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1.
Libyan J Med ; 18(1): 2182683, 2023 Dec.
Article in English | MEDLINE | ID: mdl-36855243

ABSTRACT

Etomidate is an anesthetic agent used in hemodynamically unstable patients, but its use has been controversial in septic patients. The response of high-mobility group box 1 (HMGB1), a late-phase lethal cytokine in sepsis, to etomidate has not been reported. This study investigated the effects of etomidate on the expression and release of HMGB1 and the underlying mechanism using a cecal ligation and puncture (CLP) model. Thirty-six male Sprague-Dawley rats were divided into sham, CLP, and Etomi groups. Sepsis was induced in the CLP and Etomi groups, and intravenous etomidate (4 mg/kg) was infused for 40 min immediately after operation in the Etomi group. Serum creatinine, alanine aminotransferase (ALT), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and HMGB1 levels were measured 6 and 24 hours after surgery. Activation of nuclear factor (NF)-ĸB and HMGB1 mRNA expression in the liver, lung, kidney, and ileum tissues were measured, and immunohistochemical staining of HMGB1 was implemented. Increases of the TNF-α level 6 h after CLP and ALT and IL-6 levels 24 h after CLP were significantly inhibited by etomidate treatment. Etomidate treatment also significantly attenuated the increase in serum HMGB1 level at 6 and 24 h after CLP and suppressed the NF-ĸB and HMGB1 mRNA in multiple organs 24 h after CLP. Immunohistochemical staining also revealed that etomidate treatment inhibited HMGB1 expression. Etomidate inhibited the systemic release of HMGB1 and its expression in various organs. The mechanism may be associated with the inhibitory effects of etomidate on pro-inflammatory cytokine release and NF-ĸB activity.


Subject(s)
Etomidate , HMGB1 Protein , Sepsis , Male , Rats , Animals , NF-kappa B , Etomidate/pharmacology , Rats, Sprague-Dawley , Sepsis/drug therapy , Cytokines , Interleukin-6
2.
Medicina (Kaunas) ; 58(7)2022 Jul 15.
Article in English | MEDLINE | ID: mdl-35888659

ABSTRACT

Background and Objectives: The effect of positive end-expiratory pressure (PEEP) on intraocular pressure (IOP) is debatable. There have been no studies investigating the effects of PEEP on IOP during one-lung ventilation (OLV). We aimed to investigate the effects of PEEP on IOP in patients undergoing OLV for video-assisted thoracoscopic surgery (VATs). Materials and Methods: Fifty-two patients undergoing VATs were divided into a zero-PEEP (ZEEP) and a 6 cmH2O of PEEP (PEEP) groups. IOP, ocular perfusion pressure (OPP), and respiratory and hemodynamic parameters were measured before induction (T1), immediately following endotracheal intubation (T2), 30 min (T3) and 60 min (T4) after a position change to the lateral decubitus position (LDP) and OLV, and 10 min following two-lung ventilation near the end of the surgery (T5). Results: There was no significant difference in IOP and OPP between the two groups. The IOP of the dependent eye was significantly higher than that of the non-dependent eye during LDP in both groups. Peak inspiratory pressure was significantly higher in the PEEP group than in the ZEEP group at T3-T5. Dynamic compliance was significantly higher in the PEEP group than in the ZEEP group at T2-T5. The ratio of arterial oxygen partial pressure to fractional inspired oxygen was significantly higher in the PEEP group than in the ZEEP group at T4. Conclusions: Applying 6 cmH2O of PEEP did not increase IOP but enhanced dynamic compliance and oxygenation during OLV. These results suggest that 6 cmH2O of PEEP can be safely applied during OLV in LDP.


Subject(s)
One-Lung Ventilation , Humans , Intraocular Pressure , One-Lung Ventilation/methods , Oxygen , Positive-Pressure Respiration/methods , Prospective Studies
3.
Nanomaterials (Basel) ; 12(5)2022 Feb 23.
Article in English | MEDLINE | ID: mdl-35269241

ABSTRACT

This work presents a novel approach to synthesizing magnetic core-shell nanocomposites, consisting of magnetic nanoparticles and a metal-organic framework, for environmental applications. The synthesis is based on the encapsulation of magnetic Fe3O4 nanoparticles with microporous zeolitic imidazolate framework-8 (ZIF-8) nanocrystals via ultrasonic activation under a continuous supply of precursor solutions. This sonochemical approach is proven to be a fast, cost-effective, and controllable route for the preparation of magnet-responsive Fe3O4@ZIF-8 nanoparticles with a core-shell structure. The functional nanomaterial possesses a high content of ZIF-8 and combined micro/mesoporosity, and thus can be used as adsorbents that can be easily separated using a magnet. In particular, the sonochemically prepared Fe3O4@ZIF-8 exhibits significant adsorption performance for the removal of copper ions from water: a short adsorption time (10 min), high maximum uptake capacity (345 mg g-1), and excellent removal efficiency (95.3%). These performances are interpreted and discussed based on the materials characteristics of Fe3O4@ZIF-8 established by microscopy, gas sorption, X-ray diffraction, and thermal analysis.

4.
Nanomaterials (Basel) ; 11(2)2021 Feb 02.
Article in English | MEDLINE | ID: mdl-33540534

ABSTRACT

Naturally abundant vermiculite clay was expanded by using an aqueous solution of H2O2 and its surface was modified with ultra-thin polydimethylsiloxane (PDMS) using facile thermal vapor deposition to prepare an ecologically friendly, low-cost oil sorbent that plays an important role in oil spillage remediation. The resulting PDMS-coated expanded vermiculite (eVMT@PDMS) particles exhibited adequate hydrophobicity and oleophilicity for oil/water separation, with numerous conical slit pores (a size of 0.1-100 µm) providing a great sorption capacity and an efficient capillarity-driven flow pathway for oil collection. Simply with using a physically-packed eVMT@PDMS tube (or pouch), selective oil removals were demonstrated above and beneath the surface of the water. Furthermore, these sorbents were successfully integrated and then applied to the advanced oil-collecting devices such as a barrel-shaped oil skimmer and a self-primed oil pump.

5.
Medicine (Baltimore) ; 98(18): e15461, 2019 May.
Article in English | MEDLINE | ID: mdl-31045821

ABSTRACT

PURPOSE: The aim of the present study is to evaluate the effects of deliberate hypotensive anesthesia on intraocular pressure (IOP) and ocular perfusion pressure (OPP) and compare the effects of propofol total intravenous anesthesia (TIVA) and desflurane anesthesia on IOP and OPP. METHODS: A total of 50 patients undergoing arthroscopic shoulder surgery in the lateral decubitus position were randomized to receive desflurane or propofol anesthesia. Mean arterial pressure (MAP) was maintained in the range of 60-75 mm Hg during hypotensive anesthesia. IOP was measured using a handheld tonometer at 7 time points: before induction (T1, baseline); immediately after endotracheal intubation (T2); 10 minutes after position change to lateral decubitus (T3); 10, 30, and 50 minutes after the start of hypotensive anesthesia (T4-T6); and at the end of surgery (T7). RESULTS: MAP decreased about 35% to 38% during hypotensive anesthesia. Compared to baseline values, the IOP at T6 in dependent and non-dependent eyes decreased by 0.43 and 2.74 mm Hg, respectively in desflurane group; 3.61 and 6.05 mm Hg, respectively in the propofol group. IOP of both eyes in the propofol group was significantly lower than in the desflurane group from T2 to T7. OPP of both eyes in both groups was significantly lower than at baseline, except at T2 in the desflurane group. OPP of both eyes in the propofol group was significantly higher than that in the desflurane group at T5 and T6. CONCLUSIONS: Hypotensive anesthesia reduced IOP and OPP, but propofol TIVA maintained higher OPP than desflurane anesthesia. These findings suggest that propofol TIVA can help mitigate the decrease of OPP during hypotensive anesthesia.


Subject(s)
Anesthetics, Intravenous/administration & dosage , Desflurane/administration & dosage , Hypotension, Controlled/methods , Intraocular Pressure/drug effects , Propofol/administration & dosage , Aged , Arterial Pressure/drug effects , Arthroscopy/methods , Eye/blood supply , Female , Humans , Male , Middle Aged , Prospective Studies , Shoulder/surgery , Tonometry, Ocular , Treatment Outcome
6.
Korean J Anesthesiol ; 72(1): 60-67, 2019 02.
Article in English | MEDLINE | ID: mdl-29969887

ABSTRACT

BACKGROUND: The pain-relief properties of tricyclic antidepressants can be attributed to several actions. Recent observations suggest that adenosine is involved in the antinociceptive effect of amitriptyline. The A3 adenosine receptor (A3AR) is the only adenosine subtype overexpressed in inflammatory and cancer cells. This study was performed to investigate the role of A3AR in the anti-nociceptive effect of amitriptyline. METHODS: Spinal nerve-ligated neuropathic pain was induced by ligating the L5 and L6 spinal nerves of male Sprague-Dawley rats. The neuropathic rats were randomly assigned to one of the following three groups (8 per group): a neuropathic pain with normal saline group, a neuropathic pain with amitriptyline group, and a neuropathic pain with amitriptyline and 3-ethyl-5-benzyl- 2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS) group. Amitriptyline or saline was administered intraperitoneally and 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS-1191), an A3AR antagonist, was injected subcutaneously immediately before amitriptyline administration. The level of extracellular signal-regulated kinase P44/42 (ERK1/2), cyclic AMP response element-binding protein (CREB), and proinflammatory cytokines were assessed using immunoblotting or reverse-transciption polymerase chain reaction. RESULTS: Amitriptyline increased the mechanical withdrawal threshold of the neuropathic rats. The level of phospho-ERK1/2 and phospho-CREB proteins, and proinflammatory cytokines produced by spinal nerve ligation were significantly reduced by amitriptyline administration. However, the use of MRS-1191 before amitriptyline administration not only reduced the threshold of mechanical allodynia, but also increased the signaling protein and proinflammatory cytokine levels, which were reduced by amitriptyline. CONCLUSIONS: The results of this study suggest that the anti-nociceptive effect of amitriptyline involves the suppression of ERK1/2 and CREB signaling proteins, and A3AR activation also affects the alleviation of the inflammatory response.


Subject(s)
Amitriptyline/pharmacology , Cyclic AMP Response Element-Binding Protein/antagonists & inhibitors , Cytokines/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , MAP Kinase Signaling System/drug effects , Neuralgia/drug therapy , Receptor, Adenosine A3/physiology , Adenosine A3 Receptor Antagonists/pharmacology , Animals , Cyclic AMP Response Element-Binding Protein/physiology , Disease Models, Animal , Extracellular Signal-Regulated MAP Kinases/physiology , Male , Rats , Rats, Sprague-Dawley
7.
Medicine (Baltimore) ; 97(16): e0440, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29668608

ABSTRACT

BACKGROUND: Adjuvant perineural dexmedetomidine can be used to prolong the analgesic effect of interscalene brachial plexus block (ISB). We investigated the optimal dose of dexmedetomidine in ISB for postoperative analgesia in patients undergoing arthroscopic shoulder surgery. METHODS: One hundred patients scheduled for elective shoulder arthroscopic surgery were enrolled in this randomized, double-blind study. Ultrasound-guided ISB was performed before general anesthesia using 22 mL of ropivacaine 0.5% combined with 1, 1.5, or 2 µg/kg of dexmedetomidine (group D1, D2, and D3, respectively) or with normal saline as a control (group R, n = 25 per group). The primary outcome was the duration of analgesia (DOA), numeric pain rating scale (NRS), and consumption of additional analgesics during 36 h after ISB. Secondary outcome included durations of motor and sensory block (DOM and DOS), hemodynamic variables and sedation and dyspnea scores. RESULTS: Ninety-seven patients completed the study. The DOS, DOM, and DOA were significantly longer in the dexmedetomidine groups than in group R. The DOA was significantly longer in group D3 than in groups D1 (P = .026) and D2 (P = .039). The DOA was 808.13 ±â€Š179.97, 1032.60 ±â€Š288.14, 1042.04 ±â€Š188.13, and 1223.96 ±â€Š238.06 min in groups R, D1, D2, and D3, respectively. The NRS score was significantly higher in group R than in the dexmedetomidine groups 12 h after ISB (P < .001) and significantly lower in group D3 than in the other groups 18 h after ISB (P = .02). The incidence of hypotension was higher in groups D2 and D3 than in group R during surgery (P = .008 and P = .011, respectively). There were no significant differences in consumption of rescue analgesics, sedation, and dyspnea scores between the study groups. CONCLUSION: Perineural dexmedetomidine 2 µg/kg could be the optimal dose in ISB for arthroscopic shoulder surgery in that it provides an adequate DOA. However, this dose was associated with increased risk of hypotension.


Subject(s)
Analgesics, Non-Narcotic/administration & dosage , Arthroscopy/adverse effects , Brachial Plexus Block/methods , Dexmedetomidine/administration & dosage , Pain, Postoperative/prevention & control , Shoulder/surgery , Aged , Analgesics, Non-Narcotic/adverse effects , Dexmedetomidine/adverse effects , Double-Blind Method , Female , Hemodynamics , Humans , Hypotension/chemically induced , Male , Middle Aged , Prospective Studies
8.
J Clin Monit Comput ; 32(6): 1101-1109, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29457191

ABSTRACT

Laparoscopic surgery is often prolonged and requires positional changes to facilitate surgical access. Previous studies reported intraocular pressure (IOP) changes in one fixed position. This study investigated the effect of desflurane and propofol anesthesia on IOP during repeated positional changes. A total of 46 patients undergoing laparoscopic colorectal surgery were randomized into desflurane or propofol groups. IOP was measured using a handheld tonometer at seven time points: before induction (baseline), after endotracheal intubation, after pneumoperitoneum, after the first Trendelenburg and right tilt position, after reverse Trendelenburg and right tilt position, after the second Trendelenburg and right tilt position and before endotracheal extubation. Trendelenburg positioning raised IOP in both groups. In the desflurane group, IOP at the first Trendelenburg position was 6.27 and 8.48 mmHg higher than baseline IOP in left and right eye, respectively; IOP at the second Trendelenburg position was 7 and 9.44 mmHg higher than baseline in left and right eye, respectively. In the propofol group, IOP at the first Trendelenburg position was 2.04 and 4.04 mmHg higher than baseline in left and right eyes, respectively. It was 3.04 and 4.87 mmHg higher than baseline in left and right eye, respectively, at the second Trendelenburg position. In the desflurane group, 56.52% patients exhibited high IOP (≥ 25 mmHg) compared with 13.04% in the propofol group at the second Trendelenburg position in the right eyes (P = 0.005). There was a positive correlation between IOP and peak inspiratory pressure (P < 0.001). Propofol anesthesia mitigated wide variations in IOP caused by repetitive positional changes during laparoscopic colorectal surgery.


Subject(s)
Anesthetics, Inhalation/adverse effects , Desflurane/adverse effects , Intraocular Pressure/drug effects , Patient Positioning/adverse effects , Propofol/adverse effects , Aged , Anesthetics, Intravenous/adverse effects , Digestive System Surgical Procedures/methods , Female , Head-Down Tilt/adverse effects , Humans , Laparoscopy/methods , Male , Middle Aged , Monitoring, Intraoperative , Posture , Prospective Studies , Tonometry, Ocular
9.
Sens Actuators B Chem ; 255(3): 3654-3661, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29180835

ABSTRACT

Numerous fabrication methods have been reported for microfluidic paper-based analytical devices (µPADs) using barrier materials ranging from photoresist to wax. While these methods have been used with wide success, consistently producing small, high-resolution features using materials and methods that are compatible with solvents and surfactants remains a challenge. Two new methods are presented here for generating µPADs with well-defined, high-resolution structures compatible with solvents and surfactant-containing solutions by partially or fully fusing paper with Parafilm® followed by cutting with a CO2 laser cutter. Partial fusion leads to laminated paper (l-paper) while the complete fusion results in infused paper (i-paper). Patterned structures in l-paper were fabricated by selective removal of the paper but not the underlying Parafilm® using a benchtop CO2 laser. Under optimized conditions, a gap as small as 137 ± 22 µm could be generated. Using this approach, a miniaturized paper 384-zone plate, consisting of circular detection elements with a diameter of 1.86 mm, was fabricated in 64 × 43 mm2 area. Furthermore, these ablation-patterned substrates were confirmed to be compatible with surfactant solutions and common organic solvents (methanol, acetonitrile and dimethylformamide), which has been achieved by very few µPAD patterning techniques. Patterns in i-paper were created by completely cutting out zones of the i-paper and then fixing pre-cut paper into these openings similar to the strategy of fitting a jigsaw piece into a puzzle. Upon heating, unmodified paper was readily sealed into these openings due to partial reflow of the paraffin into the paper. This unique and simple bonding method was illustrated by two types of 3D µPADs, a push-on valve and a time-gated flow distributor, without adding adhesive layers. The free-standing jigsaw-patterned sheets showed good structural stability and solution compatibility, which provided a facile alternative method for fabricating complicated µPADs.

10.
J Int Med Res ; 42(5): 1139-49, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25004921

ABSTRACT

OBJECTIVE: To investigate the optimal dose of dexmedetomidine for attenuating the haemodynamic response during emergence from anaesthesia. METHODS: Patients undergoing laparoscopic total hysterectomy were randomly allocated to receive 0.9% normal saline (control group) or dexmedetomidine (0.5 µg/kg, 0.75 µg/kg or 1.0 µg/kg 30 min) before extubation. Heart rate, systolic and diastolic arterial pressure and extubation time were measured before drug administration, immediately after the end of drug administration, 10 min after the end of drug administration, immediately after extubation and 5 min after extubation. RESULTS: A total of 120 patients were included in the study (30 per group). Systolic and diastolic arterial pressure and heart rate after drug administration were significantly lower in all three dexmedetomidine groups compared with controls. Extubation times in the 0.75 and 1.0 µg/kg dexmedetomidine groups were significantly longer than in the control group. CONCLUSION: Intravenous infusion of 0.5 µg/kg dexmedetomidine 30 min before the end of surgery attenuated the haemodynamic responses during emergence without prolonging the extubation time. Dexmedetomidine doses higher than 0.5 µg/kg did not exert additional positive effects on cardiovascular responses, but did significantly prolong the extubation time.


Subject(s)
Anesthesia Recovery Period , Blood Pressure/drug effects , Dexmedetomidine/administration & dosage , Heart Rate/drug effects , Hemodynamics/drug effects , Hypnotics and Sedatives/administration & dosage , Hysterectomy , Laparoscopy , Adolescent , Adult , Airway Extubation , Female , Follow-Up Studies , Humans , Intubation, Intratracheal , Middle Aged , Prognosis , Young Adult
11.
Pain Physician ; 17(3): E381-4, 2014.
Article in English | MEDLINE | ID: mdl-24850128

ABSTRACT

A 39-year-old woman with no history of trauma or meningitis presented to the neurology department of our hospital with an occipital headache, neck pain, nausea, and dizziness that had worsened during the previous month. The headache worsened when sitting or standing and partially regressed when lying down. She was diagnosed with spontaneous intracranial hypotension (SIH) and received conservative management. After failing to respond to conservative management, she underwent an autologous epidural blood patch (EBP) at the T7-8 level. The headache and associated symptoms did not improve after the procedure. Magnetic resonance (MR) myelography suggested a cerebrospinal fluid leakage at the C1-2 level resulting in intracranial hypotension. An 18-gauge Tuohy needle was inserted at the T1-2 interlaminal level using a paramedian approach under fluoroscopic guidance. The cervical epidural Racz catheter was threaded through the Tuohy needle up to the cervical spine and the catheter tip was confirmed to be at the right cervical 1-2 site on an anteroposterior (AP) view. Five mL of autologous blood was injected into the epidural space through the cervical epidural Racz catheter. Her occipital headache and associated symptoms gradually disappeared after the procedure. Seven days later the headache was largely resolved and she was discharged. Follow-up magnetic resonance imaging (MRI) showed the disappearance of abnormal radiological features associated with intracranial hypotension. She currently remains symptom free for 9 months. Delivery of autologous blood patch via a cervical epidural Racz catheter inserted from the upper thoracic spine can be a safe and effective method for patients with SIH due to cerebrospinal fluid (CSF) leakage in the upper cervical spine.


Subject(s)
Blood Patch, Epidural/methods , Cerebrospinal Fluid Leak/therapy , Adult , Catheters , Epidural Space , Female , Headache/complications , Headache/drug therapy , Humans , Intracranial Hypotension/complications , Intracranial Hypotension/therapy , Thoracic Vertebrae
13.
J Nanosci Nanotechnol ; 13(9): 6249-53, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24205639

ABSTRACT

In this work, we propose a novel chemoresistive gas sensor operated under a vertical analyte flow passing through a permeable sensing membrane. Such a configuration is different from the use of a planar sensor implemented under a conventional horizontal flow. A highly porous core-shell polyacrylonitrile-polypyrrole (PAN@PPy) nanofiber mat was prepared as the sensing element via electrospinning and two-step vapor-phase polymerization (VPP). Various analysis methods such as SEM, TEM, FT-IR and XPS measurements were employed in order to characterize structural features of the porous sensing mat. These analyses confirmed that very thin (ca. 10 nm) conductive PPy sheath layers were deposited by VPP on electrospun PAN nanofibers with an average diameter of 258 nm. Preliminary results revealed that the gas penetration-type PAN@PPy sensor had a higher sensor response and shorter detection and recovery times upon exposure to methanol analyte when compared with a conventional horizontal flow sensor due to efficient and fast analyte transfer into the sensing layer.


Subject(s)
Acrylic Resins/chemistry , Methanol/analysis , Nanofibers , Polymers/chemistry , Pyrroles/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Photoelectron Spectroscopy , Spectroscopy, Fourier Transform Infrared
14.
Int J Med Sci ; 10(10): 1327-32, 2013.
Article in English | MEDLINE | ID: mdl-23983593

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the optimum dosage of dexmedetomidine for prevention of postanesthetic shivering. METHODS: One-hundred thirty two ASA physical status I-II patients scheduled for elective laparoscopic total hysterectomy were enrolled in this randomised, placebo-controlled study. Patients were randomly allocated to receive dexmedetomidine in four groups: group S (0.9% normal saline), group D0.5 (dexmedetomidine 0.5 µg/kg), group D0.75 (dexmedetomidine 0.75 µg/kg), group D1.0 (dexmedetomidine 1.0 µg/kg). Time to extubation and tympanic temperature during and after operation were measured. Shivering was graded (0-3 scale) upon patients arrival to the PACU and every ten minutes thereafter up to forty minutes. Sedation and first rescue analgesic time at the PACU were evaluated. RESULTS: The incidence of shivering was significantly lower in group D0.75 and D1.0 than in group S (P < 0.05). There were significantly fewer patients with a shivering score of 2 or 3 in groups D0.75 and D1.0 than in group S (P < 0.05, P < 0.001). Extubation time was shorter in group S than in groups D0.75 and D1.0 (P < 0.05). Tympanic temperature at 40 minutes postoperatively in the recovery room was higher in group S than in the other dexmedetomidine groups (P < 0.05) Fewer patients required rescue analgesia in groups D0.75 and D1.0 than in group S (P < 0.001), and the time to rescue analgesia was longer in group D1.0 than in group S (P < 0.001). Modified Observer's Assessment of Alertness/Sedation (MOAA/S) at arrival in the PACU was lower in all dexmedetomidine groups than in group S (P < 0.05). CONCLUSIONS: Our results suggest that dexmedetomidine 0.75 or 1.0 µg/kg provides effective prophylaxis against postoperative shivering as well as an analgesic effect. Though potential for intraoperative requirement for atropine, sedation in the immediate recovery period and delayed extubation time with dexmedetomidine was noted, there were no major clinical impacts on the overall recovery from anesthesia.


Subject(s)
Analgesia/adverse effects , Dexmedetomidine/therapeutic use , Shivering/drug effects , Adult , Female , Humans , Hysterectomy , Middle Aged
15.
J Nanosci Nanotechnol ; 13(5): 3627-33, 2013 May.
Article in English | MEDLINE | ID: mdl-23858916

ABSTRACT

Platinum nanoparticles (Pt NPs) were chemically deposited on a Nafion polymer electrolyte membrane by the impregnation-reduction (I-R) procedure to prepare an active electrode for solid electrochemical sensors. Various analysis methods such as SEM, EDX, XRD and cyclic voltammogram (CV) measurements were employed in order to characterize microstructures and electrochemical properties of the Pt layer. At the conditions ([Pt(NH3)4Cl2] = 10 mM, [NaBH4] = 60 mM, 50 degrees C), the porous Pt thin-film, consisting of sphere-like particles formed by the agglomeration of primary polycrystalline Pt NPs with an average crystal size of 13-18 nm, was obtained and confirmed to have a large surface area (roughness factor = 267) and strong adhesion due to the formation of interfacial Pt-Nafion composites. The secondary globular particles were found to have an average diameter of 215 nm and irregular protuberances on the surface. Furthermore, this electrode exhibited well-resolved CV peaks for the hydrogen redox reactions in an acid solution, suggesting the existence of different adsorption sites and good electrochemical behaviors. Pt/Nafion electrodes were prepared under different conditions in [Pt(NH3)4Cl2], [NaBH4] and reaction temperature, and their material properties were discussed from the viewpoint of a Pt growth mechanism.


Subject(s)
Electrodes , Fluorocarbon Polymers/chemistry , Membranes, Artificial , Nanostructures/chemistry , Nanostructures/ultrastructure , Platinum/chemistry , Adhesiveness , Electric Conductivity , Electroplating , Equipment Design , Equipment Failure Analysis , Materials Testing , Oxidation-Reduction , Particle Size , Surface Properties
16.
J Nanosci Nanotechnol ; 12(7): 5967-71, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22966690

ABSTRACT

Nonwoven polyacrylonitrile-polypyrrole (PAN-PPy) core-shell nanofiber mats were prepared through the growth of PPy layers on electrospun PAN nanofibers via a two-step vapor-phase polymerization, i.e., the wet-coating of ferric tosylate (FeTos) oxidants on PAN nanofibers followed by exposure to pyrrole monomers in the gas phase. Under the conditions ([FeTos] = 10 wt%, reaction time = 15 min, temperature = 15 degrees C), the PPy polymerization procedure led to both a uniform coating over the PAN surface with an average thickness of 18 nm and cross-linkages among the nanofibers without a noticeable change in the highly porous nanofibrous structures. The oxidant concentration and polymerization time were found to be key parameters for achieving a good nanostructured core-shell fiber mat. FT-IR, XPS, XRD and conductivity measurements confirmed the synthesis of Tos-doped PPy with some degree of crystallinity and a high conductivity.

17.
J Korean Med Sci ; 27(5): 547-52, 2012 May.
Article in English | MEDLINE | ID: mdl-22563222

ABSTRACT

We previously demonstrated that there are acute and delayed phases of renal protection against renal ischemia and reperfusion (IR) injury with renal ischemic preconditioning (IPC). This study assessed whether hepatic IPC could also reduce distant renal IR injury through the blood stream-mediated supply of reactive oxygen species (ROS). Male C57BL/6 mice were randomly divided into four groups: group I, sham operated including right nephrectomy; group II (IR), left renal ischemia for 30 min and reperfusion injury; group III (IPC-IR), hepatic ischemia for 10 min followed by 10 min of reperfusion before left renal IR injury; group IV (MPG - IPC + IR), pretreated with 100 mg/kg N-(2-mercaptopropionyl)-glycine (MPG) 15 min before hepatic IPC and left renal IR injury. Renal function, histopathologic findings, proinflammatory cytokines, and cytoprotective proteins were evaluated 15 min or 24 hr after reperfusion. Hepatic IPC attenuated the expression of proinflammatory cytokines, tumor necrosis factor α, intercellular adhesion molecule 1, and induced inducible nitric-oxide synthase, and the phosphorylation of Akt in the murine kidney. Renal function was better preserved in mice with hepatic IPC (group III) than groups II or IV. Hepatic IPC protects against distant renal IR injury through the blood stream-delivery of hepatic IPC-induced ROS, by inducing cytoprotective proteins, and by inhibiting inflammatory reactions.


Subject(s)
Ischemic Preconditioning , Reperfusion Injury/metabolism , Animals , Intercellular Adhesion Molecule-1/genetics , Intercellular Adhesion Molecule-1/metabolism , Kidney/drug effects , Kidney/metabolism , Kidney/pathology , Kidney/physiopathology , Liver/blood supply , Liver/drug effects , Liver/physiopathology , Male , Mice , Mice, Inbred C57BL , Nitric Oxide Synthase Type II/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Reactive Oxygen Species/metabolism , Reperfusion Injury/pathology , Reperfusion Injury/prevention & control , Tiopronin/pharmacology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
18.
Anal Sci ; 27(4): 375, 2011.
Article in English | MEDLINE | ID: mdl-21478612

ABSTRACT

Piezoelectric inkjet printing of polymers and proteins holds great promise for fabrication of miniaturized bioelectronic devices, such as biochips and biosensors. In this study, a bienzymatic glucose biosensor prototype based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS), glucose oxidase (GOD), and horseradish peroxidase (HRP) was fabricated by a piezoelectric inkjet printer. An aqueous bioelectrical ink containing PEDOT-PSS, GOD, and HRP was prepared and printed on an indium-tin-oxide (ITO)-coated poly(ethylene terephthalate) (PET) film. The PEDOT-PSS/GOD/HRP sensor was covered with a cellulose acetate membrane. The use of bienzymatic sensing combined with conducting polymers via piezoelectric inkjet printing showed a synergistic effect resulting in significant amplification of the response signal. The glucose sensor reached steady-state current density within 3 s, indicating a fast response time, and exhibited a linear dose-dependent electrochemical response with high sensitivity. The overall result demonstrates that a glucose sensor with high sensitivity could be readily fabricated by a piezoelectric inkjet printing system.


Subject(s)
Biosensing Techniques/methods , Electric Conductivity , Glucose Dehydrogenases/metabolism , Glucose/analysis , Horseradish Peroxidase/metabolism , Polystyrenes/chemistry , Printing/methods , Thiophenes/chemistry , Electrochemistry , Ink , Tin Compounds/chemistry
19.
Mol Immunol ; 48(11): 1338-43, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21144590

ABSTRACT

Although the etiology of rheumatoid arthritis (RA) remains unknown, it has been widely suggested that RA has a genetic background. In humans, a copy number loss of 22q11.2, a region harboring the VPREB1 gene, has been suggested to be associated with several immunologic disorders, but there has been no study on the copy number variation (CNV) of the VPREB1 and its potential association with RA. Here, we explored the association between the RA and the CNV of the VPREB1 gene by performing genomic quantitative PCR and quantification of B cell subsets in RA patients and controls. The proportion of the individuals with <2 copies of the VPREB1 gene was significantly higher in the patient group than that in the controls (12.9% vs 0.9%, p<0.0001), while that of the individuals with >2 copies was lower in the patient group than that in the controls (1.7% vs 18.9%, p<0.0001). The odds ratio (OR) of the individuals with <2 copies was significantly higher compared with the odds ratio of those individuals with 2 copies (OR=12.1, 95% confidence interval (CI) 2.8-51.6). Likewise, the OR of the individuals with >2 copies was significantly lower than the OR of those individuals with 2 copies (OR=0.09, 95% CI 0.03-0.3). We also found that the proportion of CD21⁻CD23⁻ B cells was significantly higher in the RA patients compared with that of the controls (11.9% vs 5.7%, p=0.002), but the proportion of CD21+CD23+ cells was significantly lower in the RA patients (26.2% in RA vs 34.9% in the controls, p=0.005). To the best of our knowledge, this is the first evidence showing the association between a low copy number of the VPREB1 gene and RA, and this may help understanding the pathogenesis of RA and other autoimmune disorders.


Subject(s)
Arthritis, Rheumatoid/genetics , Gene Dosage , Genetic Predisposition to Disease , Immunoglobulin Light Chains, Surrogate/genetics , Adult , Aged , Arthritis, Rheumatoid/immunology , B-Lymphocytes/immunology , Female , Humans , Immunoglobulin Light Chains, Surrogate/immunology , Male , Middle Aged , Receptors, Complement 3d/genetics , Receptors, Complement 3d/immunology , Receptors, IgE/genetics , Receptors, IgE/immunology
20.
Korean J Anesthesiol ; 59(3): 203-5, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20877706

ABSTRACT

We report a case of Rumpel-Leede (RL) phenomenon, - acute dermis capillary rupture, secondary to noninvasive blood pressure (NIBP) monitoring in a patient with type 2 diabetes mellitus (DM) and hypertension. The first most likely cause is vascular fragility in microangiopathy as a result of DM and chronic steroid use. The second is the increased venous pressure during cycling of the blood pressure cuff in a hypertensive state. Anesthesiologists need to be aware that acute dermal capillary rupture, although rare, can occur in patients with long-standing DM, hypertension and chronic steroid use.

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