Connective tissue metabolism in children with chronic renal failure

To assess the characteristics of connective tissue metabolism in chronic renal failure (CRF), urinary excretion of glycosaminoglycan (GAG) fractions and hydroxyproline (HYP) was determined in ten patients with CRF and in ten age-matched healthy children. CRF was found to be associated with elevated free HYP (19.9±6.1 vs 9.8±3.6 mol/day,P<0.05) and depressed peptide HYP excretion (33.1±13.5 vs 225.2±17.7 mol/day,P<0.01), a low rate of total GAG excretion (7.0±2.4 vs 16.1±1.9 mol uronic acid/day,P<0.05) with low chondroitin 4 — sulphate + chondroitin 6 — sulphate (Ch-Ss) (14.0±9.9 vs 65.0±22.1%) and a high proportion of non-sulphated or under-sulphated fractions, i.e. hyaluronic acid + chondroitin + heparan sulphate (HA+Ch+HS) (75.3±11.4 vs 31.5±5.7%). Urinary 3-methyl-histidine (3-met-HIS) excretion and plasma essential free amino acids did not differ in the two groups. In response to haemodialysis no consistent change occurred in urinary excretion of 3-met-HIS, peptide-bound HYP, total GAG or percentage distribution of individual GAG fractions. After haemodialysis all plasma amino acids decreased significantly, and there was a significant increase in urinary excretion of free HYP (P<0.05). We conclude that the alterations in urinary excretion of total and individual GAGs observed in CRF may reflect disturbed connective tissue metabolism which does not appear to be accounted for by protein malnutrition or enhanced protein breakdown and remains uninfluenced by haemodialysis therapy.     

In vivo and in vitro models demonstrate a role for caveolin-1 in the pathogenesis of ischaemic acute renal failure

Caveolae and their proteins, the caveolins, transport macromolecules; compartmentalize signalling molecules; and are involved in various repair processes. There is little information regarding their role in the pathogenesis of significant renal syndromes such as acute renal failure (ARF). In this study, an in vivo rat model of 30 min bilateral renal ischaemia followed by reperfusion times from 4 h to 1 week was used to map the temporal and spatial association between caveolin-1 and tubular epithelial damage (desquamation, apoptosis, necrosis). An in vitro model of ischaemic ARF was also studied, where cultured renal tubular epithelial cells or arterial endothelial cells were subjected to injury initiators modelled on ischaemia-reperfusion (hypoxia, serum deprivation, free radical damage or hypoxia-hyperoxia). Expression of caveolin proteins was investigated using immunohistochemistry, immunoelectron microscopy, and immunoblots of whole cell, membrane or cytosol protein extracts. In vivo, healthy kidney had abundant caveolin-1 in vascular endothelial cells and also some expression in membrane surfaces of distal tubular epithelium. In the kidneys of ARF animals, punctate cytoplasmic localization of caveolin-1 was identified, with high intensity expression in injured proximal tubules that were losing basement membrane adhesion or were apoptotic, 24 h to 4 days after ischaemia-reperfusion. Western immunoblots indicated a marked increase in caveolin-1 expression in the cortex where some proximal tubular injury was located. In vitro, the main treatment-induced change in both cell types was translocation of caveolin-1 from the original plasma membrane site into membrane-associated sites in the cytoplasm. Overall, expression levels did not alter for whole cell extracts and the protein remained membrane-bound, as indicated by cell fractionation analyses. Caveolin-1 was also found to localize intensely within apoptotic cells. The results are indicative of a role for caveolin-1 in ARF-induced renal injury. Whether it functions for cell repair or death remains to be elucidated.     

Urinary endothelin excretion in the neonate: influence of maturity and perinatal pathology

The present study was undertaken to establish the developmental pattern of urinary endothelin-1 (ET-1) excretion and to define its possible role in mediating pathophysiological changes related to perinatal asphyxia/infection and dopamine treatment. Urinary ET-1 levels were measured by radioimmunoassay in 7 full-term neonates (mean gestational age 39.3 weeks) on days 1, 3 and 5, and in 9 pre-term neonates (mean gestational age 30.8 weeks) on days 1, 3, 5, 7 and weekly thereafter for 5 consecutive, weeks. The results were compared with those of three age-groups of 30 normal children (4–8 years, 9–12 years and 13–18 years); each group, consisted of 10 children. The influence of severe cardiopulmonary distress (n=16, mean gestational age 33.9 weeks, post-natal age 3.3 days) and dopamine administration in a dose of 2 g/min per kg (n=10, mean gestational and post-natal ages 32.1 weeks and 5.6 days, respectively) were also studied. In full-term infants, ET-1 concentration fell from 34.3±1.8 pmol/l on day 1 to 21.5±1.5 pmol/l on day 5 (P<0.01). In premature infants its absolute value and its post-natal fall were similar in the 1st week and no further change occurred in weeks 2–5; it stabilized at levels between 17.1±2.2 and 16.7±1.7 pmol/l. These concentrations tended to be lower than those of 25.5±1.3, 23.0±1.0 and 26.2±0.7 pmol/l measured in three groups of older children. During the 1st week, daily ET-1 excretion remained unchanged in term infants (3.1±1.0 vs. 3.7±1.5 pmol/m² per day), but there was a significant increase from 6.5±1.0 to 12.4±0.7 pmol/m² per day (P<0.01) in premature infants. During weeks 2–5, preterm infants excreted more ET-1 than older children (P<0.01). In response to perinatal ashphyxia/infection and dopamine therapy, urinary ET-1 excretion markedly rose and there was a significant positive correlation between urine flow rate and ET-1 excretion (P<0.001). We conclude that ET-1 concentration rather than excretion rate may have a role in mediating the changes in renal functions that occur soon after birth. The pathophysiological significance of the flow-dependent increase in urinary ET-1 excretion needs to be further studied.     

Cellular and molecular bases of allergic diseases of the conjunctiva

The authors review the clinical signs of the five most frequent allergic diseases of the conjunctiva (seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal conjunctivitis, atopic conjunctivitis and giant papillary conjunctivitis), and then the immunologic bases of the development of the early-type allergic reaction. In the course of this, they describe the roles played by IgE globulin and the mastocytes in histamine release, and also the possible effects manifested in allergic inflammation in consequence of the metabolic products of arachidonic acid formed in the cell membrane (leukotrienes, lipoxins, prostaglandins and thromboxanes). Following this, they present an account of the process by which the eosinophilic cells that play the main role in the later stages of allergic inflammation emerge from te vascular bed, and the effects of various adhesion molecules. Finally, they discuss a new classification of conjunctivitis (proposed by Bonini), based on the pathomechanisms of the diseases.     

Hyperuricemia predicts adverse clinical outcomes after cardiac resynchronization therapy

Abstract

Objectives: Changes in the levels of serum creatinine and N-terminal of prohormone brain natriuretic peptide (NT-proBNP) are useful risk markers after cardiac resynchronization therapy (CRT). The diagnostic value of changes in serum uric acid levels has been established in chronic heart failure, but no data are available on the prognostic value of hyperuricemia in a CRT population. Design: We measured markers of renal function [creatinine, blood urea nitrogen (BUN) and uric acid] and NT-proBNP levels of 129 heart failure patients undergoing CRT in a prospective, observational study. The 5-year all-cause mortality and the 6-month clinical response (≥ 15% increase in the left ventricular ejection fraction) were considered as study end points. Results: In multivariable analyses, the uric acid was found to be a statistically significant predictor of the outcome. Uric acid levels exceeding 386?mmol/L before CRT increased the chances of mortality [n?=?55, hazard ratio?=?2.39 (1.30-4.39), p?<?0.01] and poor clinical response [n?=?37, odds ratio?=?2.89 (1.22-6.87), p?=?0.01] independently of serum NT-proBNP and other factors. Conclusions: Elevated uric acid concentrations in patients with CRT are associated with an increased risk of mortality and poor clinical response independently of the NT-proBNP levels and other relevant clinical factors.     

Pregnant intravenous drug user tricuspid valve infective endocarditis treated with a successful simultaneous valve replacement and Cesarean section

A 30‐year‐old female patient known to be an intravenous drug user (IVDU) was admitted to Bajcsy‐Zsilinszky Hospital Cardiology Intensive Care Unit at 29‐week gestation with severe sepsis and right heart failure. She had methicillin‐sensitive Staphylococcus aureus on blood culture. Echocardiography confirmed the diagnosis of tricuspid valve infective endocarditis (IE). She had acute deterioration and hemodynamic instability for which an emergency tricuspid valve replacement (TVR) with a simultaneous Cesarean section (CS) was performed simultaneously. Medical management is the standard treatment in IE of IVDU pregnant patients, but in case of life‐threatening complications, emergency TVR and CS are to be considered. This is the first reported case of IVDU IE treated with simultaneous TVR and CS.     

Examination of pituitary adenylate cyclase-activating polypeptide in Parkinson’s disease focusing on correlations with motor symptoms

GeroScience - The neuroprotective effects of pituitary adenylate cyclase-activating polypeptide (PACAP) have been shown in numerous in vitro and in vivo models of Parkinson’s disease (PD)...