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Introduction: We sought to assess the Japanese diet by examining the current dietary intake in Japan using the global reference diet from the EAT-Lancet Commission (Planetary Health Diet; PHD), from the perspective of protein intake in different age groups. Methods: Average dietary intake by food group in the Japan National Health and Nutrition Survey 2019 (NHNS 2019) was converted to the PHD food groups, and the diet gap (DG) (%) of the global reference of the PHD was calculated by age group. Results: Although the DG of the intake was excessive compared with the global reference of the PHD in most food groups in all age groups (7.1-416%), the intake exceeded the upper limit of the range only for red meat (640%). Red meat had the highest DG among subjects in their 40s, although the DG decreased with increasing age. Protein intake was within the possible range and did not greatly exceed the recommended dietary intake in the Japanese standard. Discussion: The current Japanese diet contains an excessive intake of red meat in terms of the global reference of the PHD. This trend is similar to that previously reported in various western regions and countries. However, the Japanese diet does not significantly exceed the recommended protein intake for Japanese people, suggesting that the PHD is an environmentally friendly and healthy choice for younger and older age groups in an aging Japanese society. Policy makers need to develop sustainable and healthy food-based dietary guidelines in addition to providing food and nutrition education and developing a food environment that encourages sustainable and healthy choices to support dietary change.
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The hepatocellular carcinoma (HCC) with intrahepatic and bone metastasis shows poor survival of averagely 3 months. The bone metastasis and HCC itself might cause cancer-associated pain. An intrathecal (IT) analgesia might contribute to improve QOL and prolong surviving time (ST). A 71-year-old male presented with temperature and appetite loss continuing for 2 months. He looked pale and malaise. Computed tomography and tumor markers elevation confirmed diagnosis of HCC stage IV. To treat him, molecularly targeted therapy was started but abandoned because of side effects of life-threatening convulsions and loss of consciousness. Since this time, pain control strategy was planned as advance care plan. After dermal and oral opioids were administered, IT analgesia was introduced to conquer uncontrollable pelvic pain due to metastatic osteolytic lesions. Owing to IT analgesia against severe cancer-related pain, he had lived for 46 months. Comparing with reviews in which average ST is 3 months, this is the case with the longer ST in bone-metastatic HCC. From our experience, it must be emphasized that relieving cancer-related pain strategy for patients with progressive bone-metastatic HCC might contribute to prolong ST longer when adjuvant therapy has been failed.
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INTRODUCTION: Autologous bone grafting or various bone-regenerating materials are used to treat bone defects caused by tumor resection and accident trauma. Octacalcium phosphate, a reasonable bone regenerative material, activates osteoblasts. We fabricated a composite material, octacalcium phosphate/weakly denatured collagen, as a new scaffold. We aimed to investigate the osteoregenerative effect of the octacalcium phosphate/weakly denatured collagen scaffold (compared with that of weakly denatured collagen) in skull defects in a canine model. METHODS: Atelocollagen was extracted from porcine skin via pepsin treatment. The weakly denatured collagen scaffold was fabricated with a freeze-dried and thermally crosslinked atelocollagen suspension at pH 7.4. Octacalcium phosphate was synthesized using Ca-acetate and NaH2PO4. Octacalcium phosphate particles (diameter, 199-298 µm) were mixed with a collagen matrix to fabricate an octacalcium phosphate/weakly denatured collagen scaffold. Bilateral defects (diameter, 10 mm; full-thickness) were induced in dog skulls, and the octacalcium phosphate/weakly denatured collagen and weakly denatured collagen scaffolds were implanted into the defects. RESULTS: Eight weeks after implantations, bone regeneration was evaluated via histopathological analysis. It revealed osteoblast infiltration and osteoregeneration in all defects treated with the octacalcium phosphate/weakly denatured collagen scaffold. The defects treated with weakly denatured collagen scaffold or without any scaffold mostly contained connective tissue, with no neo-osteogenesis. DISCUSSION: The novel octacalcium phosphate/weakly denatured collagen scaffold better promotes osteoregeneration than the weakly denatured collagen scaffold; this "in situ tissue engineering" approach is potentially clinically applicable for bone reconstruction.
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Regeneración Ósea , Trasplante Óseo/métodos , Fosfatos de Calcio/farmacología , Osteogénesis/efectos de los fármacos , Andamios del Tejido , Animales , Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/fisiología , Sustitutos de Huesos/farmacología , Colágeno/farmacología , Perros , Regeneración Tisular Dirigida/métodos , Procedimientos de Cirugía Plástica/métodos , PorcinosRESUMEN
This study introduces the latest progress on the study of artificial sensory organs, with a special emphasis on the clinical results of artificial nerves and the concept of in situ tissue engineering. Peripheral nerves have a strong potential for regeneration. An artificial nerve uses this potential to recover a damaged peripheral nerve. The polyglycolic acid collagen tube (PGA-C tube) is a bio-absorbable tube stuffed with collagen of multi-chamber structure that consists of thin collagen films. The clinical application of the PGA-C tube began in 2002 in Japan. The number of PGA-C tubes used is now beyond 300, and satisfactory results have been reported on peripheral nerve repairs. This PGA-C tube is also effective for patients suffering from neuropathic pain.
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Órganos Artificiales , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos/cirugía , Nervios Periféricos/cirugía , Procedimientos de Cirugía Plástica/métodos , Ingeniería de Tejidos/tendencias , Animales , HumanosRESUMEN
CASE: A 65-year-old man with a completely transected left sciatic nerve at the buttock received an implant with a bioabsorbable nerve conduit over a 20-mm gap. The conduit was filled with collagen to facilitate nerve regeneration. At 4 years after implantation, reinnervation potentials were detected in the muscles, and there was sensory recovery in the reinnervated areas. Thereafter, motor and sensory function recovered gradually over a 14-year period. CONCLUSION: Mixed nerve regeneration after conduit-based reconstruction was demonstrated objectively. Although it took >4 years for motor and sensory functions to be regained, the nerve connection between the buttock and the foot was restored.
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Implantes Absorbibles , Colágeno/administración & dosificación , Regeneración Nerviosa , Nervio Ciático/lesiones , Traumatismos de la Médula Espinal/cirugía , Anciano , Humanos , Masculino , Conducción Nerviosa , Recuperación de la Función , Nervio Ciático/fisiología , Factores de Tiempo , Resultado del TratamientoRESUMEN
OBJECTIVE: Although surgery using a polyglycolic acid-collagen (PGA-c) tube is effective for peripheral nerve injury-induced chronic hand pain, it has not been applied to trigeminal nerve lesions because of the difficult approach. We used a PGA-c tube during surgery for trigeminal neuropathy and evaluated its prognosis based on the outcomes. DESIGN: Case report. SETTING AND PATIENTS: In the dental anesthesia division of a university hospital, 11 patients with severe dysesthesia underwent surgical repair of a damaged lingual nerve (LN) or inferior alveolar nerve (IAN). One patient was lost to follow-up. Changes in quantitative sensory testing (QST) and the presence of dysesthesia as a treatment outcome were compared preoperatively and postoperatively in 10 patients. Two surgical treatments, bridging or encircling peripheral nerves, were applied. Bridging of both stumps was selected when neurotmesis was detected or the nerve was lacerated during surgery (N = 4). Otherwise, a longitudinal PGA-c tube was used to encircle the lesion (N = 6). Outcomes were evaluated 2 months to 8 years postoperatively. RESULTS: Both methods improved the patients' condition based on QST results (brush stroke perception, mechanical touch threshold, sensitivity to cold/hot stimuli). Preoperative allodynia or dysesthesia was resolved in six patients and greatly reduced in four. Two patients (one with inflammation-induced pain, one with implant-related pain) developed prolonged postoperative allodynia requiring pain-relief medication. CONCLUSIONS: Use of a PGA-c tube for surgical treatment of intractable pain due to LN or IAN neuropathy helps alleviate sensory impairment. The possibility of new dysesthesias emerging postoperatively, however, should be noted.
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Traumatismos del Nervio Lingual/cirugía , Nervio Mandibular/cirugía , Dolor Intratable/etiología , Dolor Intratable/cirugía , Enfermedades del Nervio Trigémino/etiología , Adulto , Anciano , Colágeno , Femenino , Humanos , Traumatismos del Nervio Lingual/complicaciones , Masculino , Microcirugia/instrumentación , Microcirugia/métodos , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/instrumentación , Procedimientos Neuroquirúrgicos/métodos , Ácido Poliglicólico , Pronóstico , Resultado del TratamientoRESUMEN
OBJECTIVES/HYPOTHESIS: Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. METHODS: The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients' gustatory function, we measured the patients' electrogustometry (EGM) thresholds. The patients were followed-up for at least two years. RESULTS: Gustatory function was completely restored in all of the patients after the reconstruction. The patients' EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces. CONCLUSION: These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collagen tubes might be useful for repairing CTNs that are resected during middle ear surgery. Further research is required to confirm these preliminary results although this is the first report to describe the successful regeneration of a nerve running through an aerial space.
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Nervio de la Cuerda del Tímpano/fisiopatología , Nervio de la Cuerda del Tímpano/cirugía , Regeneración Tisular Dirigida/métodos , Regeneración Nerviosa , Procedimientos de Cirugía Plástica/métodos , Adolescente , Adulto , Colágeno/química , Femenino , Humanos , Cuidados Intraoperatorios , Masculino , Persona de Mediana Edad , Ácido Poliglicólico/química , Percepción del Gusto , Umbral GustativoRESUMEN
INTRODUCTION: Lingual nerve injury is sometimes caused by dental treatment. Many kinds of treatment have been reported, but many have exhibited poor recovery. Here the authors report changes in somatosensory and chemosensory impairments during a long-term observation after lingual nerve repair. CASE PRESENTATION: A 30-year-old Japanese woman claimed dysesthesia and difficulty eating. Quantitative sensory test results indicated complete loss of sensation in the right side of her tongue. She underwent a repair surgery involving complete resection of her lingual nerve using a polyglycolic acid tube containing collagen 9 months after the injury. A year after the operation, her mechanical touch threshold recovered, but no other sensations recovered. Long-term observation of her somatosensory and chemosensory function after the nerve repair suggested that recovery of taste sensation was greatly delayed compared with that of somatosensory function. CONCLUSION: This case shows characteristic changes in somatosensory and chemosensory recoveries during 7 postoperative years and suggests that taste and thermal sensations require a very long time to recover after repair surgery.
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BACKGROUND: After successful trials of tracheal reconstruction using mesh-type prostheses in canine models, the technique has been applied clinically to human patients since 2002. To enhance tissue regeneration, we have applied a new tissue engineering approach to this mesh-type prosthesis. METHODS: The prosthesis consists of a polypropylene mesh tube reinforced with a polypropylene spiral and atelocollagen layer. The cervical tracheas of 18 beagle dogs were replaced with the prosthesis. The collagen layer was soaked with peripheral blood in 6 of the dogs, with bone marrow aspirate in another 6, and with autologous multipotential bone marrow-derived cells (mesenchymal stem cells) in another 6. The dogs were humanely killed at 1 to 12 months after the operation. RESULTS: All 18 dogs survived the postoperative period. Bronchoscopically, 3 of 4 dogs in the peripheral blood group showed stenosis, whereas no stenosis was evident in all 8 of the dogs in the bone marrow and mesenchymal stem cell groups 6 months after the operation. Faster epithelialization and fewer complications, such as mesh exposure and luminal stenosis, were observed in these two groups than in the peripheral blood group. Histologically, the cells from autologous bone marrow were found to proliferate into the tracheal tissue during the first month. Cilial movement in these two groups was faster than that in the peripheral blood group and recovered to 80% to 90% of the normal level. CONCLUSIONS: Bone marrow aspirate and mesenchymal stem cells enhance the regeneration of the tracheal mucosa on this prosthesis. This in situ tissue engineering approach may facilitate tracheal reconstruction in the clinical setting.
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Prótesis e Implantes , Ingeniería de Tejidos/métodos , Tráquea , Animales , Células de la Médula Ósea/fisiología , Broncoscopía , Proliferación Celular , Cilios/patología , Cilios/fisiología , Colágeno , Perros , Imagen por Resonancia Magnética , Mesodermo/citología , Mesodermo/fisiología , Células Madre Multipotentes , Polipropilenos , Mallas Quirúrgicas , Andamios del Tejido , Tráquea/patología , Tráquea/cirugíaRESUMEN
Adipose-derived stromal cells (ASCs) include stem cells, which have the potential to differentiate into a variety of cell lineages. The regeneration of central nerves was examined using ASCs and a collagen scaffold. A cerebral cortex defect (3 x 4 x 3 mm(3)) was created in the left frontal lobe of 16 male rats. In one group (n = 8), collagen (3 x 4 x 3 mm(3)) seeded with DiI-labeled ASCs was implanted in the defect. In order to seed the ASCs, a combination of the rotary cell culture system and pressing the collagen scaffold gently several times with a glass rod was applied. In the control group (n = 8), collagen was implanted without ASCs. The rats were sacrificed at 1 month after the scaffold implantation. Histologically, 0.2% of the implanted ASCs were positive for anti-human/rat microtubule-associated protein 2 (MAP2) antibody and microvessels were present at a density of 4.6 +/- 1.2/mm(2) within the collagen scaffold-implanted area in each coronal section. In the control group, no MAP2-positive cells were detected and the microvessel density was 0.6 +/- 0.4/mm(2). These data suggest that ASCs seeded into a collagen scaffold may have the potential to promote regeneration of nervous tissue after cerebral cortex injury.
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Diferenciación Celular , Colágeno , Regeneración Nerviosa , Tejido Nervioso/fisiología , Células del Estroma/citología , Ingeniería de Tejidos , Andamios del Tejido , Células Madre Adultas/citología , Células Madre Adultas/fisiología , Animales , Lóbulo Frontal/citología , Grasa Intraabdominal/citología , Masculino , Proteínas Asociadas a Microtúbulos/metabolismo , Ratas , Células del Estroma/fisiologíaRESUMEN
A novel nerve guide tube (poly (L-lactic) acid (PLLA)/ polyglycolic acid (PGA)-c-tube) capable of repairing long peripheral nerve injuries in a canine model has been developed. The tube was created by braiding together PLLA and PGA and then coating it with collagen. PLLA was newly added to the formulation to achieve higher sustainability. The tube was compared with a PGA-collagen tube in clinical use since 2002 having the same structure with a collagen coating but composed of PGA alone (PGA-c-tube). When tested for repair of a 40-mm gap in the left peroneal nerve, using PLLA/PGA-c-tube (n = 15), PGA-c-tube (n = 15), and a negative control group where the cut stump was capped using a silicone cap (n = 15), the lumen structure essential for securing the space for nerve regeneration was maintained in PLLA/PGA-c-tube for over 12 months with a higher number of axons both within the tube and at the distal nerve end. Electrophysiological evaluation revealed that the amplitude of compound muscle action potentials and sensory nerve action potentials after nerve regeneration with PLLA/PGA-c-tube were significantly higher. When assessed using magnetic resonance imaging (MRI), the volume of the tibialis anterior (TA) muscle in dogs that had undergone nerve repair using PLLA/PGA-c-tube was approximately 80% that of the positive control at 12 months. Functional analysis conducted by assessing the ankle angle revealed faster recovery in the PLLA/PGA-c-tube group. Better regeneration was achieved using a PLLA/PGA-c-tube that contains the slowly decomposing fiber material, PLLA. This indicates potential for repair of even longer nerve gaps or defects located near joints, and also clinical application.
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Implantes Absorbibles , Regeneración Tisular Dirigida/instrumentación , Traumatismos de los Nervios Periféricos , Nervios Periféricos/cirugía , Ingeniería de Tejidos/instrumentación , Animales , Perros , Análisis de Falla de Equipo , Regeneración Tisular Dirigida/métodos , Regeneración Nerviosa , Nervios Periféricos/patología , Nervios Periféricos/fisiopatología , Diseño de Prótesis , Terapéutica , Resultado del TratamientoRESUMEN
PURPOSE: Chronic lunotriquetral (LT) instability (persisting >3 months after injury) can be treated with a variety of surgical methods (LT fusion, ligament repair or reconstruction, or arthroscopic debridement), with varying degrees of success. We retrospectively evaluated the results of dorsal capsulodesis using the dorsal radiocarpal ligament in an attempt to reinforce the dorsal LT interosseous ligament in patients with chronic dynamic LT instability. METHODS: A total of 11 patients (mean age, 37 years) with persistent posttraumatic wrist pain and weakness were diagnosed with dynamic LT instability (positive LT ballotment test, disruption of Gilula's lines or volar intercalated segment instability deformity on stress radiography, arthroscopic findings of Geissler grade 3, or 4 LT tears). They were treated consecutively with dorsal capsulodesis. We used subjective and functional outcome measures to evaluate the results. RESULTS: The mean follow-up period was 31 months (range, 12-65 months). The postoperative visual analog pain score and Mayo wrist score were significantly improved compared with their preoperative values. The average grip strength increased by 5 kg, and the average range of wrist flexion was reduced by 3 degrees . CONCLUSIONS: In this small series, in the short term, dorsal radiocarpal ligament capsulodesis reduced pain and instability and improved function in patients with chronic dynamic LT instability. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
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Articulaciones del Carpo/cirugía , Inestabilidad de la Articulación/cirugía , Ligamentos Articulares/cirugía , Hueso Semilunar/cirugía , Procedimientos Ortopédicos/métodos , Hueso Piramidal/cirugía , Adolescente , Adulto , Articulaciones del Carpo/fisiopatología , Femenino , Fuerza de la Mano/fisiología , Humanos , Inestabilidad de la Articulación/fisiopatología , Hueso Semilunar/fisiopatología , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Rango del Movimiento Articular/fisiología , Estudios Retrospectivos , Hueso Piramidal/fisiopatología , Articulación de la Muñeca/fisiopatología , Articulación de la Muñeca/cirugíaRESUMEN
SUMMARY: Over the last 20 years, an increasing number of research articles have reported on the use of artificial nerve tubes to repair nerve defects. The development of an artificial nerve tube as an alternative to autogenous nerve grafting is currently a focus of interest for peripheral nerve repair. The clinical employment of tubes as an alternative to autogenous nerve grafts is mainly justified by the limited availability of donor tissue for nerve autografts and the related morbidity. Numerous studies indicate that short-distance defects in humans can be successfully treated by implantation of artificial nerve guides. This review provides a brief overview of various preclinical and clinical trials conducted to evaluate the utility of artificial nerve tubes for the regeneration of peripheral nerves. This review is also intended to help update hand surgeons on the rapid advances in tubulization techniques, and to provide them with indications of the various directions toward which future research can proceed. Future studies need to provide us with as much comparative information as possible on the effectiveness of different tubulization techniques, in order to guide the surgeon in choosing the best indications for their optimal clinical employment. Future progress in implant development can be expected from interdisciplinary approaches involving both materials and life sciences, leading to advances in neuro-tissue engineering that will be needed to effectively treat larger nerve defects.
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Regeneración Tisular Dirigida/instrumentación , Regeneración Nerviosa/fisiología , Traumatismos de los Nervios Periféricos , Andamios del Tejido , Humanos , Nervios Periféricos/cirugía , Implantación de Prótesis/métodos , Trasplante AutólogoAsunto(s)
Hipoestesia/cirugía , Traumatismos del Nervio Lingual , Nervio Lingual/cirugía , Regeneración Nerviosa , Procedimientos Neuroquirúrgicos/métodos , Adulto , Colágeno , Disartria/etiología , Ingestión de Alimentos , Femenino , Humanos , Hipoestesia/etiología , Prostaglandinas A , Recuperación de la Función , Extracción Dental/efectos adversosRESUMEN
BACKGROUND: Marrow mesenchymal cells are useful in regenerative medicine because they contain stem cells, but there have been few reports of clinical applications. The authors developed a new wound treatment technique by improving marrow mesenchymal cell culture methods and placing cultured cells in an artificial skin material. This new treatment was useful for tissue regeneration in 20 patients with skin wounds. METHODS: Marrow mesenchymal cells from a 46-year-old man were cultured and placed in artificial dermis made of collagen sponge. This composite graft was implanted subcutaneously into the back of a nude mouse and removed 10 days later; immunohistological analysis confirmed regeneration of subcutaneous tissue using human marrow mesenchymal cells. Next, in 20 patients (nine men and 11 women; average age, 64.8 years; range, 22 to 91 years) with intractable dermatopathies, 10 to 20 ml of bone marrow fluid was aspirated from the ilium and cultured in medium containing either fetal calf or autologous serum. The resulting cultured cells were placed in artificial dermis made of collagen sponge, and this composite graft was used to treat skin wounds. RESULTS: The wound mostly healed in 18 of the 20 patients; the remaining two patients died of causes unrelated to transplantation. In all patients, autologous marrow mesenchymal cell transplantation was shown to be therapeutically effective. CONCLUSIONS: In skin regeneration therapy using a marrow mesenchymal cell/artificial dermis composite graft, skin regeneration is possible with bone marrow aspiration, a minimally invasive procedure. Compared with existing skin grafting techniques, the present technique is practical and much less invasive.
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Trasplante de Médula Ósea , Trasplante de Células Madre Mesenquimatosas , Regeneración/fisiología , Heridas y Lesiones/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piel , Piel Artificial , Trasplante Autólogo , Cicatrización de HeridasRESUMEN
OBJECTIVE: After previous success in regenerating canine peripheral nerves over 80 mm gaps using a bioabsorbable nerve guide tube, we have extended this method to the treatment of patients experiencing various types of nerve injury. This report describes the treatment of two cases of motor nerve disorder. METHODS: The bioabsorbable nerve tube was a cylindrically woven polyglycolic acid (PGA) tube filled with collagen. A peripheral motor nerve defect (the frontalis branch of the facial nerve) was reconstructed using this PGA-collagen tube in two patients who experienced posttraumatic unilateral eyebrow ptosis for 3 months. RESULTS: Five months after surgery, both patients regained their ability to voluntarily lift their eyebrows symmetrically. Electrophysiological examination at 5 months revealed recovery of compound muscle action potential and disappearance of distal latency on the affected side. CONCLUSION: This is the first clinical report of motor nerve recovery achieved using the PGA-collagen nerve guide tube. The results suggest that use of a PGA-collagen tube is a promising option for the repair of motor nerve defects.
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Regeneración Tisular Dirigida/instrumentación , Regeneración Tisular Dirigida/métodos , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Nervios Periféricos/cirugía , Ácido Poliglicólico , Prótesis e Implantes , Adulto , Femenino , Humanos , Resultado del TratamientoAsunto(s)
Colágeno , Síndromes de Dolor Regional Complejo/cirugía , Terapia por Estimulación Eléctrica/métodos , Ácido Poliglicólico , Potenciales de Acción/fisiología , Potenciales de Acción/efectos de la radiación , Adulto , Humanos , Masculino , Conducción Nerviosa/fisiología , Conducción Nerviosa/efectos de la radiación , Médula Espinal/fisiopatología , Médula Espinal/efectos de la radiaciónRESUMEN
OBJECTIVE: The feasibility of a nerve guide tube for regeneration of the phrenic nerve with the aim of restoring diaphragmatic function was evaluated in a canine model. METHODS: The nerve tube, made of woven polyglycolic acid mesh, had a diameter of 3 mm and was filled with collagen sponge. This polyglycolic acid-collagen tube was implanted into a 10-mm gap created by transection of the right phrenic nerve in 9 beagle dogs. The tubes were implanted without a tissue covering in 5 of the 9 dogs (group I), and the tubes were covered with a pedicled pericardial fat pad in 4 dogs (group II). Chest x-ray films, muscle action potentials, and histologic samples were examined 4 to 12 months after implantation. RESULTS: All of the dogs survived without any complications. x-ray film examination showed that the right diaphragm was paralyzed and elevated in all dogs until 3 months after implantation. At 4 months, movement of the diaphragm in the implanted side was observed during spontaneous breathing in 1 dog of group I and in 3 dogs of group II. In the dogs showing diaphragm movement, muscle action potentials were evoked in the diaphragm muscle, indicating restoration of nerve function. Regeneration of the phrenic nerve structure was also examined on the reconstructed site using electron microscopy. CONCLUSION: The polyglycolic acid-collagen tube induced functional recovery of the injured phrenic nerve and was aided by coverage with a pedicled pericardial fat pad.
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Colágeno/farmacología , Implantes Experimentales , Nervio Frénico/lesiones , Nervio Frénico/cirugía , Ácido Poliglicólico/farmacología , Animales , Biopsia con Aguja , Modelos Animales de Enfermedad , Perros , Electrofisiología , Inmunohistoquímica , Regeneración Nerviosa/fisiología , Procedimientos Neuroquirúrgicos/métodos , Nervio Frénico/patología , Sensibilidad y EspecificidadRESUMEN
A ferriprotoporphyrin, hemin (Fe(3+)), modified with 3,7,11,15-tetramethyl-2-hexadecen-1-ol, phytol, was adsorbed in nano-spaces of about 4 nm in diameter in mesoporous silica (FSM; folded-sheet mesoporous material) forming a phytol-modified hemin (Fe(3+))-FSM nano-conjugate. The properties and the structure of the conjugate were studied by UV-visible light absorption, IR absorption spectroscopy, and a nitrogen adsorption isotherm. Although the hemin without phytol could not be adsorbed to the mesoporous silica, modification with phytol imparted preferential adsorption properties. The conjugate was not only stable but also had a peroxidase-like activity in a 0.1% hydrogen peroxide solution, while free hemin in the solution was easily destroyed. The hemin (Fe(3+)) in the FSM was reduced to heme (Fe(2+)) by hydrazine. The phytol-modified heme (Fe(2+))-FSM conjugate formed an O(2)-heme complex with a superoxide type structure, resembling oxyhemoglobin or oxymyoglobin, which has not been previously observed for free heme in solution. The addition of carbon monoxide or nitrogen monoxide to the phytol-modified heme (Fe(2+))-FSM conjugate caused the formation of CO- or NO-heme complex in the nano-spaces of the FSM. These properties are attributed not only to the Fe-complex but also to the cooperative functions of the heme with mesoporous silica, resembling properties of a natural heme-protein conjugate; hemoglobin or peroxidase. These results are an elegant example of biomimetic nano-technology.