[Thoracic surgery 2009]

Started with tuberculosis and developed in parallel with smoking and cancer and under the protection of anaesthesia, thoracic surgery appeared in the 1980's as a specialty with a difficult long-term survival. However, with the development of lung transplant, tracheal surgery, the appearance of video-assisted thoracic surgery, along with the confirmation that despite the excellent progress of chemoradiotherapy, surgery continues to be the best option for curing lung cancer, means that it is currently a specialty of great growth and a wider scope in the future.

[Severe aortic stenosis in a critical condition]

There is little information about patients with severe aortic stenosis (SAS) who require admission to acute care units. We studied 27 patients with SAS admitted in a tertiary hospital coronary care unit. The most frequent reasons for admission were severe heart failure (42%), acute coronary syndrome (39%) and cardiac arrest (8%). At a mean follow-up of 6.5 months, 11 patients died. Cumulative survival was 74±8%, 70±9%, and 62±10% at 7, 30 and 60 days, respectively. Out of the 27 patients, 13 (48%) underwent surgical intervention, these patients having lower Euroscore (13±11 vs. 34±18%, p=0.002) and higher survival (92±7% at 7, 30 and 60 days vs. 50±13%, 40±14% and 30±14%; p=0.002). Thus, patients with SAS who require hospitalization in the intensive care units constitute a very high risk population, with very high mortality, especially during the first week after admission and in patients who have not undergone surgery.

Magnetic structures of quaternary intermetallic borocarbides RCo(2)B(2)C (R = Dy, Ho, Er)

The magnetic structures of the title compounds have been studied by neutron diffraction. In contrast to the isomorphous RNi(2)B(2)C compounds, wherein a variety of exotic incommensurate modulated structures has been observed, the magnetic structure of ErCo(2)B(2)C is found to be a collinear antiferromagnet with [Formula: see text] while those of HoCo(2)B(2)C and DyCo(2)B(2)C are observed to be simple ferromagnets. For all studied compounds, the moments are found to be confined within the basal plane and their magnitudes are comparable to the values obtained from the low-temperature isothermal magnetization measurements. The absence of modulated magnetic structures in the RCo(2)B(2)C series (for ErCo(2)B(2)C, verified down to 50 mK) is attributed to the quenching of the Fermi surface nesting features.

Effects of different oocyte activation procedures on development and gene expression of porcine pre-implantation embryos

Among the factors that affect the efficiency of somatic cell nuclear transfer (SCNT) in pigs, the activation protocol is the most variable among the current SCNT procedures. The aim of this study is focused on defining an efficient activation treatment of porcine oocytes. In Experiment 1, we studied the effects of nine different oocyte activation procedures (including chemical- and electrical-based treatments) on parthenogenetic embryo development. In Experiment 2, we studied the effect of the more efficient activation procedures on the gene expression profile of Oct4 and Igf2r in parthenogenetic blastocysts. In conclusion, ionomycin as a first calcium stimulus is not able to activate porcine oocytes efficiently in comparison with electric procedures. Electrical treatments with 6-DMAP significantly increased the level of Oct4 expression, whereas the single and double pulse treatments alone maintained the same profile as the IVF group.

Current pharmacological approach to restore endothelial dysfunction

Endothelial dysfunction is characterized by an impairment of endothelium-dependent vasodilatation. It has been linked to each of the known atherogenic risk factors, including diabetes mellitus, hypertension, dyslipidaemia, cigarette smoking, menopause, etc. A number of recent studies have shown that the severity of endothelial dysfunction correlates with the development of coronary artery disease and predicts future cardiovascular events. Therefore, these findings strengthen the hypothesis that endothelial dysfunction may be an early stage of coronary atherosclerosis. This phenomenon primarily reflects an imbalance between the vasodilating (nitric oxide) and vasoconstrictor agents (endothelin-1). Several invasive (intracoronary or intrabrachial infusions of vasoacting agents) and non-invasive techniques (assessment of flow mediated vasodilatation in the brachial artery by ultrasound) have been developed during the last few years to evaluate endothelial function in the coronary and peripheral circulation. This new methodology has allowed assessing the severity of the abnormalities in vascular function and their regression by several pharmacological and non-pharmacological interventions. It is likely that restoration of endothelial function can regress the atherosclerotic disease process and prevent future cardiovascular events. Most pharmacological interventions attempting to improve endothelial dysfunction targeted the risk factors linked to endothelial dysfunction: hypertension (ACE-inhibitors, calcium antagonists), dyslipidaemia (lipid-lowering agents) and menopause (estrogens). Nevertheless, several pharmacological agents have been suggested to achieve vascular protection through different mechanisms beyond their primary therapeutic actions: ACE-inhibitors, statins, third generation of beta-blockers (nebivolol), endothelium-derived nitric oxide synthesis (tetrahydrobiopterin, BH4) and antioxidants agents. In this review we will focus on the current pharmacological management of the endothelial dysfunction.

[Effect of intensive treatment with atorvastatin versus standard doses of statins on the risk of stroke. A meta-analysis from five randomized trials including 25,709 patients]

AIM

To evaluate the efficacy of intensive lipid lowering treatment with atorvastatin versus standard doses of statins (simvastatin, atorvastatin, lovastatin or pravastatin) on the risk of stroke, using meta-analytic techniques.

PATIENTS AND METHODS

The meta-analysis included 5 randomized trials that met the inclusion criteria: comparison between intensive atorvastatin treatment (atorvastatin 80 mg or target LDL < 70 mg/dL) and standard doses of statins, with a clinical follow-up of more than 12 months and stroke as clinical endpoint. TNT (n = 9,917) atorvastatin 80 mg vs. 10 mg; IDEAL (n = 8,888) atorvastatin 80 mg vs. simvastatin 20-40 mg; PROVE-IT (n = 4,162) atorvastatin 80 mg vs. pravastatin 40 mg; ALLIANCE (n = 2,442) atorvastatin 80 mg or target LDL < 70 mg/dL vs. standard treatment; and VBBS (n = 300) atorvastatin 80 mg vs. low dose lavastatin. The selected studies included secondary prevention patients (acute coronary syndrome, stable coronary disease and patients eligible for angioplasty). 25,709 patients were included (12,910 allocated to intensive atorvastatin treatment, and 12,799 to standard doses of statins). Stroke incidence, as reported from each trial, was compared between both treatments.

RESULTS

Out of the 25,709 patients, 713 (2.77%) suffered a stroke during follow-up. The incidence of stroke was significantly reduced with intensive atorvastatin treatment in comparison with conventional doses of statins: 2.52% (n = 325) vs. 3.03% (n = 388); relative risk = 0.83; 95% confidence interval = 0.72-0.96; p = 0.0121.

CONCLUSIONS

Intensive lipid lowering treatment with atorvastatin is associated with a 17% relative risk reduction of stroke in comparison with conventional doses of statins in secondary prevention population.

On the ferromagnetic structure of the intermetallic borocarbide TbCo(2)B(2)C

Based on magnetization, specific heat, magnetostriction and neutron-diffraction studies on single-crystal TbCo(2)B(2)C, it is found out that the paramagnetic properties, down to liquid nitrogen temperatures, are well described by a Curie-Weiss behavior of the Tb(3+) moments. Furthermore, below T(c) = 6.3 K, the Tb sublattice undergoes a ferromagnetic (FM) phase transition with the easy axis being along the (100) direction and, concomitantly, the unit cell undergoes a tetragonal-to-orthorhombic distortion. The manifestation of an FM state in TbCo(2)B(2)C is unique among all other isomorphous borocarbides, in particular TbNi(2)B(2)C (T(N) = 15 K, incommensurate modulated magnetic state) even though the Tb ions in both isomorphs have almost the same crystalline electric field properties. The difference among the magnetic modes of these Tb-based isomorphs is attributed to a difference in their exchange couplings which are in turn caused by a variation in their lattice parameters and in the position of their Fermi levels.

Effect of antidepressants on melatonin metabolite in depressed patients

Antidepressants increase melatonin levels, but it is still unclear whether this effect is related to the improvement of depressive symptoms or to unrelated pharmacological action of antidepressants. To answer this question, the effect of antidepressants on 6-sulphatoxymelatonin (aMT6s), the main melatonin urinary metabolite, was examined in drug-free depressed patients - most of them antidepressant-naive. aMT6s was evaluated in 34 depressed patients, before and after 8 weeks of placebo (n = 12) or antidepressant (n = 22; fluoxetine, duloxetine or Hypericum perforatum). Both groups showed an improvement of depressive symptoms after treatment compared to baseline (Hamilton Depression scores): 17.0 +/- 1.4 vs. 9.0 +/- 2.8, P = 0.007 for placebo, and 18.6 +/- 1.1 vs. 11.8 +/- 1.6, P < 0.001 for antidepressants). After treatment, aMT6s levels increased after antidepressants (P < 0.01), but not after placebo (P > 0.05). As depressive symptoms improved both in patients taking antidepressant and in those taking placebo, but an effect of antidepressants could only be seen in those taking antidepressants, we suggest that melatonin changes after antidepressants are more likely due to a pharmacological action of these drugs on melatonin secretion.

Pilot- and bench-scale testing of faecal indicator bacteria survival in marine beach sand near point sources

AIM

Factors affecting faecal indicator bacteria (FIB) and pathogen survival/persistence in sand remain largely unstudied. This work elucidates how biological and physical factors affect die-off in beach sand following sewage spills.

METHODS AND RESULTS

Solar disinfection with mechanical mixing was pilot-tested as a disinfection procedure after a large sewage spill in Los Angeles. Effects of solar exposure, mechanical mixing, predation and/or competition, season, and moisture were tested at bench scale. First-order decay constants for Escherichia coli ranged between -0.23 and -1.02 per day, and for enterococci between -0.5 and -1.0 per day. Desiccation was a dominant factor for E. coli but not enterococci inactivation. Effects of season were investigated through a comparison of experimental results from winter, spring, and fall.

CONCLUSIONS

Moisture was the dominant factor controlling E. coli inactivation kinetics. Initial microbial community and sand temperature were also important factors. Mechanical mixing, common in beach grooming, did not consistently reduce bacterial levels.

SIGNIFICANCE AND IMPACT OF THE STUDY

Inactivation rates are mainly dependent on moisture and high sand temperature. Chlorination was an effective disinfection treatment in sand microcosms inoculated with raw influent.

[Staphylococcus aureus bacteremia in Castellón General Hospital (2001-2005)]

OBJECTIVE

The aim of this study was to know the frequency of bacteremias produced by Staphylococcus aureus and the sensibility that strains showed, as well as the clinical characteristics of the patients.

METHOD

We retrospectively studied cases of S. aureus bacteremia detected in our hospital from 2001 to 2005 and also reviewed medical histories from patients during 2005.

RESULTS

A total of 295 cases of S. aureus bacteremia were detected in this study. Annual distributions of the cases were as follows: 35, 54, 62, 64 and 80. By gender, 62.7 % related to males and 37.3 % to females. A total of 58.6 % of the patients were admitted to medical services and 49 % were older than 65 years. Regarding resistance, 34 % of the strains showed resistance to oxacillin, 33 % to ciprofloxacin, 41 % to erythromycin and 4.4 % to gentamicin. In one-third of the patients, S. aureus was isolated in other samples, the catheter being the most common. A total of the 73.5 % of the patients had some baseline disease and the most frequent predisposing factor was the intravascular catheter. The bacteremias were nosocomial-acquired in 73.5 % of the cases.

CONCLUSIONS

In our hospital, S. aureus bacteremia and oxacillin resistance has been increasing over the years of this study.

Different contamination patterns of lineage I and II strains of Listeria monocytogenes in a Spanish broiler abattoir

The purpose of this study was to determine whether genetically similar or diverse strains of Listeria monocytogenes colonize the environment and carcasses in a single Spanish broiler abattoir over time. The study was composed of 5 surveys over a 1.5-yr period and included the monitoring of cleaning and disinfection procedures. Overall, a total of 212 samples were tested for the presence of L. monocytogenes, and 31% of the samples were found to be positive. Listeria monocytogenes was isolated from carcasses and product contact and noncontact sites in the evisceration and carcass classification areas of the abattoir. A total of 132 L. monocytogenes isolates were characterized by PCR-based serotyping and pulsed-field gel electrophoresis (PFGE) restriction analysis with the endonucleases ApaI and AscI. Molecular serotyping showed that L. monocytogenes isolates were of serotypes 1/2a and 1/2b. Isolates of serotype 1/2b (89.4%) were contaminating carcasses as well as environmental product contact and noncontact sites, whereas isolates of serotype 1/2a (10.6%) were recovered only from environmental product noncontact sites. A relatively low genetic diversity was found in this group of L. monocytogenes isolates from the abbatoir; only 14 different PFGE types (A1 to A14) were obtained. Nine pulsotypes belonging to serotype 1/2b (lineage I) were grouped in only one PFGE genetic cluster, whereas 5 pulsotypes belonging to serotype 1/2a (lineage II) were grouped into 4 PFGE genetic clusters. Two genetically related pulsotypes of serotype 1/2b (A1 and A2, 64.4% of the isolates) predominated and persisted in the abattoir. Our study indicated that a few strains of L. monocytogenes lineage I that were genetically very closely related might be specifically adapted to colonizing the evisceration zone of the abattoir and were predominant on carcasses over 1 yr. On the other hand, a genetically diverse group of lineage II strains were present in the abattoir environment, but never contaminated carcasses.

[Old donors in liver transplantation for chronic hepatitis C]

BACKGROUND

the natural history of recurrent hepatitis C after liver transplantation (LT) is extremely variable, with progression to allograft failure in a substantial proportion of patients. The identification of factors associated with this poorer outcome may improve results. While donor age has been identified as one of the most important factors, the actual options to modify this variable are limited.

OBJECTIVES

a) to describe the natural history of HCV(+) liver transplant recipients depending on donor age ( < or = 50 years), including clinical, biochemical, and histological outcomes; and b) to identify in the subgroup of organ recipients from aged donors (= 50 years) factors associated with an aggressive course.

METHODS

a retrospective study of clinical and histological data including protocol liver biopsies for 162 HCV (+) liver transplant patients between 1997 and 2001 with at least one year of follow-up. Aggressive recurrent hepatitis C was defined as a progression to fibrosis > 1 during the first year post-LT, development of a cholestatic form of recurrent hepatitis C, and /or graft failure due to HCV during the first five years post-LT. Factors analyzed as potentially associated with recurrent hepatitis C included: a) recipient-related: demographics (age, sex), pre-transplantation (hepatocellular carcinoma, Child-Pugh classification, history of alcohol, HBV serological markers, antiviral treatment, nutritional status, biochemical variables); b) donor-related: demographics (age, sex), cause of death, grade of steatosis defined as minimal vs. moderate-severe > 10%); c) surgery-related: cold preservation and rewarming time, duration of procedure, blood transfusion; and d) post-LT management-related: immunosuppression, liver enzymes in the first 14 days post-LT, acute hepatitis post-LT, surgical complications (vascular and/or biliary).

RESULTS

patients were divided into two groups according to donor age group 1 ( < 50 years), n = 83, 51%, and group 2 (= 50 years), n = 79, 49%). Median follow-up was 5 years (range: 3 months-8.5 years). Aggressive recurrent hepatitis C occurred significantly more frequently in the older donor group (64 vs. 20.5%, p < 0.0001). In this group, potent immunosuppression -triple and quadruple regimens- (p = 0.04) and acute hepatitis post-LT (p = 0.03) were the only variables associated with aggressive recurrence. Degree of donor steatosis was not associated with the prognosis of recurrent hepatitis C.

CONCLUSION

the use of aged donors is partly responsible for the accelerated progression of hepatitis C after LT. When old donors are used we should avoid over-immunosuppression, and probably evaluate antiviral therapy in those with acute recurrent hepatitis C.

Pharmacological approach of no-reflow phenomenon related with percutaneous coronary interventions

The no-reflow phenomenon (NRP) is characterized by an inadequate myocardial tissue perfusion in the presence of a patent epicardial coronary artery. It generally occurs after temporary occlusion of the artery causing myocardial ischemia and necrosis that persist after relief of the vessel occlusion, without evidence of epicardial mechanical obstruction. Currently, the main scenario of NRP is the setting of percutaneous coronary interventions (PCI), especially in patients with acute myocardial infarction or saphenous vein graft disease, and its occurrence is associated with adverse clinical outcomes. Pathophysiology of NRP is not fully understood but it seems to be related with microvascular damage. Several mechanisms have been involved, such as distal microembolization, interstitial and intracellular edema, coronary spasm and capillary plugging. Diagnosis of NRP is generally based on clinical and angiographic data. Several methods have been proposed for the assessment of NRP, such as electrocardiography, myocardial contrast echocardiography, contrast-enhanced magnetic resonance imaging, nuclear imaging or positron emission tomography, that have demonstrated additional prognostic value over angiography. There are different pharmacological and mechanical approaches for the prevention of NRP but none of them have demonstrated a clear efficacy. The treatment of established NRP is mainly based on the administration of coronary vasodilators, like adenosine, verapamil or nitroprusside, but clinical results are frequently disappointing. The objective of this review is to describe the state of the art of the pathophysiology, diagnosis and pharmacological management of NRP.

The -250G/A polymorphism in the hepatic lipase gene promoter influences the postprandial lipemic response in healthy men

BACKGROUND AND AIM

The -250G/A promoter polymorphism of the hepatic lipase gene has been associated with changes in the activity of the enzyme. We investigated whether this polymorphism modifies the postprandial response of triacylglycerol-rich lipoproteins (TRL) in young normolipemic males.

METHODS AND RESULTS

Fifty-one healthy apolipoprotein (apo) E3/E3 male volunteers (30 G/G and 21 carriers of the A allele) underwent a vitamin A fat-loading test and blood samples were drawn every hour until the 6th, and every 2h and 30 min until the 11th. Total plasma cholesterol and triacylglycerols (TG), as well as cholesterol, TG and retinyl palmitate (RP) in TRL, isolated by ultracentrifugation, were determined. Carriers of the A allele showed a higher response (P=0.008), a higher area under the curve (AUC; P=0.022) and a lower RP peak time (P=0.029) in small TRL during the postprandial response, as well as a lower peak time in total plasma TG levels (P=0.034) and large TRL-TG (P=0.033) than subjects who were homozygous for the G allele.

CONCLUSION

Our data indicate that the presence of the A allele in the -250G/A promoter polymorphism of the hepatic lipase gene is associated with a higher postprandial lipemic response.