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.