Comparison of sagittal parameters for anterior cervical discectomy and fusion, hybrid surgery, and total disc replacement for three levels of cervical spondylosis.

PURPOSE: To analyze sagittal balance of the cervical spine after three operative methods for three consecutive levels. METHODS: A retrospective case selection and observational study was performed from December 2012 to December 2015: 20 patients underwent anterior cervical discectomy and fusion, 22 patients underwent hybrid surgery (HS), and 20 patients underwent total disc replacement (TDR). Perioperative parameters, clinical outcomes, and preoperative and postoperative sagittal parameters were recorded. RESULTS: Clinical outcomes improved. Fusion and hybrid groups were associated with more postoperative focal lordosis than the TDR group (no significant difference). The postoperative C2-7 sagittal vertical axis (SVA) was greater in the TDR group (no significant difference). In the fusion group, the postoperative C2-7 SVA was highly correlated with the preoperative C2-7 SVA and postoperative C7 slope (C7SL). Postoperative C2-7 lordosis (C2-7L) was highly correlated with the preoperative C2-7 SVA and preoperative and postoperative C7SL. In the hybrid group, postoperative C2-7L was highly correlated with preoperative C2-7L, preoperative and postoperative focal lordosis, and C7SL. In the TDR group, the postoperative C2-7 SVA was highly correlated with the preoperative C2-7 SVA and postoperative C7 slope. The postoperative C2-7 SVA was also negatively correlated with postoperative C2-7L and focal lordosis. Postoperative C2-7L was highly correlated with postoperative focal lordosis. CONCLUSIONS: For three or more levels of cervical degenerative disease, good clinical outcomes can be achieved. TDR may not be a good choice for large preoperative C2-7 SVA. HS provides good cervical range of motion and restores cervical lordosis and C2-7 SVA.

Comparison of multifidus muscle atrophy after posterior lumbar interbody fusion with conventional and cortical bone trajectory.

OBJECTIVE: To determine if minimally invasive posterior interbody fusion with cortical bone trajectory (CBT) is associated with reduced paraspinal muscle damage compared to conventional open posterior lumbar interbody fusion (PLIF). METHODS: Sixteen consecutive patients who underwent CBT were grouped into matched pairs with 16 patients who underwent conventional PLIF between May 2013 and January 2014, in terms of age, sex, body mass index, and spinal levels. Perioperative data and clinical data, including the Japanese Orthopedics Association (JOA) score, visual analogue scale (VAS) score, Oswestry Disability Index (ODI),before and after surgery were evaluated. Magnetic resonance imaging was performed preoperatively and 6 months postoperatively. The fat infiltration ratio was calculated. RESULTS: Thirty-two patients with an 18-month follow-up period were evaluated. Clinical improvement, indicated by the VAS score for back and leg pain, ODI, and JOA score, was significant in both groups. However, there were no significant differences in operative time, blood loss, hospital stay duration, and recovery rate between the groups. The fat infiltration ratio was lower in the CBT group (p<0.05) than in the conventional PLIF group. CONCLUSIONS: CBT is comparable with conventional PLIF with respect to short-term clinical outcomes but induced less multifidus muscle damage.

17ß-Estradiol attenuates secondary injury through activation of Akt signaling via estrogen receptor alpha in rat brain following subarachnoid hemorrhage.

BACKGROUND: Apoptosis is implicated in vasospasm and the long-term sequelae of subarachnoid hemorrhage (SAH). This study tested the hypothesis that attenuation of SAH-induced apoptosis after 17ß-estradiol (E2) treatment is associated with an increase in phosphorylation of Akt via estrogen receptor-α (ER-α) in rats. MATERIALS AND METHODS: We examined the expression of phospho-Akt, ERα and ERß, and apoptosis in cerebral cortex, hippocampus, and dentate gyrus in a two-hemorrhage SAH model in rats. We subcutaneously implanted other rats with a silicone rubber tube containing E2; they received daily injections of nonselective estrogen receptor antagonist (ICI 182,780), selective ERα-selective antagonist (methyl-piperidino-pyrazole), or ERß-selective antagonist (R,R-tetrahydrochrysene) after the first hemorrhage. RESULTS: At 7 d after the first SAH, protein levels of phospho-Akt and ERα were significantly decreased and caspase-3 was significantly increased in the dentate gyrus. The cell death assay revealed that DNA fragmentation was significantly increased in the dentate gyrus. Those actions were reversed by E2 and blocked by ICI 182,780 and methyl-piperidino-pyrazole, but not R,R-tetrahydrochrysene. However, there were no significant changes in the expression of the protein levels of phospho-Akt, ERα, ERß, and caspase-3, and DNA fragmentation after SAH. CONCLUSIONS: The present study shows that a beneficial effect of E2 in attenuating SAH-induced apoptosis is associated with activation of the expression of phospho-Akt and ERα, and alteration in caspase-3 protein expression via an ERα-dependent mechanism in the dentate gyrus. These data support further the investigation of E2 in the treatment of SAH in humans.

Attenuating heatstroke-induced acute lung inflammation, edema, and injury in rats by exercise preconditioning.

BACKGROUND: This study aimed to ascertain whether heat-induced acute lung edema, inflammation, and ischemic damage can be affected by heat shock protein 70 (HSP-70)-mediated exercise preconditioning (EP) in rats. METHODS: Wistar rats were assigned to one of the following four groups: the non-EP + nonheated group, the non-EP + heated group, the EP + heated group, and the EP + HSP-70 antibodies + heated group. EP groups of animals were subjected to a protocol of running on a treadmill for 30 minutes at 20 m/min, 30 minutes at 30 m/min, and 60 minutes at 30 m/min after 1, 2, and 3 weeks of training, respectively. Heated group of animals, under general anesthesia, were put in a folded heating pad of 43°C for 68 minutes. Then, the heated animals were allowed to recover at room temperature. HSP-70 antibodies were injected intravenously 24 hours before heat exposure. RESULTS: As compared with the non heated + non-EP rats, the heated + non-EP rats had significantly higher scores of alveolar edema, neutrophil infiltration, and hemorrhage, acute pleurisy, and increased bronchoalveolar fluid levels of proinflammatory cytokines and ischemic and oxidative damage markers. EP, in addition to inducing overexpression of HSP-70 in lung tissues, significantly attenuated heat-induced acute pulmonary edema, inflammation, and ischemic and oxidative damage in the lungs. HSP-70 antibodies, in addition to reducing HSP-70 expression in the lungs, significantly attenuated the beneficial effects of EP in reducing acute lung inflammation and injury. CONCLUSION: EP may attenuate the occurrence of pulmonary edema, inflammation, as well as ischemic and oxidative damage caused by heatstroke by up-regulating HSP-70 in the lungs.

Tetramethylpyrazine decreases hypothalamic glutamate, hydroxyl radicals and prostaglandin-E2 and has antipyretic effects.

OBJECTIVE: We studied the effects of tetramethylpyrazine (TMP) on the fever, increased plasma levels of tumor necrosis factor-α (TNF-α) and increased hypothalamic levels of glutamate, hydroxyl radicals and prostaglandin-E2 (PGE2) induced by lipopolysaccharide (LPS). MATERIALS AND METHODS: The microdialysis probes were stereotaxically and chronically implanted into the hypothalamus of rabbit brain for determining extracellular levels of glutamate, hydroxyl radials, and PGE2. In addition, both the body core temperature and plasma levels of TNF-α were measured. RESULTS: All the body core temperature, plasma levels of TNF-α, and hypothalamic levels of glutamate, hydroxyl radicals, and PGE2 were up-graded by an intravenous dose of LPS (2 µg/kg). Pretreatment with intravenous TMP (10-40 mg/kg) or intracerebroventricular TMP (130 µg in 20 µl per animal) 1 h before LPS administration significantly attenuated the LPS-induced fever as well as the increased hypothalamic levels of glutamate, hydroxyl radicals, and PGE2. LPS-induced fever could also be attenuated by intravenous or intracerebroventricular TMP 1 h after LPS injection. CONCLUSION: TMP preconditioning may cause its antipyretic action by reducing plasma levels of TNF-α as well as hypothalamic levels of glutamate, hydroxyl radicals, and PGE2 in rabbits.

Hydrogen peroxide decreases the survival rate of HeLa cells with stable knockdown of survival motor neuron protein.

The mutations of survival motor neuron (SMN) gene result in spinal muscular atrophy (SMA), a common neurodegenerative disease. Some of the motor neurons undergoing cell death is the predominant characteristic in SMA pathology. However, the viability and sensitivity to stresses of other cell types also need to be determined. In this article, we established HeLa stable cell line with inducible SMN knockdown to study its viability and sensitivity to oxidative stress. SMN knockdown in the HeLa stable cell line was induced by doxycycline. The proliferative and survival rates of SMN knockdown cells with or without hydrogen peroxide (H(2)O(2)) treatment were determined. Our results showed that the proliferative rate of SMN knockdown cells decreased only slightly compared with that of the cells without doxycycline treatment. In contrast, after H(2)O(2) reached certain concentrations, the survival rate of SMN knockdown cells decreased significantly. Our data indicate that SMN knockdown alone is not critical to cell viability. However, when SMN knockdown cells are under stress, such as oxidative stress, their survival rate may significantly decrease. Our results will be helpful to prevent the detrimental effect caused by the cell death of non-motor neurons under stress in SMA patients. In addition, the cell model we established can be used to study the mechanism and screen drugs to prevent the detrimental effects in cases of SMA disease.

Stromal cell-derived factor-1/CXCR4 promotes IL-6 production in human synovial fibroblasts.

The production of chemokine stromal cell-derived factor (SDF)-1 is significantly higher in synovial fluid of patients with osteoarthritis (OA). IL-6 is a multifunctional cytokine that plays a central role in both OA and rheumatoid arthritis. However, the effects of SDF-1α on human synovial fibroblasts are largely unknown. In this study, we investigated the intracellular signaling pathway involved in SDF-1α-induced IL-6 production in human synovial fibroblast cells. SDF-1α caused concentration- and time-dependent increases in IL-6 production. SDF-1α also increased the mRNA and surface expression of CXCR4 receptor in human synovial fibroblasts. CXCR4-neutralizing antibody, CXCR4-specific inhibitor (AMD3100), or small interfering RNA against CXCR4 inhibited the SDF-1α-induced increase of IL-6 expression. The transcriptional regulation of IL-6 by SDF-1α was mediated by phosphorylation of phosphatidylinositol 3-kinase (PI3K)/Akt and activation of the activator protein (AP)-1 component of c-Jun. The binding of c-Jun to the AP-1 element on the IL-6 promoter and the increase in AP-1 luciferase activity was enhanced by SDF-1α. Co-transfection with CXCR4, PI3K, Akt, and c-Jun mutants or siRNA inhibited the potentiating action of SDF-1α on AP-1 promoter activity. Taken together, our results suggest that SDF-1α-increased IL-6 production in human synovial fibroblasts via the CXCR4 receptor, PI3K, Akt, c-Jun, and AP-1 signaling pathways.

Central interleukin-10 attenuated lipopolysaccharide-induced changes in core temperature and hypothalamic glutamate, hydroxyl radicals and prostaglandin-E(2).

It has been documented that intravenous lipopolysaccharide (LPS) in rabbits causes fever accompanied by increased levels of extracellular glutamate, hydroxyl radicals, and prostaglandin E(2) (PGE(2)) in the hypothalamus and circulating tumor necrosis factor-alpha (TNF-α). This investigation was to determine whether central interleukin-10 (IL-10) exerted its antipyresis by reducing changes in circulating TNF-α and extracellular glutamate, hydroxyl radicals and PGE(2) in the hypothalamus. The microdialysis probes were stereotaxically and chronically implanted into the preoptic anterior hypothalamus of rabbit brain for determinating extracellular glutamate, hydroxyl radicals, and PGE(2) in situ. It was found that systemically injected LPS (2µg/kg, intravenously) increased the levels of core temperature, and extracellular glutamate, hydroxyl radicals, and PGE(2) in the hypothalamus accompanied by increased plasma levels of TNF-α. Pretreatment with IL-10 (10-100ng, intracerebroventricularly) 1h before intravenous LPS significantly reduced the LPS-induced changes in extracellular glutamate, hydroxyl radicals, and PGE(2) in the hypothalamus and fever, but not the increased levels of TNF-α in rabbits. These findings suggested that directly injected IL-10 into the lateral cerebral ventricle 1h before intravenous LPS exerted its antipyresis by inhibiting the changes in extracellular glutamate, hydroxyl radicals and PGE(2) in the hypothalamus during LPS fever in rabbits.

Body cooling ameliorating spinal cord injury may be neurogenesis-, anti-inflammation- and angiogenesis-associated in rats.

BACKGROUND: Body cooling (BC) or mild hypothermia therapy (about 33°C) is reportedly effective for spinal cord injury (SCI). However, the mechanisms underlying the beneficial effects of BC remain unclear, so does BC ameliorating SCI via promoting neurogenesis, anti-inflammation, and angiogenesis. METHODS: The standard rat compression SCI model was tested hypothetically in two groups: one receiving BC (33°C) and the other, normothermia (37°C). Afterward, the effects of BC therapy on the hind limb locomotion, spinal cord infarction and apoptosis, angiogenesis, neurogenesis, and inflammation in these two groups of SCI were assessed. The other group of sham SCI was used as controls. RESULTS: Apoptosis (evidenced by higher numbers of terminal deoxynucleotidyl- transferase-mediated and duDP-biotin nick end-labeling-positive cells), infarct, activated inflammation (evidenced by higher levels of tumor necrosis factor-α, interleukin-1ß, and myeloperoxidase), and hind limb locomotor dysfunction were inspected in the untreated (37°C) SCI rats 4 days after SCI. When compared with those of untreated SCI rats, SCI rats receiving BC (33°C) displayed lower levels of apoptosis, infarct volume, activated inflammation, and hind limb locomotor dysfunction. In addition, that BC promoted both angiogenesis (evidenced by increased numbers of both vascular endothelial growth factors and bromodeoxyuridine-positive endothelial cells) and neurogenesis (evidenced by increased numbers of both glial cell line-derived neurotrophic growth factors and bromodeoxyuridine-neuronal-specific nuclear protein double positive cells) in the injured spinal cord was evaluated 4 days after SCI. CONCLUSION: BC (33°C) improved SCI outcomes by promoting angiogenesis, neurogenesis, and anti-inflammation in a rat SCI model.

Inhibition of the mammalian target of rapamycin promotes cyclic AMP-induced differentiation of NG108-15 cells.

To clarify the involvement of autophagy in neuronal differentiation, the effect of rapamycin, an mTOR complex inhibitor, on the dibutyryl cAMP (dbcAMP)-induced differentiation of NG108-15 cells was examined. Treatment of NG108-15 cells with 1 mM dbcAMP resulted in induction of differentiation, including neurite outgrowth and varicosity formation, enhanced voltage-sensitive Ca2+ channel activity and expression of microtubule-associated protein 2, and these effects involved phosphorylation of cAMP-response element binding protein (CREB) and extracellular signal regulated kinase (ERK). Simultaneous application of dbcAMP and rapamycin synergistically increased and accelerated differentiation. mTOR or raptor silencing with siRNA had a similar effect to rapamycin. Rapamycin and silencing of mTOR or raptor evoked autophagy, while blockade of autophagy by addition of 3-methyladenine or beclin 1 or Atg5 silencing prevented the potentiation of differentiation. Silencing of rictor also evokes autophagy, at a level 55% of that induced by raptor silencing and enhancement of differentiation is proportional. Rapamycin also caused increased ATP generation and cell cycle arrest in G0/G1 phase, but had no effect on CREB and ERK phosphorylation. dbcAMP also induced ATP generation, but not autophagy or cell cycle arrest. These results suggest that the increased autophagy, ATP generation and cell cycle arrest caused by mTOR inhibition promotes the dbcAMP-induced differentiation of NG108-15 cells.

Phenothiazine-type antipsychotics elicit cutaneous analgesia in rats.

BACKGROUND: Local anesthetics exert their anesthetic and analgesic effects by blocking the sodium channels in the nervous system. Phenothiazine-type antipsychotics also block sodium channels, but the local anesthetic characteristics of these drugs have not been evaluated. The aim of this study was to evaluate the cutaneous analgesic effect of phenothiazine-type antipsychotics. METHODS: Using a subcutaneous injection model in rats, we tested the cutaneous analgesic effects of six phenothiazine-type antipsychotics (mesoridazine, promazine, chlorpromazine, fluphenazine, perphenazine and triflupromazine) at a dose of 0.6 mumol, and compared them with those of bupivacaine and lidocaine. A saline injection was used as the control. RESULTS: All six phenothiazine-type antipsychotics elicited cutaneous analgesia. At the dose of 0.6 mumol, the potencies of mesoridazine and promazine were similar to that of bupivacaine; the other four drugs were less potent (p<0.001 for each comparison). Mesoridazine had a longer duration of action than bupivacaine (p<0.001). In terms of ED(50) values, mesoridazine was more potent and longer-acting than bupivacaine and lidocaine (p<0.01 for each comparison). CONCLUSION: Of the antipsychotic drugs tested, mesoridazine is potentially the best candidate for development into a potent, long-acting local anesthetic. However, toxicity studies are needed before these agents can be used clinically as analgesics.

Attenuation of cerebral vasospasm and secondary injury by 17beta-estradiol following experimental subarachnoid hemorrhage.

OBJECT: Cerebral vasospasm remains a major complication in patients who have suffered a subarachnoid hemorrhage (SAH). Previous studies have shown that 17beta-estradiol (E2) attenuates experimental SAH-induced cerebral vasospasm. Moreover, E2 has been shown to reduce neuronal apoptosis and secondary injury following cerebral ischemia. Adenosine A1 receptor (AR-A1) expression is increased following ischemia and may represent an endogenous neuroprotective effect. This study was designed to evaluate the efficacy of E2 in preventing cerebral vasospasm and reducing secondary injury, as evidenced by DNA fragmentation and AR-A1 expression, following SAH. METHODS: A double-hemorrhage model of SAH in rats was used, and the degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery 7 days after the first SAH. A cell death assay was used to detect apoptosis. Changes in the protein expression of AR-A1 in the cerebral cortex, hippocampus, and dentate gyrus were compared with levels in normal controls and E2-treated groups (subcutaneous E2, 0.3 mg/ml). RESULTS: The administration of E2 prevented vasospasm (p < 0.05). Seven days after the first SAH, DNA fragmentation and protein levels of AR-A1 were significantly increased in the dentate gyrus. The E2 treatment decreased DNA fragmentation and prevented the increase in AR-A1 expression in the dentate gyrus. There were no significant changes in DNA fragmentation and the expression of AR-A1 after SAH in the cerebral cortex and hippocampus in the animals in the control and E2-treated groups. CONCLUSIONS: The E2 was effective in attenuating SAH-induced cerebral vasospasm, decreasing apoptosis in the dentate gyrus, and reducing the expression of AR-A1 in the dentate gyrus after SAH. Interestingly, E2 appears to effectively prevent cerebral vasospasm subsequent to SAH as well as attenuate secondary injury by reducing both apoptosis and a compensatory increase in AR-A1 expression in the dentate gyrus.

Exogenous administration of glial cell line-derived neurotrophic factor improves recovery after spinal cord injury.

The aim of present study was to examine whether systemically delivered glial cell-derived neurotrophic factor (GDNF) was beneficial in reversing the spinal cord injury (SCI) in a spinal cord compression model. Rats were divided into three major groups: (1) sham operation (laminectomy only); (2) laminectomy+SCI+normal saline (1 ml/kg, i.v.); (3) laminectomy+SCI+GDNF (50 ng/kg, i.v.). Spinal cord injury was induced by compressing the spinal cord for 1 min with an aneurysm clip calibrated to a closing pressure of 55 g. GDNF or saline was administered immediately after SCI via the tail vein. Behavioral tests of motor function measured by maximal angle an animal could hold to the inclined plane were conducted at days 1-7 after SCI. The triphenyltetrazolium chloride staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay were also conducted after SCI to evaluate spinal cord infarction and apoptosis, respectively. Both GDNF and vascular endothelial growth factor (VEGF) in the injured spinal cord were assayed by immunofluorescence. It was found that systemically delivered GDNF, but not vehicle solution, significantly attenuated the SCI-induced hind limb dysfunction and spinal cord infarction and apoptosis. Both GDNF and VEGF could be detected in the injury spinal cord after GDNF, but not vehicle solution, therapy. The results indicate that GDNF treatment may be beneficial in reversing hind limb dysfunction by reducing spinal cord infarction and apoptosis in a spinal cord compression model.

The incidence and characterisation of hospitalised acute spinal trauma in Taiwan--a population-based study.

AIMS: The purpose of this study was to perform a cross-sectional population-based study of hospitalised cases due to acute spinal trauma in Taiwan, based on information from the nationwide National Health Insurance (NHI) database. METHODS: To calculate the annual incidence of hospitalised acute spinal trauma, evaluate the distribution of neurological injury and its surgical intervention, and analyse the use of medical resources and related factors in Taiwan, the entire inpatient datasets were selected between 2000 and 2003 for use in the present study. RESULTS: There were 13,371, 13,800, 13,728 and 13,585 cases identified in 2000, 2001, 2002 and 2003, respectively, the average incidence of hospitalised acute spinal trauma in Taiwan was 61.61/100,000, and it was similar in both genders (rate ratio of male to female: 0.99). There was a significant trend of increased incidence with increasing age in both genders, particularly after the age of 60. The decreasing incidence rate ratios of neurological deficit to neurological intactness are 0.75, 0.58, 0.45, 0.26 and 0.16 in the age strata of 0-19, 20-39, 40-59, 60-79 and 80 or more years, respectively. In general, the operation rate is only 17.3% of all acute spinal injury cases, but it would be up to a significant 29.5% if the patients had spinal fractures with neurological insufficiency. There is an obvious decreasing trend of operation rate in spinal bony trauma with age, but a reverse trend is noted in the group with spinal nerve injury without spinal fracture. Finally, the enrolled subjects of acute spinal injuries spent $NT 43336.3+/-80270.2 (equal to US$ 1313+/-2432) and stayed for 8.5+/-8.9 days in hospital. The above two variables of hospitalised medical utilisation are significantly different when considering gender, neurological status, and surgical intervention or not. Noticeably, if operative treatment for acute spinal injury is necessary, the LOS would increase by two times and the medical cost by six times. CONCLUSION: In Taiwan, the annual incidence of hospitalised acute spinal injuries was higher but the direct cost was much lower. The characterisation of gender ratio, neurological condition, and surgical performance had been significantly effected by age.

Human umbilical cord blood-derived CD34+ cells may attenuate spinal cord injury by stimulating vascular endothelial and neurotrophic factors.

Human umbilical cord blood-derived CD34(+) cells were used to elucidate the mechanisms underlying the beneficial effects exerted by cord blood cells in spinal cord injury (SCI). Rats were divided into four groups: (1) sham operation (laminectomy only); (2) laminectomy + SCI + CD34(-) cells (5 x 10(5) human cord blood lymphocytes and monocytes that contained <0.2% CD34(+) cells); (3) laminectomy + SCI + CD34(+) cells (5 x 10(5) human cord blood lymphocytes and monocytes that contained approximately 95% CD34(+) cells); and (4) laminectomy + SCI + saline (0.3 mL). Spinal cord injury was induced by compressing the spinal cord for 1 min with an aneurysm clip calibrated to a closing pressure of 55 g. CD34 cells or saline was administered immediately after SCI via the tail vein. Behavioral tests of motor function measured by maximal angle an animal could hold to the inclined plane were conducted at days 1 to 7 after SCI. The triphenyltetrazolium chloride staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay were also conducted after SCI to evaluate spinal cord infarction and apoptosis, respectively. To elucidate whether glial cell line-derived neurotrophic factor (GDNF) or vascular endothelial growth factor (VEGF) can be secreted in spinal cord-injured area by the i.v. transplanted CD34(+) cells, analysis of spinal cord homogenate supernatants by specific enzyme-linked immunosorbent assay for GDNF or immunofluorescence for VEGF was conducted. It was found that systemic administration of CD34(+), but not CD34(-), cells significantly attenuated the SCI-induced hind limb dysfunction and spinal cord infarction and apoptosis. Both GDNF and VEGF could be detected in the injured spinal cord after transplantation of CD34(+), but not CD34(-), cells. The results indicate that CD34(+) cell therapy may be beneficial in reversing the SCI-induced spinal cord infarction and apoptosis and hindlimb dysfunction by stimulating the production of both VEGF and GDNF in a spinal cord compression model.

Prevention and suppression of pyrogenic fever in rabbits by hyperbaric oxygen.

Current investigation was to determine whether hyperbaric oxygen had an effect on the febrile responses to systemic administration of lipopolysaccharide. An intravenous dose of lipopolysaccharide (2 microg/kg) caused an increase in core temperature accompanied by both plasma tumor necrosis factor-alpha and hypothalamic prostaglandin E(2) overproduction in rabbits. Administering hyperbaric oxygen (100% at 253 kPa) but not normobaric oxygen (100% at 101 kPa), once a day for consecutive 7 days prior to or 1 h after injecting lipopolysaccharide significantly reduced the lipopolysaccharide-induced elevation of both core temperature and circulating tumor necrosis factor-alpha. As compared to those of the simultaneous administration of normobaric air and lipopolysaccharide, administering hyperbaric oxygen or air plus lipopolysaccharide simultaneously had lesser febrile effects in terms of core temperature elevation, tumor necrosis factor-alpha overproduction and hypothalamic prostaglandin E(2) accumulation. However, the febrile responses produced by simultaneous application of normobaric oxygen plus lipopolysaccharide were not significantly different from those of normobaric air plus lipopolysaccharide. The results indicate that hyperbaric oxygen, and to some extent hyperbaric air, may cause prevention and suppression of pyrogenic fever by reducing overproduction of both circulating tumor necrosis factor-alpha and hypothalamic prostaglandin E(2).

The spinal anaesthetic effect of dextromethorphan, dextrorphan, and 3-methoxymorphinan.

Dextromethorphan, an antitussive, has a complex pharmacologic profile and has not been well studied. Our aim was to evaluate whether dextromethorphan and its metabolites, dextrorphan and 3-methoxymorphinan, have a spinal anaesthetic effect. Using a method of spinal blockade in rats, we evaluated the potencies and durations of the effects of dextromethorphan and its metabolites on spinal blockades of motor function and nociception. Bupivacaine was the active control. We found that dextromethorphan and its metabolites produced a dose-related spinal blockade of motor function and nociception. On an ED(50) basis, the ranks of potencies were bupivacaine>dextrorphan>3-methoxymorphinan>dextromethorphan (p<0.05 for the differences). On an equipotent basis, dextrorphan and bupivacaine produced similarly longer nociceptive blockades than did dextromethorphan and 3-methoxymorphinan (p<0.05 for the differences). Co-administration of dextromethorphan or its metabolites with bupivacaine produced an additive effect. In conclusion, intrathecal injections of dextromethorphan or its metabolites, dextrorphan and 3-methoxymorphinan, produced dose-related spinal blockades of motor function and nociception. The suitability of these drugs as clinical spinal anaesthetics is worth further evaluation.

Lipopolysaccharide- and glutamate-induced hypothalamic hydroxyl radical elevation and fever can be suppressed by N-methyl-D-aspartate-receptor antagonists.

The purpose of the current study was to explore the effects of N-methyl-D-aspartate (NMDA)-receptor antagonists (MK-801 and LY235959) administered intracerebroventricularly on the changes of both core temperature and hypothalamic levels of 2,3-dihydroxybenzoic acid (2,3-DHBA) induced by intracerebroventricular injection of glutamate (100 - 400 microg at 10 microl/rabbit) or intravenous administration of lipopolysaccharide (LPS) (2 microg/kg) in rabbits. The measurements of 2,3-DHBA were used as an index of the intrahypothalamic levels of hydroxyl radicals. The rise in both the core temperature and hypothalamic 2,3-DHBA could be induced by intracerebroventricular injection of glutamate or intravenous administration of LPS. The glutamate- or LPS-induced fever and increased hypothalamic levels of 2,3-DHBA were significantly antagonized by pretreatment with injection of MK-801 or LY235959 1 h before glutamate or LPS injection. The increased levels of prostaglandin E2 in the hypothalamus induced by glutamate or LPS could be suppressed by MK-801 or LY235959. The data demonstrate that prior antagonism of NMDA receptors in the brain, in addition to reducing prostaglandin E2 production in the hypothalamus, suppresses both the glutamate- and LPS-induced fever and increased hypothalamic hydroxyl radicals.

Effect of anandamide on cytosolic Ca(2+) levels and proliferation in canine renal tubular cells.

The effect of the endogenous cannabinoid anandamide on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and proliferation is largely unknown. This study examined whether anandamide altered Ca(2+) levels and caused Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Anandamide at concentrations above 5 muM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 78% by removing extracellular Ca(2+). The anandamide-induced Ca(2+) influx was insensitive to L-type Ca(2+) channel blockers and the cannabinoid receptor antagonist AM 251, but was inhibited differently by aristolochic acid, WIN 55,212-2 (a cannabinoid receptor agonist), phorbol ester, GF 109203X and forskolin. After pretreatment with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), anandamide-induced Ca(2+) release was inhibited. Inhibition of phospholipase C with U73122 did not change anandamide-induced Ca(2+) release. At concentrations of 100 muM and 200 muM, anandamide killed 50% and 95% cells, respectively. The cytotoxic effect of 100 muM anandamide was completely reversed by pre-chelating cytosolic Ca(2+) with BAPTA. Collectively, in MDCK cells, anandamide induced [Ca(2+)](i) rises by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, anandamide can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.

Dual effect of flurbiprofen on cell proliferation and agonist-induced Ca(2+) movement in human osteosarcoma cells.

In human MG63 osteosarcoma cells, the effect of flurbiprofen on intracellular Ca(2+) concentrations ([Ca(2+)](i)) and proliferation was explored. The proliferation was enhanced by 20-120 microM flurbiprofen, and was decreased by 140-200 microM flurbiprofen. The effect of flurbiprofen on the increases in cytosolic free Ca(2+) levels ([Ca(2+)](i)) induced by ATP, bradykinin, histamine and thapsigargin (an inhibitor of the endoplasmic reticulum Ca(2+) ATPase), was examined. In cell preincubated with 20 or 80 microM flurbiprofen, the [Ca(2+)](i) increases induced by all agonists were attenuated. In the presence of 20 microM flurbiprofen, the decreased [Ca(2+)](i) responses with the agonists were attributed to a defective Ca(2+) influx because this decrease was unobserved in agonists-induced [Ca(2+)](i) increases in the absence of extracellular Ca(2+). In the presence of 80 microM flurbiprofen, both the Ca(2+) influx component and the Ca(2+) releasing (from organelles) component were defective. These results suggest that flurbiprofen could alter proliferation and inhibit [Ca(2+)](i) increases.