Immunogenicity test of tetanus component in adsorbed vaccines by toxin binding inhibition test

Samples from 20 lots of diphtheria-tetanus (adult use dT) vaccine and from 20 lots of diphtheria-tetanus-pertussis (DTP) vaccine were used to standardize and validate the in vitro toxin binding inhibition (ToBI) test for the immunogenicity test of the tetanus component. The levels of tetanus antitoxin obtained by ToBI test were compared to those obtained using the toxin neutralization (TN) test in mice routinely employed to perform the quality control of the tetanus component in adsorbed vaccines. The results ranged from 1.8 to 3.5 IU/ml for dT and 2 to 4 IU/ml for DTP by ToBI test and 1.4 to 3 IU/ml for dT and 1.8 to 3.5 IU/ml for DTP by TN in mice. These results were significantly correlated. From this study, it is concluded that the ToBI test is an alternative to the in vivo neutralization procedure in the immunogenicity test of the tetanus component in adsorbed vaccines. A substantial refinement and a reduction in use of animals can be achieved.

Antiretroviral resistance mutations in human immunodeficiency virus type 1 infected patients enrolled in genotype testing at the Central Public Health Laboratory, São Paulo, Brazil: preliminary results

Antiretroviral resistance mutations (ARM) are one of the major obstacles for pharmacological human immunodeficiency virus (HIV) suppression. Plasma HIV-1 RNA from 306 patients on antiretroviral therapy with virological failure was analyzed, most of them (60%) exposed to three or more regimens, and 28% of them have started therapy before 1997. The most common regimens in use at the time of genotype testing were AZT/3TC/nelfinavir, 3TC/D4T/nelfinavir and AZT/3TC/efavirenz. The majority of ARM occurred at protease (PR) gene at residue L90 (41%) and V82 (25%); at reverse transcriptase (RT) gene, mutations at residue M184 (V/I) were observed in 64%. One or more thymidine analogue mutations were detected in 73%. The number of ARM at PR gene increased from a mean of four mutations per patient who showed virological failure at the first ARV regimens to six mutations per patient exposed to six or more regimens; similar trend in RT was also observed. No differences in ARM at principal codon to the three drug classes for HIV-1 clades B or F were observed, but some polymorphisms in secondary codons showed significant differences. Strategies to improve the cost effectiveness of drug therapy and to optimize the sequencing and the rescue therapy are the major health priorities.

Pharmacotherapy and analysis of gaseous mediators in hypertensive patients

OBJECTIVE To evaluate the effect of using antihypertensive classes of drugs of the calcium channel antagonists and inhibitors of angiotensin-converting enzyme in plasma concentrations of hydrogen sulfide and nitric oxide in patients with hypertension. METHODS Cross-sectional study with quantitative approach conducted with hypertensive patients in use of antihypertensive classes of drugs: angiotensin-converting enzyme inhibitors or calcium channel antagonists. RESULTS It was found that the concentration of plasma nitric oxide was significantly higher in hypertensive patients that were in use of angiotensin-converting enzyme inhibitors (p<0.03) and the hydrogen sulphide concentration was significantly higher in hypertensive plasma in use of calcium channel antagonists (p<0.002). CONCLUSION The findings suggest that these medications have as additional action mechanism the improvement of endothelial dysfunction by elevate plasma levels of vasodilatory substances.

Glyphosate behavior in a Rhodic Oxisol under no-till and conventional agricultural systems

The behavior of glyphosate in a Rhodic Oxisol, collected from fields under no-till and conventional management systems in Ponta Grossa, Parana state (Brazil) was investigated. Both agricultural systems had been in production for 23 years. Glyphosate mineralization, soil-bound forms, sorption and desorption kinetics, sorption/desorption batch experiments, and soil glyphosate phythoavailability (to Panicum maximum) were determined. The mineralization experiment was set up in a completely randomized design with a 2 x 2 factorial scheme (two management systems and two 14C radiolabelled positions in the glyphosate), with five replicates. 14CO2 evolution was measured in 7-day intervals during 63 days. The glyphosate sorption kinetics was investigated in a batch experiment, employing a glyphosate concentration of 0.84 mg L-1. The equilibration solution was 0.01 mol L-1 CaCl2 and the equilibration times were 0, 10, 30, 60, 120, 240, and 360 min. Sorption/desorption of glyphosate was also investigated using equilibrium batch experiments. Five different concentrations of the herbicide were used for sorption (0.42, 0.84, 1.68, 3.36, and 6.72 mg L-1) and one concentration for desorption. Glyphosate phytoavailability was analyzed in a 2 x 5 factorial scheme with two management systems and five glyphosate concentrations added to soil (0, 4.2, 8.4, 42.0, and 210.0 µg g-1) in a completely randomized design. Phytotoxicity symptoms in P. maximum were evaluated for different periods. The soil under both management systems showed high glyphosate sorption, which impeded its desorption and impaired the mineralization in the soil solution. Practically the total amount of the applied glyphosate was quickly sorbed (over 90 % sorbed within 10 min). Glyphosate bound to residues did not have adverse effects on P. maximum growth. The mineralization of glyphosate was faster under no-till and aminomethylphosphonic acid was the main glyphosate metabolite.

Nitrogen dynamics in soil management systems: II - mineralization and nitrification rates

Nitrogen is the main limiting factor in crop productivity and thereby soil management systems may change the mineralization and nitrification rates. In an experiment on soil management systems implemented in 1988 at the experimental station Fundação ABC, Ponta Grossa, in the central South region of the State of Paraná, inorganic N dynamics were examined to find a soil management strategy with a view to a sustainable environment. The objective of this study was to calculate the net mineralization and nitrification rates of soil N and the correlation with soil pH under management systems. Randomized complete block design was used, in split plots, in three replications. The following soil management systems (SMSs) were adopted in the plots: 1) conventional tillage (CT); 2) minimum tillage (MT); 3) no-tillage with chisel plow every three years (NT CH); and 4) continuous no-tillage (CNT). To evaluate the dynamics of inorganic N, samples were collected from sub-plots at different times (11 sampling times - T1 to T11). In the CNT and NT CH, the net mineralization rates were higher in the MT and CT systems in the 0-2.5 cm soil layer, while the nitrification rate was higher in the 2.5-5 cm layer. Soon after implementing the white oat management, the mineralization and nitrification rates in all soil layers were higher in the MT and CT systems. In the period of soybean development, in the 0-2.5 and 2.5-5 cm soil layers, the mineralization and nitrification rates were higher in the CNT and NT CH than in the MT and CT systems.

Cover plants and mineral nitrogen: effects on organic matter fractions in an oxisol under no-tillage in the cerrado

Cover plants are essential for the sustainability of no-tillage systems in tropical regions. However, information on the effects of these plants and N fertilization on soil organic matter fractions is still scarce. This study evaluated the effect of cover crops with different chemical composition and of N topdressing on the labile and humified organic matter fractions of an Oxisol of the Cerrado (savanna-like vegetation). The study in a randomized complete block design was arranged in split-plots with three replications. Four cover species were tested in the plots and the presence or absence of N topdressing in the subplot. The following cover species were planted in succession to corn for eight years: Urochloa ruziziensis; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L.) Millsp; and Sorghum bicolor (L.) Moench. In general, the cultivation of U. ruziziensis increased soil C levels, particularly of C in the humic acid and particulate organic C fractions, which are quality indicators of soil organic matter. The C in humic substances and mineral organic C accounted for the highest proportions of total organic C, demonstrating the strong interaction between organic matter, Fe and Al oxides and kaolinite, which are predominant in these weathered soils of the Cerrado.

Characterization of the effects of macronutrient deficiencies in mangabeira seedlings

Knowledge of the mineral nutrition requirements of mangabeira (Hancornia speciosa Gomes) is relatively scarce and rudimentary because there is a lack of consistent data concerning its nutritional demands at different developmental stages. The aim of this research was to characterize the visual symptoms of macronutrient deficiencies and to evaluate the effects of these deficiencies on the growth, the production of dry matter, and the leaf content of mangabeira. To achieve this goal, a greenhouse experiment was conducted at the Goiano Federal Institute (Instituto Federal Goiano) in Rio Verde - GO, from January to June 2011 in which mangabeira plants were arranged in a random block design and grown in nutrient solutions. This experiment was replicated four times. The plants were treated with either a complete nutrient solution or a nutrient solution from which the individual macronutrient of interest (nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca), or sulfur (S) had been omitted. The omission of a macronutrient from the nutrient solution resulted in morphological alterations that were characteristic symptoms of the particular nutritional deficiency and caused decreases in growth and dry matter mass production. The accumulation of macronutrients displayed the following order in mangabeira leaves: N>K>Ca>P>S>Mg.

Sistema de alimentação gás-líquido para medidas de atividade catalítica

This note has as objective to present the advantages of the use of syringe-type pumps for the feeding of liquid reactants, together with mass flow controllers for gases, instead of the saturators, as it is generally accomplished. Among the advantages, the system with syringe pumps presents a greater flexibility in flow control as well as in composition compared with the system that uses saturator. In addition, the flow of the liquid reactants is known with precision in the syringe pump system.

Do termoscópio ao termômetro digital: quatro séculos de termometria

This work describes the evolution of temperature measurement in the last four centuries using thermometers based on the thermal expansion of liquids such as ethyl alcohol and mercury. The concept of temperature was strongly dependent on the researcher and there was no systematic temperature scale for universal use. The precursor of the common thermometer was the thermoscope, probably invented at the end of the XVIth century. In the XVIIIth century the instrument was greatly improved and several thermometric scales were proposed some of which have been in use until now. These scales were based on arbitrary points. Mercury and ethyl alcohol were the most employed thermometric fluids. In the XIXth century, the concept of absolute zero was a great advance in this field. The most important contribution during the XXth century was the establishment of international temperature scales. The design of the thermometer has been essentially the same along the last 300 years, but many models were proposed for industrial and research purposes. Its association with the densimeter was of great importance for control of industrial chemical processes and also for teaching purposes in the past. Nowadays, there is a clear tendency to replace mercury-based thermometers by electronic digital models. Thermochemistry is the natural relationship between temperature and chemistry.

Designing and manufacturing of a soybean harvest residue picker

ABSTRACT Soy harvest matches seasons with shortage of dry matter supply for ruminant feeding in most Brazilian soy-growing areas. Agricultural machinery-producing companies must have market perception, observing new opportunities and developing equipment to meet costumers’ needs. This paper aims to design, build, and test a device to collect soybean crop residues from the combine cleaning mechanism, consisting mainly of vegetable straw (chaff), and the other plant parts (stems) remain being deposited onto the ground. For equipment designing, we made use of the architectural design methodology proposed in the reference model for the agricultural machinery development process. The equipment was designed and built following the proposed methodology, then installed and put into operation in a John Deere 1165 combine. After initial testing and few adjustments, the device showed satisfactory chaff-collecting performance. The equipment consists of a screw conveyor assembled transversely to the combine and a centrifugal fan assembled on the side. The collected chaff is dumped into a trailer towed by tractor.

Adherence to drug therapy in kidney disease

Non-adherence to drug therapy has not been extensively studied in patients with chronic kidney disease (CKD). The objective of the present study was to identify determinants of non-adherence to drug therapy in patients with CKD, not on dialysis. A prospective cohort study involving 149 patients was conducted over a period of 12 months. Adherence to drug therapy was evaluated by the self-report method at baseline and at 12 months. Patients who knew the type of drug(s) and the respective number of prescribed pills in use at the visit preceding the interview were considered to be adherent. Patients with cognitive decline were assessed by interviewing their caregivers. Mean patient age was 51 ± 16.7 years. Male patients predominated (60.4%). Univariate analysis performed at baseline showed that non-adherence was associated with older age, more pills taken per day, worse renal function, presence of coronary artery disease, and reliance on caregivers for the administration of their medications. In multivariate analysis, the factors that were significantly associated with non-adherence were daily use of more than 5 pills and drug administration by a caregiver. Longitudinal evaluation showed an increase in non-adherence over time. Medication non-adherence was lower (17.4%) at the baseline period of the study than after 1 year of the study (26.8%). Compared to the baseline period, the percentage of adherent patients who became non-adherent (22%) was lower than the percentage of non-adherent patients who became adherent (50%). In CKD patients not on dialysis, non-adherence was significantly associated with the number of pills taken per day and drug administration by third parties. Adherence is more frequent than non-adherence over time.

Challenges in the research and development of new human vaccines

The field of vaccinology was born from the observations by the fathers of vaccination, Edward Jenner and Louis Pasteur, that a permanent, positive change in the way our bodies respond to life-threatening infectious diseases can be obtained by specific challenge with the inactivated infectious agent performed in a controlled manner, avoiding the development of clinical disease upon exposure to the virulent pathogen. Many of the vaccines still in use today were developed on an empirical basis, essentially following the paradigm established by Pasteur, “isolate, inactivate, and inject” the disease-causing microorganism, and are capable of eliciting uniform, long-term immune memory responses that constitute the key to their proven efficacy. However, vaccines for pathogens considered as priority targets of public health concern are still lacking. The literature tends to focus more often on vaccine research problems associated with specific pathogens, but it is increasingly clear that there are common bottlenecks in vaccine research, which need to be solved in order to advance the development of the field as a whole. As part of a group of articles, the objective of the present report is to pinpoint these bottlenecks, exploring the literature for common problems and solutions in vaccine research applied to different situations. Our goal is to stimulate brainstorming among specialists of different fields related to vaccine research and development. Here, we briefly summarize the topics we intend to deal with in this discussion.