Oral self-administration of etonitazene in rhesus monkeys: Use of a fading procedure to establish etonitazene as a reinforcer

The establishment of orally delivered etonitazene (a potent opioid) as a reinforcer, was studied in eight rhesus monkeys. Initially, when given concurrent access to 2.5 μg/ml etonitazene and the water vehicle, five of the monkeys rejected the drug, whereas the other three monkeys consumed more drug solution than water. The five monkeys that rejected the drug solution underwent an acquisition phase to establish the drug as a reinforcer. A fading procedure was used to transfer control of responding from a 2% (wt/vol) ethanol solution to a 2.5 μg/ml etonitazene solution. Initially, responding was maintained by contingent deliveries of 2% ethanol. Next, across blocks of six or more sessions, increasing amounts of etonitazene were added in steps to the 2% ethanol solution. Subsequently, the 2% ethanol solution was decreased in steps to zero, leaving only the 2.5 μg/ml etonitazene present. When the fading procedure was completed, dose of etonitazene was varied by increasing the volume delivered, first under fixed ratio (FR 4) and then under an FR 8 reinforcement schedule. The same dose manipulations were made with the three monkeys who did not undergo the fading procedure because they preferred etonitazene over water when first tested. Etonitazene was established as a reinforcer for six of the eight monkeys because drug deliveries exceeded vehicle deliveries across a range of drug doses.     

Pyogenic infections of the central nervous system secondary to dental affections—a report of six cases

Pyogenic infections of the central nervous system of dental origin are quite uncommon in industrialized countries. We report six cases with intracerebral (n=4) and intraspinal (n=2) infections treated in our hospital. The microbial pathogen was successfully isolated in all patients. Fusobacterium nucleatum as well as Streptococcus species were found in three cases. Bacillus species were identified in two patients. Actinomyces was the etiologic agent in one case. All patients suffered from dental pathologies, so that after clinical and radiological exclusion of other sources an oral focus was presumed. Therapeutic management consisted of an operative procedure in order to obtain decompression, as well as evacuation of the pus on the one hand, followed by targeted antibiotics on the other. Clinical improvement was achieved in all patients, with one patient lost to follow-up. On magnetic resonance tomography, the inflammatory changes also disappeared in all cases. We recommend that oral infection with recurrent bacteraemia should always be considered in the pathogenesis of the so-called “cryptic” intracerebral and intraspinal infections.     

The relationship between histopathological findings in oral squamous cell carcinoma and FDG uptake on PET

Objectives It is known that, in fluorine-18 fluorodeoxyglucose Positron Emission Tomography (FDG PET) for the diagnosis of oral cancer, FDG uptake may vary even among different cases of the same squamous cell carcinoma. However, the details of this phenomenon have not yet been elucidated. In this study, we analyzed the relationship between histopathological findings in oral squamous cell cancer and PET findings on FDG uptake. Methods We examined 45 patients with oral squamous cell carcinoma who had undergone FDG PET before treatment. FDG uptake was assessed by a standardized uptake value (SUV) calculated according to the PET-measured tissue concentration of FDG, the administered dose of radionuclide, and the body weight of the patient. The relationship between the mean SUV and each of the following parameters was examined: histological grade of malignancy, degree of cell differentiation, size and/or local extent of the primary lesion, and cell density of the tumor. Results The mean SUV of FDG uptake did not depend on the histological grade of malignancy or on the degree of cell differentiation, but tended to be greater the larger the primary lesion. SUV also depended on cell density, increasing with the percentage of tumor parenchyma. Conclusions It is concluded that cancer cell density greatly influences the SUV of FDG, in that a tumor with fewer cellular elements in cancer tissue tends to become a false negative.     

慢性脊髓损伤的实验研究

探讨慢性脊髓损伤的形成原因。方法 选用新西兰白兔36只，随机分为6组，即1天、4月、8月造模组及相应对照组，造模组使用自制捆绑法固定兔于腰椎弯曲位来模仿人类的弯腰运动，通过体感皮层诱发电位及组织形态学等技术进行动态观察。结果 4、8月组造模动物白质出现了髓鞘变薄、水肿，粗大轴突的数量减少，细小的轴突相对增多，诱发电位潜伏期延长等慢性脊髓损伤的病理变化。结论 压迫和牵拉都是造成慢性脊髓损伤的原因。     

Fracture separation of the articular pillar of C5 following brass knuckles trauma

We report the case of a fracture separation of the articular pillar at the lower cervical spine. The trauma, following a brass knuckles, repeats almost in an experimental way the rotation and extension mechanism given in literature for the genesis of such injuries. From the admission in the orthopaedic service to the surgery, the development went in a characteristic way towards a rotatory displacement. Received: 12 July 2002, Accepted: 18 August 2002 Correspondence to: R. Massicot     

Evidence for a reflex provoking contraction of the renal pelvis (with some comments on its clinical implications)

The effect of swallowing a small quantity of water or of solid food (biscuit) on the renogram curve was observed in 177 patients. Swallowing provoked contraction of the renal pelvis in 63% of the kidneys with a pelvicalyceal system which was neither obstructed nor dilated, with expulsion of a substantial fraction of the contents within 30 s. This did not occur in obstructed or denervated kidneys, nor in patients with a high transection of the spinal cord. Evidence is adduced that this contraction is mediated reflexly. This effect may be used diagnostically to distinguish physiological dilatation from obstruction. The implications when performing and interpreting renography are discussed. Correspondence to: M.V. Merrick     

沈阳市961名老年干部牙健康状况调查

目的了解并分析沈阳市老年干部牙健康状况。方法按第二次全国口腔健康流行病学抽样调查标准,对沈阳市961名60岁以上的老年干部进行口腔健康调查,结果用SPSS软件处理。结果患龋率为67.12%,患龋者的龋均随着年龄的增长而逐渐增高(P<0.05),龋齿全部充填率为33.18%。缺牙率为80.65%,人均失牙7.38颗,人均保留牙的数目与年龄呈负相关(P<0.01)。无牙牙合率为10.20%,无牙牙合与牙列缺损的修复率分别为98.98%和36.04%。牙周健康状况与年龄呈负相关(P<0.01)。结论牙列缺失及缺损是老年人常见的口腔疾患,龋病和牙周病是其主要原因。加强老年人的口腔保健意识,是提高口腔疾病治疗成功率的重要环节,进而增进老年人的全身健康。     

Intrahippocampal Injection of Endothelin-1: A New Model of Ischemia-induced Seizures in Immature Rats

Summary:  The goal of this study was to develop a new model of ischemia-induced seizures in immature rats using injection of vasoconstrictor Endothelin-1 (ET-1) into the brain. ET-1 (10, 20, or 40 pmol) was infused into the left dorsal hippocampus of freely moving Wistar rats 12 (P12) and 25 (P25) days old. Animals were then video/EEG-monitored for 100 min and monitoring was repeated 22 h later. Parameters of electrographic seizures (frequency and mean duration) as well as pattern of their behavioral correlates were evaluated. The pattern of behavioral seizures was used to develop model-specific scoring system. Cresyl violet and Fluoro Jade-B-staining were used to evaluate brain damage. Extension of the lesion was correlated with seizure severity. After ET-1-injection, seizures occurred in 83–100% animals of all age-and-dose groups and persisted for 24 h except P12 rats with 10 pmol. There were no differences in average seizure duration (18–40 s) or seizure frequency (3–7 seizures/100 min) among individual dose-groups. Between the 1st and 2nd observation period, total seizure duration decreased in 71% of P12 and 47% of P25 rats. Electrographic seizure activity was most frequently accompanied by clonus, incidence of more severe convulsions (barrel rolling or generalized clonic seizures) increased with dose of ET-1. Morphologic examination did not reveal any dose-related difference in damage severity, hippocampal damage was however more extensive in P12 compared to P25 animals. Seizure severity correlated positively with severity of the damage in both age groups. Our study presents focal injection of ET-1 into the brain as a new and practical model of ischemia-induced seizures in immature rats.     

明显强化孤立肺结节血流模式的临床价值

目的利用4层螺旋CT动态增强技术定量评价不同性质的明显强化孤立肺结节的血流模式并初步评价血管内皮生长因子(VEGF)表达阳性的孤立性肺腺癌血管生成与血流模式定量CT参数的相关性.方法 78例孤立明显强化肺结节(直径≤4 cm,68例恶性,10例活动性炎性),行多层螺旋CT(MSCT)动态增强(以4 ml/s的流率注入对比剂).记录孤立肺结节增强前后各时相的CT值并计算强化值、灌注值,结节-主动脉强化值比.灌注值等于时间-密度曲线最大斜率除以主动脉强化值.其中30例VEGF表达阳性的肺腺癌患者用免疫组织化学测定微血管密度(MVD)并标定VEGF,评价肺腺癌血流模式定量CT参数(强化值、灌注值、结节-主动脉强化值比及平均通过时间)与MVD的相关性.结果恶性结节强化值(35.79±10.76) HU与活动性炎性结节(39.76±4.59) HU差异无显著意义 (t=1.148 , P=0.255).恶性结节的结节-主动脉强化值比(14.27±4.37)%及灌注值(3.02±0.96)ml-1·min-1·kg-1均低于活动性炎性结节(18.51±2.71)%,(6.34±4.39)ml-1·min-1·kg-1 (t=2.978,P=0.004;t=5.590,P<0.0001).VEGF表达阳性的肺腺癌强化值(33.06±13.57)HU、结节-动脉强化值比(14.25±4.92)%及灌注值(2.97 ±0.56) ml-1·kg-1·min-1与MVD(70.15±20.03)条/视野,均呈正相关性(r=0.781, P<0.0001;r=0.688, P<0.0001;r=0.716, P<0.0001).平均通过时间(14.86±5.84)s与MVD无显著相关性(r=0.260, P=0.200).结论恶性与活动性炎性孤立肺结节血流模式不同,恶性结节通过结节-大动脉强化值比和灌注值可有效区别于活动性炎性结节,有助于两者鉴别诊断.肺腺癌强化值、结节-动脉强化值比及灌注值反映了VEGF表达阳性的肺腺癌的MVD.强化值、结节-动脉强化及灌注值可作为VEGF相关的肺腺癌血管生成的指标.