How Free Swimming Fosters the Locomotion of a Purely Oscillating Fish-like Body.

The recoil motions in free swimming, given by lateral and angular rigid motions due to the interaction with the surrounding water, are of great importance for a correct evaluation of both the forward locomotion speed and efficiency of a fish-like body. Their contribution is essential for calculating the actual movements of the body rear end whose prominent influence on the generation of the proper body deformation was established a long time ago. In particular, the recoil motions are found here to promote a dramatic improvement of the performance when damaged fishes, namely for a partial functionality of the tail or even for its complete loss, are considered.

Wave dispersion in moderate channel turbulence.

We study channel turbulence by interpreting its vorticity as a random sea of ocean wave packet analogues. In particular, we investigate the ocean-like properties of vortical packets applying stochastic methods developed for oceanic fields. Taylor's hypothesis of frozen eddies does not hold when turbulence is not weak, and vortical packets change shape as they are advected by the mean flow, altering their own speed.

The fish ability to accelerate and suddenly turn in fast maneuvers.

Velocity burst and quick turning are performed by fish during fast maneuvers which might be essential to their survival along pray-predator encounters. The parameters to evaluate these truly unsteady motions are totally different from the ones for cruising gaits since a very large acceleration, up to several times the gravity, and an extreme turning capability, in less than one body length, are now the primary requests. Such impressive performances, still poorly understood, are not common to other living beings and are clearly related to the interaction with the aquatic environment.

The performance of a flapping foil for a self-propelled fishlike body.

Several fish species propel by oscillating the tail, while the remaining part of the body essentially contributes to the overall drag. Since in this case thrust and drag are in a way separable, most attention was focused on the study of propulsive efficiency for flapping foils under a prescribed stream. We claim here that the swimming performance should be evaluated, as for undulating fish whose drag and thrust are severely entangled, by turning to self-propelled locomotion to find the proper speed and the cost of transport for a given fishlike body.

[The CROFF pavilion at the Policlinico Hospital in Milan: the beginnings].

This article collects the personal stories of the young doctors who in the early sixties contributed to the birth and development of the Croff pavilion at the Policlinico Hospital in Milan. Inaugurated on October 19, 1964, this has been the first institute in Italy entirely devoted to patients with kidney diseases. Since its inception, it has significantly contributed to the progress of nephrology thanks to important and pioneering investigations in the main fields of our specialty, which still continue nowadays.

On the feasibility of the Rayleigh cycle for dynamic soaring trajectories.

Dynamic soaring is a flight technique used by albatrosses and other birds to cover large distances without the expenditure of energy, which is extracted from the available wind conditions, as brightly perceived five centuries ago by Leonardo da Vinci. Closed dynamic soaring trajectories use spatial variations of wind speed to travel, in principle, indefinitely over a prescribed area. The application of the concept of closed dynamic soaring trajectories to aerial vehicles, such as UAVs, may provide a solution to improve the endurance in certain missions.

Erdheim-Chester disease: from palliative care to targeted treatment.

Erdheim-Chester disease (ECD) is a life-threatening multi-systemic non-Langerhans histiocytosis with cardiovascular complications as the leading cause of death. ECD affects the kidneys in up to 30% of cases, with fibrotic tissue deposition in the perirenal fat and renal hilum. Diagnosis is usually based on histological analysis of the pathologic tissue, which typically shows xanthogranulomatous infiltrates of foamy CD68+/CD1a- histiocytes surrounded by fibrosis.

Neurological counterparts of hyponatremia: pathological mechanisms and clinical manifestations.

Hyponatremia, defined as a serum sodium concentration <135 mEq/L, represents the most frequent electrolyte disorder in older hospitalized patients. Early recognition of hyponatremia is mandatory, since it represents an independent risk factor that increases hospital mortality by 40 %. Delayed correction of hyponatremia may worsen brain edema, resulting in different degrees of neural damage.

Improvement of Erdheim-Chester disease-related renal failure after treatment with anakinra.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterized by infiltrates of lipid-laden CD68(+)/CD1a(-) histiocytes, affecting heart, lungs, central nervous system, and bones. Kidney and adjacent structures can also be affected, leading to renal failure in about 30% of cases. The diagnosis is challenging, and treatment is generally based on administration of interferon-alpha (IFNα), but preliminary results also showed the therapeutic efficacy of anakinra, an antagonist of the receptor of interleukin-1 (IL-1).

Renal transplantation in elderly patients. How to select the candidates to the waiting list?

Today, old age does not represent a formal contraindication to kidney transplantation. Rather, there is evidence that in elderly patients renal transplantation offers longer life expectancy and better quality of life in comparison with dialysis. Yet, the results of renal transplantation in recipients older than 65years are inferior to those observed in younger adults, death with functioning graft representing a major cause of failure.

The dialysis scenario in patients with systemic lupus erythematosus.

Although prognosis of lupus nephritis has improved over time, a substantial amount of lupus patients still reach end-stage renal disease and require dialysis. Treatment of these patients can be challenging, since the disease poses a number of problems that can portend a poor prognosis, such as infections, lupus reactivations, vascular access thrombosis and cardiovascular complications. Consensus is lacking among investigators about the real incidence of these complications and related diagnosis and treatment.

The humoral pattern recognition molecule PTX3 is a key component of innate immunity against urinary tract infection.

Immunity in the urinary tract has distinct and poorly understood pathophysiological characteristics and urinary tract infections (UTIs) are important causes of morbidity and mortality. We investigated the role of the soluble pattern recognition molecule pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, in UTIs. PTX3-deficient mice showed defective control of UTIs and exacerbated inflammation.

Renal dysfunction in acute congestive heart failure: a common problem for cardiologists and nephrologists.

The term acute heart failure (AHF) refers to a clinical syndrome with typical symptoms and signs, in which a structural or functional heart abnormality leads to defective oxygen delivery. The term cardiorenal syndrome has been proposed to outline the strict interplay between cardiac and renal function. In the setting of acute cardiac decompensation, acute kidney injury (AKI) is generally referred to as cardiorenal syndrome type 1.

Current and emerging treatments for idiopathic focal and segmental glomerulosclerosis in adults.

Idiopathic focal and segmental glomerular sclerosis is a frequent cause of nephrotic syndrome and end-stage renal disease. The pathogenesis is still unknown, although the body of evidence suggests that focal and segmental glomerular sclerosis is caused by a not clearly identified circulating factor that alters the permselectivity of the glomerular barrier. Proteinuria is followed by podocyte injury.

Education and counseling of renal transplant recipients.

A large number of factors can influence the clinical outcome of kidney transplant recipients, but the active role of the patient to prevent the possible complications related to transplant and its treatment is often neglected. Poor adherence to prescriptions is frequent in transplant recipients and represents a major contributor to the development of graft failure, cardiovascular disease, infection and/or malignancy. Smoking can render the patient more susceptible to cancer, cardiovascular disease and infection, and can also impair renal allograft function.

Proteinuria after kidney transplantation.

The prevalence of proteinuria at 1 year after renal transplantation ranges between 11% and 45% and is even higher in patients treated with inhibitors of the mammalian target of rapamycin (mTOR). Two main mechanisms can lead to proteinuria: an inadequate reabsorption of small proteins from proximal tubular cells damaged by ischemia-reperfusion injury, rejection, or toxic agents (tubular proteinuria) or an increased passage of albumin and/or protein with higher molecular weight (MW) because of a disruption of glomerular barrier caused by recurrent or de novo glomerulonephritis, transplant glomerulopathy, chronic rejection, or CNI toxicity (glomerular proteinuria). Proteinuric patients have worse patient and graft survival rates in comparison to non proteinuric patients.

Syndrome of inappropriate secretion of antidiuretic hormone in traumatic brain injury: when tolvaptan becomes a life saving drug.

Objective: To outline the role of a new drug, tolvaptan, in treating severe and chronic hyponatraemia. Tolvaptan decreases aquaporin expression in renal collecting ducts, by inhibiting antidiuretic hormone (ADH)-V2 receptors, to promote free water clearance. Given its mechanism of action, this drug seems the ideal treatment for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) when the osmotic imbalance leads to life threatening complications.

Chyluria associated with nephrotic-range proteinuria: pathophysiology, clinical picture and therapeutic options.

Chyluria denotes the urinary excretion of chyle, which is a lymphatic fluid rich in chylomicrons. Chyle flows from the intestinal lacteals to the left subclavian vein through the thoracic duct. When an abnormal connection between these structures and the urinary tract develops, chyluria appears.

Plasma pentraxin-3 as a marker of bioincompatibility in hemodialysis patients.

Introduction: Hemodialysis (HD)-induced inflammation has a pathogenetic role in patients with end-stage renal disease (ESRD). The aim of the present study was to assess whether pentraxin-3 (PTX3) could be a reliable biomarker of HD-induced inflammation and of membrane biocompatibility.

Methods: We prospectively enrolled 31 HD patients.

Looking at appearance of urine before performing a renal biopsy in nephrotic syndrome.

Chyluria results from an abnormal connection between lymphatic bed and urinary tract, causing lymph leakage into the urine. The clinical picture often begins with the appearance of cloudy, milky urines accompanied by monolateral flank pain, malnutrition, weight loss and weakness. We report a case of chyluria that occurred in a young woman who was referred to our unit for nephrotic-range proteinuria.

Hypertension in kidney transplant recipients.

Arterial hypertension is frequently observed in renal transplant recipients. Its pathogenesis is multifactorial in most cases. Calcineurin inhibitors (CNI) can increase peripheral vascular resistance by inducing arteriolar vasoconstriction and can cause extracellular fluid expansion by reducing the glomerular filtration rate (GFR), activating the renin-angiotensin system (RAS), and by inactivating the atrial natriuretic peptide.

CNS involvement and treatment with interferon-α are independent prognostic factors in Erdheim-Chester disease: a multicenter survival analysis of 53 patients.

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans histiocytosis, with noncodified therapeutic management and high mortality. No treatment has yet been shown to improve survival in these patients. We conducted a multicenter prospective observational cohort study to assess whether extraskeletal manifestations and interferon-α treatment would influence survival in a large cohort of ECD patients.

Life-threatening hypercalcemia in patients with rhabdomyolysis-induced oliguric acute renal failure.

Background: In a third of patients presenting with rhabdomyolysis-induced acute renal failure (ARF), a biphasic plasma calcium profile may occur.

Methods: We report a case of rhabdomyolysis-induced ARF presenting hypocalcemia during oliguria, followed by a severe hypercalcemia in the polyuric phase. A hypocalcemia-induced acute increase of plasma parathyroid hormone in the early stage of ARF was followed by a down-regulation of parathyroid hormone, 1,25(OH)2 vitamin D and 25(OH) vitamin D during the renal function recovery, associated with an acute hypercalcemia.