Mouse models of prostate adenocarcinoma with the capacity to monitor spontaneous carcinogenesis by bioluminescence or fluorescence

The application of Cre/loxP technology has resulted in a new generation of conditional mouse models of prostate cancer. Here, we describe the improvement of the conditional Pten deletion model of prostate adenocarcinoma by combining it with either a conditional luciferase or enhanced green fluorescent protein reporter line. In these models, the recombination mechanism that inactivates the Pten alleles also activates the reporter gene. In the luciferase reporter model, the growth of the primary cancer can be followed noninvasively by bioluminescence imaging (BLI). Surgical castration of tumor-bearing animals leads to a reduced bioluminescence signal corresponding to tumor regression that is verified at necropsy. When castrated animals are maintained, the emergence of androgen depletion-independent cancer is detected using BLI at times varying from 7 to 28 weeks postcastration. The ability to monitor growth, regression, or relapse of the tumor with the use of BLI lead to the collection of tumors at different stages of development. By comparing the distribution of phenotypically distinct populations of epithelial cells in cancer tissues, we noted that the degree of hyperplasia of cells with neuroendocrine differentiation significantly increases in the recurrent cancer relative to the primary cancer, a characteristic which may parallel the appearance of a neuroendocrine phenotype in human androgen depletion-independent cancer. The enhanced green fluorescent protein model, at necropsy, can provide an opportunity to locate or assess tumor volume or to isolate enriched populations of cancer cells from tumor tissues via fluorescence-based technologies. These refined models should be useful in the elucidation of mechanisms of prostate cancer progression, and for the development of approaches to preclinical intervention.     

Lupus nephritis. Clinicopathological correlation

OBJECTIVE: To classify all renal biopsies of lupus nephritis patients presenting in the last 10 years, according to the modified World Health Organization (WHO) classification using the facilities of light, fluorescent, and electron microscopy. To assess the activity and chronicity indices of renal biopsies according to the National Institute of Health protocol, and to correlate the histological findings with the clinical features of the patients presented up to the time of biopsy. METHODS: Seventy-eight patients with lupus nephritis, biopsied over 10 years between January 1995 to December 2005 in King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia were reviewed by 2 histopathologists with the assistance of a nephrologist. RESULTS: The predominant histological type was WHO class IV. Patients of this class were more commonly associated with microhematuria, elevated proteinuria, and renal insufficiency. Active and chronic lesions were more likely to occur in patients of class III/IV. These patients were also more likely to have evidence of clinical renal disease than patients in class II. There was a significant association between nephrotic syndrome and class V lupus nephritis. CONCLUSION: Although the clinical and pathological correlation demonstrated a significant relationship between underlying histopathology and the clinical course of the patient, however, the biopsy findings did not uniformly correlate with the clinical features. Moreover, the status prediction of lupus nephritis patients based on clinical information alone was significantly enhanced by information obtained from renal biopsy.     

The Heartfile Lodhran CVD prevention project--end of project evaluation

Mainstream preventive interventions often fail to reach poor populations with a high risk of cardiovascular diseases (CVDs) in Pakistan. A community-based CVD primary prevention project aimed at developing approaches to reduce risk factors in such populations was established by Heartfile in collaboration with the National Rural Support Program in the district of Lodhran. The project implemented a range of activities integrated with existing social and health service mechanisms during a three year intervention period 2000/01-03/04. These were targeted in 4 key settings: community health education, mass media interventions, training of health professionals and health education through Lady Health Workers. The project received support from the Department for International Development, U.K. At the community level, a pre-test-post-test quasi-experimental design was used for examining project outcomes related to the community component of the intervention. Pre and post-intervention (training) evaluations were conducted involving all health care providers in randomly selected workshops in order to determine baseline levels of knowledge and the impact of training on knowledge level. In order to assess practices of physician and non-physician health care providers patient interviews, with control comparisons were conducted at each health care facility. Significant positive changes were observed in knowledge levels at a community level in the district of intervention compared with baseline knowledge levels particularly in relation to a heart healthy diet, beneficial level of physical activity, the causes of high blood pressure and heart attack and the effects of high blood pressure and active and passive smoking on health. Significant changes in behaviors at a practice level were not shown in the district of intervention. However the project played a critical role in spurring national action for the prevention and control of non-communicable diseases and introducing sustainable public health interventions for poor communities in Pakistan.     

Inactivation of endothelial derived relaxing factor by oxidized lipoproteins.

Endothelial cell derived relaxing factor (EDRF) mediated relaxation of blood vessels is impaired in vessels exposed to lipoproteins in vitro and in arteries of hyperlipidemic humans and animals. To investigate the mechanism by which lipoproteins impair the effects of EDRF, which is likely nitric oxide (NO) or a related molecule, we have bioassayed EDRF/NO activity by measuring its ability to increase cGMP accumulation in rat fetal lung cultured fibroblasts (RFL-6 cells). Low density lipoprotein modified by oxidation (ox-LDL) induced a concentration-dependent inhibition of EDRF activity that had been released from bovine aortic endothelial cells (BAEC) stimulated with bradykinin or the calcium ionophore A23187. In addition, lipoproteins directly impaired authentic NO-induced stimulation of cGMP accumulation in the detector cells; stimulation by sodium nitroprusside was unaffected. Ox-LDL or oxidized HDL3 were highly potent in blocking NO-stimulated cGMP accumulation with EC50's of approximately 1 microgram/ml. Lipid extracted from ox-LDL blocked NO-stimulated cGMP accumulation to about the same extent as intact ox-LDL, while the protein component of ox-LDL did not inhibit the cGMP response. These results suggest that the lipid component of oxidized lipoproteins inactivate EDRF after its release from endothelial cells.     

Plasma fibrinogen level as possible prognostic biomarker in diffuse large B-cell lymphoma

Objectives: Although many studies have assessed numerous molecular and immunohistochemical prognostic markers for diffuse large Bcell lymphoma (DLBCL), there is always a need for simple widely available markers. This study was planned to illustrate the clinical significance of baseline plasma fibrinogen levels in DLBCL patients.

Methods: We prospectively investigated 76 DLBCL patients treated with rituximab plus cyclophosphamide, vincristine, doxorubicin and hostacortine between August 2015 and February 2018. Baseline plasma fibrinogen level was measured and correlated with patients’ clinical features, laboratory parameters, response to therapy, progression-free survival and overall survival.

Results: Significant association between fibrinogen level and clinical features such as the presence of B symptoms (P?<?.001) and clinical stage (P?<?.001) was observed while no association with age, gender, number of involved extranodal sites, performance status and international prognostic index (IPI) was found. Baseline fibrinogen level was significantly related to laboratory parameters including red cell distribution width (RDW) (P?<?.001), platelet count (P?=?.02), serum lactate dehydrogenase (LDH) (P?=?.009) and B2-microglobulin (P?=?.008). No statistically significant correlations were detected between baseline fibrinogen levels; and response to therapy, progression-free survival and overall survival.

Conclusion: Baseline plasma fibrinogen level did not show prognostic significance for DLBCL patients, although it was associated with patients’ clinical features and laboratory parameters. Being simple, cheap and widely available laboratory test, its use should be encouraged routinely in clinical practice to precisely clarify its predictive merit.     

High dietary fructose induces a hepatic stress response resulting in cholesterol and lipid dysregulation

High-fructose feeding causes diet-induced alterations of lipid metabolism and decreased insulin sensitivity with alterations of hepatic pyruvate dehydrogenase and hepatic very low-density lipoprotein secretion. Inflammatory cytokines also induce dramatic changes in lipid metabolism, particularly in serum triglycerides via increased hepatic secretion and/or delayed clearance of very low-density lipoprotein. The aim of this study was to determine whether the mechanism of lipid dysregulation in the high-fructose diet is induced by stress response pathways. Animals were fed a high-fructose diet for 14 d to establish hypertriglyceridemia and then were treated with lipoxygenase inhibitors for 4 d concurrent with the diet. At the end of drug treatment, the animals were divided into two groups and treated with lipopolysaccharide or a vehicle. Serum samples were taken pretreatment and posttreatment, and liver tissue was harvested at the end of study. Serum samples were tested for metabolic parameters, and the tissue samples were tested for metabolic and stress pathway responses. Our results show that fructose-fed rats have changes in the c-Jun N-terminal kinase pathway with correspondingly elevated activator protein-1 activity, consistent with an inflammatory response. Treatment with lipoxygenase inhibitors reversed the hypertriglyceridemia and also reduced activator protein-1 activation, suggesting that the basis for lipid dysregulation in this model is due to activation of inflammatory pathways in the liver.     

Gonadal effects on plasma ACE activity in mice

Angiotensin-converting enzyme (ACE) regulates blood pressure and is an important target in the management of hypertension. Hypertension is a gender biased disease. Plasma ACE activity is significantly higher in male mice (309 U/l) than female mice (237 U/l) and is reduced significantly upon gonadectomy to 224 and 209 U/l, respectively. Although, the gonads influence plasma ACE activity in both male and female mice, the effect is more pronounced in male mice. Plasma ACE is derived from the cleavage of tissue ACE and lung has the highest concentration of tissue ACE. However, lung ACE activity is not gender dimorphic but increases significantly upon gonadectomy in both male and female. ACE mRNA level in the lung is not influenced by gender or gondaectomy. Therefore, the gonads affect plasma ACE activity by influencing cleavage of tissue ACE to plasma ACE and/or decrease stability of plasma ACE in gonadectomized mice is mediated.