Antihypertensive drugs, dietary salt, and renal protection: how low should you go and with which therapy?

Although it is clear that hypertension accelerates the rate of progression of most forms of chronic renal disease, many unanswered questions remain concerning how to optimally preserve kidney function in patients with hypertension and renal insufficiency. The mechanisms by which hypertension accelerates progression of renal disease have been extensively studied in experimental models. Glomerular capillary hypertension, consequent to an increase in systemic blood pressure combined with a reduction in preglomerular resistance and/or an increase in postglomerular resistance, results in increased hydraulic stress to the glomerular capillary wall. This and other mechanisms result in the release of growth-promoting cytokines and soluble mediators of fibrosis that stimulate cellular proliferation and matrix accumulation, ultimately leading to glomerular sclerosis and interstitial fibrosis. Almost without exception, studies in animals demonstrate that blood pressure reduction reduces the rate of progression of experimental renal disease. Angiotensin-converting enzyme inhibitors and, possibly, calcium antagonists may have a therapeutic advantage compared with other antihypertensive drugs in preventing kidney damage. This has been linked to both blood pressure-dependent and -independent actions. However, most experimental studies have failed to reduce blood pressure to a level sufficient to establish the clinical relevance of potential blood pressure-independent effects. Experimental studies comparing various types of antihypertensive drugs in which a mean arterial pressure (MAP) of approximately 92 mm Hg is achieved are necessary to determine whether clinically important differences in the effects of these drugs on the rate of progression of renal disease exist. Clinical experience with high blood pressure and kidney disease in humans suggests that the risk of developing hypertension-associated renal disease is a continuous variable across the entire range of systolic and diastolic blood pressures. Logically, optimal protection of kidney function may therefore be a continuous function of declining systemic blood pressure. Consistent with this view, recent clinical trials suggest that reducing MAP to 92 mm Hg, corresponding to a blood pressure reading of 125/75 mm Hg, provides more optimal stabilization of renal function in patients with nondiabetic proteinuric kidney disease (>1 g/d) compared with more conventional therapy with a blood pressure goal of 140/90 mm Hg (MAP 107 mm Hg). Clinical trials in patients with diabetes mellitus and renal insufficiency also demonstrate the benefits of reducing blood pressure to approximately 95 mm Hg MAP. Dietary salt consumption may be another important variable affecting the rate of progression of renal disease due to both direct, salt-dependent effects on renal growth and the action of decreased salt intake to augment the antihypertensive and antiproteinuric properties of many drugs. The precise role of alterations in dietary salt consumption on progression of renal disease directly as well as on the effectiveness of various antihypertensive drugs has yet to be examined in clinical trials.     

Anti-desmoglein 1 antibodies in healthy related and unrelated subjects and patients with pemphigus foliaceus in endemic and non-endemic areas from Tunisia

Background  Pemphigus foliaceus is an autoimmune blistering skin disease characterized by the production of pathogenic IgG autoantibodies directed against desmoglein 1.
Aim  To determine the prevalence of anti-desmoglein 1 antibodies in healthy subjects and their distribution in the different regions of Tunisia and to better identify endemic areas of pemphigus foliaceus.
Methods  We tested, by enzyme-linked immunoserbent assay, sera of 270 normal subjects recruited from different Tunisian areas and 203 related healthy relatives to 90 Tunisian pemphigus foliaceus patients.
Results  Seventy-six patients (84.4%), 20 healthy controls (7.4%), and 32 relatives (15.76%) had anti-desmoglein 1 antibodies. In southern regions where pemphigus foliaceus is associated with a significant sex ratio imbalance (9 female : 1 male in the south vs. 2.3 : 1 in the north) and a lower mean age of disease onset (33.5 in the south vs. 45 years in the north), a higher prevalence of anti-desmoglein 1 antibodies in healthy controls was observed (9.23% vs. 5.71% in the north). Interestingly, the highest prevalence of anti-desmoglein 1 antibodies in healthy relatives (up to 22%) was observed in the most rural southern localities. More than half anti-desmoglein 1–positive healthy controls were living in rural conditions with farming as occupation, which suggests that this activity may expose the subjects to particular environmental conditions.
Conclusion  These results show that the endemic features of Tunisian pemphigus foliaceus are focused in these southern areas more than in other areas and that both environmental and genetic factors contribute to the disease.

Conflicts of interest

None declared.     

Geometry and landmark representation by pigeons: evidence for species‐differences in the hemispheric organization of spatial information processing?

In this study, we investigated how pigeons ( Columba livia ) represent environmental geometry and landmark information. Birds learned to locate the centre of a square arena by means of geometric cues alone, or by means of both geometric and landmark cues. By manipulating the type of information available at training and testing, we assessed which cues the birds had encoded, and through the use of monocular occlusion we examined how the information was represented by the two brain hemispheres. Our results show that both brain hemispheres encoded geometric and landmark information. During all viewing conditions, the geometric representation was based mainly on an absolute metric for distance. The relative use of geometry and landmarks was experience dependent. With both brain hemispheres available birds relied, to a greater degree, on geometric information and used it in a more integrated way than with either hemisphere alone. Overall, our findings show a different pattern for the hemispheric encoding of geometric and landmark information by the pigeon than that previously reported for the domestic chick. Our results suggest that the organization of spatial information processing in the left and right brain hemispheres of birds may be more diverse than what is currently known.     

Inaccuracies associated with the automated measurement of mean cell hemoglobin concentration in dehydrated cells

Because of discrepancies between electronically and manually measured values of mean cell hemoglobin concentration (MCHC) encountered in studies of pathologic red cells, we studied the effect of cell water content on MCHC measurements by both methods. A series of red cell samples with varying water contents (54%-164% normal) were prepared from normal cells using the antibiotic nystatin. MCHC was then measured, using the microhematocrit centrifuge and three different electronic cell counters in common laboratory use. For MCHC values above 36 g/dl as measured by the spun hematocrit method, all three electronic counters under estimmated the MCHC, with increasing error as the true MCHC increased. For MCHC values below 30 g/dl, the values from two conductivity based instruments agreed with those from the spun hematocrit method, whereas one instrument based on light scattering overestimated the MCHC. These results indicate that inaccuracies in the measured mean cell volume (MCV) of dehydrated or otherwise undeformable cells may lead to spurious values for MCHC when electronic cell counters are used.     

The mental health of young people in Australia: key findings from the child and adolescent component of the national survey of mental health and well-being

OBJECTIVE: To identify the prevalence of three mental disorders (Depressive Disorder, Conduct Disorder and Attention-Deficit/Hyperactivity Disorder), the prevalence of mental health problems, the health-related quality of life of those with problems, and patterns of service utilisation of those with and without mental health problems, among 4-17-year-olds in Australia. To identify rates of health-risk behaviours among adolescents with mental health problems. METHOD: The mental disorders were assessed using the parent-version of the Diagnostic Interview Schedule for Children Version IV. Parents completed the Child Behaviour Checklist to identify mental health problems and standard questionnaires to assess health-related quality of life and service use. The Youth Risk Behaviour Questionnaire completed by adolescents was employed to identify health-risk behaviours. RESULTS: Fourteen percent of children and adolescents were identified as having mental health problems. Many of those with mental health problems had problems in other areas of their lives and were at increased risk for suicidal behaviour. Only 25% of those with mental health problems had attended a professional service during the six months prior to the survey. CONCLUSION: Child and adolescent mental health problems are an important public health problem in Australia. The appropriate balance between funding provided for clinical interventions focusing on individual children and families and funding for interventions that focus on populations, requires careful study. The latter are an essential component of any strategy to reduce mental health problems as the high prevalence of problems makes it unlikely that individual care will ever be available for all those needing help. Clinical and population health interventions must take into account the comorbid problems experienced by children with mental disorders.     

一体化PET/MR检查临床护理操作规范(2017版)

一体化PET/MR检查护理规范是关于PET/MR检查过程中对于护理人员的工作要求,包括检查前准备、注射药物护理、检查时护理、检查后护理、对比剂不良反应处理和个人辐射防护。旨在为核医学科护士在临床PET/MR检查中提供实用且行之有效的处理操作规范。