Nenatal drug induced nephrotoxicity : old and next generation biomarkers for early detection and management of neonatal drug-induced nephrotoxicity, with special emphasis on uNGAL and on metabolomics.

For a long time, nephrotoxicity has been definitively defined as renal injury or dysfunction that arises as a direct or indirect result of exposure to drugs and industrial or environmental chemicals. There are a number of inherent difficulties in diagnostic procedures for toxic nephropathy, which include the absence of standard diagnostic criteria and the inability to relate exposure to a given agent and the observed effect. Critically ill newborns represent a high risk population for developing toxic nephropathy because of incomplete maturation of the kidney; furthermore, they are often treated with a combination of various therapeutic agents, each of them potentially inducing renal tissue injury. Antibiotics, antifungals, and non-steroidal antiiflammatory drugs (NSAIDs) can induce nephrotoxic damage by several, concomitant mechanisms of action on different segments of the nephron. The most common clinical feature following a nephrotoxic effect is acute kidney injury (AKI) which, in turn, comprises a spectrum of severe tissue damages along the nephron, leading to an abrupt decline in renal function. Because early stages of toxic nephropathy are characterized by very few specific clinical signs and symptoms, there is the urgent need to investigate new biomarkers for predicting nephrotoxicity and localizing the injury to a specific nephron site, in order to reduce the risk of acute renal injury and/or acute tubular necrosis. The most promising biomarker for the early assessment of kidney injury and damage is neutrophil gelatinase-associated lipocalin (NGAL). NGAL can be easily measured in urine by an automated analytical method, allowing its clinical use in emergency likewise creatinine. Considerable expectations in terms of improvement of the management of newborns developing drug-induced nephropaties derive from the clinical application of metabolomics.

Liposomal amphotericin B does not induce nephrotoxicity or renal function impairment in premature neonates.

BACKGROUND: Liposomal amphotericin B (LAMB) is frequently administered in NICU to preterm infants <1500 g at birth (VLBW) for treatment of systemic fungal infections (SFI). Concerns exist on safety and tolerability of such drug in patients who are at risk for renal function impairment due to their prematurity. AIM: To assess the occurrence of renal function impairment related to LAMB in a 10-year cohort of VLBW neonates treated with this drug. METHODS: Through database search of clinical charts, all VLBW neonates admitted to a 3(rd) level NICU in the years 1998-2007 and undergoing treatment with LAMB were identified. The occurrence of LAMB-attributable renal toxicity was investigated; infants withdrawn from treatment for development of adverse effects or toxicity were identified. RESULTS: In the study period, 71 of 792 admitted VLBW neonates (8.9%) underwent antifungal treatment with LAMB administered at the recommended dosages (3-to-5 mg/kg/day). Mean duration of treatment was 14 (±9) days, mean cumulative dose given was 58 (±25) mg/kg per infant. Renal compromise, defined as hypokalaemia, and/or elevated creatinine serum levels, and/or decreased urine output, occurred in 2 of 71 (2.8%) treated patients, by 5 (±3) mean days after treatment initiation. In both patients LAMB was withdrawn; renal function impairment was only mild and transient, and normal renal function was restored at discharge. No other significant adverse effects were recorded in any treated neonate. CONCLUSIONS: LAMB is generally safe and well tolerated in VLBW neonates. The occurrence of LAMB-related nephrotoxicity appears to be uncommon, mild and transient.

Acute nephrotoxicity of NSAID from the foetus to the adult.

NSAIDs are generally considered to be safe and well tolerated, but, even with the advent of selective COX-2 inhibitors, nephrotoxicity remains a concern. An impaired renal perfusion caused by the inhibition of prostaglandin synthesis is claimed like the more frequent cause of an acute renal failure due to NSAIDs, while a chronic interstitial nephritis or an analgesic nephropathy are believed the causes of a chronic renal failure. The real incidence of renal side effects of NSAIDs is still unclear and it differs between the age of the patients and the reports present in the literature. The occurrence of renal side effects following prenatal exposure to NSAIDs seems to be rare considering the large number of pregnant woman treated with indomethacin or other prostaglandin inhibitors. NSAID-related nephrotoxicity remains an important clinical problem in the newborns, in whom the functionally immature kidney may exert a significant effect on the disposition of the drugs. Instead, nephrotoxicity is a rare event in children and the risk is lower than adults. In healthy adult patients the incidence of renal adverse effects is very low, less than 1%. The risk increased with age. The elderly are at higher risk, and it is correlated at the presence of pretreatment renal disease, hypovolemia due to use of diuretics, diabetes, congestive heart failure or alteration of NSAID pharmacokinetics.

Metabolomics: the "new clinical chemistry" for personalized neonatal medicine.

Metabolomics is a new approach based on the systematic study of the full complement of metabolites in a biological sample. This technology consists of two sequential steps: (1) an experimental technique, based on mass spectrometry or nuclear magnetic resonance (NMR) spectroscopy, designed to profile low molecular weight compounds, and (2) multivariate data analysis. Metabolomic analysis of biofluids or tissues has been successfully used in the fields of physiology, diagnostics, functional genomics, pharmacology, toxicology and nutrition. Recent studies have evaluated how physiological variables or pathological conditions can affect metabolomic profiles of different biofluids in pediatric populations. Little is known about the overall metabolic status of the term and preterm neonate. On the other hand, the management of sick or preterm newborns might be improved if more information on perinatal/neonatal maturational processes and their metabolic background were available. At present, the use of metabolomics in Neonatology is still in the pioneering phase. Meaningful diagnostic information and simple, non-invasive collection techniques make urine a particularly suitable biofluid for metabolomic approach in neonatal medicine. Using NMR-based metabolomic analysis of urine, distinct metabolic patterns have been shown to be associated with different classes of gestational age in a population of preterm and term infants. Together with genomics and proteomics, metabolomics appears to be a promising tool in Neonatology for the monitoring of postnatal metabolic maturation, the identification of biomarkers as early predictors of outcome, the diagnosis and monitoring of various diseases and the "tailored" management of neonatal disorders.

Changes in urinary PGE2 after ibuprofen treatment in preterm infants with patent ductus arteriosus.

PURPOSE: To investigate changes in urinary PGE(2) after ibuprofen treatment in preterm infants with patent ductus arteriosus (PDA). METHODS: Twenty preterm infants with a hemodynamically significant PDA (gestational age, 28.6 +/- 2.3 weeks) and 20 controls (gestational age, 30.4 +/- 1.5 weeks) were prospectively enrolled at 48-72 h of life. After enrollment, the former underwent conventional ibuprofen-lysine treatment. At 48-72 h (T(0)) and 108-144 h of life (T(1)), urine samples were noninvasively collected in both groups to measure urinary PGE(2) concentrations (enzyme immunoassay method), and renal function was investigated. RESULTS: Urinary PGE(2) decreased significantly both in ibuprofen-treated patients (66.95 +/- 16.78 vs. 27.15 +/- 17.92 pg/mL, P < 0.001) and in controls (71.7 +/- 16.2 vs. 53.2 +/- 18.4 pg/mL, P < 0.001) from T(0) to T(1). However, urinary PGE(2) at T(1) was significantly lower (P < 0.001) in the ibuprofen group compared to the control group. Acute renal failure occurred in three ibuprofen-treated patients (15%). CONCLUSIONS: Ibuprofen markedly reduces (59.4%) urinary PGE(2) and may alter renal function in the newborn.

Immunoreactivity to glial cell line-derived neurotrophic factor and its receptors in the trout pancreas: a further endocrine-exocrine relationship?

Glial cell line-derived neurotrophic factor (GDNF) is a growth factor promoting the survival of several neuronal populations in the central, peripheral and autonomous nervous system. Outside the nervous system, GDNF functions as a morphogen in kidney development and regulates spermatogonial differentiation. GDNF exerts its roles by binding to glial cell line-derived neurotrophic factor receptor (GFR) a1, which forms a heterotetramic complex with rearranged during transfection (RET) proto-oncogene product, a tyrosine kinase receptor. In this study we report the presence of GDNF-, RET- and GFRa1-like immunoreactivity in the pancreas of juvenile trout. GDNF immunoreactivity was observed in the islet cells, while GFRa1- and RET- immunoreactivity was observed in the exocrine portion. These findings suggest a paracrine role of GDNF towards exocrine cells showing GDNF receptors GFRa1 and RET. The relationship could reflect physiological interactions, as previously indicated in mammalian pancreas, and/or a trophic role by endocrine cells on exocrine parenchyma, which shows a conspicuous increase during animal growth.

Circulating haemopoietic and endothelial progenitor cells are decreased in COPD.

Circulating CD34+ cells are haemopoietic progenitors that may play a role in tissue repair. No data are available on circulating progenitors in chronic obstructive pulmonary disease (COPD). Circulating CD34+ cells were studied in 18 patients with moderate-to-severe COPD (age: mean+/-sd 68+/-8 yrs; forced expiratory volume in one second: 48+/-12% predicted) and 12 controls, at rest and after endurance exercise. Plasma concentrations of haematopoietic growth factors (FMS-like tyrosine kinase 3 (Flt3) ligand, kit ligand), markers of hypoxia (vascular endothelial growth factor (VEGF)) and stimulators of angiogenesis (VEGF, hepatocyte growth factor (HGF)) and markers of systemic inflammation (tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8) were measured. Compared with the controls, the COPD patients showed a three-fold reduction in CD34+ cell counts (3.3+/-2.5 versus 10.3+/-4.2 cells.microL-1), and a 50% decrease in AC133+ cells. In the COPD patients, progenitor-derived haemopoietic and endothelial cell colonies were reduced by 30-50%. However, four COPD patients showed progenitor counts in the normal range associated with lower TNF-alpha levels. In the entire sample, CD34+ cell counts correlated with exercise capacity and severity of airflow obstruction. After endurance exercise, progenitor counts were unchanged, while plasma Flt3 ligand and VEGF only increased in the COPD patients. Plasma HGF levels were higher in the COPD patients compared with the controls and correlated inversely with the number of progenitor-derived colonies. In conclusion, circulating CD34+ cells and endothelial progenitors were decreased in chronic obstructive pulmonary disease patients and could be correlated with disease severity.

Acute encephalopathy associated with respiratory syncytial virus infections in childhood. A literature review.

Respiratory syncytial virus (RSV) has been described as the single most important virus causing acute respiratory infections, especially bronchiolitis and pneumonia, in children. The most severe infections affect the youngest infants and well-defined high-risk groups, including infants with a history of premature birth, and those with chronic lung disease, congenital heart disease, cystic fibrosis and immunodeficiency. It has been reported that approximately 1/3 of high-risk children hospitalized with RSV infection are admitted to the intensive care unit, while the need for mechanical ventilation and mortality rate are increased in infants with underlying cardiac disease or chronic lung disease. The majority of infants hospitalized for RSV lower respiratory tract infection develop one complication or more, which have an impact on hospital length of stay and costs. A relatively uncommon complication consisting of seizures and other neurologic abnormalities such as lethargy, irritability and abnormal tone has been sporadically reported in infants and children with RSV respiratory infection. A recent study first focused on the association between RSV bronchiolitis and an encephalopathic process occurring in the form of a seizures disorder. This transient neurologic complication seems to be frequently associated with an abnormal EEG pattern, but no anatomic brain damages have been shown. Little is known about the long-term neurodevelopmental outcomes of children developing RSV-related encephalopathy, so a prolonged period of neurologic follow up can be recommended.

Water and sodium imbalance in COPD patients.

Water retention and hyponatraemia are typically observed in the final stages of Chronic Obstructive Pulmonary Disease (COPD) and the onset of edema is a poor prognostic factor. For several years the pathogenesis of edema in COPD patients was attributed to heart impairment because of pulmonary hypertension, but the evidence that cardiac output is often adequate for the metabolic demands has suggested, since 1960, that the pathogenesis of edema in these patients would be correlated with gas exchange impairment and in particular with carbon dioxide (CO2) retention. The gas exchange impairment induces, in these patients several hormonal abnormalities: renin (Rn), angiotensin II (AnII), aldosterone (Ald), atrial natriuretic peptide (ANP), vasopressin (ADH) and endothelial factors are some of the factors involved. The systemic response to hypercapnia has the effect of reducing the renal blood flow and, as a result, increasing water and sodium retention with the final effect of edema and hyponatraemia. The aim of this brief review is to highlight the current knowledge on renal/hormonal abnormalities in COPD and their therapeutic implications.

Exercise physiology in COPD.

Multiple mechanisms contribute to exercise limitation in chronic obstructive pulmonary disease (COPD). The ability to increase ventilation during exercise is reduced; the more advanced the disease, the more impaired the exercise tolerance is. However, factors other than ventilatory limitation play an important role in reducing the exercise capacity in COPD. Data implicating peripheral muscle atrophy and muscle weakness as cofactors have been reported in individuals with advanced disease. At this stage daily activities are curtailed to avoid exertional respiratory discomfort. Recent studies have demonstrated that the muscle aerobic capacity of stable hypoxemic COPD patients is impaired; oxygen uptake (V'O2) kinetics and 31P magnetic resonance spectroscopy studies have shown that these patients rely heavily on non-aerobic energy sources even during moderate, sustained workloads. Finally, early occurrence of metabolic acidosis has been demonstrated in patients with mild to severe COPD during exercise. Inadequate tissue oxygenation appears to result from a defect in peripheral oxygen utilization rather than from a reduction in O2 bulk flow. Peripheral factors may include: a) impaired diffusive conductance for O2 between red cells and mitochondria; b) heterogeneous distribution of O2 bulk flow within the exercising muscle fibers; c) inertia of the oxidative processes at the cellular level; d) changes in distribution of muscle fibers, e) reduction in muscle aerobic enzymes; and f) poor nutritional status. Since muscle dysfunction has an important role in the development of exercise intolerance, physical rehabilitation is more and more used as part of the treatment of COPD. The aim of this review is to briefly discuss current views on the mechanisms responsible for the reduced ability to exercise and the rationale for exercise rehabilitation in COPD patients.

Skeletal muscle dysfunction in chronic obstructive pulmonary disease.

During the last decade evidence has been accumulated on the role of skeletal muscle dysfunction in reducing exercise capacity and affecting the quality of life of patients with chronic obstructive pulmonary disease (COPD). An appreciable body of research has helped to identify morphological and biochemical alterations, physiological consequences, and possible therapeutic interventions. There are, however, still many areas of uncertainty. For example it is not clear how much of the alterations are within the muscle itself or the consequence of the altered environment in which the muscle works. Similarly it is not clear how much of the impairment is simply due to aging and chronic inactivity. Another key issue is the possible additive effect of drugs often used in COPD patients, such as steroids, beta 2-agonist and cyclosporin. A specific additional layer of complexity comes from nutritional considerations and in particular loss of muscle mass which not infrequently accompanies severe disease and even greater exercise intolerance. Studies on the effects of training or other therapeutic interventions have shown that muscle dysfunction is partially reversible. There is, however, a clear need for studies based on cellular and molecular methods aimed to clarify the role of factors such as oxidative stress, inflammation and nutritional deficiencies on skeletal muscle structure and function. The focus of this review is to highlight the current knowledge on skeletal muscle dysfunction in COPD and briefly summarize the possible therapeutic implications.

VIP-like immunoreactivity in the intestinal tract of fish with different feeding habits.

We studied the distribution of vasoactive intestinal polypeptide immunoreactive (VIP-ir) cells and fibres in the intestine of three fish species with different feeding habits: the silver carp (Hypophthalmichthys molitrix), the goldfish (Carassius auratus), and the pumpkinseed sunfish (Lepomis gibbosus). Each species was divided into two groups: (1) fish fed once a day up until sacrifice and (2) fish fed once a day and then fasted three days before sacrifice. Immunoreactive endocrine cells and fibres were present in all three fish species. The immunoreactive cells were distributed along the entire intestinal mucosa of the carp and goldfish but were found only in the anterior intestine of the sunfish. The immunoreactive fibres were present along the entire intestinal wall, in the myenteric plexus, in the circular muscular layer, and in the connective tissue of the mucosa in all three fish species. No differences were found between the cells and fibres of normally-fed animals and the cells and fibres of fasted animals. The authors hypothesize that the different distributions of VIP-ir cells and fibres are related to the different contents of hard and indigestible matter of the fish food.

A water-vapour giga-maser in the active galaxy TXFS2226-184.

Active galactic nuclei are thought to be powered by gas falling into a massive black hole; the different types of active galaxy may arise because we view them through a thick torus of molecular gas at varying angles of inclination. One way to determine whether the black hole is surrounded by a torus, which would obscure the accretion disk around the black hole along certain lines of sight, is to search for water masers, as these exist only in regions with plentiful molecular gas. Since the first detection of an extra-galactic water maser in 1979, they have come to be associated primarily with active galaxies, and have even been used to probe the mass of the central engine. Here we report the detection of a water giga-maser in the radio galaxy TXFS2226-184. The strength of the emission supports a recently proposed theory of maser pumping that allows for even more powerful masers, which might be detectable at cosmological distances. Water masers may accordingly provide a way to determine distances to galaxies outside the usual distance ladder, providing an independent calibration of the Hubble constant.

[The effect of cadmium on the intestine of Carassius auratus]. / Influence du cadmium sur l'intestin de Carassius auratus.

The paper deals with the cadmium effects on the intestinal mucosa of adult Carassius auratus after 7, 14 and 40 days of exposure. After 7 days the mucosa becomes oedematous; the mucous cells show intensive secretion. The cells showing immunoreactivity for the Met- and Leu-enkephalin miss this feature. After 14 days these modifications diminish and after 40 days disappear completely and the mucosa gains its normal characteristics.

Serum lipoprotein pattern as modified in G6PD-deficient children during haemolytic anaemia induced by fava bean ingestion.

In the present study, plasma lipid concentrations were determined at different times after admission in sera from G6PD-deficient children during haemolytic crisis induced by fava bean ingestion. Reductions in total, LDL and HDL cholesterol were found in association with the maximum of bone marrow hyperplasia. A return towards normal values occurred with regression of the disease. No changes in other lipid parameters were observed. These data suggest that alterations of lipoprotein pattern, other than in experimental animals, are also present in humans with non-malignant proliferative processes. These changes appear to be a consequence of the disease, probably due to an increased utilization of cholesterol by proliferating cells.

[Immunohistochemical and ultrastructural study of endocrine cells from the pyloric region of the European mole (Talpa europaea)]. / Etude immuno-histochimique et ultrastructurale des cellules endocrines de la région pylorique chez la taupe européenne (Talpa europaea).

The distribution and the morphology of some endocrine cells (gastrin, somatostatin and 5-HT immunoreactive) in the pyloric region were studied in the Talpa europaea, an insectivore representing one of the most primitive living Eutherians. The immunohistochemical studies enabled us to identify and calculate the percentage of each cell type: the most numerous endocrine cells were gastrin immunoreactive; fairly numerous appeared somatostatin immunopositive; less numerous were 5-HT immunoreactive cells. While the ultrastructural observations let us describe four endocrine cell types: G cells producing gastrin, D cells containing somatostatin, EC cells of the gastric type producing 5-HT and D1 cells whose content is still unknown.

Polysaccharides as taste stimuli: their effect in the nucleus tractus solitarius of the rat.

Rats show a pronounced preference for the tastes of starch-derived polysaccharides. Three of these compounds--Polycose, maltotriose and amylopectin--were used along with a standard array of chemicals in a study of their effectiveness as taste stimuli, as monitored by evoked single unit activity in the nucleus tractus solitarii (NTS). Maltotriose and amylopectin elicited very few spikes and no clear quality-related pattern of neural activity. Polycose, however, was an effective taste stimulus. It evoked an activity profile across neurons and over time that was poorly correlated with that of the prototypical sugar (sucrose) and only moderately related to those of the non-sugar prototypes (NaCl, HCl and quinine-HCl). The 14 cells (23%) that responded particularly well to Polycose were all members of neuronal subgroups that emphasized salt, acid and quinine sensitivity. Thus, despite the strong behavioral preference shown to Polycose, its neural profile is unlike those of other preferred stimuli. Polycose may represent a unique taste stimulus whose quality cannot be readily associated with those of the traditional 4 basic tastes.

Immunocytochemical detection of kappa and lambda light chain V region subgroups in human B-cell malignancies.

We have used a sensitive immunoperoxidase method and highly specific anti-light chain antisera to determine the light chain variable region (VL) subgroup nature of cytoplasmic (c) and cell surface (s) Ig expressed by human monoclonal plasma cells and B lymphocytes. The immunocytochemical characterization of cIg and sIg used antisera specific for the established kappa light chain V kappa subgroups (V kappa I, V kappa II, V kappa III, and V kappa IV) and the lambda light chain V lambda subgroups (V lambda I, V lambda II/V, V lambda IV, and V lambda VI). Studies were performed using cytospin preparations of bone marrow-, peripheral blood-, and lymph node-derived cells from patients with multiple myeloma, amyloidosis AL, and Waldenström's macroglobulinemia and with low-, mid-, and high-grade B-cell malignancies. The V kappa or V lambda subgroup of the cIg or sIg also could be identified after deparaffinization and enzyme treatment of formalin-fixed, paraffin-embedded specimens. For those patients who had monoclonal serum or urinary Igs, there was complete concordance between the VL subgroup of the secreted Ig and that of the cIg or sIg. The percentage distribution of V kappa or V lambda subgroups on the sIg of cells from patients with chronic lymphocytic leukemia (CLL) and other cytomorphologic types of B-cell malignancies differed from that found for kappa- or lambda-type Bence Jones proteins obtained from patients with multiple myeloma, amyloidosis AL, and Waldenström's macroglobulinemia. In contrast to the plasma cell and lymphocytoid plasma cell diseases, a relative predominance of certain VL subgroups, ie, V kappa IV, V lambda III, and V lambda IV, and the absence of the amyloid-associated V lambda VI subgroup were found in CLL and related diseases. The immunocytochemical techniques used make possible a rapid means to demonstrate B-cell monoclonality and provide further evidence for the selective expression of certain VL genes in human B-cell neoplasia.