Efeitos da irradiação com laser de baixa potência nas glândulas salivares submandibulares de ratas diabéticas induzidas por estreptozotocina / Low-power laser irradiation effects in submandibular glands of streptozotocin-induced diabetic rats

O diabetes mellitus (DM) pode levar à disfunção das glândulas salivares. A ativação do receptor de produtos finais de glicosilação avançada e de seus ligantes tem sido reportado em várias doenças crônicas, entre estas, a diabetes e suas complicações. Este estudo analisou a expressão do RAGE, proteína do grupo de alta mobilidade B1 (HMGB1) e de produtos de glicosilação avançada (AGE), bem como os efeitos da irradiação com laser de baixa potência (ILBP) em glândulas salivares submandibulares (GSMs) de ratas diabéticas. Ratas Wistar com 12 semanas de vida foram divididas em 3 grupos: controle (C), diabético (D) e diabético com laser (DL). A indução de DM nos grupos D e DL foi realizada com injeção intraperitoneal de estreptozotocina 60 mg/kg de peso corporal, no 1° dia experimental. No 29°dia, os animais do grupo DL receberam a ILBP (660 nm, 70 mW, 20 J/cm² e 0,56 J por ponto), aplicado no total de quarenta pontos cobrindo a área correspondente as GSMs, e os seus efeitos foram avaliados 24 h após a irradiação (eutanásia). As análises de parâmetros metabólicos, histológicos e de marcadores de inflamação, apoptose e proliferação foram realizadas. Nossos achados mostram que a ILBP diminuiu a glicemia das ratas diabéticas irradiadas, melhorando a resistência à insulina (HOMA-IR), sensibilidade à insulina (HOMA-IS) e função de células beta (HOMA-?). Em GSM, o DM parece aumentar a expressão do eixo HMGB1/AGE/RAGE, possivelmente associado à ativação do fator de transcrição nuclear kappa B (NF?B). A ILBP reduziu os marcadores de inflamação, HMGB1 e TNF-? em GSM de ratas diabéticas, e parece regular a expressão de proteínas relacionadas à proliferação e à apoptose, pela via do AMP cíclico, parcialmente mediado por proteína kinase regulada por sinais extracelulares. No entanto, mais estudos são necessários para melhor entender os efeitos do laser neste tecido.

Diabetes (DM) can lead to dysfunction of the secretory capacity in salivary glands. Since the activation of the receptor for advanced glycation end-products (RAGE) and its ligands has been suggested to participate in chronic disorders, such as diabetes and its complications. This study analyzed the expression of RAGE, high mobility group box protein B1 (HMGB1) and advanced glycation end-products (AGEs) were evaluated, as well as the effects of low-power laser irradiation (ILBP), in diabetic submandibular glands (GSM). Wistar rats 12 weeks-old were divided in three groups: control (C), diabetic (D) and diabetic with laser (DL). The D and DL rats were intraperitoneally injected with streptozotocin 60 mg/kg, in the 1st experimental day. On the 29° day, the DL rats received the ILBP (660 nm, 70 mW, 20 J/cm² e 0,56J per point), with a total of forty points covering the GSMs area, its effects were evaluated 24h after irradiation (euthanasia). Metabolic parameters, histology and the inflammatory, apoptosis and proliferation markers were evaluated. Our findings show that ILBP reduced the blood glucose levels of the irradiated diabetic rats, improving their insulin resistance (HOMA-IR), insulin sensitivity (HOMA-IS) e beta cell function (HOMA-?). In GSM, DM seems to upregulate the expression of HMGB1/AGE/RAGE axis, possibly associated with the activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF?B). The ILBP reduced the inflammatory markers HMGB1 and TNF-? in diabetic GSM, and seems to regulate the expression of proteins related to proliferation and apoptosis, by cyclic AMP pathway, partially mediated by extracellular signal-regulated kinase. However, more studies are necessary to better understand the laser effects on this tissue.

Ineficácia da laserterapia aplicada no trajeto do nervo e nas raízes medulares correspondentes / Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots

Objetivo: Verificar a influência da irradiação do laser de baixa intensidade na regeneração do nervo fibular comum de ratos após lesão por esmagamento. Métodos: Foram utilizados 25 ratos, divididos em três grupos: 1) nervo intacto, e não tratados; 2) nervo lesado, e não tratado; 3) nervo lesado, e laser irradiado sobre a região medular correspondente às raízes do nervo ciático e subsequentemente no trajeto do nervo lesado. A irradiação foi realizada por 14 dias consecutivos. Resultados: Foram avaliados por meio da análise funcional da marcha, através do índice funcional do peroneiro, e por análise morfométrica através do número total de fibras nervosas mielinizadas e sua densidade, número total de células de Schwann, número total de vasos sanguíneos e sua área, diâmetro mínimo da fibra e razão-G. Conclusão: De acordo com a análise estatística, não houve diferença significativa entre os grupos, e os autores concluem que a irradiação do laser de baixa intensidade possui pouca ou nenhuma influência na regeneração nervosa e recuperação funcional. Trabalho experimental.

Objective: To investigate the influence of low intensity laser irradiation on the regeneration of the fibular nerve of rats after crush injury. Methods: twenty-five rats were used, divided into three groups: 1) intact nerve, no treatment; 2) crushed nerve, no treatment; 3) crush injury, laser irradiation applied on the medullary region corresponding to the roots of the sciatic nerve and subsequently on the course of the damaged nerve. Laser irradiation was carried out for 14 consecutive days. Results: animals were evaluated by functional gait analysis with the peroneal functional index and by histomorphometric analysis using the total number of myelinated nerve fibers and their density, total number of schwann cells, total number of blood vessels and the occupied area, minimum diameter of the fiber diameter and G-quotient. Conclusion: according to the statistical analysis there was no significant difference among groups and the authors conclude that low intensity laser irradiation has little or no influence on nerve regeneration and functional recovery. Laboratory investigation.

Efeitos da laserterapia na regeneração nervosa periférica / Effects of laser therapy in peripheral nerve regeneration

OBJETIVO: Analisar o efeito do laser nas doses de 5, 10 e 20J/cm2 na reparação do nervo fibular de ratos após esmagamento. Os resultados foram avaliados por meio da análise funcional da marcha e de parâmetros morfométricos.MÉTODOS: Lesão por esmagamento controlado do nervo fibular comum direito e submetidos a intensidades crescentes (G1: sem irradiação; G2: sham; G3: 5J/cm2; G4: 10J/cm2; G5: 20J/cm2) de irradiação do laser diretamente sobre o local da lesão por 21 dias consecutivos. A análise funcional da marcha foi realizada a intervalos semanais, tendo sido medido o índice funcional do fibular (IFF). Os animais foram sacrificados nos 21º dia pós-operatório para remoção do nervo fibular, que foi preparado para a análise morfométrica.RESULTADOS: Não houve diferença significativa (p>0,05) dos valores da análise de marcha (IFF) entre os grupos em qualquer momento de avaliação para o parâmetro. A área total da secção transversal do nervo foi significantemente maior no grupo 2 do que nos grupos 3 e 4, enquanto a densidade de fibras foi significantemente maior no grupo 4 do que no demais grupos.CONCLUSÃO: A irradiação com o laser AsGaAl de baixa potência não acelerou a regeneração do nervo fibular com nenhuma das doses utilizadas. Nível de Evidência I, Estudos terapêuticos - Investigação dos Resultados do Tratamento.

OBJECTIVE: The influence of dose of low power lasertherapy (AsGaAl, 830 nm) on the regeneration of the fibular nerve of rats after a crush injury was evaluated by means of the functional gait analysis and histomorphometric parameters.METHODS: Controlled crush injury of the right common fibular nerve, immediately followed by increasing doses (G1: no irradiation; G2: simulated; G3: 5 J/cm2; G4: 10 J/cm2; G5: 20 J/cm2) laser irradiation directly on the lesion site for 21 consecutive days. Functional gait analysis was carried out at weekly intervals by measuring the peroneal/fibular functional index (PFI). The animals were killed on the 21st postoperative day for removal of the fibular nerve, which was prepared for the histomorphometric analysis.RESULTS: The PFI progressively increased during the observation period in all groups, without significant differences between them (p>0.05). The transverse nerve area was significantly wider in group 2 than in groups 3 and 4, while fiber density was significantly greater in group 4 than in all remaining groups.CONCLUSION: The low power AsGaAl laser irradiation did not accelerate nerve recovery with any of the doses used. Level of Evidence I, Therapeutic Studies Investigating the Results of Treatment.

Nerve growth factor with fibrin glue in end-to-side nerve repair in rats / Fator de crescimento nervoso em cola de fibrina no reparo término-lateral de nervos em ratos

PURPOSE: To determine the effects of end-to-side nerve repair performed only with fibrin glue containing nerve growth in rats. METHODS: Seventy two Wistar rats were divided into six equal groups: group A was not submitted to nerve section; group B was submitted to nerve fibular section only. The others groups had the nerve fibular sectioned and then repaired in the lateral surface of an intact tibial nerve, with different procedures: group C: ETS with sutures; group D: ETS with sutures and NGF; group E: ETS with FG only; group F: ETS with FG containing NGF. The motor function was accompanied and the tibial muscle mass, the number and diameter of muscular fibers and regenerated axons were measured. RESULTS: All the analyzed variables did not show any differences among the four operated groups (p>0.05), which were statistically superior to group B (p<0.05), but inferior to group A (p>0.05). CONCLUSION: The end-to-side nerve repair presented the same recovery pattern, independent from the repair used, showing that the addition of nerve growth factor in fibrin glue was not enough for the results potentiating.

OBJETIVO: Determinar os efeitos do reparo nervoso término-lateral realizado apenas com cola de fibrina contendo fator de crescimento nervoso em ratos. MÉTODOS: Setenta e dois ratos Wistar foram distribuídos em seis grupos: A - não submetido à secção nervosa; B - secção do nervo fibular (sem reparo); Os outros grupos tiveram o nervo fibular seccionado e então reparado na superfície lateral do nervo tibial intacto, com diferentes procedimentos: C - RNTL com suturas; D - RNTL com suturas e FCN; E - RNTL apenas com CF; F - RNTL com CF contendo FCN. A função motora foi acompanhada e a massa do músculo tibial, o número e o diâmetro das fibras musculares e axônios regenerados foram medidos. RESULTADOS: Não houve diferença entre as variáveis avaliadas nos quatro grupos operados (p>0,05), os quais foram superiores ao grupo B (p<0,05), mas inferiores ao grupo A (p>0,05). CONCLUSÕES: O reparo nervoso término-lateral mostrou o mesmo padrão de recuperação, independente do tipo de reparo utilizado, evidenciando que a adição de fator de crescimento nervoso na cola de fibrina não foi suficiente para a potencialização dos resultados.

Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

OBJECTIVE: There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery. METHOD: A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject. RESULTS: In our cohort, 7 males (23 percent) and 30 females (39 percent) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83 percent) had restless legs after the knee surgeryexclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69 percent) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31 percent) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test. CONCLUSION: Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system.

A irradiação local com o laser de baixa potência acelera a regeneração do nervo fibular de ratos / Local low power laser irradiation accelerates the regeneration of the fibular nerve in rats

OBJETIVO: Estudar a influência da irradiação com o laser AsGaAL de baixa potência na regeneração de um nervo periférico, após lesão por esmagamento controlado. MATERIAL E MÉTODOS: O nervo fibular comum direito de 30 ratos Wistar foi submetido a uma lesão por esmagamento com uma pinça de carga regulável (5.000 g, 10 minutos de aplicação), os animais sendo divididos em três grupos (n=10), de acordo com o procedimento pós-operatório (sem irradiação; irradiação simulada; irradiação efetiva). A irradiação com o laser (comprimento de onda: 830 nm; potência do emissor: 100 mW; modo contínuo; dose: 140 J/cm²) era iniciada no primeiro dia pós-operatório e realizada por 21 dias consecutivos. Foram analisados a massa corporal dos animais, o tempo de percurso na passarela de marcha e o índice funcional do fibular (PFI), pela análise das impressões das pegadas, no período pré-operatório e no 21º dia pós-operatório. RESULTADOS: O tempo de marcha e o PFI melhoraram significativamente mais no grupo de irradiação efetiva com o laser, apesar do ganho significante de massa corporal entre os períodos pré e pós-operatório. CONCLUSÃO: A irradiação com o laser AsGaAL de baixa potência com os parâmetros aqui empregados acelerou e melhorou a regeneração do nervo fibular do rato.

OBJECTIVE: To study the influence of low power GaAs-Al laser irradiation on the regeneration of a peripheral nerve, following a controlled crush injury. MATERIAL AND METHODS: The right common fibular nerve of 30 Wistar rats was submitted to a crush injury with an adjustable load forceps (5 000 g, 10 minutes of application). The animals were divided into three groups (n=10), according to the postoperative procedure (no irradiation; sham irradiation; effective irradiation). Laser irradiation (830 nm wave-length; 100 mW emission power; continuous mode; 140 J/cm²) was started on the first postoperative day and continued over 21 consecutive days. Body mass, time spent on the walking track and functional peroneal index (FPI) were analyzed based the hind footprints, both preoperatively and on the 21st postoperative day. RESULTS: Walking time and PFI significantly improved in the group that received effective laser irradiation, despite the significant gain in body mass between the pre- and post-operative periods. CONCLUSION: Low Power GaAs-Al laser irradiation, with the parameters used in our study, accelerated and improved fibular nerve regeneration in rats.

Experience with peripheral nerve injury in lower extremities

This study reports the results of 43 operations performed on nerves of lower extremities of 43 patients during a period of 7 years from 1999 - 2005 in Mansoura University Hospital and Mansoura Emergency Hospital. There were 15 patients with isolated sciatic nerve injury, 24 with isolated peroneal nerve injury and 4 with isolated tibial nerve injury. All patients were treated with nerve exploration within 1 hour to 7 months after injury and were followed-up for 6 months to 4 years. There were 22 nerve lesions not in continuity [9 needed suture repair and 13 needed sural nerve graft repair], while 21 nerve lesions were in continuity [16 partial lesions needed neurolysis and 5 complete lesions needed neuroma excision and suture repair]. Analysis of the outcome of surgical treatment was performed with respect to the following parameters: period between the injury and operation, patient age, type of injured nerve, mechanism of injury and type of surgical intervention. Overall significant outcome [>/= 3 Louisiana State University Health Science grade] was obtained in 53.5% [sciatic nerve 46%, peroneal nerve 54% and tibial nerve 75%]. According to the type of intervention and lesion categories; lesions not in continuity had a significant outcome 41% [suture repair 55.5% while graft repair 31%], and lesions in continuity had a significant outcome 67% [lesions underwent neurolysis 75%, while lesions underwent suture repair 40%]. Useful function was achieved in 3 [43%] of 7 patients with grafts less than 6 cm in length and in only 1 [16%] of 6 patients with grafts greater than 6 cm in length. The mean time to recovery in patients who underwent surgery was 18 months [range: 1- 32/ ]. In conclusion, the most favourable outcome was obtained with lesions that result in partial lesion in continuity. Considering the rate of spontaneous recovery of post-injection nerve injuries of the sciatic nerve and early onset of skeletal deformities, a closed nerve injury of the lower limb with no recovery within 3 months should always undergo surgery, even if complete functional outcome is not always guaranteed

[Evaluation an altered neurophysiological functions of motor branches of deep peroneal nerve in lateral ankle sprain patients]

Inversion sprain is a result of abnormal forces of plantar flexion and inversion applied to the lateral side of the ankle. This injury recurs in 10% of non-athletes and 80% of athletes. It is believed that Changes in conduction of deep peroneal nerve following inversion sprain and instability occurred following it, to be a cause of recurrence of inversion sprain. Evaluation of the motor branches of deep peroneal nerve in inversion sprain in non-athletes persons is the base of this study. Mechanical instability is assessed through anterior drawer test and talar tilt test and electrical assessment is done first and four weeks after injury in 11 patients in each mechanical instability group of the ankle. All patients had the first incidence of unilateral inversion sprain and normal side was considered as control in the same patient. Electrical assessment of deep peroneal nerve included following: [1] Deep peroneal nerve motor conduction studies in three levels of knee, leg and ankle, [2] Electrical evaluation of tibialis anterior muscle both at rest and minimal contraction. Studies revealed significant changes in temporal dispersion in three levels of knee, below the head of fibula and ankle and motor latency in knee and ankle levels both at the first and second evaluation and motor nerve conduction velocity in leg at the first session in two extremities but no significant difference between mechanical instability was noticed. Also there was a significant difference in recruitment interval of tibialis anterior muscle in comparison of normal and involved extremity and mechanical instability at both sessions. Findings of this study indicated that in lateral ankle sprain deep peroneal nerve incurs is happened and its prognosis is dependent on severity of nerve involvement and grade of instability

Eletroestimulação do músculo tibial cranial após esmagamento do nervo fibular comum: estudo neurofisiológico e morfométrico no rato / Muscle electro stimulation of the cranial tibial muscle after crushing of the common fibular nerve: neurophysiologic and morphometric study in rats

Objetivo: A estimulação elétrica pode ser utilizada após as reparações cirúrgicas a fim de impedir a atrofia muscular enquanto ocorre a regeneração axonal. O objetivo deste trabalho foi avaliar o efeito da eletroestimulação no trofismo muscular após lesão nervosa por esmagamento. Métodos: Foram utilizados 100 ratos, distribuídos em cinco grupos com 20 animais cada. O grupo A foi o de controle de normalidade; o grupo B sofreu lesão no nervo fibular; o grupo C sofreu lesão no nervo fibular e recebeu eletroestimulação diária; o grupo D sofreu lesão no nervo fibular e recebeu eletroestimulação três dias por semana; e o grupo E foi o de controle de desnervação. A estimulação elétrica era realizada, diariamente, durante 60 dias, ao longo de sete minutos, com corrente elétrica contínua, na freqüência de 50 hertz, com duração de 0,5ms e intensidade de 3 volts sobre o músculo tibial cranial direito. Resultados: Os resultados demonstraram ausência de diferença entre os grupos eletroestimulados e não eletroestimulados, evidenciados pelo menor diâmetro e pela contagem do número de fibras musculares assim como pela amplitude do potencial de ação muscular. Conclusão: O modelo experimental de lesão nervosa por esmagamento utilizado nesta pesquisa não foi efetivo para determinar atrofia muscular e a estimulação elétrica, na intensidade e freqüência realizadas, não foi eficiente para alterar o trofismo muscular. O diâmetro mínimo das fibras musculares, a contagem das fibras musculares e a amplitude do potencial de ação muscular foram os atributos mais sensíveis.

Complicaciones en las fracturas complejas de la meseta tibial y factores asociados / Complications in complex fractures of the tibial plateau and associated factors

Objetivo: identificar factores asociados a complicaciones con el manejo quirúrgico de las fracturas complejas de la meseta tibial. Material y métodos: estudio de casos y controles. Muestra integrada con expedientes de 56 pacientes diagnosticados con fractura compleja de la meseta tibial (tipos IV, V y VI de Schatzker), tiempo de seguimiento promedio de 12.9 ± 3.2 meses (8 a 18), y con uno o más de los siguientes factores de riesgo: edad mayor de 50 años, comorbilidad, tiempo de isquemia mayor de 60 minutos y fractura tipo IV, V o VI. Se consideró caso al paciente que presentara una o más complicaciones. Resultados: la edad promedio fue de 50.1 ± 15.7 años (17 a 87); 35 pacientes (62.5 %) pertenecieron al sexo masculino. Los pacientes con o sin complicaciones mostraron homogeneidad respecto a edad, sexo, lado, tipo de fractura y tiempo de seguimiento; 41.1 % presentó antecedentes patológicos. En todos los procedimientos se utilizó torniquete neumático. El tiempo promedio de cirugía fue de 91 ± 27.2 minutos (40 a 175). Los tratamientos empleados fueron placa más tornillos (53.6 %), fijadores externos más tornillos (35.7 %), doble placa y clavo centromedular. 37.5 % desarrolló complicaciones: infección superficial, 16.1 %; deformidades angulares residuales, 10.7 % (varo, 7.1 %); lesión del nervio peroneo, 5.4 %, pseudoartrosis, 3.5 %; trombosis venosa profunda, 1.8 %. Presentó más de una complicación, 22.2 %. Conclusiones: los factores de riesgo asociados significativamente a complicaciones con el manejo de la fractura compleja de la meseta tibial, fueron la edad mayor de 60 años y el tiempo de isquemia transoperatoria mayor de 120 minutos. Los pacientes en estas condiciones presentaron tres veces más riesgo para desarrollar complicaciones.

BACKGROUND: We undertook this study to identify factors associated with surgical complications of complex fractures of the tibial plateau. METHODS: We designed a case-control study with 56 patients with a diagnosis of complex fracture in the tibial plateau (IV-VI Schatzker) and with 12.9 +/- 3.2 (8-18) months of follow-up. Risk factor exposure was defined as having one or more of the following characteristics: age >60 years; co-morbidity (diabetes mellitus, systemic arterial hypertension); time of [quot ]Kidde[quot ] (>60, >90, >120 min) and fracture type IV, V or VI. A case was considered with one or more complications. Results: Mean age was 50.1 +/- 15.7 (17-87) years old; 35 patients (62.5%) were males. Homogeneity between groups was shown for age, sex, side effects, type of fracture and time of follow-up; 41.1% of patients had pathological history. All surgeries used pneumatic compression (Kidde) for 91 +/- 27.2 (40-175) min. The implants used were plate plus cancellous screws (53.6%), external fixators plus cancellous screws (35.7%), double plate and intramedullary nail. Complications appeared in 37.5% of all patients. Complications reported were superficial infection (16.1%), residual angular deformities (10.7%, varum [7.1%]), peroneal nerve injury (5.4%), non-union (3.5%) and deep venous thrombosis (1.8%); 22.2% of all patients presented more than one complication. CONCLUSIONS: Statistically significant risk factors were age >60 years and pneumatic compression >120 min. Patients with one of these characteristics had a three-times risk of complications. No association was demonstrated between type of fracture, surgical treatment, time between injury and the surgery, with development of complications.