Lifestyle modifications to prevent and control hypertension. 5. Recommendations on dietary salt. Canadian Hypertension Society,Canadian Coalition for High Blood Pressure Prevention and Control,Laboratory Centre for Disease Control at Health Canada,Heart and Stroke Foundation of Canada

OBJECTIVE: To provide updated, evidence-based recommendations concerning the effects of dietary salt intake on the prevention and control of hypertension in adults (except pregnant women). The guidelines are intended for use in clinical practice and public education campaigns. OPTIONS: Restriction of dietary salt intake may be an alternative to antihypertensive medications or may supplement such medications. Other options include other nonpharmacologic treatments for hypertension and no treatment. OUTCOMES: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered. EVIDENCE: A MEDLINE search was conducted for the period 1966-1996 using the terms hypertension, blood pressure, vascular resistance, sodium chloride, sodium, diet, sodium or sodium chloride dietary, sodium restricted/reducing diet, clinical trials, controlled clinical trial, randomized controlled trial and random allocation. Both trials and review articles were obtained, and other relevant evidence was obtained from the reference lists of the articles identified, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design and graded according to level of evidence. In addition, a systematic review of all published randomized controlled trials relating to dietary salt intake and hypertension was conducted. VALUES: A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension. BENEFITS, HARMS AND COSTS: For normotensive people, a marked change in sodium intake is required to achieve a modest reduction in blood pressure (there is a decrease of 1 mm Hg in systolic blood pressure for every 100 mmol decrease in daily sodium intake). For hypertensive patients, the effects of dietary salt restriction are most pronounced if age is greater than 44 years. A decrease of 6.3 mm Hg in systolic blood pressure and 2.2 mm Hg in diastolic blood pressure per 100 mmol decrease in daily sodium intake was observed in people of this age group. For hypertensive patients 44 years of age and younger, the decreases were 2.4 mm Hg for systolic blood pressure and negligible for diastolic blood pressure. A diet in which salt is moderately restricted appears not to be associated with health risks. RECOMMENDATIONS: (1) Restriction of salt intake for the normotensive population is not recommended at present, because of insufficient evidence demonstrating that this would lead to a reduced incidence of hypertension. (2) To avoid excessive intake of salt, people should be counselled to choose foods low in salt (e.g., fresh fruits and vegetables), to avoid foods high in salt (e.g., pre-prepared foods), to refrain from adding salt at the table and minimize the amount of salt used in cooking, and to increase awareness of the salt content of food choices in restaurants. (3) For hypertensive patients, particularly those over the age of 44 years, it is recommended that the intake of dietary sodium be moderately restricted, to a target range of 90-130 mmol per day (which corresponds to 3-7 g of salt per day). (4) The salt consumption of hypertensive patients should be determined by interview. VALIDATION: These recommendations were reviewed by all of the sponsoring organizations and by participants in a satellite symposium of the fourth International Conference on Preventive Cardiology. They have not been clinically tested. SPONSORS: The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada.     

Water-soluble rylene dyes as high-performance colorants for the staining of cells

The synthesis of perylene and terrylene chromophores carrying a single poly(ethylene oxide) chain is presented. These chromophores reveal a strong solvatochromic behavior: High fluorescence in nonpolar solvents and weak fluorescence in polar solvents which is mainly attributed to aggregation. Therefore, such chromophores are attractive candidates as sensitive fluorescent probes reflecting the polarity of their environment. In particular, their suitability for the staining of cellular membranes is presented in detail.     

Downregulation of beta2-microglobulin in human cord blood somatic stem cells after transplantation into livers of SCID-mice: an escape mechanism of stem cells?

Adherently growing, non-hematopoietic somatic stem cells isolated from human cord blood were stained with the fluorescent dye PKH26 and transplanted into livers of SCID-mice to examine a possible cell fate transition. Already 7 days after transplantation stem cells were well integrated into the liver tissue. Human albumin that was not expressed by the stem cells before transplantation was detectable in the host's livers after injection of cord blood stem cells. Human alpha1-antitrypsin was detectable in stem cells already before transplantation and remained positive in the mouse liver. The most interesting observation in this study was the downregulation of human beta2-microglobulin (beta2M) in the stem cells after transplantation: beta2M is expressed constitutively in our cord blood stem cells. However, beta2M was no longer detectable by RT-PCR in all tissues where human albumin and alpha1-antitrypsin were expressed after stem cell transplantation. beta2M is known to participate as an integral part of the major histocompatibility complex. Absence of beta2M makes the residual heavy chain inactive as an antigen. Thus, downregulation of beta2M may represent an escape mechanism from killer-T cells and may be a molecular mechanism explaining the recently described "immunological blindness" [37] of stem cells. In contrast to the results obtained after direct injection of stem cells as a suspension, no consistent downregulation of beta2M was observed after transplantation of stem cells encapsulated in alginate beads to generate a compartment where stem cells are protected from the host's natural killer cells. No expression of human genes was observed after transplantation of human cord blood derived mononuclear cells (MNC) that were used as a negative control. In conclusion, we have shown that human cord blood somatic stem cells survive and are reprogrammed after transplantation into mouse livers, although a complete transdifferentiation to hepatocytes did not occur within 7 days, since some marker genes (GATA4 and alpha-fetoprotein) were still negative. Switching off expression of beta2M may be part of an intriguing and novel mechanism explaining why stem cells escape the host's immune system.     

Kinetic studies on the aggregation of Aspergillus niger conidia

Morphology has a crucial effect on productivity and the supply of substrate for cultures of filamentous fungi. However, cultivation parameters leading to the desired morphology are often chosen empirically as the mechanisms governing the processes involved are usually unknown. For coagulating microorganisms like Aspergillus niger the morphological development is considered to start with the aggregation of conidia right after inoculation. To elucidate the mechanism of this process, kinetic studies were carried out using an in-line particle size analyzer. Based on the data obtained from these experiments a model for conidial aggregation is proposed in this article. It consists of two separate aggregation steps. The first one takes place immediately after inoculation, but only leads to a small decrease of total particle concentration. Most suspended conidia aggregate after a second aggregation step triggered by germination and hyphal growth. Aggregation velocity of this second phase is linearly dependent on the particle growth rate.     

Prognostic Influence of Pre-Operative C-Reactive Protein in Node-Negative Breast Cancer Patients

The importance of inflammation is increasingly noticed in cancer. The aim of this study was to analyze the prognostic influence of pre-operative serum C-reactive protein (CRP) in a cohort of 148 lymph node-negative breast cancer patients. The prognostic significance of CRP level for disease-free survival (DFS), metastasis-free survival (MFS) and overall survival (OS) was evaluated using univariate and multivariate Cox regression, also including information on age at diagnosis, tumor size, tumor grade, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status, proliferation index (Ki67) and molecular subtype, as well as an assessment of the presence of necrosis and inflammation in the tumor tissue. Univariate analysis showed that CRP, as a continuous variable, was significantly associated with DFS (P = 0.002, hazard ratio [HR]  = 1.04, 95% confidence interval [CI]  = 1.02–1.07) and OS (P = 0.036, HR  = 1.03, 95% CI  = 1.00–1.06), whereas a trend was observed for MFS (P = 0.111). In the multivariate analysis, CRP retained its significance for DFS (P = 0.033, HR  = 1.01, 95% CI  = 1.00–1.07) as well as OS (P = 0.023, HR  = 1.03, 95% CI  = 1.00–1.06), independent of established prognostic factors. Furthermore, large-scale gene expression analysis by Affymetrix HG-U133A arrays was performed for 72 (48.6%) patients. The correlations between serum CRP and gene expression levels in the corresponding carcinoma of the breast were assessed using Spearman''s rank correlation, controlled for false-discovery rate. No significant correlation was observed between CRP level and gene expression indicative of an ongoing local inflammatory process. In summary, pre-operatively elevated CRP levels at the time of diagnosis were associated with shorter DFS and OS independent of established prognostic factors in node-negative breast cancer, supporting a possible link between inflammation and prognosis in breast cancer.