OBJECTIVEThis paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil (5 degrees S, 42 degrees W).

MATERIALS AND METHODSThirty Wistar-Hannover rats, three months old, were randomly divided into three groups of 10 animals each: Group I [control, without exposure to ultraviolet (UV) radiation], Group II (exposed to sunlight during 08:00 a.m. to 10:00 a.m.), and Group III (exposed to sunlight during 10:00 a.m. to 12:00 a.m.). After a week of exposure, peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal. In 24 h after exposure to sunlight in Group III, a new collection was obtained to observe the repair activity. The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight (P < 0.05).

RESULTSThere was no statistical difference between Group I and II (P = 0.672). On the other hand, the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups (P < 0.0001). Also, there was no significant repair in Group III R (P = 0.407).

CONCLUSIONThis study has shown a genotoxic potential of sunlight (UVA-B) in lymphocytes of mammals from 10:00 a.m. to 12:00 a.m., due to a higher intensity of UV in this tropical region.

Animals ; Comet Assay ; DNA Damage ; Lymphocytes ; radiation effects ; Rats ; Rats, Wistar ; Sunlight

To establish reference values for the cervical length (CL) measurement by transvaginal ultrasound between 20 and 24+6 weeks of gestation in a large Brazilian population. A retrospective cross-sectional study was performed with 996 singleton pregnancies. The CL measurement (mm) using the transvaginal ultrasound was obtained in a sagittal view and the calipers positioned to measure the linear distance between the triangular area of echodensity at the external os and the internal os. The median±standard deviation and ranges for the CL measurement (mm) was 37.0±10.7 (range, 8 to 51). CL measurement did not modify significantly with gestational age. The observed percentiles for the CL measurement (mm) considering all number case were the following: 5th, 28 mm; 50th, 37 mm; and 95th, 45 mm. Reference values for the CL measurement by transvaginal ultrasound between 20 and 24+6 weeks of gestation in a large heterogeneous Brazilian population were established.
Cervical Length Measurement* ; Cervix Uteri ; Cross-Sectional Studies ; Female ; Gestational Age ; Humans ; Pregnancy ; Pregnancy Trimester, Second* ; Pregnancy* ; Reference Values* ; Retrospective Studies ; Ultrasonography*

PURPOSE: We sought to evaluate the effectiveness of bone substitutes in circumferential peri-implant defects created in the rabbit tibia. METHODS: Thirty rabbits received 45 implants in their left and right tibia. A circumferential bone defect (6.1 mm in diameter/4 mm depth) was created in each rabbit tibia using a trephine bur. A dental implant (4.1 mm × 8.5 mm) was installed after the creation of the defect, providing a 2-mm gap. The bone defect gaps between the implant and the bone were randomly filled according to the following groups: blood clot (CO), particulate Bio-Oss® (BI), and Bio-Oss® Collagen (BC). Ten animals were euthanized after periods of 15, 30, and 60 days. Biomechanical analysis by means of the removal torque of the implants, as well as histologic and immunohistochemical analyses for protein expression of osteocalcin (OC), Runx2, OPG, RANKL, and TRAP were evaluated. RESULTS: For biomechanics, BC showed a better biological response (61.00±15.28 Ncm) than CO (31.60±14.38 Ncm) at 30 days. Immunohistochemical analysis showed significantly different OC expression in CO and BC at 15 days, and also between the CO and BI groups, and between the CO and BC groups at 60 days. After 15 days, Runx2 expression was significantly different in the BI group compared to the CO and BC groups. RANKL expression was significantly different in the BI and CO groups and between the BI and BC groups at 15 days, and also between the BI and CO groups at 60 days. OPG expression was significantly higher at 60 days postoperatively in the BI group than the CO group. CONCLUSIONS: Collectively, our data indicate that, compared to CO and BI, BC offered better bone healing, which was characterized by greater RUNX2, OC, and OPG immunolabeling, and required greater reversal torque for implant removal. Indeed, along with BI, BC presents promising biomechanical and biological properties supporting its possible use in osteoconductive grafts for filling peri-implant gaps.
Animals ; Bone Substitutes* ; Bone Transplantation ; Collagen ; Dental Implantation ; Dental Implants ; Osseointegration ; Osteocalcin ; Rabbits ; Tibia* ; Torque ; Transplants

The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower IC₅₀ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.
Amphibian Venoms* ; Animals ; Biodiversity ; Brazil* ; Bufo marinus ; Malaria ; Neutral Red ; Parasites ; Plasmodium falciparum

BACKGROUND/AIMS: Lipopolysaccharide (LPS) is a molecule formed by lipids and polysaccharides and is the major cell wall component of gram-negative bacteria. High LPS levels are known to block CD26 expression by activating Toll-like receptor 4. The aim of this study was to correlate the serum levels of LPS and CD26 in Crohn's disease (CD) patients with serum levels of C-reactive protein (CRP), interleukins, CD activity index, and tumor necrosis factor-α (TNF-α). METHODS: Serum samples were collected from 27 individuals (10 with active CD, 10 with inactive CD, and 7 controls) and the levels of LPS, CD26, TNF-α, interleukin-1β (IL-1β), IL-6, IL-17, and CRP were determined by enzyme-linked immunosorbent assay. The levels of LPS and CD26 were then tested for correlation with TNF-α, IL-1β, IL-6, IL-17, and CRP. RESULTS: Serum levels of LPS were significantly elevated in the active CD group (P=0.003). Levels of IL-1β (P=0.002), IL-6 (P=0.003), and IL-17 (P<0.001) were lower in the CD groups. Serum TNF-α levels were increased in the active CD group. The CRP levels were elevated in the CD groups when compared to controls (P<0.001). The CD26 levels were lower in the CD groups than in the control group (P<0.001). Among the variables analyzed, there was a correlation between LPS and CRP (r=−0.53, P=0.016) in the CD groups. CONCLUSIONS: Individuals with CD exhibited higher serum levels of LPS varying from a 2- to 6-fold increase depending on disease activity, when compared with healthy controls. CD26 levels were lower in the CD groups. Both LPS and CD26 correlated with disease severity and serve as potential CD biomarkers.
Biomarkers ; C-Reactive Protein ; Cell Wall ; Crohn Disease* ; Enzyme-Linked Immunosorbent Assay ; Gram-Negative Bacteria ; Humans ; Inflammatory Bowel Diseases ; Interleukin-17 ; Interleukin-6 ; Interleukins ; Lipopolysaccharides* ; Necrosis ; Polysaccharides ; Toll-Like Receptor 4