Proprioception Analysis following Anterior Cruciate Ligament Reconstruction using Stabilometry: A Prospective, Longitudinal Study / Análise de propriocepção por estabilometria após a reconstrução do ligamento cruzado anterior: Um estudo prospectivo e longitudinal

Abstract Objective Commonly used methods for measuring proprioception have resulted in conflicting reports regarding knee proprioception with anterior cruciate ligament (ACL) rupture and the influence of ACL reconstruction. Methods One hundred subjects (50 patients with radiologically and arthroscopically confirmed unilateral ACL rupture and 50 normal controls) were assessed with regards to proprioception using dynamic single-leg stance postural stabilometry. Instrumented knee ligament laxity and knee outcome scores were also measured. Of the 50 patients in the ACL group, 34 underwent reconstruction and were reassessed postoperatively. Results There was a significant proprioceptive deficiency in the ACL group compared with their contralateral knee ( p < 0.001) and to the control group ( p = 0.01). There was asignificant improvement in knee proprioception following ACL reconstruction compared to preoperative findings ( p = 0.003). There was no correlation between ligament laxity measurements and outcome scores. A significant correlation was found preoperatively between outcome scores and proprioception measurements. This correlation was not found post-operatively. Pre-operative proprioception testing had asignificant correlation (r = 0.46) with post-operative proprioception ( p = 0.006). Conclusion Patients with an ACL rupture had a proprioceptive deficit which improved following ligament reconstruction. Knee outcome scores had a better correlation with proprioception than ligament laxity. Proprioception may be a superior objective measure than ligament laxity in quantifying functional knee deficits and outcomes in patients with ACL ruptures. Level of Evidence III Therapeutic Study; Prospective Longitudinal Case-Control Study.

Resumo Objetivo Os métodos comumente usados para medir a propriocepção resultaram em relatos conflitantes sobre a propriocepção do joelho com ruptura do ligamento cruzado anterior (LCA) e a influência da reconstrução do LCA. Métodos A propriocepção de 100 indivíduos (50 pacientes com ruptura unilateral do LCA confirmada à radiologia e artroscopia e 50 controles normais) foi avaliada por estabilometria postural dinâmica em apoio unipodal. A lassidão ligamentar do joelho instrumentado e suas pontuações de desfechos também foram medidas. Dos 50 pacientes do grupo LCA, 34 foram submetidos à reconstrução e reavaliados no período pós-operatório. Resultados O grupo LCA apresentou deficiência proprioceptiva significativa em relaçãoaojoelho contralateral ( p < 0,001) e ao grupo controle ( p = 0,01). A propriocepção do joelho melhorou de maneira significativa após a reconstrução do LCA em relação aos achados pré-operatórios ( p = 0,003). Não houve correlação entre as medidas de lassidão ligamentar e as pontuações de desfechos. Além disso, observamos uma correlação significativa entre as pontuações de desfechos e as medidas de propriocepção antes da cirurgia. Essa correlação não foi detectada no período pós-operatório. O teste pré-operatório de propriocepção teve correlação significativa ( r = 0,46) com a propriocepção pós-operatória ( p = 0,006). Conclusão Os pacientes com ruptura do LCA apresentaram déficit proprioceptivo que melhorou após a reconstrução ligamentar. As pontuações de desfecho do joelho tiveram melhor correlação à propriocepção do que a lassidão ligamentar. A proprio-cepção pode ser uma medida objetiva superior à lassidão ligamentar na quantificação de déficits funcionais e desfechos do joelho em pacientes com ruptura do LCA. Nível de Evidência III Estudo Terapêutico; Estudo de Caso-Controle Longitudinal Prospectivo.

Analysis of Nerve Endings in the Superior Labrum-Biceps Complex by Fluorescence Immunohistochemistry and Confocal Laser Microscopy / Análise de terminações nervosas no complexo labrum-bíceps superior usando imunohistoquímica de fluorescência e microscopia a laser confocal

Abstract Objectives The capsuloligamentous structures of the shoulder work as static stabilizers, together with the biceps and rotator cuff muscles, increasing the contact surface of the glenoid cavity. Free nerve endings and mechanoreceptors have been identified in the shoulder; however, there are a few studies that describe the presence of these nerves in the biceps' insertion. The present study aimed to describe the morphology and distribution of nerve endings using immunofluorescence with protein gene product 9.5 (PGP 9.5) and confocal microscopy. Methods Six labrum-biceps complexes from six fresh-frozen cadavers were studied. The specimens were coronally cut and prepared using the immunofluorescence technique. In both hematoxylin and eosin (H&E) and immunofluorescence, the organization of the connective tissue with parallel collagen fibers was described. Results In the H&E study, vascular structures and some nerve structures were visualized, which were identified by the elongated presence of the nerve cell. All specimens analyzed with immunofluorescence and confocal microscopy demonstrated poor occurrence of morphotypes of sensory corpuscles and free nerve endings. We identified free nerve endings located in the labrum and in the bicipital insertion, and sparse nerve endings along the tendon. Corpuscular endings with fusiform, cuneiform, and oval aspect were identified in the tendon. Conclusion These findings support the hypothesis that the generation of pain in the superior labral tear from Anterior to posterior (SLAP) lesions derives from the more proximal part of the long biceps cord and even more from the upper labrum. Future quantitative studies with a larger number of specimens may provide more information on these sensory systems.

Resumo Objetivos As estruturas capsulo-ligamentares do ombro funcionam como estabilizadores estáticos, juntamente com os músculos do bíceps e do manguito rotador, aumentando a superfície de contato da cavidade glenoide. Terminações nervosas livres e mecanorreceptores foram identificados no ombro; no entanto, existem alguns estudos que descrevem a presença desses nervos na inserção do bíceps. Este estudo teve como objetivo descrever a morfologia e distribuição de terminações nervosas utilizando imunofluorescência com protein gene product 9.5 (PGP 9.5) e microscopia confocal. Métodos Foram estudados seis complexos labrum-bíceps de seis cadáveres congelados frescos. Os espécimes foram cortados coronalmente e preparados pelo método de imunofluorescência. Tanto em hematoxilina e eosina (H&E) quanto em imunofluorescência, foi descrita a organização do tecido conjuntivo com fibras paralelas de colágeno. Resultados No estudo de H&E, foram visualizadas estruturas vasculares e algumas estruturas nervosas, que foram identificadas pela presença alongada da célula nervosa. Todas as amostras analisadas com imunofluorescência e microscopia confocal demonstraram baixa ocorrência de morfotipos de corpúsculos sensoriais e terminações nervosas livres. Identificamos terminações nervosas livres localizadas no labrum, inserção bicipital e terminações nervosas esparsas ao longo do tendão. Terminais corpusculares com aspecto fusiforme, cuneiforme e oval foram identificados no tendão. Conclusão Esses achados corroboram a hipótese de que a geração de dor nas lesões labrais superiores de anterior a posterior (SLAP, na sigla em inglês) deriva da parte mais proximal do cabo longo do bíceps e ainda mais do labrum superior. Estudos quantitativos futuros com um número maior de espécimes podem fornecer mais informações sobre esses sistemas sensoriais.

Quantification of neural elements in posterior cruciate ligament: comparison between healthy knees and with primary osteoarthrosis / Quantificação dos elementos neurais no ligamento cruzado posterior: comparação entre joelhos hígidos e com osteoartrose primária

ABSTRACT Objective: To quantify the neural elements in the posterior cruciate ligament (PCL) in healthy knees and with primary osteoarthrosis (OA). Methods: In two groups with OA, one of cadavers and another of individuals, the area of neural elements identified in histological sections of PCL with anti-S100 immunohistochemistry was quantified. Results: The overall mean area of the neural elements was 0.96% ± 0.67%, with the value in the cadaver group of 1.02% ± 0.67% and in the OA group of 0.80% ± 0.64%, with a significant statistically difference (p = 0.001). No correlation was observed between neural element quantification and the age of the individuals (p > 0.05). There was no difference in the quantification of neural elements between the sexes in the cadaver group (p = 0.766), but in the OA group there was a statistically significant reduction in males (p = 0.003). Also, in the osteoarthrosis group there was no difference in the quantification of neural elements in the knees with varus or valgus alignment (p = 0.847). Conclusion: There was a decrease in neural element quantification in PCL of individuals affected by OA in relation to non-arthritic individuals, with this quantification not related to age or with the axis of the lower limb. However, this quantification is not related to age or the axis of the lower limb. Level of Evidence III, Case control study.

RESUMO Objetivo: Quantificar os elementos neurais no ligamento cruzado posterior (LCP) em joelhos hígidos e com osteoartrose primária (OA). Métodos: Em um grupo de cadáveres e outro de indivíduos com ao, foi realizada a quantificação da área dos elementos neurais identificados em cortes histológicos do LCP com imunohistoquímica anti-S100. Resultados: A média geral da área dos elementos neurais foi 0,96% ± 0,67%, com o valor no grupo cadáver de 1,02% ± 0,67% e no grupo OA de 0,80% ± 0,64%, havendo uma diferença estatisticamente significante (p = 0,001). Não se observou correlação entre a quantificação dos elementos neurais e a idade dos indivíduos (p > 0,05). Não se observou diferença na quantificação dos elementos neurais entre os sexos no grupo cadáver (p = 0,766), mas no grupo OA se observou redução estatisticamente significante no sexo masculino (p = 0,003). No grupo OA não houve diferença na quantificação dos elementos neurais nos joelhos com alinhamento varo ou valgo (p = 0,847). Conclusão: Foi demonstrada uma redução na quantificação dos elementos neurais no LCP de indivíduos acometidos por OA em relação aos indivíduos não artrósicos, com essa quantificação não tendo relação com idade nem com o eixo do membro inferior. Nível de evidência III, Estudo de caso controle.

Análise dos mecanorreceptores e terminações nervosas livres da banda anterior doligamento glenoumeral inferior com imunofluorescência e microscopia confocal

A banda anterior do ligamento glenoumeral inferior(LGUI), possui uma importante função na estabilidade mecânica do ombro, sendo onsiderado o principal estabilizador estático do ombro, quando o braço encontra-se em abdução e rotação externa. Seis bandas anteriores do LGUI foram cuidadosamente dissecadas para avaliaçãoda morfologiados mecanorreceptorese terminações nervosas livres, buscando compreender a interação do sistema proprioceptivo e mecânico do ombro. Para imunihistoquimica foi utilizado um marcador tipo PGP9.5 (protein gene product)como anticorpo primário e Alexa Fluor 488 como anticorpo secundário, seguido de análise daslâminas pormicroscopia confocal de varredura a laser. Observou-se em todos os ligamentos corpúsculos de Meissnercom diâmetros queentre 30 e 65 μme comprimentos entre 80 e 400 μm,sendo estes descritos pela primeira vez no ligamento glenoumeral inferior;o corpúsculo dePacini, com diâmetro entre 40 e 80 μm e comprimento entre 100 e 180 μme terminações nervosas livres, onde as fibras apresentavam espessura entre 3 e 7 μm e comprimento entre 300 e 700 μm, além de terminações nervosas não classificadas, com formas irregulares, fusiformes e retangulares. Observamos que na banda anterior do ligamento glenoumeral inferior opredomínio de mecanorreceptores de adaptação rápida, tipo Meissner e Pacini. A densidade dos mecanorreceptores foi de aproximadamente 1,1026% ,sendo a densidadede 1,6102% quando a analise foi com profundidade entre 400 e 500 μme de 0,6018%...

The anterior band of the inferior glenohumeral ligament (IGHL) has an important role in the mechanical stability of the shoulder and is considered the main static stabilizer of the shoulder when the arm is in abduction and external rotation. Six anterior bands of IGHL were carefully dissected from the bone attachments to describe the morphology of the mechanoreceptors and free nerve endings and to elucidate the interaction between the proprioceptive system and shoulder mechanics. For immunostaining, a protein gene product 9.5 marker was used as the primary antibody and Alexa Fluor 488 was used as the secondary antibody, followed by image examination using confocal laser scanning microscopy. All the ligament samples contained Meissner corpuscles with a diameter between 30 and 65 μm and length between 80 and 400 μm. This is the first report of these corpuscles in IGHL. Furthermore, these ligaments contained Pacinian corpuscles, with a diameter between 40 and 80 μm and length between 100 and 180 μm, free nerve endings with fiber thickness between 3 and 7 μm and length between 300 and 700 μm, and unclassified nerve endings with irregular, spindle, and rectangular shapes. The mechanoreceptors were approximately 1.2% of the area of the ligament. There was a predominance of Meissner-and Pacini-type rapidly adapting mechanoreceptors.The density ofmechanoreceptorswas approximately 1.1026%, and the densitywhen the analysis was with a depthbetween 400 and 500μmwas 1.6102% and greaterdepthbetween 1500and 1850μm, was 0.6018%...

Different types of additional somatosensory information do not promote immediate benefits on gait in patients with Parkinson's disease and older adults / Diferentes tipos de informação somatossensorial adicional não promovem benefícios imediatos no andar de pacientes com doença de Parkinson e idosos sadios / Diferentes tipos de información somatosensorial adicional no promueven beneficios inmediatos sobre la marcha en pacientes con enfermedad de Parkinson y los mayores saludables

Plantar cutaneous stimulation has been shown to improve gait in Parkinson's disease (PD), but the effects of different types of insoles have not been tested. We evaluated the immediate effect of different types of insoles on gait in PD patients and healthy older adults. Nineteen PD patients and nineteen healthy older adults performed and performed a walking task at their self-selected speed in three conditions: conventional insole, insole with a raised ridge around the foot perimeter, and insole with half-spheres. Plantar sensation was evaluated before and after the walking protocol. There were no differences between groups for plantar sensation before and after the walking task. PD patients demonstrated reduced stride length and stride velocity. There were no immediate benefits offered by the insoles on gait of either group. The increased plantar cutaneous stimulation does not promote immediate benefits on gait in PD patients and healthy older adults.

A estimulação cutânea plantar beneficia o andar de pacientes com doença de Parkinson (DP), mas os efeitos de diferentes tipos de palmilhas ainda não foram testados. Nós avaliamos o efeito imediato de diferentes tipos de palmilhas no andar de pacientes com DP e idosos saudáveis. Dezenove pacientes com DP e dezenove idosos sadios andaram em três condições: palmilha convencional, palmilha com borda na parte externa da superfície do pé e palmilha com semi-esferas. A sensibilidade plantar foi avaliada antes e após o protocolo do andar. Não foram encontradas diferenças entre os grupos para sensibilidade plantar antes e após a tarefa do andar. Os pacientes apresentaram reduzida velocidade e menor comprimento da passada. Não foram verificados benefícios imediatos das palmilhas no andar para os grupos. O aumento na estimulação cutânea plantar não promoveu benefícios imediatos no andar de pacientes com DP e controles.

La estimulación plantar beneficia el andar e de pacientes con enfermedad de Parkinson-(EP), pero los efectos de diferentes tipos de plantillas no fueron testados. Evaluamos el efecto inmediato de diferentes tipos de plantillas en el andar de pacientes con EP y en mayores saludables. Diecinueve pacientes con EP y diecinueve controles fueron evaluados en el andar en tres condiciones: plantilla convencional, plantilla con borde en la superficie exterior del pie e plantilla con semi-esferas. La sensibilidad plantar fue evaluada antes y después de lo andar. No hubo diferencias entre los grupos para la sensibilidad plantar antes y después de lo andar. Los pacientes mostraron velocidad reducida y menor longitud de la zancada. No hubo beneficios inmediatos de las plantillas en el andar para los grupos. El aumento en la estimulación plantar no promovió beneficios inmediatos en el andar para los grupos.

Occlusion on implants---Is there a problem? / 实用口腔医学杂志

Oral rehabilitation restores form and function and impacts on general health.Teeth provide a discriminating sense of touch and directional specificity for occlusal perception,management of food with mastication and swallowing,and awareness of its texture and hard-ness.Peripheral feedback for control of jaw muscles includes the enamel-dentine-pulp complex and mechanoreceptors in the periodontal tis-sues.The implications of feedback from periodontal and other intra-oral mechanoreceptors as well as changes in central representation are significant for function and adaptation to oral rehabilitation.With implants,in the absence of the periodontium and periodontal mechanore-ceptor feedback,fine motor control of mastication is reduced,but patients are still able to function adequately.Further,there is no signifi-cant difference in function with full-arch fixed prostheses on teeth in comparison with implants.Predictable implant outcomes depend on bone support.Optimum restoration design appears to be significant for bone remodelling and bone strains around implants with occlusal loading. Finite element analysis data confirmed load concentrations at the coronal bone around the upper section of the implant where bone loss is com-monly observed clinically.Load concentration increased with steeper cusp inclination and broader occlusal table and decreased with central fossa loading and narrower occlusal table size.It is recommended that occlusal design should follow a narrow occlusal table,with central fossa loading in intercuspal contact and low cusp inclination to minimise lateral loading in function and parafunction.Acknowledging these features should address potential problems associated with the occlusion in implant therapy.

Efecto del bloqueo de canales ionotrópicos voltaje dependiente de calcio sobre las descargas neuronales mecanorreceptivas / Effect of voltage dependent calcium channels block on mechanoreceptive neuronal discharges

El presente trabajo evaluó las modificaciones en los patrones de descarga neuronal mecanoreceptiva inducidas por la nifedipina (inhibidor de canales voltaje-dependientes de calcio tipo L) en el modelo de la pata de la cucaracha P. americana. Se disecaron las patas metatoráxicas de adultos machos, sumergiéndolas en solución Ringer(RIN) o enRinger más nifedipina (100μg.mL-1) por 5 minutos, luego se realizó el registro electrofisiológico durante actividad espontánea (10min) y estimulación mecánica con flexióntibio-femoral (desplazamiento=5mm; aplicación 10s; retiro 10s, por 10min). Los registros multiunitarios se amplificaron y digitalizaron a 11,8KHz. Se analizaron los registros convencionalmente y por procesos puntuales durante laactividad espontánea y con estimulación.Se usó pruebas no paramétricas con significancia en P<0,05. En 44 experimentos con 1000 a 5000 espigas multiunitarias cada uno, se observó quetodas las distribuciones de intervalos interespiga (IIE) se ajustaron a funciones poissonianas, la desviación estándar fue mayor a la media de los IIE,característico de descargas en salvas. No se evidenciaron efectos de la nifedipina sobre los IIE en actividad espontánea (P=0,72) o estimulada (P=0,47), ni sobre los valores de descargas en salvas espontáneas (P=0,32) o estimuladas (P=0,37). Sin embargo, se evidenció una disminución significativa en la frecuencia de descarga del mecanoreceptor durante la fase de inicial de la aplicación del estímulo y un retraso en la fase de adaptación mecanoreceptiva (P<0,001), evidenciando el efecto de la nifedipinay su acción sobre los canales de calcio tipo L en los mecanoreceptores. Esto podría explicar los reportes de pacientes con efectos colaterales durante el uso de la nifedipina en relación a la propiocepción.

Changes of neuronal mechanoreceptive discharge pattern induced by nifedipine (voltage activated L-type calcium channel inhibitor) were evaluatedin the cockroach (P. americana) leg model. Methathoracic legs from male adult insects were dissected and submerged in Ringer solution (RIN) or Ringer with nifedipine (100μg.mL-1) for 5 minutes, thereafter, electrophysiological recordings were made in background activity (10min) and during mechanical tibio-femoral flexion (displacement=5mm; 10s:10s on:off for 10min). Multiunitary recordings were amplified and digitalized at 11.8KHz. Conventional and Point process techniques were used for analysis. Non parametrical test with significance at P<0.05 were used. From 44 experiments with 1000 to 5000 multiunitary spikes recorded on each one, all interspike intervals (ISI) distributions fit to a poissonian function. ISI Standard deviation > ISI arithmetic mean which point out to burst discharges. No evidence of nifedipine effect were found on ISI during background activity (P=0.72) nor mechanical stimulation (P=0.47) not even on burst discharge values (P=0.32 and P=0.37 respectively). However, nifedipine induced a significant reduction on the mechanoreceptor discharge frequency during the early phase of the stimulus and a lengthening of the adaptation phase (P<0.001) which evidences the effect of nifedipine and L-type calcium channel on mechanoreceptors. These could explain sensory and proprioceptive collateral effects reported by patient using nifedipine.

Estrogen Attenuates the Pressor Response Mediated by the Group III Mechanoreflex

PURPOSE: We investigated the effects of group III mechanoreceptors to cardiovascular responses in both pre-menopausal woman and post-menopausal woman during passive ankle dorsiflexion (PAD). METHODS: Twenty healthy volunteers (10 post-menopausal women and 10 pre-menopausal women) were recruited for this study. Stroke volume (SV), heart rate (HR), cardiac output (CO), and total vascular conductances (TVC) were measured continuously throughout the experiment. To stimulate the group III mechanoreceptors, PAD was performed for one minute. RESULTS: The results showed that mean arterial pressure (MAP) mediated by the mechanoreflex activation was significantly increased in both groups. However, this pressor response was significantly higher in post-menopausal women. This reflex significantly increased both SV and CO in pre-menopausal women, while there were no differences in post-menopausal women. There was no difference in HR in either group. The mechanoreflex significantly decreased TVC in post-menopausal woman, while there was no difference in pre-menopausal woman. CONCLUSION: The results indicate that the excessive pressor response mediated by the mechanoreflex occurs due to overactivity of group III mechanorecptors and the mechanism is produced mainly via peripheral vasoconstriction in post-menopausal women.

The effect on the proprioception after Brostr(o)m reconstruction for lateral ankle ligament in rabbit / 中华骨科杂志

ObjectiveTo study the effect on the proprioception after Brostr(o)m reconstruction for lateral ankle ligament in rabbit. MethodsSix-three adult New Zealand white rabbits were used in this study. Nine rabbits were random selected as the blank control group, these rabbits were sacrificed and the lateral ankle ligaments were taken. The rest were all cut the lateral ankle ligament. Twenty-seven rabbits were performed Brostr(o)m reconstruction as the experimental group, and the other were left the apocoptic ligament as the experimental control group. At 2, 6, and 12 weeks after operation, 9 rabbits of each experimental group were sacrificed, and the lateral ligament of ankle were taken randomly for observation. All the lateral ligaments of ankle were stained with a modification of gold-chloride method. We counted the mechanoreceptors under light microscope. ResultsWe identified the four mechanoreceptors: Ruffini receptors, Pacini receptors, Golgi tendon organ-like receptors and free nerve endings, and the first three of them were counted.The amount of mechanoreceptors in blank control group was 21.0±3.5, in experiment group at 2, 6, and 12weeks after operation were 12.7±2.1, 13.0±3.0, and 16.0±2.0 respectively, and in experiment control group was 7.7±1.5, 4.7±1.5, and 6.3±0.6 respectively. The difference among the 2, 6 and 12 weeks after operation in experiment group were statistically significant(F=7.53, P=0.00) and similarly in experiment control group (F=16.27, P=0.00), as time goes on, the amount of mechanoreceptors were increasing gradually. The difference among three group at the 2, 6 and 12 weeks after operation separately were statistically significant (F=88.75, 102.91, 122.53, P=0.00), the amount of mechanoreceptors in experiment group were more than in experiment control group, and lesser than in blank control group. ConclusionAfter rupture of the lateral ankle ligament of rabbit, whether operation or not, the ligament's mechanoreceptors will be decreased. Brostr(o)m anatomical reconstruction for the ruptured ligament can retain the maximum amount of mechanoreceptors.

Relationship of ankle joint proprioceptor injury with chronic ankle instability: a preliminary study / 中华创伤杂志

Objective To analyze the effect of ankle joint proprioceptor injury on the functional ankle instability. Methods The study enrolled 18 ( 13 males) with chronic ankle instability treated with ligament reconstruction operation. The American Orthopaedic Foot and Ankle Surgeons (AOFAS)score was used for evaluation of the function before and after operation and the balance system evaluate the proprioception function. The two ankle ligament specimens from fresh frozen body and the tissue samples from operation were used for investigation of the structure and distribution of the sensory corpuscles by using histology and immunohistoehemical staining. Results The sections were evaluated with a microscope and an image analyzer. Labeled nerve endings were mapped, measured and categorized. Type Ⅰ ( Ruffini-like ending) , type Ⅱ ( Pacinin-like corpuscle ) and type Ⅳ- (noncorpuscular) nerve endings could be identified in all the lateral ankle ligaments, with majority of types Ⅰ and Ⅱ nerve endings.These receptors were distributed primarily over the superficial ligament and near the bony attachments.There was statistical difference between preoperative and postoperative sway distance as well as between preoperative and postoperative AOFAS score. Conclusions This study suggests that the longer history,severer symptoms and lower AOFAS score may lead to the severer injury of the mechanical proprioceptors.The proprioceptor injury is correlated with ankle joint instability and the ligament reconstruction is effective to avoid the repeated injury of the proprioceptor.

Control of respiration in fish, amphibians and reptiles

Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

Training-related changes in the R-R interval at the onset of passive movements in humans

The aim of the present study was to determine whether training-related alterations in muscle mechanoreflex activation affect cardiac vagal withdrawal at the onset of exercise. Eighteen male volunteers divided into 9 controls (26 ± 1.9 years) and 9 racket players (25 ± 1.9 years) performed 10 s of voluntary and passive movement characterized by the wrist flexion of their dominant and non-dominant limbs. The respiratory cycle was divided into four phases and the phase 4 R-R interval was measured before and immediately following the initiation of either voluntary or passive movement. At the onset of voluntary exercise, the decrease in R-R interval was similar between dominant and non-dominant forearms in both controls (166 ± 20 vs 180 ± 34 ms, respectively; P > 0.05) and racket players (202 ± 29 vs 201 ± 31 ms, respectively; P > 0.05). Following passive movement, the non-dominant forearm of racket players elicited greater changes than the dominant forearm (129 ± 30 vs 77 ± 17 ms; P < 0.05), as well as both the dominant (54 ± 20 ms; P < 0.05) and non-dominant (59 ± 14 ms; P < 0.05) forearms of control subjects. In contrast, changes in R-R interval elicited by the racket players' dominant forearm were similar to that observed in the control group, indicating that changes in R-R interval at the onset of passive exercise were not attenuated in the dominant forearm of racket players. In summary, cardiac vagal withdrawal induced by muscle mechanoreflex stimulation is well-maintained, despite long-term exposure to training.

Mecanoreceptores da mucosa palatina de avestruz (Struthio camelus): estudo ao microscópio de luz / Mechanoreceptors of the palatine mucosa of ostrich (Struthio camelus): light microscope study

Foram estudados corpúsculos de Herbst da mucosa palatina de avestruz em nível de microscopia de luz. Os corpúsculos compõem-se de uma cápsula externa, cápsula interna e axônio central. A cápsula externa apresentou numerosas lamelas, enquanto que a cápsula interna mostrou estrutura de folhas compactas. Os corpúsculos apresentaram formato ovalado ou circular e circundado por espessos feixes de fibras colágenas. Cada lamela estava composta de uma densa rede de fibras espessas. Os axônios terminais estavam situados ao longo do eixo, terminando em um bulbo terminal. As fibras da cápsula externa, coradas por Picrosirius e examinadas no microscópio óptico sob luz polarizada, revelou a presença de fibras colágenas do tipo I em verde e na região periférica observou-se grande quantidade de fibras colágenas do tipo III. Os corpúsculos apresentaram-se envoltos por células planas e envoltos por fibras colágenas.

Herbst corpuscles of the palatine mucosa of ostrich were studied by light microscopy. The corpuscles are composed of an outer core, inner core and central nerve terminal. The outer core presents numerous lamellae, while the inner core shows compact structure of cytoplasm sheets. The corpuscles are elongate or oval in shape and are surrounded by bundles of collagen fibers. Each lamella is composed of a dense network of thick fibrils. The terminal axons are located along the axis and form a bulb terminal. The fibers of external core stained by Picrosirius and examined by polarized light microscopy revealed to be green in color like type I collagen fibers, and at the periphery is a large amount of collagen type III. The corpuscles are surrounded by flat cells and dense collagen fibers at the periphery.

The Reflex Effects on the Respiratory Regulation of the CO2 at the Different Flow Rate and Concentration

PURPOSE: The purpose of this study was to investigate the activation of the respiratory centers during insufflation of the larynx with CO2 at different flow rates and concentrations. MATERIALS AND METHODS: The experiments were carried out in spontaneous air breathing rabbits, anesthetized with thiopental sodium (25mg kg(-1) i.v.). The larynx was separated from the oropharyngeal cavity and the trachea. The tidal volume (VT) and respiratory frequency (f min(-1)) were recorded from the lower tracheal cannula. The respiratory minute volume (VE) was calculated, the action potentials from the right phrenic nerve were recorded and the inspiratory (TI) and expiratory (TE) periods and the mean inspiratory flow rate (VT/TI) were calculated. The larynx was insufflated at flow rates of 500mL min(-1) and 750mL min(-1), with 7 and 12% CO2-Air by means of a respiratory pump. RESULTS: Insufflation of the larynx, with both gas mixtures, decreased the f and VT significantly. The TI and TE were found to increase significantly due to the decreasing in f. There was a significant decrease in VT/TI ratio. Following bilateral midcervical vagotomy, on the passing of both gas mixtures, significant decreases were observed in the VT, and the responses of f, TI and TE were abolished. After cutting the superior laryngeal nerve, the responses of the VT to both gas mixtures were abolished. CONCLUSION: In conclusion, the results of this study purpose that the stimulation of the laryngeal mechanoreceptors by the effect of hyper- capnia decreases the activation of the respiratory center

Mechanoreceptors in the Remnants of Ruptured Anterior Cruciate Ligaments in Human Knees / 대한정형외과학회잡지

PURPOSE: This study was performed to identify the presence of mechanoreceptors in the tibial remnants of injured anterior cruciate ligaments (ACLs) in human knees by immunohistochemistry. MATERIALS AND METHODS: Twenty-one specimens of tibial remnants of ACLs from patients with ACL ruptures were obtained during arthroscopic ACL reconstruction procedures. As a control, two normal ACL specimens were taken from healthy men at the time of traumatic above the knee amputations. The ACL specimens were serially frozen-sectioned at a thickness of 40micrometer. The average number of sections from each specimen was 71.5 (total 1,502) in the remnant group and 132 (total 264) in the control group. Immunohistochemical staining was used for detection of the neural elements. The mechanoreceptors were identified under a light microscope and their locations and amounts were recorded. An independent sample t-test was used for analysis. RESULTS: In the remnants of the ACLs, ten mechanoreceptors were identified in 7 (33.3%) out of 21 cases. Nineteen mechanoreceptors were detected in the two normal ACLs, which demonstrated an even distribution at both the tibial and femoral attachments. There was no significant difference between the MR-present group (7 cases) and the MR-absent group (14 cases) with respect to the number of sections, age, and time from injury to surgery. CONCLUSION: The identification of mechanoreceptors in the remnants of ruptured ACL specimens could support the necessity for the preservation of the tibial remnant during ACL reconstruction to improve joint proprioception.

Cases of Swallow Syncope Induced by the Activation of Mechanorecepters in the Lower Esophagus

Swallowing is a rare cause of neurally mediated syncope. The mechanism of swallow syncope that contributes to hypotension, bradycardia, or to both is complex. A 59-year-old man had experienced a recurrent loss of consciousness during swallowing of carbonated beverages or sticky foods. Another 59-year-old man had complained of intermittent syncope just after eating foods. These two patients had no significant structural or functional abnormalities in the esophagus or heart. Both cases showed bradycardia when the lower esophagus was stretched by balloon inflation. The activation of mechanoreceptors in the lower esophagus can be regarded as an initiating factor of these cardioinhibitions. The patients were treated with permanent pacemaker implantation and instructed to change eating habits, respectively.

Changes in the Mechanoreceptors of the Anterior Cruciate Ligament of Patients with Degenerative Arthritis / 대한정형외과학회잡지

PURPOSE: To clarify the morphologic and quantitative changes of mechanoreceptors of the human ACL with degenerative arthritis. MATERIALS AND METHODS: Eleven fresh specimens of anterior cruciate ligament (ACL) were obtained from patients with degenerative arthritis during TKA. As a control, two fresh specimens were taken from healthy men at the time of a traumatic above knee amputation. The whole ligaments were serially frozen and sectioned at a thickness of 40 mum. After immunohistochemical staining, the mechanoreceptors were observed under a light microscope. The ratios of sections showing mechanoreceptors were calculated. Statistical analyses were performed using the chi-square test. RESULTS: In the two control specimens, nineteen mechanoreceptors were found, evenly distributed at the femoral and tibial ends. However, the average number of mechanoreceptors was 1.4 (total 15) in the arthritic ligaments (p<0.05), and these were located near the femoral side rather than the tibial end. The percentage of sections showing mechanorecptors was 8.3% in the arthritic group and 40.2% in the control group (p<0.05). All receptors were round or fusiform shaped Ruffini corpuscles; Pacinian corpuscles could not be found in either group. Nine of 15 mechanoreceptors in the arthritic groups were "necrotic" in shape. CONCLUSION: Mechanoreceptors in arthritic ACL were significantly reduced in number and mainly necrotic in shape. Our findings suggest that the numerical and morphological changes of mechanoreceptors are closely related with reduced proprioception in degenerative arthritis.

Mechanoreceptors in Ligamentum Flavum of Lumbar Spine / 대한척추외과학회지

STUDY DESIGN: Histologic analysis of the ligamentum flavum to determine the distribution of mechanoreceptors in the lumbarspine. OBJECTIVES: To evaluate the distribution of mechanoreceptors in the ligamentum flavum and the quantitative changes according to the presence of degenerative change or segmental instability of the lumbar spine. SUMMARY OF LITERATURE REVIEW: Three types of mechanoreceptors were seen in the ligamentous structures of lumbar spine and they were found mainly in the interspinous/supraspinous ligament complex and the facet joint capsule. The numeric distribution of mechanoreceptors was suggested as the change of proprioception. MATERIALS AND METHODS: The ligamentum flavums were obtained from forty-four patients who underwent surgical decompression for various spinal diseases. The patients were divided into three groups. Group 1(9 cases) was defined as the patients with-out degenerative changes. Group 2(15 cases) included the patients with degenerative changes without instability. In group 3(20cases), the patients had the degenerative changes and instability. The specimens were stained by modified gold-chloride method. The types and numbers of mechanoreceptor were checked in each group and the result was analysed statistically. RESULTS: The total numbers of mechanoreceptors were 2.1+/-1.1, 2.0 +/-1.6, and 0.7+/-0.7 in type 1, 2, and 3. In group 1, the numbers of type 1, 2, and 3 were 2.1+/-0.9, 2.2+/-1.5, and 1.0 +/-0.5, respectively. In group 2, the numbers were 2.0 +/-1.3, 2.0 +/-1.9, and 0.5 +/- 0.6, respectively. In group 3, the numbers were 2.3 +/-1.1, 1.8 +/-1.4, and 0.7 +/-0.8, respectively. Statistically, the numbers of type 1 and type 2 had no difference and were greater than that of type 3. The numbers of type 1, 2, and 3 were not affected according to the presence of degenerative change or instability. CONCLUSION: The mechanoreceptors were seen in ligamentum flavum also as well as interspinous/supraspinous ligament complex and facet joint capsule, and they were mainly slowly or rapidly adapting. The distribution of mechanoreceptors was not affected by the presence of degenerative change or instability. The authors suggest that the degenerative change or instability would not influence to the proprioception of the ligamentum flavum.

The sensation and transduction of mechanical stimulus in cells / 中国病理生理杂志

Mechanical stresses modulate almost all aspects of cell function, including growth, differentiation, migration, gene expression, protein synthesis and apoptosis. Thus, uncovering the mechanisms by which living cells sense and transduce mechanical stress lies at the core of understanding how they respond and adapt to their physical environments. In this review, the possible mechanism about cell response to mechanical stimulus was discussed from outer cell membrane to inner nucleus.