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Purpose@#While symptomatic basilar artery (BA) stenosis is associated with a higher risk of recurrent stroke or death, there is no consensus on the management of these patients who are refractory to antiplatelet therapy. This study retrospectively assesses the outcomes of endovascular treatment (EVT) for symptomatic BA stenosis. @*Materials and Methods@#We conducted a retrospective review of patients with symptomatic BA stenosis who underwent EVT, including angioplasty or stenting, from 2006 to 2018. A total of 15 patients, who experienced transient ischemic attacks or strokes despite dual antiplatelet therapy, were included. EVT was performed under local anesthesia after pretreatment with antiplatelet medications. Angiographic follow-up was performed at 12 and 24 months post-EVT. Clinical outcomes were evaluated using the modified Rankin Scale (mRS). @*Results@#EVT was successfully completed in all patients. Peri/post-procedural complications occurred in 33% of cases, including in-stent thrombosis, intracranial hemorrhage, and pontine infarction. At long-term follow-up (mean 98.5±80.5 months), 73.3% of patients achieved a favorable functional outcome (mRS≤2) without disability or mortality. Patients with unfavorable outcomes had previous infarcts, with 2 experiencing new pontine infarctions after stenting. @*Conclusion@#This study suggests that EVT, including angioplasty and stenting, may offer promise as a treatment option for symptomatic BA stenosis refractory to medical therapy. However, the procedure carries a notable risk of complications, especially in patients with severe stenosis and previous infarcts. Careful patient selection, based on clinical and radiological criteria, is crucial.
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Purpose@#Patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) and large vessel occlusion (LVO) often experience neurological deterioration >24 hours after onset. However, the efficacy of endovascular reperfusion therapy in these patients remains unclear. The aim of this study was to determine the efficacy and safety of reperfusion therapy in patients with minor stroke and neurological deterioration >24 hours after onset. @*Materials and Methods@#Data were retrospectively reviewed from patients between January 2019 and April 2022 who met the following criteria: (1) minor stroke and small definitive ischemic lesions at initial visit, (2) onset to neurological deterioration >24 hours, (3) cortical signs, Alberta Stroke Program Early computed tomography (CT) Score >6 points, and large artery occlusion confirmed by CT angiography at neurological deterioration. Efficacy and safety outcomes were based on final thrombolysis in cerebral infarction (TICI), incidence of symptomatic intracranial hemorrhage (ICH), and mortality. Outcomes were assessed using the modified Rankin Scale (mRS) at 3 months. Good outcome was defined as a mRS of 0, 1, or 2. @*Results@#Data from 26 patients (38.4% female, mean age 75.8 years) were analyzed; 18 (69.2%) had a good outcome. A final TICI of 2b or 3 was observed in 24 (92.3%) patients. No other adverse events, including dissection, vasospasm or distal embolization, were observed during the procedures. Hemorrhagic events occurred in 8 patients after the procedure; however, there were no symptomatic ICHs. Good prognostic factors were younger age (P=0.062) and carotid stenting (P=0.025). @*Conclusion@#Endovascular reperfusion therapy performed in selected patients with minor stroke, LVO, and neurological deterioration >24 hours after stroke onset demonstrated favorable outcomes and safety.
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Bilateral vertebral artery occlusive disease has been considered as a favorable condition with good collaterals. However, the prognosis of acute ischemic stroke secondary to symptomatic bilateral vertebral artery occlusion (BVAO) and endovascular treatment (EVT) has rarely been reported. We retrospectively selected patients with acute ischemic stroke admitted for symptomatic BVAO between January 2020 and February 2023. All patients with ischemic stroke were evaluated for ischemic lesion and arterial status using brain imaging and angiography. The prognosis of acute stroke with symptomatic BVAO was compared between EVT and conventional treatment. Outcomes were evaluated using modified Rankin Scale (mRS) score at 3 months follow-up. Within the study period, 17 of 2,655 acute ischemic stroke patients were diagnosed with ischemic stroke with symptomatic BVAO. The median age of these patients was 70 (interquartile range 44–89) years, and 13 (76%) were male. Seven patients received emergent EVT with stenting and 10 patients received conventional medical treatment only. Nine of 10 patients with conventional treatment had in-hospital stroke progression and developed new ischemic lesions in the pons and midbrain. Five patients with fetal and hypoplastic posterior communicating artery presented bilateral cerebral peduncular lesions. At 3 months follow-up, 6 patients (35%) had favorable outcomes (mRS 0–2), of which 5 were treated with vertebral artery stenting and 1 received conventional treatment. Ischemic stroke in patients with acute symptomatic BVAO is uncommon. However, stroke progression is common, and the prognosis of most patients is poor. Rescue management such as EVT might be considered for symptomatic BVAO.
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Purpose@#The purpose of this study was to evaluate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs), which can help establish guidelines of treatment for asymptomatic Korean adults using 3T magnetic resonance angiography (MRA). @*Materials and Methods@#Our Institutional Review Board approved this retrospective study, and informed consent was waived. All patients consisted of healthy individuals who underwent brain MRA using 3T magnetic resonance imaging between January 2011 and December 2012 as part of a routine health examination. Patient data and follow-up results were obtained from medical records. @*Results@#A total of 2,118 individuals (mean age=53.9±9.6 years, male:female=1,188:930) who had undergone brain MRA were enrolled in the study. UIAs were found in 80 patients with 105 UIAs (3.77%). Female predominance (55% in UIA vs. 43.47% in non-UIA, P=0.0416) and hypertension were more common in the UIA group (43.75% vs. 28.8%, P=0.004, respectively). The mean size of the aneurysms was 3.10±1.62 mm, and they were all saccular in shape and asymptomatic. The UIAs were most common in the internal carotid artery (59.1%), internal carotid-posterior communicating artery (15.2%), middle cerebral artery (9.5%), anterior communicating artery (8.6%), anterior cerebral artery (4.8%), and vertebral artery (2.9%). Twenty-eight of 80 patients (35%) had multiple aneurysms. The incidence of UIAs increased significantly with age (P=0.014). @*Conclusion@#In single center experience, we demonstrated the characteristics and prevalence of UIAs in asymptomatic adults, which may help establish guidelines or therapeutic standards for UIAs.
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Background and Objectives@#Large clinical studies of sodium/glucose cotransporter 2 (SGLT2) inhibitors have shown a significant beneficial effect on heart failure-associated hospitalization and cardiovascular events. As SGLT2 is known to be absent in heart cells, improved cardiovascular outcomes are thought to be accounted for by the indirect effects of the drug. We sought to confirm whether such benefits were mediated through SGLT2 expressed in the heart using myocardial infarction (MI) model. @*Methods@#Mice pre-treated with empagliflozin (EMPA), an SGLT2 inhibitor, showed a significantly reduced infarct size compared with the vehicle group three days post-MI.Interestingly, we confirmed SGLT2 localized in the infarct zone. The sequential changes of SGLT2 expression after MI were also evaluated. @*Results@#One day after MI, SGLT2 transiently appeared in the ischemic areas in the vehicle group and increased until 72 hours. The appearance of SGLT2 was delayed and less in amount compared with the vehicle group. Additionally, there was a significant difference in metabolites, including glucose and amino acids in the 1 H nuclear magnetic resonance analysis between groups. @*Conclusions@#Our work demonstrates that SGLT2 is transiently expressed in heart tissue early after MI and EMPA may directly operate on SGLT2 to facilitate metabolic substrates shifts.
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Purpose@#The purpose of this study was to evaluate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs), which can help establish guidelines of treatment for asymptomatic Korean adults using 3T magnetic resonance angiography (MRA). @*Materials and Methods@#Our Institutional Review Board approved this retrospective study, and informed consent was waived. All patients consisted of healthy individuals who underwent brain MRA using 3T magnetic resonance imaging between January 2011 and December 2012 as part of a routine health examination. Patient data and follow-up results were obtained from medical records. @*Results@#A total of 2,118 individuals (mean age=53.9±9.6 years, male:female=1,188:930) who had undergone brain MRA were enrolled in the study. UIAs were found in 80 patients with 105 UIAs (3.77%). Female predominance (55% in UIA vs. 43.47% in non-UIA, P=0.0416) and hypertension were more common in the UIA group (43.75% vs. 28.8%, P=0.004, respectively). The mean size of the aneurysms was 3.10±1.62 mm, and they were all saccular in shape and asymptomatic. The UIAs were most common in the internal carotid artery (59.1%), internal carotid-posterior communicating artery (15.2%), middle cerebral artery (9.5%), anterior communicating artery (8.6%), anterior cerebral artery (4.8%), and vertebral artery (2.9%). Twenty-eight of 80 patients (35%) had multiple aneurysms. The incidence of UIAs increased significantly with age (P=0.014). @*Conclusion@#In single center experience, we demonstrated the characteristics and prevalence of UIAs in asymptomatic adults, which may help establish guidelines or therapeutic standards for UIAs.
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Background and Objectives@#Large clinical studies of sodium/glucose cotransporter 2 (SGLT2) inhibitors have shown a significant beneficial effect on heart failure-associated hospitalization and cardiovascular events. As SGLT2 is known to be absent in heart cells, improved cardiovascular outcomes are thought to be accounted for by the indirect effects of the drug. We sought to confirm whether such benefits were mediated through SGLT2 expressed in the heart using myocardial infarction (MI) model. @*Methods@#Mice pre-treated with empagliflozin (EMPA), an SGLT2 inhibitor, showed a significantly reduced infarct size compared with the vehicle group three days post-MI.Interestingly, we confirmed SGLT2 localized in the infarct zone. The sequential changes of SGLT2 expression after MI were also evaluated. @*Results@#One day after MI, SGLT2 transiently appeared in the ischemic areas in the vehicle group and increased until 72 hours. The appearance of SGLT2 was delayed and less in amount compared with the vehicle group. Additionally, there was a significant difference in metabolites, including glucose and amino acids in the 1 H nuclear magnetic resonance analysis between groups. @*Conclusions@#Our work demonstrates that SGLT2 is transiently expressed in heart tissue early after MI and EMPA may directly operate on SGLT2 to facilitate metabolic substrates shifts.
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Objective@#Human adipose tissue-derived mesenchymal stem cells (ASCs) have been reported to promote angiogenesis and tissue repair. However, poor survival and engraftment efficiency of transplanted ASCs are the major bottlenecks for therapeutic application. The present study aims to improve the therapeutic efficacy of ASCs for peripheral artery diseases. @*Methods@#Hydrogen peroxide (H2O2) was used to induce apoptotic cell death in ASCs.To measure apoptosis, we used flow cytometry-based apoptosis analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. A murine hindlimb ischemia model was established to measure the ASC-mediated therapeutic angiogenesis and in vivo survival ability of ASCs. @*Results@#We identified that the inhibitor of lamin A-progerin binding, JH4, protects ASCs against H2O2-induced oxidative stress and apoptosis. Co-administration of ASCs with JH4 improved ASC-mediated blood reperfusion recovery and limb salvage compared to that of the control group in a mouse hind limb ischemia model. Immunofluorescence showed that JH4 treatment potentiated ASC-mediated vascular regeneration via reducing ASC apoptosis post transplantation. @*Conclusion@#JH4 exerts anti-apoptotic effects in ASCs in conditions of oxidative stress, and contributes to the repair of ischemic hind limb injury by improving cell survival.
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Stem cells are undifferentiated multipotent precursor cells that are capable both of perpetuating themselves as stem cells (self-renewal) and of undergoing differentiation into one or more specialized types of cells. And these stem cells have been reported to reside within distinct anatomic locations termed “niches”. The long-term goals of stem cell biology range from an understanding of cell-lineage determination and tissue organization to cellular therapeutics for degenerative diseases. Stem cells maintain tissue function throughout an organism’s lifespan by replacing differentiated cells. To perform this function, stem cells provide a unique combination of multilineage developmental potential and the capacity to undergo self-renewing divisions. The loss of self-renewal capacity in stem cells underlies certain degenerative diseases and the aging process. This self-renewal regulation must balance the regenerative needs of tissues that persist throughout life. Recent evidence suggests lysophosphatidic acid (LPA) signaling pathway plays an important role in the regulation of a variety of stem cells. In this review, we summarize the evidence linking between LPA and stem cell regulation. The LPA-induced signaling pathway regulates the proliferation and survival of stem cells and progenitors, and thus are likely to play a role in the maintenance of stem cell population in the body. This lipid mediator regulatory system can be a novel potential therapeutics for stem cell maintenance.
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Remote intracerebral hemorrhage (ICH) is defined as an ICH that occurs at a distant site from the treated lesion and is a considerable post-neurointerventional complication. Because such a life-threatening complication should not be neglected, we report our experience with delayed remote ICH in a patient with symptomatic intracranial atherosclerotic stenosis (ICAS) treated by Wingspan stenting following on-label usage guidelines. A middle-aged person suffered a lobar-type subcortical hemorrhage on the left temporal lobe 22 days after Wingspan stenting in the left internal carotid artery. The present case seemed to correspond with a previous report in which remote ICH tended to occur as an ipsilateral lobar-type hemorrhage in patients with unruptured intracranial aneurysm on the internal carotid artery undergoing treatment with stents or flow diverters. Delayed remote ICH should be considered as a potential risk of using a Wingspan stent covering the carotid siphon for ICAS.
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Background@#Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. @*Methods@#Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets’ conductor surface and content, insulator weight, and thermal deformation temperature. @*Results@#Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 °C. In relation to the installation year (30 years), insulation resistance decreased from 70 °C, which is as much as 40 °C lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. @*Conclusion@#The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 °C of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 °C. It is necessary to manage electrical socket outlets that have been installed for a long time.
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Background@#Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. @*Methods@#Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets’ conductor surface and content, insulator weight, and thermal deformation temperature. @*Results@#Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 °C. In relation to the installation year (30 years), insulation resistance decreased from 70 °C, which is as much as 40 °C lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. @*Conclusion@#The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 °C of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 °C. It is necessary to manage electrical socket outlets that have been installed for a long time.
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OBJECTIVE: To find out whether levels of fibrin degradation products (FDP) and D-dimer are increased in breast cancer-related lymphedema (BCRL) as in many vascular diseases. FDP and D-dimer have been used in blood tests to help differentiate deep vein thrombosis in the diagnosis of lymphedema. Levels of FDP and D-dimer are often elevated in patients with BCRL. METHODS: Patients with BCRL (group I), non-lymphedema after breast cancer treatment (group II), and deep venous thrombosis (group III) from January 2012 to December 2016 were enrolled. Levels of FDP and D-dimer were measured in all groups and compared among groups. RESULTS: Mean values of FDP and D-dimer of group I were 5.614±12.387 and 1.179±2.408 μg/μL, respectively. These were significantly higher than their upper normal limits set in our institution. Levels of FDP or D-dimer were not significantly different between group I and group II. However, values of FDP and D-dimer in group III were significantly higher than those in group I. CONCLUSION: Values of FDP and D-dimer were much higher in patients with thrombotic disease than those in patients with lymphedema. Thus, FDP and D-dimer can be used to differentiate between DVT and lymphedema. However, elevated levels of FDP or D-dimer cannot indicate the occurrence of lymphedema.
Subject(s)
Humans , Breast Neoplasms , Breast , Diagnosis , Fibrin Fibrinogen Degradation Products , Fibrin , Hematologic Tests , Lymphedema , Vascular Diseases , Venous ThrombosisABSTRACT
In the present study, we aimed to determine the cause of surface film formation in three rice vinegars fermented using the traditional static fermentation method. The pH and total acidity of vinegar were 3.0–3.3 and 3.0–8.7%, respectively, and acetic acid was the predominant organic acid present. Colonies showing a clear halo on GYC medium were isolated from the surface film of all vinegars. Via 16S rDNA sequencing, all of the isolates were identified as Acetobacter pasteurianus. Furthermore, field-emission scanning electron microscopy analysis showed that the bacterial cells had a rough surface, were rod-shaped, and were ∼1 × 2 µm in size. Interestingly, cells of the isolate from one of the vinegars were surrounded with an extremely fine threadlike structure. Thus, our results suggest that formation of the surface film in rice vinegar was attributable not to external contamination, to the production of bacterial cellulose by A. pasteurianus to withstand the high concentrations of acetic acid generated during fermentation. However, because of the formation of a surface film in vinegar is undesirable from an industrial perspective, further studies should focus on devising a modified fermentation process to prevent surface film formation and consequent quality degradation.
Subject(s)
Acetic Acid , Acetobacter , Cellulose , DNA, Ribosomal , Fermentation , Hydrogen-Ion Concentration , Methods , Microscopy, Electron, ScanningABSTRACT
BACKGROUND: Single staining is commonly performed for practical pathologic diagnoses. However, this method is limited in its ability to specify cellular morphology and immunophenotype and often requires consumption of limited tissue. This study aimed to describe an optimized protocol for multiple in situ hybridization (ISH) and immunohistochemistry (IHC). METHODS: The quality of multistaining was evaluated by carefully changing each step of ISH and IHC in an angioimmunoblastic T-cell lymphoma (AITL) case on a Ventana BenchMark XT automated immunostainer. The optimized protocols were also performed using another immunostainer and in 15 cases of five Epstein-Barr virus (EBV)–associated malignancies using formalin-fixed paraffin-embedded tissue. RESULTS: The quality of various ISH-IHC staining protocols was semi-quantitatively evaluated. The best EBV-encoded RNA (EBER)-ISH/double IHC staining quality, equivalent to single staining, was obtained using the following considerations: initial EBER-ISH application, use of protease and antigen retrieval reagent (cell conditioning 1 [CC1] treatment time was minimized due to impact on tissue quality), additional baking/deparaffinization not needed, and reduced dilution ratio and increased reaction time for primary antibody compared with single immunostaining. Furthermore, shorter second CC1 treatment time yielded better results. Multiple staining was the best quality in another immunostainer and for different types of EBV-associated malignancies when it was performed in the same manner as for the Ventana BenchMark XT as determined for AITL. CONCLUSIONS: EBER-ISH and double IHC could be easily used in clinical practice with currently available automated immunostainers and adjustment of reagent treatment time, dilution ratio, and antibody reaction time.
Subject(s)
Benchmarking , Diagnosis , Herpesvirus 4, Human , Immunohistochemistry , In Situ Hybridization , Lymphoma, T-Cell , Methods , Reaction Time , RNAABSTRACT
BACKGROUND: Ovarian epithelial cancer (OEC) is the second-most common gynecologic malignancy. CD109 expression is elevated in human tumor cell lines and carcinomas. A previous study showed that CD109 expression is elevated in human tumor cell lines and CD109 plays a role in cancer progression. Therefore, this study aimed to determine whether CD109 is expressed in OEC and can be useful in predicting the prognosis. METHODS: Immunohistochemical staining for CD109 and reverse transcription-quantitative polymerase chain reaction was performed. Then we compared CD109 expression and chemoresistance, overall survival, and recurrence-free survival of OEC patients. Chemoresistance was evaluated by dividing into good-response group and poor-response group by the time to recurrence after chemotherapy. RESULTS: CD109 expression was associated with overall survival (p = .020), but not recurrence-free survival (p = .290). CD109 expression was not an independent risk factor for overall survival due to its reliability (hazard ratio, 1.58; p = .160; 95% confidence interval, 0.82 to 3.05), although we found that CD109 positivity was related to chemoresistance. The poor-response group showed higher rates of CD109 expression than the good-response group (93.8% vs 66.7%, p = .047). Also, the CD109 mRNA expression level was 2.88 times higher in the poor-response group as compared to the good-response group (p = .001). CONCLUSIONS: Examining the CD109 expression in patients with OEC may be helpful in predicting survival and chemotherapeutic effect.
Subject(s)
Humans , Cell Line, Tumor , Drug Therapy , Polymerase Chain Reaction , Prognosis , Recurrence , Risk Factors , RNA, MessengerABSTRACT
OBJECTIVE: To investigate association between lesion location on magnetic resonance imaging (MRI) performed after an infarction and the duration of dysphagia in middle cerebral artery (MCA) infarction. METHODS: A videofluoroscopic swallowing study was performed for 59 patients with dysphagia who were diagnosed as cerebral infarction of the MCA territory confirmed by brain MRI. Lesions were divided into 11 regions of interest: primary somatosensory cortex, primary motor cortex, supplementary motor cortex, anterior cingulate cortex, orbitofrontal cortex, parieto-occipital cortex, insular cortex, posterior limb of the internal capsule (PLIC), thalamus, basal ganglia (caudate nucleus), and basal ganglia (putamen). Recovery time was defined as the period from the first day of L-tube feeding to the day that rice porridge with thickening agent was prescribed. Recovery time and brain lesion patterns were compared and analyzed. RESULTS: The mean recovery time of all patients was 26.71±16.39 days. The mean recovery time was 36.65±15.83 days in patients with PLIC lesions and 32.6±17.27 days in patients with caudate nucleus lesions. Only these two groups showed longer recovery time than the average recovery time for all patients. One-way analysis of variance for recovery time showed significant differences between patients with and without lesions in PLIC and caudate (p<0.001). CONCLUSION: Injury to both PLIC and caudate nucleus is associated with longer recovery time from dysphagia.
Subject(s)
Humans , Basal Ganglia , Brain , Caudate Nucleus , Cerebral Cortex , Cerebral Infarction , Deglutition , Deglutition Disorders , Extremities , Gyrus Cinguli , Infarction , Infarction, Middle Cerebral Artery , Internal Capsule , Magnetic Resonance Imaging , Middle Cerebral Artery , Motor Cortex , Prefrontal Cortex , Somatosensory Cortex , ThalamusABSTRACT
BACKGROUND: To develop the biodegradability and thermoresponsive hydrogel, in this work we designed a pendant-functionalized, thermoresponsive, amphiphilic block copolymer. METHODS: Methoxy poly(ethylene glycol) (MPEG)-b-[poly(ε-caprolactone)-ran-poly(ε-caprolactone-3-one)-ran-polylactic acid] (MCL) and (MPEG-b-[PCL-ran-POD-ran-PLA]) [MCL-(CO)] block copolymers were prepared by ringopening polymerization of ε-caprolactone, OD and lactide monomers. The subsequent derivatization of MCL-(CO) provided MPEG-b-[PCL-ran-poly(ε-caprolactone-3-COOH)-ran-PLA] [MCL-(COOH)] with COOH pendant groups and MPEG-b-[PCL-ran-poly(ε-caprolactone-3-NH2)-ran-PLA] [MCL-(NH2)] with NH2 pendant groups. RESULTS: The measured segment ratios of MCL-(CO), MCL-(COOH), and MCL-(NH2) agreed well with the target ratios. The abundances of the COOH and NH2 groups in the MCL-(COOH) and MCL-(NH2) copolymers were determined by 1H- and 13C-nuclear magnetic resonance spectroscopy, and agreed well with the target abundances. MCL-(CO), MCL-(COOH), and MCL-(NH2) formed homogeneous, white, opaque emulsions at room temperature. Rheological analysis of the block copolymer suspensions indicated a solution-to-hydrogel phase transition as a function of temperature. The solution-to-hydrogel phase transitions and the biodegradation of MCL-(CO), MCL-(COOH), and MCL-(NH2) were affected by varying the type (ketone, COOH, or NH2) and abundance of the pendant groups. CONCLUSION: MCL-(CO), MCL-(COOH), and MCL-(NH2) with ketone, COOH, and NH2 pendant groups showed solution-to-hydrogel phase transitions and biodegradation behaviors that depended on both the type and number of pendant groups.
Subject(s)
Emulsions , Hydrogels , Magnetic Resonance Spectroscopy , Phase Transition , Polymerization , Polymers , SuspensionsABSTRACT
The aim of the present study was to evaluate the central antinociceptive effects of eugenol after intraperitoneal administration. Experiments were carried out using male Sprague-Dawley rats. Subcutaneous injection of 5% formalin-induced nociceptive behavioral responses was used as the pain model. Subcutaneous injection of 5% formalin significantly produced nociceptive responses by increasing the licking time during nociceptive behavior. Subsequent intraperitoneal injection of 100 mg/kg of eugenol led to a significant decrease in the licking time. However, low dose of eugenol (50 mg/kg) did not affect the nociceptive behavioral responses produced by subcutaneous injection of formalin. Intrathecal injection of 30 µg of naloxone, an opioid receptor antagonist, significantly blocked antinociceptive effects produced by intraperitoneal injection of eugenol. Neither intrathecal injection of methysergide (30 µg), a serotonin receptor antagonist nor phentolamine (30 µg), an α-adrenergic receptor antagonist influenced antinociceptive effects of eugenol, as compared to the vehicle treatment. These results suggest that central opioid pathway participates in mediating the antinociceptive effects of eugenol.