VIROLOGICAL AND SEROLOGICAL DIAGNOSIS OF RABIES IN BATS FROM AN URBAN AREA IN THE BRAZILIAN AMAZON

The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c² = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.     

Sources of Variability in the Detection of Cerebral Emboli with Transcranial Doppler During Cardiac Surgery

OBJECTIVE: The application of intensity thresholds for embolus detection with transcranial Doppler (TCD) can exclude from analysis an unrecognized proportion of high-intensity transient signals (HITS))whose intensities are below the threshold. The lack of consistent threshold criteria between clinical trials may explain part of the discrepancy in the reported HITS counts. We investigated the effect of choosing different thresholds on the sensitivity and specificity of detecting HITS during cardiopulmonary bypass (CPB). METHODS: Two observers independently analyzed TCD recordings from 8 patients under CPB. Doppler signals were classified as true HITS, equivocal HITS, artifacts, and Doppler speckles according to preestablished criteria. The relative intensity of Doppler signals was measured by two different methods (TCD software vs manual). Receiver Operating Characteristic curves determined the optimal threshold for each of the two intensity methods. RESULTS: Reviewers achieved agreement in 96% of 2190 Doppler signals (kappa = 0.90). Relative intensities calculated with the TCD-software method were 3 dB (95% CI: 3.0-3.4) higher than the manual method. The optimal threshold was found at 10 dB (sensitivity: 99%; specificity: 90.8%) with the software method and at 7 dB with the manual method (sensitivity: 96%; specificity: 83%). The use of an intensity threshold 2 dB higher than the optimal increased the rejection of true HITS by 8% and 14%, respectively. CONCLUSIONS: Using intensity thresholds higher than the optimal for embolus detection decreases HITS counts. Choosing a threshold depends on the type of method used for measuring the signal intensity. Uniform threshold criteria and comparative studies between different Doppler devices are necessary for making clinical trials more comparable.     

Pericardial effusion complicating breast cancer.

Thirty-five patients with metastatic breast cancer and pericardial effusions are described. They were treated with specific endocrine or chemotherapy. Twenty-two (63%) had presented in cardiac tamponade and were rapidly relieved by pericardiocentesis. Eighteen (82%) of these required no further local treatment, 2 obtained relief from a second aspiration and 2 needed additional treatment (intrapericardial bleomycin instillation and surgical pleuropericardial window). The median survival was 13.2 months. No patient relapsed again in the pericardium, suggesting that their prognosis was that of the underlying disease. Cardiac tamponade should be considered in any breathless patient with malignancy. In breast cancer, periocardiocentesis is lifesaving and systemic treatment can usefully prolong life.     

Additive effects of CD59 expression in Gal knockout mice in vitro but not in an ex vivo model

Abstract: Transgenic expression of the human complement regulatory molecule CD59 in mice and genetic deletion of the major xenoantigen galactose α 1,3 galactose (Gal KO) each resulted in partial protection of spleen cells from lysis by human serum. These protective effects were additive when the two genetic modifications were combined. However, when the effects of these genetic modifications were examined in an ex vivo model in which mouse hearts were perfused with human plasma, it was Gal KO which was the modification which determined protection. CD59 expression alone was not protective and CD59 expression in combination with Gal knockout did not result in a significant additional increase in protection over and above that provided by Gal knockout alone. The likely explanation for this discrepancy between the in vitro and ex vivo data is that the H2-K^b promoter used to drive CD59 expression results I in substantially less expression on endothelium than on spleen cells.     

Ethics roundtable debate: Patients and surrogates want 'everything done' – what does 'everything' mean?

Highly complex and specialized care plans sometimes overwhelm the comprehension of patients and families. Many optimistic surrogates of critically ill patients err on the side of desiring that everything be done but with a nebulous idea of what 'everything' entails. Physicians must work closely to educate surrogates as to the benefits versus the risks of treatment. Our roundtable experts ponder the question of whether providers possess the authority to interpret unilaterally the nature of requests for everything.     

Reappraisal of the baseline bone scan in breast cancer

Baseline staging bone scans in 1,267 consecutive women with breast cancer attending a single clinic between 1980 and 1986 were reviewed. 0.3% of patients with T1, 3% with T2, 8% with T3, 13% with T4 tumors and none of those with Stage 1, 3% with Stage 2, 7% with Stage 3, and 47% with Stage 4 disease had a positive scan due to bone metastases. Two hundred eight-nine (23%) had bone scan abnormalities secondary to radiologically confirmed benign bone disease. In 20 patients, no cause for a bone scan abnormality could be found after a median follow-up of 3.50 yr, a false-positive frequency of 1.6%. The false-negative rate was 0.08%. It is concluded that patients with tumors less than 2 cm are most unlikely to have a positive scan. In this instance, scans are not required routinely. However, we recommend a baseline scan in all patients with Stage 2, 3, or 4 disease.     

Chemotherapy of advanced breast cancer: outcome and prognostic factors.

The outcome for 758 consecutive patients who had received one or more chemotherapy regimens for recurrent or metastatic breast cancer is presented. The response rate following first line treatment was 34%. Median duration of response was 7.8 months, median time to progression was 3.7 months and median survival was 7.9 months. The only factor predicting for response, of factors recorded at presentation and at initiation of chemotherapy, was the use of anthracycline based regimens, though this may reflect the patient selection policy. Initial disease free interval, presence of liver metastases and use of anthracyclines were significantly related to time to progression. Several factors related to survival following first chemotherapy, but anthracycline usage showed only a very weak correlation. One third of patients (249/758) received two or more chemotherapy regimens. The response rate (16%) and median time to progression (2.3 months) were significantly worse than for first line treatment. The outcome after third line chemotherapy was very similar to that observed following second line treatment. Achievement of an objective response with first line chemotherapy predicted for second response, but with insufficient power to be of use in selecting patients for subsequent chemotherapy. Time to progression following first line chemotherapy did not influence that after second line treatment.     

Molecular peculiarities of the lytA gene isolated from clinical pneumococcal strains that are bile insoluble

The autolytic LytA amidase from 12 bile (deoxycholate)-insoluble streptococcal isolates (formerly classified as atypical Streptococcus pneumoniae) showing different antibiotic resistance patterns was studied. These atypical strains, which autolyze at the end of the stationary phase of growth, contain highly divergent lytA alleles (pairwise evolutionary distances of about 20%) compared to the lytA alleles of typical pneumococci. The atypical LytA amidases exhibit a peculiar deletion of two amino acids responsible for cell wall anchoring in the carboxy-terminal domain and have a reduced specific activity. These enzymes were inhibited by 1% deoxycholate but were activated by 1% Triton X-100, a detergent that could be used as an alternative diagnostic test for this kind of strain. Preparation of functional chimeric enzymes, PCR mutagenesis, and gene replacements demonstrated that the characteristic bile insolubility of these atypical strains was due to their peculiar carboxy-terminal domain and that the 2-amino-acid deletion was responsible for the inhibitory effect of deoxycholate. However, the deletion alone did not affect the specific activity of LytA. A detailed characterization of the genes encoding the 16S rRNA and SodA together with multilocus sequence typing indicated that the strains studied here are not a single clone and, although they cannot be strictly classified as typical pneumococci, they represent a quite diverse pool of organisms closely related to S. pneumoniae. The clinical importance of these findings is underlined by the role of the lytA gene in shaping the course of pneumococcal diseases. This study can also contribute to solving diagnostic problems and to understanding the evolution and pathogenic potential of species of the Streptococcus mitis group.