Optimization of immunocytochemistry in cytology: comparison of two protocols for fixation and preservation on cytospin and smear preparations

Objective: A new protocol for fixation and slide preservation was evaluated in order to improve the quality of immunocytochemical reactions on cytology slides. Methods: The quality of immunoreactions was evaluated retrospectively on 186 cytology slides (130 direct smears, 56 cytospins) prepared from different cytology samples. Ninety-three of the slides were air dried, stored at -20 °C and fixed in acetone for 10 minutes (Protocol 1), whereas the other 93 were immediately fixed in methanol at -20 °C for at least 30 minutes, subsequently protected with polyethylene glycol (PEG) and stored at room temperature (Protocol 2). Immunocytochemical staining, with eight primary antibodies, was performed on a Ventana BenchMark Ultra instrument using an UltraView Universal DAB Detection Kit. The following parameters were evaluated for each immunoreaction: morphology preservation, intensity of specific staining, background and counterstain. The slides were blinded and independently scored by four observers with marks from 0 to 20. Results: The quality of immunoreactions was better on methanol-fixed slides protected with PEG than on air-dried slides stored in the freezer: X¯ = 14.44 ± 3.58 versus X¯ = 11.02 ± 3.86, respectively (P < 0.001). Conclusion: Immediate fixation of cytology slides in cold methanol with subsequent application of PEG is an easy and straightforward procedure that improves the quality of immunocytochemical reactions and allows the storage of the slides at room temperature.

Identification of Paracoccidioides brasiliensis in adrenal glands biopsies of two patients with paracoccidioidomycosis and adrenal insufficiency

The authors report two cases of adrenal insufficiency secondary to infiltration of the adrenal glands by Paracoccidioides brasiliensis. The first patient had been treated for a chronic multifocal form of paracoccidiodomycosis 11 years ago. The diagnosis of the mycosis was done simultaneous with that of the adrenal insufficiency in the second patient. In both patients the diagnosis was done by direct visualization of fungus in adrenal biopsies. They were treated with hormonal supplements and itraconazol by 12 and six months, without relapses during the follow-up period.

Robot Manipulator Systems: Analysis and Control

Manipulator systems are rather complex and highly nonlinear which makes difficult their analysis and control. Classic system theory is veil known, however it is inadequate in the presence of strong nonlinear dynamics. Nonlinear controllers produce good results [1] and work has been done e. g. relating the manipulator nonlinear dynamics with frequency response [2–5]. Nevertheless, given the complexity of the problem, systematic methods which permit to draw conclusions about stability, imperfect modelling effects, compensation requirements, etc. are still lacking. In section 2 we start by analysing the variation of the poles and zeros of the descriptive transfer functions of a robot manipulator in order to motivate the development of more robust (and computationally efficient) control algorithms. Based on this analysis a new multirate controller which is an improvement of the well known “computed torque controller” [6] is announced in section 3. Some research in this area was done by Neuman [7,8] showing tbat better robustness is possible if the basic controller structure is modified. The present study stems from those ideas, and attempts to give a systematic treatment, which results in easy to use standard engineering tools. Finally, in section 4 conclusions are presented.

Epidemiological studies of Streptococcus pneumoniae carriage in the post-vaccination era among two risk groups: children and the elderly

Dissertation presented to obtain the Ph.D. degree in Biology/ Molecular Biology

Microelectromechanical systems. Fabrication and characterization of microcantilevers

Microelectromechanical systems (MEMS) technologies can be used to produce from the simplest structures to the most complex devices and systems. Due to their many applications in various fields, MEMS have turned into one of the most researched areas in microtechnology. In this context, this project was developed in an attempt to produce one of most used structures in MEMS sensing devices - microcantilevers. Several microfabrication techniques were combined to fabricate this type of structures on the top layer of silicon of a silicon-on-insulator (SOI) wafer. After the microcantilevers had been successfully created, an experiment was set up to verify the microcantilevers ability to bend. Here, a voltage was applied between the top and bottom layers of silicon of the SOI wafer. It was then observed that the microcantilevers were deflected all the way to the bottom silicon layer by the electrostatic force acting between them, given that a current was detected when a certain value of applied voltage was reached.

Antimicrobial activity of honeys from two stingless honeybee species and Apis mellifera (Hymenoptera: Apidae) against pathogenic microorganisms

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.

Introducing resistance genes against ToMV, TYLCV and TSWV infections in two tomato varieties (Muchamiel and De la Pera)

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas

Dinámica Cuántica de Sistemas Complejos: Fundamentos y Aplicaciones. Quantum Dynamics in Complex Systems: Fundamentals and Aplications.

El procedimiento de revertir la dinámica colectiva (diablillo de Loschmidt apresurado) mediante un pulso de radio frecuencia, permite generar un Eco de Loschmidt, es decir la refocalización de una excitación localizada. Alternativamente, en acústica es posible implementar un Espejo de Reversión Temporal, que consiste en la progresiva inyección de una débil excitación ultrasónica en la periferia de un sistema, para construir una excitación que se propaga "hacia atrás". Así, podemos afirmar que es posible revertir y controlar la dinámica. Sin embargo, aún no se posee una comprensión detallada de los mecanismos que gobiernan estos procedimientos. Este proyecto busca responder las preguntas que posibilitan esta comprensión.

Compared nymphal development of Tingis americana (Hemiptera, Tingidae) in two Handroanthus species (Bignoniaceae) and reproductive parameters in seedlings of Handroanthus heptaphyllus

Nymphs and adults of Tingis americana Drake, 1922 were found feeding on leaves of Handroanthus heptaphyllus (Vell.) Mattos and Handroanthus chrysotrichus (Mart. ex A. DC.) Mattos in the Botanic Garden, Porto Alegre, state of Rio Grande do Sul, Brazil. This is the first record of T. americana on these host plants and in the southern Brazil. We aimed to compare the nymphal development on both hosts and to analyze the reproductive parameters on H. heptaphyllus (25 ± 1ºC; 60 ± 10% RH; 16 h photophase). The mean nymphal period (days) was shorter in individuals reared on H. heptaphyllus (12.69 ± 0.076) than on H. chrysotrichus (19.11 ± 0.208) (P < 0.0001), however, nymph viability was similar. On H. heptaphyllus, the mean embryonic period lasted 12.32 ± 0.274 days and the egg viability was 92%. The mean total and daily fecundity were 310.0 ± 19.40 eggs/female and 7.46 ± 0.302 eggs/female/day, respectively. Paired males and females showed similar longevity (P = 0.0691), while unpaired females lived longer than unpaired males (P = 0.0460).

Bifurcations of homoclinic tangency in two-dimensional area-preserving and reversible maps

Report for the scientific sojourn at the Research Institute for Applied Mathematics and Cybernetics, Nizhny Novgorod, Russia, from July to September 2006. Within the project, bifurcations of orbit behavior in area-preserving and reversible maps with a homoclinic tangency were studied. Finitely smooth normal forms for such maps near saddle fixed points were constructed and it was shown that they coincide in the main order with the analytical Birkhoff-Moser normal form. Bifurcations of single-round periodic orbits for two-dimensional symplectic maps close to a map with a quadratic homoclinic tangency were studied. The existence of one- and two-parameter cascades of elliptic periodic orbits was proved.

Evolution of holometabola insect digestive systems: physiological and biochemical aspects

This review takes into account primarily the work done in our laboratory with insects from the major Holometabola orders. Only the most significant data for each insect will be presented and a proposal on the evolution of Holometabola insect digstive systems will be advanced.

On two examples by Iyama and Yoshino

In a recent paper Iyama and Yoshino consider two interesting examples of isolated singularities over which it is possible to classify the indecomposable maximal Cohen-Macaulay modules in terms of linear algebra data. In this paper we present two new approaches to these examples. In the first approach we give a relation with cluster categories. In the second approach we use Orlov's result on the graded singularity category. We obtain some new results on the singularity category of isolated singularities which may be interesting in their own right.