Bradley E. Aouizerat

Abstract

The aims of this replication study were to determine if subgroups of oncology outpatients receiving active treatment could be identified based on their experience with the symptoms of fatigue, sleep disturbance, depression, and pain; whether patients in these subgroups differed on selected demographic, disease, and treatment characteristics; and if patients in these subgroups differed on functional status and quality of life (QOL). A convenience sample of 228 oncology outpatients was recruited from seven outpatient settings in Israel. Patients completed a demographic questionnaire, a Karnofsky Performance Status score, the Multidimensional Quality of Life Scale-Cancer, the Lee Fatigue Scale, the General Sleep Disturbance Scale, the Center for Epidemiological Studies-Depression Scale, and a numeric rating scale of worst pain intensity. Cluster analysis was used to identify the patient subgroups based on their symptom experience. Four relatively distinct patient subgroups were identified based on their experiences with the above symptoms (i.e., low levels of all four symptoms (32.9%), low levels of pain and high levels of fatigue (18.0%), high levels of pain and moderate levels of fatigue (42.5%), and high levels of all four symptoms (6.6%). No differences were found among the four subgroups on any demographic, disease, or treatment characteristics. The subgroup of patients who reported high levels of all four symptoms reported the worst functional status and poorest QOL. In conclusion, differences in the symptom experience of oncology outpatients suggest that patients may harbor different phenotypic characteristics (e.g., environmental or physiologic) or genetic determinants for experiencing symptoms that are independent of demographic, disease, and treatment characteristics.

Abstract

Fatigue is the most common and distressing symptom reported by patients undergoing radiation therapy (RT). However, limited information is available on the trajectories of fatigue, as well as on the predictors of interindividual variability in fatigue. This study evaluated a sample of patients who underwent RT for prostate cancer to examine how ratings of evening and morning fatigue changed from the time of simulation to four months after the completion of RT and to investigate whether specific patient, disease, and symptom characteristics predicted the initial levels of fatigue and/or characteristics of the trajectories of evening and morning fatigue. Using hierarchical linear modeling, a large amount of interindividual variability was demonstrated in the trajectories of evening and morning fatigue. Findings from this study suggest that younger men with a higher level of fatigue at the time of the simulation visit were at increased risk for higher levels of evening and morning fatigue over the course of RT. In addition, the level of morning fatigue over the course of RT appears to depend on the patient's level of depression at the time of the simulation visit. In future studies, the use of hierarchical linear modeling as an analytic tool will assist in the identification of patients who are most at risk for prolonged fatigue trajectories. This type of analysis may lead to the identification of subgroups of patients who are at higher risk for negative outcomes and who require different types of interventions for the fatigue associated with RT.

Abstract

Low serum HDL-cholesterol (HDL-C) is a major risk factor for coronary artery disease. We performed targeted genotyping of a 12.4 Mb linked region on 16q to test for association with low HDL-C by using a regional-tag SNP strategy. We identified one SNP, rs2548861, in the WW-domain-containing oxidoreductase (WWOX) gene with region-wide significance for low HDL-C in dyslipidemic families of Mexican and European descent and in low-HDL-C cases and controls of European descent (p = 6.9 × 10-7). We extended our investigation to the population level by using two independent unascertained population-based Finnish cohorts, the cross-sectional METSIM cohort of 4,463 males and the prospective Young Finns cohort of 2,265 subjects. The combined analysis provided p = 4 × 10-4 to 2 × 10-5. Importantly, in the prospective cohort, we observed a significant longitudinal association of rs2548861 with HDL-C levels obtained at four different time points over 21 years (p = 0.003), and the T risk allele explained 1.5% of the variance in HDL-C levels. The rs2548861 resides in a highly conserved region in intron 8 of WWOX. Results from our in vitro reporter assay and electrophoretic mobility-shift assay demonstrate that this region functions as a cis-regulatory element whose associated rs2548861 SNP has a specific allelic effect and that the region forms an allele-specific DNA-nuclear-factor complex. In conclusion, analyses of 9,798 subjects show significant association between HDL-C and a WWOX variant with an allele-specific cis-regulatory function.

Abstract

The majority of the research on the various aspects of symptom management has focused on individual symptoms. However, patients with cancer often experience multiple symptoms simultaneously as a result of their disease and treatment. In 2001, symptom management researchers began to study the impact of symptom clusters on patient outcomes. Over the past 6 years, a number of conceptual reviews as well as several research studies have been published on symptom clusters in oncology patients. This paper summarizes the conceptual basis for symptom cluster research, describes two conceptual approaches to symptom cluster research, and discusses the implications of symptom clusters for quality-of-life research. The paper concludes with an enumeration of the critical considerations that need to be addressed if this area of scientific inquiry is to move forward.

Abstract

Objectives: To examine symptom clusters in oncology patients; to determine if these symptom clusters might share a common biologic mechanism; and to describe potential biologic mechanisms that warrant investigation. Data Sources: Synthesis of the theoretical and research papers on symptom clusters. Conclusion: Definitive conclusions about whether there is a biologic basis for the clustering of symptoms cannot be determined at this time. The animal model of sickness behavior holds promise as a potential biologic mechanism for clustering symptoms. Implications for Nursing Practice: Until more definitive studies of symptom clusters are performed, clinicians need to monitor patients for the co-occurrence of multiple symptoms and develop appropriate management plans.

Abstract

Hypertriglyceridemia is a hallmark of many disorders, including metabolic syndrome, diabetes, atherosclerosis and obesity. A well-known cause is the deficiency of lipoprotein lipase (LPL), a key enzyme in plasma triglyceride hydrolysis. Mice carrying the combined lipase deficiency (cld) mutation show severe hypertriglyceridemia owing to a decrease in the activity of LPL and a related enzyme, hepatic lipase (HL), caused by impaired maturation of nascent LPL and hepatic lipase polypeptides in the endoplasmic reticulum (ER). Here we identify the gene containing the cld mutation as Tmem112 and rename it Lmf1 (Lipase maturation factor 1). Lmf1 encodes a transmembrane protein with an evolutionarily conserved domain of unknown function that localizes to the ER. A human subject homozygous for a deleterious mutation in LMF1 also shows combined lipase deficiency with concomitant hypertriglyceridemia and associated disorders. Thus, through its profound effect on lipase activity, LMF1 emerges as an important candidate gene in hypertriglyceridemia.

Abstract

Although the concept of the coagulation cascade represented a significant advance in the understanding of coagulation and served for many years as a useful model, more recent clinical and experimental observations demonstrate that the cascade/waterfall hypothesis does not fully and completely reflect the events of hemostasis in vivo. The goal of this article is to review the evolution of the theories of coagulation and their proposed models to serve as a tool when reviewing the research and practice literature that was published in the context of these different theories over time.

Abstract

In the absence of surrogate markers, the evaluation of suspected nonalcoholic fatty liver disease (NAFLD) is highly dependent on histological examination. The extent of sampling variability affecting the reliability of a single liver biopsy in patients with suspected NAFLD is poorly characterized. This prospective study aimed to correlate precise histological findings in paired biopsies - right and left lobe - in the diagnosis of NAFLD in morbidly obese subjects undergoing bariatric surgery employing both Brunt and Matteoni classifications and the NAFLD Activity Score (NAS). We also aimed to determine whether the composite histopathological findings of the two biopsies would improve diagnostic accuracy. Consecutive subjects had an intraoperative biopsy from both right and left lobes, evaluated and scored in a blinded manner. Intraobserver agreement was also assessed. Kappa coefficients of agreement were calculated. Forty-one subjects had acceptable biopsies. Agreement for steatosis was excellent and moderate for fibrosis. Concordance was only fair for most features of necroinflammation. Intraobserver agreement was only moderate for lobular inflammation. Excellent agreement was seen for the diagnosis of NASH using Brunt criteria and good agreement when using Matteoni and NAS scoring systems. Composite biopsy data particularly improved identification of hepatocyte ballooning. The diagnostic accuracy also improved substantially when composite features were compared with single-sided biopsy features, especially for the Matteoni and NAS scoring systems. In conclusion, significant sampling variability occurs in NAFLD, particularly for features of necroinflammation. This should be factored into the design of clinical trials and studies of the natural history of the disease.

Abstract

Nonalcoholic fatty liver disease (NAFLD) is a metabolic liver disease with widely variable phenotypes extending from simple steatosis, through nonalcoholic steatohepatitis (NASH) to cirrhosis and hepatocellular carcinoma. Inevitably, this reflects the interplay of well-recognized environmental factors and disease associations such as obesity and insulin resistance with host genetic factors, which are polygenic or complex in nature. Most of the observed phenotypic variability will probably be explained by variations in single nucleotide polymorphism frequency, although knowledge of the effect of most polymorphisms on biologic function is currently limited. Several observational studies of kindred with NASH suggest a genetic contribution. Most data characterizing genetic variation in different NAFLD phenotypes is derived from case-control association studies involving putative candidate genes. These candidate genes have been selected largely based upon the "two-hit hypothesis" of the pathogenesis of NAFLD, although other hypothesis-independent approaches can also be informative in gene selection. Thus far, candidate gene association studies have had significant limitations such as small cohort sizes and poor reproducibility. Rapid technologic developments are increasing the capability of detecting genetic variation. Identification of the genetic contribution to NAFLD will inform theories of disease pathogenesis and progression and ultimately improve management.

Abstract

Phospholipid transfer protein (PLTP) participates in key processes in lipoprotein metabolism, including interparticle phospholipid transfer, remodeling of HDL, cholesterol and phospholipid efflux from peripheral tissues, and the production of hepatic VLDL. The impact of PLTP on reverse cholesterol transport suggests that the gene may harbor sequence anomalies that contribute to disorders of HDL metabolism. The human PLTP gene was screened for sequence anomalies by DNA melting analysis in 276 subjects with hypoalphalipoproteinemia (HA) and 364 controls. The association with plasma lipid parameters was evaluated. We discovered 18 sequence variations, including four missense mutations and a novel polymorphism (c.-34G>C). In healthy controls, the c.-34G>C minor allele was associated with higher high density lipoprotein-cholesterol (HDL-C) and was depleted in subjects with HA. Linear regression models predict that possession of the rare allele decreases plasma triglyceride (TG) and TG/HDL-C and increases HDL-C independent of TG. Decreased PLTP activity was observed in one (p.R235W) of four (p.E72G, p.S119A, p.S124Y, and p.R235W) mutations in an in vitro activity assay. These findings indicate that PLTP gene variation is an important determinant of plasma lipoproteins and affects disorders of HDL metabolism.