Search

Copyright of Jornal Brasileiro de Patologia e Medicina Laboratorial is the property of Sociedade Brasileira de Patologia Clinica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The spermathecae of Heteroptera exhibit great morphological variety. The characteristics of spermathecal morphology may contribute greatly toward the taxonomy and reproductive physiology of these insects. This study describes the spermathecal morphology of the agricultural pest, Leptoglossus zonatus (Dallas). The spermatheca of L. zonatus is distinguishable into three parts--the reservoir (distal portion), muscular duct (middle region), and enlarged duct (proximal end). The spherical reservoir has a cuticle-lined lumen, followed by a layer of flattened cells, below which lies another layer of cells with secretory characteristics. The muscular duct is characterized by a flange where the insertion of the muscle fibers is seen. The proximal duct is enlarged with a compartmentalized lumen. The morphological features of the spermatheca of L. zonatus differ from those described for other Heteroptera. [ABSTRACT FROM AUTHOR]

This paper focuses on the development of a proximate time optimal control method for two-dimensional rigid body systems, eg. XY positioning tables. Our approach is based on the traditional proximate time-optimal servomechanism (PTOS), which starts with a near-time-optimal non-linear controller and then switches to a linear controller as the system output approaches the desired target. This work proposes to expand the PTOS, a unidirectional control law to twodimensional systems, in order to perform linear point to point trajectories in minimum time. [ABSTRACT FROM AUTHOR]

Caste determination inTrigona spinipesFabricius (Hymenoptera, Apidae, Meliponini) is trophogenic. Larvae that eat about 360 μl of food become queens, while those who consume 36 μl develop into workers. We studied the effect of larval nutrition on the number and length of ovarioles and on ovarian development in fifth instar larvae, white eyed, pink eyed and black-eyed pupae as well as newly emerged adults. All larvae have four ovarioles per ovary, while in queen pupae this number ranged from 8 to 15. Cyst formation, the cell death and other characteristics of ovary morphogenesis were the same regardless of the quantity of food consumed. These results are discussed in relation to caste differentiation in other bees. [ABSTRACT FROM AUTHOR]

The development of culture systems to support the initiation of growth of primordial follicles is important to the study of the factors that control the earliest stages of folliculogenesis. The aims of the present study were to investigate the effects of α-tocopherol on survival, activation, and growth of cattle preantral follicles using histological and immunohistochemistry proliferating cell nuclear antigen (PCNA) studies. The ovarian cortex was divided into small fragments; one fragment was immediately fixed in Bouin (control). The other fragments were cultured for 2, 4, 6, or 8 d in culture plates with Minimum Essential Medium supplemented with insulin-transferrin-selenium (ITS), pyruvate, glutamine, hypoxanthine, BSA, and antibiotics (MEM+); and MEM+ plus α-tocopherol (5, 25, 50, 100, or 200 ng mL-1). Preantral follicles were classified according to their developmental stage (primordial, intermediate, primary, or secondary) and on the basis of morphological features (normal or degenerated). Pair-wise comparisons were done using Tukey''s procedure. Chi-square test was used to compare the percentage of follicles with PCNA-positive granulosa cells. All analyses were done with the SAS software (SAS Institute, Cary, NC, USA), and P< 0.05 was considered significant. The results showed that, compared with non-cultured cortical tissue (Day 0), the culture of ovarian tissue significantly reduced (P< 0.05) the percentage of normal follicles in all media tested, except for tissue cultured in the presence of 200 ng mL-1of a-tocopherol. Furthermore, in all media tested, the percentage of primordial follicles was significantly reduced (P< 0.05), with a concomitant increase in the percentage of developing follicles. The highest percentage of secondary follicles was observed after 6 days of culture in MEM plus 200 ng mL-1of a-tocopherol. The PCNA analysis confirmed the viability of follicles cultured with 200 ng mL-1of a-tocopherol after 6 d. After 8 days of in vitroculture, we observed severe follicular degeneration in all media tested, suggesting that other supplements are recommended for longer periods of culture. In conclusion, the results of the present study indicate that 200 ng mL-1of a-tocopherol maintains the survival of cattle preantral follicles and promotes activation of primordial follicles after 6 days of in vitroculture. Financial support: L. A. Lisboa is a recipient of CAPES support; E. R. Andrade and A. A. Alfieri are recipients of PRODOC/CAPES fellowships. [ABSTRACT FROM AUTHOR]

An abstract of the article "Intraoperative model to flowmetry measurement from coronary-coronary saphenous vein graft bypass" by L. A. Dallan and colleagues is presented.

An abstract of the article "EuroSCORE II and the importance of a local model, InsCor" by L. Lisboa and colleagues is presented.

The mechanisms that regulate the gradual exit of ovarian follicles from the nongrowing, primordial pool are poorly understood. The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitroculture of cattle ovarian fragments and to determine the effects of this addition on the growth activation and viability of preantral follicles. The ovarian cortex was divided into small fragments; 1 fragment was immediately fixed in Bouin''s solution (control). The other fragments were cultured for 2, 4, 6, or 8 days on culture plates in minimum essential medium (MEM) supplemented with insulin-transferrin-selenium (ITS), pyruvate, glutamine, hypoxantine, BSA, and antibiotics (MEM+) or in MEM+ plus ascorbic acid (5, 25, 50, 100, or 200 μg mL-1). Ovarian tissue was processed for classical histology, TEM, and immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA). Preantral follicles were classified according to their development stage (primordial, intermediate, primary, and secondary) and on the basis of morphological features (normal or degenerated). Pair-wise comparisons were done using Tukey''s procedure. Chi-square test was used to compare percentages of follicles with PCNA-positive granulosa cells. All analyses were done with Statistical Analysis System (SAS Institute, Cary, NC, USA); P≤ 0.05 was considered significant. Compared with control fragments, the percentage of primordial follicles was reduced (P≤ 0.05) and the percentage of growing follicles was increased (P≤ 0.05) in cultured cortical fragments, independent of the tested medium or incubation time. Furthermore, compared with control tissue, culture of ovarian cortex for 8 days reduced the percentages of healthy, viable follicles (P≤0.05), but not when cultures were supplemented with 25, 50, and 100 μg mL-1of ascorbic acid. Ultrastructural and immunohistochemical analysis of ovarian cortical fragments cultured for 8 days, however, showed the integrity and viability of follicles only when fragments were cultured in the presence of 50 μg mL-1of ascorbic acid. In conclusion, this study demonstrated that addition of ascorbic acid to MEM at a concentration of 50 μg mL-1not only stimulates the activation and subsequent growth of cattle primordial follicles that are cultured in vitrofor 8 days but also safeguards the viability of these preantral follicles. E. R. Andrade and A. A. Alfieri are recipients of the PRODOC/CAPES fellowship. [ABSTRACT FROM AUTHOR]