Serum concentrations of laminin-P1 in thrombotic microangiopathy: usefulness as an index of activity and prognostic value

Laminin is the main noncollagenous constituent of the basement membrane, and its serum levels could reflect the metabolic changes that occur in the basement membrane. Severe endothelial injury with thickening of basement membrane is a characteristic feature of thrombotic microangiopathy (TMA). With this background, the aim of the study was to investigate in a prospective way (1) the relationship among serum Lam-P1, the extent of renal histopathologic lesions, and the biochemical parameters commonly used as markers of TMA activity, and (2) the usefulness of serum Lam-P1 concentrations as a renal outcome prognostic index. To this end, 18 consecutive patients with active biopsy-proven TMA with renal involvement were studied. One hundred and twenty-one healthy control subjects, 20 patients with systemic scleroderma without renal involvement, and 35 patients with systemic lupus erythematosus (20 without nephropathy and 15 with diffuse proliferative type 4 lupus nephritis) were used as control groups. In addition, to analyze the influence of either renal failure or hemodialysis therapy on serum Lam-P1 levels, 91 patients on regular hemodialysis therapy and 81 patients with predialysis chronic renal failure of different etiologies were included in the study. Serum Lam-P1 was determined by RIA at admission, on days 10 and 30 of follow-up in all patients, and after 6 and 12 mo of follow-up in all surviving patients. Serum lactate dehydrogenase, haptoglobin, platelet count, hemoglobin, and serum creatinine were determined as markers of endothelial dysfunction and hemolysis. At admission, serum levels of Lam-P1 were significantly higher in patients with TMA than in healthy control subjects (3.39 +/- 0.56 U/ml versus 1.40 +/- 0.18 U/ml; P < 0.0001). In addition, patients with TMA had significantly higher serum Lam-P1 levels than the other groups included in the study. At the first control, Lam-P1 correlated with lactate dehydrogenase (P = 0.006) and hemoglobin (P = 0.002). During follow-up, platelet count and hemolysis indicators normalized in all patients, while serum Lam-P1 decreased only in patients with renal function recovery. In multivariate analysis, serum creatinine and Lam-P1 at day 10 were the only independent predictors of renal outcome (r2 = 0.94; P < 0.0001) and also correlated with indices of histopathologic damage (P < 0.001). Serum Lam-P1 normalized in all patients with chronic renal failure in the samples obtained at 6 and 12 mo of regular hemodialysis after solving active TMA, thus suggesting that histopathologic lesions, but not renal function itself, would be mainly responsible for the high Lam-P1 serum concentrations detected in TMA. In conclusion, serum Lam-P1 concentrations are increased in patients with active TMA. Furthermore, patients with poor renal outcome show a prolonged increase of serum Lam-P1 that is related to the extent of renal histologic lesions. Unlike the biochemical markers of hemolysis commonly used to assess TMA activity, the sequential determination of serum Lam-P1 provides valuable information about long-term renal prognosis in patients with TMA.     

Decrease in pathology and progression of scrapie after immunisation with synthetic prion protein peptides in hamsters

Effective therapy for prion diseases is currently unavailable. Recently, vaccination was shown to be effective in mouse models of a particular neurodegenerative conditions: Alzheimer's disease (AD). Here, we report that vaccination with synthetic oligopeptides homologous to the hamster (Mesocricetus auratus) prion protein augments survival time in animals infected intraperitoneally with 263K scrapie agent. For each hamster included in the study, prion-specific serum antibodies as well as deposition of pathological prion protein (PrP(res)), glial fibrillary acidic protein (GFAP), and mRNA expression for cytokines (TNF alpha, IL-1beta, IL-10) in brain tissues were evaluated. In immunized animals, increased survival after challenge was associated with a reduction of cerebral lesion, PrP deposition and GFAP expression; in these animals, anti-prion protein peptide antibody levels were increased, and the expression of pro-inflammatory cytokines (TNF alpha and IL-1beta) was reduced. Vaccination could be an effective therapeutic approach to postpone disease onset.     

Effect of ghrelin on the apoptotic deletion rate of different types of cells cultured in vitro

Evidence indicates that ghrelin, an endogenous ligand of the growth hormone secretagogue receptor, controls the growth of several human and rat cell types cultured in vitro. Hence, we have investigated, by using both TUNEL and ELISA assays, the effects of 10(-8) M ghrelin on the basal apoptotic deletion rate of rat osteoblasts and thymocytes, rat and human adrenocortical cells, human umbilical vein endothelial cells, and human aldosteronoma cells cultured in vitro, as well as of the human adrenocortical carcinoma-derived cell lines NCI-H295 and SW-13. Both assays consistently showed that ghrelin did not affect apoptotic rate of normal rat and human cells, but significantly enhanced apoptotic deletion in aldosteronoma, NCI-H295 and SW-13 cell cultures. Due to the central role of apoptosis in the control of tumor growth, these findings, if confirmed in other tumor cell types, could suggest an antitumoral action of ghrelin.     

In vitro culture of rat neuromicrovascular endothelial cells on polymeric scaffolds

Polyphosphazenes are polymers possessing a skeleton composed of alternating phosphorous and nitrogen atoms, and two side-moieties linked to each phosphorous atom. Polyphosphazenes with amino acid esters as side-moieties are biocompatible and biodegradable polymers. Two polyphosphazenes, poly[bis(ethyl alanate) phosphazene] and poly[(ethyl phenylalanate)0.8(ethyl alanate)0.8(ethyl glycinate)0.4 phosphazene] (PPAGP) were synthesized, and processed to form small fibers. Their ability to support rat neuromicrovascular endothelial cell (EC) adhesion and growth has been studied, using poly(D,L-lactic acid) as reference compound. Scanning electron microscopy revealed that both poly[bis(ethyl alanate) phosphazene] and PPAGP fibers were thinner than poly(D,L-lactic acid) fibers, and possessed a more irregular and porous surface. All polymers increased EC adhesion, compared with polystyrene, but only polyphosphazenes were able to improve EC growth. The highest increase in EC proliferation was induced by PPAGP, which, as revealed by environmental scanning electron microscopy, was also able to induce ECs to arrange into tubular structures. The conclusion is drawn that PPAGP may provide the best scaffold for engineered blood vessels, because it promotes adhesion, growth, and organization of ECs into capillary-like structures.     

Comparison between rules-based human immunodeficiency virus type 1 genotype interpretations and real or virtual phenotype: concordance analysis and correlation with clinical outcome in heavily treated patients

We compared 2 rules-based genotype interpretation systems and real or virtual phenotype through a retrospective analysis of a prospective trial. Genotypes were determined with VircoGEN II (VIRCO) and were interpreted with either RetroGram 1.4 or TRUGENE HIV-1 (guidelines 3.0) or original virtual phenotype (Virtual Phenotype; VIRCO), as available in the year 2000. Among 188 human immunodeficiency virus (HIV) type 1 isolates, overall concordance (kappa agreement) was observed for the 2 rules-based systems, whereas striking discordances were noted between them and real and virtual phenotype interpretations for stavudine, didanosine, zalcitabine, abacavir, and amprenavir (kappa<0.4). Clinical evaluation of a subset of 173 patients showed that both rules-based sensitivity scores were independently associated with HIV RNA loads <400 copies/mL at week 16 of during-treatment analysis (TRUGENE: odds ratio [OR], 2.90; 95% confidence interval [CI], 1.52-5.52; P=.001; RetroGram: OR, 2.34; 95% CI, 1.21-4.55; P=.012), whereas, in contrast to real or virtual phenotype, interpretations according to biological cut-offs were not (OR, 1.91; 95% CI, 0.77-4.76; P=.162).     

Iron supplementation in a child with severe burns

Non-intentional burns are still a frequent cause of morbidity in children despite the implementation of preventive campaigns. Children with severe burns (more than 10 % of the body surface) may require iron supplementation, especially in the post-stress or recovery phase. We report the case of a 15-month-old boy, who suffered polytrauma and burns to 20 % of the body surface. A dermal graft was performed eight days after his admission to the pediatric burns unit, which required transfusion of packed red blood cells. On day 15 hemoglobin value was 9.3 g/dL, the reticulocyte hemoglobin content was reduced to 26.2 pg (normal value: 27.2-30.3 pg) and the reticulocyte mean corpuscular value was increased to 124 fl (normal value: 101-108 fl). These findings were interpreted as a functional iron insufficiency, despite the increased ferritin value (219 ng/mL). We highlight the satisfactory outcome of the different hematologic values, with the development of reticulocyte crisis and normalization of hematological parameters after administration of 0.5 mg/kg/day of ferrous sulfate, plus iron corresponding to the follow-up milk formula and a regular diet for the child's age.     

Physiological effects of translaryngeal open ventilation in patients with restrictive respiratory disorders

OBJECTIVE: To compare the efficacy of pressure-controlled ventilation (PCV) delivered through a conventional endotracheal tube with the same ventilatory mode using a small-size tube with the cuff left deflated (translaryngeal open ventilation: TLOV). SETTING: A medical-surgical intensive care unit (ICU). DESIGN: Prospective physiological study. PATIENTS: Thirteen consecutive patients with restrictive neuromuscular and thoracic respiratory disorders ventilated in pressure-controlled mode. INTERVENTIONS: The standard tube was removed and a microlaryngeal tube (i.d. 4 mm, o.d. 6 mm, length 380 mm) was inserted with the cuff left deflated. PCV was increased to match the tracheal pressure measured during conventional ventilation. Arterial blood gases were measured before, 1 h and 20 h after initiating TLOV. A patient comfort score was measured by a visual analogue scale during conventional ventilation and 20 h after initiating TLOV (0= very bad, 1= bad, 2= quite bad, 3= sufficient, 4= good, and 5= very good). RESULTS: Inspiratory pressure was significantly increased from 16+/-5 cmH(2)O to 68+/-13 cmH(2)O after 1 h and to 65+/-12 cmH(2)O after 20 h to match the tracheal pressure measured during conventional ventilation (CV) (p<0.005). No statistically significant differences were found in arterial blood gases and patient's respiratory rate before and after 1 and 20 h of TLOV. The comfort score was 1.3+/-0.4 and 3.6+/-0.4 during CV and TLOV, respectively, on a scale from 0 to 5 (p<0.002). CONCLUSION: This study indicates that, in selected patients, TLOV was as efficient as conventional PCV.     

RETMEN2A and RETMEN2B oncoproteins are targets of PP1 inhibitor

Medullary thyroid carcinoma (MTC) responds very poorly to chemotherapy. Mutations in the RET gene are critical for MTC pathogenesis. RET therefore represents a rational target for the development of novel MTC therapies. The accumulation of evidence from laboratory studies strongly suggests that PP1 inhibitor is a cytostatic agent for cells expressing RET oncoproteins. PP1 functions as a potent and selective inhibitor of RET oncoprotein phosphorylation, promoting its proteasomal degradation.     

Circulating levels of plasminogen activator inhibitor type-1, tissue plasminogen activator, and thrombomodulin in hemodialysis patients: biochemical correlations and role as independent predictors of coronary artery stenosis

This study investigated the relationship between the circulating levels of the endothelial cell glycoproteins plasminogen activator inhibitor type 1 (PAI-1), tissue plasminogen activator (TPA), and thrombomodulin (TM) and the major vascular risk factors described in dialysis patients. In addition, the role of these endothelial cell products as independent predictors of coronary artery disease (CAD) was analyzed. Levels of TM, TPA antigen (Ag), TPA activity, PAI-1 Ag, PAI-1 activity, TPA/PAI complexes, thrombin-antithrombin complexes, fibrinopeptide A, C-reactive protein (CRP), interleukin-1beta and tumor necrosis factor-alpha, lipids, apoproteins A1 and B, and albumin were measured in a group of 200 nondiabetic dialysis patients and 100 healthy matched volunteers. When compared with healthy controls, dialysis patients showed increased levels of CRP, TM, TPA, and PAI-1 and evidence of increased thrombin-dependent fibrin formation. Increased levels of active PAI-1 were associated to a great extent with major classic vascular risk factors and to a lesser extent with CRP and serum triglycerides. Forty-six patients (23%) had evidence of CAD. Variables associated with CAD in the univariate analysis included age, time on dialysis, male gender, number of packs of cigarettes per year, high BP, fibrinogen, apolipoprotein B, albumin, PAI-1 activity, CRP, thrombin-antithrombin complexes, and fibrinopeptide A. Logistic regression analysis found age, high-density lipoprotein cholesterol, gender, high BP, CRP, time on dialysis, and PAI-1 activity to be independent predictors of CAD. This model classified correctly 85% of patients as having CAD and showed adequate goodness of fit for all risk categories. Our data support a pathogenic link among activated inflammatory response, endothelial injury, and CAD in hemodialysis patients and suggest that assessment of circulating PAI-1 levels could be an additional tool to identify dialysis patients who are at risk for developing atheromatous cardiovascular disease.