Over the last two decades, several tissue clearing methodologies have been established that render tissues optically transparent and allow imaging of unsectioned tissues of significant volumes, thus improving the capacity to study the relationships between cell and 3D tissue architecture. Despite these technical advances, the important unsolved challenges that these methods face include complexity, time, consistency of tissue size before and after clearing, and ability to immunolabel various antibodies in cleared tissue. Here, we established very simple and fast tissue clearing protocol, FxClear, which involves acrylamide-free electrophoretic tissue clearing (ETC). By removal of the acrylamide infusion step, we were able to achieve fast reaction time, smaller tissue expansion, and higher immunoreactivity. Especially, immunoreactivity and fluorescence intensity were increased in FxClear-processed tissues compared to un-cleared tissues. Our protocol may be suitable for small-sized biopsy samples for 3D pathological examinations.
Acrylamide ; Antibodies ; Biopsy ; Fluorescence ; Immunohistochemistry ; Methods ; Reaction Time ; Tissue Engineering ; Tissue Expansion

OBJECTIVETo investigate acrylamide (ACR)-induced subacute neurotoxic effects on the central nervous system (CNS) at the synapse level in rats.

METHODSThirty-six Sprague Dawley (SD) rats were randomized into three groups, (1) a 30 mg/kg ACR-treated group, (2) a 50 mg/kg ACR-treated group, and (3) a normal saline (NS)-treated control group. Body weight and neurological changes were recorded each day. At the end of the test, cerebral cortex and cerebellum tissues were harvested and viewed using light and electron microscopy. Additionally, the expression of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were investigated.

RESULTSThe 50 mg/kg ACR-treated rats showed a significant reduction in body weight compared with untreated individuals (P < 0.05). Rats exposed to ACR showed a significant increase in gait scores compared with the NS control group (P < 0.05). Histological examination indicated neuronal structural damage in the 50 mg/kg ACR treatment group. The active zone distance (AZD) and the nearest neighbor distance (NND) of synaptic vesicles in the cerebral cortex and cerebellum were increased in both the 30 mg/kg and 50 mg/kg ACR treatment groups. The ratio of the distribution of synaptic vesicles in the readily releasable pool (RRP) was decreased. Furthermore, the expression levels of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were decreased in both the 30 mg/kg and 50 mg/kg ACR treatment groups.

CONCLUSIONSubacute ACR exposure contributes to neuropathy in the rat CNS. Functional damage of synaptic proteins and vesicles may be a mechanism of ACR neurotoxicity.

Acrylamide ; toxicity ; Animals ; Cerebellum ; cytology ; drug effects ; Cerebral Cortex ; cytology ; drug effects ; Drug Administration Schedule ; Gait ; Gene Expression Regulation ; drug effects ; Male ; Neurons ; drug effects ; Neurotoxicity Syndromes ; pathology ; Rats ; Rats, Sprague-Dawley ; Synapses ; drug effects ; Synapsins ; genetics ; metabolism ; Synaptic Vesicles ; drug effects ; physiology ; Weight Loss ; drug effects

BACKGROUND: Peripheral neuritis caused by acrylamide is well-known, and many Korean grouting workers are frequently exposed to acrylamide in grouting agents that are injected into cracked concrete. We recently encountered two cases of dermal and neural toxicity in Korean grouting workers with exposure to grouting agents that contained a high concentration of acrylamide. CASE PRESENTATION: The first case involved a 44-year-old man with 8 years of waterproofing experience. The patient developed peeling skin on both hands while grouting, which progressed to systemic neurological symptoms, such as reduced sensory function and strength. The patient was diagnosed with peripheral neuropathy caused by acrylamide exposure, and fully recovered after conservative treatment and withdrawal of exposure to the grouting agent. The second case involved a 34-year-old man with 10 years of grouting experience. The patient initially experienced weakness in both legs, which progressed to weakness in his arms and uncontrolled phonation. After being hospitalized, he was diagnosed with cerebellar ataxia and peripheral neuropathy caused by acrylamide exposure, and was discharged after conservative treatment. Our follow-up investigation revealed that both workers were recently exposed to grouting agents that contained higher concentrations of acrylamide, compared to the agents that they had previously been using. CONCLUSIONS: Both workers had workplace acrylamide exposure through dermal contact plus inhalation of dust and vapor, which led to the neural toxicity and dermatitis. Therefore, government studies are needed to investigate the current status of workplace acrylamide use, and to protect workers from the hazardous effects of using acrylamide-containing grouting agents.
Acrylamide* ; Adult ; Arm ; Cerebellar Ataxia ; Dermatitis ; Dust ; Follow-Up Studies ; Hand ; Humans ; Inhalation ; Korea ; Leg ; Neuritis ; Peripheral Nervous System Diseases ; Phonation ; Sensation ; Skin

The direct interactive effects of rosemary and acrylamide on the development of motor neurons in the spinal cord remains unknown. Our goal is to confirm the protective effects of rosemary against motor neuronal degeneration induced by acrylamide in the developing postnatal rat spinal cord using a postnatal rat model. We assigned the offspring of treated female rats into control, rosemary; acrylamide group; and recovery groups. This work depended on clinical, histopathological, morphometrically, immunohistochemical and genetic methods. In the acrylamide group, we observed oxidation, motor neuron degeneration, apoptosis, myelin degeneration, neurofilament reduction, reactive gliosis. Whoever, concomitant rosemary intake and withdrawal of acrylamide modulate these effects. These findings proof that dietary rosemary can directly protect motor neuron against acrylamide toxicity in the mammalian developing spinal cord.
Acrylamide* ; Animals ; Apoptosis ; Female ; Follow-Up Studies* ; Gliosis ; Humans ; Models, Animal ; Motor Neurons ; Myelin Sheath ; Rats* ; Spinal Cord*

OBJECTIVEThe aim of this study is to investigate hepatic and renal toxicity of acrylamide (ACR) , the antagonistic effect and possible mechanism of N-acetylcysteine (NAC) on the toxicity.

METHODSForty female SD rats were randomly divided into four groups. All the rats were administrated by intraperitoneal(i.p.) injection and 1.5 hours later by gavage. The control group was administrated with 0.9% NaCl by i.p. injection and gavaged with 0.9% NaCl. The NAC group was administrated with 200 mg/kg NAC by injection and gavaged with 0.9% NaCl. The ACR group was administrated with 0.9% NaCl by injection and gavaged with 40 mg/kg ACR. The combined treatment group was administrated with 200 mg/kg NAC by i.p. injection and gavaged with 40 mg/kg ACR. The rats were administrated once a day for 2 weeks. After 24 hours of the last administration, the rats were decapitated. The blood was collected, the liver and kidney were separated. The body weight, organ coefficient and serum biochemical parameters were measured, and the pathological changes of the tissues were examined with a microscope. Then the expression of NF-κB p65, IκB-α and COX-2 were detected by Western blot.

RESULTSFrom the second day to the end of the exposure, the body weight of rats in the ACR group was statistically lower than that in the control group (P<0.05) . Compared with the combined treatment group, the body weight in the ACR group statistically decreased in the second and third days (P < 0.05) . The liver and kidney organ coefficients in the ACR group were (4.159%±.371%) and (0.764%±0.068%) respectively, which increased statistically when compared with the control group (P < 0.05) . The contents of ALT, AST and Cr in the serum in the ACR group were (77.370±16.397) U/L、(379.410±57.817) U/L and (77.812±6.391) μmol/L respectively, which were not significantly different with those in the control group and the combined treatment group (P>0.05) . The content of BUN in the serum in the ACR group was (7.005±1.009) mmol/L, which was statistically higher than that in the control group (P<0.05) . Histopathology results showed unclear boundary and nucleus pyknosis in hepatocytes, loose and disordered structures of hepatic cords in the ACR group, but no obvious pathology changes were observed in the kidneys of each group. In the Western blot results, the expression of nuclear NF-κB p65 and COX-2 in the liver in the ACR group was statistically higher than that in the control group and the combined treatment group (P<0.05) , and the expression of IκB-α in the liver in the ACR group statistically decreased compared with the control group and the combined treatment group (P<0.05) . The expression of total NF-κB p65 in the liver in the ACR group was statistically higher than that in the control group (P<0.05) .

CONCLUSIONUnder the conditions of this experiment, ACR may induce hepatic toxicity through the activation of NF-κB signaling pathway, and NAC could antagonize the hepatic toxicity of ACR by inhibiting the NF-κB signaling pathway, whereas the toxic effect of ACR on kidney needs to be further studied.

Acetylcysteine ; pharmacology ; Acrylamide ; toxicity ; Animals ; Cyclooxygenase 2 ; metabolism ; Female ; I-kappa B Proteins ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Liver ; drug effects ; metabolism ; NF-KappaB Inhibitor alpha ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Transcription Factor RelA ; metabolism

The purpose of this study was to study the role of neurofilament (NF) mRNA and calpain in NF reduction of acrylamide (ACR) neuropathy. Male Wistar adult rats were injected i.p. every other day with ACR (20 mg/kg·bW or 40 mg/kg·bW) for 8 weeks. NF mRNA expression was detected using RT-PCR and the calpain concentration was determined using western blot analysis. The NF mRNA expression significantly decreased while the level of m-calpain and μ-calpain significantly increased in two ACR-treated rats groups regardless of the ACR dose. The light NF (NF-L) protein expression was significantly correlated with NF-L mRNA expression. Combined with previous data, the concentrations of three NF subunits were negatively correlated with the calpain levels. These findings suggest that NF-L mRNA and calpain mediated the reduction in NF of ACR neuropathy.
Acrylamide ; toxicity ; Animals ; Calpain ; metabolism ; Gene Expression Regulation ; drug effects ; Intermediate Filaments ; genetics ; Male ; Peripheral Nervous System Diseases ; chemically induced ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats

OBJECTIVETo investigate the immunotoxicity of acrylamide (ACR) in female BALB/c mice.

METHODSA total of 200 female mice weighing 18-22 g were randomly divided into four clusters based on body weight, and each weight-based cluster included five groups (10 mice per group): negative control, positive control (cyclophosphamide), low, intermediate, and high dose ACR groups, and all the groups were administered ACR by gavage for 30 days. At the end of the study, the immunotoxicological effects of the ACR were evaluated through immunopathology, humoral immunity, cellular immunity, and non-specific immunity.

RESULTSThe terminal body weight, spleen and thymus weights, lymphocyte counts in the ACR-H group were decreased, pathological changes were observed in lymph glands, thymus and spleen. %T cells in blood lymphocytes were significantly increased in all ACR-treated groups, and a significant reduction of % natural killer(NK) cells and increase of %Th cells were observed in the ACR-H group. interleukin-6(IL-6), Concanavalin A(ConA)-induced splenocyte proliferation and serum half hemolysis value (HC50) were also significantly suppressed in the ACR-H group.

CONCLUSIONACR elicited an inhibitory effect on cellular and humoral immunity of mice after 30 day feeding.

Acrylamide ; toxicity ; Animals ; Body Weight ; drug effects ; CD4-CD8 Ratio ; Cytokines ; blood ; Female ; Immunity, Cellular ; drug effects ; Immunity, Humoral ; drug effects ; Immunophenotyping ; Immunotoxins ; toxicity ; Mice ; Mice, Inbred BALB C ; Organ Size ; drug effects ; Random Allocation ; Spleen ; drug effects ; Thymus Gland ; drug effects ; Toxicity Tests

PURPOSE: Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism. MATERIALS AND METHODS: Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature (Tg) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01). RESULTS: The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly. CONCLUSION: Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins.
Acrylamide ; Acrylic Resins ; Chicago ; Collodion ; Denture Bases ; Dentures ; Diamond ; Glass ; Hardness ; Hardness Tests ; Polymethyl Methacrylate ; Pyridines ; Spectroscopy, Fourier Transform Infrared ; Spectrum Analysis ; Thiazoles ; Transition Temperature

Acrylamide ; toxicity ; Animals ; Behavior, Animal ; drug effects ; Blotting, Western ; Cytoskeletal Proteins ; blood ; Dose-Response Relationship, Drug ; Electrophoresis, Polyacrylamide Gel ; Gait Ataxia ; blood ; chemically induced ; Male ; Motor Activity ; drug effects ; Neurotoxicity Syndromes ; blood ; etiology ; Rats ; Rats, Wistar

The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n=10) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer's instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5% (-5), 10% (-10), 15% (-15) and 20% (-20) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal-Wallis test (α=0.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 °C⋅min(-1) from 35 °C to 600 °C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (P<0.01). Ac-10 and Ac-15 showed significance when compared to Ac-c (P<0.01). Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c (P<0.01). Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c (P<0.01). According to the (1)H-nuclear magnetic resonance (NMR) results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm.
Acrylamide ; chemistry ; Acrylic Resins ; chemistry ; Dental Materials ; chemistry ; Denture Bases ; Elastic Modulus ; Hot Temperature ; Humans ; Magnetic Resonance Spectroscopy ; Materials Testing ; Microwaves ; Pliability ; Polymerization ; Polymethyl Methacrylate ; chemistry ; Powders ; Solutions ; Stress, Mechanical ; Thermodynamics ; Thermogravimetry ; Time Factors