Dental management of patients with renal failure

Renal disease has become increasingly more prevalent in our society. There are many more people undergoing dialysis treatment and kidney transplants than there were only a decade ago. The dental care of these patients can be complex, given the medications associated with the disease and the medical conditions that result from inadequately functioning kidneys. This article reviews the literature regarding the dental management of patients with acute and chronic renal failure.     

Surgical management of a large retinal cyst in X-linked retinoschisis with internal drainage: Report of an unusual case

Although X-linked retinoschisis is a common retinal degeneration condition, the presence of a large retinal cyst obscuring the visual axis in an infant is a rare presentation. Herein, we describe such a case of a child who presented to us with the diagnosis of retinal detachment in both the eyes. However, following multimodal imaging and electrophysiology, the child was found to have bilateral juvenile retinoschisis with a large retinoschisis cyst involving the visual axis seen intraoperatively in the left eye. A limbal approach followed by lensectomy was used to excise the inner retinal layer of the cyst. The intracystic fluid was then drained and the stretched retinal vessels were endocauterized and severed without causing any iatrogenic outer retinal breaks and retinal detachment. The correct diagnosis and meticulous preoperative planning of the surgical procedure helped us manage this challenging case with a favorable anatomical and functional outcome.     

Does coping mediate the relationship between familism and caregiver outcomes?

Objectives: The sociocultural model of stress and coping, which despite receiving support from several studies conducted with diverse ethnic groups, has yet to be tested longitudinally or used within the context of positive caregiver outcomes. The aim of the current study was to test a specific component of the model, which posits that caregiver coping will be influenced by the cultural value of familism (feelings of solidarity and loyalty among family members), which will in turn affect caregiver outcomes.

Method: A questionnaire was completed by 123 family caregivers in the UK assessing familism, use of coping strategies, caregiver gains, anxiety and depression at three time points over nine months.

Results: Mediation analysis followed guidelines proposed by Baron and Kenny. Religious coping and positive reframing at time 2 (T2) were found to significantly mediate between familism values at time 1 (T1) and caregiver gains at time 3 (T3). Behavioural disengagement at T2 was found to mediate between familism at T1 and caregiver depression atT3. Additionally familism was found to be positively associated with both negative and positive aspects of caregiving.

Conclusion: Our longitudinal findings suggest that interventions and services acknowledging caregiver values and the associated coping responses may prove beneficial.     

Persistence of urothelial carcinoma of the bladder risk among former smokers: Results from a contemporary,prospective cohort study

ObjectivesCigarette smoking is a known risk factor for urothelial carcinoma (UC) of the bladder. However, the persistence of an increased risk for UC following smoking cessation is not well established. We assessed the risk of UC among former smokers using a recent, prospective cohort with a high proportion of former smokers.Materials and methodsStudy participants were members of the VITamins And Lifestyle cohort (VITAL), a group of 77,719 men and women between the ages of 50 and 76 years from western Washington State. Smoking history and other risk factors were obtained at the time of recruitment. The primary outcome was a new diagnosis of UC (n =385), as determined through linkage to a population-based cancer registry.Results and limitationsThe cohort included 8% current and 44% former smokers, and among the UC cases, 15% were current and 60% former smokers. Both the current and former smoker had an increased risk of UC compared with never smokers (hazard ratio [HRs]: 3.81; 95% confidence intervals [CI] 2.71–5.35 and 2.0; 95% CI 1.55–2.58, respectively). Among former smokers, the risk of UC increased with the pack-years smoked and decreased with the years since quitting. When both the measures of smoking were considered together, the risk of UC was similar for long-term quitters and recent quitters for a given level of pack-years. For example, for those with pack-years of 22.5–37.5, the HR of UC was 1.91 (95% CI 1.17–3.11) for the distant quitters (≥23.5 y before baseline) and HR = 1.92 (95% CI 1.26–2.94) among the recent quitters. Limitations include the small number of cases at the extremes of smoking history and errors in self-reported smoking history.ConclusionsThe risk of bladder cancer in former smokers remains elevated>32 years after quitting, even among those with moderate smoking histories. This argues that a history of smoking confers a lifelong increased risk of UC.     

Advance Directive Utilization Is Associated with Less Aggressive End-of-Life Care in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation (HCT) is associated with significant morbidity and mortality, making advance care planning (ACP) and management especially important in this patient population. A paucity of data exists on the utilization of ACP among allogeneic HCT recipients and the relationship between ACP and intensity of healthcare utilization in these patients. We performed a retrospective review of patients receiving allogeneic HCT at our institution from 2008 to 2015 who had subsequently died after HCT. Documentation and timing of advance directive (AD) completion were abstracted from the electronic medical record. Outcomes of interest included use of intensive care unit (ICU) level of care at any time point after HCT, within 30 days of death, and within 14 days of death; use of mechanical ventilation at any time after HCT; and location of death. Univariate logistic regression was performed to explore associations between AD completion and each outcome. Of the 1031 patients who received allogeneic HCT during the study period, 422 decedents (41%) were included in the analysis. Forty-four percent had AD documentation prior to death. Most patients (69%) indicated that if terminally ill, they did not wish to be subjected to life-prolonging treatment attempts. Race/ethnicity was significantly associated with AD documentation, with non-Hispanic white patients documenting ADs more frequently (51%) compared with Hispanic (22%) or Asian patients (35%; P?=?.0007). Patients with ADs were less likely to use the ICU during the transplant course (41% for patients with ADs versus 52% of patients without ADs; P?=?.03) and also were less likely to receive mechanical ventilation at any point after transplantation (21% versus 37%, P?<?.001). AD documentation was also associated with decreased ICU use at the end of life; relative to patients without ADs, patients with ADs were more likely to die at home or in hospital as opposed to in the ICU (odds ratio, .44; 95% confidence interval, .27 to .72). ACP remains underused in allogeneic HCT. Adoption of a systematic practice to standardize AD documentation as part of allogeneic HCT planning has the potential to significantly reduce ICU use and mechanical ventilation while improving quality of care at end of life in HCT recipients.     

Metformin increases degradation of phospholamban via autophagy in cardiomyocytes

Phospholamban (PLN) is an effective inhibitor of the sarco(endo)plasmic reticulum Ca²⁺ ATPase (SERCA). Here, we examined PLN stability and degradation in primary cultured mouse neonatal cardiomyocytes (CMNCs) and mouse hearts using immunoblotting, molecular imaging, and [³⁵S]methionine pulse-chase experiments, together with lysosome (chloroquine and bafilomycin A1) and autophagic (3-methyladenine and Atg5 siRNA) antagonists. Inhibiting lysosomal and autophagic activities promoted endogenous PLN accumulation, whereas accelerating autophagy with metformin enhanced PLN degradation in CMNCs. This reduction in PLN levels was functionally correlated with an increased rate of SERCA2a activity, accounting for an inotropic effect of metformin. Metabolic labeling reaffirmed that metformin promoted wild-type and R9C PLN degradation. Immunofluorescence showed that PLN and the autophagy marker, microtubule light chain 3, became increasingly colocalized in response to chloroquine and bafilomycin treatments. Mechanistically, pentameric PLN was polyubiquitinylated at the K3 residue and this modification was required for p62-mediated selective autophagy trafficking. Consistently, attenuated autophagic flux in HECT domain and ankyrin repeat-containing E3 ubiquitin protein ligase 1-null mouse hearts was associated with increased PLN levels determined by immunoblots and immunofluorescence. Our study identifies a biological mechanism that traffics PLN to the lysosomes for degradation in mouse hearts.Phospholamban (PLN) is a 52-amino acid peptide located in the sarcoplasmic reticulum (SR) membrane in cardiac, slow-twitch skeletal, and smooth muscle, where it exists as a monomer or pentamer. Whereas monomeric PLN physically interacts with sarco(endo)plasmic reticulum Ca²⁺ ATPase type 2a (SERCA2a) to antagonize its function, pentameric PLN complexes are thought to be a reservoir of inactive PLN (1–3). The physical interaction between SERCA2a and PLN reduces the apparent affinity of SERCA2a for Ca²⁺, thereby making SERCA2a less active in transporting Ca²⁺ from the cytoplasm to the lumen of the SR at the same concentration of cytoplasmic Ca²⁺. The physical interaction between the two proteins is regulated by phosphorylation of PLN at Ser16 by protein kinase A or at Thr17 by Ca²⁺/calmodulin-dependent protein kinase II (2). Phosphorylation of PLN reduces its affinity for SERCA2a, thereby increasing SERCA2a activity (2). Evidence from transgenic mice also supports the inhibitory function of PLN. Although targeted PLN deletion enhances baseline cardiac performance, cardiac-specific overexpression of superinhibitory forms of PLN leads to decreases in the affinity of SERCA2a for Ca²⁺ (2). These observations underscore the primary role of PLN as a regulator of SERCA2a activity and, therefore, as a crucial regulator of cardiac contractility. PLN inhibition of SERCA2a can be reversed by either external (i.e., activation of β-adrenergic receptors) or internal (i.e., increased intracellular Ca²⁺ concentration) stimuli.Previous studies identified three PLN mutations in families of patients with hereditary dilated cardiomyopathy. These mutations, the substitution of Cys for Arg9 (R9C) (4), Arg14 deletion (RΔ14) (5), and the substitution of TGA for TAA in the Leu39 codon, creating a stop codon (L39stop) (6), also lead to dilated cardiomyopathy in transgenic mice. At the cellular level, ectopically expressed RΔ14 and L39stop PLN mutants localize at the plasma membrane in HEK-293T cells, cultured mouse neonatal cardiomyocytes, and cardiac fibroblasts, whereas wild-type and the R9C mutant reside within the endoplasmic reticulum (ER)/SR (6, 7). These data, together with a recent study by Sharma et al. (8), suggest a highly ordered trafficking of PLN, ultimately ensuring correct localization, and thus function, within the SR. However, PLN trafficking and degradation mechanisms in mammalian cardiomyocytes have not been clearly established.Protein degradation and clearance of damaged organelles are critical for cellular physiology, and failure in proper clearance has been shown to have pathological repercussions (9). Autophagy is a major mechanism that mediates protein and organelle degradation in response to external and internal signals. External stimulation through pharmacological agonists, such as metformin and rapamycin, promotes autophagy via AMP-activated protein kinase (AMPK) and mammalian target of rapamycin signal pathways, whereas amino acid starvation and an increased intracellular AMP/ATP ratio serve as internal signals to promote autophagy via the Ca²⁺/Calmodulin-dependent kinase kinase-β (10). Steps in the autophagy pathway involve nucleation of targeted macromolecules on the ER membrane, trafficking of autophagosomes to lysosomes and, finally, fusion of the autophagosome-lysosome, resulting in targeted protein degradation (11). In the heart, autophagy plays a crucial role in response to insults, in part by relieving ER stress (12) and removing damaged mitochondria (13). Loss of autophagy could result in irreversible apoptosis and reduced cardiac functioning (14).To characterize PLN degradation, we conducted a series of assays in cultured mouse neonatal cardiomyocytes (CMNCs) and the hearts of HECT domain and ankyrin repeat-containing E3 ubiquitin protein ligase 1 (Hace1)-null mice. Our results show that PLN degradation required both polyubiquitinylation and p62-mediated selective autophagy in CMNCs. Loss of HACE1 was associated with increased PLN levels, supporting the notion that selective autophagy modulates PLN degradation in vivo. Metformin promoted wild-type and R9C PLN degradation through autophagic pathways, resulting in metformin-induced inotropic enhancement.     

Cdc42: Role in Cancer Management

Contribution of Cdc42, a member of Rho family, has been characterized for the beginning of variety of cellular responses including cellular transformation, cell division, cell invasion, migration, invadopodia formation, enzyme activity, filopodia formation, and cell polarity in cells. Deregulation of Cdc42 can alter the normal functioning of the cells, responsible for the initiation of signaling pathways and is correlated with several pathogenic processes such as cancer. Therefore, maintaining the level of Cdc42 and its effectors in cells, tumor progression can be controlled. Therefore, it can be suggested that deeper understanding about the Cdc42 contribution in cancer cell progression at molecular level can approach to the development of Cdc42 inhibitors in cancer management.     

Non-pathogenic Borrelia burgdorferi expressing Treponema pallidum TprK and Tp0435 antigens as a novel approach to evaluate syphilis vaccine candidates

Background

Syphilis is resurgent in many developed countries and still prevalent in developing nations. Current and future control campaigns would benefit from the development of a vaccine, but although promising vaccine candidates were identified among the putative surface-exposed integral outer membrane proteins of the syphilis spirochete, immunization experiments in the rabbit model using recombinant antigens have failed to fully protect animals upon infectious challenge. We speculated that such recombinant immunogens, purified under denaturing conditions from Escherichia coli prior to immunization might not necessarily harbor their original structure, and hypothesized that enhanced protection would result from performing similar immunization/challenge experiments with native antigens.