Expressed sequence tags (ESTs) from immune tissues of turbot (Scophthalmus maximus) challenged with pathogens

Background

The turbot (Scophthalmus maximus; Scophthalmidae; Pleuronectiformes) is a flatfish species of great relevance for marine aquaculture in Europe. In contrast to other cultured flatfish, very few genomic resources are available in this species. Aeromonas salmonicida and Philasterides dicentrarchi are two pathogens that affect turbot culture causing serious economic losses to the turbot industry. Little is known about the molecular mechanisms for disease resistance and host-pathogen interactions in this species. In this work, thousands of ESTs for functional genomic studies and potential markers linked to ESTs for mapping (microsatellites and single nucleotide polymorphisms (SNPs)) are provided. This information enabled us to obtain a preliminary view of regulated genes in response to these pathogens and it constitutes the basis for subsequent and more accurate microarray analysis.

Results

A total of 12584 cDNAs partially sequenced from three different cDNA libraries of turbot (Scophthalmus maximus) infected with Aeromonas salmonicida, Philasterides dicentrarchi and from healthy fish were analyzed. Three immune-relevant tissues (liver, spleen and head kidney) were sampled at several time points in the infection process for library construction. The sequences were processed into 9256 high-quality sequences, which constituted the source for the turbot EST database. Clustering and assembly of these sequences, revealed 3482 different putative transcripts, 1073 contigs and 2409 singletons. BLAST searches with public databases detected significant similarity (e-value ≤ 1e-5) in 1766 (50.7%) sequences and 816 of them (23.4%) could be functionally annotated. Two hundred three of these genes (24.9%), encoding for defence/immune-related proteins, were mostly identified for the first time in turbot. Some ESTs showed significant differences in the number of transcripts when comparing the three libraries, suggesting regulation in response to these pathogens. A total of 191 microsatellites, with 104 having sufficient flanking sequences for primer design, and 1158 putative SNPs were identified from these EST resources in turbot.

Conclusion

A collection of 9256 high-quality ESTs was generated representing 3482 unique turbot sequences. A large proportion of defence/immune-related genes were identified, many of them regulated in response to specific pathogens. Putative microsatellites and SNPs were identified. These genome resources constitute the basis to develop a microarray for functional genomics studies and marker validation for genetic linkage and QTL analysis in turbot.

Characterization of EST-derived microsatellites for gene mapping and evolutionary genomics in turbot

The detection of microsatellite sequences within expressed sequence tags (ESTs) connects potential markers with specific genes, generating type I markers. We have developed and mapped by linkage analysis a set of EST-derived microsatellites in the turbot, Scophthalmus maximus. One hundred and ninety-one microsatellites were identified from 9256 turbot ESTs. Primer design was possible with 98 microsatellites. After genotyping 25 wild turbot and the parents of two reference families for linkage analysis, 43 EST-derived microsatellites were selected because they met technical and polymorphism criteria. A final set of 31 EST-derived microsatellites could be mapped to 17 linkage groups of the turbot consensus map based on 242 anonymous microsatellites. Twenty-four microsatellite-containing ESTs were functionally annotated, confirming them as type I markers. Nineteen were mapped in the turbot consensus map. These EST-derived microsatellites constitute useful tools for genome scanning of turbot populations, marker-assisted selection programmes and comparative mapping.

[How much should dialysis time be increased when catheters are used?]

The use of central catheters in hemodialysis patients as a permanent vascular access has increased during the last years, reaching numbers of around 7% of prevalent patients and between 25% of incident patients. Although the current catheters allow higher sanguineous flows with smaller incidence of infectious complications and dysfunction, the dose of dialysis that is reached is still inferior to that obtained with native arterio-venous fistula (AVF) and grafts. The aim of the present study was to evaluate the possible additional time supposed by dialysis using central venous catheters with respect to habitual vascular access as a consequence of the lesser blood flow (Qb) and the irregularity of its function (frequent lowering of the Qb and necessity of inverting the lines on many occasions). A total of 48 patients (31 men/17 women) with an average age of 61,6 +/- 14 years old (rank: 28-83), 20 with tunnelled catheter and the remaining with AVF, were included in the study. All the patients were dialyzed in the modality of high flux hemodialysis with a polisulphone of 1,9 m2 dialyzer, dialysis time of 240 minutes, dialysate flow 500 ml/min and monitors equipped with ionic dialysance (ID) with the objective of obtaining a Kt of 45 litres with each one of the different vascular accesses. The patients with AVF received 3 sessions, with variations of Qb to 300, 350 and 400 ml/min. The patients with tunnelled catheter received two sessions, to the maximum Qb, one with normal connection and other with inverted one. In the results obtained it is possible to emphasize that only the patients with AVF and 400 ml/min reached the objective of 45 L of Kt. The patients with AVF needed to increase 12 minutes of hemodialysis with a Qb of 350 ml/min and 28 minutes with a Qb of 300 ml/min; the catheters on normal position needed to increase 24 minutes and finally in the inverted catheters an increase of 59 minutes was necessary to reach the same Kt objective. We concluded that the patients dialyzed with central catheters on average needed to increase by 30 minutes the time of dialysis if the catheter worked in a normal position but 60 minutes if the arterio-venous lines were inverted so as to reach the minimum dose of dialysis.

[Kt as control and follow-up of the dose at a hemodialysis unit]

To ensure our patients are receiving an adequate dose in every dialysis session there must be a target to achieve this in the short or medium term. The incorporation during the last years of the ionic dialysance (ID) in the monitors, has provided monitoring of the dialysis dose in real time and in every dialysis session. Lowrie y cols., recommend monitoring the dose with Kt, recommending at least 40 L in women and 45 L in men or individualizing the dose according to the body surface area. The target of this study was to monitor the dose with Kt in every dialysis session for 3 months, and to compare it with the monthly blood test. 51 patients (58% of our hemodialysis unit), 32 men and 19 women, 60.7+/-14 years old, in the hemodialysis programme for 37.7+/-52 months, were dialysed with a monitor with IC. The etiology of their chronic renal failure was: 3 tubulo-interstitial nephropathy, 9 glomerulonephritis, 12 vascular disease, 7 polycystic kidney disease, 7 diabetic nephropathy and 13 unknown. 1,606 sessions were analysed during a 3 month period. Every patient was treated with the usual parameters of dialysis with 2.1 m2 cellulose diacetate (33.3%), 1.9 m2 polisulfone (33.3%) or 1.8 m2 helixone, dialysis time of 263+/-32 minutes, blood flow of 405+/-66, with dialysate flow of 712+/-138 and body weight of 66.7+/-14 kg. Initial ID, final ID and Kt were measured in each session. URR and Kt/V were obtained by means of a monthly blood test. The initial ID was 232+/-41 ml/min, the final ID was 197+/-44 ml/min, the mean of Kt determinations was 56.6+/-14 L, the mean of Kt/V was 1.98+/-0.5 and the mean of URR was 79.2+/-7%. Although all patients were treated with a minimum recommended dose of Kt/V and URR when we used the Kt according to gender, we observed that 31% of patients do not get the minimum dose prescribed (48.1+/-2.4 L), 34.4% of the men and 26.3% of the women. If we use the Kt individualized for the body surface area, we observe that 43.1% of the patients do not get the minimum dose prescribed with 4.6+/-3.4 L less than the dose prescribed. We conclude that the monitoring of dialysis dose with the Kt provides a better discrimination detecting that between 30 and 40% of the patients perhaps do not get an adequate dose for their gender or body surface area.

[Control of hypertension refractory to medical management by means of short daily hemodialysis]

Hypertension is a very frequent complication in patients in hemodialysis. A high percentage of the patients on standard hemodialysis remain hypertense in spite of intensive pharmacologic treatment. We presented the case of a hypertense patient with difficult control in spite of antihypertensive treatment with five drugs and several secondary complications. The change to a short daily hemodialysis was successful to hypertension control and allowed a gradual suspension of drugs.

Hepatic stellate cells and alcoholic liver disease

Liver fibrosis represents a significant health problem worldwide for which no effective therapy exists. A great deal of research has been carried out to understand the molecular mechanisms responsible for the development of liver fibrosis. Activated stellate cells are the primary cell type responsible for the production of collagen I, the key protein involved in the development of liver fibrosis. Excessive deposition of collagen I occurs along with impaired extracellular matrix remodeling. Following a fibrogenic stimulus stellate cells transform into an activated collagen type I-producing cell. Numerous changes in gene expression are associated with stellate cell activation, including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Activation of stellate cells is mediated by factors released from hepatocytes and Kupffer cells as they produce reactive oxygen species, nitric oxide, cytokines, growth factors, and cyclooxygenase and lipoxygenase metabolites, which provide pivotal paracrine effects in the liver milieu. Inhibition of stellate cell activation, proliferation, and the increased production of extracellular matrix (i.e. collagen type I) are therefore crucial steps for intervention in hepatic fibrogenesis.

Liver transduction with a simian virus 40 vector encoding insulin-like growth factor I reduces hepatic damage and the development of liver cirrhosis

Liver transplantation is the only treatment for advanced liver cirrhosis. Therapies halting the progression of the disease are urgently needed. Administration of recombinant insulin-like growth factor-I (rIGF-I) induces hepatoprotective effects in experimental cirrhosis. Therefore, we analyzed the efficacy of a recombinant simian virus 40 vector (rSV40) encoding IGF-I (rSVIGF-I) to prevent cirrhosis progression. First, transgene expression was evaluated in mice injected with rSV40 encoding luciferase, which showed long-term hepatic expression of the transgene. Interestingly, luciferase expression increased significantly in CCl(4)-damaged livers and upon IGF-I administration, thus liver injury and IGF-I expression from rSVIGF-I should favor transgene expression. rSVIGF-I therapeutic efficacy was studied in rats where liver cirrhosis was induced by CCl(4) inhalation during 36 weeks. At the end of the study, the hepatic levels of IGF-I and IGF-binding protein 3 were higher in rSVIGF-I-treated rats than in control cirrhotic animals. Cirrhotic rats treated with rSVIGF-I had reduced serum bilirubin, transaminases and liver fibrosis scores and increased hepatic expression of hepatocyte growth factor and STAT3alpha as compared to cirrhotic animals. Furthermore, cirrhotic animals showed testis atrophy and altered spermatogenesis, whereas testicular size and histology were normal in cirrhotic rats that received rSVIGF-I. Therefore, rSV40-mediated sustained expression of IGF-I in the liver slowed cirrhosis progression.

Effect of standard nicotinamide in the prevention of type 1 diabetes in first degree relatives of persons with type 1 diabetes

BACKGROUND

Nicotinamide has been used with success to prevent type 1 diabetes in animal models and humans. This vitamin B3 derivative has attracting effects on beta-cell protection and regeneration.

AIM/HYPOTHESIS

To evaluate the effect of standard nicotinamide administration on type 1 diabetes prevention in first degree relatives of persons with type 1 diabetes as well as on the concentrations of islet-cell-related autoantibodies, insulin secretion and peripheral sensitivity.

SUBJECTS AND METHODS

A randomized double-blind placebo controlled intervention trial was conducted in 40 first degree relatives of type 1 diabetic patients. Persistence of ICA ( >or= 10 JDF units) was among inclusion criteria. Participants were randomly allocated oral standard nicotinamide (1.2 g/m2) or placebo for 5 years. Groups were also stratified by age. Islet associated antibodies, fasting blood glucose, fasting plasma insulin concentrations, OGTT, IVGTT and HLA-DR genotyping were performed in all participants. The main criterion to stop treatment was type 1 diabetes development as defined by WHO.

RESULTS

Type 1 diabetes development frequencies were similar between the treatment groups. ICA frequencies at the end of the study, first phase insulin release, and insulin sensitivity did not differ between groups as well. None of the participants suffered from any adverse events described for nicotinamide.

CONCLUSIONS

Type 1 diabetes prevention trial using standard nicotinamide is feasible but fails to prevent or delay the disease onset at the dose we used.

Serum Protein S-100 Predicts Clinical Outcome in Patients with Melanoma Treated with Adjuvant Interferon – Comparison with Tyrosinase RT-PCR

OBJECTIVE

To study the clinical value of the determination of serum S-100 protein as a single tumor marker or in combination with tyrosinase RT-PCR in patients with melanoma receiving adjuvant interferon.

PATIENTS AND METHODS

Patients were tested for serum S-100 protein luminoimmunometric assay and for blood tyrosinase mRNA (RT-PCR), before starting interferon and every 2-3 months thereafter.

RESULTS

One hundred and six patients (stage IIA, 27; IIB, 19; III, 49; and IV, 11) were included in the study. Median follow-up was 51 months (range 2-76). In the univariate analysis, under treatment S-100 > or =0.15 microg/l and a positive RT-PCR correlated with a lower disease-free survival and overall survival (OS). In the multivariate analysis, clinical stage, under therapy positive RT-PCR and S-100 levels > or =0.15 mug/ml, were independent prognostic factors for OS. The hazard ratio for OS was 3.9 (95% CI, 1.67-9.15; p = 0.004) and 2.2 (95% CI, 1.05-4.6; p = 0.016) for S-100 > or =0.15 microg/l and positive RT-PCR, respectively. When both techniques where combined, a positive RT-PCR indicated a poorer clinical outcome only in patients with S-100 <0.15 microg/l.

CONCLUSIONS

S-100 > or =0.15 microg/l and a positive RT-PCR during adjuvant interferon therapy indicate a high risk of death in resected melanoma patients. S-100 determination has a higher positive predictive value than RT-PCR, while tyrosinase RT-PCR adds prognostic information in patients with S-100 <0.15 microg/l.

[Treatment with the placement of carotid stent of jugular-carotid fistula after the insertion of hemodialysis catheter]

The use of jugular temporary catheters as vascular access for hemodialysis, entails a risk of various complications. The most frequent problems are the arterial puncture and haematoma. However, there are other less frequent potentially serious complications, which constitute a therapeutic and diagnostic challenge for the nephrologists. We present a case of a patient that developed an acute renal failure in the context of cellulites for E. Coli treated with aminoglycosid, who required renal treatment with haemodialysis. After the placement of a polyurethane double-lumen catheter with ultrasound guidance at the level of the internal jugular vein, arterial blood streaming was observed through the lumen of the catheter. The angiographic study showed the tipo of the catheter placed at the level of the aortic arch. Ultrasound exam clearly despicted the track between the internal jugular vein and the internal carotid artery. An effective closing of the fistula was achieved with the placement of a covered stent-graft with the simultaneous withdrawal of the catheter. Reviewing the literature this is the first reported case of an iatrogenic jugulo-carotid fistula secundary to placement of hemodialysis catheter resolved by the implantation of carotid stent-graft.

Evaluation of the vehicle inspection/maintenance program in the Metropolitan Area of Mexico City

The Inspection/Maintenance Program in the Metropolitan Area of Mexico City (MAMC) mandates a test every 6 months for all gasoline motor vehicles as one of the strategies to decrease emissions of vehicular pollutants. FTP-75 and ASM procedures were performed in our facilities to a fleet of 108 in-use motor vehicles before and after the approval of the I/M mandatory test When our laboratory-simulated ASM data were compared with those of the official certificate, a large difference was observed between them. On the other hand, audits at the test-only centers indicate poor maintenance of the analytical instruments and dynamometers. On the basis of our FTP results, an estimation of the emissions change for the MAMC fleet shows a net 4% decrease in CO emissions, while total hydrocarbons and NOx increased 9 and 8%, respectively. Our results indicate that the I/M system in the MAMC lacks the technical capability and investment to ensure that software and hardware are properly maintained, calibrated, and upgraded. Sometimes limited attention is paid to ensure adequate training of inspectors, auditors, and quality control staff.

[Cardiovascular risk in patients with chronic renal failure. Patients in renal replacement therapy]

Dialysis patients constitute a high-risk subset of patients for developing cardiovascular disease, which accounts for nearly 50% of deaths. After stratification for age, race and gender, cardiovascular mortality is 10-20 times higher in dialysis patients than in the general population. Cardiovascular disease in this population cannot be fully explained by the high prevalence of classical cardiovascular risk factors (age, hypertension, diabetes, hyperlipidemia, smoking, etc.). Thus, the involvement of "new" cardiovascular risk factors (hyperhomocysteinemia, hyperfibrinogenemia, high lipoprotein (a) levels, oxidative stress, inflammation, etc.), and uremia-related factors (anemia, impaired calcium-phosphorus metabolism, hyperparathyroidism, accumulation of endogenous inhibitors of nitric oxide synthesis, etc.) has been also invoked to play a role in the increased cardiovascular risk in these patients. Endothelial dysfunction is the initial event in the development of atherosclerosis. Uremic patients exhibit an endothelial dysfunction, even before starting dialysis, which persists o is even aggravated under dialysis treatment. Uremic patients must be considered at high risk of developing cardiovascular disease. Thus cardiovascular risk factors in these patients should be managed early, aggressive and multifactorially in order to reduce their high cardiovascular morbidity and mortality.

The impact of managed care on the use of outpatient mental health and substance abuse services in Puerto Rico

This paper estimates the impact of managed care on use of mental health services by residents of low-income areas in Puerto Rico. A quasi-experimental design evaluates the impact of a low capitation rate on a minority population using three waves of data from a random community sample. Results indicate that two years after introducing managed care, privatization of mental health services had minimal impact on use. Advocates had hoped health care reform would increase access in comparison to access seen within the public system, while opponents feared profit motives would lead to decreased access. Neither forecast turned out to be correct. The question remains as to how to improve access for the poor with low capitation rates.

Rapid decline in renal function reflects reversibility and predicts the outcome after angioplasty in renal artery stenosis

Percutaneous transluminal renal angioplasty (PTRA) has a beneficial effect on renal function in some, but not all, patients with atheromatous renal artery stenosis. Our aim is to identify factors influencing clinical success after PTRA in this group of patients. Seventy-three patients undergoing PTRA were studied; 14 patients were excluded from final analysis because of restenosis. All patients had chronic renal failure secondary to vascular nephropathy and renal artery stenosis. The diagnosis of renal artery stenosis was based on carbon dioxide digital angiography showing greater than 60% luminal narrowing. The rate of renal failure progression was assessed by the slope of the regression line of serum creatinine versus time. At least three consecutive creatinine measurements before and after angioplasty were required for study entry. Response to PTRA was made by comparison of the slope before and after PTRA. The association of age, serum creatinine level, proteinuria, renal size, pre-PTRA slope value, diabetes, ischemic heart disease, peripheral vascular disease, and cerebrovascular disease with response to PTRA was assessed by multiple regression analysis, with changes in slope values as the dependent variable. Renal function improved in 34 of 59 patients (57.6%). Mean follow-up was 627 +/- 284 (SD) days. The slope of the reciprocal serum creatinine plot before PTRA was significantly associated with a favorable change in progression rate after PTRA (beta = -0.012; P = 0.004). A scatter plot showed a statistically significant inverse correlation between pre-PTRA slope values and post-PTRA slope changes (r = -0.46; P = 0.000). Rapidly progressive renal failure is associated with a favorable response on renal failure progression after PTRA in patients with vascular nephropathy and renal artery stenosis.

[Factors associated with the level of anxiety of nursing personnel taking care of HIV positive patients]

The objective of the study was to measure the level of HIV/AIDS related anxiety among hospital nursing staff and identify its determinants. Data were obtained through anonymous self administered questionnaire distributed to 222 nurses. The rasge anxiety and the HIV/AIDS attitudes were the most determinants of the anxiety level in the participants. Specifically, negative HIV/AIDS attitudes was associated with raise in state anxiety level, as well as high level of rasge anxiety was associated with high level of state anxiety. In conclusion, it is necessary to provide to the participants update trainings that included different aspects of HIV infection, as well as, anxiety management when caring for persons with HIV/AIDS.