In situ experiment to evaluate biochemical responses in the freshwater mussel Diplodon chilensis under anthropogenic eutrophication conditions

An in-situ experiment was performed to study metabolic responses of the freshwater mussel Diplodon chilensis to water contaminated by leachates from an open dump and cattle activity, in order to analyze both the effects of those contaminants on aquatic environments and the potential use of a native bivalve to evaluate the effects of anthropic influence and eutrophication. Bivalves from a reference site were cage-transplanted to a control site (site A) and to a temporal water pond (site B) over 30 and 60 periods. Water quality analyses revealed that the site B was affected by anthropogenic influence. Mussel's hemocytes from site B showed 50% lower reactive oxygen species production and 130% higher lysosomal membrane stability in the site B mussels. In addition, no oxidative stress was evident in gills, despite the elevated copper and iron concentrations recorded in the site B water samples (Cu_B = 0.3350 ± 0.0636 mg. L^-1vs. Cu_A = 0.0045 ± 0.0007 mg. L^-1; Fe_B = 3.8650 ± 0.4031 mg. L^-1vs. Fe_A = 0.0365 ± 0.0049 mg. L^-1). In contrast, the adductor muscle accumulated more Fe (~10-20-fold) than the gills and showed signs of oxidative stress, e.g. superoxide dismutase activity and TBARS levels were increased by 10% were 34%, respectively, in the site B compared with the site A after 60 days of exposure. Additionally, the adductor muscle showed signs of anaerobic metabolism activation. Cu is accumulated in gills from both sites' individuals, at 60 days, in concordance with the increase in the activity of the cu-containing enzyme cytochrome-c-oxidase. There was a reduction in the overall condition and digestive gland index in bivalves exposed at site B, associated with diminished levels of lipid and protein contents. Metal-pollution and eutrophication affects D. chilensis metabolism and is associated to tissue-specific exposure, anaerobic metabolism and general energetic condition depletion.

Effects of azinphos-methyl on enzymatic activity and cellular immune response in the hemolymph of the freshwater snail Chilina gibbosa

The use of a battery of biomarkers, especially those more closely related to species integrity, is desired for more complete ecotoxicological assessments of the effects of pesticide contamination on aquatic organisms. The phosphorodithioate azinphos-methyl has been intensively used in agriculture worldwide and have been found in the habitat of Chilina gibbosa, a freshwater snail endemic to South America. This snail has been proposed as a good model organism for ecotoxicity bioassays on the basis of studies focused mainly on enzymatic responses in whole tissue homogenates. Our aim was to evaluate the effect of an acute 48 h exposure to an environmental concentration of azinphos-methyl on C. gibbosa hemolymph enzymatic activity and cellular immune response. Our results show that cholinesterase activity was strongly inhibited (94%) in hemolymph of exposed snails. Carboxylesterase activity measured with p-nitrophenyl butyrate and glutathione S-transferase activity were augmented 47% and 89% respectively after exposure. No differences were found for hemolymph carboxylesterase activity measured with p-nitrophenyl acetate. These results differ from those reported for whole tissue homogenates and reveal that tissue-specific responses of enzymatic biomarkers exist in this species. Regarding immune cell response, hemocytes were identified for the first time for C. gibbosa. Their viability and phagocytic activity decreased after azinphos-methyl exposure although total number of circulating cells did not differ between treatments. We conclude that concentrations of azinphos-methyl that can be found in the environment can compromise both hemolymph cholinesterase activity and the immune system of C. gibbosa. Furthermore, we propose that carboxylesterase and glutathione S-transferase activities measured in hemolymph and hemocyte viability and phagocytic activity could be incorporated as sensitive biomarkers to evaluate the effects of pesticide exposure on this and related species.

Echocardiographic determination of resting haemodynamics and optimal positioning in term pregnant women

Optimal positioning for anaesthesia in pregnant women involves balancing the need for ideal tracheal intubation conditions (achieved by the head elevated ramped position), with the prevention of reduced cardiac output from aortocaval compression (achieved by left lateral pelvic tilt). No studies have examined the effect on cardiac output of left lateral pelvic tilt in the ramped position. We studied non-labouring, non-anaesthetised healthy term pregnant women who underwent baseline (left lateral decubitus) cardiac assessment using transthoracic echocardiography. We then compared cardiac output, maternal physiological variables, fetal heart rate and comfort scores in three positions: left lateral decubitus; ramped position with wedge; and ramped position alone. Thirty women completed the study. Mean (SD) age, gestation and body mass index were 33.5 (3.93) years, 38.5 (0.94) weeks and 29.0 (4.0) kg.m^-2 , respectively. Mean ejection fraction, left ventricular internal diameter and mitral valve E/e' were 55.2 (6.8) %, 4.70 (0.43) cm and 7.50 (1.82), respectively. There were no differences in cardiac output between the positions (p = 0.503). There were no differences in systolic (p = 0.955) or diastolic (p = 0.987) blood pressure, maternal heart rate (p = 0.133), oxygen saturation, respiratory rate (p = 0.964) or fetal heart rate (p = 0.361) between ramped with wedge and ramped alone positions. Left lateral decubitus was most comfortable (p = 0.001), however, there were no differences in comfort levels between ramped with wedge and ramped alone positions. The ramped position without left lateral tilt is safe and acceptable in non-labouring, non-anaesthetised, healthy term pregnant women. Left lateral pelvic tilt may be unnecessary in the head elevated ramped position in term pregnant women.

First experimental observations on melting and chemical modification of volcanic ash during lightning interaction

Electrification in volcanic ash plumes often leads to syn-eruptive lightning discharges. High temperatures in and around lightning plasma channels have the potential to chemically alter, re-melt, and possibly volatilize ash fragments in the eruption cloud. In this study, we experimentally simulate temperature conditions of volcanic lightning in the laboratory, and systematically investigate the effects of rapid melting on the morphology and chemical composition of ash. Samples of different size and composition are ejected towards an artificially generated electrical arc. Post-experiment ash morphologies include fully melted spheres, partially melted particles, agglomerates, and vesiculated particles. High-speed imaging reveals various processes occurring during the short lightning-ash interactions, such as particle melting and rounding, foaming, and explosive particle fragmentation. Chemical analyses of the flash-melted particles reveal considerable bulk loss of Cl, S, P and Na through thermal vaporization. Element distribution patterns suggest convection as a key process of element transport from the interior of the melt droplet to rim where volatiles are lost. Modeling the degree of sodium loss delivers maximum melt temperatures between 3290 and 3490 K. Our results imply that natural lighting strikes may be an important agent of syn-eruptive morphological and chemical processing of volcanic ash.

Modulation of immune and antioxidant responses by azinphos-methyl in the freshwater mussel Diplodon chilensis challenged with Escherichia coli

The aim of the present study was to characterize the immune response-total hemocyte number, cell type proportion, hemocyte viability, lysosomal membrane stability, phagocytic activity, cellular acid and alkaline phosphatase activity, and humoral bacteriolytic and phenoloxidase activity--in Diplodon chilensis exposed to 0.2 mg/L of azinphos-methyl (AZM), using Escherichia coli as immunological and pro-oxidant challenges. In addition, glutathione-S-transferase and lipid peroxidation thiobarbituric acid reactive substances were analyzed in gill tissue. Mussels from an unpolluted site were treated for 3 d as follows: 1) experimental control; 2) solvent effects control (acetone 0.01%); 3) bacterial challenge effects control (E. coli, 5 cells/mL × 10⁴ cells/mL); 4) pesticide effects control (AZM in acetone); 5) control for combined effects of solvent and bacterial challenge; and 6) exposed to AZM, then challenged with E. coli. The results showed increased granulocyte proportion and phagocytic activity. Partial reversion of deleterious effects of E. coli on lysosomal membranes was observed in mussels exposed to AZM and then challenged with E. coli. Total hemocyte number and humoral bacteriolytic activity were increased only by E. coli challenge. Acid phosphatase activity was increased by both E. coli and AZM, whereas the stimulating effect of E. coli on alkaline phosphatase activity was negatively modulated by AZM. Azinphos-methyl inhibited phenoloxidase activity regardless of the E. coli challenge. Gill glutathione-S-transferase activity was increased by E. coli treatment either alone or pretreated with acetone or AZM and by AZM alone. Thiobarbituric acid reactive substance levels were reduced by AZM alone or combined with the E. coli challenge and by acetone followed by the E. coli challenge. Both acetone and AZM seem to be important modulators of immune and antioxidant responses in D. chilensis. Environ Toxicol Chem 2017;36:1785-1794. © 2016 SETAC.

High Blood Pressure States in Children, Adolescents, and Young Adults Associate Accelerated Vascular Aging, with a Higher Impact in Females' Arterial Properties

The aims of the study were to determine (1) whether the presence of High blood pressure (HBP) states in the youth associate a steeper rate of age-related change in arterial geometrical and wall properties with respect to subjects with no previous cardiovascular risk factor (CRF) exposure, (2) in which parameters and in what magnitude, and (3) the existence of a gender-related difference in the impact of this condition on arterial properties. 300 individuals (mean/range: 15/4-29 years; 133 females) were included. Two groups were assembled: (1) Reference: nonprevious exposure to traditional CRF and (2) HBP: subjects with arterial hypertension and/or elevated blood pressure (BP) levels during the study. Additionally, HBP subjects were separated in BP-related subgroups. Measured parameters were (1) central (aortic) arterial BP and aortic pulse wave analysis parameters, (2) carotid and femoral artery local (pressure-strain elastic modulus) and regional (pulse wave velocity; PWV) stiffness, and (3) arterial diameters and carotid intima-media thickness (CIMT). Age-related changes in these parameters (absolute values and z-scores) were explored by obtaining simple linear regression models for each group. HBP presented a steeper rate of change (accelerated vascular aging; VA) for most of the parameters assessed, mainly in central (aortic) hemodynamics. VA increased as the HBP level got higher. Both males' and females' aging rates were affected by this condition, but females presented a more marked relative age-related increase with HBP exposure. HBP states in the youth gradually associate accelerated VA, with a progressive hemodynamic-structural-functional onset of damage, with females presenting a more marked relative HBP-associated arterial repercussion.

Children and Adolescent Obesity Associates with Pressure-Dependent and Age-Related Increase in Carotid and Femoral Arteries' Stiffness and Not in Brachial Artery, Indicative of Nonintrinsic Arterial Wall Alteration

Aim. To analyze if childhood obesity associates with changes in elastic, transitional, and/or muscular arteries' stiffness. Methods. 221 subjects (4-15 years, 92 females) were assigned to normal weight (NW, n = 137) or obesity (OB, n = 84) groups, considering their body mass index z-score. Age groups were defined: 4-8; 8-12; 12-15 years old. Carotid, femoral, and brachial artery local stiffness was determined through systodiastolic pressure-diameter and stress-strain relationships. To this end, arterial diameter and peripheral and aortic blood pressure (BP) levels and waveforms were recorded. Carotid-femoral, femoropedal, and carotid-radial pulse wave velocities were determined to evaluate aortic, lower-limb, and upper-limb regional arterial stiffness, respectively. Correlation analysis between stiffness parameters and BP was done. Results. Compared to NW, OB subjects showed higher peripheral and central BP and carotid and femoral stiffness, reaching statistical significance in subjects aged 12 and older. Arterial stiffness differences disappeared when levels were normalized for BP. There were no differences in intrinsic arterial wall stiffness (elastic modulus), BP stiffness relationships, and regional stiffness parameters. Conclusion. OB associates with BP-dependent and age-related increase in carotid and femoral (but not brachial) stiffness. Stiffness changes would not be explained by intrinsic arterial wall alterations but could be associated with the higher BP levels observed in obese children.

[Hybrid infrainguinal revascularization for critical limb ischemia]

The introduction of endovascular procedures in the routine of vascular surgery allowed for the expansion of therapeutic options in the diverse areas of vascular disease. Endoluminal revascularization can be regarded as a usefull complement of conventional surgical techniques. An above-knee femoro-popliteal bypass surgery ePTFE graft has been performed, followed by a sheath introduction on the graft body. This allows a simplified access to crural vessels, while providing efficient revascularization of the femoro-popliteal sector. Distal revascularization was performed using angioplasty and stenting when appropriate, as to insure continuous flux in at least one of the tibial or the peroneal arteries. The aim of this kind of procedure is to insure efficient femoro-popliteal revascularization and to achieve a run-off to the foot in at least one vessel. This type of intervention may be particularly attractive in Leriche-Fontaine's grade IV patients with no available autologous venous graft.

[Complex supraclavicular false aneurysm. Case report]

The authors report the clinical case of a 29 year-old caucasian male, previously healthy, victim of traffic accident with head and chest trauma, resulting in a prolonged stay (around 60 days) in an intensive care unit. After hospital discharge, the patient noticed a slow growing of a left supraclavicular pulsatile mass, associated with pain, both local and irradiating to the left arm. The diagnostic investigation revealed a complex false aneurysm with associated arterio-venous fistulae, dissecting cervical muscle planes and involving the braquial plexus. He was submitted to surgical intervention consisting in the ligation of a scapular afferent artery and ligation of communication to the internal jugular vein, with significant decrease in the intra-luminal blood flow velocity. He was subsequently submitted to percutaneous eco-guided thrombin injection under Valsalva manouver, with complete thrombosis of the false aneurysm. There was a quick resolution of the clinical complaints and a progressive reduction of the mass volume (6 month follow-up). A discussion is made on the main features of this entity, normally its etiopathogeny, surgical management and false aneurysm exclusion by means of eco-guided injection of thrombin.

Failure of an inactivated vaccine against porcine reproductive and respiratory syndrome to protect gilts against a heterologous challenge with PRRSV

This study was designed to evaluate the efficacy of an inactivated vaccine based on a European-type strain of porcine reproductive and respiratory syndrome virus (PRRSV) against the reproductive form of the syndrome in breeding gilts, and any congenital disease in their piglets. Five gilts were vaccinated twice, following the manufacturer's instructions, before they were inseminated. Nine additional gilts remained unvaccinated and served as positive (five gilts) and negative (four gilts) controls. A European wild-type strain genetically divergent from the vaccine strain was used to challenge the five vaccinated and five unvaccinated positive control gilts at 90 days' gestation. The vaccination of the five seronegative gilts did not produce any clinical signs or adverse reactions. However, the vaccine failed to prevent the clinical signs associated with PRRSV infection, viraemia after the challenge and transplacental infection of their piglets. The reproductive performance of the vaccinated gilts was similar to that of the unvaccinated positive controls, and there were no statistically significant differences in most of the parameters tested. However, the preweaning mortality of the piglets born to the vaccinated gilts was significantly lower than that of the piglets born to the positive control gilts.

[Valvular transposition in patients with ulcers of the lower limbs following post thrombotic syndromes]

Venous ulcers in patients with post thrombotic syndromes are complex situations with multiple therapeutic options. They are responsible for high morbidity rates, conservative treatment is very slow and recurrences are very common. Deep venous reconstructive surgery is an alternative, but it should be based on the morphologic and functional aspects of the venous system and only adopted after a very careful study, including venography. The authors describe a morphological "pattern", found in some of these patients and related to the competence of the saphenous femoral junction, rendering possible to perform a valvular transposition. Seven patients with post thrombotic ulcers who have been treated during the last 6 years in which the pattern already described was detect, underwent a transposition of the superficial femoral vein, to the great saphenous vein and when necessary complemented with skyn grafts. Before the operation all patients had ulcers with more than 3 cm in size (3.2-5.4 cm) and with more than 4 months duration (4-16 months). All ulcers healed in the postoperative period (mean time 28 days). All patients have been reevaluated in 2003 and it was diagnosed the thrombosis of two procedures, one of them with the recurrence of the ulcer who healed with conservative treatment. The authors consider this method as a very easy technique to perform, although rarely used, and a valid alternative in a highly selected group of patients.

Determination of triazines in water samples by high-performance liquid chromatography with diode-array detection

Triazines are widely used herbicides that can be detected in the environment at trace level. A preconcentration step is necessary to determinate them before analysis. In this study, carbonaceous and polymeric adsorbents are compared with C18 for the solid-phase extraction of simazine, atrazine, and propazine in water samples in order to quantitate their levels by high-performance liquid chromatography using photodiode-array detection.

Serum basic fibroblast growth factor levels in exercise-induced myocardial ischemia more likely a marker of endothelial dysfunction than a marker of ischemia?

Increased levels and activity of fibroblast growth factor (FGF) have been documented in a variety of diseases, including ischemia. Both acute coronary syndromes and exercise are situations that stimulate FGF release. Since experimental studies have demonstrated that FGFs are involved in myocardial preconditioning, it has been suggested that cardiac and circulating FGFs may play a cardioprotective role in ischemic diseases. However, the profile of basic FGF (bFGF) release during transient myocardial ischemia remains uncertain. We sought to determine whether circulating bFGF might be changed in patients with demonstrated coronary artery disease and evidence of ischemia in exercise scintigraphy (Isch +; n = 21). Serum from 22 age-matched patients with no coronary artery disease and no isotopic ischemia (Isch-) were used as controls. Three blood samples were obtained to determine bFGF at different times: baseline (bFGF-A); maximal exercise (bFGF-B), and isotopic redistribution (bFGF-C). An enzyme-linked immunoassay specific for bFGF was used (limit of detection, 1.0 pg/ml). Circulating bFGF was increased at maximal exercise in both Isch + and control patients. However, serum levels of bFGF were elevated up to more than two-fold in Isch-patients compared to Isch+ patients (8.67 +/- 2.10 pg/ml in Isch+ vs 17.83 +/- 2.97 pg/ml in Isch- patients; p<0.01). According to previous data, these findings suggest that bFGF serum levels could be considered more likely a marker of endothelial dysfunction occurring in patients with coronary artery disease, rather than a marker of acute ischemia. This situation could be different in the clinical setting of chronic myocardial ischemia.

[Tomographic studies of myocardial perfusion normality with 99m Tc-Tetrofosmin. Spanish multicenter study]

As a first phase in a nationwide multicenter study to obtain myocardial perfusion normality patterns, this work presents the study design and quality control methodology used to guarantee that the gammacameras fulfilled some minimum quality requirements. The following aspects were considered in the study design in order to guarantee the homogeneity and interchangeability of the results: creation and structure of the work group, data interchange system, data selection and acquisition, centralized archiving and processing, assessment system, study acceptance criteria and distribution of the results. To carry out the instrumental quality control, three phantom studies were established, one to control the rotation center, another to verify tomographic uniformity and a third to simulate the shape and orientation of the left ventricle. The three phantoms circulated through all of the 18 participating centers in this project, which corresponded to 19 gammacameras. Very strict guidelines had to be followed in the acquisition and processing of these phantom studies. If any camera and/or center did not fulfill the criteria established, it was advised of the problem detected in order to correct it. Once the defect was repaired, all the phantoms were sent again for verification. Uniformity of the rotation center was quantified by means of the eccentricity of a 360 degrees orbit, admitting up to a maximum of 10%. Tomographic uniformity was visually assessed, taking in account the number of slices with rings and their contrast and finally no artifacts could be present in the reconstructed study of the ventricle. The center of rotation was within limits in all the cameras except one case while the tomographic uniformity was incorrect in 6 cases. All the departments, except one, corrected the defects detected, and passed the acceptance test. The results made it possible to guarantee adequate homogeneity and instrumental quality in this multicenter study.

[Tomographic studies of myocardial perfusion normality with 99m Tc-Tetrofosmin. Spanish multicenter study]

This objective of this study was to obtain a pool of Myocardial Perfusion SPECTs with a 99mTetrofosmin stress/rest one day protocol in normal volunteers having a less than or equal to 5% likelihood of coronary artery disease that represents normalcy in the Spanish population. A total of 169 volunteers from 15 hospitals were studied. The volunteers were divided into 5 groups: Groups 1, 2 or 3 corresponding to men < 30 years (n = 33), men between 30 and 50 years (n = 32), or men > 50 years (n = 31); Groups 4 or 5: premenopausal (n = 38) or postmenopausal women (n = 35). A clinical history, physical examination, clinical laboratory parameters, echocardiography and a symptom limited exercise stress test were performed in all of them and had to be normal. The mean likelihood of coronary artery disease was 1.15 +/- 1.07%.Twenty-four segments were analyzed in each study and were classified into 5 grades of uptake (1 = normal, 2, 3, 4 = mild, moderate or severe defect and 5 = no uptake). Defects were then analyzed according to sex and location. Considering the stress and rest studies separately (8,112 segments), only 19 moderate and 75 mild defects were found, these corresponding to 16 volunteers, with more inferior defects in men and anterior defects in women. These data validate the normalcy of our population. A pool of Myocardial Perfusion SPECTs with a 99mTetrofosmin stress/rest one day protocol in normal volunteers that represents Spanish normal values was obtained.

Porcine reproductive and respiratory syndrome (PRRS) virus down-modulates TNF-alpha production in infected macrophages

The effect of porcine reproductive and respiratory syndrome (PRRS) virus infection on the synthesis and secretion of TNF-alpha and other pro-inflammatory cytokines by porcine alveolar macrophages (PAM) was investigated as well as the effect that TNF-alpha has on the replication of this virus. A clear reduction of phorbol myristate acetate (PMA)-induced expression of TNF-alpha mRNA was observed in cells incubated with PRRS virus. Moreover, the presence of PRRS virus also induced a decrease in IL-1 alpha and MIP-1 beta mRNAs expression with respect to PMA-stimulated uninfected cells. According to these results, exposure to the PRRS virus led to a reduction of the TNF-alpha protein in supernatants of PMA-stimulated PAM. On the other hand, addition of recombinant porcine TNF-alpha to cultures clearly reduced virus replication; however the addition of TNF-alpha to cultures containing IFN-alpha did not result in a further reduction of the produced by IFN-alpha alone. This indicates the lack of synergy in the effect of these cytokines on viral replication.

A Brevibacterium lactofermentum 16S rRNA gene used as target site for homologous recombination

Genes for rRNA are highly conserved and present in multiple copies in most prokaryotic organisms increasing the number of theoretical sites for homologous recombination. They might be targets for integration events between unrelated microorganisms providing that an efficient genetic transfer is present. We have used a plasmid containing a portion of the 16S rRNA gene from the rrnD operon of Brevibacterium lactofermentum to transform the same strain resulting in non-essential inactivation of various rrn operons. Integration of the transforming DNA occurs in all cases. The system may be used to test possible gene transfer at least among closely related strains and is of great interest for integration of foreign DNA and for mapping.

Inactivation of bovine herpesvirus 1 in semen using a hyperimmune egg yolk semen extender

Hyperimmune egg yolk semen extender was used for the inactivation of bovine herpesvirus (BHV-1) in experimentally infected bovine semen. As much as 5 x 10(4) TCID50/ml of virus was inactivated in semen as assayed by tissue culture. Moreover the hyperimmune egg yolk semen extender did not produce any adverse effect on the quality of the semen after being frozen/thawed in comparison with normal egg yolk semen extender (P > 0.05). The hyperimmune egg yolk semen extender is considered an important tool for containing the spread of BHV-1 from infected semen.

Analysis of cellular immune response in pigs recovered from porcine respiratory and reproductive syndrome infection

The cellular immune response to a European isolate of porcine reproductive and respiratory syndrome (PRRS) virus in animals recovered from the experimental infection has been studied in vitro. Peripheral blood mononuclear cells (PBMC) from these pigs proliferated specifically when they were stimulated with PRRS virus. This response was not detectable until 4 weeks after inoculation and remained for more than 3 months. Addition of blocking monoclonal antibodies to the cultures showed that this proliferation was mainly dependent on CD4(+) cells with the participation of SLA-class II molecules. T-cell cultures established by stimulating responding cells with PRRS virus and maintained in culture for up to 3 weeks showed an increase of CD8(+) CD4(+) and CD4(-) CD8(+) subsets within activated cells, gated according to their light scatter parameters, whereas CD4(+) CD8(-) cells declined along the time in culture. Within the activated cells, those expressing the TcR gammadelta receptor also increased, being most of them also positive for the CD8 marker. By RT-PCR, T-cells responding to the virus showed a Th1 type cytokine production pattern. During the culture period the cytotoxic activity against K-562 cells increased from 15 to 35% of specific lysis. This cellular immune response may play a relevant role in the clearance of PRRS virus and the recovery of the infection.

Conversion of US3-encoded protein kinase gene from pseudorabies virus in a diploid gene located within inverted repeats by genetic recombination between the viral genome isomers

The pseudorabies virus (PRV) genome consists of two components, long (U(L)) and short (U(S)) regions. The U(S) region is the only one capable of inverting itself relative to the U(L) region during productive infection, generating two equimolecular isomeric forms of viral DNA. Here we describe a recombinant virus (gIp2) generated by genetic recombination between pseudorabies viral isomers. This recombination event was observed in the parental virus gIS8, which was obtained by insertion of the alpha4-TK herpes simplex virus type 1 (HSV1) gene. The growth of gIS8 virus in the presence of 5-bromodeoxyuridine (BrdU) yielded gIp2. This was generated by nonhomologous recombination either between the two viral genomic isomers of gIS8, P and I(U/S), or between the same P isomer using nonhomologous and homologous recombination, with loss of the HSV1 sequences and duplication of the PRV US3-encoded protein kinase gene. Virus gIp2 is negative for TK, gI, gE, 11K and 28K and shows an in vitro replication capacity in neuronal cells approximately 22 times lower than that of parental virus gIS8, and similar to that of the Bartha vaccine virus strain in monkey kidney and human neuronal cells.

Expanded safety and immunogenicity of a bivalent, oral, attenuated cholera vaccine, CVD 103-HgR plus CVD 111, in United States military personnel stationed in Panama

To provide optimum protection against classical and El Tor biotypes of Vibrio cholerae O1, a single-dose, oral cholera vaccine was developed by combining two live, attenuated vaccine strains, CVD 103-HgR (classical, Inaba) and CVD 111 (El Tor, Ogawa). The vaccines were formulated in a double-chamber sachet; one chamber contained lyophilized bacteria, and the other contained buffer. A total of 170 partially-immune American soldiers stationed in Panama received one of the following five formulations: (a) CVD 103-HgR at 10(8) CFU plus CVD 111 at 10(7) CFU, (b) CVD 103-HgR at 10(8) CFU plus CVD 111 at 10(6) CFU, (c) CVD 103-HgR alone at 10(8) CFU, (d) CVD 111 alone at 10(7) CFU, or (e) inactivated Escherichia coli placebo. Among those who received CVD 111 at the high or low dose either alone or in combination with CVD 103-HgR, 8 of 103 had diarrhea, defined as three or more liquid stools. None of the 32 volunteers who received CVD 103-HgR alone or the 35 placebo recipients had diarrhea. CVD 111 was detected in the stools of 46% of the 103 volunteers who received it. About 65% of all persons who received CVD 103-HgR either alone or in combination had a fourfold rise in Inaba vibriocidal titers. The postvaccination geometric mean titers were comparable among groups, ranging from 450 to 550. Ogawa vibriocidal titers were about twice as high in persons who received CVD 111 as in those who received CVD 103-HgR alone (600 versus 300). The addition of CVD 111 improved the overall seroconversion rate and doubled the serum Ogawa vibriocidal titers, suggesting that the combination of an El Tor and a classical cholera strain is desirable. While CVD 111 was previously found to be well tolerated in semiimmune Peruvians, the adverse effects observed in this study indicate that this strain requires further attenuation before it can be safely used in nonimmune populations.

Preliminary study on genetic variability of Dicrocoelium dendriticum determined by random amplified polymorphic DNA

Genetic variability of adult specimens of Dicrocoelium dendriticum has been studied using random amplified polymorphic DNA (RAPD). The worms were collected from the infected livers of different sheep from several localities in León province (NW Spain). DNA fragments were amplified by means of decamer primer oligonucleotides of arbitrary sequence. Some primers produce complex and highly variable patterns of amplified DNA in D. dendriticum. Intra- and inter-population genetic variability of adult parasites were analyzed, scoring polymorphic and monomorphic reproducible bands by means of the Jaccard similarity, and dendrograms showing genetic relationships between individuals were obtained using the FITCH method. Genetic variability seems to be high in this parasite and genetic similarity within a population (worms infecting a single animal) is similar to the average similarity between worms from different sheep. These results suggest that each sheep is infected by numerous genetically different parasites from one or more populations of infected ants.

Evaluation of the effects of different trypsin treatments on semen quality after BHV-1 inactivation, and a comparison of the results before and after freezing, assessed by a computer image analyzer

Semen infected experimentally with infectious bovine rhinotracheitis virus (BHV-1) was treated with trypsin at concentrations of 0.30%, 0.25% and 0.15%, with or without (w or w/o) trypsin inhibitor in order to render the semen virus free. The trypsin treatments (at 0.30% and 0.25% by concentration) inactivating the virus up to 10(4) TCID50/ml, and its effects on semen quality were assessed weekly from the 1st to 20th week after being frozen. The following parameters were determined using a computerized semen analysis system (Hamilton Thorn motility analyzer, HTM): total motility, progressive motility and linearity of sperm cells. The results showed that the total and progressive motility of sperm cells were reduced in frozen/thawed semen, principally in the semen treated with trypsin at concentrations of 0.30%. Moreover, the plasma membranes were damaged by trypsin treatments (0.30% by concentration), as determined by the hypoosmotic swelling test (HOS test). These findings suggest that trypsin treatments were effective against the virus however the effects on semen quality and the possibility of a decrease in semen fertility were clear. Trypsin treatment could be recommended at a maximum concentration of 0.25% (w/o trypsin inhibitor) on semen with a high concentration and high motility values of spermatozoa before freezing.

Determination of metal ions in algal solution samples by capillary electrophoresis

Trace metals determination in aqueous samples can be readily accomplished by capillary electrophoresis (CE) via indirect absorbance detection. A method for the separation of metal ions is presented and applied to the determination of seven metals in algal solution samples. 2-Hydroxyisobutyric acid background electrolyte (BGE) containing UV CAT-1 (an ultraviolet-absorbing amine) is used to perform capillary ion analysis. Acetic acid is used to adjust the pH value of BGE to 4.4. All ions can be separated in less than 15 min. All peaks are well separated and baseline resolved (i.e., no peaks overlapped). This work presents the applicability of CE to the quantitative analysis of algal solution samples and shows the adsorption process of seven metals in solution (Mn, Cd, Cr, Ni, Zn, Pb, Cu) to Chlorella vulgaris. The innovation of the application of CE in the determination of metals bound by Chlorella vulgaris is shown to be an improvement of the pH over what has been published previously. The detection limit is in the range of 13 (Mn) to 102 (Pb) ppb with electrokinetic injection mode (15 kV, 7 s). Reproducibility was 1.4% for the migration time, better than 5% for peak area for four of the metal ions (Cr, Mn, Cd, and Cu), and lower than 5% for the other three (Ni, Zn, and Pb). Calibration curves are linear for most ions in the 10(-7)-10(-5)M range (correlation coefficient r2 = 0.9933-0.9986) using electrokinetic injection mode.

Home care referral after emergency department discharge

OBJECTIVE

The purpose of this study was to assess the need for home health care referral screening for elderly patients after ED discharge. The specific research question addressed was: Is there a need for home care referral screenings for elderly patients discharged from the emergency department?

DESIGN

A nonexperimental, retrospective, descriptive design was used in this project.

METHODS

A convenience sample of 194 closed medical records was obtained from a Midwestern hospital emergency department. The medical records were from patients 65 years of age and older who had visited the emergency department during a 3-month period. One chart audit tool was completed for each medical record.

RESULTS

Eighty-eight (45.4%) of the 194 patients in the study could have benefited from a home care referral.

CONCLUSION

Elderly patients frequently access the health care delivery system through the emergency department, but little is known about the outcomes of such usage, particularly in the context of continuity of care. If home care referral screenings of elderly ED patients are performed and appropriate referrals are made before ED discharge, a seamless delivery system of health care is provided. A home care visit resulting from a referral may be all that is needed for the maintenance of a patient's condition. To improve the quality and continuity of patient care, home care screening should be integrated into the routine discharge ED activities.

Transplacental infection following exposure of gilts to porcine reproductive and respiratory syndrome virus at the onset of gestation

Twenty-five gilts without measurable porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) serum antibody titres were used for this experiment. All of them were randomly assigned to one of the treatment groups at the time of artificial insemination. Twelve gilts were exposed to PRRSV, of these, six were slaughtered on day 10 after exposure and constituted group A. The remaining six were slaughtered on day 20 after infection and constituted group C. Thirteen gilts were used as controls, six of these were slaughtered on day 10 after treatment and constituted group B. The remaining seven were slaughtered on day 20 after treatment and constituted group D. The infected gilts were inoculated with PRRSV intranasally and intravenously in the ear vein. They were observed for clinical signs of infection and the effects on conception and fertilization rates were studied, while the gilts and their embryos were tested for PRRSV and homologous antibodies. The infected animals developed signs of PRRS associated with anorexia and slight pyrexia. Infection was verified by reisolation of the virus from serum and other tissue samples and also by seroconversion. Ten out of 12 infected gilts and 10 out of 13 controls were pregnant at the time of slaughter and the ratio of embryos to corpora lutea was the same in both, infected and control groups (0.75). Therefore, infection with PRRSV at the onset of gestation did not appear to interfere with conception and fertilization rates and subsequent pregnancy. The PRRSV was not isolated from any of the embryos collected at day 10 postexposure, but was present in 20-day-old embryos of group C gilts. In this group, 60% of litters were infected prenatally, with 16% of embryos infected. The proportion of dead embryos was three times greater than in a control group D (35.4% and 9.8%, respectively). The results of this report indicate that exposure of susceptible gilts to PRRSV at the onset of gestation has no significant effect on conception and fertilization rates. However, although infection does not appear to have any effect on the embryos before implantation, it can result in transplacental infection and embryo death.

[Association of alpha and beta thalassemia with alpha gene triplication in one family]

We describe the haematological data and molecular results of a native family from Cádiz in that one is produced the a within heterozygous beta 0 thalassaemia (IVS-1, nt 1-G-->A), heterozygous alpha+ thalassaemia (-alpha 3.7) and alpha gene triplication (alpha alpha alpha 3.7). PATIENTS AND METHODS) We are studied 7 members to a family composed by father (I1), mother (I2) and five children (II1, II2, II3, II4, II5). The molecular biology study of the alpha gene was realized by Southern blot method using the restriction enzymes Bam HI, Bgl II and Eco RI and hybridized with alpha probe of the plasmid PRB 1 (fragment of 1.5 Kb digested with the enzyme Pst I). The genes were studied by the technique of the polymerase chain reaction (PCR), modified according to designated method "Amplification Refractory Mutation System" (ARMS).

RESULTS

The father (I1) presents an interaction of therozygous beta 0 thalassaemia with heterozygous alpha + thalassaemia (beta 0/beta 1;alpha alpha/-alpha 3). The mother (I2) shows an alpha gene triplication (beta A/beta A: alpha alpha alpha 3.7/alpha alpha). Finally the children are expressed 5 possibilities: II4 he is normal (beta A/beta A; alpha alpha/alpha alpha), II2 he has alpha gene triplication (beta A/beta A; alpha alpha/alpha alpha alpha 3.7), II3 he has heterozygous beta 0 thalassaemia (beta 0/beta A; alpha alpha/alpha alpha), II5 he has interaction between heterozygous beta 0 thalassaemia and heterozygous alpha gene triplication (beta 0/beta A; alpha alpha alpha 3.7/alpha alpha) and II1 presents an interaction between a heterozygous beta 0 thalassaemia and together with the lost of one alpha gene in one chromosome he also presents a alpha gene triplication in other one (beta o/beta A; alpha alpha/alpha alpha). The hematological data of II5 corresponds to a intermediate thalassemia with not transfusion dependent feature an opposite to II1 that presents a heterozygous thalassemic trait features with 4 alpha genes.

DISCUSSION

The phenotypical expression of the different interactions of these mutations in this family, points out, the relevant role that the unbalance globins chains plays in the pathogenesis and development of the clinical manifestations of the patients with the thalassaemia syndromes.

Insemination of susceptible and preimmunized gilts with boar semen containing porcine reproductive and respiratory syndrome virus

Twenty-one gilts without measurable PRRSV serum antibody titres were identified for this experiment. Seven gilts were used as controls (Group C) and 14 as principals. Of these, 7 gilts were preimmunized to PRRSV and constituted Group B, while 7 gilts remained seronegative and constituted Group A. The principal gilts were inseminated with boar semen containing PRRSV and were killed 20 d later. The control gilts were treated similarly but were not exposed to PRRSV. Gilts were observed for clinical signs of infection. The effects on the conception rates were studied and gilts and embryos were tested for PRRSV and homologous antibodies. Group A and B gilts developed signs of PRRS associated with anorexia and slightly elevated body temperatures. Transmission of the infection was demonstrated by the isolation of PRRSV from serum and other tissue samples of principal gilts and also by seroconversion. The results show that early infection may have an insignificant effect or no effect on the conception and fertilization rates. However, exposure to PRRSV at the time of insemination can result in transplacental infection of embryos. In Group A gilts, 5 of 6 litters were infected prenatally with 7.6% of embryos infected. In Group B gilts, 1 of 5 litters and 1.3% of embryos were infected. Moreover, approximately 2 and 4 times more embryos were dead in litters of gilts from Group A and Group B than in gilts from control Group C. The isolation of PRRSV in 3 dead embryos suggests that the embryos may have died as a result of the direct effect of the virus. It can be concluded that the insemination of either seronegative or preimmunized gilts with boar semen containing PRRS V may have an insignificant effect or no effect on conception and fertilization rates, although it can result in transmission of the virus and embryonic infection and death.

Effect of porcine reproductive and respiratory syndrome virus (PRRSV) on development of porcine fertilizedova in vitro

Fertilized pig ova, collected from 14 estrus-synchronized gilts 32 h after presumed ovulation were microinjected or cultured for 72 h in Beltsville Embryo Culture Medium-3 with or without Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). To detect virus in the samples, virus isolation of swine alveolar macrophage, Reverse Transcriptase Polymerase Chain Reaction and Fluorescent Antibody techniques were employed. Microinjection or incubation of embryos with PRRSV did not significantly inhibit development of the porcine embryos in vitro when compared with that of controls (P = 0.75 and P = 0.14, respectively). Although either 10 to 20 TCID50 were microinjected or large concentrations of virus were used for embryo exposure by incubation, PRRSV was not detected in association with the embryos. It is concluded based on the experiments reported here that 4- to 16-cell stage pig embryos are not susceptible to productive infection with PRRSV in vitro.

Localization of prothymosin alpha in the nucleus

Prothymosin alpha is a widely distributed acidic protein to which an immunological function that involved its secretion was initially assigned. However, recent experiments suggest that it is a nuclear protein related to cell proliferation. To study the subcellular distribution of prothymosin alpha we have used a polyclonal antibody raised against its C-terminus. Using indirect immunofluorescence prothymosin alpha was located in the nucleus of HeLa, L929, IT-45R1, and NIH3T3 cells, mouse thymocytes, and human thymic stromal cells. The levels of prothymosin alpha mRNA were increased when the proliferation of IT-45R1 cells was induced, as has been described by others in thymocytes and NIH3T3 cells. These results show that prothymosin alpha is a nuclear protein related to cell proliferation.

Phylogenetic relationships of european strains of porcine reproductive and respiratory syndrome virus (PRRSV) inferred from DNA sequences of putative ORF-5 and ORF-7 genes

The complete ORF-5 gene and a fragment of the ORF-7 gene from 14 different European porcine reproductive and respiratory syndrome virus (PRRSV) isolates were amplified by reverse transcriptase polymerase chain reaction (RT-PCR), and their nucleotide sequences were determined. The ORF-7 gene displayed nucleotide and amino acid identities of 94.1-99.6% and 95.3-100% among isolates from different countries. The ORF-5 gene showed higher nucleotide (87.1-99.2% identity) and amino acid (-88% identity) variability. The resulting sequences were aligned with other European and North American PRRSV strains and phylogenetic relationships among these strains were established by the maximum parsimony method. The phylogenetic trees inferred from both genes were in agreement and showed that European and North American PRRSV strains clearly represent two different genotypes. According to both trees, there is a perfect correlation between strains and the countries in which they were isolated. Additionally, the phylogenetic position of European and North American PRRSV strains within the recently proposed family Arteriviridae was also analyzed.

Exposure of gilts in early gestation to porcine reproductive and respiratory syndrome virus

Twenty-five gilts without measurable serum antibody titres to porcine reproductive and respiratory syndrome virus (PRRSV) were identified and 16 were inoculated with PRRSV at seven, 14 or 21 days of gestation and killed 20 to 22 days later to determine the effect of the virus on their embryos. The remaining nine gilts were not exposed to PRRSV, but were killed at the same stages of gestation. The gilts were observed for clinical signs of infection and the gilts and their embryos were tested for PRRSV and homologous antibodies. The infection was demonstrated by the re-isolation of the virus and its detection by the reverse transcriptase polymerase chain reaction in serum and other tissue samples from the inoculated gilts, and also by seroconversion. However, the gilts remained healthy throughout the study, except for one which was depressed and anorexic for two days. Two of the litters from the gilts challenged with PRRSV on day 14 of gestation contained one and three infected live embryos; the other embryos from these two litters did not contain detectable virus, although most of the embryos in one of the litters were dead. The other nine litters from the gilts challenged with PRRSV and the control litters, showed no evidence of infection.

Value of MR findings in predicting the nature of the soft tissue lesions: benign, malignant or undetermined lesion?

OBJECTIVE

To evaluate the value of each MRI findings in differentiating the nature of soft tissue lesions.

SUBJECTS AND METHODS

We performed a blind retrospective review of MR imaging in 65 consecutive soft-tissue lesions (cystic lesions in or around the joints, and the soft tissue abnormalities directly related to a known trauma were excluded). Morphology and signal intensity characteristics were analyzed. Each lesion was considered as benign tumor malignant tumor, benign but locally aggressive lesion, and undetermined. The final diagnosis was established pathologically (n = 45), and by the association of other imaging studies, clinical findings and follow-up over 2 yr (n = 20).

RESULTS

Involvement of one compartment was equal in malignant (57.1%) and benign (56.2%) tumors, whereas multicompartmental involvement was most common in non-tumoral lesions (39.1%) (P < 0.05). Well-defined margins were most frequent in benign tumors (189.2%) (P < 0.05). The change from homogeneous to heterogeneous pattern on T1- and T2-weighted sequences as a predictor of malignancy showed a sensitivity of 77.7% and a specificity of 20%. Based on the MRI findings a diagnosis of benign lesion was established with a sensitivity of 60.7% and a specificity of 77.7%; malignant tumor with a sensitivity of 78.5% and a specificity of 96% and benign locally aggressive lesions with 54.5% and 88.1%, respectively. With the addition of the clinical data, an etiologic diagnosis was performed in 78.5% benign tumors, in 85.7% malignant tumors, and in 95.6% benign non-tumoral lesions. Undetermined lesion was diagnosed in eight masses.

CONCLUSION

Soft tissue lesions can be diagnosed with certainty in many benign tumors based on the integrated evaluation of morphology and signal intensity MR findings. The association of MR and clinical data allowed us to identify benign but locally aggressive lesions, mostly related to infection. MR findings are highly specific for malignant tumor, although a histologic diagnosis cannot be performed based only on image analysis. When a mass is undetermined and no criteria for benignity or malignancy can be established, pathologic analysis should be always performed.

Open reading frame 5 of porcine reproductive and respiratory syndrome virus as a cause of virus-induced apoptosis

The gene product of open reading frame 5 (p25) of porcine reproductive and respiratory syndrome (PRRS) virus has been expressed by coinfection of culture cells with vaccinia virus expressing the T7 RNA polymerase and a recombinant vaccinia virus encoding the open reading frame 5 gene under the T7 promoter and the encephalomyocarditis virus internal ribosome entry site. In spite of the reported efficiency of the expression system, very poor accumulation of p25 protein was observed and a strong cytotoxicity was produced in the doubly infected cells. This cell toxicity was shown to occur by induction of apoptosis, as indicated by nucleosome ladder formation, chromatin condensation, and rRNA degradation. Apoptosis induction was also observed after infection of cultured cells with an adapted PRRS virus strain and after infection of swine macrophage cells with a PRRS virus field strain. Contrary to the observations made for other cases of virus-induced apoptosis, we could not prevent p25 protein-induced apoptosis by using a cell line permanently expressing Bcl-2 protein.

Cloning and characterization of an IS-like element present in the genome of Brevibacterium lactofermentum ATCC 13869

A repetitive DNA element of the Gram+ Brevibacterium lactofermentum (Bl), cloned by a modification of the subtractive hybridization method, contained a 1.4-kb IS-like element, IS13869, which included an open reading frame (ORF) inside a perfect 26-bp terminal inverted repeat (TIR). An 8-bp direct repeat (DR) was found outside each TIR. The ORF encoded a deduced protein of 436 amino acids (49 380 Da) with extensive similarity to other known transposases of insertion elements of Mycobacterium smegmatis (IS1096). Pseudomonas sp. (tpnA) and Corynebacterium glutamicum (IS31831). Distinct patterns were observed in different strains of Bl by hybridization with a probe internal to IS13869: four copies of IS13869 occurred in the wild type (wt) and R31 strains, but only three of them were observed in a recA derivative of the wt. Analysis by pulsed-field gel electrophoresis suggested that at least one copy of IS13869 had changed its position inside the chromosome during the lineage of a Bl derivative.

Rapid and high sensitivity test for direct detection of bovine herpesvirus-1 genome in clinical samples

A procedure for direct detection of the BHV-1 genome in clinical samples, including semen, was developed. The method is based on the PCR amplification of a highly conserved DNA fragment within the glycoprotein gI sequence of the virus (323 bp between nt 1491 to nt 1814). The method is rapid and highly specific for all 27 subtypes assayed, which are included in the clinical and genetically different groups of BHV-1. The viral origin of the PCR product was assessed by Southern hybridization, with an internal probe. The method for DNA isolation from clinical samples included a fast extraction procedure with Chelex 100 resin allowing the loading of larger amounts of DNA in the PCR and in turn increasing the sensitivity of the method of detection. The level of sensitivity achieved by PCR was in the range of 1 TCID(50). This PCR assay may be an useful tool for BHV-1 monitoring in semen banks at low cost.

Semen changes in boars after experimental infection with porcine reproductive and respiratory syndrome (PRRS) virus

Eleven boars seronegative to porcine reproductive and respiratory syndrome virus (PRRSV) were trained for semen collection: five boars were inoculated intranasally with 6 x 10(6)TCID(50)/ml of PRRSV (Group A); four boars were inoculated intranasally with 6 x 10(4)TCID(50)/ml (Group B); and two boars were used as uninfected control (Group C). Semen samples were collected at 7-d intervals from 49 d prior to experimental inoculation with PRRSV to 70 d after inoculation, and were examined for sperm volume, sperm concentration, sperm morphology, sperm motility and for the presence of PRRSV. The infection in boars was demonstrated by the reisolation of PRRSV from the serum of all inoculated boars. Rectal temperatures and general health of the boars were clinically normal throughout the trial. Differences were observed in the quality of semen collected from boars after experimental infection with PRRSV. This infection induced a significant decrease in sperm motility and in spermatozoa with normal acrosomes. Of the semen samples tested for virus isolation in swine alveolar macrophages PRRSV was only isolated in 1 boar from Group B. The virus was detected in an additional semen sample in Group A by the production of an antibody titer in a biological assay. All attempts to detect PRRSV by RT-PCR in semen samples were unsuccessful. Nevertheless, from our study it is possible to suggest that the PRRSV can occasionally be transmitted in the semen during the initial phase of the disease.

Rapid and sensitive detection of the bovine viral diarrhea virus genome in semen

A reverse transcription-polymerase chain reaction (RT-PCR) procedure was developed for the detection of bovine viral diarrhea virus (BVDV) in cell culture supernatant and in bovine semen. Several sets of primers, PCR conditions and extraction methods were examined to optimize the procedure. A set of primers designed to amplify a highly conserved portion of the p80 gene from BVDV (corresponding to NADL strain sequence from bp 6668 to 7107), was demonstrated to be the most effective. These oligonucleotide primers consistently amplify a 440-bp fragment from several non-cytopathic and cytopathic biotypes of BVDV. The viral origin of the PCR products was assessed by sequencing. The introduction of a Sephacryl S-400 chromatography step to remove seminal inhibitors prior to RNA extraction permitted RT-PCR detection of BVDV in raw and extended semen samples. A maximum sensitivity of 0.4 TCID50 was achieved with this method using RNA extracted from tissue supernatants. This RT-PCR assay may be a useful tool for the detection of BVDV in semen of persistently infected bulls.

[Pheochromocytoma]

The authors present the case of a 51 year old woman with severe arterial hypertension with parixisms, without medical control. The clinical, laboratory and imagiological investigation showed a pheochromocytoma at the right adrenal gland. The patient was submitted to surgery with success. Specific aspects of differential diagnosis are discussed and a review of the more relevant features of clinical diagnosis, pre-operative preparation and surgical technique are presented.

Biochemical traits and antimicrobial susceptibility of Streptococcus suis isolated from slaughtered pigs

A total of 522 Streptococcus suis isolates were recovered from the tonsils of slaughtered pigs by culturing on media containing different specific antisera. The serogroup reactions were determined by coagglutination. The most frequently isolated serotype was serotype 4 (representing 28.7% of the isolates), followed by serotype 3 (24.9%) and serotype 2 (22.6%). Typable isolates were examined by growth in 6.5% NaCl, amylase activity, acetoin production, susceptibility to optochin and production of acid from mannitol, melibiose, raffinose, salicin, sorbitol and trehalose. Finally, all isolates were tested for antimicrobial susceptibility against ampicillin, cephalotin, lincomycin, neomycin, penicillin, spiramycin and trimethoprim-sulphamethoxazole using the disk-diffusion technique. All isolates were amylase-positive and acetoin-negative, and failed to grow in 6.5% NaCl broth. Nine isolates were optochin-susceptible. Moreover, 10 isolates produced acid from mannitol, 21 produced acid from sorbitol, and 36 and 37 did not produce acid from salicin and trehalose, respectively. Six salicin- and trehalose-negative isolates and two mannitol- and sorbitol-fermenting isolates were found. Biochemical differences between serotypes were not observed. The most active drugs against S. suis were the beta-lactam antibiotics, although only 83.3%, 70% and 78.5% of isolates were susceptible to ampicillin, cephalotin and penicillin, respectively. Half of the isolates were resistant to trimethoprim-sulphamethoxazole, and resistance to lincomycin, neomycin and spiramycin appeared to be very high.

Pulsed-field gel electrophoresis analysis of the genome of amino acid producing corynebacteria: chromosome sizes and diversity of restriction patterns

A large number of species of corynebacteria are known to be amino acid producers, including members of the genera Corynebacterium and Brevibacterium. Pulsed-field gel electrophoresis (PFGE) of DNA fragments obtained by using endonucleases which recognize AT-rich hexanucleotide or octanucleotide sequences produces a discrete pattern of bands useful for fingerprinting and physical mapping of the chromosome. Using Pacl and Swal endonucleases the genome of Brevibacterium lactofermentum ATCC 13869 (genome size 3052 kb) was consistently cut into 26 and 20 bands, respectively, and the genome of Corynebacterium glutamicum ATCC 13032 (2987 kb) yielded 27 and 26 fragments, respectively. The pattern of restriction fragments was identical for related strains (B. lactofermentum ATCC 13869, B. lactofermentum BLO, B. lactofermentum R31) but different from the pattern of fragments of other soil isolates of the same species (B. lactofermentum DSM 20412) or from closely related organisms such as C. glutamicum; the different pattern of restriction fragments may be used to differentiate taxonomically related species. Brevibacterium linens showed a different behaviour, due to its high G+C content; its genome (3105 kb) was resolved into 8 or 15 fragments, respectively, by digestion with the hexanucleotide-recognizing endonucleases DraI and AseI. PFGE of DNA fragments obtained using these enzymes is a powerful technique for quick resolution of the corynebacteria genome into a small number of large fragments.

Radionuclide studies in patients with stress-induced ST-segment elevation after acute myocardial infarction

The meaning of a stress-induced ST-segment elevation (delta ST) after acute myocardial infarction is still controversial. Some studies show it is related to asynergy, and other studies show it is related to ischemia. However, no study has compared the delta ST with both stress-induced ischemia and stress-induced asynergy in the same group of patients. With this purpose, 88 patients were studied 16 +/- 4 days after acute myocardial infarction. They were submitted to a dobutamine stress test on two different occasions 1 to 2 days apart. Dobutamine was infused up to 40 micrograms/kg/min with blood pressure and electrocardiographic controls. Thallium-201 single-photon emission computed tomography was performed during the highest dobutamine dose and 3 to 4 hours later. Equilibrium radionuclide ventriculography was performed at rest and during the highest dobutamine dose. Global and regional (hypokinetic area) ejection fractions were quantified. The ST segment was elevated > or = 1 mm in 33 patients at rest and in 71 during stress. A stress-induced delta ST was seen in 66 patients. Redistribution was detected in 65 patients. Multiple regression analysis showed a significant correlation between ST elevation and thallium defect score both at rest and during stress. No correlation was found between delta ST and redistribution score. However, a significant inverse linear correlation was found between the delta ST and the change in regional ejection fraction: the greater the delta ST, the smaller the change in regional ejection fraction with dobutamine. In conclusion, a stress-induced delta ST is not related to ischemia but to stress-induced left ventricular asynergy.

Direct detection of the porcine reproductive and respiratory syndrome (PRRS) virus by reverse polymerase chain reaction (RT-PCR)

A method for direct detection of the porcine reproductive and respiratory syndrome (PRRS) virus was developed, based on reverse transcription of the viral RNA coupled to DNA amplification by polymerase chain reaction. A set of primers was designed from Lelystad virus sequence within ORF 7 encoding nucleocapsid protein. From seven Spanish field isolated strains the 312 bp amplified fragment was cloned and sequenced. Alignment with Lelystad virus sequence revealed a 96-97% homology. A maximum sensitivity of 6.7 TCID50 was achieved with the reported procedure in experimentally infected swine alveolar macrophages cultures. The sensitivity obtained in crude clinical samples from experimentally infected 3-weeks old pigs was approximately 10(2) TCID50. High specificity for the PRRS virus was demonstrated for the method, as none of the seven common swine virus assayed rendered DNA amplification product.