Assessment of Fennel Oil Microfluidized Nanoemulsions Stabilization by Advanced Performance Xanthan Gum

In this work, nanoemulsion-based delivery system was developed by encapsulation of fennel essential oil. A response surface methodology was used to study the influence of the processing conditions in order to obtain monomodal nanoemulsions of fennel essential oil using the microchannel homogenization technique. Results showed that it was possible to obtain nanoemulsions with very narrow monomodal distributions that were homogeneous over the whole observation period (three months) when the appropriate mechanical energy was supplied by microfluidization at 14 MPa and 12 passes. Once the optimal processing condition was established, nanoemulsions were formulated with advanced performance xanthan gum, which was used as both viscosity modifier and emulsion stabilizer. As a result, more desirable results with enhanced physical stability and rheological properties were obtained. From the study of mechanical spectra as a function of aging time, the stability of the nanoemulsions weak gels was confirmed. The mechanical spectra as a function of hydrocolloid concentration revealed that the rheological properties are marked by the biopolymer network and could be modulated depending on the amount of added gum. Therefore, this research supports the role of advanced performance xanthan gum as a stabilizer of microfluidized fennel oil-in-water nanoemulsions. In addition, the results of this research could be useful to design and formulate functional oil-in-water nanoemulsions with potential application in the food industry for the delivery of nutraceuticals and antimicrobials.

Differences in cardiovascular mortality in smokers, past-smokers and non-smokers: findings from the FRENA registry

BACKGROUND

The influence of smoking on outcome in patients with coronary artery disease (CAD) is controversial. Even less is known about its influence in patients with cerebrovascular (CVD), or peripheral artery (PAD) disease.

PATIENTS AND METHODS

FRENA is an ongoing, observational registry of consecutive outpatients with symptomatic CAD, CVD, or PAD. We reviewed their cardiovascular mortality according to smoking status.

RESULTS

As of May 2008, 2501 patients had been enrolled in FRENA. Of these, 439 (18%) were current smokers, 1086 (43%) past-smokers, 976 (39%) had never smoked. Current- and past-smokers were 10 years younger, more often males, and more likely to have chronic lung disease, but had diabetes, hypertension, heart failure, or renal insufficiency less often than non-smokers. Over a mean follow-up of 14 months, 123 patients died (cardiovascular death, 68). On univariate analysis, current smokers had a significantly lower rate of cardiovascular death: 1.1 (95% CI: 0.4-2.4) per 100 patient-years in current smokers; 1.9 (95% CI: 1.2-2.8) in past-smokers; 3.5 (95% CI: 2.5-4.7) in non-smokers, with no differences between patients with CAD, CVD or PAD. Mean age at cardiovascular death was 82+/-6.4; 70+/-9.9 and 67+/-15 years, respectively. On multivariate analysis, smoking status was not independently associated with a lower risk for cardiovascular death.

CONCLUSIONS

Current and past-smokers with CAD, CVD or PAD had a less than half cardiovascular mortality than those who never smoked, but this may be explained by the confounding effect of additional variables. They died over 10 years younger than non-smokers.

Secondary Prevention of Arterial Disease in Very Elderly People: Results From a Prospective Registry (FRENA)

There is little information on the effectiveness of secondary prevention interventions in very elderly patients. In this article, the incidence of major cardiovascular events during a 12-month follow-up period in a series of consecutive patients with coronary, cerebrovascular, or peripheral artery disease is analyzed. As of October 2006, 1264 patients had been enrolled. Of these, 324 (26%) were ≥75 years of age. Their incidence rate of 22 events per 100 patient-years (95% CI, 17-28) was over 2-fold the 7.9 (95% CI, 6.2-10) found in those <75 years of age. Among them, only chronic heart failure and diabetes were independently associated with an increased risk for major events, whereas the use of angiotensin II antagonists was associated with a lower risk. Patients ≥75 years of age had an over 2-fold higher incidence of major cardiovascular events. The use of angiotensin II antagonists was associated with a lower risk.

Towards a molecular genetic system for the pathogenic fungus Paracoccidioides brasiliensis

We herein report the development of a molecular toolbox for the dimorphic fungus Paracoccidioides brasiliensis, specifically a more efficient transformation and a gene expression system. We evaluated several parameters that influence Agrobacterium tumefaciens-mediated transformation (ATMT), such as co-cultivation conditions and host cell susceptibility. Our results show that cellular recovery and air drying of A. tumefaciens:P. brasiliensis mixtures are essential for ATMT. Overall, our data indicate a transformation efficiency of 78+/-9 transformants/co-cultivation (5+/-1 transformants/10(6) target cells). P. brasiliensis GFP-expressing isolates were also constructed by insertion of the GFP gene under the control of several fungal promoters. RT-PCR, epifluorescence microscopy and flow cytometry analysis revealed Gfp visualization for all studied promoters but without significant differences in fluorescence and gene expression levels. Moreover, we present evidence for the occurrence of random single gene copy integration per haploid nuclei and the generation of homokaryon progeny, relevant for the future use in targeted mutagenesis and linking mutations to phenotypes.

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: Flow cytometry and GP43 sequence analysis

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus.

New insights into the cell cycle profile of Paracoccidioides brasiliensis

The present work focuses on the analysis of cell cycle progression of Paracoccidioides brasiliensis yeast cells under different environmental conditions. We optimized a flow cytometric technique for cell cycle profile analysis based on high resolution measurements of nuclear DNA. Exponentially growing cells in poor-defined or rich-complex nutritional environments showed an increased percentage of daughter cells in accordance with the fungus' multiple budding and high growth rate. During the stationary growth-phase cell cycle progression in rich-complex medium was characterized by an accumulation of cells with higher DNA content or pseudohyphae-like structures, whereas in poor-defined medium arrested cells mainly displayed two DNA contents. Furthermore, the fungicide benomyl induced an arrest of the cell cycle with accumulation of cells presenting high and varying DNA contents, consistent with this fungus' unique pattern of cellular division. Altogether, our findings seem to indicate that P. brasiliensis may possess alternative control mechanisms during cell growth to manage multiple budding and its multinucleate nature.

One-Anastomosis Gastric Bypass by Laparoscopy: Results of the First 209 Patients

BACKGROUND

One-Anastomosis Gastric Bypass (OAGB) by laparoscopy consists of constructing a divided 25-ml (estimated) gastric pouch between the esophago-gastric junction and the crow's foot level, parallel to the lesser curvature, which is anastomosed latero-laterally to a jejunal loop 200 cm distal to the ligament of Treitz.

METHODS

The results of our first 209 OAGB patients operated from July 2002 to June 2004 are reported. Mean age was 41 years (14-66), BMI 48 (39-86) and mean excess body weight 66 kg (35-220). In 144 patients, OAGB was the only operation performed, and in 61 patients it was accompanied by other surgery (18 cholecystectomies, 5 incisional hernia repairs, and 38 adhesiolysis), and in 4 patients a restrictive bariatric operation had been performed previously.

RESULTS

2 patients (0.9%) were converted to open surgery due to uncontrollable bleeding. 3 patients (1.4%) needed re-operation in the immediate postoperative period. 5 patients (2.3%) needed prolonged hospital stay due to acute pancreatitis in 1 and anastomotic leakage in 4, all resolving with conservative treatment. 2 patients died (0.9%), 1 from fulminant pulmonary thromboembolism and 1 from nosocomial pneumonia. Long-term complications have occurred in only 2 patients who developed clinically significant iron-deficiency anemia. Mean excess weight loss was 75% after 1 year and >80% at 2 years.

CONCLUSION

OAGB is a simple, safe and effective operation with less perioperative risk than conventional gastric bypass, quicker return to normal activities, and better quality of life.

Phylogeographical insights into the origins of the Squalius alburnoides complex via multiple hybridization events

The origin, the phylogeographical structure and divergence times of hybridrogenetic Squalius alburnoides complex were analysed based on the complete mitochondrial cytochrome b gene (1140 pb). The molecular phylogenetic analyses suggest that the S. alburnoides complex has at least five asexual lineages of independent origin. The events that produced this ancestral hybridization took place over a long period of time. There have been multiple hybridization events throughout time, beginning in the upper Pliocene and probably continuing into the present. Increased humidity caused by climate changes in the Pliocene, along with tectonic lifting and vasculation of the Iberian Peninsula, led to the formation of current river drainages which, in turn, contributed to these hybridization events. We postulate that the Northwestern (Mondego and Douro) and the Southwest (Quarteira) drainages of the Iberian Peninsula delimited the border of the maternal ancestral distribution and that vicariant events led to the disappearance of the maternal ancestor in these regions, leaving today only the hybrid species. Two hypotheses have been suggested to explain the similarities between the mtDNA diversity observed in S. alburnoides and its maternal ancestor (S. pyrenaicus). The first hypothesizes that mtDNA similarity results from the recent extinction of the paternal ancestor, while the other postulates that: 'reconstituted non hybrid males' assumed the place of the extinct bisexual paternal ancestor and produced new hybridizations with S. pyrenaicus females.

Haplotype diversity and phylogenetic relationships among the Iberian barbels (Barbus, Cyprinidae) reveal two evolutionary lineages

The phylogenetic relationships and haplotype diversity of all Iberian barbels were examined by analyzing the complete mitochondrial cytochrome b gene sequence (1141 bp) of 72 specimens from 59 Iberian localities. Phylogenetic findings demonstrated a clear distinction between two mitochondrial lineages and confirmed the existence of two previously considered subgenera: Barbus and Luciobarbus: The first subgenus, Barbus, is represented on the Iberian Peninsula by Barbus haasi and Barbus meridionalis. The second subgenus, Luciobarbus, includes the remaining endemic Iberian species: Barbus comizo, Barbus bocagei, Barbus microcephalus, Barbus sclateri, Barbus guiraonis, and Barbus graellsii. Mean haplotype divergence between these subgenera was 10.40%, providing evidence of a clear subdivision within the Iberian barbels. Our results conflict with those reported in a recent study, based on 307 cytochrome b base pairs, that failed to identify any division within the genus Barbus in the Iberian Peninsula. The inclusion of nine further species belonging to this genus (used as outgroups) allowed us to establish a closer relationship of the Iberian species of the subgenus Barbus with other European taxa than with the Iberian Luciobarbus, which was found to cluster with North African, Caucasian, and Greek species. At the population level, no biogeographic structure was shown by specimens of each species (only 5.98% of the variation was attributable to differences among populations of each species). Given the discrete amount of divergence found among the Luciobarbus species, the formation of current hydrographic basins during the Plio-Pleistocene seems to have played a major role in their isolation and evolution.

Nuclear and mitochondrial data reveal high genetic divergence among Atlantic and Mediterranean populations of the Iberian killifish Aphanius iberus (Teleostei: Cyprinodontidae)

The molecular divergence and phylogenetic relationships of the Iberian populations of Aphanius iberus were established using allozymes and the complete cytochrome b gene sequence. Congruent results were found with both nuclear and mitochondrial molecular markers. The Mediterranean and Atlantic populations are clearly differentiated into two independent lineages. Their high molecular divergence suggests an early isolation, and the absence of gene flow among the populations indicates their independent evolution. The nuclear and mitochondrial data reveal monophyletic clustering of the two geographical lineages, but provide weak support for the population relationships. However, the mitochondrial results differentiated the Villena population as a distinct mitochondrial unit within the Mediterranean group. Geographically broad studies across the distribution range of A. iberus have helped to elucidate the patterns of diversification of this species. The genetic divergence found between the Atlantic and the Mediterranean populations is of the same order as those found among recognized species of cyprinodontids. The identification of two discrete evolutionary lineages has important implications for the conservation of this species, since its recovery requires the recognition and preservation of natural diversity. The Mediterranean and Atlantic lineages should be managed separately to avoid loss of their genetic identity, and the genetic uniqueness of the populations should be preserved by using wild stocks as the source of genetic diversity in captive breeding programmes.

[Coagulant activity of factor VII (FVIIc) in the elderly with ischemic heart disease]

BACKGROUND

The coagulant activity of factor VII increases with age and is a risk factor in middle aged subjects. Its role in elderly people is still unknown. The aim of this study was to evaluate whether or not FVIIc is a risk factor in such population.

PATIENTS AND METHOD

STUDY DESIGN

cases and controls study. The group of cases consisted of 79 subjects fulfilling the following criteria: a) age between 65 and 85 years, and b) admission in the Valle de los Pedroches Hospital of Pozoblanco (Córdoba, Spain) due to a myocardial infarction and/or unstable angina, 2 or 6 months before their enrollment. The control group consisted of 81 subjects of similar age, chosen at random from the municipal registry, and excluding those with coronary heart disease. Factor VIIc was measured by conventional methods. Plasma samples were diluted with deficient plasma in FVIIc, and coagulation times were measured after adding thromboplastin and calcium. The measures were compared with a <<control>> plasma and the results were presented as a percentage.

RESULTS

There were no significant differences in the FVIIc between cases (118.3 [SD 22.2]) and controls (116.5 [24.4]; p = 0.630) in the total group. When classified according to their age, it was observed that within the group of more than 75 years old, cases had a higher FVIIc than controls (124.1 [18.2] vs 113.3 [23.5]; p < 0. 05). When the classification was carried out according to sex, male presented similar results than the total group. Bivariable analysis showed, in subjects with coronary diseases, that FVIIc was related to total cholesterol, cLDL, apoprotein B, body mass index, HbA1c, and age. Factors related to FVIIc in the multivariable analysis were basal glucose serum level, body mass index; cHDL was negatively related.

CONCLUSIONS

FVIIc is higher in very old subjects with coronary diseases so it may be a significant coronary risk factor in this age group.

Antithrombotic potential of olive oil administration in rabbits with elevated cholesterol

Olive oil is the main source of dietary fatty acids in the Mediterranean region. The objective of this study was to evaluate the effect of dietary supplementation with virgin olive oil in an experimental model with rabbits fed an atherogenic diet (saturated fat 48% of total fat). Four different groups of 10 animals each were studied: (1) normolipemic diet (NLD), (2) atherogenic diet or saturated fatty acid-enriched diet (SFAED), (3) NLD with 15% olive oil (NLD+OLIV), and (4) SFAED with 15% virgin olive oil (SFAED+OLIV). The animals were fed the experimental diets for 6 weeks, after which we determined serum lipid profile (total cholesterol, HDL-cholesterol, and triglycerides), platelet aggregation, platelet thromboxane B(2), aortic prostacyclin, and platelet and vascular lipid peroxidation. Scanning electron microscopic images of the vascular endothelium were studied, as were morphometric parameters in the arterial wall and thrombogenicity of the subendothelium (annular perfusion chamber). Animals fed the SFAED showed platelet hyperactivity and increased subendothelial thrombogenicity. Animals fed the SFAED+OLIV showed, compared with the SFAED group, an improved lipid profile with decreased platelet hyperactivity and subendothelial thrombogenicity and less severe morphological lesions of the endothelium and vascular wall. We conclude that supplementation of the SFAED with 15% olive oil reduced vascular thrombogenicity and platelet activation in rabbits. Although the percentage of olive oil in the diet was higher than the amount in the human diet, these results may be helpful in determining the effect of olive oil in the human thrombogenic system.

Congruence between allozyme and cytochrome b gene sequence data in assessing genetic differentiation within the Iberian endemic Chondrostoma lemmingii (Pisces: cyprinidae)

To understand further the fragmentation of the hydrographical basins and the processes of divergence and speciation of freshwater fishes of the Iberian Peninsula, 10 populations of the Iberian endemic cyprinid Chondrostoma lemmingii were studied using 26 loci encoding 19 enzymes and the complete nucleotide sequence of the mitochondrial cytochrome b gene. Nuclear and mitochondrial DNA markers showed complete congruence in assessing the genetic differentiation among the samples analysed. This congruence was supported by a Mantel test in which a significant correlation (r=0.89) between Nei's genetic distances and sequence divergence (uncorrected p distances) was obtained. Diagnostic loci, Nei's genetic distances, and FST values, as well as the percentage of sequence divergence indicate that the Duero basin population accumulates the highest level of genetic differentiation. A moderate divergence was also observed among populations of the rest of the basins. Phenetic and phylogenetic relationships support the hypothesis that the differentiation process was not only due to hydrographical basin isolation but also due to an ancient endorrheism event, previous to hydrographical configuration, that could explain the marked differentiation of the Duero basin population.

Antiplatelet effect of the anaesthetic drug propofol: influence of red blood cells and leucocytes

1. The present study was designed to investigate the mechanism of the antiplatelet action of the anaesthetic propofol in vitro. 2. Human whole blood was incubated with different concentrations of propofol and its solvent Intralipid(R). We determined, platelet aggregometry in whole blood, platelet-enriched plasma (PRP), PRP plus red blood cells (RBC), and PRP plus leucocytes (LC); platelet production of thromboxane B2 (TxB2), ATP release by platelet dense granules, adenosine uptake by RBC, intraplatelet levels of cyclic adenosine monophosphate (cyclic AMP) and cyclic guanosine monophosphate (cyclic GMP), and LC production of nitric oxide (NO). 3. Propofol-induced inhibition of platelet aggregation was greater in whole blood (IC50 80 - 136 microM) than in PRP (IC50>600 microM), except when aggregation was induced by arachidonic acid, in which case the antiaggregatory effect of the anaesthetic was similar in both media (IC50 72 - 85 microM). Inhibition of platelet aggregation correlated significantly with inhibition of TxB2 synthesis (r2=0.83). Propofol also inhibited granular ATP release; this effect was greatest in whole blood. 4. The presence of RBC or LC increased the antiaggregatory effect of propofol, mainly when collagen was used as aggregating agent. Intralipid inhibited the uptake of adenosine by RBC, however this effect probably does not contribute significantly to its antiaggregatory effect. 5. The anaesthetic potentiated the NO-cyclic GMP pathway, mainly by increasing the synthesis of NO by LC. Intralipid had no effect on the NO-cyclic GMP pathway in the LC-platelet interaction. 6. Propofol inhibited platelet aggregation in human whole blood, possibly through the sum of the effects of Intralipid on the platelet-RBC interaction and the increased synthesis of NO by LC in the platelet-LC interaction.

The effect of propofol on oxidative stress in platelets from surgical patients

We investigated the changes in oxidative stress in platelets from surgical patients anesthetized with propofol. We studied 60 surgical patients (ASA physical status I and II) and 12 healthy volunteers. The patients were divided into three groups: anesthesia induced with an IV bolus dose of 4 mg/kg thiopental; anesthesia induced with an IV bolus dose of 2 mg/kg propofol; and total IV anesthesia (induction with propofol 2 mg/kg, infusion with propofol 10 mg/kg during the first 10 min, then 8 mg/kg for 10 min, and 6 mg/kg during the rest of the operation). Healthy volunteers were given an IV bolus dose of 10% fat emulsion (Intralipid). We measured the following variables in platelets: thiobarbituric acid reactive substances content, glutathione content, and glutathione peroxidase, reductase, and transferase activities. Thiopental did not modify any of the variables. Propofol decreased thiobarbituric acid reactive substances production by 25.7% and increased total glutathione content by 24.6%. The percentage of glutathione in oxidized form was 29.5% smaller in patients anesthetized with propofol. Glutathione peroxidase activity was 28.3% less, glutathione transferase was 44.5% more, and glutathione reductase was not significantly different. Intralipid had no effect on any of the variables. After infusion of propofol for 1 h, the effects were, in qualitative terms, the same as those seen after an initial bolus dose. In conclusion, our findings show that propofol has an antioxidant effect in humans. This effect may be beneficial in patients who have diseases in which free radicals play an important role.

IMPLICATIONS

This study demonstrates that propofol inhibits cellular oxidative damage, measured in platelets from surgical patients. Neither thiopental nor the fat emulsion (Intralipid) showed any effect. Moreover, propofol increased the antioxidant defense of glutathione. This could be applied in the protection of tissues from ischemic damage.

The in vitro effects of propofol on tissular oxidative stress in the rat

This study was designed to evaluate the in vitro effects of propofol on lipid peroxide formation and the glutathione antioxidant system in some tissues of Wistar rats (n = 8-10 per experiment). We measured thiobarbituric acid reactive substances (TBARS), and the activities of glutathione peroxidase (GSHpx), reductase (GSSGrd), and transferase (GSHtf). Propofol inhibited TBARS formation in a concentration-dependent manner. Etomidate and thiopental sodium 10(-6) to 10(-3) M had no effect. The effect of propofol was apparent immediately and was observed for up to 15-20 min after the start of TBARS formation. Propofol inhibited GSHpx activity by a maximum of 75.1%+/-8.4%, increased GSSGrd activity by a maximum of 188%+/-12.6%, and increased GSHtf activity by a maximum of 230%+/-20%. The solvent intralipid had no significant effect on any of the enzyme activities or on lipid peroxidation. We conclude that propofol not only inhibits lipid peroxidation, but also enhances the cellular antioxidant defense system. Propofol is thus able to prepare tissues against oxidative attack by boosting stores of reduced glutathione.

IMPLICATIONS

This study demonstrates that the anesthetic propofol increases one of the most important mechanisms against cellular damage, the glutathione system. The study was performed in several tissues of healthy rats. This could be applied as a possible protection in surgical patients suffering from an ischemic process (cerebrovascular disease, coronary ischemia, etc.).

Effect of dietary supplementation with evening primrose oil on vascular thrombogenesis in hyperlipemic rabbits

The dietary intake of saturated fatty acids affects arteriosclerosis. We studied the effect of supplementation (15% wt/wt) of a hyperlipemic diet (1.3% cholesterol) with evening primrose oil (Oenothera biennis) in four groups of 10 rabbits each. After 6 weeks the aortic endothelium was analyzed morphologically with scanning electron microscopy, and the arterial wall was studied with morphometric techniques and cell nucleus counts. Endothelial functioning was analyzed by measuring prostacyclin synthesis, and thrombogenicity of the subendothelium was studied by perfusion in a Baumgartner annular chamber. Evening primrose oil reduced hypercholesterolemia (from 29 +/- 3 to 12 +/- 2 nmol/l), increased HDL-cholesterol (from 0.5 +/- 0.06 to 0.8 +/- 0.09 nmol/l) and doubled prostacyclin synthesis (from 2.7 +/- 2 to 6.2 +/- 0.7 ng/mg aorta) in rabbits on the hyperlipemic diet, reduced subendothelial surface occupied by platelets (from 6.9 +/- 0.4 to 4.8 +/- 0.3%), and reduced human platelet adhesion on the subendothelium (from 53.3 +/- 6% to 38 +/- 8%, respect to total occupation). Morphological analyses showed that evening primrose oil diminished endothelial lesions caused by the atherogenic diet, reducing area of the arterial wall (from 6.9 +/- 0.2 to 4.7 +/- 0.2 microm2 x 10(6)) and the degree of neointimal proliferation (from 0.6 +/- 0.02 to 0.4 +/- 0.09 microm2 x 10(6)). We conclude that in our experimental model, this dietary supplement enhanced the antithrombotic capacity of the endothelium, reduced subendothelial thrombogenicity, and diminished the extent of vascular wall lesions caused by the hyperlipemic diet.

Effect of evening primrose oil on platelet aggregation in rabbits fed an atherogenic diet

Evening primrose oil (Oenothera biennis) is a rich source of omega-6 series fatty acids. We report here the effects of dietary supplementation with evening primrose oil (EPO) on platelet aggregation as the main factor in arterial thrombus formation in an experimental model of atherogenesis in rabbits. A total of 40 male white New Zealand rabbits were divided into four groups (n = 10 animals/group): 1: normal diet, 2: atherogenic diet (ATD), 3: normal diet enriched with 15% EPO, 4: ATD + EPO. Each group was kept on the diet for 6 weeks. We determined serum lipid profile, platelet aggregation in whole blood, platelet thromboxane B2 production and platelet lipid peroxides. The atherogenic diet increased platelet aggregation (135% when ADP was used, and 185% when collagen was used as the inducer). Evening primrose oil reduced hyperaggregation to the values obtained in rabbits fed with the normal diet. Thromboxane synthesis was increased from 0.18 to 2.28 nmol/10(9) platelets); EPO reduced this value to 1.38 nmol/10(9) platelets. Lipid peroxides were increased by ATD from 0.27 to 0.81 nmol/10(8) platelets; EPO prevented this increase (0.35 nmol/10(8) platelets). In conclusion, EPO reduced platelet hyperaggregability in rabbits fed an atherogenic diet.

Hybridogenetic reproduction and maternal ancestry of polyploid Iberian fish: the Tropidophoxinellus alburnoides complex

Iberian minnows collectively known as the Tropidophoxinellus alburnoides Steindachner complex comprise diploid and polyploid forms with highly female biased sex ratios. Previous investigators suggested that all-female clonal reproduction and interspecific hybridization may occur in this complex. We examined nuclear (allozymes) and cytoplasmic genes (mtDNA) to assess the evolutionary origins, relationships, and reproductive modes of T. alburnoides from western Spain. The multi-locus allozyme data clearly revealed the hybrid nature of all polyploid forms of this fish and some diploid forms as well. Diagnostic markers identified fish from the genus Leuciscus as the paternal ancestor of hybrids in the Duero and Guadiana River Basins. Additionally, analysis of nuclear markers revealed that hybridogenetic reproduction occurs in the diploid and triploid hybrids. The hybrids fully express the paternal Leuciscus genome and then discard it during oogenesis. Hybridogenetic ova contain only maternal nuclear genes and mtDNA from a non-hybrid T. alburnoides ancestor. Apparently diploid and triploid hybrids of T. alburnoides persist as sperm parasites on males of a sexually reproducing Leuciscus host species.

Propofol inhibits in vitro platelet aggregation in human whole blood

To help clarify the mechanism of propofol-induced vasodilation, we investigated whether propofol, at concentrations ranging from 10(-6) to 10(-3) M, inhibited platelet aggregation in human whole blood. Propofol inhibited platelet aggregation induced by adenosine diphosphate, collagen, or arachidonic acid in a concentration-dependent manner, with a 50% inhibited concentration (micromol/L) of 136 +/- 9.8 for adenosine diphosphate, 77.8 +/- 6.6 for collagen, and 71.8 +/- 5.4 for arachidonic acid. In platelet-rich plasma, propofol had no significant antiaggregant effect except when arachidonic acid was used as the aggregant (50% inhibited concentration 105 +/- 9.9 micromol/L). The antiaggregant effect of propofol in platelet-rich plasma was increased in the presence of red blood cells or leukocytes in a cell number-dependent manner. We conclude that propofol reduces the platelet activity in human whole blood in vitro.

Effect of fentanyl on cardiac automaticity and conduction: direct or mediated action?

The effects of fentanyl at a dose of 100 micrograms.kg-1 on cardiac automaticity, refractoriness and conduction have been studied in a model of heterotopic heart transplantation which combines a denervated heart (donor) and a non-denervated heart (recipient) in each of 20 dogs employed. Once the surgical procedure had been completed, cycle length, sinoatrial conduction time, antegrade and retrograde A-V node block points, cycle length at which 1:1 conduction ceases to exist and the antegrade effective refractory period of the A-V node and ventricles were measured. These parameters were determined in hearts both in the basal situation and 10 min after fentanyl injection. In the recipient organs, fentanyl produced statistically significant prolongation of cycle length, sinoatrial conduction time, antegrade block point and antegrade effective refractory periods of the A-V node and ventricles, with respect to the basal situation (P less than 0.01 for all these parameters); in 20% of cases, a complete A-V block was produced. In the donor hearts (denervated), prolongations of cycle length (P less than 0.01) and the antegrade block point (P less than 0.05), as compared with the basal situation, were recorded, but no other modifications were detected. To test whether these effects were due to the action of fentanyl, 10 animals were subsequently injected with naloxone, an agent which reverted the reported changes, although in the recipient organs, there persisted a slight prolongation of the cycle length with respect to basal measurements (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in anorectal function after anterior resection for cancer of the rectum

We have evaluated by means of a clinical and functional study the alterations in anorectal function of a group of 50 consecutive patients who have undergone an anterior resection of the rectum. Results are correlated with the anastomosis location and the time passed after the operation. According to research data this operation changes the patient's defaecation habits and the manometric and radiological parameters of anorectal function. These alterations are more evident in patients with a low anastomosis. The qualitative characteristics of defaecation did not change significantly in relation to the time passed since operation. However, there was a significant increase in compliance 6 months after operation, and the threshold rectal volume and the maximum tolerated volume also showed a significant increase 12 months following operation.

Colohepatic fistula due to hydatid disease. Report of a case

A patient with colohepatic fistula due to hydatid disease is reported. Only two similar cases have been described in the medical literature. This case illustrates that medical treatment with mebendazole is ineffective.

Partial monosomy 6q(q15q21) by de novo interstitial deletion

A partial monosomy 6q derived from a de novo 6q (q15q21) deletion, was seen in an infant male with mental retardation, odd facies and feeding difficulties.