCLUSIONS: Physical inactivity was observed in different domains according to gender. Men and older individuals with a higher per-capita family income were more likely to exhibit physical inactivity when all domains were considered together.

Effect of simulated leg length discrepancy on plantar pressure distribution in diabetic patients with neuropathic foot ulceration.

OBJECTIVE: To study the effect of a minor degree of artificially induced leg length discrepancy (LLD) on plantar pressure distribution in diabetic patients with neuropathic foot ulceration. METHOD: In-shoe plantar pressure distributions were measured on the ulcerated foot during walking using F-scan (Tekscan Inc.). To simulate minor LLD, the contralateral leg length was changed by asking patients to walk under three different conditions: wearing shoe of the same sole thickness (NLLD), walking with a bare foot (20mm long leg) and wearing a 40mm-high platform-sole shoe (20mm short leg). These three different walking conditions were compared in a randomised, single-blinded crossover design. RESULTS: The study included 28 diabetic patients with neuropathic foot ulcers (53.7 ± 6.8 years; 16 males, 12 female). Notably, the peak pressure and pressure time integral (PTI) were the most affected parameters. PTI significantly increased beneath total foot, mid-foot, 2nd, 3rd, 4th and 5th metatarsal heads (MTHs), and 3rd toe, when the 20mm short leg was simulated (79.4 ± 21.1; 61.5 ± 32.3; 59.9 ± 36.5; 69 ± 42.1; 70.6 ± 42.3; 63.9 ± 33.7; 40.± 33.2 kPa·s, respectively), compared with NLLD (73.7 ± 19.9; 55.524; 51.8 ± 30.1; 58.4 ± 37.6; 60.3 ± 39.5; 57.2 ± 32.3; 36.9 ± 33.3 kPa·s, respectively). CONCLUSION: The short leg of diabetic patients with neuropathic foot ulcers will be subjected to greater pressure load, primarily beneath the total foot, mid-foot and 2nd, 3rd, 4th and 5th metatarsal heads. As such, care should be taken to avoid minor LLD, as it could inadvertently develop on using offloading devices. DECLARATION OF INTEREST: The authors have nothing to declare.

Risk factors of hyperparathyroidism in advanced stages of chronic kidney disease.

The pathogenesis of renal osteodystrophy is not clearly defined. We evaluate in this study the potential effect of demographic and biochemical markers on parathormone (PTH) level in patients with chronic kidney disease (CKD) stages 4 and 5. We retrospectively studied 138 patients with CKD stages 4 and 5 selected from the database of the Sheffield Kidney Institute in the interval from 1996 to 2005. All patients had baseline as well as follow-up levels of PTH, adjusted serum calcium, phosphate, calcium phosphorus product, albumin, bicarbonate and estimated glomerular filtration rate (eGFR). At baseline, serum albumin, eGFR and adjusted serum calcium levels significantly negatively correlated with PTH serum levels. Adjusted serum calcium levels at last follow-up remained a significant negative predictor of PTH levels; however, baseline PTH levels demonstrated a significant positive correlation with final serum PTH levels. This study high lights the significance of serum PTH levels at presentation on the long-term effect of parathyroid gland function. This reinforces the need for early intervention to achieve optimal control of hyperparathyroidism in CKD patients.

Conservatively managed patients with stage 5 chronic kidney disease--outcomes from a single center experience.

BACKGROUND: Limited survival data are available on chronic kidney disease stage 5 (CKD 5) patients who opt for conservative management rather than dialysis. AIM: To measure survival in such patients and investigate potential factors predicting survival. DESIGN: Retrospective survival analysis of a cohort of conservatively managed CKD 5 patients from a single center. METHODS: Survival was measured in 69 conservatively managed patients from the time they were first known to have CKD 5. Comorbidities, residual renal function and other laboratory parameters (calcium, phosphate, parathyroid hormone, albumin and hemoglobin) and blood pressure were recorded. RESULTS: Overall median patient survival from the time of first known CKD 5 was 21 months. Patients known to a nephrologist before reaching CKD 5 survived longer (median 32 months) than those presenting with CKD 5 (15 months, P = 0.025). Serum albumin >35 g/l was associated with greater survival, but other biochemical parameters, comorbidity grade and age did not predict survival. CONCLUSION: These survival data provide useful information for nephrologists counseling CKD 5 patients considering whether to pursue dialysis or conservative management. Risk factors that correlate with survival in the dialysis population may not predict survival in conservatively managed CKD 5 patients.

The impact of topical phenytoin on recalcitrant neuropathic diabetic foot ulceration.

OBJECTIVE: To study the impact of topical phenytoin on the healing of recalcitrant neuropathic diabetic foot ulcers in patients with no clinical evidence of ischaemia or infection, and to evaluate its antibacterial effect. METHOD: Thirty-two patients were enrolled into the study. Topical phenytoin in the form of 2% aerosol powder was applied once daily in addition to the patient's usual treatment (weekly sharp debridement, offloading and use of a gauze dressing) for eight weeks. The primary outcome was change in ulcer area over time, measured by grid tracing. Secondary outcomes were the ability of topical phenytoin to eradicate bacterial isolates, and the occurrence of adverse events. RESULTS: Topical phenytoin significantly improved healing of recalcitrant neuropathic diabetic foot ulcers. Baseline wound area was 319.3 + 340.4 mm2, reducing to 286.1 + 341.1 mm2 and 269.1 + 341.2 mm2 after four and eight weeks respectively. However, the overall reduction in ulcer size was only 18.3% + 27.5% and 25.7% + 38.6 % respectively. Topical phenytoin therapy over eight weeks did not eradicate any of the bacterial wound isolates (Staphylococcus spp., Proteus spp. or Pseudomonas spp.). Of the 32 patients evaluated, only eight (25%) achieved more than 50% reduction in ulcer size after eight weeks of treatment. CONCLUSION: Topical phenytoin can enhance wound healing in recalcitrant neuropathic diabetic foot ulcers, although only one-quarter of patients achieved more than 50% reduction in ulcer size after eight weeks of therapy. Further research is needed to characterise those patients who will satisfactorily respond to such therapy.

C-K-D: more vascular damage than kidney disease.

The perceived prevalence of Chronic kidney disease (CKD) is on the increase worldwide. This has led to considerable debate and controversy as some believe such an increase reflects a genuine increase in the incidence and prevalence of CKD whilst others perceive it to be the result of the ageing of the population with the inherent decline in kidney function associated with advancing age. This review tries to reconcile both views drawing attention to the fact that the age-related decline in kidney function may not be physiological but instead a manifestation of diffuse vascular ageing and atherosclerosis affecting a number of endorgans including the kidneys. Consequently, the so-call age-related chronic kidney disease (CKD) may be better defined as Cardio-Kidney-Damage (C-K-D).

The management of CKD: a look into the future.

The increasing global prevalence of chronic kidney disease (CKD) and end-stage renal disease with the associated spiraling cost has profound public health and economic implications. This has made slowing the progression of CKD, a major health-care priority. CKD is invariably characterized by progressive kidney fibrosis and at present, treatment aiming to slow the progression of CKD is limited to aggressive blood pressure control, with few therapies targeting the fibrotic process itself. In this review, we explore the potential of experimental therapeutic strategies, based on preventing or reversing the pathophysiologic steps of kidney remodeling that lead to fibrosis.

Chronic kidney disease as a global public health problem: approaches and initiatives - a position statement from Kidney Disease Improving Global Outcomes.

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. There is now convincing evidence that CKD can be detected using simple laboratory tests, and that treatment can prevent or delay complications of decreased kidney function, slow the progression of kidney disease, and reduce the risk of cardiovascular disease (CVD). Translating these advances to simple and applicable public health measures must be adopted as a goal worldwide. Understanding the relationship between CKD and other chronic diseases is important to developing a public health policy to improve outcomes. The 2004 Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on 'Definition and Classification of Chronic Kidney Disease' represented an important endorsement of the Kidney Disease Outcome Quality Initiative definition and classification of CKD by the international community. The 2006 KDIGO Controversies Conference on CKD was convened to consider six major topics: (1) CKD classification, (2) CKD screening and surveillance, (3) public policy for CKD, (4) CVD and CVD risk factors as risk factors for development and progression of CKD, (5) association of CKD with chronic infections, and (6) association of CKD with cancer. This report contains the recommendations from the meeting. It has been reviewed by the conference participants and approved as position statement by the KDIGO Board of Directors. KDIGO will work in collaboration with international and national public health organizations to facilitate implementation of these recommendations.

Folding and catalysis of the hairpin ribozyme.

The active form of the hairpin ribozyme is brought about by the interaction of two formally unpaired loops. In a natural molecule, these are present on two adjacent arms of a four-way junction. Although activity can be obtained in molecules lacking this junction, the junction is important in the promotion of the folded state of the ribozyme under physiological conditions, at a rate that is faster than the chemical reaction. Single-molecule fluorescence resonance energy transfer studies show that the junction introduces a discrete intermediate into the folding process, which repeatedly juxtaposes the two loops and thus promotes their docking. Using single-molecule enzymology, the cleavage and ligation rates have been measured directly. The pH dependence of the rates is consistent with a role for nucleobases acting in general acid-base catalysis.

Single-molecule studies of DNA and RNA four-way junctions.

Branched helical junctions are common in nucleic acids. In DNA, the four-way junction (Holliday junction) is an essential intermediate in homologous recombination and is a highly dynamic structure, capable of stacking conformer transitions and branch migration. Our single-molecule fluorescence studies provide unique insight into the energy landscape of Holliday junctions by visualizing these processes directly. In the hairpin ribozyme, an RNA four-way junction is an important structural element that enhances active-site formation by several orders of magnitude. Our single-molecule studies suggest a plausible mechanism for how the junction achieves this remarkable feat; the structural dynamics of the four-way junction bring about frequent contacts between the loops that are needed to form the active site. The most definitive evidence for this is the observation of three-state folding in single-hairpin ribozymes, the intermediate state of which is populated due to the intrinsic properties of the junction.

Meals, snacks and food choices in Brazilian shift workers with high energy expenditure.

OBJECTIVE: To describe the food intake of garbage collectors, who works in three shifts, in terms of meal and snack frequency, content, time distribution and the contribution of various popular foods to the total diet. METHODS: Sixty-six Brazilian garbage collectors, who work in morning, afternoon, and night shift, participated in the present study. The quantitative methods used were a combination of one 24-h recall and two 24-h records during three nonconsecutive work days. The qualitative method used was the food-based classification of eating episodes model modified in order to define meals or snacks in three categories of events: meals with three food groups of high nutrient density (three HND meals), meals with two food groups of high nutrient density (two HND meals) and snacks, composed of only one food category of high nutrient density. RESULTS: The total number of eating events per day was significantly higher for night shift workers. Over 24-h, 'two HND meals' were the most common events and contributed the most energy, in all three shifts. Night shift workers ate more at dawn and less in the morning than other shifts. In all three shifts, meat was the most important food contributing to energy intake. CONCLUSION: Different work schedules did not affect the relative frequency of meal types and snacks or their contribution to daily energy intake, but affected the daily distribution of eating events, with a redistribution of intake from day to night in night shift workers.