Study of Coronary Flow Reserve with Intravenous Use of Microbubbles (Contrast Echocardiography) and Adenosine: Protocol for Clinical Application in Patients Suspected of Having Coronary Heart Disease

OBJECTIVE: To test the feasibility, safety and accuracy of the adenosine protocol in the study of myocardial perfusion with microbubbles contrast echocardiography. METHODS: 81 pts (64 male, 60+11 years) were submitted to contrast echocardiography with PESDA (sonicated solution of albumin 20%-1ml, dextrose 5%-12ml and deca-fluorobutane gas-8ml) to study the myocardial perfusion at rest and after bolus injection of adenosine (6 to 18mg) and to coronary angiography within 1 month each other. For each patient 3 left ventricle perfusion beds were considered (total of 243 territories). 208 territories were analyzed and 35 territories were excluded. PESDA was continuously infused (1-2ml/min), titrated for best myocardial contrast. Triggered (1:1) second harmonic imaging was used. RESULTS: Coronary angiography showed 70 flow limiting (> 75%) lesions and 138 no flow limiting lesions. At rest an obvious myocardium contrast enhancement was seen in at least 1 segment of a territory in all patients. After adenosine injection an unquestionable further increase in myocardial contrast was observed in 136 territories (99%) related to no flow limiting lesions, lasting < 10 s, and a myocardial perfusion defect was detected in 68 territories (97%) related to flow limiting lesions. It was observed only 4 false results. There were no serious complications. CONCLUSION: Myocardial perfusion study with PESDA and adenosine protocol is a practical, safe and accurate method to analyze the coronary flow reserve.

Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics

The purpose of the present study was to measure contrast sensitivity to equiluminant gratings using steady-state visual evoked cortical potential (ssVECP) and psychophysics. Six healthy volunteers were evaluated with ssVECPs and psychophysics. The visual stimuli were red-green or blue-yellow horizontal sinusoidal gratings, 5° × 5°, 34.3 cd/m2 mean luminance, presented at 6 Hz. Eight spatial frequencies from 0.2 to 8 cpd were used, each presented at 8 contrast levels. Contrast threshold was obtained by extrapolating second harmonic amplitude values to zero. Psychophysical contrast thresholds were measured using stimuli at 6 Hz and static presentation. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. ssVECP and both psychophysical contrast sensitivity functions (CSFs) were low-pass functions for red-green gratings. For electrophysiology, the highest contrast sensitivity values were found at 0.4 cpd (1.95 ± 0.15). ssVECP CSF was similar to dynamic psychophysical CSF, while static CSF had higher values ranging from 0.4 to 6 cpd (P < 0.05, ANOVA). Blue-yellow chromatic functions showed no specific tuning shape; however, at high spatial frequencies the evoked potentials showed higher contrast sensitivity than the psychophysical methods (P < 0.05, ANOVA). Evoked potentials can be used reliably to evaluate chromatic red-green CSFs in agreement with psychophysical thresholds, mainly if the same temporal properties are applied to the stimulus. For blue-yellow CSF, correlation between electrophysiology and psychophysics was poor at high spatial frequency, possibly due to a greater effect of chromatic aberration on this kind of stimulus.

Congenital Chagas disease of second generation in Santiago, Chile. Report of two cases

Congenital Chagas disease (CChD) has been reported in different countries, mostly in Latin America. In 1987 a fatal case of CChD of second generation (CChDSG) was published. Within a period of six months - 1989-1990 - two cases of CChDSG were diagnosed and studied in the city of Santiago. Two premature newborns, sons of two sisters, with moderate liver and spleen enlargement, were found to have positive serology for Chagas disease and xenodiagnoses. The mothers, urban residents all their lives, without antecedents of triatomine bugs contact or blood transfusions, showed positive serology and xenodiagnoses. Their mother (grandmother of the infants), lived 20 years in a Northern rural Chagas disease endemic locality, in a triatomine infested house. Afterwards, she moved to Santiago, where she married and has resided up to now. Serology and xenodiagnoses were also positive. All the Trypanosoma cruzi infected individuals were successfully treated with nifurtimox.

First- Versus Second-Generation Drug-Eluting Stents in Acute Coronary Syndromes (Katowice-Zabrze Registry)

Abstract Background: There are sparse data on the performance of different types of drug-eluting stents (DES) in acute and real-life setting. Objective: The aim of the study was to compare the safety and efficacy of first- versus second-generation DES in patients with acute coronary syndromes (ACS). Methods: This all-comer registry enrolled consecutive patients diagnosed with ACS and treated with percutaneous coronary intervention with the implantation of first- or second-generation DES in one-year follow-up. The primary efficacy endpoint was defined as major adverse cardiac and cerebrovascular event (MACCE), a composite of all-cause death, nonfatal myocardial infarction, target-vessel revascularization and stroke. The primary safety outcome was definite stent thrombosis (ST) at one year. Results: From the total of 1916 patients enrolled into the registry, 1328 patients were diagnosed with ACS. Of them, 426 were treated with first- and 902 with second-generation DES. There was no significant difference in the incidence of MACCE between two types of DES at one year. The rate of acute and subacute ST was higher in first- vs. second-generation DES (1.6% vs. 0.1%, p < 0.001, and 1.2% vs. 0.2%, p = 0.025, respectively), but there was no difference regarding late ST (0.7% vs. 0.2%, respectively, p = 0.18) and gastrointestinal bleeding (2.1% vs. 1.1%, p = 0.21). In Cox regression, first-generation DES was an independent predictor for cumulative ST (HR 3.29 [1.30-8.31], p = 0.01). Conclusions: In an all-comer registry of ACS, the one-year rate of MACCE was comparable in groups treated with first- and second-generation DES. The use of first-generation DES was associated with higher rates of acute and subacute ST and was an independent predictor of cumulative ST.

Use of sorghum straw (Sorghum bicolor) for second generation ethanol production: pretreatment and enzymatic hydrolysis

Agronomic biomass yields of forage sorghum BRS 655 presented similar results to other energy crops, producing 9 to 12.6 tons/ha (dry mass) of sorghum straw. The objective of this study was to evaluate the lignocellulosic part of this cultivar in terms of its potential in the different unit processes in the production of cellulosic ethanol, measuring the effects of pretreatment and enzymatic hydrolysis. Three types of pre-treatments for two reaction times were conducted to evaluate the characteristics of the pulp for subsequent saccharification. The pulp pretreated by alkali, and by acid followed by delignification, attained hydrolysis rates of over 90%.

Biology of the first generation of a laboratory colony of Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926) (Diptera: Psychodidae)

The phlebotomine sand flies Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926) are very close and may be involved in the transmission of Leishmania spp. Ross, 1903 in Brazil. The biology of the first laboratory-reared generations of these species, descended from insects captured in Além Paraíba (N. intermedia) and Corinto (N. neivai) in the Brazilian state of Minas Gerais, is described here. The captured females were fed on hamsters and maintained individually in rearing pots. Laboratory temperature and relative humidity were maintained at 25-26ºC and 80% respectively. The productivity of the first generation of N. intermedia was greater than that of N. neivai, and its development time clearly shorter, particularly for the second and third larval instars.

Flow analysis-hydride generation-gas phase derivative molecular absorption spectrophotometric determination of antimony in antileishmanial drugs

In the present work, the development of a method based on the coupling of flow analysis (FA), hydride generation (HG), and derivative molecular absorption spectrophotometry (D-EAM) in gas phase (GP), is described in order to determine total antimony in antileishmanial products. Second derivative order (D²224nm) of the absorption spectrum (190 - 300 nm) is utilized as measurement criterion. Each one of the parameters involved in the development of the proposed method was examined and optimized. The utilization of the EAM in GP as detection system in a continuous mode instead of atomic absorption spectrometry represents the great potential of the analytic proposal.

Automatic evaluation and data generation for analytical chemistry instrumental analysis exercises

In general, laboratory activities are costly in terms of time, space, and money. As such, the ability to provide realistically simulated laboratory data that enables students to practice data analysis techniques as a complementary activity would be expected to reduce these costs while opening up very interesting possibilities. In the present work, a novel methodology is presented for design of analytical chemistry instrumental analysis exercises that can be automatically personalized for each student and the results evaluated immediately. The proposed system provides each student with a different set of experimental data generated randomly while satisfying a set of constraints, rather than using data obtained from actual laboratory work. This allows the instructor to provide students with a set of practical problems to complement their regular laboratory work along with the corresponding feedback provided by the system's automatic evaluation process. To this end, the Goodle Grading Management System (GMS), an innovative web-based educational tool for automating the collection and assessment of practical exercises for engineering and scientific courses, was developed. The proposed methodology takes full advantage of the Goodle GMS fusion code architecture. The design of a particular exercise is provided ad hoc by the instructor and requires basic Matlab knowledge. The system has been employed with satisfactory results in several university courses. To demonstrate the automatic evaluation process, three exercises are presented in detail. The first exercise involves a linear regression analysis of data and the calculation of the quality parameters of an instrumental analysis method. The second and third exercises address two different comparison tests, a comparison test of the mean and a t-paired test.

Photic driving in the electroencephalogram of children and adolescents: harmonic structure and relation to the resting state

In order to identify latent bioelectrical oscillators, 15 normal subjects (aged 9-17 years, 8 males, 7 females) were subjected to intermittent photic stimulation. The EEG amplitude spectra corresponding to the 11 fixed frequencies of stimulation presented (3-24 Hz) were combined to form "profiles" of the driving reaction in the right occipital area. The driving response varied with frequency, and was demonstrable in 70-100% of cases (using as criterion peak amplitudes 20% larger than those of the neighbors). The strongest responses were observed at the frequency closest to the alpha peak of the resting EEG. A secondary profile maximum was in the theta band. In 10 subjects, this maximum exceeded half the alpha peak (with an average of 72.4% of the alpha peak), while in the resting spectra, theta amplitudes were much lower than the alpha maxima. This responsiveness in theta activity seems to be characteristic of prepubertal and pubertal subjects. The profiles and resting EEG spectra showed a highly significant Pearson's correlation, with the peak in the theta band of the profiles being the main difference observed between them. The correlation coefficient was significantly correlated with the ratio of the maxima in the theta and alpha bands (R = -0.77, P<0.001). The correlation coefficient between profile and resting spectrum may be a useful indicator in screening methods used to reveal latent cerebral oscillators. Profiles for the second and third harmonics were correlated with those of the first harmonic (fundamental frequency), when considering the corresponding EEG frequencies. Peak frequencies in all three profiles were close to those of the individual's background alpha rhythm, and peak amplitudes in higher harmonics were not much lower than those of the fundamental frequency (mean values of 84 and 63%, for second and third harmonics, respectively).

Brazilian doctors' perspective on the second opinion strategy before a C-section

OBJECTIVE: To describe the opinion of doctors who participated in the Latin American Study on Cesarean section in Brazil regarding the second opinion strategy when faced with the decision of performing a C-section. METHODS: Seventy-two doctors from the hospitals where the study took place (where the second opinion was routinely sought) and 70 from the control group answered a pre-tested self-administered structured questionnaire. Descriptive tables were prepared based on the frequency of relevant variables on opinion of physicians regarding: effectiveness of the application of the second opinion strategy; on whether they would recommend implementation of this strategy and reasons for not recommending it in private institutions; feasibility of the strategy implementation and reasons for not considering this implementation feasible in private institutions. RESULTS: Half of the doctors from the intervention hospitals (50%) and about two thirds of those in the control group (65%) evaluated the second opinion as being or having the potential of being effective/very effective in their institutions. The great majority of those interviewed from both intervention and control hospitals considered this strategy feasible in public (87% and 95% respectively) but not in private hospitals (64% and 70% respectively), mainly because in the latter the doctors would not accept interference from a colleague in their decision-making process. CONCLUSION: Although the second opinion strategy was perceived as effective in reducing C-section rates, doctors did not regard it feasible outside the public health system in Brazil.

Biological and morphological characteristics of Schistosoma mansoni from Ribeira Valley, State of São Paulo, Brazil: I - susceptibility of Biomphalaria tenagophila snail to sympatric S. mansoni strain

In the São Paulo State, Brazil, where the Biomphalaria tenagophila is the intermediate host, the Ribeira Valley is an important endemic schistosomiasis mansoni area. During last eleven years there has been intense control measures focusing on schistosomiasis. The efforts have been concentrated in the municipalities of Pedro de Toledo and Itariri. We determined the susceptibility of B. tenagophila to sympatric strain of S. mansoni, both recently isolated from Itariri field. In 1988, this strain was isolated and maintained in the experimental model: Swiss mice - sympatric B. tenagophila. The second generation of the worm was evaluated. The snail were divided in the three groups of 60 snails each. One group was exposed to 1 miracidium and other to 10. The third group was the control. The mortality and the shedding of cercariae were checked during 78 days. After that, the positive snails were observed until they ceased to shed cercariae. The exposed molluscs showed mortality rates of 23% and 31% and infection indexes were of 8% and 60% to 1 and 10 miracidia respectively. The mortality was of 22% in the control group. The periods of shedding cercariae in the two groups were 82 and 104 days. We can conclude that B. tenagophila is an effective intermediate host to the sympatric strain of S. mansoni sympatric strain

Anti-HCV related to HCV PCR and risk factors analysis in a blood donor population of Central Brazil

Data concerning HCV infection in Central Brazil are rare. Upon testing 2,350 voluntary blood donors from this region, we found anti-HCV prevalence rates of 2.2% by a second generation ELISA and 1.4% after confirmation by a line immunoassay. Antibodies against core, NS4, and NS5 antigens of HCV were detected in 81.8%, 72.7%, and 57.5%, respectively, of the positive samples in the line immunoassay. HCV viremia was present in 76.6% of the anti-HCV-positive blood donors. A relation was observed between PCR positivity and serum reactivity in recognizing different HCV antigens in the line immunoassay. The majority of the positive donors had history of previous parenteral exposure. While the combination of ALT>50 IU/l and anti-HBc positivity do not appear to be good surrogate markers for HCV infection, the use of both ALT anti-HCV tests is indicated in the screening of Brazilian blood donors.

Cutaneous protothecosis: report of the second Brazilian case

The present report describes a case of cutaneous protothecosis caused by Prototheca wickerhamii in a non-immunocompromised female from the state of Bahia, Brazil. This is the second case described in Brazil. Dermatological examination revealed diffusely infiltrated erythematous plaques on the flexor aspect of the right arm and forearm. The authors emphasize the pathological aspects that can lead to misdiagnosis this condition. The patient was successfully treated with fluconazole.

Seroprevalence of Helicobacter pylori infection in chronic chagasic patients, and in the rural and urban population from Uberlândia, Minas Gerais, Brazil

As patients with chronic Chagas disease exhibit morphological and functional changes of the stomach (hypomotility and hypochlorhydria), malnutrition, immunological deficiency and high prevalence of peptic disease associated to Helicobater pylori infection, the purpose of this study was to evaluate if the prevalence of H. pylori infection in chronic chagasic is higher than in non-chagasic individuals in the urban and rural population from Uberlândia, MG, Brazil. Serological determination of IgG antibodies to H. pylori was performed using a second-generation ELISA. Thus, 598 people were evaluated: 128 chagasic (CG), 222 non-chagasic living in urban area (U-NCG) and 248 non-chagasic living in rural area (R-NCG). Regarding the age range from 21 to 50 years, the prevalence of H. pylori infection in the CG (85.1%) was significantly higher than in the U-NCG (56.3%, p < 0.01) and the R-NCG (67.4%, p < 0.05). In the patients over 50 years, the prevalence in the CG (86.4%) was similar to the U-NCG (78.8%) and R-NCG (86.1%). Similar results were also found between the U-NCG and R-NCG for all age ranges, with prevalence rates of 29.1% and 35.3% for the age range from 5 to 13 years, and 47.2% and 40% for that from 14 to 20 years, respectively. We conclude that chagasic patients showed a higher seroprevalence of H. pylori infection than non-chagasic individuals, in the age range from 21 to 50 years, and that the prevalence of this infection was similar in the studied urban and rural non-chagasic population.