Acetylcholine and bradykinin enhance hypotension and affect the function of remodeled conduit arteries in SHR and SHR treated with nitric oxide donors

Discrepancy was found between enhanced hypotension and attenuated relaxation of conduit arteries in response to acetylcholine (ACh) and bradykinin (BK) in nitric oxide (NO)-deficient hypertension. The question is whether a similar phenomenon occurs in spontaneously hypertensive rats (SHR) with a different pathogenesis. Wistar rats, SHR, and SHR treated with NO donors [molsidomine (50 mg/kg) or pentaerythritol tetranitrate (100 mg/kg), twice a day, by gavage] were studied. After 6 weeks of treatment systolic blood pressure (BP) was increased significantly in experimental groups. Under anesthesia, the carotid artery was cannulated for BP recording and the jugular vein for drug administration. The iliac artery was used for in vitro studies and determination of geometry. Compared to control, SHR showed a significantly enhanced (P < 0.01) hypotensive response to ACh (1 and 10 µg, 87.9 ± 6.9 and 108.1 ± 5.1 vs 35.9 ± 4.7 and 64.0 ± 3.3 mmHg), and BK (100 µg, 106.7 ± 8.3 vs 53.3 ± 5.2 mmHg). SHR receiving NO donors yielded similar results. In contrast, maximum relaxation of the iliac artery in response to ACh was attenuated in SHR (12.1 ± 3.6 vs 74.2 ± 8.6% in controls, P < 0.01). Iliac artery inner diameter also increased (680 ± 46 vs 828 ± 28 µm in controls, P < 0.01). Wall thickness, wall cross-section area, wall thickness/inner diameter ratio increased significantly (P < 0.01). No differences were found in this respect among SHR and SHR treated with NO donors. These findings demonstrated enhanced hypotension and attenuated relaxation of the conduit artery in response to NO activators in SHR and in SHR treated with NO donors, a response similar to that found in NO-deficient hypertension.

Does a circadian variation occur in myocardial ischemia over 48 hours in patients with unstable angina?

OBJECTIVE: To study the incidence of and variation in myocardial ischemia over 48 hours in patients with unstable angina. METHODS: Thirty-nine patients with unstable angina underwent long-term electrocardiography for 48 hours. The number of events and the period of time of ischemia (in minutes) were analyzed for the 48 hours, in two periods of 24 hours, and in periods of 4 hours. RESULTS: We analyzed 1755.8 hours of monitoring tapes, and ischemic episodes were detected in 18 (46.2%) patients, corresponding to 173 ischemic episodes, allowing the evaluation of 1304 minutes of ischemia.only 4 of which were (2.2%) symptomatic, Considering the entire period of time of recording and the predetermined time intervals, we observed a higher number of ischemic episodes (38) and a longer duration of ischemia (315.4 minutes) between 11:00 am and 3:00 pm. However, no significant differences occurred among the values in the different intervals. CONCLUSION: Long-term electrocardiography over 48 hours showed a high incidence (97.8%) of silent ischemic episodes in patients with unstable angina. No evidence of a circadian variation of myocardial ischemia in unstable angina was observed.

Programa de gerenciamento de resíduos dos laboratórios de graduação da Universidade Regional Integrada do Alto Uruguai e das Missões - Campus Erechim

This work presents a proposal for the management of residues from teaching laboratories. The main goals of the proposal are: scale reduction of experiments, reuse of residues as raw materials for new experiments and appropriate treatment and storage of residues. The methodology includes standardized labels for residue classification and registration of experimental classes and their residues in files. The management seemed to be efficient, resulting in a reduction of the amount of reagents utilized and residues generated, and an increase of reutilization of residues. A considerable decrease of needed storage space and suitable methods for correct residue disposal were achieved. We expect that all laboratories, including those exclusively for research activities, become involved, in a near future, in the Residue Management Project of URI - Campus Erechim.

Identification of the main generator source of longitudinal muscle contraction in the earthworm ventral nerve cord

The main generator source of a longitudinal muscle contraction was identified as an M (mechanical-stimulus-sensitive) circuit composed of a presynaptic M-1 neuron and a postsynaptic M-2 neuron in the ventral nerve cord of the earthworm, Amynthas hawayanus, by simultaneous intracellular response recording and Lucifer Yellow-CH injection with two microelectrodes. Five-peaked responses were evoked in both neurons by a mechanical, but not by an electrical, stimulus to the mechanoreceptor in the shaft of a seta at the opposite side of an epidermis-muscle-nerve-cord preparation. This response was correlated to 84% of the amplitude, 73% of the rising rate and 81% of the duration of a longitudinal muscle contraction recorded by a mechano-electrical transducer after eliminating the other possible generator sources by partitioning the epidermis-muscle piece of this preparation. The pre- and postsynaptic relationship between these two neurons was determined by alternately stimulating and recording with two microelectrodes. Images of the Lucifer Yellow-CH-filled M-1 and M-2 neurons showed that both of them are composed of bundles of longitudinal processes situated on the side of the nerve cord opposite to stimulation. The M-1 neuron has an afferent process (A1) in the first nerve at the stimulated side of this preparation and the M-2 neuron has two efferent processes (E1 and E3) in the first and third nerves at the recording side where their effector muscle cell was identified by a third microelectrode.

The study of insect blood-feeding behaviour: 2. Recording techniques and the use of flow charts

This paper continues a discussion of approaches and methodologies we have used in our studies of feeding in haematophagous insects. Described are techniques for directly monitoring behaviour: electrical recording of feeding behaviour via resistance changes in the food canal, optical methods for monitoring mouthpart activity, and a computer technique for behavioural event recording. Also described is the use of "flow charts" or "decision diagrams" to model interrelated sequences of behaviours.

Validity and reliability of a health care service evaluation instrument for tuberculosis

OBJECTIVE To evaluate the validity and reliability of an instrument that evaluates the structure of primary health care units for the treatment of tuberculosis.METHODS This cross-sectional study used simple random sampling and evaluated 1,037 health care professionals from five Brazilian municipalities (Natal, state of Rio Grande do Norte; Cabedelo, state of Paraíba; Foz do Iguaçu, state of Parana; Sao José do Rio Preto, state of Sao Paulo, and Uberaba, state of Minas Gerais) in 2011. Structural indicators were identified and validated, considering different methods of organization of the health care system in the municipalities of different population sizes. Each structure represented the organization of health care services and contained the resources available for the execution of health care services: physical resources (equipment, consumables, and facilities); human resources (number and qualification); and resources for maintenance of the existing infrastructure and technology (deemed as the organization of health care services). The statistical analyses used in the validation process included reliability analysis, exploratory factor analysis, and confirmatory factor analysis.RESULTS The validation process indicated the retention of five factors, with 85.9% of the total variance explained, internal consistency between 0.6460 and 0.7802, and quality of fit of the confirmatory factor analysis of 0.995 using the goodness-of-fit index. The retained factors comprised five structural indicators: professionals involved in the care of tuberculosis patients, training, access to recording instruments, availability of supplies, and coordination of health care services with other levels of care. Availability of supplies had the best performance and the lowest coefficient of variation among the services evaluated. The indicators of assessment of human resources and coordination with other levels of care had satisfactory performance, but the latter showed the highest coefficient of variation. The performance of the indicators “training” and “access to recording instruments” was inferior to that of other indicators.CONCLUSIONS The instrument showed feasibility of application and potential to assess the structure of primary health care units for the treatment of tuberculosis.

The effect of antioxidant properties of aqueous garlic extract and Nigella sativa as anti-schistosomiasis agents in mice

The aim of this study was to assess the antioxidant and anti-schistosomal activities of the garlic extract (AGE) and Nigella sativa oil (NSO) on normal and Schistosoma mansoni-infected mice. AGE (125 mg kg-1, i.p.) and NSO (0.2 mg kg-1, i.p.) were administrated separately or in combination for successive 28 days, starting from the 1st day post infection (pi). All mice were sacrificed at weeks 7 pi. Hematological and biochemical parameters including liver and kidney functions were measured to assess the progress of anemia, and the possibility of the tissue damage. Serum total protein level, albumin, globulin and cholesterol were also determined. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in the liver tissues as biomarkers for oxidative and reducing status, respectively. The possible effect of the treatment regimens on Schistosoma worms was evaluated by recording percentage of the recovered worms, tissue egg and oogram pattern. Result showed that, protection with AGE and NSO prevented most of the hematological and biochemical changes and markedly improved the antioxidant capacity of schistosomiasis mice compared to the infected-untreated ones. In addition, remarkable reduction in worms, tissue eggs and alteration in oogram pattern were recorded in all the treated groups. The antioxidant and antischistosomal action of AGE and NSO was greatly diverse according to treatment regimens. These data point to these compounds as promising agents to complement schistosomiasis specific treatment.

Parity and influence of abiotic factors on Anopheles in the Manso dam, State of Mato Grosso, Brazil

Introduction This study examined the parity of Anopheles mosquitoes and the influence of abiotic factors on the distribution of these mosquitoes in the Manso dam, Mato Grosso, Brazil. Methods The anophelines were captured using the Human Attraction Technique for 12 h, while recording the temperature and relative humidity. Parity was determined by examining the conditions of the filaments. Results Anopheles darlingi and Anopheles triannulatus accounted for 98.5% of the anophelines, with 88% of these being parous. Conclusions Sudden variations in weather could be the cause of shifts from the total absence of mosquitoes to the appearance of females in abundance over a three-day period.

External quality assessment in the voluntary counseling and testing centers in the Brazilian Amazon using dried tube specimens: results of an effectiveness evaluation

INTRODUCTION : In 2011, the Brazilian Ministry of Health rolled out a program for the external quality assessment of rapid human immunodeficiency virus (HIV) tests using the dried tube specimen (DTS) method (EQA-RT/DTS-HIV). Our objective was to evaluate the implementation of this program at 71 voluntary counseling and testing centers (VCTCs) in the Brazilian Legal Amazonian area one year after its introduction. METHODS : Quantitative and qualitative study that analyzed secondary data and interviews with healthcare workers (HCWs) (n=39) and VCTC coordinators (n=32) were performed. The assessment used 18 key indicators to evaluate the three dimensions of the program's logical framework: structure, process, and result. Each indicator was scored from 1-4, and the aggregate results corresponding to the dimensions were expressed as proportions. The results were compared to the perceptions of the HCWs and coordinators regarding the EQA-RT/DTS-HIV program. RESULTS: The aggregate scores for the three dimensions of structure, process, and result were 91.7%, 78.6%, and 95%, respectively. The lowest score in each dimension corresponded to a different indicator: access to Quali-TR online system 39% (structure), registration in Quali-TR online system 38.7% (process), and VCTC completed the full process in the program's first round 63.4% (result). Approximately 36% of the HCWs and 52% of the coordinators reported enhanced trust in the program for its rapid HIV testing performance. CONCLUSIONS: All three program dimensions exhibited satisfactory results (>75%). Nevertheless, the study findings highlight the need to improve certain program components. Additionally, long-term follow-ups is needed to provide a more thorough picture of the process for external quality assessment.

Treatment of atrial fibrillation with radiofrequency ablation and simultaneous multipolar mapping of the pulmonary veins

OBJECTIVE: To demonstrate the feasibility and safety of simultaneous catheterization and mapping of the 4 pulmonary veins for ablation of atrial fibrillation. METHODS: Ten patients, 8 with paroxysmal atrial fibrillation and 2 with persistent atrial fibrillation, refractory to at least 2 antiarrhythmic drugs and without structural cardiopathy, were consecutively studied. Through the transseptal insertion of 2 long sheaths, 4 pulmonary veins were simultaneously catheterized with octapolar microcatheters. After identification of arrhythmogenic foci radiofrequency was applied under angiographic or ultrasonographic control. RESULTS: During 17 procedures, 40 pulmonary veins were mapped, 16 of which had local ectopic activity, related or not with the triggering of atrial fibrillation paroxysms. At the end of each procedure, suppression of arrhythmias was obtained in 8 patients, and elimination of pulmonary vein potentials was accomplished in 4. During the clinical follow-up of 9.6±3 months, 7 patients remained in sinus rhythm, 5 of whom were using antiarrhythmic drugs that had previously been ineffective. None of the patients had pulmonary hypertension or evidence of stenosis in the pulmonary veins. CONCLUSION: Selective and simultaneous catheterization of the 4 pulmonary veins with microcatheters for simultaneous recording of their electrical activity is a feasible and safe procedure that may help ablation of atrial fibrillation.

Prevention of Pazopanib-Induced Prolonged Cardiac Repolarization and Proarrhythmic Effects

Background: Pazopanib (PZP) may induce prolonged cardiac repolarization and proarrhythmic effects, similarly to other tyrosine kinase inhibitors. Objectives: To demonstrate PZP-induced prolonged cardiac repolarization and proarrhythmic electrophysiological effects and to investigate possible preventive effects of metoprolol and diltiazem on ECG changes (prolonged QT) in an experimental rat model. Methods: Twenty-four Sprague-Dawley adult male rats were randomly assigned to 4 groups (n = 6). The first group (normal group) received 4 mL of tap water and the other groups received 100 mg/kg of PZP (Votrient® tablet) perorally, via orogastric tubes. After 3 hours, the following solutions were intraperitoneally administered to the animals: physiological saline solution (SP), to the normal group and to the second group (control-PZP+SP group); 1 mg/kg metoprolol (Beloc, Ampule, AstraZeneca), to the third group (PZP+metoprolol group); and 1mg/kg diltiazem (Diltiazem, Mustafa Nevzat), to the fourth group (PZP+diltiazem group). One hour after, and under anesthesia, QTc was calculated by recording ECG on lead I. Results: The mean QTc interval values were as follows: normal group, 99.93 ± 3.62 ms; control-PZP+SP group, 131.23 ± 12.21 ms; PZP+metoprolol group, 89.36 ± 3.61 ms; and PZP+diltiazem group, 88.86 ± 4.04 ms. Both PZP+metoprolol and PZP+diltiazem groups had significantly shorter QTc intervals compared to the control-PZP+SP group (p < 0.001). Conclusion: Both metoprolol and diltiazem prevented PZP-induced QT interval prolongation. These drugs may provide a promising prophylactic strategy for the prolonged QTc interval associated with tyrosine kinase inhibitor use.

Ambulatory Blood Pressure Monitoring: Five Decades of More Light and Less Shadows

Abstract Casual blood pressure measurements have been extensively questioned over the last five decades. A significant percentage of patients have different blood pressure readings when examined in the office or outside it. For this reason, a change in the paradigm of the best manner to assess blood pressure has been observed. The method that has been most widely used is the Ambulatory Blood Pressure Monitoring - ABPM. The method allows recording blood pressure measures in 24 hours and evaluating various parameters such as mean BP, pressure loads, areas under the curve, variations between daytime and nighttime, pulse pressure variability etc. Blood pressure measurements obtained by ABPM are better correlated, for example, with the risks of hypertension. The main indications for ABPM are: suspected white coat hypertension and masked hypertension, evaluation of the efficacy of the antihypertensive therapy in 24 hours, and evaluation of symptoms. There is increasing evidence that the use of ABPM has contributed to the assessment of blood pressure behaviors, establishment of diagnoses, prognosis and the efficacy of antihypertensive therapy. There is no doubt that the study of 24-hour blood pressure behavior and its variations by ABPM has brought more light and less darkness to the field, which justifies the title of this review.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 2 - Attempts to upgrade the reliability and the efficacy of xenodiagnosis in chronic Chagas' disease

In order to upgrade the reliability of xenodiagnosis, attention has been directed towards population dynamics of the parasite, with particular interest for the following factors: 1. Parasite density which by itself is not a research objective, but by giving an accurate portrayal of parasite development and multiplication, has been incorporated in screening of bugs for xenodiagnosis. 2. On the assumption that food availability might increase parasite density, bugs from xenodiagnosis have been refed at biweekly intervals on chicken blood. 3. Infectivity rates and positives harbouring large parasite yields were based on gut infections, in which the parasite population comprised of all developmental forms was more abundant and easier to detect than in fecal infections, thus minimizing the probability of recording false negatives. 4. Since parasite density, low in the first 15 days of infection, increases rapidly in the following 30 days, the interval of 45 days has been adopted for routine examination of bugs from xenodiagnosis. By following the enumerated measures, all aiming to reduce false negative cases, we are getting closer to a reliable xenodiagnostic procedure. Upgrading the efficacy of xenodiagnosis is also dependent on the xenodiagnostic agent. Of 9 investigated vector species, Panstrongylus megistus deserves top priority as a xenodiagnostic agent. Its extraordinary capability to support fast development and vigorous multiplication of the few parasites, ingested from the host with chronic Chagas' disease, has been revealed by the strikingly close infectivity rates of 91.2% vs. 96.4% among bugs engorged from the same host in the chronic and acute phase of the disease respectively (Table V), the latter comporting an estimated number of 12.3 x 10[raised to the power of 3] parasites in the circulation at the time of xenodiagnosis, as reported previously by the authors (1982).

Successful vaccination against Boophilus microplus and Babesia bovis using recombinat antigens

Current methods for the control of the cattle tick Boophils microplus and the agent of bovine babesiosis, Babesia bovis are unsatisfactory. Effective immunological control of both parasites would have great advantages. However, naturally acquired immunity to the tick is generally unable to prevent serious production losses. A vaccine against the tick, based on a novel form of immunization, is being developed. A protective antigen has been isolated from the tick, characterized and produced as an effective, recombinant protein. A vaccine incorporating this antigen is currently undergoing field trials. In the Australian situation, improved tick control will probably increase endemic instability with respect to B. bovis. Fortunately, a trivalent, recombinant B. bovis vaccine has also been developed. This too is now undergoing pre-registration field trials.

Seasonality of Lutzomyia intermedia and Lutzomyia whitmani (Diptera: Psychodidae: Phlebotominae), occurring sympatrically in area of cutaneous leishmaniasis in the State of Rio de Janeiro, Brazil

Lutzomyia intermedia and Lutzomyia whitmani occur sympatrically in the district of Posse, municipality of Petrópolis, in the State of Rio de Janeiro (114 km from the city of Rio de Janeiro), where sand flies were captured weekly for three consecutive years in both the peridomicile and forest, in two first years from 18:00 to 22:00 h, using a Shannon trap and CDC light traps. The anthropophilic habit was assessed by recording the specimens that bit the human captors. Considering the different capture types and sites, the following species were identified: Brumptomyia brumpti, B. cardosoi, B. guimaraesi, Lutzomyia amarali, L. longipalpis, L. microps, L. costalimai, L. edwardsi, L. firmatoi, L. migonei, L. termitophila, L. tupynambai, L. fischeri, L. pessoai, L. lutziana, L. shannoni, L. barrettoi, L. intermedia, L. whitmani, L. lloydi, and L. minasensis. L. intermedia (38.3%) and L. whitmani (38.6%) predominated. L. intermedia predominated in the peridomicile, where it displayed more intense anthropophily, while L. whitmani displayed greater density in the banana plantations and forest, preferential sites for biting humans. Studies on seasonality showed that while L. intermedia displayed greater density in the hottest months of the year (December, January, and February), L. whitmani was abundant in the coolest months (June, July, and August), although both occurred throughout the year.