Surface Improvement and Dust Palliation of Unpaved Secondary Roads and Streets, HR-151, 1973

As of December 31, 1970 there were 57,270 miles of Local Secondary roads and 32,958 miles of Farm to Market roads in the Iowa secondary road system. The Local Secondary system carried a traffic load of 2,714,180 daily vehicle miles, accounting for 32% of all traffic in the secondary system. For all Local Secondary roads having some form of surfacing, 98% were surfaced with gravel or crushed stone. During the 1970 construction year 335 miles of surfaced roads were constructed in the Local Secondary system with 78% being surfaced with gravel or crushed stone. The total maintenance expenditure for all secondary roads in Iowa during 1970 amounted to $40,086,091. Of this, 42%, or $17,020,332, was spent for aggregate replacement on existing gravel or crushed stone roads with an additional 31% ($12,604,456) being spent on maintenance other than resurfacing. This amounts to 73% of the total maintenance budget and are the largest two maintenance expenditure items out of a list of 10 ranging from bridges to drainage assessments. The next largest item was 7%, for maintenance of existing flexible bases. Three concurrent phases of study were included in this project: (1) laboratory screenings studies of various additives thought to have potential for long-lasting dust palliation, soil additive strength, durability, and additive retention potential; (2) test road construction using those additives that indicated promise for performance-serviceability usage; and (3) observations and tests of constructed sections for evaluation of the additive's contribution to performance and serviceability as well as the relationship to initial costs.

Surface Improvement and Dust Palliation of Unpaved Secondary Roads and Streets, Progress Report, HR-151, 1971

A combined study of dust control and low-cost surface improvements of soil and aggregate materials for immediate (and intermediate) use as a treated surface course is being conducted in three concurrent phases: (1) laboratory screening of various additives thought to have potential for long-lasting dust palliation, soil-additive strength, durability, and additive retention potential; (2) test road construction, using those additives from the screening studies that indicate promise for performance and serviceability; and (3) observation and tests of constructed sections for evaluation of the additive's contribution to performance and serviceability as well as relationship to initial costs. A brief review is presented of the problem, some methods of measuring it, previously adopted approaches to it, project field tests and a portion of the results thus far, and portions of the laboratory work accomplished in the screening studies.

Blood pressure, cardiac, and renal responses to salt and deoxycorticosterone acetate in mice: role of Renin genes.

Several studies have demonstrated that mice are polymorphic for the number of renin genes, with some inbred strains harboring one gene (Ren-1(c)) and other strains containing two genes (Ren-1(d) and Ren-2). In this study, the effects of 1% salt and deoxycorticosterone acetate (DOCA)/salt were investigated in one- and two-renin gene mice, for elucidation of the role of renin in the modulation of BP, cardiac, and renal responses to salt and DOCA. The results demonstrated that, under baseline conditions, mice with two renin genes exhibited 10-fold higher plasma renin activity, 100-fold higher plasma renin concentrations, elevated BP (which was angiotensin II-dependent), and an increased cardiac weight index, compared with one-renin gene mice (all P < 0.01). The presence of two renin genes markedly increased the BP, cardiac, and renal responses to salt. The number of renin genes also modulated the responses to DOCA/salt. In one-renin gene mice, DOCA/salt induced significant renal and cardiac hypertrophy (P < 0.01) even in the absence of any increase in BP. Treatment with losartan, an angiotensin II AT(1) receptor antagonist, decreased BP in two-renin gene mice but not in one-renin gene mice. However, losartan prevented the development of cardiac hypertrophy in both groups of mice. In conclusion, these data demonstrate that renin genes are important determinants of BP and of the responses to salt and DOCA in mice. The results confirm that the Ren-2 gene, which controls renin production mainly in the submaxillary gland, is physiologically active in mice and is not subject to the usual negative feedback control. Finally, these data provide further evidence that mineralocorticoids promote cardiac hypertrophy even in the absence of BP changes. This hypertrophic process is mediated in part by the activation of angiotensin II AT(1) receptors.

Quelles applications raisonnables pour l'anticoagulation régionale au citrate en épuration extrarénale [What reasonable applications for regional citrate anticoagulation in renal replacement therapy?].

Regional citrate anticoagulation of the extracorporeal circuits (CRA) experienced considerable growth over the past decade. This development is partly explained by the significant progresses made in the field of bioengineering. These allow a secure administration of citrate, while an increasing availability of ionized calcium measurement at the bedside allows reactivity in monitoring the treatment. An increasing severity of the medical condition of patients requiring blood purification treatment gives more contrast to the profile of patient who may benefit from a CRA. If some methods of renal replacement therapy are well suited to this mode of anticoagulation, others are, to date, only at the stage of development and are applied under close medical supervision.

Effect of dark chocolate on renal tissue oxygenation as measured by BOLD-MRI in healthy volunteers.

Background: Cocoa is rich in flavonoids, has anti-oxidative properties and increases the bioavailability of nitric oxide (NO). Adequate renal tissue oxygenation is crucial for the maintenance of renal function. The goal of this study was to investigate the effect of cocoa-rich dark chocolate (DC) on renal tissue oxygenation in humans, as compared to flavonoid-poor white chocolate (WC). Methods: Ten healthy volunteers with preserved kidney function (mean age ± SD 35 ± 12 years, 70% women, BMI 21 ± 3 kg/m2) underwent blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) before and 2 hours after the ingestion of 1 g/kg of DC (70% cocoa). Renal tissue oxygenation was determined by the measurement of R2* maps on 4 coronal slices covering both kidneys. The mean R2* (= 1/T2*) values in the medulla and cortex were calculated, a low R2* indicating high tissue oxygenation. Eight participants also underwent BOLD-MRI at least 1 week later, before and 2 hours after the intake of 1 g/kg WC. Results: The mean medullary R2* was lower after DC intake compared to baseline (28.2 ± 1.3 s-1 vs. 29.6 ± 1.3 s-1, p = 0.04), whereas cortical and medullary R2* values did not change after WC intake. The change in medullary R2* correlated with the level of circulating (epi)catechines, metabolites of flavonoids (r = 0.74, p = 0.037), and was independent of plasma renin activity. Conclusion: This study suggests for the first time an increase of renal medullary oxygenation after intake of dark chocolate. Whether this is linked to flavonoid-induced changes in renal perfusion or oxygen consumption, and whether cocoa has potentially renoprotective properties, merits further study.

Secondary Ion Mass Spectrometry (SIMS): principles and applications

This article outlines the basis of the technique and shows some examples of applications in order to exhibit the expectations of this technique invaried scientific fields.

R commands secondary production

R commands to calculate the secondary production estimates using the size-frequency method after Hynes and Coleman (1968), Benke (1979) and Huryn (1996).

Protéinurie orthostatique et phénomène de compression de la veine rénale gauche (nutcracker syndrome) [Orthostatic proteinuria and compression of the left renal vein (nutcracker syndrome)]

INTRODUCTION: The pathogenic mechanism of orthostatic proteinuria has not yet been clearly established. OBSERVATION: In a tall, thin, 21 year-old man, isolated proteinuria was discovered during an urological control conducted one year after a bilateral orchidopexy following left testicular torsion. Proteinuria was orthostatic. Doppler examination of the kidney revealed an entrapment of the left renal vein (nutcracker phenomenon-NCP). COMMENTS: An NCP was diagnosed in a young patient presenting with orthostatic proteinuria. By provoking modifications in intraglomerular haemodynamics, the NCP may, in nearly half of the cases, be at the origin of orthostatic proteinuria. Doppler examination is the diagnostic method of choice in the screening for NCP.

Nouveaux aspects de la prise en charge de l'hypertension artérielle chez le patient insuffisant rénal chronique [New aspects of hypertension management in patients with chronic kidney disease].

Hypertension is a frequent finding in patients with chronic kidney disease. Whether primary or secondary to renal disease, hypertension remains an important risk factory for the progression of chronic kidney disease and the occurrence of cardiovascular events. The objective of this paper is to review different treatment strategies in hypertensive CKD patients, with the exclusion of patients with renal replacement therapy such as dialysis or renal transplantation.

Histones from dying renal cells aggravate kidney injury via TLR2 and TLR4.

In AKI, dying renal cells release intracellular molecules that stimulate immune cells to secrete proinflammatory cytokines, which trigger leukocyte recruitment and renal inflammation. Whether the release of histones, specifically, from dying cells contributes to the inflammation of AKI is unknown. In this study, we found that dying tubular epithelial cells released histones into the extracellular space, which directly interacted with Toll-like receptor (TLR)-2 (TLR2) and TLR4 to induce MyD88, NF-κB, and mitogen activated protein kinase signaling. Extracellular histones also had directly toxic effects on renal endothelial cells and tubular epithelial cells in vitro. In addition, direct injection of histones into the renal arteries of mice demonstrated that histones induce leukocyte recruitment, microvascular vascular leakage, renal inflammation, and structural features of AKI in a TLR2/TLR4-dependent manner. Antihistone IgG, which neutralizes the immunostimulatory effects of histones, suppressed intrarenal inflammation, neutrophil infiltration, and tubular cell necrosis and improved excretory renal function. In summary, the release of histones from dying cells aggravates AKI via both its direct toxicity to renal cells and its proinflammatory effects. Because the induction of proinflammatory cytokines in dendritic cells requires TLR2 and TLR4, these results support the concept that renal damage triggers an innate immune response, which contributes to the pathogenesis of AKI.

Scoring system for renal pathology in Fabry disease: report of the international study group of fabry nephropathy (ISGFN).

BACKGROUND: In Fabry nephropathy, alpha-galactosidase deficiency leads to accumulation of glycosphingolipids in all kidney cell types, proteinuria and progressive loss of kidney function. METHODS: An international working group of nephrologists from 11 Fabry centres identified adult Fabry patients, and pathologists scored histologic changes on renal biopsies. A standardized scoring system was developed with a modified Delphi technique assessing 59 Fabry nephropathy cases. Each case was scored independently of clinical information by at least three pathologists with an average final score reported. RESULTS: We assessed 35 males (mean age 36.4 years) and 24 females (43.9 years) who mostly had clinically mild Fabry nephropathy. The average serum creatinine was 1.3 mg/dl (114.9 micromol/l); estimated glomerular filtration rate was 81.7 ml/min/1.73 m(2) and urine protein to creatinine ratio was 1.08 g/g (122.0 mg/mmol). Males had greater podocyte vacuolization on light microscopy (mean score) and glycosphingolipid inclusions on semi-thin sections than females. Males also had significantly more proximal tubule, peritubular capillary and vascular intimal inclusions. Arteriolar hyalinosis was similar, but females had significantly more arterial hyalinosis. Chronic kidney disease stage correlated with arterial and glomerular sclerosis scores. Significant changes, including segmental and global sclerosis, and interstitial fibrosis were seen even in patients with stage 1-2 chronic kidney disease with minimal proteinuria. CONCLUSIONS: The development of a standardized scoring system of both disease-specific lesions, i.e. lipid deposition related, and general lesions of progression, i.e. fibrosis and sclerosis, showed a spectrum of histologic appearances even in early clinical stage of Fabry nephropathy. These findings support the role of kidney biopsy in the baseline evaluation of Fabry nephropathy, even with mild clinical disease. The scoring system will be useful for longitudinal assessment of prognosis and responses to therapy for Fabry nephropathy.

Dénervation rénale pour le traitement de l'hypertension artérielle résistante: proposition pour une attitude multidisciplinaire commune [Renal denervation in resistant hypertension: proposal for a common multidisciplinary attitude].

The prevalence of resistant hypertension ranges between 5-30%. Patients with resistant hypertension are at increased risk of cardiovascular events. Radiofrequency renal denervation is a recent and promising technique that can be used in the setting of resistant hypertension. However, long-term safety and efficacy data are lacking and evidence to use this procedure outside the strict setting of resistant hypertension is missing. The aim of the article is to propose a common work-up for nephrologists, hypertensiologists, cardiologists and interventional radiologists in order to avoid inappropriate selection of patients and a possible misuse of this procedure.

Circadian regulation of renal function and potential role in hypertension.

PURPOSE OF REVIEW: Previous studies have shown that a variety of specific renal functions exhibit circadian oscillations. This review aims to provide an update on the molecular mechanisms underlying circadian rhythms in the kidney, and to discuss how dysregulation of circadian rhythms can interfere with kidney function. RECENT FINDINGS: The molecular mechanism responsible for generating and maintaining circadian rhythms has been unraveled in great detail. This mechanism, known as the circadian clock, drives circadian oscillation in expression levels of a large number of renal mRNA transcripts. Several proteins critically involved in renal homeostatic functions have been shown to exhibit significant circadian oscillation in their expression levels or in their posttranslational modifications. In transgenic mouse models, disruption of circadian clock activity results in dramatic changes in the circadian pattern of urinary sodium and potassium excretion and causes significant changes in arterial blood pressure. A growing amount of evidence suggests that dysregulation of circadian rhythms is associated with the development of hypertension and accelerated progression of chronic kidney disease and cardiovascular disease in humans. Chronotherapy studies have shown that the efficacy of antihypertensive medication is greatly dependent on the circadian time of drug administration. SUMMARY: Recent research points to the major role of circadian rhythms in renal function and in control of blood pressure.