Response of lumbar paraspinal muscles spindles is greater to spinal manipulative loading compared with slower loading under length control.

BACKGROUND CONTEXT: Spinal manipulation (SM) is a form of manual therapy used clinically to treat patients with low back and neck pain. The most common form of this maneuver is characterized as a high-velocity (duration <150 ms), low-amplitude (segmental translation <2 mm, rotation <4 degrees , and applied force 220-889 N) impulse thrust (high-velocity, low-amplitude spinal manipulation [HVLA-SM]). Clinical skill in applying an HVLA-SM lies in the practitioner's ability to control the duration and magnitude of the load (ie, the rate of loading), the direction in which the load is applied, and the contact point at which the load is applied. Control over its mechanical delivery is presumably related to its clinical effects. Biomechanical changes evoked by an HVLA-SM are thought to have physiological consequences caused, at least in part, by changes in sensory signaling from paraspinal tissues. PURPOSE: If activation of afferent pathways does contribute to the effects of an HVLA-SM, it seems reasonable to anticipate that neural discharge might increase or decrease in a nonlinear fashion as the thrust duration approaches a threshold value. We hypothesized that the relationship between the duration of an impulsive thrust to a vertebra and paraspinal muscle spindle discharge would be nonlinear with an inflection near the duration of an HVLA-SM delivered clinically (<150 ms). In addition, we anticipated that muscle spindle discharge would be more sensitive to larger amplitude thrusts. STUDY DESIGN/SETTING: A neurophysiological study of spinal manipulation using the lumbar spine of a feline model. METHODS: Impulse thrusts (duration: 12.5, 25, 50, 100, 200, and 400 ms; amplitude 1 or 2 mm posterior to anterior) were applied to the spinous process of the L6 vertebra of deeply anesthetized cats while recording single unit activity from dorsal root filaments of muscle spindle afferents innervating the lumbar paraspinal muscles. A feedback motor was used in displacement control mode to deliver the impulse thrusts. The motor's drive arm was securely attached to the L6 spinous process via a forceps. RESULTS: As thrust duration became shorter, the discharge of the lumbar paraspinal muscle spindles increased in a curvilinear fashion. A concave-up inflection occurred near the 100-ms duration eliciting both a higher frequency discharge compared with the longer durations and a substantially faster rate of change as thrust duration was shortened. This pattern was evident in paraspinal afferents with receptive fields both close and far from the midline. Paradoxically, spindle afferents were almost twice as sensitive to the 1-mm compared with the 2-mm amplitude thrust (6.2 vs. 3.3 spikes/s/mm/s). This latter finding may be related to the small versus large signal range properties of muscle spindles. CONCLUSIONS: The results indicate that the duration and amplitude of a spinal manipulation elicit a pattern of discharge from paraspinal muscle spindles different from slower mechanical inputs. Clinically, these parameters may be important determinants of an HVLA-SM's therapeutic benefit.     

子宫腺肌症病变中雌激素、孕激素、癌基因、凋亡抑制基因的表达研究

目的 研究雌激素（ER）、孕激素（PR）及癌基因（cerbB-2）、凋亡抑制基因（Bcl-2）在子宫腺肌症病变中的表达和子宫腺肌症发病的相关性。方法 用免疫组化方法检测40例子宫腺肌症病变组织中ER及其他生物学指标的表达。结果 ER、PR与CerbB．2、Bcl-2在子宫腺肌症病变中均有不同程度的阳性表达，子宫肌层异位内膜ER阳性表达率97．5％，PR阳性率97．5％，cerbB-2阳性率82．5％，Bcl-2阳性率62．5％。在位内膜和异位内膜ER、PR均呈阳性，阳性率比较差异无统计学意义（P〉0．05）。异位内膜cerbB-2的强阳性率高于在位内膜，差异有统计学意义（P〈0．05）。ER、PR与cerbB-2、Bcl-2阳性率相比具有相关性（P〈0．05）。结论 ER、PR与cerbB．2、Bcl-2在异位内膜高表达，提示这些生物学指标在子宫腺肌症发生发展中发挥作用。     

Myasthenia Gravis Appearing After Thymectomy: a Case Report and Review of the Literature

A small proportion of thymoma patients without myasthenia gravis (MG) have been observed to develop MG after total removal of the thymoma. However, the underlying cause is not yet known due to the rarity of postoperative MG patients. We report a 39-year-old man in whom MG appeared after surgical removal of a thymoma. Computed tomography and magnetic resonance imaging showed no signs of recurrent or metastatic thymoma. Administration of pyridostigmine bromide resulted in the prompt improvement of myasthenic symptoms. Our observations indicate that postoperative follow-up care with monitoring of possible postoperative MG is necessary after resecting a thymoma.     

Comparison of the effects of three different combinations of general anesthetics on the electroretinogram of dogs

The objective of this study is to compare the effects of three different anesthetic combinations on the electroretinogram in the same animals under similar laboratory conditions. Thiopental–isoflurane (TI), medetomidine–ketamine (MK), and xylazine–ketamine (XK) were used on each of 12 healthy miniature schnauzer dogs (MS) with a period of at least 3 weeks in between subsequent anesthesia protocols, using the Dog Standard Protocol. The scotopic ERGs consisted of scotopic low stimulus strength (S) responses designated S1, S2, S3, S4, and S5, at 1, 5, 10, 15, and 20 min after dark adaptation, respectively, and scotopic standard stimulus strength (S-ST) responses. The photopic ERGs consisted of a photopic single flash (P) response and 31 Hz flicker (P-FL) responses. For S-ST (2.5 cd s/m²), the amplitude of the a-wave using TI was significantly lower than that using MK (adjusted P = 0.05) and XK (adjusted P = 0.03), and the implicit time of the a-wave was significantly shorter than that using MK (adjusted P = 0.04). For P (2.5 cd s/m²), the amplitude of the b-wave using XK was significantly higher than that using MK (adjusted P = 0.01). The implicit times of the b-wave using TI was significantly longer and shorter than that of MK for S1, S2 and P-FL and for S4 and S-ST, respectively, and than that of XK for S2 and P-FL and for S5 and S-ST, respectively. The results of the present study showed that TI affected both the amplitude and the implicit time of the a-wave for S-ST and the implicit time of the b-wave relatively more so than was the case when using XK or MK. Therefore, it appears that either XK or MK could be advantageous to use rather than TI for clinical studies.     

血管介入仿真模拟器在心血管医生冠状动脉介入技术规范化培训中的作用

目的明确Angiomemor（美国Simbionix公司生产）血管介入仿真模拟器是否有助于冠状动脉造影技术的掌握和提高。方法选取16名无血管放射介入经验的心血管医生，接受相同课时的冠状动脉介入造影理论培训后，按随机表编码随机分为模拟器培训组与非培训组各8名，模拟器培训组8名医生接受Angiomemor血管介入仿真模拟器培训，模拟冠状动脉造影操作，非培训组8名心血管医生未接受仿真模拟器培训。在随后的真实临床环境中操作冠状动脉造影时，评价2组医生冠状动脉造影操作过程中错误的频数、平均造影时间、造影剂使用量及术中放射线剂量。结果相对于非培训组，模拟器培训组医生在冠状动脉造影操作中错误频数减少62．5％、平均造影时间减少44．0％、造影剂使用量减少44．0％，术中平均放射线曝光时间减少了57．7％，平均X线累计曝光剂量减少51．6％，单位面积X线累计曝光剂量减少了52．4％。结论Angiomemor血管介入仿真模拟器有助于医生较快地熟练掌握冠状动脉造影技术，是冠状动脉介入规范化培训的重要辅助手段之一。     

Intraoperative somatosensory evoked potential monitoring during anterior cervical discectomy and fusion in nonmyelopathic patients--a review of 1,039 cases.

BACKGROUND CONTEXT: Intraoperative somatosensory evoked potential (SSEP) monitoring has been shown to reduce the incidence of new postoperative neurological deficits in scoliosis surgery. However, its usefulness during cervical spine surgery remains a subject of debate. PURPOSE: To determine the utility of intraoperative SSEP monitoring in a specific patient population (those with cervical radiculopathy in the absence of myelopathy) who underwent anterior cervical discectomy and fusion (ACDF) surgery. STUDY DESIGN: Retrospective review. PATIENT SAMPLE: A total of 1,039 nonmyelopathic patients who underwent single or multilevel ACDF surgery. The control group (462 patients) did not have intraoperative SSEP monitoring, whereas the monitored group (577 patients) had continuous intraoperative SSEP monitoring performed. OUTCOME MEASURE: A new postoperative neurological deficit. METHODS: SSEP tracings were reviewed for all 577 patients in the monitored group and all significant signal changes were noted. Medical records were reviewed for all 1,039 patients to determine if any new neurological deficits developed in the immediate postoperative period. RESULTS: None of the patients in the control group had any new postoperative neurological deficits. In the monitored group there were six instances of transient SSEP changes (1 due to suspected carotid artery compression; 5 thought to be due to transient hypotension) which resolved with the appropriate intraoperative intervention (repositioning of retractors; raising the arterial blood pressure). Upon waking up from anesthesia, one patient in the monitored group had a new neurological deficit (partial central cord syndrome) despite normal intraoperative SSEP signals. CONCLUSIONS: ACDF appears to be a safe surgical procedure with a low incidence of iatrogenic neurological injury. Transient SSEP signal changes, which improved with intraoperative interventions, were not associated with new postoperative neurological deficits. An intraoperative neurological deficit is possible despite normal SSEP signals.     

Pituitary abscess in a pregnant woman.

Pituitary abscess is a rare and potentially lethal condition. Pituitary abscess in a pregnant woman has not been previously described. A 38-year-old pregnant woman (34 weeks gestation) with a pituitary mass complained of a progressive headache and sudden visual impairment. She was afebrile and had no inflammatory symptoms on admission. On MRI, the preoperative diagnosis was pituitary adenoma with sphenoid sinusitis. She underwent an uncomplicated transsphenoidal procedure for removal of the pituitary mass. The next day, labor commenced and a healthy preterm baby was delivered. Pathologic examination of the intrasellar mass showed polymorphonuclear cells, debris and no tumor cells. The sellar contents were cultured and Streptococcus viridans was grown. To our knowledge this is the first case of pituitary abscess reported during pregnancy. Although the patient was pregnant, the transsphenoidal approach was safe for the mother and the fetus. Surgical drainage and antibiotic therapy are required for the definitive treatment of this condition.     

胆囊癌组织中NDPK／nm23的表达及意义

作者用免疫组化ＡＢＣ法对４１例胆囊癌标本核苷二磷酸激酶（ＮＤＰＫ，下同）／ｎｍ２３表达进行了测定，结果发现：ｎｍ２３在恶性肿瘤中的表达率明显高于良性病变（Ｐ＜０．０５）。ＮＤＰＫ／ｎｍ２３表达与胆囊癌组织的分化、局部浸润及淋巴转移密切相关（Ｐ＜０．０１）。ＮＤＰＫ／ｎｍ２３阳性患者生存中位数１２．２５个月，阴性患者６．５个月，两者存在显著差异（Ｐ＜０．０１），提示ｎｍ２３检测对预后有重要价值。