Evaluation of European Society of Cardiology (ESC) 0/1-hour algorithm in the diagnosis of 90-day major adverse cardiovascular events: a multicenter United States cohort study

Background

The ESC 0/1-hour algorithm using high sensitivity troponin (ESC 0/1-h) is a rapid triage protocol for diagnosing acute coronary syndrome, however the classification performance of the algorithm in the US population is uncertain. Further, evidence for the use of ESC 0/1-h in the long-term diagnosis of major adverse cardiovascular events (MACE) remains limited.

Purpose

To evaluate the performance of the ESC 0/1-h algorithm in diagnosing 90-day MACE in a diverse US cohort.

Methods

In this prospective, multicenter, observational cohort study, adult emergency department patients who were evaluated for suspected ACS were enrolled at eight sites in the US. Serial 1-hour blood samples were collected and high sensitivity troponin T (hs-cTnT) concentrations were measured in a central laboratory using the hs-cTnT assay. Primary outcome included major adverse cardiovascular events (MACE) within 90 (+30) days of enrollment. MACE defined as myocardial infarction (MI), cardiovascular or uncertain death, and coronary revascularization. Presence of MI and cardiovascular death were adjudicated by independent reviewers blinded to hs-cTnT results. Each participant was stratified to one of three risk groups as determined by ESC 0/1-h algorithm. Diagnostic classification performance metrics with exact confidence intervals (i.e. negative predictive value [NPV], positive predicted value [PPV], sensitivity, and specificity) were evaluated for each risk group where appropriate.

Results

Among 1430 eligible participants, 45.8% (655/1430) were women and 36.6% (524/1430) were African American with a mean age of 57.6±12.8 years. MACE at 90-days occurred in 15.5% (221/1430). ESC 0/1-h stratified 59.5% (851/1430) subjects in Rule-Out range and 13.0% (186/1430) subjects in Rule-In range. The Rule-Out criteria had an NPV and sensitivity for 90-day MACE of 96.8% (95% CI: 95.4–97.9%) and 87.8% (95% CI: 82.7–91.8%), respectively. For 90-day cardiovascular death or MI, Rule-Out criteria had an NPV of 98.2% (95% CI: 97.1–99.0%) and sensitivity was 92.4% (95% CI: 87.8–95.7%). The Rule-In criteria had a PPV of 60.8% (95% CI: 53.3–67.8%) for both outcomes. Rule-In criteria had a specificity for 90-day MACE and 90-day cardiovascular death or MI of 94.0% (95% CI: 92.5–95.2%) and 94.1% (95% CI: 92.6–95.3%), respectively. Among the 27.5% (393/1430) participants classified in neither risk groups, the prevalence of 90-day MACE was 20.6% (81/393) and the prevalence of 90-day cardiovascular death or MI was 17.8% (70/393)

Conclusion

In a prospective, multicenter, US cohort, the ESC 0/1-h algorithm was unable to achieve a sufficiently high NPV to safely exclude the diagnosis of MACE within 90 days after emergency department presentation. New hs-cTn algorithms specific to the US population may be warranted.

ESC 0/1-h 90 Day Outcomes

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics

Metabolic responses of running shod and barefoot in mid-forefoot runners

BACKGROUND

The purposes of this study were to compare the oxygen cost, metabolic parameters and temporalspatial variables between barefoot and shod running in trained mid-forefoot runners.

METHODS

Experienced runners (N.=21; 30±10.9 years; 16 men) performed two separate 20 minute treadmill running bouts at ~77% of estimated maximal heart rate. Rate of oxygen consumption (VO2), energy cost, fuel use and heart rate (HR) were collected continuously using a portable gas analyzer. Three-dimensional motion capture was used to measure temporalspatial parameters.

RESULTS

Participants ran at a mean self-selected speed of 3.1±0.3 m/s for both conditions, at intensities corresponding to mean HR values of 146 bpm (shod) and 144 bpm (barefoot). Steady State VO2 was not different between the shod and barefoot conditions (39.4± 4.7 mL/kg*min vs. 40±5.2 mL/kg*min, respectively). The total energy expended in the shod and barefoot conditions was 974±134 kJ and 979±142 kJ. The average non-protein respiratory exchange ratios, proportions and amount of fat and carbohydrate used were not different between conditions. Cadence was 2.5% higher and center of gravity vertical displacement was 0.5 cm less for the barefoot condition (P<0.05).

CONCLUSION

In trained mid-forefoot runners experienced with barefoot running, there are not significant metabolic differences between shod and barefoot running conditions. Barefoot running increases cadence and decreases foot contact time and vertical displacement. Experienced participants were likely able to titrate kinematics to standardize energy output and fuel use for a given running distance and speed irrespective of shoe wear.

Outpatient rehabilitation outcomes in obese patients with orthopedic conditions

BACKGROUND

Obesity is related to the development of functional and mobility impairment, musculoskeletal pain and orthopedic problems. Irrespective of age, obese children and adults have impaired walking capacity and body transfer ability, and difficulties navigating obstacle courses or community spaces. Obesity is related to relative strength deficits, musculoskeletal pain, kinesiophobia, low self-efficacy and a decline in quality of life.

AIM

This review provides an update of the available evidence for the efficacy of outpatient rehabilitation programs for the treatment of disabling obesity.

RESULTS

Outpatient rehabilitation programs can effectively improve muscle strength, self-confidence and physical function. Key rehabilitation components should include aerobic exercise (AX), resistance exercise (RX) and cognitive strategies to cope with the unique challenges posed by obesity. Available high quality evidence indicates that 3-18 month rehabilitation programs that included aerobic and strengthening exercise (2-3 days per week) with caloric restriction (typically 500-750 kcal deficit/ day), elicited the best changes in functional performance measures compared with exercise or diet alone.

CONCLUSION

Comprehensive outpatient rehabilitation interventions coupled with diet can catalyze lifestyle patterns that improve and preserve physical function over the life span.

Scaling up collaborative TB-HIV activities in Latin America

TB-HIV collaborative activities are one of the cornerstones of TB control in the Stop TB strategy. Since 2003, most countries in Latin America and the Caribbean have been gradually implementing TB-HIV collaborative activities; however, limited information is currently available on the degree of implementation. This study is therefore aimed at describing to what degree TB-HIV collaborative activities are being implemented in 17 countries selected for the study. These countries were asked to complete a semi-structured questionnaire. An analysis of this questionnaire revealed that the challenges for TB-HIV collaboration lie in the fields of human resources, surveillance and HIV testing of TB patients.

Le travail musculaire excentrique : intérêts dans la prise en charge thérapeutique du sportif

OBJECTIVES

To review the research on the effects and indications of eccentric muscular contraction in the athlete.

METHODS

We searched the Medline database using the key words eccentric and negative work for reports of eccentric muscular contraction published from 1993 to 2004.

RESULTS

The physiologic features of eccentric contraction remain unknown but significantly differ from concentric contraction. Eccentric contraction has a specific effect: during sports practice, it permits the muscular and tendinous complex to support strain and strengthens the muscular action of articular stabilization. But eccentric contraction produces injuries: delayed-onset muscle soreness, and muscle rupture and tendinous injuries such as luxation, rupture, and tendinitis.

CONCLUSION

Treatment and prevention must have controlled protocols. In therapy, eccentric contraction must be realized at progressive speeds and resistances. Prevention of tendinous injury necessitates quantifying eccentric activity during training.

[Pancoast syndrome and endobronchial tumor infiltration as the first manifestation of Hodgkin lymphoma]

The most common cause of Pancoast syndrome is bronchogenic carcinoma. Other less common causes are solid tumor metastases, other chest tumors, infections, and hematologic neoplasms. Pancoast syndrome due to lymphoma is very rare, and cases described in the literature are essentially associated with non-Hodgkin lymphomas. In a review of the literature we found a single case of Pancoast syndrome secondary to a Hodgkin lymphoma; however, the syndrome manifested during recurrence of disease in that patient. We report a case of nodular sclerosis Hodgkin lymphoma which first manifested clinically as Pancoast syndrome and which was initially diagnosed by bronchial biopsy.

[Lung cancer in the health care area of A Coruña (Spain): incidence, clinical approach and survival]

OBJECTIVE

To determine the incidence, clinical approach, diagnostic delay and survival for bronchogenic carcinoma (BC) in the public health area of A Coruña (Spain).

PATIENTS AND METHOD

This was a retrospective study of patients with a diagnosis of BC made in 1995 and 1996 in a health care area with 509,000 inhabitants. For analysis we gathered demographic, clinical and cyto-histologic data and analyzed diagnostic delay, extension of disease and time of death. Crude, age-specific and age-standardized incidences were calculated.

RESULTS

BC was diagnosed in 378 patients (95% men and 5% women). The crude incidence was 37 per 100,000 inhabitants (73.7 per 100,000 men and 3 per 100,000 women) and the age-standardized incidence was 21.7 per 100,000. Diagnosis was by cyto-histology in 87% of the cases, and the most frequent biopsy finding was epidermoid carcinoma. Diagnosis was by clinical or radiologic findings for 13.7%, and patients in that group were older and had greater comorbidity. No symptoms were present in 13% and in those patients diagnosis was earlier, with non-small BC predominating and 60% treated surgically. The diagnostic delay (time from the first symptom to histologic confirmation) was 2.5 months (median, 2.1), and length of delay did not affect survival. Surgery was performed in 23% of the patients with non-small BC. The median survival was 7.1 months (5.2 months for patients who were not treated surgically, and 37.6 for those who were).

CONCLUSIONS

The incidence of BC in men in our study is consistent with that reported for other Spanish regions, although the incidence we observed for women is much lower. Diagnostic delay did not affect survival. The percentage of patients with surgical-stage disease is very low and survival is very short. These findings support the need for early diagnosis.

trans-Resveratrol and grape disease resistance. A dynamical study by high-resolution laser-based techniques

Two modern laser-based techniques were synchronously applied to study the dynamics of the trans-resveratrol activity in Botrytis cinerea-infected grapes. Direct analysis of trans-resveratrol in both infected and noninfected grapes (Vitis vinifera, Aledo variety) was performed by using an analytical technique incorporating laser desorption coupled with laser resonant ionization and time-of-flight mass spectrometry. On the other hand, one of the most sensitive on-line methods for trace gas detection, laser photoacoustic spectroscopy, was used to investigate the involvement of the plant hormone ethylene (C(2)H(4)) in the B. cinerea grapes interaction and its temporal relationship with the trans-resveratrol content upon infection. The trans-resveratrol content and the ethylene released by noninfected grapes showed an opposite behavior. In this case, a high trans-resveratrol content corresponds to a low ethylene emission. For the B. cinerea-infected grapes, ethylene emission rises up after 48 h when the analogous content of trans-resveratrol started to decrease irreversibly. Moreover, the activity of trans-resveratrol as natural pesticide has been investigated by exogenous application on grapes. A short submerge (5 s) of the grapes in 1.6 x 10(-4) M solution of trans-resveratrol delays the increase of C(2)H(4) emission with about 48 h and produces a decrease of the C(2)H(4) concentration and its emission rate. The treatment has positive effects on fruit conservation during storage; it doubled the normal shelf-life of grapes at room temperature, maintaining their post-harvest quality within 10 d.

Improving postharvest resistance in fruits by external application of trans-resveratrol

As it is well-known, one of the main problems of modern agriculture is the postharvest fruit losses due to pathogen's attack and natural senescence during storage. Well established solutions to improve this situation, such as, for example, storage under controlled conditions and the use of synthetic pesticides, are not free of problems due to human health risks and environmental effects caused by chemical pesticides. A new strategy to solve these problems consists of developing methods to improve the natural plant resistance by using, upon their identification, the plant's own defense molecules, in other words, applying methods based on the plant's own natural processes of pest suppression to control spoilage. This requires the identification of components of the natural defense response in plants, which, in turn, demands highly sensitive, fast, and versatile analytical methods especially for trace, nonvolatile, compounds. In this work a laser-based technique has been applied for screening the postharvest elicitation of resveratrol by Botrytis cinerea in grapes. Besides antifungal character, resveratrol is known to present important antioxidant properties, which could also have positive effects on fruit conservation during storage. Consequently, several experiments were carried out in which exogenous application of resveratrol to several fruits maintained their postharvest quality. The quality of both resveratrol-treated and untreated fruits has been studied by the assessment of the biochemical composition and sensory analysis. Indeed, the present work demonstrates that the external application of resveratrol does not alter the sensorial and biochemical properties of the fruit.

Analysis of trans-resveratrol by laser desorption coupled with resonant ionization spectrometry. Application to trans-resveratrol content in vine leaves and grape skin

A method has been developed for nonvolatile compound analysis in fruits, namely, trans-resveratrol in grapes and vine leaves. This has been accomplished by the combination of laser desorption with resonance-enhanced multiphoton ionization coupled to time-of-flight mass spectrometry detection. After the optimization of the experimental conditions and the finding of the resonant wave-length of the substance, the full validation of the technique (i.e., linearity, repeatability, reproducibility, accuracy, detection limit, and quantification limit) was carried out with satisfactory results. Essential features of the method are as follows: (1) an enhanced desorption yield due to the mixing of the analyte with metal powder and (2) a high resolution and sensitivity and a low detection limit due to laser resonant ionization and mass spectrometric detection. Application to the analysis of trans-resveratrol in vine leaves and grape skin demonstrated the capabilities of the analytical method reaching detection limits of only few ppb.

Intrinsic resistance of Mycobacterium smegmatis to fluoroquinolones may be influenced by new pentapeptide protein MfpA

The fluoroquinolones (FQ) are used in the treatment of Mycobacterium tuberculosis, but the development of resistance could limit their effectiveness. FQ resistance (FQ(R)) is a multistep process involving alterations in the type II topoisomerases and perhaps in the regulation of efflux pumps, but several of the steps remain unidentified. Recombinant plasmid pGADIV was selected from a genomic library of wild-type (WT), FQ-sensitive M. smegmatis by its ability to confer low-level resistance to sparfloxacin (SPX). In WT M. smegmatis, pGADIV increased the MICs of ciprofloxacin (CIP) by fourfold and of SPX by eightfold, and in M. bovis BCG it increased the MICs of both CIP and SPX by fourfold. It had no effect on the accumulation of (14)C-labeled CIP or SPX. The open reading frame responsible for the increase in FQ(R), mfpA, encodes a putative protein belonging to the family of pentapeptides, in which almost every fifth amino acid is either leucine or phenylalanine. Very similar proteins are also present in M. tuberculosis and M. avium. The MICs of CIP and SPX were lower for an M. smegmatis mutant strain lacking an intact mfpA gene than for the WT strain, suggesting that, by some unknown mechanism, the gene product plays a role in determining the innate level of FQ(R) in M. smegmatis.

Sulfoxide-controlled S(N)2' displacements between cyanocuprates and epoxy vinyl sulfoxides

Two short and convergent routes have been devised for the preparation of enantiomerically pure acyclic epoxy vinyl sulfoxides. These substrates undergo highly regio- and stereoselective S(N)2' displacements with lithium cyanocuprates to give alpha'-alkylated, gamma-oxygenated Z alpha,beta-unsaturated sulfoxides in moderate to good yields and with good to excellent diastereoselectivities. The absolute configuration of the newly formed carbon-carbon bond is primarily controlled by the chiral sulfur atom, which in a nonreinforcing situation can override the intrinsic anti tendency of the vinyl oxirane moiety and forces the cuprate to undergo syn addition. The hydroxy vinyl sulfoxide functionality of the resulting adducts should allow for subsequent asymmetric transformations thus enhancing the synthetic usefulness of this methodology.

Chronic calf pain in athletes due to sural nerve entrapment. A report of 18 cases

We retrospectively analyzed the charts of 13 athletes (18 limbs) who had sural nerve entrapment localized in the passage of the nerve through the superficial sural aponeurosis. There were 11 men and 2 women (average age, 43 years; range, 31 to 59). All patients reported chronic calf pain that was exacerbated during physical exertion. Delay to diagnosis averaged 9 months (range, 5 to 24). Tenderness in the calf was identified along the course of the sural nerve in all cases. In 10 patients (15 limbs) electrodiagnostic testing before surgery was positive. After failure of nonoperative treatment, surgery was conducted under local anesthesia. Neurolysis was performed by incising the superficial sural aponeurosis and the fibrous band in it through which the nerve passes. The results of the operation were evaluated in terms of residual symptoms, ability to return to the former sport, and degree of patient satisfaction. A final follow-up examination was performed an average of 14 months (range, 6 to 30) after the operation. The final result was excellent in 9 limbs (2 bilateral), good in 8 limbs (2 bilateral), and fair in 1 case. The differential diagnosis of sural nerve entrapment in athletes is discussed. Increase in sural muscle mass or development of local fibrous scar tissue compromised the sural nerve in its course through the unyielding and inextensible superficial sural aponeurosis.

Antiviral and antiluteolytic activity of recombinant bovine IFN-omega1 obtained from Pichia pastoris

The gene coding for bovine interferon-omega1 (BoIFN-omega1) was recently cloned and expressed at high levels in the yeast Pichia pastoris. The recombinant BoIFN-omega1 protein shows antiviral activity in different cell lines and has an antiluteolytic effect in cyclic ewes. In this article, we describe a method for purification of BoIFN-omega1 expressed in the methylotrophic yeast P. pastoris and characterization of its activity in vivo. The recombinant protein secreted to the culture medium had low activity because of self-aggregation. BoIFN-omega1 was solubilized using urea and desalting and finally purified by ion exchange chromatography on Q-Sepharose Fast Flow. The yield of purified product was approximately 300 mg/L of fermentation culture, with a specific antiviral activity of 10(8) IU/mg. Its purity was at least 80%. The biologic characterization of purified BoIFN-omega1 was determined by induction of an antiviral state on ewes challenged with 100 lethal doses (LD) of Aujeszky virus and by the extension of the corpus luteum life span and interestrous interval in cyclic cows. Ewes treated with 2 x 106 IU/kg BoIFN-omega1 were protected from Aujeszky virus infection. In cows receiving an intrauterine infusion of 1 mg BoIFN-omega1, equally distributed between the two uterine horns, twice daily from day 14 to day 22 of the experimental estrous cycle, the lifespan of the corpus luteum (25 vs. 19 days) and the interestrous intervals (26 vs. 21 days) were extended when compared with a control group (p < 0.05). We show that recombinant BoIFN-omega1 purified from P. pastoris has high antiviral activity and is an effective antiluteolytic agent in cattle.

Control of ticks resistant to immunization with Bm86 in cattle vaccinated with the recombinant antigen Bm95 isolated from the cattle tick, Boophilus microplus

The recombinant Bm86-containing vaccine Gavac(TM) against the cattle tick Boophilus microplus has proved its efficacy in a number of experiments, especially when combined with acaricides in an integrated manner. However, tick isolates such as the Argentinean strain A, show low susceptibility to this vaccine. In this paper we report on the isolation of the Bm95 gene from the B. microplus strain A, which was cloned and expressed in the yeast Pichia pastoris producing a glycosylated and particulated recombinant protein. This new antigen was effective against different tick strains in a pen trial, including the B. microplus strain A, resistant to vaccination with Bm86. A Bm95-based vaccine was used to protect cattle against tick infestations under production conditions, lowering the number of ticks on vaccinated animals and, therefore, reducing the frequency of acaricide treatments. The Bm95 antigen from strain A was able to protect against infestations with Bm86-sensitive and Bm86-resistant tick strains, thus suggesting that Bm95 could be a more universal antigen to protect cattle against infestations by B. microplus strains from different geographical areas.

Application of the critical molar concentration concept to heat-mediated antigen retrieval in immunohistochemistry

Previously we have applied Scott's critical molar concentration concept to show that divalent cations, especially Mg2+ may be used to measure the affinity of a known monoclonal antibody for its antigen. In this paper we report the application of this same procedure to a study of a series of antigens (three globular proteins and three intermediate filaments). The concept was applied to samples without any previous treatment or after the application of heat-mediated antigen retrieval (using a pressure cooker). Our findings suggest that heat-mediated antigen retrieval sets free protein side-chain(s) that have been masked by formaldehyde fixation. This is reflected in a higher affinity of the antibody for the antigen in question.

Planar Bragg gratings made by excimer-laser modification of ion-exchanged waveguides

The refractive indices of planar silver-ion-exchanged waveguides have been modified by UV excimer laser irradiation (lambda=193 nm) . The effective index changes of the fundamental modes of the waveguides after exposition are as large as 2x10(-2) . The procedure permits the fabrication of integrated optical components in a direct way, with neither the use of standard lithography nor previous sensitizing of the substrate. Optical characterization of the irradiated samples is presented. By the use of appropriate masks, we have fabricated planar Bragg gratings.

Vaccination against ticks (Boophilus spp.): the experience with the Bm86-based vaccine Gavac

The control of tick infestations and the transmission of tick-borne diseases remain a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant B. microplus gut antigen Bm86 have been developed. Our vaccine formulation (Gavac, Heber Biotec S.A., Havana, Cuba) has been registered and is commercially available in Cuba, Colombia, Dominican Republic, Brazil and Mexico. In controlled pen trials, Gavac has been effective for the control of artificial infestations of B. annulatus, B. decoloratus and chemical-sensitive and resistant B. microplus strains from Australia, Africa, America and Iran. In controlled field trials in Cuba, Brazil, Argentina and Mexico, Gavac has shown a 55-100% efficacy in the control of B. microplus infestations in grazing cattle 12-36 weeks after the first vaccination. Field trials under production conditions have been conducted in Cuba, Colombia, Brazil and Mexico in pure and cross-bred cattle herds. The application of Gavac has increased the time between acaricide treatments by an average of 32 /-21 days (P = 0.0005) resulting in important savings for the cattle industry. In Cuba, a cost-effectiveness analysis was conducted in more than 260000 animals. The cost-effectiveness analysis showed a 60% reduction in the number of acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of 23.4 dollars animal(-1) year (-1). These results clearly demonstrate the advantage of vaccination and support the application of Gavac for the control of Boophilus spp. infestations.

Integrated control of acaricide-resistant Boophilus microplus populations on grazing cattle in Mexico using vaccination with Gavac and amidine treatments

Throughout most of the twentieth century, tick infestations on cattle have been controlled with chemical acaricides, typically administered by dipping or spraying. This approach can cause environmental and residue problems and has created a high incidence of acaricide resistance within tick populations in the field. Recently we developed a vaccine against Boophilus microplus employing a recombinant Bm86 antigen preparation (Gavac), (Heber Biotec S.A., Havana, Cuba) which has been shown to induce a protective response in vaccinated animals. Here we show for the first time under field conditions a near 100% control of B. microplus populations resistant to pyrethroids and organophosphates, by an integrated system employing vaccination with Gavac and amidine treatments. This method effectively controls tick infestations while reducing the number of chemical acaricide treatments and consequently the rise of B. microplus populations resistant to chemical acaricides.

Reproductive and safety assessment of vaccination with Gavac against the cattle tick (Boophilus microplus)

Recent developments in cattle tick control have incorporated the use of recombinant Bm86 vaccines against this ectoparasite. The vaccine developed by our group (Gavac) contains an antigen expressed in Pichia pastoris, and has been successfully employed for the control of tick infestations and transmission of tick-borne diseases. Here, we examined the safety and effect of the Gavac vaccine on reproductive parameters in cattle. Toxicity tests in mice and guinea pigs demonstrated the safety of Gavac. To study the adverse effects of vaccination on reproduction, a field trial involving 9,500 animals in Cuba was conducted. The cattle at 3 farms were vaccinated while those on a fourth farm were left unvaccinated and served as the control. Following vaccination, the control of tick infestation and the transmission of babesiosis were used to demonstrate the efficacy of the vaccine. No adverse effects were observed in any of the reproductive parameters studied when comparing the data before and after vaccination with Gavac and between the vaccinated farms and the control farm. These results demonstrate that under the conditions of our study vaccination with Gavac is safe for use on cattle.

Fibrosing mediastinitis: CT and MR findings

The aim of this study is to present the computed tomography (CT) and magnetic resonance (MR) findings in three cases of fibrosing mediastinitis, probably secondary to tuberculosis. Two patients had diffuse involvement of the mediastinum and one patient presented with a posterior mediastinal mass. On CT, the patients with diffuse involvement showed infiltrating soft-tissue masses with multiple foci of dense calcifications. One of these lesions enhanced mildly with contrast and one did not enhance. On MR examination, diffuse masses were of heterogeneous, intermediate and low signal on T1-weighted images (n = 2) and were of homogeneous low signal (n = 1) or heterogeneous (n = 1) signal intensity on T2-weighted images. After administration of Gd-DTPA, these mediastinal masses showed heterogeneous enhancement. The posterior mediastinal mass showed homogeneous pronounced enhancement on CT and was homogeneous with intermediate T1 signal intensity and hypointense T2 signal intensity. The CT findings of an infiltrative or well-defined mediastinal mass with scattered calcifications should suggest the diagnosis of fibrosing mediastinitis in the appropriate clinical setting. Although the appearance of calcification on MR are not specific, this technique provides further information than CT especially in those cases in which the lesions appear noncalcified, because MR imaging revealed areas of low signal intensity characteristic of fibrous tissue.

[Benign fibrous mesothelioma: report of 8 cases]

Benign fibrous mesothelioma (BFM) is a primary, isolated tumor of the pleura. In 80% of patients the tumor originates in the visceral pleura. BFM is rare and localized malignant mesothelioma, whose prognosis and treatment is significantly different, must be considered as a differential diagnosis. We report 8 cases of BFM excised by thoracotomy. In 6 asymptomatic patients, diagnosis was based on radiological images. One patient with a large tumor suffered dyspnea, acropachia and hypertrophic osteoarthropathy. The last patient experienced long-lasting chest pain even though the tumor was small (3 x 3 x 1 cm). Diagnosis was before thoracotomy in 3 cases, 2 by punch biopsy (tru-cut) and the other by thoracoscopy. The results of pleural fluid analysis were nonspecific in 2 of the 3 cases in which pleural effusion was present. Thoracotomy allowed removal of the entire tumor in all patients.

The bovine IFN-omega 1 is biologically active and secreted at high levels in the yeast Pichia pastoris

The gene coding for bIFN-omega 1 was isolated from bovine genomic DNA by polymerase chain reaction (PCR). Recombinant bIFN-omega 1 was expressed in the yeast Pichia pastoris and high levels of the recombinant protein (0.4 mg ml-1) were secreted to the culture media. The obtained bIFN-omega 1 showed a cross-species antiviral activity on four mammalian cell lines of calf, pig, hamster and human origin, but this activity was absent on Madin-Darby canine kidney (MDCK) cells. A delivery carrier was developed to permit a better release of bIFN-omega 1. When compared with a control group, an increase in 6 days in the corpus luteum lifespan was obtained in cyclic ewes following three interferon (IFN) intrauterine administrations on days 9, 10 and 11 post-estrus. In summary, these results demonstrated for the first time that biologically active recombinant bIFN-omega 1 was highly secreted by P. pastoris showing antiviral activity in different cell lines and an antiluteolytic effect in cyclic ewes, with no detrimental effects on the animals.

Effect of particulation on the immunogenic and protective properties of the recombinant Bm86 antigen expressed in Pichia pastoris

The recombinant Bm86 tick antigen expressed in Pichia pastoris is obtained in a highly particulated form, as a distinguish feature of this expression system. This particulated protein, the active principle of the recombinant vaccine Gavac against the cattle tick, have shown high immunogenic and protective properties, probably associated with its own characteristics. To evaluate the effects of particulation on the properties of Bm86, three groups of calves were immunized with particulated or non-particulated recombinant Bm86 and the anti-Bm86 antibody response determined. Animals were challenged with a controlled tick infestation and the protective capacities of both proteins assessed. Humoral immune response and protection in cattle vaccinated with the particulated antigen were higher. These experiments suggested that particulation of the Bm86 expressed in P. pastoris is an important feature for the protective properties of the antigen in vaccine preparations.

Field studies and cost-effectiveness analysis of vaccination with Gavac against the cattle tick Boophilus microplus

The control of tick infestations and the transmission of tick-borne diseases remains a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant Boophilus microplus gut antigen Bm86 have been developed. These vaccines have been shown to control tick infestations in the field. However, extensive field studies investigating the efficacy and cost-effectiveness of vaccination have not been reported and are needed to appraise the effect of this new approach for tick control. Here is reported the results of the application of Gavac in a field trial including more than 260,000 animals in Cuba. In this study the correlation between the antibody response to vaccination and the effect on ticks fertility is determined. Physiological status of the animals was found to affect the primary response to vaccination but not the antibody titers after revaccination. A cost-effectiveness analysis showed a 60% reduction in the number acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of $23.4 animal-1 year-1. These results clearly demonstrate the advantage of vaccination and support the application of Gavac for tick control.

Thermal stability of Artemia HGPRT: effect of substrates on inactivation kinetics

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT, E.C.2.4.2.8) from Artemia cysts exhibits maximum activity at 70 degrees C. Its thermal stability has been examined following enzymatic activity as a function of temperature. Cold-induced renaturation experiments of samples heated at increasing temperatures showed that reversibility of thermal inactivation depends on the incubation time and final temperature. Prolonged incubation of the thermoinactivated enzyme at 0 degree C did not afford any further increase of the catalytic activity at 37 degrees C. The complex substrate PRPP:Mg protects HGPRT from thermal inactivation. However, incubations with hypoxanthine rendered a less thermostable enzyme at any temperature tested. The irreversible inactivation of HGPRT proceeds in two exponential steps. The analysis of the apparent rate constants for the fast and the slow phases, lambda 1 and lambda 2 as per the Lumry and Eyring model suggests the existence of more than three states in the thermal denaturation pathway of the free enzyme. In the presence of PRPP:Mg the irreversible process follows a single exponential and proceeds very slowly below 70 degrees C. PRPP:Mg also protects the enzyme from inactivation by NEM and pCMB, suggesting that -SH groups may be in the vicinity of the active site.

[Urate production in a porcine model of myocardial ischemia-reperfusion]

OBJECTIVE

This study was designed to investigate urate production by swine hearts using an in vivo regionally ischemic-reperfused model.

ANIMALS AND METHODS

Ten female pigs underwent 60 minutes of myocardial ischemia by clamping of the left anterior descending artery and afterwards 120 minutes of reperfusion. Epicardial biopsies and blood samples from coronary sinus were taken before ligation, at the end of ischemic period and 5, 30, 60 and 120 minutes upon reperfusion.

RESULTS

During ischemia, tissue levels of ATP and ADP greatly declined with a subsequent increase in the concentration of AMP, inosine and hypoxanthine (33 +/- 12 vs 93 +/- 17, 26 +/- 8 vs 768 +/- 86 and 32 +/- 10 vs 219 +/- 26 nmol/g dry weight, p < 0.01 for each). Despite the great increase in the hypoxanthine levels, uric acid concentration remained constant (69 +/- 9 vs 32 +/- 12 nmol/g dry weight, NS). Hypoxanthine, xanthine and uric acid concentrations increased in blood samples obtained from the coronary sinus at the end of ischemic period (17.99 vs 31.03 nmol/ml, p < 0.01, 0.29 vs 1.45 nmol/ml, p < 0.05 and 1.20 vs 2.31 nmol/ml, p < 0.01 respectively) and were enhanced upon reperfusion (35.8 and 3.89 nmol/ml for hypoxanthine and uric acid respectively, p < 0.05) without any significant modifications in their concentrations at the arterial level.

CONCLUSION

These results demonstrate that the ischemic-reperfused swine heart produces urate probably outside the myocardium.

[Segmental portal hypertension and cystic tumor of the pancreas]

Isolated obstruction of the splenic vein constitute 5-10% of all patients with portal hypertension. The evaluation of splenic vein patency is important in assessing inflammatory or neoplastic diseases of the pancreas. Accurate preoperative diagnosis is therefore essential to allow the correct choice of operative procedure. A case of isolated splenic vein obstruction with left-sided portal hypertension secondary to cystadenocarcinoma of the pancreas is reported in order to discuss criteria of preoperative diagnosis between benign and malignant cystic lesions of the pancreas.