Growth factors expression and ultrastructural morphology after application of low-level laser and natural latex protein on a sciatic nerve crush-type injury.

The effects of low-level laser therapy (LLLT) and natural latex protein (F1, Hevea brasiliensis) were evaluated on crush-type injuries (15kg) to the sciatic nerve in the expressions of nerve growth factor (NGF) and vascular endothelium growth factor (VEGF) and ultrastructural morphology to associate with previous morphometric data using the same protocol of injury and treatment. Thirty-six male rats were allocated into six experimental groups (n = 6): 1-Control; 2-Exposed nerve; 3-Injured nerve; 4-LLLT (15J/cm2, 780nm, 30mW, Continuous Wave) treated injured nerve; 5-F1 (0,1mg) treated injured nerve; and 6-LLLT&F1 treated injured nerve. Four or eight weeks after, sciatic nerve samples were processed for analysis. NGF expression were higher (p<0.05) four weeks after in all injured groups in comparison to Control (Med:0.8; Q1:0; Q3:55.5%area). Among them, the Injured (Med:70.7; Q1:64.4; Q3:77.5%area) showed the highest expression, and F1 (Med:17.3; Q1:14.1; Q3:21.7%area) had the lowest. At week 8, NGF expressions decreased in the injured groups. VEGF was expressed in all groups; its higher expression was observed in the injured groups 4 weeks after (Injured. Med:29.5; F1. Med:17.7 and LLLT&F1. Med:19.4%area). At week 8, a general reduction of VEGF expression was noted, remaining higher in F1 (Med:35.1; Q1.30.6; Q3.39.6%area) and LLLT&F1 (Med:18.5; Q1:16; Q3:25%area). Ultrastructural morphology revealed improvements in the treated groups; 4 weeks after, the F1 group presented greater quantity and diameter of the nerve fibers uniformly distributed. Eight weeks after, the F1 and LLLT&F1 showed similar characteristics to the non-injured groups. In summary, these results and our previous studies indicated that F1 and LLLT may favorably influence the healing of nerve crush injury. Four weeks after nerve injury F1 group showed the best results suggesting recovery acceleration; at 8th week F1 and LLLT&F1 groups presented better features and higher vascularization that could be associated with VEGF maintenance.

The study of the use of a latex biomembrane and conjunctival autograft in rabbit conjunctiva wound healing.

RESUMO Objetivo: Estudar o uso da biomembrana de látex e o transplante conjuntival autólogo na cicatrização conjuntival em coelhos. Métodos: Em nove coelhos albinos, neo-zelandeses, machos foram removidas áreas retangulares idênticas, do quadrante supero nasal, adjacente ao limbo, de ambos os olhos. As áreas desnudas da camada esclerótica nos olhos direitos foram recobertas com biomembrana de látex e a dos olhos esquerdos com enxerto conjuntival autólogo. Os animais foram sacrificados em grupos de três, aos 7, 14 e 21 dias após a cirurgia. Os tecidos do local cirúrgico, incluindo a córnea, foram fixados em formaldeído, antes de serem processados em parafina e corados com hematoxilina e eosina. A natureza e a intensidade da resposta inflamatória e o padrão de epitelização da superfície conjuntival foram avaliados sob microscopia óptica, em seções histológicas longitudinais, passando pelo centro dos espécimes anatômicos. Resultados: Até o décimo quarto dia pós-operatório, o grupo que recebeu a biomembrana apresentou reação inflamatória mais intensa do que o grupo com auto enxerto conjuntival. Aos 14 dias, os olhos com biomembrana apresentavam-se menos inflamados e com estroma mais espesso do que aos 7 dias. Aos 21 dias, a reparação conjuntival de ambos os grupos apresentavam características semelhantes. Conclusão: Apesar de apresentar uma cicatrização mais lenta, a biomembrana de látex se mostrou tão eficaz quanto o auto enxerto conjuntival na reconstrução da superfície ocular após três semanas de cicatrização pós-operatória. Devido as suas baixas toxicidade e alergenicidade, este material parece ser uma opção terapêutica promissora na reconstrução da conjuntiva.ABSTRACT Purpose: To study a latex biomembrane and conjunctival autograft with regard to the promotion of conjunctival healing in rabbits. METHODS: The study included nine male albino rabbits. In these rabbits, a rectangular area of the conjunctiva was surgically removed from the superonasal quadrant adjacent to the limbus in both eyes. The bare area of the sclerotic coat of the right eye was reconstructed with a latex biomembrane, and the corresponding site of the left eye was reconstructed with a conjunctival autograft. The animals were killed in groups of three at 7, 14, and 21 days after surgery. The tissues from the surgical site, including the cornea, were fixed in formaldehyde, and were then processed in paraffin and stained with hematoxylin and eosin. The nature and intensity of the inflammatory response and the epithelial pattern at the conjunctival surface were evaluated under optical microscopy with longitudinal histological sections through the center of the anatomical specimens. RESULTS: Until the 14th postoperative day, the inflammatory reaction was greater in the biomembrane group than in the conjunctival autograft group. In the latex biomembrane group, inflammation was less intense and the stroma was thicker on the 14th postoperative day than on the 7th postoperative day. After three weeks, conjunctival healing in both groups showed similar characteristics. CONCLUSION: Although healing was slower with a latex biomembrane, tissue reconstitution was almost the same as that with a conjunctival autograft by three weeks. A latex biomembrane is as effective as a conjunctival autograft for the reconstruction of the ocular surface. Owing to the lack of toxicity and allergenicity, a latex biomembrane appears to be a promising therapeutic option for conjunctival reconstruction.

The study of the use of a latex biomembrane and conjunctival autograft in rabbit conjunctiva wound healing / Estudo do implante de biomembrana de látex e auto-enxerto conjuntival em cicatrização de ferida conjuntiva de coelho

RESUMO Objetivo: Estudar o uso da biomembrana de látex e o transplante conjuntival autólogo na cicatrização conjuntival em coelhos. Métodos: Em nove coelhos albinos, neo-zelandeses, machos foram removidas áreas retangulares idênticas, do quadrante supero nasal, adjacente ao limbo, de ambos os olhos. As áreas desnudas da camada esclerótica nos olhos direitos foram recobertas com biomembrana de látex e a dos olhos esquerdos com enxerto conjuntival autólogo. Os animais foram sacrificados em grupos de três, aos 7, 14 e 21 dias após a cirurgia. Os tecidos do local cirúrgico, incluindo a córnea, foram fixados em formaldeído, antes de serem processados em parafina e corados com hematoxilina e eosina. A natureza e a intensidade da resposta inflamatória e o padrão de epitelização da superfície conjuntival foram avaliados sob microscopia óptica, em seções histológicas longitudinais, passando pelo centro dos espécimes anatômicos. Resultados: Até o décimo quarto dia pós-operatório, o grupo que recebeu a biomembrana apresentou reação inflamatória mais intensa do que o grupo com auto enxerto conjuntival. Aos 14 dias, os olhos com biomembrana apresentavam-se menos inflamados e com estroma mais espesso do que aos 7 dias. Aos 21 dias, a reparação conjuntival de ambos os grupos apresentavam características semelhantes. Conclusão: Apesar de apresentar uma cicatrização mais lenta, a biomembrana de látex se mostrou tão eficaz quanto o auto enxerto conjuntival na reconstrução da superfície ocular após três semanas de cicatrização pós-operatória. Devido as suas baixas toxicidade e alergenicidade, este material parece ser uma opção terapêutica promissora na reconstrução da conjuntiva.

ABSTRACT Purpose: To study a latex biomembrane and conjunctival autograft with regard to the promotion of conjunctival healing in rabbits. Methods: The study included nine male albino rabbits. In these rabbits, a rectangular area of the conjunctiva was surgically removed from the superonasal quadrant adjacent to the limbus in both eyes. The bare area of the sclerotic coat of the right eye was reconstructed with a latex biomembrane, and the corresponding site of the left eye was reconstructed with a conjunctival autograft. The animals were killed in groups of three at 7, 14, and 21 days after surgery. The tissues from the surgical site, including the cornea, were fixed in formaldehyde, and were then processed in paraffin and stained with hematoxylin and eosin. The nature and intensity of the inflammatory response and the epithelial pattern at the conjunctival surface were evaluated under optical microscopy with longitudinal histological sections through the center of the anatomical specimens. Results: Until the 14th postoperative day, the inflammatory reaction was greater in the biomembrane group than in the conjunctival autograft group. In the latex biomembrane group, inflammation was less intense and the stroma was thicker on the 14th postoperative day than on the 7th postoperative day. After three weeks, conjunctival healing in both groups showed similar characteristics. Conclusion: Although healing was slower with a latex biomembrane, tissue reconstitution was almost the same as that with a conjunctival autograft by three weeks. A latex biomembrane is as effective as a conjunctival autograft for the reconstruction of the ocular surface. Owing to the lack of toxicity and allergenicity, a latex biomembrane appears to be a promising therapeutic option for conjunctival reconstruction.

Bone repair of critical-sized defects in Wistar rats treated with autogenic, allogenic or xenogenic bone grafts alone or in combination with natural latex fraction F1.

Bone grafts are used in the medical-surgical field for anatomical and functional reconstruction of lost bone areas, aiding the bone repair process by osteogenesis, osteinduction and osteoconduction. New materials such as F1 (fraction 1) protein extracted from the rubber tree Hevea brasiliensis have been investigated and currently present important properties for tissue repair, and are associated with neoangiogenesis, promoting cell adhesion and extracellular matrix formation. The main objective of this study was to investigate the association of F1 protein to different bone grafts in the repair of critical bone defects in the calvaria of Wistar rats. A total of 112 Wistar rats were divided as follows: autograft (AuG), allograft (AlG), xenograft (XeG), autograft/F1 (AuG-F1), allograft/F1 (AlG-F1), xenograft/F1 (XeG-F1), F1 (F1), control (CTL), with a waiting period of 4 and 6 weeks (w). The stereological AuG, AlG, AuG-F1 and AlG-F1 results had greater bone neoformation (p < 0.05). For immunohistochemistry, the angiogenic and osteogenic factors were higher for AuG-F1 and AlG-F1. TRAP-positive cells were higher in XeG-F1 and AlG (37 ± 9.53, 13.3 ± 4.16) (4 w) and XeG, AlG-F1 and XeG-F1 (20.33 ± 7.37; 15.25 ± 6.02, 19.33 ± 3.21) (6 w). For zymography, F1 showed increased gelatinolytic activity of MMP-2 and -9. It was concluded that the bone graft associated or not with F1 increases the angiogenic and osteogenic, biochemical and stereological factors.

Isolation and chemical characterization of agelaiatoxin8 (AvTx8) from Agelaia vicina wasp venom and its biological effects on GABA neurotransmission.

Arthropod venoms are sources of molecules that may be useful tools to investigate molecular mechanisms of putative new medicines and laboratory drugs. Here we show the effects of the compound agelaiatoxin-8 (AVTx8), isolated from Agelaia vicina venom, on γ-aminobutyric acid (GABA) neurotransmission in rat brain synaptosomes. Analysis reveals that AvTx8 is composed by 14 amino acid residues with a molecular weight (MW) of 1567 Da. AvTx8 increased GABA release and inhibited GABA uptake in synaptosomes from rat cerebral cortex. AvTx8 inhibited GABA uptake and increased GABA release in the presence of Ca+ , Na+ , and K+ channel blockers, suggesting that it acts directly on GABA transporters. In addition, AvTx8 significantly decreases GABA binding in synaptic membranes from rat brain cortex, suggesting that it also modulates the activity of GABA receptors. Moreover, AvTx8 decreased GAT-1- and GAT-3-mediated GABA uptake in transfected COS-7 cells. Accordingly, we suggest that AvTx8 modulates GABA neurotransmission and might provide a novel entry point for identifying a new class of GABA-modulating neuroprotective drugs.

Properties of the tibialis anterior muscle after treatment with laser therapy and natural latex protein following sciatic nerve crush.

INTRODUCTION: In this study we evaluated the characteristics of the tibialis anterior muscle after sciatic nerve crush and treatment with low-level laser therapy (LLLT) or the protein from natural latex (P1). METHODS: We studied the following 6 groups of male Wistar rats: control (CG); exposed nerve (EG); injured nerve (IG); injured nerve with LLLT (LG); injured nerve with P1 (PG); and injured nerve with P1 and LLLT (LPG). RESULTS: After 4 weeks, muscle morphology showed improvement in the treated groups; after 8 weeks, the treated groups resembled controls, especially the PG. Morphometry revealed muscle fiber atrophy after nerve injury, with time-dependent recovery. Histochemical analysis revealed increased intermediate fiber area. The PG was more similar to controls with NADH staining, whereas the LPG more closely resembled controls with SDH staining. CONCLUSION: Treatment using only P1 proved most efficient, revealing a negative interaction between P1 and LLLT.

Morphometric and high resolution scanning electron microscopy analysis of low-level laser therapy and latex protein (Hevea brasiliensis) administration following a crush injury of the sciatic nerve in rats.

This study evaluated the effect of low-level laser therapy (LLLT; 15 J/cm(2)) and a latex protein (F1) on a crush injury of the sciatic (ischiadicus) nerve. Seventy-two rats (male, 250 g) were divided into 6 groups: CG, control; EG, exposed nerve; IG, injured nerve without treatment; LG, injured nerve with LLLT; HG, injured nerve with F1; and LHG, injured nerve with LLLT and F1. After 4 or 8 weeks, the animals were euthanized and samples of the sciatic nerve were collected for morphometric and high-resolution scanning electron microscopy (HRSEM) analysis. After 4 weeks, the morphometry revealed improvements in the treated animals, and the HG appeared to be the most similar to the CG; after 8 weeks, the injured groups showed improvements compared to the previous period, and the results of the treatment groups were more similar to one another. At HRSEM after 4 weeks, the treated groups were similar and showed improvement compared to the IG; after 8 weeks, the LHG and HG had the best results. In conclusion, the treatments resulted in improvement after the nerve injury, and this recovery was time-dependent. In addition, the use of the F1 resulted in the best morphometric and ultrastructural findings.

Molecular determinants of transport stimulation of EAAT2 are located at interface between the trimerization and substrate transport domains.

Excitatory amino acid transporters (EAATs) regulate glutamatergic signal transmission by clearing extracellular glutamate. Dysfunction of these transporters has been implicated in the pathogenesis of various neurological disorders. Previous studies have shown that venom from the spider Parawixia bistriata and a purified compound (Parawixin1) stimulate EAAT2 activity and protect retinal tissue from ischemic damage. In the present study, the EAAT2 subtype specificity of this compound was explored, employing chimeric proteins between EAAT2 and EAAT3 transporter subtypes and mutants to characterize the structural region targeted by the compound. This identified a critical residue (Histidine-71 in EAAT2 and Serine-45 in EAAT3) in transmembrane domain 2 (TM2) to be important for the selectivity between EAAT2 and EAAT3 and for the activity of the venom. Using the identified residue in TM2 as a structural anchor, several neighboring amino acids within TM5 and TM8 were identified to also be important for the activity of the venom. This structural domain of the transporter lies at the interface of the rigid trimerization domain and the central substrate-binding transport domain. Our studies suggest that the mechanism of glutamate transport enhancement involves an interaction with the transporter that facilitates the movement of the transport domain. We identified a domain (purple star) in the glutamate transporter EAAT2 that is important for transport stimulation through a spider venom, and suggest a mechanism for enhanced transporter function through facilitated substrate translocation (arrow). Because the dysfunction of glutamate transporters is implicated in the pathogenesis of neurological disorders, understanding the mechanisms of enhanced transport could have therapeutic implications.

Morphological and morphometric analyses of crushed sciatic nerves after application of a purified protein from natural latex and hyaluronic acid hydrogel.

Hyaluronic acid hydrogels (HAHs) have been used as a carrier of substances and factors in the repair of nervous tissue. Natural latex protein (Hevea brasiliensis, F1) has shown positive effects in treating various types of tissues, including peripheral nerves. This study evaluated the F1 associated with a HAH in a controlled crush injury (axonotmesis) of the sciatic nerve in Wistar rats. The samples were photomicrographed for morphometric and quantitative analyzes using ImageJ 1.47k software (NIH, Bethesda, MD). Morphological, quantitative (myelin area/nerve area ratio and capillary density) and morphometric (minimum nerve fiber diameter, G-Ratio) data revealed an improvement in the recovery of the sciatic nerve with the application of HAH and the combination of HAH and F1 after 4 and 8 weeks of nerve injury. The most efficacious results were observed with the combination of both substances, F1 and HAH, revealing the regenerative capacity of this new biomaterial, which was hardly tested on nerve tissue.

Elucidating the neurotoxicity of the star fruit.

Caramboxin: Patients suffering from chronic kidney disease are frequently intoxicated after ingesting star fruit. The main symptoms of this intoxication are named in the picture. Bioguided chemical procedures resulted in the discovery of caramboxin, which is a phenylalanine-like molecule that is responsible for intoxication. Functional experiments in vivo and in vitro point towards the glutamatergic ionotropic molecular actions of caramboxin, which explains its convulsant and neurodegenerative properties.

Application of a low-level laser therapy and the purified protein from natural latex (Hevea brasiliensis) in the controlled crush injury of the sciatic nerve of rats: a morphological, quantitative, and ultrastructural study.

This study analyzed the effects of a low-level laser therapy (LLLT, 15 J/cm(2), 780 nm wavelength) and the natural latex protein (P1, 0.1%) in sciatic nerve after crush injury (15 Kgf, axonotmesis) in rats. Sixty rats (male, 250 g) were allocated into the 6 groups (n = 10): CG-control group; EG-nerve exposed; IG-injured nerve without treatment; LG-crushed nerve treated with LLLT; PG-injured nerve treated with P1; and LPG-injured nerve treated with LLLT and P1. After 4 or 8 weeks, the nerve samples were processed for morphological, histological quantification and ultrastructural analysis. After 4 weeks, the myelin density and morphological characteristics improved in groups LG, PG, and LPG compared to IG. After 8 weeks, PG, and LPG were similar to CG and the capillary density was higher in the LG, PG, and LPG. In the ultrastructural analysis the PG and LPG had characteristics that were similar to the CG. The application of LLLT and/or P1 improved the recovery from the nerve crush injury, and in the long term, the P1 protein was the better treatment used, since only the application of LLLT has not reached the same results, and these treatments applied together did not potentiate the recovery.

Sciatic nerve regeneration in rats by a nerve conduit engineering with a membrane derived from natural latex.

PURPOSE: To evaluate the capacity of natural latex membrane to accelerate and improve the regeneration quality of the of rat sciatic nerves. METHODS: Forty male adult Wistar rats were used, anesthetized and operated to cut the sciatic nerve and receive an autograft or a conduit made with a membrane derived from natural latex (Hevea brasiliensis). Four or eight weeks after surgery, to investigate motor nerve recovery, we analyzed the neurological function by walking pattern (footprints analysis and computerized treadmill), electrophysiological evaluation and histological analysis of regenerated nerve (autologous nerve graft or tissue cables between the nerve stumps), and anterior tibial and gastrocnemius muscles. RESULTS: All functional and morphological analysis showed that the rats transplanted with latex conduit had a better neurological recovery than those operated with autologous nerve: quality of footprints, performance on treadmill (p<0.01), electrophysiological response (p<0.05), and quality of histological aspects on neural regeneration. CONCLUSION: The data reported showed behavioral and functional recovery in rats implanted with latex conduit for sciatic nerve repair, supporting a complete morphological and physiological regeneration of the nerve.

Sciatic nerve regeneration in rats by a nerve conduit engineering with a membrane derived from natural latex / Regeneração do nervo ciático em ratos através de um conduto confeccionado com uma membrana de látex natural

PURPOSE: To evaluate the capacity of natural latex membrane to accelerate and improve the regeneration quality of the of rat sciatic nerves. METHODS: Forty male adult Wistar rats were used, anesthetized and operated to cut the sciatic nerve and receive an autograft or a conduit made with a membrane derived from natural latex (Hevea brasiliensis). Four or eight weeks after surgery, to investigate motor nerve recovery, we analyzed the neurological function by walking pattern (footprints analysis and computerized treadmill), electrophysiological evaluation and histological analysis of regenerated nerve (autologous nerve graft or tissue cables between the nerve stumps), and anterior tibial and gastrocnemius muscles. RESULTS: All functional and morphological analysis showed that the rats transplanted with latex conduit had a better neurological recovery than those operated with autologous nerve: quality of footprints, performance on treadmill (p<0.01), electrophysiological response (p<0.05), and quality of histological aspects on neural regeneration. CONCLUSION: The data reported showed behavioral and functional recovery in rats implanted with latex conduit for sciatic nerve repair, supporting a complete morphological and physiological regeneration of the nerve.

OBJETIVO: Avaliar a capacidade de uma membrana de látex natural em acelerar e melhorar a qualidade da regeneração do nervo ciático seccionado de ratos. MÉTODOS: Foram utilizados 40 ratos machos adultos da linhagem Wistar, anestesiados e operados com autoenxerto ou com interposição de um tubo confeccionado com uma membrana derivada do latex natural (Havea brasiliensis). Quatro ou oito semanas após a cirurgia, para investigar a recuperação motora do nervo, foram analisadas a função neurológica através do padrão da marcha (análise das pegadas e esteira computadorizada), avaliação eletrofisiológica e análise histológica do nervo regenerado (enxerto de nervo autólogo ou formação de nervo novo entre os cotos nervosos) e músculos gastrocnêmio e tibial anterior. RESULTADOS: Todas as análises morfológicas e funcionais demonstraram que os ratos transplantados com o conduto de látex tiveram recuperação melhor do que aqueles operados com nervo autólogo: qualidade das pegadas impressas, desempenho em esteira (p<0,01), resposta eletrofisiológica (p<0,05), e qualidade histológica da regeneração nervosa. CONCLUSÃO: Os dados apresentados demonstraram recuperação comportamental e funcional nos ratos implantados com o conduto de látex para a reparação do nervo ciático por meio de uma completa regeneração morfológica e fisiológica do nervo.

Biological evaluation of the bone healing process after application of two potentially osteogenic proteins: an animal experimental model.

OBJECTIVE: The aim of this work was to analyse qualitatively and quantitatively the newly formed bone after insertion of rhBMP-2 and protein extracted from Hevea brasiliensis (P-1), associated or not with a carrier in critical bone defects created in Wistar rat calvarial bone, using histological and histomorphometrical analyses. MATERIALS AND METHODS: Eighty-four male Wistar rats were used, divided into two groups, according to the period of time until the sacrifice (2 and 6 weeks). Each one of these groups was subdivided into six groups with seven animals each, according to the treatments: (1) 5 µg of pure rhBMP-2, (2) 5 µg of rhBMP-2/monoolein gel, (3) pure monoolein gel, (4) 5 µg of pure P-1, (5) 5 µg of P-1/monoolein gel and (6) critical bone defect controls. The animals were euthanised and the calvarial bone tissue removed for histological and histomorphometrical analyses. RESULT AND CONCLUSION: The results showed an improvement in the bone healing process using the rhBMP-2 protein, associated or not with a material carrier in relation to the other groups, and this process demonstrated to be time dependent.

The vegetal biomembrane in the healing of chronic venous ulcers.

BACKGROUND: The vegetal biomembrane has been used to treat cutaneous ulcers. OBJECTIVES: To assess the role of the vegetal biomembrane on the chronic venous ulcers treatment compared to treatment with collagenase cream. METHODS: Fourteen patients were selected to be treated with vegetal biomembrane and 7 with Fibrase(®) (CONTROL), followed clinically and photographically by the Wound Healing Index by ImageJ during 120 days and biopsied on the 1(st) and 30(th) days for histological examination. RESULTS: The vegetal biomembrane was better in promoting healing of the ulcers, especially on the inflammatory phase, confirmed by abundant exudation and wound debridement than the CONTROL group, on the 30th day. There was a greater tendency to angiogenesis followed by re-epithelialization with highest wound healing index on the 90(th) and 120(th) days. CONCLUSION: A combined analysis of clinical and histopathological findings suggests that the vegetal biomembrane acted as a factor inducing wound healing, especially on the inflammatory phase, confirmed by abundant exudation of the lesions promoting the transformation of the microenvironment of the chronic venous ulcers, and also stimulating angiogenesis and subsequent re-epithelialization.

Oral treatment with Hev b 13 prevents experimental arthritis in mice.

Hev b 13 is an allergenic esterase obtained from the rubber tree Hevea brasiliensis, which has been shown recently to induce human monocytes to release interleukin (IL)-10 in vitro, and to exert a potent anti-inflammatory effect in vivo. Moreover, Hev b 13 has been shown to reduce clinical signs of inflammation and also histological damage to the distal colon of mice with 2,4,6-trinitrobenze sulphonic acid (TNBS)-induced colitis after its oral administration. The aim of this study was to investigate the effect of Hev b 13 on human mononuclear cells, as well as its therapeutic use in the methylated bovine serum albumin (mBSA) model of antigen-induced arthritis. Five days before the intra-articular challenge, and daily thereafter for 8 days, Hev b 13 was administered by oral gavage. In mice treated with a dose of 0·5 mg/kg of Hev b 13, the severity of oedema, leucocyte infiltration, pannus formation and cartilage erosion were reduced significantly. These findings underscore the anti-inflammatory activity suggested previously for Hev b 13, an activity speculated to be related to its interaction with monocytes/macrophages and the consequent stimulation of IL-10 release and reduction of tumour necrosis factor (TNF) release. The study also opens a wide range of possible applications in the field of immune-mediated inflammatory diseases.

The vegetal biomembrane in the healing of chronic venous ulcers / Biomembrana vegetal na cicatrização de úlceras venosas crônicas

BACKGROUND: The vegetal biomembrane has been used to treat cutaneous ulcers. OBJECTIVES: To assess the role of the vegetal biomembrane on the chronic venous ulcers treatment compared to treatment with collagenase cream. METHODS: Fourteen patients were selected to be treated with vegetal biomembrane and 7 with Fibrase®(CONTROL), followed clinically and photographically by the Wound Healing Index by ImageJ during 120 days and biopsied on the 1st and 30th days for histological examination. RESULTS: The vegetal biomembrane was better in promoting healing of the ulcers, especially on the inflammatory phase, confirmed by abundant exudation and wound debridement than the CONTROL group, on the 30th day. There was a greater tendency to angiogenesis followed by re-epithelialization with highest wound healing index on the 90th and 120th days. CONCLUSION: A combined analysis of clinical and histopathological findings suggests that the vegetal biomembrane acted as a factor inducing wound healing, especially on the inflammatory phase, confirmed by abundant exudation of the lesions promoting the transformation of the microenvironment of the chronic venous ulcers, and also stimulating angiogenesis and subsequent re-epithelialization.

FUNDAMENTOS: A biomembrana vegetal tem sido usada para tratamento de úlceras cutâneas. OBJETIVOS: Avaliar a ação da biomembrana vegetal no tratamento de úlceras venosas crônicas, comparando-a ao tratamento à base de colagenase. MÉTODOS: Foram selecionados 14 pacientes tratados com biomembrana vegetal e sete com Fibrase® (grupo controle), acompanhados clínico-fotograficamente pelo índice de cicatrização das úlceras (ICU) por 120 dias, por meio do software ImageJ, e biopsiados no primeiro e 30º dias para estudo histopatológico. RESULTADOS: A biomembrana vegetal foi superior em relação ao controle na cicatrização das úlceras no 30º dia, especialmente na fase inflamatória, confirmada pela exsudação abundante e pelo desbridamento. Houve tendência superior à angiogênese seguida de reepitelização com maiores ICUs no 90º e 120º dias. CONCLUSÃO: A análise conjunta dos achados clínicos e histopatológicos sugere que a biomembrana vegetal atuou como um fator indutor da cicatrização, especialmente na fase inflamatória, confirmada pela exsudação abundante das lesões, promovendo a transformação do microambiente das úlceras venosas crônicas e estimulando a angiogênese e a posterior reepitelização.

Implant osseointegration in circumferential bone defects treated with latex-derived proteins or autogenous bone in dog's mandible.

BACKGROUND: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes. PURPOSE: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants. MATERIALS AND METHODS: Ten dogs were submitted to bilateral circumferential defects (5.0 × 6.3 mm) in the mandible. Dental implant (3.3 × 10.0 mm, TiUnite MK3™, Nobel Biocare AB, Göteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor, Osstell AB, Göteborg, Sweden), and bone formation was analyzed by histological and histometric analysis. RESULTS: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p ≥ .05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p ≤ .05). CONCLUSION: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study.

Influence of low-level laser associated with osteogenic proteins recombinant human BMP-2 and Hevea brasiliensis on bone repair in Wistar rats.

This study analyzed the newly formed bone tissue after application of recombinant human BMP-2 (rhBMP-2) and P-1 (extracted from Hevea brasiliensis) proteins, 2 weeks after the creation of a critical bone defect in male Wistar rats treated or not with a low-intensity laser (GaAlAs 780 nm, 60 mW of power, and energy density dose of 30 J/cm(2)). The animals were divided into two major groups: (1) bone defect plus low-intensity laser treatment and (2) bone defect without laser irradiation. The following subgroups were also analyzed: (a) 5 µg of pure rhBMP-2; (b) 5 µg of pure P-1 fraction; (c) 5 µg of rhBMP-2/monoolein gel; (d) 5 µg of P-1 fraction/monoolein gel; (e) pure monoolein gel. Comparisons of the groups receiving laser treatment with those that did not receive laser irradiation show differences in the areas of new bone tissue. The group treated with 5 µg of rhBMP-2 and laser irradiation was not significantly different (P >0.05) than the nonirradiated group that received the same treatment. The irradiated, rhBMP-2/monoolein gel treatment group showed a lower area of bone formation than the nonirradiated, rhBMP-2/gel monoolein treatment group (P < 0.001). The area of new bone tissue in the other nonirradiated and irradiated groups was not significantly different (P > 0.05). Furthermore, the group that received the 5 µg of rhBMP-2 application showed the greatest bone formation. We conclude that the laser treatment did not interfere with the area of new bone tissue growth and that the greatest stimulus for bone formation involved application of the rhBMP-2 protein.

Natural-biomembrane dressing and hypersensitivity.

BACKGROUND: The natural biomembrane of latex extracted from Hevea brasiliensis has been used as a dressing for skin ulcers. OBJECTIVES: To evaluate how safe the natural biomembrane is in relation to hypersensitivity to latex when used as a dressing. METHODS: We selected patients with skin ulcers, forming the following groups: control - low occupational exposure to latex (n = 17); latex-exposed control - high occupational exposure (n = 14); ulcerated, using the natural biomembrane (n = 13); ulcerated control, not using the natural biomembrane (n = 14); and new cases (n = 9), assessed before and after 3 months of using the natural biomembrane. All patients underwent clinical and epidemiological evaluation for latex hypersensitivity and specific IgE (UniCap(®)), and the control and latex-exposed control groups underwent the patch test. RESULTS: Hypersensitivity was positive in 64.7% of the patients in the control group, 71.4% of the patients in the latex-exposed control group, 61.5% of the ulcerated using the natural biomembrane, 35.7% of the ulcerated control, and only 22 , 2% of the new cases. In the patch test of the control and latex-exposed control groups, only one individual in the control group (low contact) showed erythema in the first reading, which became negative in the second. The mean contact with latex in the latex-exposed control group was 3.42 hours / day. In the fluoroimmunoenzymatic assay, most of the sera was classified as zero (range 0-6). No serum was rated above 2, which is not considered significant for hypersensitivity (classification > 4). CONCLUSION: The natural biomembrane proved to be safe as a dressing, for it did not induce hypersensitivity reactions among the volunteers who underwent the patch test or among users of the natural biomembrane, as it was clinically and immunologically demonstrated by IgE levels.