Non-functional alternative splicing caused by a Latino pathogenic variant in a case of PMM2-CDG.

We report on a Mexican mestizo with a multisystemic syndrome including neurological involvement and a type I serum transferrin isoelectric focusing (Tf IEF) pattern. Diagnosis of PMM2-CDG was obtained by clinical exome sequencing (CES) that revealed compound heterozygous variants in PMM2, the encoding gene for the phosphomannomutase 2 (PMM2). This enzyme catalyzes the conversion of mannose-6-P to mannose-1-P required for the synthesis of GDP-Man and Dol-P-Man, donor substrates for glycosylation reactions. The identified variants were c.422G>A (R141H) and c.178G>T, the former being the most frequent PMM2 pathogenic mutation and the latter a previously uncharacterized variant restricted to the Latino population with conflicting interpretations of pathogenicity and that we here report causes leaky non-functional alternative splicing (p.V60Cfs*3).

Coadministration of the Campylobacter jejuni N-Glycan-Based Vaccine with Probiotics Improves Vaccine Performance in Broiler Chickens.

Source attribution studies report that the consumption of contaminated poultry is the primary source for acquiring human campylobacteriosis. Oral administration of an engineered Escherichia coli strain expressing the Campylobacter jejuni N-glycan reduces bacterial colonization in specific-pathogen-free leghorn chickens, but only a fraction of birds respond to vaccination. Optimization of the vaccine for commercial broiler chickens has great potential to prevent the entry of the pathogen into the food chain. Here, we tested the same vaccination approach in broiler chickens and observed similar efficacies in pathogen load reduction, stimulation of the host IgY response, the lack of C. jejuni resistance development, uniformity in microbial gut composition, and the bimodal response to treatment. Gut microbiota analysis of leghorn and broiler vaccine responders identified one member of Clostridiales cluster XIVa, Anaerosporobacter mobilis, that was significantly more abundant in responder birds. In broiler chickens, coadministration of the live vaccine with A. mobilis or Lactobacillus reuteri, a commonly used probiotic, resulted in increased vaccine efficacy, antibody responses, and weight gain. To investigate whether the responder-nonresponder effect was due to the selection of a C. jejuni "supercolonizer mutant" with altered phase-variable genes, we analyzed all poly(G)-containing loci of the input strain compared to nonresponder colony isolates and found no evidence of phase state selection. However, untargeted nuclear magnetic resonance (NMR)-based metabolomics identified a potential biomarker negatively correlated with C. jejuni colonization levels that is possibly linked to increased microbial diversity in this subgroup. The comprehensive methods used to examine the bimodality of the vaccine response provide several opportunities to improve the C. jejuni vaccine and the efficacy of any vaccination strategy.IMPORTANCECampylobacter jejuni is a common cause of human diarrheal disease worldwide and is listed by the World Health Organization as a high-priority pathogen. C. jejuni infection typically occurs through the ingestion of contaminated chicken meat, so many efforts are targeted at reducing C. jejuni levels at the source. We previously developed a vaccine that reduces C. jejuni levels in egg-laying chickens. In this study, we improved vaccine performance in meat birds by supplementing the vaccine with probiotics. In addition, we demonstrated that C. jejuni colonization levels in chickens are negatively correlated with the abundance of clostridia, another group of common gut microbes. We describe new methods for vaccine optimization that will assist in improving the C. jejuni vaccine and other vaccines under development.

Supramolecular structure, phase behavior and thermo-rheological properties of a poly (L-lactide-co-ε-caprolactone) statistical copolymer.

PLAcoCL samples, both unaged, termed PLAcoCLu, and aged over time, PLAcoCLa, were prepared and analyzed to study the phase structure, morphology, and their evolution under non-quiescent conditions. X- ray diffraction, Differential Scanning Calorimetry and Atomic Force Microscopy were complemented with thermo-rheological measurements to reveal that PLAcoCL evolves over time from a single amorphous metastable state to a 3 phase system, made up of two compositionally different amorphous phases and a crystalline phase. The supramolecular arrangements developed during aging lead to a rheological complex behavior in the PLAcoCLa copolymer: Around Tt=131 °C thermo-rheological complexity and a peculiar chain mobility reduction were observed, but at T>Tt the thermo-rheological response of a homogeneous system was recorded. In comparison with the latter, the PLLA/PCL 70:30 physical blend counterpart showed double amorphous phase behavior at all temperatures, supporting the hypothesis that phase separation in the PLAcoCLa copolymer is caused by the crystallization of polylactide segment blocks during aging.

Analysis of expression and function of the co-stimulatory receptor SLAMF1 in immune cells from patients with systemic lupus erythematosus (SLE).

The signaling lymphocytic activation molecule SLAMF1 (CD150) is a co-stimulatory molecule that is expressed by most immune cells, including T regulatory (Treg) lymphocytes. Since different abnormalities have been reported regarding the number and function of Foxp3+ Treg cells in patients with systemic lupus erythematosus (SLE), we decided to analyze the expression and function of CD150 in these regulatory lymphocytes in this condition. We isolated peripheral blood mononuclear cells from 20 patients with SLE, and 20 healthy controls. The expression of SLAMF1 was determined by multi-parametric flow cytometry and the suppressive function of CD4+CD25+ lymphocytes, upon engagement or not of CD150 with an agonistic monoclonal antibody, was analyzed by an assay of inhibition of cell proliferation. We observed a significantly increased expression of SLAMF1 by CD3+CD4+ helper T cells and CD19+ B cells in patients with SLE and active disease. However, similar levels of SLAMF1 expression were detected in Foxp3+ Treg cells from patients and controls. In contrast, a higher proportion of SLE patients increased their suppressive function of Treg cells upon CD150 engagement compared to healthy controls. Our data suggest that SLAMF1 is another significant piece in the intricate defective immune-regulatory function of patients with SLE.

Histoplasmose pulmonar canina no estado de Pernambuco, Brasil: relato de caso / Canine pulmonary histoplasmosis in Pernambuco State, Brazil: case report

A histoplasmose é uma das principais doenças micóticas que acometem o trato respiratório inferior de pequenos animais, sendo ocasionada pelo Histoplasma capsulatum, fungo encontrado em solos ricos em compostos nitrogenados, derivados de matéria orgânica em decomposição. Descreve-se um caso de histoplasmose pulmonar em um canino da raça Boxer, domiciliado no estado de Pernambuco, Brasil, o qual apresentava uma síndrome respiratória com evolução clínica de aproximadamente seis meses. Na análise citopatológica do lavado broncoalveolar, foram visualizadas estruturas leveduriformes de aproximadamente dois micrômetros de diâmetro, características de H. capsulatum, sendo, então, indicada a terapia com itraconazol. O exame citopatológico do lavado broncoalveolar é uma ferramenta diagnóstica importante na identificação do agente, e o tratamento com itraconazol é eficiente, levando à remissão completa dos sinais clínicos.

Histoplasmosis is a main fungal diseases that affect the lower respiratory tract of small animals, being caused by Histoplasma capsulatum, a fungus found in soil rich in nitrogen compounds, derived from decaying organic matter. It is described a case of pulmonary histoplasmosis in a dog of Boxer breed, domiciled in the state of Pernambuco, Brazil, which had a respiratory syndrome with clinical course of about six months. On cytopathological examination of bronchoalveolar lavage were visualized yeast structures of approximately two micrometers in diameter, characteristics of H. capsulatum, and then was indicated therapy with itraconazole. The cytopathological examination of bronchoalveolar lavage is an important diagnostic tool in the identification of the agent and the treatment with itraconazole is efficient, leading to complete remission of clinical signs.

Spawning failure in Brycon amazonicus may be associated with ovulation and not with final oocyte maturation / A falha na desova de fêmeas de Brycon amazonicus pode estar relacionada com ovulação e não com a indução a maturação final dos ovócitos

Avaliaram-se os possíveis mecanismos envolvidos com a falha na desova de matrinxãs (Brycon amazonicus), submetidas à indução hormonal por extrato bruto de hipófise de carpa. Para tal, após a extrusão, os ovários foram coletados e analisados histomorfometricamente. Nas fêmeas que não desovaram (FNDs), a maioria dos ovócitos vitelogênicos remanescentes nos ovários atingiu a maturação final, apresentando quebra de vesícula germinativa, mas não foram ovulados (NOs). Consequentemente, estas fêmeas apresentaram frequências mais baixas de folículos pós ovulatórios (5%) quando comparadas com a que desovou (FD) (23%). Com relação aos NOs, os valores se inverteram e a frequência destes nas FNDs (21%) foi maior do que na FD (3%). Estes dados indicam que as falhas na desova desta espécie estão provavelmente relacionadas com a ovulação, uma vez que a maturação final dos ovócitos ocorre de forma similar tanto nas FNDs como na FD. Os dados sugerem que as substâncias que promovem a ovulação, como as prostaglandinas, podem aumentar o sucesso de desova em peixes reofílicos.

[Early diagnosis of hip dysplasia. Crippling disease for life. Consensus of the Mexican College of Orthopedics and Traumatology]. / El diagnóstico oportuno de la displasia de cadera. Enfermedad discapacitante de por vida. Consenso del Colegio Mexicano de Ortopedia y Traumatología.

The developmental dysplasia of the hip (DDH), where the spectrum of deformity varies from a slight mismatch in the articular surfaces between the ilium and femur, which will bring a premature wear of the joint, until the situation more serious when the femoral head is out of the acetabulum, causing a host of disorders side as curvature of the spine, significant shortening of the limb deformities in the knee and the contralateral hip, as well as causing pain and loss of joint mobility mentioned. All this makes the spectrum of abnormalities in a person being disabled with a social and economic burden for the family and society. "Preventing" a clinical entity such as developmental dysplasia of the hip does not mean to anticipate the presentation, because children continue to be born with this problem, but to have a program for early detection and early treatment and thus prevent the occurrence. The goal of this study was to provide the medical community that timely tool for prevention. When diagnosed and treated in a timely and favorable prognosis qualified for motor function and quality of life.

[Utility of the ECMO in patients with congenital diaphragmatic hernia]. / Utilidad de la ECMO en pacientes con hernia diafragmática congénita.

At the moment the extracorporeal membrane oxygenation (ECMO) constitutes the last link in the therapeutic one of the handling of the respiratory failure in patients with Congenital Diaphragmatic Hernia (HDC). We presented our experience. From January 2001 we arrange the ECMO in neonative UCI. 76 HDC, 13 (3 rights and 10 lefts) they have needed ECMO (one in two occasions; altogether 14 procedures). Criteria of inclusion: refractory hypoxaemia, oxigenaction index > 40 and weight > 2 kg. 5 girls and 8 boys with gestacional age between 35 and 41 weeks (average: 38) and weight when being born between 2,300 and 3,500 grams (average 2,817). In 6 cases (5 transferred from other centers) the diagnosis was posnatal. Of the 7 with prenatal diagnosis, in 4 cases fetal therapy by means of traqueal occlusion had been made. Veno-venous in 8 and veno-arterial procedure in 5. Rank of duration: 68-606 hours, average of 228.35. The surgery has been made before the ECMO in 9 cases, 2 during and 1 later. In an occasion there was no surgery. The complications have been of hemorrágico type in one patient and infectious in three cases with sudden sepsis in one. Precocious mortality has been of 6 patients and delayed the 2 (total 61%). Although this procedure has the high morbi-mortality, it is necessary to consider that is patients very badly prognosis without another alternative (with mortality of the 100%). Multicentric studies are needed to establish indicators prognoses pre and postbirthdays.

[Our experience in the treatment of proximal hypospadias in a single surgical intervention]. / Nuestra experiencia en el tratamiento del hipospadias proximal en un solo tiempo quirúrgico.

BACKGROUND: The surgical correction of proximal severe hypospadias, especially those with penoscrotal transposition (penis buried in scrotum), represents a true challenge for paediatric surgeons. A sequential approach to their repair is widely accepted, to preserve the vascularization of the neourethra and to avoid injuries in penis covering. In our experience, we believe that all hypospadias, even those associated with penoscrotal transposition, can be repaired in one surgical time by using a vascularized flap from dorsal prepuce in one or two layers (mucosal portion for urethra and skin face for ventral island). MATERIALS AND METHODS: From 1997 until 2007, 88 patients with proximal severe hypospadias have been operated. 35 patients associated penoscrotal transposition. Since 2005, we introduced a modification consisting in drawing the incisions following the own cutaneous folds resulting from the fusion of the lateral folds in penis skin. RESULTS: We performed Duckett type urethroplasty in 10 patients, Onlay type flap in 74, Onlay with oral mucosa in 2 and vesical mucosa urethroplasty in 2 of them. The fistula rate needing surgical closure was 17% (15/88), urethral stenosis was present in 5 patients (5.7%, 1 vesical mucosa, 2 Duckett urethrolpasties and 2 Onlay flaps). Severe complications were represented by partial necrosis of the skin flap in 3 patients (3.4%) needing a reurethroplasty. 1 patient presented surgical wound infection without later problems. Before 2005, among the 22 patients with penoscrotal transposition, 5 needed a new cutaneoplasty, associated in 2 occasions to a dorsal Nesbitt plicature to obtain the complete penis alignment. From 2005 until now, None of the 13 patients presenting with penoscrotal transposition needed any posterior cutaneoplasty. The follow up goes from 1 month until 10 years (median 45 months). At present time, urine spurt shows a correct range in all cases and the penis is located out of scrotal bag except in one patient, waiting for a new plasty. DISCUSSION: In our experience, we believe that all of the hypospadias may be repaired in a unique surgical time, including those of them associated with buried penis. Modification on skin incisions design following penoscrotal lateral folds with mucocutaneous preputial flap is an excellent option both for urethroplasty and correcting penis transposition.

A small and active ring X chromosome in a female with features of Kabuki syndrome.

A ring X chromosome is found in about 6% of patients with Turner syndrome (TS), often with mosaicism for a 45,X cell line. Patients with this karyotype are reported to have a higher incidence of a more severe phenotype including mental retardation. In fact, some studies have shown a correlation between this severity and the presence or absence of an intact and functional X inactivation center (XIST). However, the phenotype of the individuals with r(X) cannot be entirely defined in terms of their X-inactivation patterns. Nevertheless, a small group of these patients have been described to manifest clinical features reminiscent of the Kabuki syndrome. Here we present a female patient with clinical features resembling Kabuki syndrome and a mos 45,X/46,X,r(X) karyotype. Methylation analyses of polymorphic alleles of the androgen receptor gene showed that both alleles were unmethylated suggesting an active ring chromosome. A specific X chromosome array CGH was performed estimating the size of the ring to be 17 Mb, lacking the XIST gene, and including some genes with possible implications in the phenotype of the patient.

[Lessons we've learned in the treatment of long gap esophageal atresias]. / Lecciones aprendidas en el tratamiento de las atresias de esófago con gran separación entre sus cabos.

BACKGROUND: A gap greater than 3 cm between both esophageal pouches is observed in 1 of 20 cases of esophageal atresia. Our goal was to critically review our experience in the management of these patients. MATERIAL AND METHODS: During 1995-2004, 15 patients were treated for a long gap esophageal atresia (LEA). Gaps ranged from 3 to 8 cm. Ten patients presented a pure esophageal atresia. They were managed with a gastrostomy and delayed repair: 8 Schärli interventions and 2 esophageal flaps. The other 5 patients had an esophageal atresia with distal fistula (LEA-DF), and primary repair was attempted: 3 end-to-end esophageal anastomosis were achieved under a strong tension; 1 a Schärli procedure; 1 ligation of the fistula, feeding gastrostomy and delayed esophageal flap. The use of esophageal flaps is a late event in our series. since its introduction we've performed 5 esophageal atresia repairs using 3 flaps (2 pure atresias and 1 LEA-DF). RESULTS: From 9 Schärli we have to practice 2 reinterventions for anastomotic leak; there was 1 parahiatal hernia that needed surgery after 8 years. From 3 flaps 2 patients presented a persistent stricture that needed reintervention. All of the 3 E-E anastomosis had reintervention for persistent stricture and also anti-reflux procedures (Nissen). Eight patients showed a normal growth and development (4/9 Schärli, 3/3 flaps and 1/3 E-E). Seven patients are growth retarded (4/7 with associated malformations, 1/7 who developed an eosinophilic esophagitis and 2/7 preterm babies). CONCLUSIONS: The esophageal flap is our first choice, because the own esophagic tissue fills in the gap. In LEA-DF, we prefer fistula ligation, gastrostomy and delayed rise of a flap (as we did in our last patient) better than a very tense primary anastomosis. As a second option, a Schärli procedure offers satisfying mid-term results. Keeping the patient paralyzed and mechanically ventilated for 5-7 days after surgery helps to avoid disrupting forces on the anastomosis.

[Palatal necrosis in children. Case report]. / Necrosis palatina en el lactante. A propósito de un caso.

Palate necrosis as a consequence of palate infection it's an exceptional condition about there's not too much references at literature. We present a case of a 6 months old child who present a palatal necrosis after a supurative medial otitis that involved hard and soft palate, with positive culture for Pseudomona aeruginosa causing a almost complete absence of the palate that simulate a bilateral palatal cleft.

S-adenosylmethionine protects against intrabiliary glutathione degradation induced by long-term administration of cyclosporin A in the rat.

We investigate the ability of S-adenosylmethionine (SAMe) to antagonize the cyclosporine A (CyA)-induced inhibition of biliary glutathione efflux induced by long-term administration of CyA (10 mg/kg per day-CyA10 or 20 mg/kg per day-CyA20 for 4 weeks) in rats. CyA treatment reduced the liver content of total glutathione and caused a significant increase in the oxidized-to-reduced glutathione ratio and the thiobarbituric acid-reactive substances (TBARS) concentration. When the rats were concurrently treated with SAMe (10 mg/kg twice daily) and CyA, all these parameters did not significantly differ from control values. Treatment with CyA induced a significant increase in liver GGT activity that was attenuated by coadministration of SAMe. Biliary efflux of total glutathione was significantly reduced in animals treated with CyA. These changes were abolished by SAMe administration. Following inhibition of the intrabiliary catabolism of the tripeptide by acivicin, glutathione efflux rates increased to a lesser extent in animals cotreated with SAMe when compared to those receiving only CyA. The significant decrease in biliary efflux of oxidized glutathione induced by CyA was totally (S + CyA10) or partially (S + CyA20) prevented by coadministration of SAMe. Our observations confirm that SAMe cotreatment in rats antagonizes CyA-induced inhibition in the biliary efflux of glutathione and suggest that protection against intrabiliary glutathione degradation plays a major role in this protective effect.

Effects of S-adenosylmethionine on intrabiliary glutathione degradation induced by long-term administration of cyclosporin A in the rat.

We investigate the ability of S-adenosylmethionine (SAMe) to antagonize the cyclosporine A (CyA)-induced inhibition of biliary glutathione efflux induced by long-term administration of CyA (10 mg/kg per day-CyA(10) or 20 mg/kg per day-CyA(20) for 4 weeks) in rats. CyA treatment reduced the liver content of total glutathione and caused a significant increase in the oxidized-to-reduced glutathione ratio and the thiobarbituric acid-reactive substances (TBARS) concentration. When the rats were concurrently treated with SAMe (10 mg/kg twice daily) and CyA, all these parameters did not significantly differ from control values. Treatment with CyA induced a significant increase in liver GGT activity that was attenuated by coadministration of SAMe. Biliary efflux of total glutathione was significantly reduced in animals treated with CyA. These changes were abolished by SAMe administration. Following inhibition of the intrabiliary catabolism of the tripeptide by acivicin, glutathione efflux rates increased to a lesser extent in animals cotreated with SAMe when compared to those receiving only CyA. The significant decrease in biliary efflux of oxidized glutathione induced by CyA was totally (S + CyA(10)) or partially (S + CyA(20)) prevented by coadministration of SAMe. Our observations confirm that SAMe cotreatment in rats antagonizes CyA-induced inhibition in the biliary efflux of glutathione and suggest that protection against intrabiliary glutathione degradation plays a major role in this protective effect.

[Predictive value of prenatal MRI in the diagnosis of thoracic congenital malformations]. / Valor predictivo de la RM prenatal en el diagnóstico de las malformaciones congénitas torácicas.

INTRODUCTION: Magnetic imaging (MI) has an increasing value in the prenatal diagnosis of thoracic malformations. MATERIAL AND METHOUS: We compare in this work the prenatal diagnoses with the prenatal sonographic diagnoses and postnatal imaging, surgical or postmortem findings. RESULTS: Prenatal sonography diagnosed 5 diaphragmatic hernias (CDH) and 3 cystic adenomatoid malformations (CAM). MI confirmed left side CDH in 4 cases, in two of them showing also herniation of the left hepatic lobe and the spleen. In the 5th case, MI suggested diaphragmatic eventration with partial occupation of the right hemithorax by the liver. Two of three CAM appeared to have lung sequestration at MI. At birth, four CDH and one diaphragmatic eventration were confirmed by simple x-ray, and by surgery in all but one, a CDH case who went into ECMO and died without surgery. Pulmonary sequestration was postnatally confirmed by CT scan and arteriography. Treatment was coil embolization of the systemic artery. CAM was confirmed postnatally through plain chest film and CT scan. Surgical resection of the lesion was performed and the pathology exam demonstrated the presumed lesion. CONCLUSIONS: When prenatal sonography suggest a fetal thoracic malformation, MI is the way to accurate diagnosis, follow-up, prognostic evaluation and therapeutic strategy.

Effects of aging and cyclosporin treatment on the hepatobiliary efflux of glutathione.

The aim of this study was to investigate the effects of cyclosporin (CyA) treatment on biliary glutathione efflux in rats of different ages (1, 2, 4, and 24 months). CyA treatment reduced the liver content of total glutathione in 1-, 2- and 24 month old rats (-30%, -43% and -30%, respectively). By contrast, oxidized glutathione (GSSG) concentration in liver tended to increase, although non significantly, in the rats aged 4 and 24 month (+36% and +28%, respectively). The oxidized-to-reduced glutathione ratio was significantly increased in 2-, 4- and 24 month old animals (+23%, +36% and >100%, respectively). Regarding biliary glutathione, our data indicate that efflux rates of total glutathione in control (untreated) rats increased to a maximum at 4 months, and decreased (-56%) in 24 month old rats, although values were still higher than those from young animals. CyA treatment significantly reduced biliary glutathione secretion except in 24 month old rats (-98%, -66% and -32%, at 1, 2 and 4 month, respectively). In addition, following inhibition of the intrabiliary catabolism of the tripeptide by acivicin, glutathione efflux rates into bile were significantly reduced by the drug only in 1- and 2 month old rats (-29% and -55%, respectively) and even tended to increase, although non significantly, in oldest animals. Our data indicate that inhibition of biliary glutathione efflux by CyA was greater in younger rats and support the view that increased intrabiliary catabolism of the tripeptide and inhibition of its canalicular transport could contribute to the decline in biliary glutathione secretion induced by the drug.

[Morphologic study of the intestine in an experimental model of amnioinfusion in fetal rabbits with gastroschisis]. / Estudio morfológico del intestino en un modelo experimental de amnioinfusión en feto de conejo con gastrosquisis.

An experimental model of serial amnioinfusion has been developed in fetal rabbits with gastroschisis, using an intraamniotic catheter connected to a subcutaneous port. Fetuses of 4 groups were compared 7 days after surgery: group A: gastroschisis and daily amnioinfusion through an implanted catheter; group C: gastroschisis and blind amniotic catheter; group G: gastroschisis without catheter; group O: nonoperated fetuses. Survival rate, fetal body weight, lung weight, intestinal weight and length were determined. Computer aided morphometric analysis was performed, in which intestinal diameter, thickness and villi length were measured. Amniotic fluid samples were recovered along the experimental period. Intestinal length was significantly shorter and had a significantly thicker wall than nonoperated fetuses; we found no other morphometric differences between gastroschisis treated with amnioinfusion (group A) and the other gastroschisis groups (C and G). Amnioinfusion did not affect fetal survival rate; the amniotic catheter alone did not cause pulmonary hypoplasia due to significant amniotic leak. The physiological decrease in amniotic volume towards the end of gestation has not been modified by this regime of amnioinfusion.

Effects of aging on the susceptibility to the toxic effects of cyclosporin A in rats. Changes in liver glutathione and antioxidant enzymes.

Free radicals are involved in aging and cyclosporin A-induced toxicity. The age-related changes in the liver oxidative status of glutathione, lipid peroxidation, and the activity of the enzymatic antioxidant defense system, as well as the influence of aging on the susceptibility to the hepatotoxic effects of cyclosporin (CyA) were investigated in rats of different ages (1, 2, 4, and 24 months). The hepatic content of reduced glutathione (GSH) increased with aging, peaked at 4 months, and decreased in senescent rats. By contrast, glutathione disulfide (GSSG) and thiobarbituric acid-reactive substances (TBARS) concentrations and superoxide dismutase, catalase, and glutathione peroxidase activities were higher in the oldest than in the youngest rats. CyA treatment, besides inducing the well-known cholestatic syndrome, increased liver GSSG and TBARS contents and the GSSG/GSH molar ratio, and altered the nonenzymatic and enzymatic antioxidant defense systems. The CyA-induced cholestasis and hepatic depletion of GSH, and the increases in the GSSG/GSH ratio, and in GSSG and TBARS concentrations were higher in the older than the mature rats. Moreover, superoxide dismutase and catalase activities were found to be significantly decreased only in treated senescent rats. The higher CyA-induced oxidative stress, lipoperoxidation, and decreases in the antioxidant defense systems in the aged animals render them more susceptible to the hepatotoxic effects of cyclosporin.

Regulation of Cbl molecular interactions by the co-receptor molecule CD43 in human T cells.

CD43, one of the most abundant glycoproteins on the T cell surface, has been implicated in selection and maturation of thymocytes and migration, adhesion, and activation of mature T cells. The adapter molecule Cbl has been shown to be a negative regulator of Ras. Furthermore, it may also regulate intracellular signaling through the formation of several multi-molecular complexes. Here we investigated the role of Cbl in the CD43-mediated signaling pathway in human T cells. Unlike T cell receptor signaling, the interaction of the adapter protein Cbl with Vav and phosphatidylinositol 3-kinase, resulting from CD43-specific signals, is independent of Cbl tyrosine phosphorylation, suggesting an alternative mechanism of interaction. CD43 signals induced a Cbl serine phosphorylation-dependent interaction with the tau-isoform of 14-3-3. protein. Protein kinase C-mediated Cbl serine phosphorylation was required for this interaction, because the PKC inhibitor RO-31-8220 prevented it, as well as 14-3-3 dimerization. Moreover, mutation of Cbl serine residues 619, 623, 639, and 642 abolished the interaction between Cbl and 14-3-3. Overexpression of Cbl in Jurkat cells inhibited the CD43-dependent activation of the mitogen-activated protein kinase (MAPK) pathway and AP-1 transcriptional activity, confirming nevertheless a negative role for Cbl in T cell signaling. However, under normal conditions, PKC activation resulting from CD43 engagement was required to activate the MAPK pathway, suggesting that phosphorylation of Cbl on serine residues by PKC and its association with 14-3-3 molecules may play a role in preventing the Cbl inhibitory effect on the Ras-MAPK pathway. These data suggest that by inducing its phosphorylation on serine residues, CD43-mediated signals may regulate the molecular associations and functions of the Cbl adapter protein.