873 research outputs found
Risk factors associated with reticular pseudodrusen versus large soft drusen
PURPOSE: To investigate genetic, environmental, and systemic risk factors in prospectively identified subjects with the age-related macular degeneration (AMD) phenotypes of (1) reticular pseudodrusen without large soft drusen and (2) large soft drusen without reticular pseudodrusen. DESIGN: Prospective case-case comparison. METHODS: In a clinical practice setting, patients with AMD were sequentially screened using clinical examination and scanning laser ophthalmoscopy imaging to prospectively identify subjects (n = 73) with the phenotypes of (1) reticular pseudodrusen without large soft drusen (n = 30) or (2) large soft drusen without reticular pseudodrusen (n = 43). Subjects were genotyped for 2 alleles associated with AMD, age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH). A questionnaire was administered to collect history of smoking, hypertension, diabetes, and hyperlipidemia, as well as personal and family history of AMD. RESULTS: The reticular pseudodrusen group was older (median age 87 vs 81 years, P = .04) and had more female subjects (83.3% vs 48.8%, P = .003), later ages of AMD onset (83 vs 70 years, P = .0005), and a greater frequency of hypertension (76.7% vs 55.8%, P = .08). No significant differences were found in the distribution of the ARMS2 risk allele (P = .4) between the reticular pseudodrusen (homozygous = 20.0%; heterozygous = 56.7%) and large soft drusen (homozygous = 19.0%; heterozygous = 42.9%) phenotypes, or in the distribution of the CHF risk allele (P = .7) between the reticular pseudodrusen (homozygous = 26.7%; heterozygous = 56.7%) and large soft drusen (homozygous = 21.4%; heterozygous = 66.7%) phenotypes. CONCLUSIONS: The reticular pseudodrusen phenotype was associated with increased age, later age of AMD onset, and female sex
Clinical disorders affecting mesopic vision
Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized
Idiopathic osteonecrosis of the medial tibial plateau
Osteonecrosis of the medial tibial plateau is characterized by acute pain on the medial aspect of the knee. Progression can lead to articular collapse and requires early diagnosis and treatment. We studied seven patients affected of idiopathic osteonecrosis of the tibial plateau. The mean age was 62 years and the mean follow-up 42 months. We performed roentgenograms in all patients, bone scans in three patients and magnetic resonance image (MRI) in five. MRI shows T1-weighted low-intensity signal and T2-weighted high-intensity signal with a surrounding area of intermediate low-intensity signal. An increased focal uptake was seen at bone scan. Histological findings showed necrotic bone with empty lacunae. Surgical treatment consisted of tibial subchondral drilling in four patients-two of them by failure of conservative treatment, and a total knee arthroplasty in other two. One patient had a satisfactory evolution with conservative treatment. Idiopathic osteonecrosis of the tibial plateau must be considered in elderly patients with knee pain over the medial tibial plateau. At early stages, decompression with tibial drilling must be considered. This procedure allows a prompt and effective relief of symptom
Is EGFR expression altered following postoperative chemotherapy for colorectal adenocarcinoma?
BACKGROUND: There is immunohistochemical evidence to suggest that expression of epidermal growth factor receptor (EGFR) in primary colorectal adenocarcinoma predicts its expression in recurrent disease. This study investigates whether postoperative chemotherapy affects the degree of concordance between EGFR statuses of the two tumors. METHODS: Thirty-three patients were identified from the files of Sunnybrook Health Sciences Center from July 1994 to June 2005. All patients had resection of their primary tumors and their distant recurrences. Eighteen patients received postoperative chemotherapy, 3 of which also received postoperative radiation therapy. Representative primary and recurrent tumor sections were stained using mouse anti-EGFR antibodies and only membranous staining of malignant cells was recorded. Results were reported as negative (no staining), 1+ (positivity in <50% of cells) or 2+ (positivity in >50% of cells). RESULTS: EGFR immunostaining in the 15 patients, who received no postoperative chemotherapy, was decreased in 3 recurrences, remained the same in 10 and increased in 2. In the group of 18 patients who received postoperative chemotherapy, EGFR immunostaining was decreased in 6 recurrences, remained the same in 9 and increased in 3 (p = 0.6598). In patients who received postoperative chemotherapy, the odds ratio for a recurrence to show lower levels of EGFR immunostaining compared to its originally resected primary was 4.75 (CI = 0.94 β 26.73). CONCLUSION: These preliminary data suggest that recurrences following postoperative chemotherapy are likely to have lower levels of EGFR expression compared to cases who receive no chemotherapy. Although the difference of immunostaining profiles between the two groups was not statistically significant, this observation might impact the management of these patients by targeted biologic therapies and its practical implications need further validation in larger series
Legal Facts and Reasons for Action: Between Deflationary and Robust Conceptions of Lawβs Reason-Giving Capacity
This chapter considers whether legal requirements can constitute reasons for action independently of the merits of the requirement at hand. While jurisprudential opinion on this question is far from uniform, sceptical views are becoming increasingly dominant. Such views typically contend that, while the law can be indicative of pre-existing reasons, or can trigger pre-existing reasons into operation, it cannot constitute new reasons. This chapter offers support to a somewhat less sceptical position, according to which the fact that a legal requirement has been issued can be a reason for action, yet one that is underpinned by bedrock values which law is apt to serve. Notions discussed here include a value-based conception of reasons as facts ; a distinction between complete and incomplete reasons ; and David Enochβs idea of triggering reason-giving. Following a discussion of criticism against the view adopted here, the chapter concludes by considering some more βrobustβ conceptions of lawβs reason-giving capacity
Ca2+-induced changes in energy metabolism and viability of melanoma cells
Cancer cells are characterized by a high rate of glycolysis, which is their primary energy source. We show here that a rise in intracellular-free calcium ion (Ca2+), induced by Ca2+-ionophore A23187, exerted a deleterious effect on glycolysis and viability of B16 melanoma cells. Ca2+-ionophore caused a dose-dependent detachment of phosphofructokinase (EC 2.7.1.11), one of the key enzymes of glycolysis, from cytoskeleton. It also induced a decrease in the levels of glucose 1,6-bisphosphate and fructose 1,6-bisphosphate, the two stimulatory signal molecules of glycolysis. All these changes occurred at lower concentrations of the drug than those required to induce a reduction in viability of melanoma cells. We also found that low concentrations of Ca2+-ionophore induced an increase in adenosine 5β²-triphosphate (ATP), which most probably resulted from the increase in mitochondrial-bound hexokinase, which reflects a defence mechanism. This mechanism can no longer operate at high concentrations of the Ca2+-ionophore, which causes a decrease in mitochondrial and cytosolic hexokinase, leading to a drastic fall in ATP and melanoma cell death. The present results suggest that drugs which are capable of inducing accumulation of intracellular-free Ca2+ in melanoma cells would cause a reduction in energy-producing systems, leading to melanoma cell death. Β© 1999 Cancer Research Campaig
Alteration of gene expression profiles during mycoplasma-induced malignant cell transformation
BACKGROUND: Mycoplasmas are the smallest microorganisms capable of self-replication. Our previous studies show that some mycoplasmas are able to induce malignant transformation of host mammalian cells. This malignant transformation is a multistage process with the early infection, reversible and irreversible stages, and similar to human tumor development in nature. The purpose of this study is to explore mechanisms for this malignant transformation. METHODS: To better understand mechanisms for this unique process, we examined gene expression profiles of C3H cells at different stages of the mycoplasma-induced transformation using cDNA microarray technology. A total of 1185 genes involved in oncogenesis, apoptosis, cell growth, cell-cycle regulation, DNA repair, etc. were examined. Differences in the expression of these genes were compared and analyzed using the computer software AtlasImage. RESULTS: Among 1185 genes screened, 135 had aberrant expression at the early infection stage, 252 at the reversible stage and 184 at the irreversible stage. At the early infection stage, genes with increased expression (92 genes) were twice more than those with decreased expression (42 genes). The global gene expression at the reversible stage appeared to be more volatile than that at any other stages but still resembled the profile at the early infection stage. The expression profile at the irreversible stage shows a unique pattern of a wide range of expression levels and an increased number of expressing genes, especially the cancer-related genes. Oncogenes and tumor suppressors are a group of molecules that showed significant changes in expression during the transformation. The majority of these changes occurred in the reversible and irreversible stages. A prolonged infection by mycoplasmas lead to the expression of more cancer related genes at the irreversible stage. CONCLUSION: The results indicate that the expression profiles correspond with the phenotypic features of the cells in the mycoplasma induced transformation process. The early mycoplasma infection stage shares a common phenomenon with many other acute infections, genes with increased expression significantly outnumbering those with decreased expression. The reversible stage is a transition stage between benignancy and malignancy at the molecular level. Aberrant expression of oncogenes and tumor repressors plays a key role in mycoplasma-induced malignant transformation
High- and Low-Affinity Epidermal Growth Factor Receptor-Ligand Interactions Activate Distinct Signaling Pathways
Signaling mediated by the Epidermal Growth Factor Receptor (EGFR) is crucial in normal development, and aberrant EGFR signaling has been implicated in a wide variety of cancers. Here we find that the high- and low-affinity interactions between EGFR and its ligands activate different signaling pathways. While high-affinity ligand binding is sufficient for activation of most canonical signaling pathways, low-affinity binding is required for the activation of the Signal transducers and activators of transcription (Stats) and Phospholipase C-gamma 1 (PLCΞ³1). As the Stat proteins are involved in many cellular responses including proliferation, migration and apoptosis, these results assign a function to low-affinity interactions that has been omitted from computational models of EGFR signaling. The existence of receptors with distinct signaling properties provides a way for EGFR to respond to different concentrations of the same ligand in qualitatively different ways
JACIE accreditation for blood and marrow transplantation: past, present and future directions of an international model for healthcare quality improvement.
Blood and marrow transplantation (BMT) is a complex and evolving medical speciality that makes substantial demands on healthcare resources. To meet a professional responsibility to both patients and public health services, the European Society for Blood and Marrow Transplantation (EBMT) initiated and developed the Joint Accreditation Committee of the International Society for Cellular Therapy and EBMT-better known by the acronym, JACIE. Since its inception, JACIE has performed over 530 voluntary accreditation inspections (62% first time; 38% reaccreditation) in 25 countries, representing 40% of transplant centres in Europe. As well as widespread professional acceptance, JACIE has become incorporated into the regulatory framework for delivery of BMT and other haematopoietic cellular therapies in several countries. In recent years, JACIE has been validated using the EBMT registry as an effective means of quality improvement with a substantial positive impact on survival outcomes. Future directions include development of Europe-wide risk-adjusted outcome benchmarking through the EBMT registry and further extension beyond Europe, including goals to faciliate access for BMT programmes in in low- and middle-income economies (LMIEs) via a 'first-step' process
- β¦