Ambulatory blood pressure and Doppler echocardiographic indexes of borderline hypertensive men presenting an exaggerated blood pressure response during dynamic exercise

Borderline hypertension (BH) has been associated with an exaggerated blood pressure (BP) response during laboratory stressors. However, the incidence of target organ damage in this condition and its relation to BP hyperreactivity is an unsettled issue. Thus, we assessed the Doppler echocardiographic profile of a group of BH men (N = 36) according to office BP measurements with exaggerated BP in the cycloergometric test. A group of normotensive men (NT, N = 36) with a normal BP response during the cycloergometric test was used as control. To assess vascular function and reactivity, all subjects were submitted to the cold pressor test. Before Doppler echocardiography, the BP profile of all subjects was evaluated by 24-h ambulatory BP monitoring. All subjects from the NT group presented normal monitored levels of BP. In contrast, 19 subjects from the original BH group presented normal monitored BP levels and 17 presented elevated monitored BP levels. In the NT group all Doppler echocardiographic indexes were normal. All subjects from the original BH group presented normal left ventricular mass and geometrical pattern. However, in the subjects with elevated monitored BP levels, fractional shortening was greater, isovolumetric relaxation time longer, and early to late flow velocity ratio was reduced in relation to subjects from the original BH group with normal monitored BP levels (P<0.05). These subjects also presented an exaggerated BP response during the cold pressor test. These results support the notion of an integrated pattern of cardiac and vascular adaptation during the development of hypertension.

Diverse effects of renal denervation on ventricular hypertrophy and blood pressure in DOCA-salt hypertensive rats

Cardiac hypertrophy that accompanies hypertension seems to be a phenomenon of multifactorial origin whose development does not seem to depend on an increased pressure load alone, but also on local growth factors and cardioadrenergic activity. The aim of the present study was to determine if sympathetic renal denervation and its effects on arterial pressure level can prevent cardiac hypertrophy and if it can also delay the onset and attenuate the severity of deoxycorticosterone acetate (DOCA)-salt hypertension. DOCA-salt treatment was initiated in rats seven days after uninephrectomy and contralateral renal denervation or sham renal denervation. DOCA (15 mg/kg, sc) or vehicle (soybean oil, 0.25 ml per animal) was administered twice a week for two weeks. Rats treated with DOCA or vehicle (control) were provided drinking water containing 1% NaCl and 0.03% KCl. At the end of the treatment period, mean arterial pressure (MAP) and heart rate measurements were made in conscious animals. Under ether anesthesia, the heart was removed and the right and left ventricles (including the septum) were separated and weighed. DOCA-salt treatment produced a significant increase in left ventricular weight/body weight (LVW/BW) ratio (2.44 ± 0.09 mg/g) and right ventricular weight/body weight (RVW/BW) ratio (0.53 ± 0.01 mg/g) compared to control (1.92 ± 0.04 and 0.48 ± 0.01 mg/g, respectively) rats. MAP was significantly higher (39%) in DOCA-salt rats. Renal denervation prevented (P>0.05) the development of hypertension in DOCA-salt rats but did not prevent the increase in LVW/BW (2.27 ± 0.03 mg/g) and RVW/BW (0.52 ± 0.01 mg/g). We have shown that the increase in arterial pressure level is not responsible for cardiac hypertrophy, which may be more related to other events associated with DOCA-salt hypertension, such as an increase in cardiac sympathetic activity.

Improving the environmental performance of bedding products by using life cycle assessment at the design stage

Improvement of the environmental performance of processes and products is a common objective in industry, and has been receiving increased attention in recent years. The main objective of this work is to evaluate the potential environmental impact of two bedding products, a polyurethane foam mattress (PFM) and a pocket spring mattress (PSM). These two types are the most common mattresses used in Europe. A Life Cycle Assessment (LCA) shows that the PFM has a higher environmental impact than the PSM. For both products the main cause of environmental impact is the manufacturing process, respectively the polyurethane foam block moulding process for the PFM, and the pocket spring nucleus process for the PSM. A scenario analysis shows the possibility of reducing the environmental impact of the products’ life cycle using an alternative End-of-Life scenario, resorting to incineration rather than landfill. Two strategies were also studied in order to reduce the environmental impact of the PFM: (1) reutilization of foam that was sent to the waste system management, and (2) a 20% weight reduction of the polyurethane foam. The second strategy has proven to be the most effective.

Mechatronic system for ABO human blood typing

In medical emergency situations, when a patient needs a blood transfusion, the universal blood type O− is administered. This procedure may lead to the depletion of stock reserves of O− blood. Nowadays, there is no commercial equipment capable of determining the patient's blood type in situ, in a fast and reliable process. Human blood typing is usually performed through the manual test, which involves a macroscopic observation and interpretation of the results by an analyst. This test, despite of having a fast response time, may lead to human errors, which sometimes can be fatal to the patient. This paper presents the development of an automatic mechatronic prototype for determining human blood typing (ABO and Rh systems) through image processing techniques. The prototype design takes into account the characteristics of reliability of analysis, portability, and response time allowing the system to be used in emergency situations. The developed prototype performs blood and reagents mixture acquires the resultant image and processes the data (based on image processing techniques) to determine the sample blood type. It was tested in a laboratory, using cataloged samples of blood types, provided by the Portuguese Institute of Blood and Transplantation. Hereafter, it is expected to test and validate the prototype in clinical environments.

Blood lipid associations in 18 year-old men

The association of cigarette smoking, physical activity at work, and social class with total cholesterol and with high and low density lipoprotein cholesterol were examined in a random sample of 238 males, of 18 years of age, of Rosario, Argerntina. The mean (mg/dl) total serum cholesterol of the whole sample was 174.7, the high density lipoprotein cholesterol 52.8, and the low density lipoprotein cholesterol 121.5. Black tobacco consumers, evenly distributed by social class, had higher levels of total and low density lipoprotein cholesterol. Total cholesterol was higher in the high social class, differently from what smokers' distribution by social class, would lead one to expect. While a highly negative association was found between social class and physical activity at work, there were no significant diferences in lipoprotein levels between manual and non-manual workers. It is possible that the nutritional differences by social class still prevail over the smoking habit in their influence on the lipoprotein levels in these subjects.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 1- Parity of blood seeking Anopheles (Kerteszia) in South-Eastern Brazil

Populations of Anopheles (Kerteszia) were sampled fortnightly over a one-year period (August 1991 to July 1992) at Ribeira Valley, S. Paulo State, Brazil. Indoor and outdoor collections were made on human bait at evening crepuscular period. The Polovodova technique for age grading was applied to 3,501 females of Anopheles cruzii and to 416 females of An. bellator. That sample represented 34.4% of the total number of mosquitoes collected. The most abundant species found was An. cruzii. However, An. bellator showed an endophagy that was almost three times greater than that of An. cruzii. The overall parous rate was 25.4% and uniparity was practically dominant one. A proportion of 26.9% of An. cruzii and 12.0% of An. bellator were found to be uniparous. Only three outdoor females of the former species (0.1%) showed biparity. Parity of An. cruzii was higher in females caught outdoors than in those caught indoors. Nevertheless, 497 nulliparous females examined (417 cruzii and 80 bellator) had ovaries that had advanced to Christophers and Mer stages III to V. These results imply that these females had already practised hematophagy. Relating these results to those from the parous females, a high statistical significance was found, leading to the conclusion that gonothophic discordance is a common pattern among these anophelines. Further, these results obtained with human bait catches strongly suggest that nearly 38.0% of these host-seeking females had already taken at least one previous blood-meal. So it is possible that enough time could thus be available for the plasmodian development in the vectors.

Micronuclei in peripheral blood lymphocytes in formaldehyde occupationally exposed workers

Formaldehyde (CH2O) the most simple and reactive of all aldehydes, is a colorless, reactive and readily polymerizing gas at normal temperature. It has a pungent, suffocating odour that is recognized by most human subjects at concentrations below 1 ppm. According to the Report on Carcinogens, formaldehyde (FA) ranks 25th in the overall U.S. chemical production with more than 11 billion pounds (5 million tons) produced each year. Is an important industrial compound that is used in the manufacture of synthetic resins and chemical compounds such as lubricants and adhesives. It has also applications as a disinfectant, preservative and is used in cosmetics. Estimates of the number of persons who are occupationally exposed to FA indicate that, at least at low levels, may occur in a wide variety of industries. The occupational settings with most extensive use of formaldehyde is in the production of resins and in anatomy and pathology laboratories. Several studies reported a carcinogenic effect in humans after inhalation of FA, in particular an increased risk for nasopharyngeal cancer. Nowadays, the International Agency for Research on Cancer (IARC) classifies FA as carcinogenic to humans (group 1), on the basis of sufficient evidence in humans and sufficient evidence in experimental animals. Manifold in vitro studies clearly indicated that FA is genotoxic. FA induced various genotoxic effects in proliferatin cultured mammalian cells. A variety of evidence suggests that the primary DNA alterations after FA exposure are DNA-protein crosslinks (DPX). Incomplete repair of DPX can lead to the formation of mutations.

Human case of gastric infection by a fourth larval stage of Pseudoterranova decipiens (Nematoda, Anisakidae)

Only three cases of human infection by anisakid nematodes have been reported in Chile since 1976. In the present case, an anisakid worm, identified as a fourth-stage Pseudoterranova decipiens larva, was removed with a gastroendoscopic biopsy clipper from the stomach of a 45 year-old man from southern Chile. The patient, who presented acute epigastric pain and a continuous sensation of having an empty stomach, reported having eaten smoked fish. The worm was fixed in 70% ethanol and cleaned in lactophenol for morphological study. The morphometric characteristics of the worm are described and drawn. Anisakid larvae in fish flesh can be killed by freezing or cooking.

Evaluation and additional recommendations for preparing a whole blood control material

OBJECTIVE: The assessment of an easy to prepare and low cost control material for Hematology, available for manual and automated methods. MATERIAL AND METHOD: Aliquots of stabilized whole blood were prepared by partial fixation with aldehydes; the stability at different temperatures (4. 20 and 37 °C) during periods of up to 8-9 weeks and aliquot variability with both methods were controlled. RESULTS: Aliquot variability with automated methods at day 1, expressed as CV% (coefficient of variation) was: white blood cells (WBC) 2.7, red blood cells (RBC) 0.7, hemoglobin (Hb) 0.6, hematocrit (Hct) 0.7, mean cell volume (MCV) 0.3, mean cell hemoglobin (MCH) 0.6, mean cell hemoglobin concentration (MCHC) 0.7, and platelets (PLT) 4.6. The CV (coefficient of variation) percentages obtained with manual methods in one of the batches were: WBC 23, Hct 2.8, Hb 4.5, MCHC 5.9, PLT 41. Samples stored at 4ºC and 20ºC showed good stability, only a very low initial hemolysis being observed, whereas those stored at 37ºC deteriobed a rapidly (metahemoglobin formation, aggregation of WBC and platelets, as well as alteration of erythrocyte indexes). CONCLUSIONS: It was confirmed that, as long as there is no exposure to high temperatures during distribution, this material is stable, allowing assessment, both esternal and internal, for control purposes, with acceptable reproductivity, both for manual and auttomatic methods.

Multi-stage evolution of a sub-aerial volcanic ridge over the last 1.3 Myr: S. Jorge Island, Azores Triple Junction

New K/Ar dating and geochemical analyses have been carried out on the WNW-ESE elongated oceanic island of S. Jorge to reconstruct the volcanic evolution of a linear ridge developed close to the Azores triple junction. We show that S. Jorge sub-aerial construction encompasses the last 1.3 Myr, a time interval far much longer than previously reported. The early development of the ridge involved a sub-aerial building phase exposed in the southeast end of the island and now constrained between 1.32 +/- 0.02 and 1.21 +/- 0.02 Ma. Basic lavas from this older stage are alkaline and enriched in incompatible elements, reflecting partial melting of an enriched mantle source. At least three differentiation cycles from alkaline basalts to mugearites are documented within this stage. The successive episodes of magma rising, storage and evolution suggest an intermittent reopening of the magma feeding system, possibly due to recurrent tensional or trans-tensional tectonic events. Present data show a gap in sub-aerial volcanism before a second main ongoing building phase starting at about 750 ka. Sub-aerial construction of the S. Jorge ridge migrated progressively towards the west, but involved several overlapping volcanic episodes constrained along the main WNW-ESE structural axis of the island. Malic magmas erupted during the second phase have been also generated by partial melting of an enriched mantle source. Trace element data suggest, however, variable and lower degrees of partial melting of a shallower mantle domain, which is interpreted as an increasing control of lithospheric deformation on the genesis and extraction of primitive melts during the last 750 kyr. The multi-stage development of the S. Jorge volcanic ridge over the last 1.3 Myr has most likely been greatly influenced by regional tectonics, controlled by deformation along the diffuse boundary between the Nubian and the Eurasian plates, and the increasing effect of sea-floor spreading at the Mid-Atlantic Ridge.

Modelling of n-stage Blumlein stacked lines for bipolar pulse generation

A Blumlein line is a particular Pulse Forming Line, PFL, configuration that allows the generation of high-voltage sub-microsecond square pulses, with the same voltage amplitude as the dc charging voltage, into a matching load. By stacking n Blumlein lines one can multiply in theory by n the input dc voltage charging amplitude. In order to understand the operating behavior of this electromagnetic system and to further optimize its operation it is fundamental to theoretically model it, that is to calculate the voltage amplitudes at each circuit point and the time instant that happens. In order to do this, one needs to define the reflection and transmission coefficients where impedance discontinuity occurs. The experimental results of a fast solid-state switch, which discharges a three stage Blumlein stack, will be compared with theoretical ones.

Photonics Active Filters Based on SiC Multi layer Structures: A Two Stage Active Circuit

Characteristics of tunable wavelength filters based on a-SiC:H multi-layered stacked cells are studied both theoretically and experimentally. Results show that the light-activated photonic device combines the demultiplexing operation with the simultaneous photodetection and self amplification of an optical signal. The sensor is a bias wavelength current-controlled device that make use of changes in the wavelength of the background to control the power delivered to the load, acting a photonic active filter. Its gain depends on the background wavelength that controls the electrical field profile across the device.

Linfangiogénese no tecido adiposo em modelos de doença inflamatória crónica (asma e obesidade): uma abordagem por imunohistoquímica e lipidómica

O tecido adiposo é um órgão endócrino dinâmico, secretando factores importantes na regulação do metabolismo, fluxo vascular sanguíneo e linfático, e função imunológica, entre outros. Em caso de acumulação de tecido adiposo por ingestão de uma dieta gorda, ou por disfunção metabólica, os adipócitos podem desencadear uma reacção inflamatória por falha na drenagem linfática, acumulando-se mediadores inflamatórios, os quais potenciam a propagação da reacção. Assim, questiona-se uma potencial associação entre o aumento de tecido adiposo na obesidade, hipóxia adipocitária e estimulação da linfangiogénese. Além disso, a expressão de adipocinas varia de acordo com a distribuição do tecido adiposo (subcutâneo, TAS e visceral, TAV). Deste modo, pretende-se com este estudo contribuir para o aumento do conhecimento sobre os complexos mecanismos moleculares subjacentes à linfangiogénese. Ensaios com ratinhos da estirpe C57Bl/6J (modelo de obesidade) e BALB/c (modelo de asma e obesidade), divididos em grupos submetidos a dieta normal e dieta rica em gordura. Avaliação semi-quantitativa da expressão tecidular de LYVE-1 (marcador da linfangiogénese) por imunohistoquímica em material embebido em parafina, no TAS e TAV, e cromatografia líquida de ultra-performance acoplada de espectrometria de massa (UPLC-MS) para análise da expressão plasmática de ceramida e esfingosina-1-fosfato (S1P). No modelo de obesidade observou- -se diminuição do número de vasos linfáticos e expressão de LYVE-1 ao longo do tempo no TAV, e aumento de ambos os parâmetros e hipertrofia adipocitária no TAS. As concentrações de ceramida e S1P corroboram a existência de um processo inflamatório nos ratinhos em estudo, ainda que numa fase muito inicial. No modelo de asma e obesidade, após 17 semanas de tratamento, observou-se incremento da linfangiogénese no TAV, mas não no TAS. A resposta inflamatória avaliada através dos diferentes parâmetros permite afirmar que num estadio inicial de obesidade a proliferação linfática poderá estar a ser retardada pela hipertrofia adipocitária. A libertação de adipocinas será observada apenas numa fase posterior, desencadeando todo o processo inflamatório que incrementará a proliferação linfática. Adicionalmente, é possível sugerir que a maior pressão à qual o TAV se encontra sujeito não favorece a proliferação linfática, pelo menos num estadio incial.

HTLV-I/II and blood donors: determinants associated with seropositivity in a low risk population

OBJECTIVE: Blood donors in Brazil have been routinely screened for HTLV-I/II since 1993. A study was performed to estimate the prevalence of HTLV-I/II infection in a low risk population and to better understand determinants associated with seropositivity. METHODS: HTLV-I/II seropositive (n=135), indeterminate (n=167) and seronegative blood donors (n=116) were enrolled in an open prevalence prospective cohort study. A cross-sectional epidemiological study of positive, indeterminate and seronegative HTLV-I/II subjects was conducted to assess behavioral and environmental risk factors for seropositivity. HTLV-I/II serological status was confirmed using enzyme-linked immunosorbent assay (EIA) and Western blot (WB). RESULTS: The three groups were not homogeneous. HTLV-I/II seropositivity was associated to past blood transfusion and years of schooling, a marker of socioeconomic status, and use of non-intravenous illegal drugs. CONCLUSIONS: The study results reinforce the importance of continuous monitoring and improvement of blood donor selection process.

Trypanosoma cruzi prevalence and clinical forms in blood donor candidates in Brazil

The prevalence and clinical forms of Trypanosoma cruzi were evaluated among blood donor candidates attended at a general hospital in Rio de Janeiro, Brazil, from January 1997 to April 1999. The investigation was done by means of the indirect hemagglutination test and was confirmed via ELISA. Data were collected from clinical examinations, conventional electrocardiogram, chest radiography and echocar-diography. The results showed that despite Trypanosoma cruzi prevalence of 1.17% (128 patients), mainly in males aged 40 years or over, 70.8% of these patients, mainly males aged 19 to 39 years, demonstrated abnormalities that allowed the diagnosis of cardiopathy and/or esophagopathy. This once again corroborates the importance of Trypanosoma cruzi infection in urban centers.