Showing papers by "David W. Johnson published in 2006"

Diagnosis and management of bronchiolitis

Abstract: Bronchiolitis is a disorder most commonly caused in infants by viral lower respiratory tract infection. It is the most common lower respiratory infection in this age group. It is characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm. The American Academy of Pediatrics convened a committee composed of primary care physicians and specialists in the fields of pulmonology, infectious disease, emergency medicine, epidemiology, and medical informatics. The committee partnered with the Agency for Healthcare Research and Quality and the RTI International-University of North Carolina Evidence-Based Practice Center to develop a comprehensive review of the evidence-based literature related to the diagnosis, management, and prevention of bronchiolitis. The resulting evidence report and other sources of data were used to formulate clinical practice guideline recommendations. This guideline addresses the diagnosis of bronchiolitis as well as various therapeutic interventions including bronchodilators, corticosteroids, antiviral and antibacterial agents, hydration, chest physiotherapy, and oxygen. Recommendations are made for prevention of respiratory syncytial virus infection with palivizumab and the control of nosocomial spread of infection. Decisions were made on the basis of a systematic grading of the quality of evidence and strength of recommendation. The clinical practice guideline underwent comprehensive peer review before it was approved by the American Academy of Pediatrics. This clinical practice guideline is not intended as a sole source of guidance in the management of children with bronchiolitis. Rather, it is intended to assist clinicians in decision-making. It is not intended to replace clinical judgment or establish a protocol for the care of all children with this condition. These recommendations may not provide the only appropriate approach to the management of children with bronchiolitis.

Guidelines for colonoscopy surveillance after polypectomy: A consensus update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society

Abstract: Adenomatous polyps are the most common neoplastic findings uncovered in people who undergo colorectal screening or have a diagnostic workup for symptoms. It was common practice in the 1970s for these patients to have annual follow-up surveillance examinations to detect additional new adenomas as well as missed synchronous adenomas. As a result of the National Polyp Study report in 1993, which demonstrated clearly in a randomized design that the first postpolypectomy examination could be deferred for 3 years, guidelines published by a gastrointestinal consortium in 1997 recommended that the first follow-up surveillance be 3 years after polypectomy for most patients. In 2003, these guidelines were updated, colonoscopy was recommended as the only follow-up examination, and stratification at baseline into lower and higher risk for subsequent adenomas was suggested. The 1997 and 2003 guidelines dealt with both screening and surveillance. However, it has become increasingly clear that postpolypectomy surveillance is now a large part of endoscopic practice, draining resources from screening and diagnosis. In addition, surveys have demonstrated that a large proportion of endoscopists are conducting surveillance examinations at shorter intervals than recommended in the guidelines. In the present paper, a careful analytic approach was designed addressing all evidence available in the literature to delineate predictors of advanced pathology, both cancer and advanced adenomas, so that patients can be more definitely stratified at their baseline colonoscopy into those at lower or increased risk for a subsequent advanced neoplasia. People at increased risk have either three or more adenomas, or high-grade dysplasia, or villous features, or an adenoma ≥1 cm in size. It is recommended that they have a 3-year follow-up colonoscopy. People at lower risk who have one or two small (<1 cm) tubular adenomas with no high-grade dysplasia can have a follow up in 5 to 10 years, whereas people with hyperplastic polyps only should have a 10-year follow up as average-risk people. Recent papers have reported a significant number of missed cancers by colonoscopy. However, high-quality baseline colonoscopy with excellent patient preparation and adequate withdrawal time should minimize this and reduce clinicians' concerns. These guidelines were developed jointly by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society to provide a broader consensus and thereby increase utilization of the recommendations by endoscopists. Adoption of these guidelines nationally can have a dramatic impact on shifting available resources from intensive surveillance to screening. It has been shown that the first screening colonoscopy and polypectomy produces the greatest effects on reducing the incidence of colorectal cancer in patients with adenomatous polyps.

Tolevamer, a Novel Nonantibiotic Polymer, Compared with Vancomycin in the Treatment of Mild to Moderately Severe Clostridium difficile–Associated Diarrhea

Abstract: BACKGROUND Current antibiotic therapies for Clostridium difficile-associated diarrhea have limitations, including progression to severe disease, recurrent C. difficile-associated diarrhea, and selection for nosocomial pathogens. Tolevamer, a soluble, high-molecular weight, anionic polymer that binds C. difficile toxins A and B is a unique nonantibiotic treatment option. METHODS In this 3-arm, multicenter, randomized, double-blind, active-controlled, parallel-design phase II study, patients with mild to moderately severe C. difficile-associated diarrhea were randomized to receive 3 g of tolevamer per day (n = 97), 6 g of tolevamer per day (n = 95), or 500 mg of vancomycin per day (n = 97). The primary efficacy parameter was time to resolution of diarrhea, defined as the first day of 2 consecutive days when the patient had hard or formed stools (any number) or < or = 2 stools of loose or watery consistency. RESULTS In the per-protocol study population, resolution of diarrhea was achieved in 48 (67%) of 72 patients receiving 3 g of tolevamer per day (median time to resolution of diarrhea, 4.0 days; 95% confidence interval, 2.0-6.0 days), in 58 (83%) of 70 patients receiving 6 g of tolevamer per day (median time to resolution of diarrhea, 2.5 days; 95% confidence interval, 2.0-3.0 days), and in 73 (91%) of 80 patients receiving vancomycin (median time to resolution of diarrhea, 2.0 days; 95% confidence interval, 1.0-3.0 days). Tolevamer administered at a dosage of 6 g per day was found to be noninferior to vancomycin administered at a dosage of 500 mg per day with regard to time to resolution of diarrhea (P = .02) and was associated with a trend toward a lower recurrence rate. Tolevamer was well tolerated but was associated with an increased risk of hypokalemia. CONCLUSIONS Tolevamer, a novel polystyrene binder of C. difficile toxins A and B, effectively treats mild to moderate C. difficile diarrhea and merits further clinical development.

Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and US Multi-Society Task Force on Colorectal Cancer.

Abstract: Patients with resected colorectal cancer are at risk for recurrent cancer and metachronous neoplasms in the colon. This joint update of guidelines by the American Cancer Society (ACS) and US Multi-Society Task Force on Colorectal Cancer addresses only the use of endoscopy in the surveillance of these patients. Patients with endoscopically resected Stage I colorectal cancer, surgically resected Stage II and III cancers, and Stage IV cancer resected for cure (isolated hepatic or pulmonary metastasis) are candidates for endoscopic surveillance. The colorectum should be carefully cleared of synchronous neoplasia in the perioperative period. In nonobstructed colons, colonoscopy should be performed preoperatively. In obstructed colons, double contrast barium enema or computed tomography colonography should be done preoperatively, and colonoscopy should be performed 3 to 6 months after surgery. These steps complete the process of clearing synchronous disease. After clearing for synchronous disease, another colonoscopy should be performed in 1 year to look for metachronous lesions. This recommendation is based on reports of a high incidence of apparently metachronous second cancers in the first 2 years after resection. If the examination at 1 year is normal, then the interval before the next subsequent examination should be 3 years. If that colonoscopy is normal, then the interval before the next subsequent examination should be 5 years. Shorter intervals may be indicated by associated adenoma findings (see Postpolypectomy Surveillance Guideline). Shorter intervals are also indicated if the patient's age, family history, or tumor testing indicate definite or probable hereditary nonpolyposis colorectal cancer. Patients undergoing low anterior resection of rectal cancer generally have higher rates of local cancer recurrence, compared with those with colon cancer. Although effectiveness is not proven, performance of endoscopic ultrasound or flexible sigmoidoscopy at 3- to 6-month intervals for the first 2 years after resection can be considered for the purpose of detecting a surgically curable recurrence of the original rectal cancer.

Somali and Oromo refugee women: trauma and associated factors.

Abstract: This paper reports a study identifying the demographic characteristics self-reported trauma and torture prevalence and association of trauma experience and health and social problems among Somali and Oromo women refugees. Nearly all refugees have experienced losses and many have suffered multiple traumatic experiences including torture. Their vulnerability to isolation is exacerbated by poverty grief and lack of education literacy and skills in the language of the receiving country. Using data from a cross-sectional population-based survey conducted from July 1999 to September 2001 with 1134 Somali and Oromo refugees living in the United States of America a sub-sample of female participants with clearly identified parenting status (n = 458) were analysed. Measures included demographics history of trauma and torture scales for physical psychological and social problems and a post-traumatic stress symptom checklist. Results indicated high overall trauma and torture exposure and associated physical social and psychological problems. Women with large families reported statistically significantly higher counts of reported trauma (mean 30 P < 0.001) and torture (mean 3 P < 0.001) and more associated problems (P < 0.001) than the other two groups. Women who reported higher levels of trauma and torture were also older (P < 0.001) had more family responsibilities had less formal education (P < 0.001) and were less likely to speak English (P < 0.001). These findings suggest a need for nurses and especially public health nurses who work with refugee and immigrant populations in the community to develop a more comprehensive understanding of the range of refugee womens experiences and the continuum of needs post-migration particularly among older women with large family responsibilities. Nurses with their holistic framework are ideally suited to partner with refugee women to expand their health agenda beyond the biomedical model to promote healing and reconnection with families and communities. (authors)

Quality of Life for Children and Adolescents: Impact of HIV Infection and Antiretroviral Treatment

Abstract: BACKGROUND. HIV/AIDS mortality rates in the United States are declining; pediatric HIV has become a chronic disease, with quality of life (QoL) outcomes assuming greater importance. OBJECTIVES. To compare QoL among HIV-infected and uninfected children and to assess the impact of different antiretroviral regimens on QoL among HIV-infected children. METHODS. Perinatally exposed, HIV-infected (N = 1847) and uninfected (N = 712) children and adolescents were studied. Among infected children, 1283 were available for the antiretroviral regimen analysis. QoL domain scores were assessed for subjects 6 months to 4 years, 5 to 11 years, and 12 to 21 years of age, and the impact of infection status and alternative treatment regimens on QoL domains was evaluated. RESULTS. HIV infection was associated with significantly worse mean adjusted scores for functional status among children 6 months to 4 years of age and health perceptions, physical resilience, physical functioning, and social/role functioning among those 5 to 11 years of age. However, uninfected children 5 to 11 years of age reported significantly worse psychological functioning. HIV-infected children (5–11 years of age) and adolescents (12–21 years of age) receiving no antiretroviral treatment had worse health perceptions. Adolescents receiving no antiretroviral agents also had worse symptoms. When antiretroviral regimens were compared, adolescents receiving protease inhibitor plus nonnucleoside reverse transcriptase inhibitor-containing therapy had worse symptoms, compared with those receiving protease inhibitor-containing therapy; otherwise, no significant differences were found. CONCLUSIONS. Generally parents of HIV-infected children 6 months to 4 years and 5 to 11 years of age generally reported lower mean QoL scores than did parents of uninfected children, although worse psychological functioning was reported for uninfected children. HIV-infected adolescents not receiving antiretroviral treatment had worse health perceptions and symptoms. We found no consistent QoL differences among children receiving different antiretroviral regimens.

Prescribed Fire Effects on Forest Floor and Soil Nutrients in a Sierra Nevada Forest

Abstract: The objectives of this study were to quantify the effects of prescribed fire on forest floor C and nutrient content, soil chemical properties, and soil leaching in a Jeffrey pine (Pinus jeffreyi [Grev. and Balf.]) forest in the eastern Sierra Nevada Mountains of California. The study included a pres

Dietary protein restriction as a treatment for slowing chronic kidney disease progression: the case against.

Abstract: Low-protein diets (

A novel imaging technique to measure capillary-refill time: improving diagnostic accuracy for dehydration in young children with gastroenteritis.

Abstract: BACKGROUND. Assessment of dehydration in young children currently depends on clinical judgment, which is relatively inaccurate. By using digital videography, we developed a way to assess capillary-refill time more objectively. OBJECTIVE. Our goal was to determine whether digitally measured capillary-refill time assesses the presence of significant dehydration (≥5%) in young children with gastroenteritis more accurately than conventional capillary refill and overall clinical assessment. METHODS. We prospectively enrolled children with gastroenteritis,1 month to 5 years of age, who were evaluated in a tertiary-care pediatric emergency department and judged by a triage nurse to be at least mildly dehydrated. Before any treatment, we measured the weight and digitally measured capillary-refill time of these children. Pediatric emergency physicians determined capillary-refill time by using conventional methods and degree of dehydration by overall clinical assessment by using a 7-point Likert scale. Postillness weight gain was used to estimate fluid deficit; beginning 48 hours after assessment, children were reweighed every 24 hours until 2 sequential weights differed by no more than 2%. We compared the accuracy of digitally measured capillary-refill time with conventional capillary refill and overall clinical assessment by determining sensitivities, specificities, likelihood ratios, and area under the receiver operator characteristic curves. RESULTS. A total of 83 patients were enrolled and had complete follow-up; 13 of these patients had significant dehydration (≥5% of body weight). The area under the receiver operator characteristic curves for digitally measured capillary-refill time and overall clinical assessment relative to fluid deficit ( CONCLUSIONS. Results of this prospective cohort study suggest that digitally measured capillary-refill time more accurately predicts significant dehydration (≥5%) in young children with gastroenteritis than overall clinical assessment.

Effect of aggressive risk factor modification on cardiac events and myocardial ischaemia in patients with chronic kidney disease

Abstract: Objective: To examine whether aggressive risk factor modification in chronic kidney disease (CKD) can limit the development of new ischaemia or reduce cardiac events. Methods: Patients with CKD were randomly assigned to either an aggressive risk factor modification strategy (targeted treatment of hypertension, dyslipidaemia, homocysteine, haemoglobin and phosphate) or standard care. An intention to treat analysis was performed on 152 patients who had baseline dobutamine stress echocardiography (DSE), including 107 who had follow-up DSE. Biochemical parameters, cardiac risk factors and investigations (ECG, two-dimensional echocardiography) were recorded at baseline. New ischaemia was classed as new or worsening stress wall motion abnormality between follow-up and baseline DSE. Patients were followed up for the development of new ischaemia or cardiac death, acute coronary syndrome and non-fatal myocardial infarction over 1.8 years. Results: The development of new ischaemia was common but not different between the standard and aggressively treated groups (15 (21%) v 18 (23%), p = 0.8). Independent predictors of new ischaemia were older age, abnormal ECG, higher systolic blood pressure and lower serum high density lipoprotein cholesterol, but not treatment arm. The standard and aggressively treated groups did not differ in cardiac event rate (10% v 13%, p = 0.6) or all-cause mortality (10% v 19%, p = 0.2). In patients with an abnormal baseline DSE (non-diagnostic, scar or ischaemia), the event rate was similar (22% v 20%, p = 0.9). Conclusion: Aggressive risk factor modification in CKD does not limit the development of new ischaemia or reduce cardiac events in patients with an abnormal DSE.

Novel renoprotective actions of erythropoietin: new uses for an old hormone.

Abstract: Erythropoietin (EPO) has been used widely for the treatment of anaemia associated with chronic kidney disease and cancer chemotherapy for nearly 20 years. More recently, EPO has been found to interact with its receptor (EPO-R) expressed in a large variety of non-haematopoietic tissues to induce a range of cytoprotective cellular responses, including mitogenesis, angiogenesis, inhibition of apoptosis and promotion of vascular repair through mobilization of endothelial progenitor cells from the bone marrow. Administration of EPO or its analogue, darbepoetin, promotes impressive renoprotection in experimental ischaemic and toxic acute renal failure, as evidenced by suppressed tubular epithelial apoptosis, enhanced tubular epithelial proliferation and hastened functional recovery. This effect is still apparent when administration is delayed up to 6 h after the onset of injury and can be dissociated from its haematological effects. Based on these highly encouraging results, at least one large randomized controlled trial of EPO therapy in ischaemic acute renal failure is currently underway. Preliminary experimental and clinical evidence also indicates that EPO may be renoprotective in chronic kidney disease. The purpose of the present article is to review the renoprotective benefits of different protocols of EPO therapy in the settings of acute and chronic kidney failure and the potential mechanisms underpinning these renoprotective actions. Gaining further insight into the pleiotropic actions of EPO will hopefully eventuate in much-needed, novel therapeutic strategies for patients with kidney disease.

Pyrrolidine dithiocarbamate exerts anti-proliferative and pro-apoptotic effects in renal cell carcinoma cell lines

Abstract: Background. The activation of nuclear factor-kB (NF-kB) has been implicated in the development, progression and metastasis of renal cell carcinoma (RCC). This study investigates the effect of pyrrolidine dithiocarbamate (PDTC), a NF-kB inhibitor, on two metastatic human RCC cell lines, ACHN and SN12K1. Methods. RCC cell lines and normal cells were exposed to 25 or 50mM of PDTC. Apoptosis was measured by flow cytometry and TdT-mediated nick end labelling methods. Cell viability and proliferation were measured by MTT and BrdU assays, respectively. Expression of NF-kB subunits, IkBs, IkB Kinase (IKK) complex and apoptotic regulatory proteins were analysed by western blotting and/or immunofluorescence. DNA-binding activity of NF-kB subunits were measured by ELISA. Results. RCC cell lines had a higher basal level expression of all the five subunits of NF-kB than normal primary cultures of human proximal tubular epithelial cells or HK-2 cells. PDTC decreased the viability and proliferation of RCC, but not normal cells. Of the two RCC cell lines, ACHN had a higher basal level expression of all the five NF-kB subunits than SN12K1 and was more resistant to PDTC. While PDTC induced an overall decrease in expression of all the five NF-kB subunits in both RCC cell lines, unexpectedly, it increased the nuclear expression of NF-kB in ACHN, but not in SN12K1. PDTC reduced the DNA-binding activity of all the NF-kB subunits and the expression of the IKK complex (IKK-a, IKK-b and IKK-g) and the inhibitory units IkB-a and IkB-b. PDTC induced a significant increase in apoptosis in both RCC cell lines. This was associated with a decrease in expression of the anti-apoptotic proteins, Bcl-2 and Bcl-XL, without marked changes in the pro-apoptotic protein Bax. Conclusion. These data suggest that PDTC has the potential to be an anticancer agent in some forms of RCC.

Peace education for consensual peace: the essential role of conflict resolution 1

Abstract: Peace education is a key for establishing and maintaining a consensual peace. Creating an effective peace education program involves five steps. First, a public education system must be established with compulsory attendance; all children and youth should attend so that students from the previously conflicting groups interact and have the opportunity to build positive relationships with each other. Second, a sense of mutuality and common fate needs to be established that highlights mutual goals, the ‘just’ distribution of benefits from achieving the goals, and a common identity. In schools, this is primarily done through the use of cooperative learning. Third, students should be taught the constructive controversy procedure to ensure they know how to make difficult decisions and engage in political discourse. Fourth, students should be taught how to engage in integrative negotiations and peer mediation to resolve their conflicts with each other constructively. Finally, civic values should be inculcated th...

Dosing of gentamicin in patients with end-stage renal disease receiving hemodialysis.

Abstract: The aim of this study was to evaluate dosing schedules of gentamicin in patients with end-stage renal disease and receiving hemodialysis. Forty-six patients were recruited who received gentamicin while on hemodialysis. Each patient provided approximately 4 blood samples at various times before and after dialysis for analysis of plasma gentamicin concentrations. A population pharmacokinetic model was constructed using NONMEM (version 5). The clearance of gentamicin during dialysis was 4.69 L/h and between dialysis was 0.453 L/h. The clearance between dialysis was best described by residual creatinine clearance (as calculated using the Cockcroft and Gault equation), which probably reflects both lean mass and residual clearance mechanisms. Simulation from the final population model showed that predialysis dosing has a higher probability of achieving target maximum concentration (Cmax) concentrations (> 8 mg/L) within acceptable exposure limits (area under the concentration-time curve [AUC] values > 70 and < 120 mg x h/L per 24 hours) than postdialysis dosing.

Effect of previously failed kidney transplantation on peritoneal dialysis outcomes in the Australian and New Zealand patient populations

Abstract: Background. There is limited information about the outcomes of patients commencing peritoneal dialysis (PD) after failed kidney transplantation. The aim of the present study was to compare patient survival, death-censored technique survival and peritonitis-free survival between patients initiating PD after failed renal allografts and those after failed native kidneys. Methods. The study included all patients from the ANZDATA Registry who started PD between April 1, 1991 and March 31, 2004. Times to death, deathcensored technique failure and first peritonitis episode were examined by multivariate Cox proportional hazards models. For all outcomes, conditional risk set models were utilized for the multiple failure data, and analyses were stratified by failure order. Standard errors were calculated by using robust variance estimation for the cluster-correlated data. Results. In total, 13 947 episodes of PD were recorded in 23 579 person-years. Of these, 309 PD episodes were started after allograft failure. Compared with PD patients who had never undergone kidney transplantation, those with failed renal allografts were more likely to be younger, Caucasian, New Zealand residents and life-long non-smokers with lower body mass index (BMI), poorer initial renal function and a longer period from commencement of the first renal replacement therapy to PD. On multivariate analysis, PD patients with failed kidney transplants had comparable patient mortality [weighted hazards ratio (HR) 1.09, 95% confidence interval (CI) 0.81–1.45, P ¼ 0.582], death-censored technique failure (adjusted HR 0.91, 95% CI 0.75–1.10, P ¼ 0.315) and peritonitis-free survival (adjusted HR 0.92, 95% CI 0.72–1.16, P ¼ 0.444) with those PD patients who had failed native kidneys. Similar findings were observed in a subset of patients (n ¼ 5496) for whom peritoneal transport status was known and included in the models as a covariate. Conclusion. Patients commencing PD after renal allograft failure experienced outcomes comparable with those with failed native kidneys. PD appears to be a viable option for patients with failed kidney allografts.

Prevention of Progression of Kidney Disease

Abstract: SUMMARY OF THE EVIDENCE In summary, there is no convincing or conclusive evidencethat long-term protein restriction delays the progression ofCKD. The longest lasting, largest and best-designed RCT(MDRD study) argues against an important benefit. Fourmeta-analyses have demonstrated either a modest or sub-stantial benefit of protein-restricted diets, but three of theseused an inappropriate outcome measure (renal survival),which does not allow distinction between delay of dialysisdue to suppression of uraemic symptoms vs. slowing renalfailure progression. The only meta-analysis which used esti-mated GFR as an outcome measure found only a very weakbenefit of dietary protein restriction. It also found evidenceof possible publication bias favouring a beneficial effect oflow protein diets. The trials showed some heterogeneity andcannot substitute for properly conducted RCTs. Moreover,the possibility of a modest benefit of low-protein diets onrenal failure progression must be weighed against the risk ofa concomitant decline in nutritional parameters. Only threeof the 11 RCTs in non-diabetics have addressed the effect ofrestricted protein diets on nutrition

Effect of plasma shaping on performance in the National Spherical Torus Experiment

Abstract: The National Spherical Torus Experiment (NSTX) has explored the effects of shaping on plasma performance as determined by many diverse topics including the stability of global magnetohydrodynamic (MHD) modes (e.g., ideal external kinks and resistive wall modes), edge localized modes (ELMs), bootstrap current drive, divertor flux expansion, and heat transport. Improved shaping capability has been crucial to achieving βt∼40%. Precise plasma shape control has been achieved on NSTX using real-time equilibrium reconstruction. NSTX has simultaneously achieved elongation κ∼2.8 and triangularity δ∼0.8. Ideal MHD theory predicts increased stability at high values of shaping factor S≡q95Ip∕(aBt), which has been observed at large values of the S∼37[MA∕(m∙T)] on NSTX. The behavior of ELMs is observed to depend on plasma shape. A description of the ELM regimes attained as shape is varied will be presented. Increased shaping is predicted to increase the bootstrap fraction at fixed Ip. The achievement of strong shaping ...

Characterization of small, type v edge-localized modes in the national spherical torus experiment

Abstract: There has been a substantial international research effort in the fusion community to identify tokamak operating regimes with either small or no periodic bursts of particles and power from the edge plasma, known as edge-localized modes (ELMs). While several candidate regimes have been presented in the literature, very little has been published on the characteristics of the small ELMs themselves. One such small ELM regime, also known as the Type V ELM regime, was recently identified in the National Spherical Torus Experiment [M. Ono, S. M. Kaye, Y.-K. M. Peng et al., Nucl. Fusion 40, 557 (2000)]. In this paper, the spatial and temporal structure of the Type V ELMs is presented, as measured by several different diagnostics. The composite picture of the Type V ELM is of an instability with one or two filaments that rotate toroidally at ∼5–10km∕s, in the direction opposite to the plasma current and neutral beam injection. The toroidal extent of Type V ELMs is typically ∼5m, whereas the cross-field (radial) ex...

Cardiorespiratory Fitness Is Related to Physical Inactivity, Metabolic Risk Factors, and Atherosclerotic Burden in Glucose-Intolerant Renal Transplant Recipients

Abstract: The mechanisms of reduced cardiorespiratory fitness (CF) in renal transplant recipients (RTR) have not been studied closely. This study evaluated the relationships between CF and specific cardiovascular risk factors (metabolic syndrome [MS], physical inactivity, myocardial ischemia, and atherosclerotic burden) in glucose-intolerant RTR. Data were recorded on 71 glucose-intolerant RTR (mean age 55 yr; 55% male; median transplant duration 5.7 yr). MS was defined using National Cholesterol Education Programme Adult Treatment Panel III criteria. Resting and exercise stress echocardiography were performed, and myocardial ischemia was identified by new or worsening wall motion abnormalities. Cardiorespiratory fitness was determined using peak oxygen uptake (VO(2)) by expired gas analysis. Atherosclerotic burden was assessed by carotid intima-media thickness (IMT). Mean peak VO(2) was 19 +/- 7 ml/kg per min and was significantly lower than predicted peak VO(2) (29 +/- 6 ml/kg per min; P < 0.001). Patients with MS (63%) had reduced CF (17 +/- 6 versus 22 +/- 8 ml/kg per min; P = 0.001) and were more likely to be physically inactive (76 versus 48%; P = 0.02). CF was reduced in 14 patients with myocardial ischemia (15 +/- 3 versus 20 +/- 7 ml/kg per min; P = 0.05). CF was positively correlated with male gender, height, and physical activity and inversely correlated with number of MS risk factors and IMT (adjusted R(2) = 0.66). Carotid IMT added incremental value to clinical variables in determining VO(2) (adjusted R(2) = 0.65 versus 0.63; P = 0.04). Reduced CF is associated with physical inactivity, MS, and atherosclerotic burden in glucose-intolerant RTR. Further studies should address whether increasing exercise and modifying MS risk factors improve CF in RTR.

Single-substrate cholesteric liquid crystal displays by colloidal self-assembly

Abstract: We report a single-substrate method for fabrication of reflective and bistable cholesteric liquid crystal displays on flexible substrates based on self-assembly of uniform droplets of liquid crystal in a polymer matrix to create a close-packed monolayer. The displays may be made on a large scale and exhibit switching voltages, brightness, and contrast approaching two-substrate methods such as the two-substrate polymerization-induced phase separation method.