Epidural bupivacaine suppresses local glucose utilization in the spinal cord and brain of rats

Using the 2-[14C]deoxyglucose method, the effects of analgesic doses of epidural bupivacaine (300 micrograms) on local spinal cord glucose utilization (SP-LGU) of the cervical, thoracic, and lumbar regions and local cerebral glucose utilization (BR-LGU) in 38 brain structures were examined in conscious rats. In addition, the effects of intramuscular bupivacaine (300 micrograms) and the spinal cord transection (T2) were examined to determine whether the induced metabolic changes, if any, are related to the drug's systemic effect and/or deafferentation. Lumbar epidural bupivacaine sufficient to produce analgesia decreased SP-LGU in the thoracic (18-28%) and lumbar (21-29%) spinal cord but not in the cervical cord. Epidural bupivacaine decreased BR-LGU (15-26%) in 35 of 38 structures examined. With intramuscular bupivacaine, SP-LGU remained unchanged in almost all regions, while BR-LGU was significantly decreased (11-23%) in 23 structures. Plasma concentrations of bupivacaine in the epidural and intramuscular groups were comparable. With spinal cord transection alone, SP-LGU significantly decreased with varying degrees depending on the structure examined, but BR-LGU did not decrease in 36 of 38 structures examined. These results indicate that analgesic doses of epidural bupivacaine decrease SP-LGU, probably reflecting decreased neuronal activity of the spinal cord, and that reduced BR-LGU by epidural bupivacaine is most likely due to the drug's systemic effect rather than deafferentation.     

Stability of messenger RNA in postmortem human brains and construction of human brain cDNA libraries

We studied stabilities of poly(A)⁺-RNA in postmortem mouse and human brains for up to 12 hours. The yields of total RNA were not changed significantly during postmortem periods either in mouse brains or human brains. Cell-specific cDNA probes were used to evaluate postmortem stability of poly(A)⁺-RNA in each cell type in the central nervous system. We used neuronspecific enolase (NSE), S-100β (S-100), and myelin-associated glycoprotein (MAG) for molecular markers of neuron, astrocyte, and oligodendrocyte, respectively. There was no detectable degradation of mRNAs coding for NSE, S-100, and MAG during the postmortem periods on Northern blot hybridization analyses. These results indicate that intact mRNAs expressed in neuron, astrocyte, or oligodendrocyte can be isolated from postmortem brains for up to 12 hours after death. Using poly(A)⁺-RNA thus isolated from two postmortem human brains, we constructed directional cDNA libraries and demonstrated the presence of full-length cDNAs for NSE, S-100, and MAG on Southern blot hybridization analysis. The present data should encourage studies on altered gene expressions in human brain in various neurologic diseases.     

Effects of impaired functional domains of osteopontin on renal crystal formation: Analyses of OPN transgenic and OPN knockout mice

Osteopontin (OPN) has been described as playing a nonredundant role in renal crystal formation. Here we investigated the effects of impaired domains of OPN, namely, the Arg‐Gly‐Asp (RGD) sequence and two calcium‐binding sites on crystal formation. We used wild‐type mice (WT group), OPN knockout mice (KO group), and OPN knockout mice carrying either a transgene in which the RGD sequence had been modified to Arg‐Gly‐Glu (RGE group) or whose two calcium‐binding sites had been deleted (CaX group). Following intraperitoneal injection of glyoxylate for 9 days, the changes occurring in three parameters of crystal formation—localization, number, and microstructure—were analyzed. In the WT group, crystal deposits increased gradually at the renal corticomedullary junction in an orderly fashion, whereas those in the KO group were observed sporadically in the renal cortex. In both the CaX and RGE groups, deposits were localized near the corticomedullary junction. Crystal deposition was greatest in the WT group and least in the KO group. The number of deposits in the RGE group was nearly equal to that in the KO group. Microscopic observations revealed that the crystal nuclei in the CaX group were stratified and occurred in a disordered pattern; this pattern was dissimilar to that in the WT group, in which a rosette petal–like radial pattern was observed. In the RGE group, the nuclei exhibited a radial pattern similar to that in the WT group. The results indicated the possibility that each domain contributes to the mechanism by which OPN stimulates crystal formation. © 2010 American Society for Bone and Mineral Research.     

Stability of volar locking plate systems for AO type C3 fractures of the distal radius: biomechanical study in a cadaveric model

Background  

The purpose of the present study was to compare the relative stability of five volar locking plates (all of which are available for the treatment of intraarticular fractures of the distal radius) under loading conditions simulating the physiological forces that occur during early active mobilization.     

Drug resistance of Pseudomonas aeruginosa in four community hospitals: influence of antimicrobial use density

We investigated the relation between hospital antimirobial use density (AUD) and minimum inhibitory concentrations (MIC) for Pseudomonas aeruginosa in four community hospitals. Subjects were a total of 476 strains isolated from urine, sputum, and pus during a total of seven years since 2002, for which 50- and 90-percentile MICs were analyzed. Hospitals A, B, and C moved in 2000, 2005, and 2009, respectively, but MIC50 and MIC90 were stable. MIC values showed significance in five drugs, in which Hospital B showed maximal values in five and Hospital D showed minimal values in four drugs. AUD values were different in nine drugs, Hospital B showing the highest data in meropenem, flomoxef, and sulbactam/cefoperazone while Hospital D having the lowest data in meropenem, ceftazidime, cefotaxime, and sulbactam/cefoperazone. Thus MIC for P aeruginosa may show resistance in the presence of high AUD with wide antimicrobial spectrum.