Gamma-hydroxybutyric Acid Tolerance and Withdrawal in a Rat Model

Long-term daily use of gamma-hydroxybutyrate (GHB) and related compounds has recently been associated with a withdrawal syndrome. To the best of the authors' knowledge, there are currently no animal models of GHB withdrawal. OBJECTIVES: The authors studied and described the effect of chronic dosing of GHB (3-6 days) on tolerance and withdrawal in a rat model. METHODS: Rats were administered GHB every three hours via intraperitoneal catheter. Groups of rats (2 per group) were dosed with GHB for either 3 (24 doses), 4 (32 doses), 5 (40 doses), or 6 (48 doses) days. The GHB dose was 0.25 g/kg for doses 1-8, 0.75 g/kg for doses 9-12, 1 g/kg for doses 13-16, 1.25 g/kg for doses 17-24, 1.5 g/kg for doses 25-32, 1.75 g/kg for doses 33-40, and 2 g/kg for doses 41-48. Following the last dose of GHB, the rats were scored using a 16-point ethanol intoxication-withdrawal scale rating spontaneous behaviors, response to handling, grooming, and neurological signs. Lower scores indicate intoxication, while higher scores indicate withdrawal. Scores were recorded at hours 0, 1, 2, 3, 4, 5, 6, 9, 12, and 24. RESULTS: Tolerance: Rats dosed with GHB for more days were less intoxicated one hour after their last GHB dose despite receiving higher doses. WITHDRAWAL: The scores for all rats dosed with GHB increased at hours 4 (p = 0.028), 5 (p = 0.037), 6 (p = 0.007), and 9 (p = 0.024) after the last dose, indicating withdrawal. The scores demonstrated a linear increase dependent upon the number of days of GHB dosing at hours 3 (p < 0.000), 4 (p = 0.004), 5 (p = 0.002), and 12 (p = 0.039) as well as prior to the last dose at hour 0 (p = 0.000). No rats developed seizures. CONCLUSIONS: Tolerance and mild withdrawal in rats can be induced by administering intraperitoneal GHB every three hours for 3-6 days. More prolonged dosing and higher doses of GHB may be necessary to induce severe withdrawal.     

Sternum insufficiency fracture presenting as acute chest pain: a case report and review of the literature.

The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have been rarely reported in an elderly patient. Insufficiency fracture tends to occur in bones with decreased mechanical strength. It tends to occur in elderly patients, especially in postmenopausal women, with underlying diseases. We describe a case of sternum insufficiency fracture in a patient with rheumatoid arthritis and systemic lupus erythematosus on long-term corticosteroid therapy diagnosed in an emergency setting. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other noncardiac and nontraumatic causes of chest pain. If diagnosed accurately, these patients can be discharged and treated as outpatients.     

Revascularized fibula for tibia replacement in adamantinoma

Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile.     

Lugol液染色对食管早期癌和癌前病变的诊断价值

目的 探讨Lugol液染色对食管早期癌和癌前病变的诊断价值。方法 对45例食管黏膜可疑病变经内镜以2％Lugol液喷洒染色，观察黏膜染色情况，并取活检送病理组织学检查。结果 45例食管病变染色后，39例呈浅染色或不染色，其中食管癌8例（食管早期癌5例，进展期癌3例），Barrett食管5例，轻至中度不典型增生1l例。本组Lugol液染色对食管早期癌和癌前病变的检出率达46．7％。结论 内镜下应用Lugol液染色结合活检有助于食管早期癌和癌前病变的诊断，且操作简便，具有重要的临床价值。     

彩色多普勒超声在Graves''''病诊断中的作用

目的:探讨彩色多普勒超声在Graves’病(又称弥漫性甲状腺肿)诊断中的作用。方法:用能量多普勒超声观察40例Graves’病患者及40例正常对照组双侧甲状腺组织的血液供应及分布情况;用脉冲多普勒测量颈总动脉的收缩期峰值流速(VPS),甲状腺上动脉的收缩期峰值流速(VPS)及阻力指数(RI),测量甲状腺上动脉的内径。结果:Graves’病组甲状腺实质内的血供极为丰富,血流分级以Ⅲ级为主,呈“火海征”,Graves’病组与正常对照组相比有显著性差异,P<0.005。Graves’病组颈总动脉的收缩期峰值流速为(162.1±31.5)cm/s,正常对照组颈总动脉的收缩期峰值流速为(98.2±20.9)cm/s,Graves’病组甲状腺上动脉的收缩期峰值流速(108.7±35.6)cm/s,正常对照组甲状腺上动脉的收缩期峰值流速(42.1±15.1)cm/s,以上各参数Graves’病组甲状腺上动脉的阻力指数为0.55±0.11,正常对照组甲状腺上动脉的阻力指数为0.73±0.19。Graves’病组与正常对照组相比有显著性差异P<0.01。Graves’病组甲状腺上动脉的内径为3.34±1.16mm,正常对照组甲状腺上动脉的内径为1.62±1.24mm。Graves’病组与正常对照组相比有显著性差异P<0.01。结论:彩色多普勒超声在Graves’病诊断中有重要的作用。