RESUMEN
Objective To design two kinds of fixed full-arch implant-supported prosthesis and to investigate their stress distribution in the different vertical heights of the edentulous mandible. Methods The cone-beam computed tomography (CBCT) scan data of the upper denture andmandible were collected to establish the base models of the mandible. The vertical heights of the mandible models were loweredby 0. 5. 10 and 15 mm. and the three-dimensional finite element models of implants with different vertical heights supported by mental foramen 6 parallel implants and supported by “All-on-Four” were established. including 2 groups (8 models); 6-implant group and 4-implant group. A 250 N vertical force was applied to the central fossa of the right mandibular first molar. The stress of each part of the models was analyzed by Ansys 15. 0 software. Results Under the same loading condition. the maximum stress value of the implantswas in the neck of the implants. The maximum stress distribution of 8 models showed that the maximum stress value was 40. 12-49. 06 MPa for the 4-implant group and was 80. 62-109. 64 MPa for the 6-implant group, with the latter being two folds that of the former. In two groups, the maximum stress was the lowest when the vertical height reduction was 5 mm. With the decrease of the mandible vertical height. the stress increased gradually. However, the maximum stress of the 0 mm-height-reduced models was larger than that of 5 mm- height-reducedmodels. Conclusion There is no destructive stress under certain extreme load in both 4-implant group and 6-implant group, with the 4-implant group having a more reasonable stress distribution. The 5 mm-hight-reduced models have the minimum stress, indicating that appropriate vertical height reduction can lead to more reasonable implant stress distribution.
RESUMEN
Objective To investigate the mechanism of invasion of glioma evoked by glutamate.Methods Glioma cell line U251 was cultured in vitro; cell invasion of U251 was detected by Matrigel Transwell method 24 h after 100 μmol/L glutamate treatment; MMP-2 and MMP-9 secretions were detected by gelatin zymography assay 2,4,8 and 12 h afte glutamate treatment; the protein expression of extracellular matrix metalloproteinase inducer (EMMPRIN) was detected by Western blotting 3,6 and 9 h after glutamate treatment. Results Matrigel Transwell method indicated that the cells crossing the cytomembrane of U251 in the glutamate treatment group (37.44±2.31) were significantly increased as compared with those in the control group (25.89±3.00, P＜0.05); MMP-2 secretion in the glutamate treatment group 8 and 12 h afte glutamate treatment was obviously increased as compared with that in the control group (P＜0.05); while Western blotting indicated that no significant differences on the EMMPRIN level were noted between time points of 3, 6 and 9 h after glutamate treatment. Conclusion Glutamate promotes the secretion of MMP-2 in glioma cell line U251 to enhance the invasion of glioma cells; MMP-9 and EMMPRIN are not involved in the process of glutamate promoting the invading of U251.
RESUMEN
Objective To study the relationship between D-wave of thc spinal motor evoked potential and hindlimb motor function status (myodynamia) of rabbits with experimental spinal cord injury. Methods Forty-five rabbits were randomly divided into a control group and 8 injured groups (receiving Allen's injury of50, 75, 100, 125, 150, 175, 200 and 250 gcf, respectively). The myodynamia of hindlimbs and the latency and amplitude of D-wave of the spinal motor evoked potential were recorded right after the injury and in the 4th week of injury, respectively. Simultaneously in the 4th week of injury,the rabbits' spinal sections were stained with neurofilament (NF) immunohistochemistry and their pathological morphologies were observed; and optical densities of NF were measured. Statistic analysis of correlation between myodynamia of hindlimbs and latency and amplitude of D-wave was performed.Results A statistic linear correlation was found between amplitudes declination of D-wave of the spinal motor evoked potential and modified Tarlov's scores right after the injury and in the 4th week of injury (R2=0.98, P＜0.00, regression curve: Y=0.33+4.82X; R=0.99, P＜0.001, regression curve: Y=0.04+0.5 1X),but no statistical correlation was noted between myodynamia and the latency of D-wave of the spinal motor evoked potential at the same time periods(R2=-0.097, P=0.573; R2=-0.165, P=0.337). And the optical density of NF decreased following the amplitude declination of D-wave of the spinal motor evoked potential with linear correlation (R2=0.87, P＜0.001, regression curve: Y= 0.12+0.58X).Conclusion Amplitude declination of D-wave of the spinal motor evoked potential could be used to evaluate the severity of dyskinesia in the injured spinal cord.
RESUMEN
Objective To explore the role of neuroendoscopy in microsurgery in patients with pituitary adenoma via pterional keyhole approach.Methods Thirty-three patients with pituitary adenomas in the sellar region were performed microscope-assisted microsurgery and neuroendoscope-assisted microsurgery via pterional keyhole approach.The data of these patients and the total removal rate of these 2 strategies were analyzed and compared.Results Of the 33 patients,20 achieved total removal of the pituitary adenoma with microscope-assisted microsurgery via pterional keyhole approach and 13 got subtotal removal.Then,these 13 patients were performed neuroendoscope-assisted microsurgery via pterional keyhole approach:total removal was received in 8 and subtotal removal in 5.The total removal percentage that was got under the help of neuroendoscope-assisted microsurgery(28/33)was significantly higher as compared with that using microsurgery(20/33,P<0.05).Conclusion Neuroendoscope-assisted microsurgery via pterional keyhole approach,being able to enlarge the visible field in the microsurgery in patients with pituitary adenoma,increases the complete resection rate,protects the pituitary stalk and decreases the happening of complications.
RESUMEN
Objective To investigate the expression and the role of DCL1 gene in human glioma. Methods Thirty-nine glioma samples and 10 control tissues resected from healthy brain tissue with traumatic brain injury were collected for analysis. Real-time quantitative PCR was employed to detect the DCL1 gene expression at the mRNA level. Plasmid pCS2-DLC1was transfected into the glioma cell line U251 and pCS2-MT was transfected as control group; Western blotting was employed to detect the DCL1 gene expression at the protein level: the expression of Myc; MTT assays were performed to assess the proliferation of glioma cell line U251. Results Glioma tissues showed a significant increased DCL1 gene expression at mRNA level as compared with the control brain tissues (P=0.000). The DLC1 gene expression at mRNA level in the Grade Ⅰ gliomas was obviously higher than that in Grade Ⅱ,Ⅲ or Ⅳ ones (P=0.001). Over-expression of Myc in pCS2-DLC1 transfected group was found, while no obvious Myc expression was noted in the control group. The pCS2-DLC1 transfected group showed higher proliferation level of U251 cell lines than the pCS2-MT control group (P=0.002). Conclusion High expression level of DLC1 might contribute to the formation and development of glioma.
RESUMEN
<p><b>OBJECTIVE</b>To study the relationship between muscle motor evoked potentials (MEP) and hindlimbs motor function in rabbits with spinal cord injury.</p><p><b>METHODS</b>Forty-five rabbits were randomly divided into 9 groups, including one control group and 8 injured groups (receiving Allen's injury of 0, 50, 75, 100, 125, 150, 175, 200, or 250 gcf). Hindlimb strength and muscle MEP were recorded at the 1st day and 4th week postoperatively. At 4 weeks after spinal section, the spinal cord tissue was sampled for histological examination with HE staining and immunohistochemistry with anti-NF antibody of the corticospinal tract fibers.</p><p><b>RESULTS</b>During the operation, MEP showed an all-or-none pattern with significant correlations to postoperative optical density of NF and postoperative hindlimb motor function. The latency prolongation of the muscle MEP at the 4th week showed a linear correlation to the hindlimb Tarlov's score, whereas the MEP amplitude was not correlated to postoperative hindlimb motor function.</p><p><b>CONCLUSIONS</b>The all-or-none pattern of muscle MEP can be used to evaluate the severity of spinal cord injury.</p>
Asunto(s)
Animales , Conejos , Potenciales Evocados Motores , Miembro Posterior , Tractos Piramidales , Traumatismos de la Médula EspinalRESUMEN
Objective To investigate the clinical and neuroimaging features and microsurgical approaches of intracranial cavernous angiomas (CA). Methods The clinical and neuroimaging features and mierosurgical approaches were analyzed retrospectively in 189 cases of intracranial CA. Results Of the 189 cases, 183 presented with CA in the cerebral parenchyma and clinical manifestations including predominantly headache, epilepsy, and hemorrhage, and were managed by radical resection of the CA. The other 6 cases showed intracranial CA in the middle cranial fossa, for which radical CA resection was performed in 5 cases and biopsy in 1 case. Conclusion Microsurgeries are safe and effective for treatment of intracranial CA and may achieve good clinical outcomes.
RESUMEN
Objective To analyze the clinical diagnosis,treatment and prognosis of rhabdoid meningioma.Methods Two cases of rhabdoid meningioma treated in our department were analyzed retrospectively,and the relevant literatures were reviewed.Results Both of the two patients underwent complete meningioma removal under microscope(Simpson grade I)without postoperative radiotherapy or chemotherapy.The two patients were followed up for 2 months and 2 years.One patient experienced meningioma recurred 2 years after the operative,and died due to refusal of a second operation.The other patient died of systemic complications secondary to postoperative intracranial infection.Conclusion The preoperative diagnosis of rhabdoid meningioma can be difficult,and surgical meningioma removal remains the primary choice of treatment.The patients often experience meningioma recurrence shortly after the operation with poor prognosis.Early postoperative radiochemotherapy may prove beneficial in prolonging the survival of patients.
RESUMEN
<p><b>OBJECTIVE</b>To probe into the mechanism of substance-partitioned moxibustion in treatment of primary dysmenorrhea (PD) of cold-damp stagnation type.</p><p><b>METHODS</b>The treatment group (105 cases of PD) were treated with substance-partitioned moxibustion and the control group (104 cases) were treated with Chinese drug Yueyue-shu. Their therapeutic effects were observed. Plasma beta-endorphin contents in menstrual period were determined before and after treatment in 40 patients of each group.</p><p><b>RESULTS</b>The total effective rate of 95.2% in the substance partitioned moxibustion group was better than 85.6% in the control group (P < 0.05); after treatment, plasma beta-endorphin content significantly increased in the substance-partitioned moxibustion group (P < 0.01).</p><p><b>CONCLUSION</b>Substance-partitioned moxibustion has obvious therapeutic effect on primary dysmenorrhea of cold-damp stagnation type, which is carried out possibly through regulating the plasma beta-endorphin content as one of the mechanisms.</p>