Long-term high-fat diet inhibits hippocampal expression of insulin receptor substrates and accelerates cognitive deterioration in obese rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effect of long-term high-fat diet on the expressions of insulin receptor substrates in the hippocampus and spatial learning and memory ability of obese rats.</p><p><b>METHODS</b>A total of 100 4-week-old male SD rats were randomly divided into two groups and fed with common diet (CD group, n=40) or high-fat diet (HFD group, n=60) for 16 weeks. At 4, 8, 12, 16 and 20 weeks, 8 rats were randomly selected from each group for testing their spatial learning and memory function using Morris water maze. After the tests, the rats were sacrificed for measurement of the metabolic parameters and detection of the expressions of insulin receptor substrate-1 (IRS-1) and IRS-2 mRNAs in the CA1 region of the hippocampus.</p><p><b>RESULTS</b>Compared with those in CD group, the rats in HFD group showed a prolonged escape latency, longer swimming distance, faster average swimming speed, and shorter stay in the platformat 12 weeks. In HFD group, the serum levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and fasting insulin were all significantly increased (P<0.05) and the level of high-density lipoprotein cholesterol decreased (P<0.01) in comparison with those in CD group at each of the time points. No significant difference was found in fast glucose levels between the two groups (P>0.05), but the expressions of IRS-1 and IRS-2 mRNAs were significantly decreased in HFD group at 12 weeks (P<0.05).</p><p><b>CONCLUSION</b>In obese rats, long-term feeding with high-fat diet leads to insulin resistance, which interferes with hippocampal expression of insulin receptor substrates and insulin metabolism to cause impairment of the cognitive function and accelerate cognitive deterioration.</p>

Protective effects of perfluorocarbon combined with ligustrazine against lung ischemia-reperfusion injury in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of perfluorocarbon and ligustrazine in protecting the lungs against ischemia-reperfusion injury in rats.</p><p><b>METHDS</b>Forty SD rats with ischemia-reperfusion lung injury were randomized equally into control, ligustrazine, perfluorocarbon, and perfluorocarbon plus ligustrazine groups and received the corresponding treatment via the tail vein 5 min before reperfusion. The lung tissues were harvested and the levels of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD) and tumor necrosis factor-α (TNF-α) were detected 3 h after reperfusion. The pathological changes and pathological scores of the lung tissues were analyzed.</p><p><b>RESULTS</b>MDA and MPO levels were significantly lower and SOD activities significantly higher in the lung tissues in the 3 treatment groups than in the control group (P<0.05). The rats in the combined treatment group showed a significantly lower MPO level and a significantly higher SOD activity than those treated with ligustrazine or perfluorocarbon alone (P<0.05). No significant difference was found in TNF-α levels in the lung tissues among the 4 groups (P>0.05). The lung tissues in the control group showed obvious edema and exudation, and the tissues in ligustrazine and perfluorocarbon groups showed no edema but with a few red blood cells and exudation; no edema was found in the combined treatment group with only a small amount of exudation. The pathological scores differed significantly among the 4 groups.</p><p><b>CONCLUSION</b>Perfluorocarbon and ligustrazine, especially in combined use, can promote endogenous oxygen free radical scavenging, decrease peripheral blood proinflammatory cytokines, and inhibit neutrophils filtration in the lungs of rats with ischemia/reperfusion lung injury.</p>

Pharmacology research on PXR as a potential target in screening bioactive components of Chinese material medica / 中国中药杂志

Pregnane X receptor (PXR) is key transcription factors which mainly regulate the expression of CYP3A genes. At the molecular level, PXR has been revealed the protection mechanism of the body against xenochemicals and a major mode of the drug-drug interactions. Besides playing an important role in drug metabolism and interactions, PXR and its target genes also play an important role in maintaining normal physiological function and homeostasis. Therefore, it is necessary to study the regulation of PXR and its related pharmacological effects of TCM and natural products, and to provide new clues for the new pharmacological pathway.

Stereological study of the placenta in parturients with different prophylactic measures for hypotension during spinal anesthesia for cesarean section / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the optimal approach to the prevention of hypotension during cesarean section for the benefits of both the parturients and the newborns.</p><p><b>METHODS</b>Forty singleton full-term pregnant women undergoing elective cesarean delivery were randomly allocated into two equal groups. For prevention of hypotension during spinal anesthesia, ephedrine or pre-anesthetic volume with Voluven was administered. The changes of blood pressure, heart rate, and Apgar scores of the newborns were monitored and recorded, and the umbilical arterial blood gas variables were compared between the two groups. The placental samples were collected and immunohistochemistry for CD34 was performed for stereological study of the placental villous capillaries.</p><p><b>RESULTS</b>The umbilical arterial PaCO(2), PaO(2) and Apgar scores showed no significant differences between the two groups (P<0.05). The heart rate, incidence of hypotension and the lactic acid value were significantly higher, and the umbilical arterial pH significantly lower in ephedrine group than in the Voluven group (P>0.05). While the length density of the villous capillaries was comparable between the two groups (P>0.05), the volume density of the villous capillaries was significantly decreased in ephedrine group (P<0.05).</p><p><b>CONCLUSION</b>Pre-anesthetic volume expansion with Voluven can maintain stable hemodynamics during spinal anesthesia and also efficiently improve the tissue perfusion, microcirculation and uteroplacental blood flow, thus increasing the oxygen supply to the fetus.</p>

Preparation and in vitro drug release performance of morphine-loaded chitosan microspheres / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare morphine-loaded chitosan microspheres by emulsion ionic cross-linking and investigate the effect of initial morphine quantity and different cross-linking degrees on drug loading, encapsulation efficiency and in vitro drug release.</p><p><b>METHODS</b>Chitosan (with a relative molecular mass of 50,000 and deacetylation degree no less than 90%) at 100 mg and morphine at 20, 30, 40, or 50 mg were dissolved by 2% acetate and dripped slowly into 15 ml soy-bean oil containing 0.75 ml Span80. After full emulsification at 35 degrees C; for 1.5 h, the mixture was dripped slowly into sodium tripolyphosphate (10 mg/ml) at the mass ratio of 5:1, 7:1, or 9:1 to allow cross-linking for 2 h. The drug loading, encapsulation efficiency and in vitro drug release of the preparations were measured.</p><p><b>RESULTS</b>The drug loading in the microsphere increased while the encapsulation efficiency reduced with the increment of the initial morphine quantity. High cross-linking degree resulted in prolonged release time of the drug loaded in the preparations.</p><p><b>CONCLUSION</b>The microspheres loaded with morphine allows sustained release of morphine.</p>

Comparison of single intubating dose and continuous infusion of rocuronium in prolonged gynecologic laparoscopic surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the cardiorespiratory factors and surgical conditions during total intravenous anesthesia for prolonged laparoscopic pelvic surgery with or without supplemental muscle relaxants.</p><p><b>METHODS</b>Forty female ASA I or II patients undergoing laparoscopic pelvic surgeries were randomized into two groups A and B, both with standardized anesthesia via a intravenous bolus injection of rocuronium (0.6 mg/kg). The patients in group B received continuous rocuronium infusion upon observation of one TOF twitch response with the T1 value maintained within 0-10% and rocuronium withdrawal at 20 to 30 min before the completion of the surgery. The patients in group A received no supplemental muscle relaxants. The cardiorespiratory parameters were measured during the operation. The respiratory system compliance (Ceff rs) was calculated as the quotient of the tidal volume (VT) and peak inspiratory pressure (PIP), and the operative conditions were graded by the operating gynecologist.</p><p><b>RESULTS</b>The cardiorespiratory parameters significant increased and Ceff rs decreased after pneumoperitoneum, but no significant differences were found between the two groups. The surgical conditions were also comparable between the two groups, but the duration of intubation and the operating time were significantly shorter in the group A.</p><p><b>CONCLUSION</b>Pneumoperitoneum severely affects the cardiorespiratory parameters during laparoscopy, which can not be lessened by neuromuscular block agents. A single intubating dose of rocuronium can suffice the requirement of prolonged gynecologic laparoscopic surgery.</p>

Epidural butorphanol analgesia in elderly patients undergoing hip replacement / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of continuous epidural analgesia (CEA) with butorphanol in elderly patients undergoing hip replacement.</p><p><b>METHODS</b>Sixty patients scheduled for selective hip replacement were randomized into group B (n=30) to receive patient-controlled epidural analgesia (PCEA) with butorphanol and group M (n=30) to receive PCEA with morphine. Their pain distribution at 5 time points, postoperative global score and the adverse effects in 48 h were observed.</p><p><b>RESULTS</b>The pain distribution at the 5 time points or the global score for postoperative PCEA in 48 h showed no statistically significant difference between the two groups (P<0.05). Analgesia with butorphanol caused less adverse effects (respiratory depression, nausea and vomiting, itching and abdominal distension) than that with morphine (P<0.05).</p><p><b>CONCLUSION</b>CEA with butorphanol is safe and effective for the treatment of postoperative pain in elderly patients and causes less adverse effects than morphine.</p>