Influence of temperature upon paralyzing and myotoxic effects of bothropstoxin-I on mouse neuromuscular preparations

Bothropstoxin-I (BthTX-I), from B. jararacussu venom, is a phospholipase A(2) (PLA(2)) homologue devoid of enzymatic activity. Besides inducing severe myonecrosis, BthTX-I promotes paralysis of both directly and indirectly evoked contractions in isolated neuromuscular preparations. We applied an experimental paradigm in order to characterize the steps involved in the toxic effects of BthTX-I on mouse neuromuscular junction. Myotoxicity was assessed by microscopic analysis of extensor digitorum longus muscles; paralyzing activity was evaluated through the recording of isolated contractions indirectly evoked in phrenic-diaphragm preparations. After 90 min at 35 degreesC, BthTX-I induced complete and irreversible paralysis, and damaged 30.3 +/- 2.7% of muscle fibers. In contrast, no effect was observed when tissues were incubated with BthTX-I at 10degreesC for 60 min and subsequently washed with toxin-free solution and maintained at 35 degreesC. These results indicate that the binding of BthTX-I to the cellular tissue surface is very weak at low temperature and that an additional factor is necessary. However, when tissues were submitted to BthTX-I (10degreesC for 60 min), and the temperature was elevated to 35 degreesC, omitting the washing step, it was observed muscle paralysis and damage in 39.04 +/- 4.2% of muscle fibers. These results indicate that a temperature-dependent step is necessary for BthTX-I to promote both its myotoxic and paralyzing activities. (C) 2004 Elsevier B.V.. All rights reserved.

The Use of Etoricoxib and Celecoxib for Pain Prevention After Periodontal Surgery: A Double-Masked, Parallel-Group, Placebo-Controlled, Randomized Clinical Trial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preemptive dexamethasone and etoricoxib for pain and discomfort prevention after periodontal surgery: A double-masked, crossover, controlled clinical trial

Background: Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. Methods: For this prospective, double-masked, crossover, placebo-controlled, randomized clinical trial, open-flap debridement surgeries were performed on 15 patients (eight males and seven females, age range 20 to 56 years: mean age ± SD: 40 ± 9.7 years) who presented with chronic periodontitis after nonsurgical periodontal therapy at three quadrants. Each patient underwent three surgical procedures at intervals of 30 days and received one of the following premedication protocols 1-hour before surgery: group 1 = placebo, group 2 = 8 mg dexamethasone, and group 3 = 120 mg etoricoxib. Rescue medication (750 mg acetaminophen) was given to each patient who was instructed to take it when necessary. Pain intensity and discomfort were evaluated by a 101-point numeric rate scale and a four-point verbal rate scale, respectively, hourly for the first 8 hours after surgery and three times a day on the following 3 days. Results: The results demonstrate that groups 2 and 3 present reduced postoperative pain-intensity levels compared to group 1. There were statistically significant differences at the 4, 5, 6, 7, and 8 hour-periods after surgery (Friedman test; P<0.05). Furthermore, rescue-medication intake was significantly lower for groups 2 and 3 than for group 1 (analysis of variance; P<0.02). Conclusion: The adoption of a preemptive medication protocol using etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

Ação do paracoxibe e/ou imipenem na cicatrização das anastomoses do intestino delgado e cólon de ratos: estudo biomecânico e anatomopatológico

Pós-graduação em Bases Gerais da Cirurgia - FMB

An Isoflavone from Dipteryx alata Vogel is Active against the in Vitro Neuromuscular Paralysis of Bothrops jararacussu Snake Venom and Bothropstoxin I, and Prevents Venom-Induced Myonecrosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vasoconstrictor effect of Africanized honeybee (Apis mellifera L.) venom on rat aorta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Quantificação imunofenotípica de células T reguladoras em cães acometidos por linfoma multicêntrico submetidos ao protocolo quimioterápico chop associado ou não a um firocoxib

Pós-graduação em Medicina Veterinária - FCAV

Efeitos da dose única de parecoxibe sobre a morte celular em rins de ratos submetidos à hemorragia aguda

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis and characterization of an antibacterial and non-toxic dimeric peptide derived from the C-terminal region of Bothropstoxin-I

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of prognostic factors and survival rates in malignant feline mammary gland neoplasms

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Combined snake venomics and venom gland transcriptomic analysis of Bothropoides pauloensis

Unraveling the repertoire of venom toxins of Bothropoides pauloensis was assessed by snake venomics and venom gland transcriptomic surveys. Both approaches yielded converging overall figures, pointing to metalloproteinases (similar to 37%), PLA(2)s (26-32%), and vasoactive (bradykinin-potentiating) peptides (12-17%) as the major toxin classes. The high occurrence of SVMPs, PLA(2) molecules, vasoactive peptides, along with serine proteinases, explains the local and systemic effects observed in envenomations by B. pauloensis. Minor (<3%) C-type lectin, serine proteinase, L-amino acid oxidase, nerve growth factor, and CRISP molecules were also identified in the transcriptome and the proteome. Low abundance (0.3%) EST singletons coding for vascular endothelial growth factor (svVEGF), ohanin, hyaluronidase, and 5' nucleotidase were found only in the venom gland cDNA library. At the molecular level, the transcriptomic and proteomic datasets display low compositional concordance. In particular, although there is good agreement between transcriptome and proteome in the identity of BPPs, PLA(2) molecules and L-amino acid oxidase, both datasets strongly depart in their C-type lectin and SVMP complements. These data support the view that venom composition is influenced by transcriptional and translational mechanisms and emphasize the value of combining proteomic and transcriptomic approaches to acquire a more complete understanding of the toxinological profile and natural history of the snake venom. (C) 2012 Elsevier B.V. All rights reserved.

Celecoxib treatment does not alter recruitment and activation of osteoclasts in the initial phase of experimental tooth movement

In a previous study, we reported that the short-term treatment with celecoxib, a nonsteroidal anti-inflammatory drug (NSAID) attenuates the activation of brain structures related to nociception and does not interfere with orthodontic incisor separation in rats. The conclusion was that celecoxib could possibly be prescribed for pain in orthodontic patients. However, we did not analyze the effects of this drug in periodontium. The aim of this follow-up study was to analyze effects of celecoxib treatment on recruitment and activation of osteoclasts and alveolar bone resorption after inserting an activated orthodontic appliance between the incisors in our rat model. Twenty rats (400420 g) were pretreated through oral gavage with celecoxib (50 mg/kg) or vehicle (carboxymethylcellulose 0.4%). After 30 min, they received an activated (30 g) orthodontic appliance, set not to cause any palate disjunction. In sham animals, the appliance was immediately removed after introduction. All animals received ground food and, every 12 h, celecoxib or vehicle. After 48 h, they were anesthetized and transcardiacally perfused through the aorta with 4% formaldehyde. Subsequently, maxillae were removed, post-fixed and processed for histomorphometry or immunohistochemical analyses. As expected, incisor distalization induced an inflammatory response with certain histological changes, including an increase in the number of active osteoclasts at the compression side in group treated with vehicle (appliance: 32.2 +/- 2.49 vs sham: 4.8 +/- 1.79, P<0.05) and celecoxib (appliance: 31.0 +/- 1.45 vs sham: 4.6 +/- 1.82, P<0.05). The treatment with celecoxib did not modify substantially the histological alterations and the number of active osteoclasts after activation of orthodontic appliance. Moreover, we did not see any difference between the groups with respect to percentage of bone resorption area. Taken together with our previous results we conclude that short-term treatment with celecoxib can indeed be a therapeutic alternative for pain relieve during orthodontic procedures.

DETERMINATION OF DICLOFENAC SODIUM IN RABBIT PLASMA BY HPLC/UV: EVALUATION AND CHARACTERIZATION OF ITS CRYSTALLINE FORMS, ANHYDROUS AND HYDRATE, ON THE ANTIPYRETIC EFFECT

Diclofenac sodium (DS) is a non-steroidal anti-inflammatory drug that is widely prescribed for the treatment of rheumatoid arthritis and post-surgery analgesia. The active pharmaceutical ingredient is the anhydrous form; however, it can also exist in hydrate form. In this context, knowing the properties of the solid state is important and relevant in the pharmaceutical area because they have a significant impact on the solubility, bioavailability, and chemical stability of the drugs. In the present study, data from XRPD, FTIR spectroscopy, and thermal analysis were used for the identification and characterization of DS forms (anhydrous and hydrate). An HPLC method was optimized to evaluate the plasma concentration of DS in rabbits. The optimized method exhibited good linearity over the range 0.1-60 mu g/mL with correlation coefficients of >0.9991. The mean recovery was 100%. Precision and accuracy were determined within acceptable limits. Finally, to compare the pharmacological properties of anhydrous and hydrate DS forms, we investigated their effects in the febrile response induced by lipopolysaccharide from E. coli in rabbits. The results show that the antipyretic effect of anhydrous and hydrate DS forms are similar.

Sublingual ketorolac and sublingual piroxicam are equally effective for postoperative pain, trismus, and swelling management in lower third molar removal

Objective. Lower third molar removal provides a clinical model for studying analgesic drugs. The present study's aim was to compare the clinical efficacy of sublingual ketorolac and sublingual piroxicam in managing pain, trismus and swelling after lower third molar extraction in adult volunteers. Study Design. In this double-blinded, randomized, crossover investigation, 47 volunteers received for 4 days ketorolac sublingually (10 mg 4 times daily) and piroxicam sublingually (20 mg once daily) during 2 separate appointments after lower third molar extraction of symmetrically positioned lower third molars. A surgeon evaluated objective parameters (surgery duration, mouth opening, rescue analgesic medication, and facial swelling) and volunteers documented subjective parameters (postoperative pain and global evaluation), comparing postoperative results for a total of 7 days after surgery. The means of the objective and subjective parameters were compared for statistical significance (P < .05). Results. Volunteers reported low pain scores during the postoperative period when treated with either sublingual ketorolac or piroxicam. Also, volunteers ingested similar amounts of analgesic rescue medication (paracetamol) when they received either drug sublingually (P > .05). Additionally, values for mouth openings measured just before surgery and immediately after suture removal 7 days later were similar among volunteers (P > .05), and the type of nonsteroidal antiinflammatory drug (NSAID) used in this study showed no significant differences between swellings on the second or seventh days after surgery (P > .05). Conclusions. Pain, trismus, and swelling after lower third molar extraction, independent of surgical difficulty, were successfully controlled by sublingual ketorolac (10 mg 4 times daily) or sublingual piroxicam (20 mg once daily), and no significant differences were observed between the NSAIDs evaluated. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:27-34)

Isolation, enzymatic characterization and antiedematogenic activity of the first reported rattlesnake hyaluronidase from Crotalus durissus terrificus venom

A hyaluronidase (CdtHya1) from Crotalus durissus terrificus snake venom (CdtV) was isolated and showed to exhibit a high activity on hyaluronan cleavage. However, surveys on this enzyme are still limited. This study aimed at its isolation, functional/structural characterization and the evaluation of its effect on the spreading of crotoxin and phospholipase A(2) (PLA(2)). The enzyme was purified through cation exchange, gel filtration and hydrophobic chromatography. After that, it was submitted to a reverse-phase fast protein liquid chromatography (RP-FPLC) and Edman degradation sequencing, which showed the first N-terminal 44 amino acid residues whose sequence evidenced identity with other snake venom hyaluronidases. CdtHya1 is a monomeric glycoprotein of 64.5 kDa estimated by SDS-PAGE under reducing conditions. It exhibited maximum activity in the presence of 0.2 M NaCl, at 37 degrees C, pH 5.5 and a specificity to hyaluronan higher than that to chondroitin-4-sulphate, chondroitin-6-sulphate or dermatan. Divalent cations (Ca2+ and Mg2+) and 1 M NaCl significantly reduced the enzyme activity. The specific activity of CdtHya1 was 5066 turbidity reducing units (TRU)/mg, against 145 TRU/mg for the soluble venom, representing a 34.9-fold purification. The pure enzyme increased the diffusion of crotoxin and PLA (2) through mice tissues. CdtHya1 (32 TRU/40 mu L) potentiated crotoxin action, as evidenced by mice death, and it decreased the oedema caused by subplantar injections of buffer, crotoxin or PLA(2), thus evidencing the relevance of hyaluronidase in the crotalic envenoming. This work yielded a highly active antiedematogenic hyaluronidase from CdtV, the first one isolated from rattlesnake venoms. (C) 2012 Elsevier Masson SAS. All rights reserved.