Lamotrigine prevents MK801-induced alterations in early growth response factor-1 mRNA levels and immunoreactivity in the rat brain.

MK801 (dizocilpine) induces selective neurotoxic effects in the retrosplenial cortex, ranging from neuronal vacuolization to irreversible neurodegeneration depending on the dose administered. Although lamotrigine prevents MK801-induced neuronal vacuolization in the retrosplenial cortex 4 h after injection, it is not clear whether lamotrigine attenuates the subsequent neurodegeneration that occurs 3-4 days later. Because early growth response factor-1 (egr-1) plays a key role in neurodegeneration and its expression is induced in the retrosplenial cortex following MK801 treatment, it is possible that lamotrigine may attenuate MK801-induced neurodegeneration via inhibition of egr-1 expression in the retrosplenial cortex. To address this issue, we treated rats with lamotrigine (10 or 20 mg/kg) followed by MK801 (2 mg/kg) and measured changes in the levels of egr-1 mRNA and immunoreactivity in the retrosplenial cortex and other brain regions 3 h later. We also evaluated the effects of these treatments on neurodegeneration 4 days following treatment using Fluoro-Jade B staining. MK801 treatment increased egr-1 mRNA and immunoreactivity in the restrosplenial, cingulate, entorhinal and piriform cortices, but decreased levels in hippocampal subfields. These MK801-induced changes in egr-1 expression were significantly inhibited by lamotrigine pretreatment. In addition, MK801-induced neurodegeneration in the retrosplenial cortex was partially blocked by lamotrigine pretreatment in a dose dependent manner. These results demonstrate that lamotrigine pretreatment prevents the MK801-induced upregulation of egr-1 expression in a region-selective manner, and suggest that this effect may contribute, in part, to the attenuation of MK801-induced neurodegeneration in the retrosplenial cortex.

Characterization of human insulin microcrystals and their absorption enhancement by protease inhibitors in rat lungs.

Pulmonary route appears to be an attractive alternative as a non-invasive systemic delivery for peptide and protein drugs. An appropriate formulation, however, is important for increasing their bioavailability in lung. In this study, the human insulin microcrystals were produced. The particle size analysis and scanning electron microscopy (SEM) showed that the microcrystals were uniform and had a monodispersed size distribution (mean diameter = 0.95 microm) for pulmonary delivery. The physicochemical properties of the microcrystals developed were similar to those of the commercial crystalline powder in powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses. The percentage of high molecular weight proteins (%HMWP), the percentage of other insulin related compounds (%OIRC) and the percentage of A-21 desamido insulin (%D) of the microcrystals were very low. In addition, the cytotoxicity of microcrystals developed and protease inhibitors (aprotinin, bacitracin and soybean-trypsin inhibitor) was investigated, and the enhancement of insulin absorption in the presence of these protease inhibitors at various concentrations was studied. The cell viability of A549 was over 80% at various concentrations of aprotinin and soybean-trypsin inhibitor, except for bacitracin (below 60%). The percent of decrease in blood glucose (D%) was 42.68+/-1.62% after intratracheal instillation of insulin microcrystals (5 U/kg). An enhancement of hypoglycemic effect with protease inhibitors was also found. Soybean-trypsin inhibitor (48.86+/-3.24% at 10 mg/ml; 55.78+/-0.71% at 5 mg/ml; 51.49+/-5.27% at 1 mg/ml) and aprotinin (52.57+/-8.78% at 10 mg/ml; 51.97+/-1.98% at 5 mg/ml; 56.90+/-3.42% at 1 mg/ml) were effective for absorption enhancement. These findings suggest that the use of insulin microcrystals and protease inhibitors would be useful to improve the hypoglycemic effect in pulmonary route.

Effects of repeated tianeptine treatment on CRF mRNA expression in non-stressed and chronic mild stress-exposed rats.

Accumulating evidence suggests that dysregulation of corticotropin-releasing factor (CRF) may play a role in depression and that this dysregulation may be corrected by antidepressant drug treatment. Here, we examined whether chronic mild stress (CMS) alters CRF mRNA levels in stress-related brain areas including the bed nucleus of the stria terminalis (BNST) and the central nucleus of amygdala (CeA), and whether repeated tianeptine treatment can attenuate CMS-induced changes in CRF mRNA levels. Male rats were exposed to CMS for 19 days, and control animals were subjected to brief handling. Both groups were injected daily with tianeptine or saline. CMS significantly increased CRF mRNA levels in the dorsal BNST (dBNST), but not in other areas. Repeated tianeptine treatment prevented the CMS-induced increase in CRF mRNA levels in the dBNST, and reduced CRF mRNA levels in dBNST in non-stressed controls. Moreover, repeated tianeptine treatment significantly decreased CRF mRNA levels in the ventral BNST and CeA of non-stressed controls as well as CMS-exposed rats. These results show that CMS induces a rather selective increase of CRF mRNA in the dBNST. In addition, these results suggest that repeated tianeptine treatment diminishes the basal activity of CRF neurons and reduces their sensitivity to stress.

Chronic mild stress decreases survival, but not proliferation, of new-born cells in adult rat hippocampus.

New-born cells continue to proliferate and survive to become mature granule cells in adult rat hippocampus. Although this process, known as neurogenesis, is inhibited by acute stress, it is not clear whether chronic stress affects neurogenesis. To determine whether chronic mild stress (CMS) influences neurogenesis in the adult rat hippocampus, male Sprague-Dawley rats were exposed to CMS and administered bromodeoxyuridine (BrdU) before or after CMS to observe the survival/differentiation or proliferation of new-born cells, respectively. In addition, we measured brain-derived neurotrophic factor (BDNF) mRNA in the granule cell layer (GCL) of the hippocampus, because BDNF is known to play an important role in the survival of new-born cells. CMS significantly decreased the survival of new-born cells in the GCL, but did not influence the proliferation or differentiation of new-born cells. CMS did not affect the proliferation and survival of new-born cells in the hilus. In addition, CMS did not change BDNF mRNA levels in the GCL. These results demonstrate that CMS reduces the survival of new-born cells but not of their proliferation, suggesting that repeated mild stress could influence a part of neurogenesis, but not the whole part of neurogenesis. These results raise the possibility that the survival of new-born cells may be suppressed in the presence of normal BDNF mRNA levels in GCL.

Valproate prevents MK801-induced changes in brain-derived neurotrophic factor mRNA in the rat brain.

To investigate whether the anticonvulsant valproate influences the changes in brain-derived neurotrophic factor (BDNF) mRNA expression induced by MK801 in rat brain, we injected valproate prior to MK801 and observed the changes in the BDNF expression 3 h later. MK801 significantly increased BDNF expression in the retrosplenial and entorhinal cortex, and these increases were prevented by valproate pretreatment. Valproate pretreatment significantly blocked the MK801-induced increase of BDNF expression in retrosplenial cortex at 3 h, 6 h, and 9 h after MK801 injection, suggesting that valproate pretreatment did not delay the MK801-induced increase of BDNF expression. However, MK801 significantly decreased BDNF expression in the granule cell layer of hippocampus, and valproate pretreatment before MK801 potentiated the MK801-induced decrease in BDNF expression in granule cell layer. These results indicate that valproate pretreatment differentially affects the MK801-induced changes in BDNF expression in a region-selective manner.

Comparison of Blood Loss between Neutral Drainage with Tranexamic Acid and Negative Pressure Drainage without Tranexamic Acid Following Primary Total Knee Arthroplasty.

PURPOSE: There are many methods to reduce massive bleeding during total knee arthroplasty (TKA). In our study, tranexamic acid and neutral drainage were used to decrease total blood loss. MATERIALS AND METHODS: The study was performed on 97 TKA patients from March 2012 to January 2013. In the study group, tranexamic acid was administered and neutral drainage was applied. The study group had group I (unilateral, n=29) and group III (bilateral, n=17). The control group had group II (unilateral, n=35) and group IV (bilateral, n=16). RESULTS: In group I, the drainage volume on the 1st and 2nd postoperative days and the total drainage decreased with statistical significance (p<0.05). Between group III and group IV, group III had less drainage volume. In group III, the drainage volume on the 1st postoperative day and total drainage volume decreased statistically significantly (p<0.05). Between groups I and II, total blood loss showed no statistically significant difference, whereas between groups III and IV, the value was significantly different. CONCLUSIONS: Intravenous administration of tranexamic acid with neutral drainage for 3 postoperative hours is a recommendable method because it can be helpful in reducing total blood loss in bilateral TKA.

Doxapram increases corticotropin-releasing factor immunoreactivity and mRNA expression in the rat central nucleus of the amygdala.

Doxapram causes panic anxiety in humans. To determine whether doxapram alters corticotropin-releasing factor (CRF) expression in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), or bed nucleus of the stria terminalis (BNST), we used immunohistochemistry to measure CRF peptide in these brain areas after doxapram injection. Doxapram injection significantly increased CRF-like immunoreactivity (CRF-IR) within the CeA, but not in the BNST or PVN, and this increase was significant 2h after injection. In addition, doxapram significantly increased CRF mRNA expression within the CeA, and this was most prominent 30min after injection. These results suggest that doxapram selectively increases CRF expression within the CeA, and that this is mediated by increased CRF gene transcription. This increase in CRF-IR within the CeA might explain the doxapram-induced anxiety reaction.

Radiologic evaluation of degeneration in isthmic and degenerative spondylolisthesis.

STUDY DESIGN: A cross-sectional imaging study. PURPOSE: The objective was to assess the degree of degeneration and the associated factors through imaging studies of the lesion segment and the adjacent superior and inferior segments of isthmic and degenerative spondylolisthesis. OVERVIEW OF LITERATURE: Few articles existed for degeneration and related factors in isthmic and degenerative spondylolisthesis. METHODS: The subjects were 95 patients diagnosed with spondylolisthesis. Simple plain radiographs including flexion and extension and magnetic resonance imaging were used to investigate the degree of translation, disc degeneration, high intensity zone (HIZ) lesion, Schmorl's node (SN) and Modic changes. RESULTS: Advanced disc degeneration, grade 5, was shown to be significant in the index segment of the isthmic type (p=0.034). Overall, type 2 Modic change was most common in both groups and also, it was observed more in the isthmus group, specifically, the index segment compared to the degenerative group (p=0.03). For the SN, compared to the degenerative type, the isthmus type had a significantly high occurrence in the index segment (p=0.04). For the HIZ lesions, the isthmus type had a higher occurrence than the degenerative type, especially in the upper segment (p=0.03). CONCLUSIONS: Most advanced disc degeneration, fifth degree, SN and Modic change occurred more frequently in the lesions of the isthmus type. HIZ lesions were observed more in the isthmus type, especially in the segment superior to the lesion.

Comparison between Autogenous Bone Graft and Allogenous Cancellous Bone Graft in Medial Open Wedge High Tibial Osteotomy with 2-Year Follow-up.

PURPOSE: To compare the radiographic and clinical results of medial open wedge high tibial osteotomy (OWHTO) using autogenous bone graft and allogenous cancellous bone graft for medial compartment osteoarthritis of the knee with two-year follow-up. MATERIALS AND METHODS: Fifty-one patients (52 knees) who underwent medial OWHTO from October 2007 to April. 2010 were included in the study. The patients were divided into group I (n=29) that received an autogenous tricortical bone graft and group II (n=23) that received an allogenous cancellous bone chip graft. The radiographic parameters (preoperative anatomical and mechanical femorotibial angles, modified tibial bone varus angle, and posterior tibial slope), clinical parameters, bone union period, and complications were evaluated from medical records. RESULTS: The radiographic and clinical outcomes did not show significant difference between two groups. The average bone union period was 11.7 weeks in group I and 12.1 weeks in group II. The visual analog scale score on the first postoperative day was significantly higher in group I than group II. CONCLUSIONS: Medial OWHTO using allogenous cancellous bone graft for medial compartment osteoarthritis of the knee can be considered as an alternative treatment method that provides equivalent radiographic and clinical results of OWHTO using autogenous bone graft and causes less immediate postoperative pain.

Effects of repeated citalopram treatments on chronic mild stress-induced growth associated protein-43 mRNA expression in rat hippocampus.

Although growth associated protein-43 (GAP-43) is known to play a significant role in the regulation of axonal growth and the formation of new neuronal connections in the hippocampus, there is only a few studies on the effects of acute stress on GAP-43 mRNA expression in the hippocampus. Moreover, the effects of repeated citalopram treatment on chronic mild stress (CMS)-induced changes in GAP-43 mRNA expression in the hippocampus have not been explored before. To explore this question, male rats were exposed to acute immobilization stress or CMS. Also, citalopram was given prior to stress everyday during CMS procedures. Acute immobilization stress significantly increased GAP-43 mRNA expression in all subfields of the hippocampus, while CMS significantly decreased GAP-43 mRNA expression in the dentate granule cell layer (GCL). Repeated citalopram treatment decreased GAP-43 mRNA expression in the GCL compared with unstressed controls, but this decrease was not further potentiated by CMS exposure. Similar decreases in GAP-43 mRNA expression were observed in CA1, CA3 and CA4 areas of the hippocampus only after repeated citalopram treatment in CMS-exposed rats. This result indicates that GAP-43 mRNA expression in the hippocampus may differently respond to acute and chronic stress, and that repeated citalopram treatment does not change CMS-induced decreases in GAP-43 mRNA expression in the GCL.

Enhanced hypoglycemic activity following intratracheal administration of insulin microcrystal suspension with injection adjuvant.

The pulmonary route appears to be the most attractive alternative for non-invasive systemic delivery of insulin. We have shown the feasibility of insulin microcrystals as a long-acting formulation for pulmonary delivery. In this study, we examined the effects of adjuvant for pulmonary formulations of insulin, such as protamine, zinc, and glycerol. In an in vivo experiment with rats, only zinc enhanced the hypoglycemic effect of insulin microcrystals, with 17% of minimum reductions in blood glucose (%MRBG) and a 44% decrement in the blood glucose level (D%9h).