A comparison between flexible electrogoniometers,inclinometers and three-dimensional video analysis system for recording neck movement

This study compared neck range of movement recording using three different methods goniometers (EGM), inclinometers (INC) and a three-dimensional video analysis system (IMG) in simultaneous and synchronized data collection. Twelve females performed neck flexion-extension, lateral flexion, rotation and circumduction. The differences between EGM, INC, and IMG were calculated sample by sample. For flexion-extension movement, IMG underestimated the amplitude by 13%; moreover, EGM showed a crosstalk of about 20% for lateral flexion and rotation axes. In lateral flexion movement, all systems showed similar amplitude and the inter-system differences were moderate (4–7%). For rotation movement, EGM showed a high crosstalk (13%) for flexion-extension axis. During the circumduction movement, IMG underestimated the amplitude of flexion-extension movements by about 11%, and the inter-system differences were high (about 17%) except for INC–IMG regarding lateral flexion (7%) and EGM–INC regarding flexion-extension (10%). For application in workplace, INC presents good results compared to IMG and EGM though INC cannot record rotation. EGM should be improved in order to reduce its crosstalk errors and allow recording of the full neck range of movement. Due to non-optimal positioning of the cameras for recording flexion–extension, IMG underestimated the amplitude of these movements.     

Is arsenite more toxic than arsenate in plants?

Ecotoxicology - In order to evaluate the differential absorption and toxicity of arsenate (AsV) and arsenite (AsIII), Lemna valdiviana plants were grown in a nutrient solution and subjected to 0.0...     

Reproductive Biology of Triatoma brasiliensis (Hemiptera,Triatominae) during the Imaginal Molt

The triatomines are vectors of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. These insects are sexually active after the imaginal molt. Some aspects have been studied in Triatoma brasiliensis during the imaginal molt, such as autogeny in virgin females and the relationship between blood ingestion by fifth instar nymph and the realization of the imaginal molt. Thus, to aid in the understanding of reproductive biology and developmental physiology of these vectors, this article analyzes the spermatogenesis of T. brasiliensis during the imaginal molt. The analysis of the seminiferous tubules from males in the fifth instar during imaginal molt has demonstrated that T. brasiliensis has only a few spermatids and a plentiful quantity of sperm. Thus, we suggest that during imaginal molt the cell division is disrupted aiming to reduce energy costs and the differentiation into sperm is stimulated to ensure the paternity of the adult male.Chagas disease is a potentially life-threatening illness caused by the protozoan parasite Trypanosoma cruzi and transmitted to humans by contact with feces of triatomine bugs, known as “kissing bugs.”¹ These vectors have a typical hemimetabolous life cycle, from eggs through five nymphal instars (N1, N2, N3, N4, and N5) to adult males and females. The transition from the fifth instar nymph to adult is named imaginal molt. During this process it occur some corporal changes, such as the emergence of wings,² exocrine glands (metasternal and Brindley''s glands)^3,4 and development of the reproductive system.^5–8Some aspects have been studied in Triatoma brasiliensis Neiva, 1911 during the imaginal molt, such as autogeny in virgin females⁹ and the relationship between blood ingestion by N5 and the realization of the imaginal molt.¹⁰ This triatomine species is the most important Chagas disease vector in the Brazilian northeast.^11,12 Thus, to aid in the understanding of the reproductive biology and developmental physiology of these vectors, this article analyzes the spermatogenesis of T. brasiliensis during the imaginal molt.Five males in the fifth instar nymphs of T. brasiliensis were isolated and during imaginal molt their testicles were removed and fixed in methanol: acetic acid (3:1). They had been assigned by the “Triatominae Insectarium” within the Department of Biological Sciences, in the College of Pharmaceutical Sciences, at Sao Paulo State University''s “Júlio de Mesquita Filho,” Araraquara campus. The colony was formed from T. brasiliensis collected in intradomiciliary region of the municipality Olho d''Água, State of Paraiba, Brazil in the day April 17, 2008.Seminiferous tubules were first shredded, smashed, and the microscope slides were set in liquid nitrogen. They were then stained with the lacto-acetic orcein cytogenetic technique.^13,14 On the basis of the analysis of slides, it was observed that the N5 nymphs, during imaginal molt, have only one of the phases of spermatogenesis, that is, the spermiogenesis. This is represented by the presence of spermatids (Figure 1A –C) and sperm (Figure 1D).Open in a separate windowFigure 1.Spermiogenesis in Triatoma brasiliensis. Note the elongation of spermatids (A–C) and sperm (D). Bar: 10 μm.Spermatogenesis is the process by which sperms are produced in the seminiferous tubules. It consists of three different phases: spermatocitogenesis, which is a phase of multiplication; meiosis, which is the division phase; and spermiogenesis, which is the differentiation phase.¹⁵Perez and others,¹⁶ reported that in some cases fifth instar nymph have mature gonads. Mello and collaborators,¹⁷ analyzed fifth instar nymph of Triatoma infestans and observed the presence of spermatogonia, spermatocytes (metaphase), spermatids, and sperms. However, during imaginal molt of T. brasiliensis there are only a few spermatids and a plentiful quantity of sperm were observed, and we suggest that during imaginal molt, the cell division is disrupted aiming to reduce energy costs, and the differentiation into sperm is stimulated to ensure the paternity of the adult male.There are some offensive mechanisms that increase the chances to ensure the paternity, such as the characteristics of the genitalia,¹⁸ the seminal fluid,¹⁹ and the courtship behavior.²⁰ Taking it into account, we suggest that the excessive increase of sperms during imaginal molt also increase the chances for the paternity.Thus, we suggest that during the imaginal molt T. brasiliensis showed changes in the reproductive biology of development and physiology to decrease the energy cost, ensuring that the molt occur and mainly to increase the chance of paternity in adults. These results provide important information for understanding the biology of this important vector of the Chagas disease. However, we highlight that new species and a larger number of triatomines should be analyzed to characterize whether this phenomenon occurs in all species of Triatominae subfamily.     

Adjuvant Therapy With Sodium Alendronate for the Treatment of Experimental Periodontitis in Rats

Background: This study assesses the effects of topical sodium alendronate (SA) as an adjuvant to the mechanical treatment of ligature‐induced periodontitis in rats. Methods: Ninety animals were subjected to the induction of periodontitis via the installation of a ligature around the mandibular left first molar. After 7 days, the ligature was removed, and the animals were distributed into the following groups: 1) NT group (n = 30), no treatment; 2) SRP group (n = 30), scaling and root planing (SRP) and local irrigation with physiologic saline solution; and 3) SRP/SA group (n = 30), SRP and local irrigation with SA (10^?5 M). Ten animals from each group were euthanized at 7, 15, and 30 days after treatment. Histologic and histometric analyses were performed in the furcation region. The percentage of bone in the furcation (PBF) was measured. Immunohistochemical analyses for detecting the receptor activator of nuclear factor‐κB ligand (RANKL), osteoprotegerin (OPG), tartrate‐resistant acid phosphatase (TRAP), and activated caspase‐3 were performed at the furcation region. Results: Compared with the other groups, the SRP/SA group showed less local inflammation and better tissue reparation during the entire experiment. There was more PBF in the SRP/SA group than in the other groups at days 7 and 15. Stronger OPG immunolabeling and weaker RANKL immunolabeling were observed in the SRP/SA group at 15 and 30 days. There were fewer TRAP‐positive cells in the SRP/SA group than in the NT group at all of the time points. There was no difference in the number of activated caspase‐3‐positive osteocytes among groups and time points. Conclusion: It can be concluded that topical use of SA as an adjuvant to SRP is effective in the treatment of experimental periodontitis.     

Estrogen therapy attenuates adiposity markers in spontaneously hypertensive rats

Ovarian hormones modulate the metabolism of adipose cells and present a protective effect against hypertension. The aim of this study was to compare the effect of estradiol on adiposity markers in spontaneously hypertensive rats. Ovariectomized spontaneously hypertensive rats treated with estradiol (5 μg/100 g/day), three weeks after ovariectomy, presented decreased blood pressure and insulin levels and increased hepatic glycogen content. Periuterine or mesenteric adipocytes from treated animals were smaller as compared to vehicle treated group, whereas no differences were observed in relation to the number of cells. Basal rates of glycerol release were higher only in periuterine adipocytes of treated rats. The increment of glycerol release over basal values in response to isoproterenol was 400% and 440%, 283% and 330% for vehicle and estradiol treated periuterine and mesenteric adipocytes, respectively. The estradiol treated group was more sensitive to insulin inhibition of isoproterenol-stimulated lipolysis than the control animals. The lipoprotein lipase activity decreased after treatment, only in periuterine adipose tissue. Estradiol administration increased basal and insulin-stimulated rates of glucose transport in adipocytes of both sites, although the values obtained by periuterine were higher than those observed for mesenteric adipocytes. Both adipose tissues from treated animals exhibited a decreased expression of the peroxisome proliferator-activated receptor-γ, but an increased expression of peroxisome proliferator-activated receptor-α in liver. These findings suggest that estrogen administration attenuates adiposity markers of spontaneously hypertensive rats as a result of the decreased expression levels of peroxisome proliferator-activated receptor-γ in adipose tissue and increased expression of peroxisome proliferator-activated receptor-α in liver.