Sympathoadrenal excitation and inhibition by lower brainstem stimulation in cats

Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM.     

Post-stimulus depression of reflex changes in circular muscle activity in the guinea pig small intestine.

The extent and time course of depression of successive reflex responses recorded with intracellular microelectrodes from the circular smooth muscle of the guinea pig small intestine were determined. Two stimuli were used, distension and distortion of the mucosa by compression; these were applied either at the same or at different sites. Excitatory responses oral and inhibitory responses anal to the stimuli were recorded. Post-stimulus depression of both ascending excitatory and descending inhibitory reflexes occurred, but the extent of depression was slightly less for the descending inhibition. A conditioning distension lasting 9 s depressed the excitatory response to a test distension applied 2 s later at the same site by 90%. After 30 s the depression was 50% and test responses were normal if inter-stimulus intervals were increased to 2 min. Increasing the duration of the conditioning stimulus increased the depression. Post-stimulus depression was less for compression stimuli than for distension stimuli and prior mucosal compression had almost no effect on responses to subsequent distension. The post-stimulus depression was greater if conditioning and test stimuli were at the same rather than different sites. For different sites, conditioning stimuli at 15 mm from the recording site (near) depressed responses to stimuli at 30 mm (far) to a greater extent than far stimuli depressed responses to near stimuli. If the conditioning stimulus at 15 mm was maintained until after the far test stimulus was applied, depression of the test response did not occur. It is concluded that the major sites of post-stimulus depression are at the synapses between primary sensory neurons and the first interneurons of reflex pathways, and that post-stimulus depression also occurs at other places in the pathway, presumably at synapses between interneurons or between interneurons and motor neurons.     

Soluble Fcγ receptors in periodontal lesions

Soluble Fcγ-binding components were detected in gingival fluid from periodontal lesions by incubation with biotinylated human Fcγ fragments. FcγIII receptor was identified by incubation of gingival fluid with monoclonal antibody. Sodium dodecyl sulfate-polyacrylamide gel electophoresis and Western transfer showed that most of the Fcγ-binding components had minimal mobility in a 4–15% gradient gel under nonreducing conditions. Under reducing conditions, the main band of Fcγ-binding components in gingival fluid migrated corresponding to protein A of 49 kDa. The pattern of Fcγ-binding components was similar in serum and gingival fluid except for the observation in gingival fluid of Fcγ-binding components migrating like standard proteins of 19 to 20 kDa, a size that corresponds to the polypeptide part of FcγII receptor and FcγIII receptor.     

肢体不同延长速度对局部血流量的影响

本文报告20只兔胫骨以不同速度延长时用末梢微循环测定系统动态连续监测局部血流量变化的结果,发现一次延长>1 mm时,局部肌肉血流量开始急骤下降,恢复延长前血流量所需的时间>8 h。作者认为肢体的血管、肌肉等组织对1 mm/次/d延长速度有相当大的生物适应性。延长速度>1 mm/次/d易造成局部血流量大幅度减少。延长肢肌肉萎缩、肌力减弱可能与血流量减少有关。     

Rehabilitation of the patient with chronic back pain. A search for outcome predictors

This prospective study was initiated 3 years ago to evaluate the outcome and to identify predictors of success or failure in patients admitted to a rehabilitation program for chronic low-back pain. Multiple parameters were evaluated, including psychologic data (MMPI, personal interview, pain drawing, etc.), physical measurements (flexibility, strength and endurance), and demographic data concerning the patient's home and working environment. Information was available on each patient admitted to the program prior to his admission, at completion of the program, 6 weeks following completion of the program and 3 months following completion of the program. A telephone interview was carried out 2 1/2 years following the patient's discharge from the program. Linear regression analysis was used to identify the important independent variables with regard to the dependent variables of relief of back pain, return to work and increased activities at home. Demographic data were of no value as a predictor with the exception of age and returning to work. The patients over the age of 50 returned to work with much less frequency than those less than 50. Psychologic information from the MMPI and similar tests were of no value. The personal preadmission interview of a trained psychologist, however, was a good predictor of an individual's eventual return to work and overall improvement. Worker's Compensation and other litigation was a negative factor in a patient's prognosis. The treatment team's prognosis at the time of discharge from the program was the best overall predictor of a patient's chance of success or failure in the longterm.     

重症肌无力胸腺切除术后呼吸道管理与并发症的防治

目的 探讨重症肌无力胸腺切除术后呼吸道管理与并发症的防治.方法 32例ICU收治的重症肌无力胸腺切除术后的患者,根据危象预测积分,分为普通组(积分＜12分,n=21)和高危组 (积分＞12分,n=11),对两组患者术后呼吸机支持时间、拔管前后肌力恢复情况、自主呼吸情况、动脉血气分析情况以及两组患者术后体温、胸片和痰培养结果进行统计分析.结果 高危组患者术后呼吸支持时间(18 ～ 30 h,平均26 h)大于普通组患者(4 ～ 28 h,平均14 h),两组有显著性差异(P＜0.01),同时术后发热、胸片渗出影以及阳性痰培养结果的发生率也高于普通组.结论 术后给予高危患者严密的监测和充分的呼吸支持,有助于降低重症肌无力危象的发生率和死亡率,同时应充分重视气道护理和感染的防治.     

Changes in hippocampal neurons and memory function during the developmental stage of newborn rats with hypoxic-ischemic encephalopathy

BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injury, the abnormal functions of brain are varied, and they have very strong plasticity and are corrected easily. OBJECTIVE: To observe the changes of neuronal morphology in hippocampal CA1 region and memory function in newborn rats with hypoxic-ischemic encephalopathy(HIE) from ischemia 6 hours to adult. DESIGN: Completely randomized grouping, controlled experiment. SETTING: Taian Health Center for Women and Children; Taishan Medical College. MATERIALS: Altogether 120 seven-day-old Wistar rats, of clean grade, were provided by the Experimental Animal Center, Shandong University of Traditional Chinese Medicine. Synaptophysin (SYN) polyclonal antibody was provided by Maixin Biological Company, Fuzhou. METHODS: This experiment was carried out in the Laboratory of Morphology, Taishan Medical College between October 2000 and December 2003. ① The newborn rats were randomly divided into 2 groups: model group and control group, 60 rats in each group. Five rats were chosen from each group at postoperative 6 hours, 24 hours, 72 hours, 7 days, 2 weeks and 3 weeks separately for immunohistochemical staining. Fifteen newborn rats were chosen from each group at postoperative 4 weeks and 2 months separately for testing memory ability (After test, 5 rats from each group were sacrificed and used for immunohistochemical staining)② The right common carotid artery of newborn rats of model group was ligated under the anesthetized status. After two hours of incubation, the rats were placed for 2 hours in a container filled with nitrogen oxygen atmosphere containing 0.08 volume fraction of oxygen, thus, HIE models were created; As for the newborn rats in the control group, only blood vessels were isolated, and they were not ligated and hypoxia-treated. ③ Thalamencephal tissue sections of newborn rats of two groups were performed DAB developing and haematoxylin slight staining. Cells with normal nucleous in 250 μm-long granular layer which started from hippocampal CA1 region were counted with image analysis system under high-fold optical microscope (×600), and the thickness of granular layer was measured. The absorbance (A) of positive reactant of SYN in immunohistochemically-stained CA1 region was measured. Learning and memory ability were measured with step through test 3 times successively. ④ t test and paired t test were used for comparing intergroup and intragroup difference of measurement data respectively, and Chi-square for comparing the difference of enumeration data. MAIN OUTCOME MEASURES: Comparison of cytological changes in hippocampal CA1 region and memory ability at different postoperative time points between two groups. RESULTS: Totally 120 newborn rats were involved in the result analysis. ① Cell morphological changes in hippocampal CA1 region: In the control group, with aging, perikaryon, nucleus and nucleolus in cortex of parietal lobe were significantly increased, Nissl body was compacted, the amount of neurons was declined, but the A of SYN positive reactant was relatively increased. In the model group, at postoperative each time point, neurons were seriously shrunk and dark-stained, nucleus was contracted, chromatin was condensed, nucleolus was unclear, even cells disappeared, especially the cells in 6 hours and 24 hours groups. The amount of neurons with normal morphology in hippocampal CA1 region and granular layer thickness in the model group at postoperative each time point were significantly less or smaller than those in the control group at postoperative 6 hours respectively (t =3.002-1.254, P < 0.01). The A value of SYN positive reactant at postoperative 2, 3 and 4 weeks was significantly higher than that at previous time point (t =2.011－2.716,P < 0.05－0.01). ② Test results of learning and memory ability: In the first test, there was no significant difference in the ratio of rats which kept memory ability between two groups (P > 0.05); In the third test, the ratio of rats which kept memory ability in the model group was significantly lower than that in the control group at postoperative 4 weeks and 2 months[53%(8/15)，100%(15/15)；60%(9/15)，93%(14/15)，χ 2=2.863，2.901，P < 0.01]. CONCLUSION: The destroyed hippocampal structure induces the decrease of learning and memory ability of developmental rats. Early interference can increase the quality of neurons and also promote functional development of the nervous system.     

超声诊断异位妊娠249例临床分析

目的为了提高对异位妊娠的诊断技术。方法选择在我院经手术病理证实的异位妊娠249例住院患者行2DB超和CDFI的声像图特征进行分析。结果2D超声声像图特征在249例异位妊娠中内膜增厚223例，厚度为4—8mm／2；宫内假环状孕囊28例，大小为4．12mm；宫外探及孕囊178例，大小为8-48mm；盆腔混合性包块28例，大小为40．80mm：伴有黄体囊肿的123例，存活宫外孕3例，可显示原始心管搏动；CDFI声像图特征为宫外孕急性破裂的患者显示肿块及周围组织的彩色血流信号增多，动脉频谱血流速度增快，RI降低。结论超声检查对妇产科急诊有显著性作用，可直接指导临床明确诊断，选定治疗方案。     

Experimental scoliosis in the rat. II. Biomechanical analysis of the forces during Harrington distraction

The purpose of this study was to characterize the forces resulting from Harrington distraction of the spine in an experimental model of scoliosis in the rat, in order to establish both the similarity of this model to human scoliosis and identify potential force parameters that may be useful for clinical decision-making. Harrington distraction was performed in 36 rats that had been made scoliotic 9-12 weeks earlier by the method described in the previous paper. Distractions were carried out in discrete and timed steps until separation of the vertebral laminae (mechanical failure) occurred at the upper hook site. Distractive forces were monitored continuously by a strain gauge mounted on the tension side of the upper arm of the outrigger. The resulting data were compared among the various curvature groups. The relationship between the length of distraction and the maximum force produced was similar for all animals regardless of curvature. This relationship was quadratic and was characterized by an inflection point where forces increased rapidly with each distraction. The amount of distraction necessary to reach both the inflection and failure points differed only for curves above 100 degrees. The amount of force required to reach failure was lower for curves above 75 degrees. Curves above 50 degrees had a lower percent correction at the inflection point. Bending and tensile forces were calculated by vector analysis. Axial load efficiencies were greater for curves above 50 degrees, as evidenced by increased bending forces in these animals. The viscoelasticity of the spine decreased after inflection in all animals.(ABSTRACT TRUNCATED AT 250 WORDS)     

A cocaine analog and a GBR analog label the same protein in rat striatal membranes.

Because some evidence suggests that cocaine and GBR12935 bind to different sites, we utilized photoaffinity probes from both classes of compounds to see if they label the same protein. [125I]RTI-82 a cocaine analog, and [125I]DEEP, a GBR analog, labeled protein(s) showing the same molecular weight, a similar pharmacological profile and a similar sensitivity to neuraminidase.