Characterization of the stimulus for reactive oxygen species generation in calcium-overloaded mitochondria

We have used two different probes with distinct detection properties, dichlorodihydrofluorescein diacetate and Amplex Red/horseradish peroxidase, as well as different respiratory substrates and electron transport chain inhibitors, to characterize the reactive oxygen species (ROS) generation by the respiratory chain in calcium-overloaded mitochondria. Regardless of the respiratory substrate, calcium stimulated the mitochondrial generation of ROS, which were released at both the mitochondrial-matrix side and the extramitochondrial space, in a way insensitive to the mitochondrial permeability transition pores inhibitor cyclosporine A. In glutamate/malate-energized mitochondria, inhibition at complex I or complex III (ubiquinone cycle) similarly modulated ROS generation at either mitochondrial-matrix side or extramitochondrial space; this also occurred when the backflow of electrons to complex I in succinate-energized mitochondria was inhibited. On the other hand, in succinate-energized mitochondria the modulation of ROS generation at mitochondrial-matrix side or extra-mitochondrial space depends on the site of complex III which was inhibited. These results allow a straight comparison between the effects of different respiratory substrates and electron transport chain inhibitors on ROS generation at either mitochondrial-matrix side or extra-mitochondrial space in calcium-overloaded mitochondria.

Effects of postnatal protein malnutrition on learning and memory procedures

Protein malnutrition induces structural, neurochemical and functional changes in the central nervous system leading to alterations in cognitive and behavioral development of rats. The aim of this work was to investigate the effects of postnatal protein malnutrition on learning and memory tasks. Previously malnourished (6% protein) and well-nourished rats (16% protein) were tested in three experiments: working memory tasks in the Morris water maze (Experiment I), recognition memory of objects (Experiment II), and working memory in the water T-maze (Experiment III). The results showed higher escape latencies in malnourished animals in Experiment I, lower recognition indexes of malnourished animals in Experiment II, and no differences due to diet in Experiment III. It is suggested that protein malnutrition imposed on early life of rats can produce impairments on both working memory in the Morris maze and recognition memory in the open field tests.

Listening to the Whispers of Matter Through Arabic Hermeticism: New Studies on the Book of the Treasure of Alexander

The Jabirian Corpus refers to the K. Thahirat Al-`Iskandar, ""The Book of the Treasure of Alexander"" (hereafter BTA), as one of several forgeries suggesting that alchemical secrets were hidden in inscriptions in various places. The book was neglected until 1926, when Julius Ruska discussed it in his work on the Emerald Tablet, placing the BTA within the literature related to the development of Arabic alchemy. His preliminary study became an essential reference and encouraged many scholars to work on the BTA in the following decades. Some years ago, we completed the first translation of the BTA into a Western language. The work was based on the acephalous Escorial manuscript, which we identified as a fourteenth-century copy of the BTA. This manuscript is peculiar, as part of it is encoded. After finishing our translation, we started to establish the text of the BTA. At present, the text is in process of fixation-to be followed by textual criticism-and has been the main focus of a thorough study of ours on medieval hermeticism and alchemy. A sample of the work currently in progress is presented in this paper: an analysis of the variations between different manuscripts along with a study and English translation of its alchemical chapter.

Chronic American trypanosomiasis: parasite persistence in endomyocardial biopsies is associated with high-grade myocarditis

Myocyte diameter, fractional area of collagen, intensity of myocarditis and parasite persistence (explored by immunohistochemistry and PCR) were evaluated in serial sections of endomyocardial biopsies from 29 outpatients with chronic chagasic cardiopathy. The patients, 25 males and four females with a mean (S.D.) age of 43 (9) years, were subsequently followed up for 3-2861 days (median=369 days). During this follow-up, 16 (55%) of the patients died. The biopsies revealed myocarditis in 25 (86%) of the patients and high-grade myocarditis in 14 (56%). Although immunohistochemistry failed to demonstrate Trypanosoma cruzi antigens in any of the samples, five (33%) of the 15 biopsies successfully tested in the PCR-based assay for T. cruzi DNA were found positive, indicating parasite persistence. There was a significant positive association between myocardial parasite persistence and high-grade myocarditis (P= 0.014); five (71%,) of the seven endomyocardial biopsies with high-grade myocarditis that were successfully tested in the PCR assays showed persistent T. cruzi DNA. The survival time of the patients was not, however, found to be significantly associated with myocardial parasite persistence, any of the morphometric measurements taken, or the presence or intensity of myocarditis.

Quantitative parameters of facial motor evoked potential during vestibular schwannoma surgery predict postoperative facial nerve function

Background Facial motor evoked potential (FMEP) amplitude ratio reduction at the end of the surgery has been identified as a good predictor for postoperative facial nerve outcome. We sought to investigate variations in FMEP amplitude and waveform morphology during vestibular schwannoma (VS) resection and to correlate these measures with postoperative facial function immediately after surgery and at the last follow-up. Methods Intraoperative orbicularis oculi and oris muscles FMEP data from 35 patients undergoing surgery for VS resection were collected, then analysed by surgical stage: initial, dural opening, tumour dissection (TuDis), tumour resection (TuRes) and final. Findings Immediately after surgery, postoperative facial function correlated significantly with the FMEP amplitude ratio during TuDis, TuRes and final stages in both the orbicularis oculi (p = 0.003, 0.055 and 0.028, respectively) and oris muscles (p = 0.002, 0.104 and 0.014, respectively). At the last follow-up, however, facial function correlated significantly with the FMEP amplitude ratio only during the TuDis (p = 0.005) and final (p = 0.102) stages for the orbicularis oris muscle. At both time points, postoperative facial paresis correlated significantly with FMEP waveform deterioration in orbicularis oculi during the final stage (immediate, p = 0.023; follow-up, p = 0.116) and in orbicularis oris during the TuDis, TuRes and final stages (immediate, p = 0.071, 0.000 and 0.001, respectively; follow-up, p = 0.015, 0.001 and 0.01, respectively). Conclusions FMEP amplitude ratio and waveform morphology during VS resection seem to represent independent quantitative parameters that can be used to predict postoperative facial function. Event-to-baseline FMEP monitoring is quite useful to dictate when intraoperative changes in surgical strategy are warranted to reduce the chances of facial nerve injury.

Early iron deficiency produces persistent damage to visual tracts in Wistar rats

In this study, morphological changes in the optic nerve were determined by light microscopy in Wistar rats on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. The morphometric findings showed significantly fewer blood vessels and oligodendrocytes in the iron-deficient rats and iron-recovery rats than in the control group, as well as more astrocytes in the iron-recovery rats. Serum iron levels of the iron-deficient rats were significantly lower than those of the controls. On the other hand, iron-recovery rats had normal serum iron levels, but no change in the abnormal morphology of the myelinated axons and morphometric parameters. Our data indicate that iron is necessary for maintenance of the optic nerve cell structure, and morphological damage from iron-deficiency is not easily reverted by iron reposition.

Epidemiology of meningococcal disease in Latin America: current situation and opportunities for prevention

Objective: Meningococcal disease continues to be a serious public health concern, being associated with high morbidity and mortality rates in many countries from Latin America. In addition to discussing recent changes in the epidemiology of meningococcal disease in the region, we also analyse the development and potential impact of new vaccines on the prevention of meningococcal disease. Methods: MEDLINE, SciELO, LILACS and websites of the national Ministries of Health databases were searched using the terms meningococcal disease, meningococcal epidemiology, Neisseria meningitidis, meningococcal vaccines and the name of Latin America countries, from 1998 to 2008, with emphasis on review articles, clinical trials and epidemiological studies. Results: Epidemiology of meningococcal disease in Latin America is characterized by marked differences from country to country. The overall incidence of meningococcal disease per year varied from less than 0.1 cases per 100,000 inhabitants in countries like Mexico to two cases per 100,000 inhabitants in Brazil. The highest age-specific incidence of meningococcal disease occurred in infants less than 1 year of age. Serogroups B and C were responsible for the majority of cases reported, but the emergence of serogroups W135 and Y was reported in some countries. Serogroup A disease is now rare in Latin America. Discussion: Although a few countries have established meningitis surveillance programs, the information is not uniform, and the quality of the reported data is poor in the majority of the region. The availability of new effective meningococcal conjugate vaccines and promising protein-based vaccine candidates against meningococcus B highlights the importance of a better understanding of the true burden of meningococcal disease in Latin America and also the need for cost-effectiveness studies before incorporating the new meningococcal vaccines to national immunization programs.

Loss of samples in the tissue microarray technique: comparison between slides using adhesive tape and silanized slides

The tissue microarray (TMA) technique allows multiple tissue samples in a single block. Commercial adhesive tape is used to avoid the loss of tissue samples during the immunostaining process. Few reports exist in the literature comparing the use of these adhesive tapes to other adhesive techniques. The objective of this study was to compare loss of sections adhered to slides using commercial adhesive tapes versus using silanized only slides. TMA was constructed with varying tissues using a fixed-base device (Beecher Instruments), placing 108 cylinders of 1 mm diameter in duplicate, spaced 1.2 mm apart. Section of 4 mu m were cut from the TMA block and adhered to 30 silanized slides and 30 commercial glass slides using adhesive tape, according to manufacturer`s recommendations. Vimentin immunoexpression was evaluated by immunohistochemistry. Antigenic recovery was realized in citrate buffer using a microwave oven. Cylinder loss in the immunohistochemical process was quantified and expressed as: total (>80%), almost complete (75-79%), or partial (50-74%). The commercial adhesive tape group presented lesser total loss (1.1 versus 6.4%), almost complete loss (2.2 versus 3.5%), and partial loss (2.1 versus 3.8%) than the silanized slide group (ANOVA, P < 0.05). The sum of total and almost complete losses in the silanized slide group was 9.9%, greater than the losses in slides using commercial adhesive tapes (3.3%) and less than reported and considered acceptable in the literature (10-30%). In conclusion, the use of silanized only slides presents very satisfactory results, requires less training, and reduces costs significantly, thus justifying their use in research.

Ecological aspects of the free-living ticks (Acari: Ixodidae) on animal trails within Atlantic rainforest in south-eastern Brazil

In a recent ecological study of the ticks on animal trails within an area of Atlantic rainforest in south-eastern Brazil, Amblyomma aureolatum, A. brasiliense, A. incisum, A. ovale and Haemaphysalis juxtakochi were found questing on the vegetation. Most of the ticks recorded by a small, man-made dam on the forest border were A. dubitatum but a few A. brasiliense and A. cajennense, one A. incisum and one H. juxtakochi were also found. The seasonal activity of the ticks indicated that A. incisum and A. brasiliense had one generation/year. On the animal trails, most tick species and stages quested on the vegetation at a height of 30-40 cm above ground level. The questing larvae and adults of A. incisum tended to be found higher, however, with the greatest numbers recorded 40-50 cm (larvae) or 60-70 cm (adults) above ground level. Most of the adult ticks (81.1% -100%), nymphs (78.6%-100%) and larval clusters (100%) found on a forest trail remained questing at the same location over a 24-h period. Carbon-dioxide traps in the rainforest attracted, 50% of the ticks observed questing on the nearby vegetation and, curiously, the CO(2) traps set deep in the forest attracted far fewer ticks than similar traps set by the dam. The ecological relationships between the ticks, their hosts and the rainforest environment are discussed.

Rickettsial infection in Amblyomma nodosum ticks (Acari: Ixodidae) from Brazil

The rickettsial infections in 174 Amblyomma nodosum found on passeriform birds in the Atlantic forest, eastern Brazil, have recently been evaluated. Rickettsiae were successfully isolated from two ticks, using cultures of Vero cells. Both isolates were molecularly characterised, using the rickettsial genes gltA and htrA and, when possible, also ompA and ompB. Portions of the gltA and htrA genes from one of the rickettsial isolates were found be closely match the corresponding GenBank sequences for Rickettsia bellii, with 99.9% and 100% homology, respectively. This isolate was named R. bellii strain Pontal. Portions of the gltA, htrA and ompB genes from the second isolate most closely matched the corresponding sequences of R. parkeri, whereas a portion of the ompA gene from this isolate was closest to the relevant sequence of Rickettsia sp. strain COOPERI (which has been considered to be a strain of R. parkeri in Brazil). The second isolate was named R. parkeri strain NOD. Further investigation of the 172 ticks from which isolates were not recovered revealed R. parkeri strain NOD in 40 and R. bellii strain Pontal in nine, giving overall infection prevalences of 23.6% (41/174) and 5.7% (10/174), respectively. This appears to be the first report of R. bellii and R. parkeri in A. nodosum.

Root Canal Area Increase Promoted by the EndoSequence and ProTaper Systems: Comparison by Computed Tomography

Introduction: The aim of this study was to compare the increase of the root canal area after instrumentation with EndoSequence or ProTaper rotary systems. Methods: Twenty-two mesial root canals from mandibular molars were instrumented. Teeth were mounted on a base, numbered, and divided into 2 groups; teeth from 1-11 (PT group) were instrumented by using the ProTaper system, and teeth from 12-22 (ES group) were instrumented by using the EndoSequence system. Cone beam computed tomography was performed on all teeth before and after instrumentation. Measurements at 3,5, and 7 mm as well as differences in instrument performance were statistically compared by the Student t test at 5% significance level. Results: Both systems increased significantly the root canal area (P < .05) at all levels. Comparison between the rotary systems showed significantly greater increase (P < .05) for EndoSequence at 3 mm, with no statistically significant difference (P < .05) at the other levels. Conclusions: Both rotary systems increased significantly the root canal area. (J Endod 2010;36:1179-1182)

Taxonomic and nomenclatural notes on Guatteria australis (Annonaceae)

Guatteria is the largest genus of Annonaceae, comprising ca. 300 species. The genus presents taxonomic problems, and the number of species has been overestimated. Taxonomic revision, description, comments and illustration of G. australis are presented here. As a result, 41 names have been placed in synonymy under G. australis, and three lectotypes are newly designated.

Paepalanthus hirtellus, a new species of Paepalanthus subsection Actinocephaloides (Eriocaulaceae) from Minas Gerais, Brazil

In this article we describe and illustrate the new species Paepalanthus hirtellus (Eriocaulaceae, Paepalanthoideae). The species is, as far as known, restricted to Pico do Itambe State Park, in the state of Minas Gerais, Brazil. Paepalanthus hirtellus occurs on the campos rupestres of the Espinhaco Range. We compare it with P. lombensis and P. chrysophorus, the two morphologically most similar species. We provide additional comments on the morphological variability, habitat, geographic distribution and we provide its conservation status.

Taxonomic survey of Paepalanthus section Diphyomene (Eriocaulaceae)

Paepalanthus is the largest genus in Eriocaulaceae, comprising about 400 species distributed mainly throughout the Neotropics. Through phylogenetic studies it has been demonstrated that the genus is polyphyletic, although many of its infrageneric categories are monophyletic. In an attempt to clarify the nomenclature and classification of Paepalanthus, we present a taxonomic survey of Paepalanthus section Diphyomene. This group consists of 10 species restricted to South America and is defined by inflorescences being arranged in the form of a tribotryum with terminal dibotryum, a terminal basic unit and pherophylls subtending the lateral dibotrya. Further important distinguishing characteristics are dimerous flowers, pistillate flowers with dolabriform sepals, bifid stigmatic branches and absent staminodes, and staminate flowers with an elongated anthophore. We hereby propose 19 new synonyms, six lectotypifications, one new status, one neotypification and one epitypification.

Two new species of Actinocephalus (Eriocaulaceae) from Minas Gerais, Brazil

We describe and illustrate two new species, Actinocephalus delicatus and A. giuliettiae (Eriocaulaceae, Paepalanthoideae), from the Espinhaco Range in Minas Gerais, Brazil, and compare them with the morphologically most similar species. Diagnostic characters, morphological variation, geographic distribution, habitat and conservation status, as well as line drawings, photos and a distribution map are provided for both species.