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Vasorelaxation effect of Glycyrrhizae uralensis through the endothelium-dependent Pathway

Tan CS, Ch'ng YS, Loh YC, Zaini Asmawi M, Ahmad M, Yam MF

J Ethnopharmacol, 2017 Mar 06;199:149-160.
PMID: 28161542 DOI: 10.1016/j.jep.2017.02.001

ETHNOPHARMACOLOGICAL RELEVANCE: Glycyrrhiza uralensis (G. uralensis) is one of the herbs used in traditional Chinese medicine (TCM) and serves as an envoy medicinal. Since G. uralensis plays a major role in the anti-hypertensive TCM formulae, we believe that G. uralensis might possess vasorelaxation activity.
AIM OF THE STUDY: This study is designed to investigate the vasorelaxation effect of G. uralensis from various extracts and to study its pharmacology effect.
MATERIALS AND METHODS: The vasorelaxation effect of G. uralensis extracts were evaluated on thoracic aortic rings isolated from Sprague Dawley rats.
RESULTS: Among these three extracts of G. uralensis, 50% ethanolic extract (EFG) showed the strongest vasorelaxation activity. EFG caused the relaxation of the aortic rings pre-contracted with phenylephrine either in the presence or absence of endothelium and pre-contracted with potassium chloride in endothelium-intact aortic ring. Nω-nitro-L-arginine methyl ester, methylene blue, or 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one inhibit the vasorelaxation effect of EFG in the presence of endothelium. On the other hand, in the presence of the potassium channel blockers (tetraethylammonium and barium chloride), the vasorelaxation effect of EFG was not affected, but glibenclamide and 4-aminopyridine did inhibit the vasorelaxation effect of EFG. With indomethacin, atropine and propranolol, the vasorelaxation effect by EFG was significantly reduced. EFG was also found to be effective in reducing Ca(2+) release from sarcoplasmic reticulum and the blocking of calcium channels.
CONCLUSIONS: The results obtained suggest that EFG is involved in the NO/sGC/cGMP pathway.

Matched MeSH terms: Organ Culture Techniques
Fulltext Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism

Ch'ng YS, Loh YC, Tan CS, Ahmad M, Asmawi MZ, Wan Omar WM, et al.

Pharm Biol, 2017 Dec;55(1):2083-2094.
PMID: 28832263 DOI: 10.1080/13880209.2017.1357735

CONTEXT: Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia.
OBJECTIVE: This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint.
MATERIALS AND METHODS: Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01-2.55 mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists.
RESULTS: The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC50 of 0.057 ± 0.006 and 0.430 ± 0.196 mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC50 0.971 ± 0.459 mg/mL), methylene blue (EC50 1.203 ± 0.426 mg/mL), indomethacin (EC50 2.128 ± 1.218 mg/mL), atropine (EC50 0.470 ± 0.325 mg/mL), and propranolol (EC50 0.314 ± 0.032 mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC50 0.548 ± 0.184, 0.158 ± 0.012, 0.847 ± 0.342, and 0.304 ± 0.075 mg/mL, respectively). VAE was also found to be active in reducing Ca2+ released from the sarcoplasmic reticulum and blocking calcium channels.
CONCLUSIONS: The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI2 signalling pathways, and modulation of calcium/potassium channels, and muscarinic and β2-adrenergic receptor levels.

Matched MeSH terms: Organ Culture Techniques
Treatment with salvianolic acid B restores endothelial function in angiotensin II-induced hypertensive mice

Ling WC, Liu J, Lau CW, Murugan DD, Mustafa MR, Huang Y

Biochem Pharmacol, 2017 Jul 15;136:76-85.
PMID: 28396195 DOI: 10.1016/j.bcp.2017.04.007

Salvianolic acid B (Sal B) is one of the most abundant phenolic acids derived from the root of Danshen with potent anti-oxidative properties. The present study examined the vasoprotective effect of Sal B in hypertensive mice induced by angiotensin II (Ang II). Sal B (25mg/kg/day) was administered via oral gavage for 11days to Ang II (1.2mg/kg/day)-infused C57BL/6J mice (8-10weeks old). The vascular reactivity (both endothelium-dependent relaxations and contractions) in mouse arteries was examined by wire myography. The production of reactive oxygen species (ROS), protein level and localization of angiotensin AT1 receptors and the proteins involved in ROS formation were evaluated using dihydroethidium (DHE) fluorescence, lucigenin-enhanced chemiluminescence, immunohistochemistry and Western blotting, respectively. The changes of ROS generating proteins were also assessed in vitro in human umbilical vein endothelial cells (HUVECs) exposed to Ang II with and without co-treatment with Sal B (0.1-10nM). Oral administration of Sal B reversed the Ang II-induced elevation of arterial systolic blood pressure in mice, augmented the impaired endothelium-dependent relaxations and attenuated the exaggerated endothelium-dependent contractions in both aortas and renal arteries of Ang II-infused mice. In addition, Sal B treatment normalized the elevated levels of AT1 receptors, NADPH oxidase subunits (NOx-2 and NOx-4) and nitrotyrosine in arteries of Ang II-infused mice or in Ang II-treated HUVECs. In summary, the present study provided additional evidence demonstrating that Sal B treatment for 11days reverses the impaired endothelial function and with a marked inhibition of AT1 receptor-dependent vascular oxidative stress. This vasoprotective and anti-oxidative action of Sal B most likely contributes to the anti-hypertensive action of the plant-derived compound.

Matched MeSH terms: Organ Culture Techniques
Transdermal anti-inflammatory activity of bilayer film containing olive compound hydroxytyrosol: physical assessment, in vivo dermal safety and efficacy study in Freund's adjuvant-induced arthritic rat model

Ng SF, Tan LS, Buang F

Drug Dev Ind Pharm, 2017 Jan;43(1):108-119.
PMID: 27588411 DOI: 10.1080/03639045.2016.1224893

Previous studies have shown that hydroxytyrosol (HT) can be a potential alternative therapeutic agent for the treatment of rheumatoid arthritis (RA). However, HT is extensively metabolized following oral administration, which leads to formulating HT in a topical vehicle to prolong drug action as well as to provide a localized effect. Hidrox-6 is a freeze-dried powder derived from fresh olives and contains a high amount of HT (∼3%) and other polyphenols. Alginate bilayer films containing 5% and 10% Hidrox-6 were formulated. The films were characterized with respect to their physical, morphology, rheological properties; drug content uniformity; and in vitro drug release. Acute dermal irritancy tests and a skin sensitization study were carried out in rats. An efficacy study of the bilayer films for RA was conducted using Freund's adjuvant-induced polyarthritis rats. Animal data showed that the bilayer film formulations did not cause skin irritancy. The efficacy in vivo results showed that the Hidrox-6 bilayer films lowered the arthritic scores, paw and ankle circumference, serum IL-6 level and cumulative histological scores compared with those measured for controls. The topical Hidrox-6 bilayer films improve synovitis and inflammatory symptoms in RA and can be a potential alternative to oral RA therapy.

Matched MeSH terms: Organ Culture Techniques
Fulltext Transcription factor CREB3L1 regulates vasopressin gene expression in the rat hypothalamus

Greenwood M, Bordieri L, Greenwood MP, Rosso Melo M, Colombari DS, Colombari E, et al.

J Neurosci, 2014 Mar 12;34(11):3810-20.
PMID: 24623760 DOI: 10.1523/JNEUROSCI.4343-13.2014

Arginine vasopressin (AVP) is a neurohypophysial hormone regulating hydromineral homeostasis. Here we show that the mRNA encoding cAMP responsive element-binding protein-3 like-1 (CREB3L1), a transcription factor of the CREB/activating transcription factor (ATF) family, increases in expression in parallel with AVP expression in supraoptic nuclei (SONs) and paraventicular nuclei (PVNs) of dehydrated (DH) and salt-loaded (SL) rats, compared with euhydrated (EH) controls. In EH animals, CREB3L1 protein is expressed in glial cells, but only at a low level in SON and PVN neurons, whereas robust upregulation in AVP neurons accompanied DH and SL rats. Concomitantly, CREB3L1 is activated by cleavage, with the N-terminal domain translocating from the Golgi, via the cytosol, to the nucleus. We also show that CREB3L1 mRNA levels correlate with AVP transcription level in SONs and PVNs following sodium depletion, and as a consequence of diurnal rhythm in the suprachiasmatic nucleus. We tested the hypothesis that CREB3L1 activates AVP gene transcription. Both full-length and constitutively active forms of CREB3L1 (CREB3L1CA) induce the expression of rat AVP promoter-luciferase reporter constructs, whereas a dominant-negative mutant reduces expression. Rat AVP promoter deletion constructs revealed that CRE-like and G-box sequences in the region between -170 and -120 bp are important for CREB3L1 actions. Direct binding of CREB3L1 to the AVP promoter was shown by chromatin immunoprecipitation both in vitro and in the SON itself. Injection of a lentiviral vector expressing CREB3L1CA into rat SONs and PVNs resulted in increased AVP biosynthesis. We thus identify CREB3L1 as a regulator of AVP transcription in the rat hypothalamus.

Matched MeSH terms: Organ Culture Techniques
Fulltext Transcription factor CREB3L1 mediates cAMP and glucocorticoid regulation of arginine vasopressin gene transcription in the rat hypothalamus

Greenwood M, Greenwood MP, Mecawi AS, Loh SY, Rodrigues JA, Paton JF, et al.

Mol Brain, 2015 Oct 26;8(1):68.
PMID: 26503226 DOI: 10.1186/s13041-015-0159-1

BACKGROUND: Arginine vasopressin (AVP), a neuropeptide hormone that functions in the regulation of water homeostasis by controlling water re-absorption at kidneys, is synthesised in supraoptic nucleus and paraventricular nucleus of the hypothalamus. An increase in plasma osmolality stimulates secretion of AVP to blood circulation and induces AVP synthesis in these nuclei. Although studies on mechanism of AVP transcriptional regulation in hypothalamus proposed that cAMP and glucocorticoids positively and negatively regulate Avp expression, respectively, the molecular mechanisms have remained elusive. Recently, we identified CREB3L1 (cAMP-responsive element binding protein 3 like 1) as a putative transcription factor of Avp transcription in the rat hypothalamus. However the mechanism of how CREB3L1 is regulated in response of hyperosmotic stress in the neurons of hypothalamus has never been reported. This study aims to investigate effect of previously reported regulators (cAMP and glucocorticoid) of Avp transcription on transcription factor CREB3L1 in order to establish a molecular explanation for cAMP and glucocorticoids effect on AVP expression.
RESULTS: The effect of cAMP and glucocorticoid treatment on Creb3l1 was investigated in both AtT20 cells and hypothalamic organotypic cultures. The expression of Creb3l1 was increased in both mRNA and protein level by treatment with forskolin, which raises intracellular cAMP levels. Activation of cAMP by forskolin also increased Avp promoter activity in AtT20 cells and this effect was blunted by shRNA mediated silencing of Creb3l1. The forskolin induced increase in Creb3l1 expression was diminished by combined treatment with dexamethasone, and, in vivo, intraperitoneal dexamethasone injection blunted the increase in Creb3l1 and Avp expression induced by hyperosmotic stress.
CONCLUSION: Here we shows that cAMP and glucocorticoid positively and negatively regulate Creb3l1 expression in the rat hypothalamus, respectively, and regulation of cAMP on AVP expression is mediated through CREB3L1. This data provides the connection between CREB3L1, a newly identified transcription factor of AVP expression, with the previously proposed mechanism of Avp transcription which extends our understanding in transcription regulation of Avp in the hypothalamus.

Matched MeSH terms: Organ Culture Techniques
Towards engineering of a tracheal equivalent: identification of epithelial precursor cells, differentiation and cocultivation techniques

Rotter N, Stölzel K, Endres M, Leinhase I, Ziegelaar BW, Sittinger M

Med J Malaysia, 2004 May;59 Suppl B:35-6.
PMID: 15468806
Matched MeSH terms: Organ Culture Techniques
Tissue-engineered bone via seeding bone marrow stem cell derived osteoblasts into coral: a rat model

Al-Salihi KA

Med J Malaysia, 2004 May;59 Suppl B:200-1.
PMID: 15468887

In the present study, natural coral of porites species was used as scaffold combined with in vitro expanded bone marrow stem cell derived osteoblasts (BMSC-DO), to develop a tissue-engineered bone graft in a rat model. Coral was molded into the shape of rat mandible seeded with 5x10(6) /ml BMSC-DO subsequently implanted subcutaneously in the back of 5 week Sprague dawely rats for 3 months. Coral alone was implanted as a control. The implants were harvest and processed for gross inspection and histological observations. The results showed that newly bone grafts were successfully formed coral seeded with cells group showed smooth highly vascularized like bone tissue. Histological sections revealed mature bone formation and lots of blood vessel, the bone formation occurred in the manner resemble intramembraneous bone formation. This study demonstrates that coral can be use as a suitable scaffold material for delivering bone marrow mesenchymal stem cells in tissue engineering.

Matched MeSH terms: Organ Culture Techniques/methods*
Tissue engineered trachea using sheep nasal septum

Kojima K

Med J Malaysia, 2004 May;59 Suppl B:32-3.
PMID: 15468805
Matched MeSH terms: Organ Culture Techniques
The fundamentals of tissue engineering: new scaffolds

Di Silvio L, Gurav N, Sambrook R

Med J Malaysia, 2004 May;59 Suppl B:89-90.
PMID: 15468832

The ability to regenerate new bone for skeletal use is a major clinical need. In this study, two novel porous calcium phosphate materials pure HA and biphasic HA/beta-Tricalcium phosphate (HA/beta -TCP) were evaluated as potential scaffolds for cell-seeded bone substitutes using human osteoblast-like cells (HOS) and primary human mesenchymal stem cells (hMSCs). A high rate of proliferation was observed on both scaffolds. A greater increase in alkaline phosphatase (ALP- an indicator of osteoblast differentiation) was observed on HA/beta -TCP compared to HA. This observation indicates that HA/TCP may play a role in inducing osteoblastic differentiation. Although further evaluation is required both materials show potential as innovative synthetic substitutes for tissue engineered scaffolds.

Matched MeSH terms: Organ Culture Techniques/standards*
Strategy for generating tissue-engineered human bone construct

Tan KK, Aminuddin BS, Tan GH, Sabarul Afian M, Ng MH, Fauziah O, et al.

Med J Malaysia, 2004 May;59 Suppl B:43-4.
PMID: 15468810

The strategy used to generate tissue-engineered bone construct, in view of future clinical application is presented here. Osteoprogenitor cells from periosteum of consenting scoliosis patients were isolated. Growth factors viz TGF-B2, bFGF and IGF-1 were used in concert to increase cell proliferation during in vitro cell expansion. Porous tricalcium phosphate (TCP)-hydroxyapatite (HA) scaffold was used as the scaffold to form 3D bone construct. We found that the addition of growth factors, greatly increased cell growth by 2 to 7 fold. TCP/HA proved to be the ideal scaffold for cell attachment and proliferation. Hence, this model will be further carried out on animal trial.

Matched MeSH terms: Organ Culture Techniques
Fulltext Squamous epitheliotropism of Enterovirus A71 in human epidermis and oral mucosa

Phyu WK, Ong KC, Kong CK, Alizan AK, Ramanujam TM, Wong KT

Sci Rep, 2017 03 21;7:45069.
PMID: 28322333 DOI: 10.1038/srep45069

Hand-foot-and-mouth disease is a self-limiting paediatric infectious disease commonly caused by Enterovirus A71 (Genus: Enterovirus, Family: Picornaviridae). Typical lesions in and around the hands, feet, oral cavity and other places may rarely be complicated by acute flaccid paralysis and acute encephalomyelitis. Although virus is readily cultured from skin vesicles and oral secretions, the cellular target/s of Enterovirus A71 in human skin and oral mucosa are unknown. In Enterovirus A71-infected human skin and oral mucosa organotypic cultures derived from the prepuce and lip biopsies, focal viral antigens and viral RNA were localized to cytoplasm of epidermal and mucosal squamous cells as early as 2 days post-infection. Viral antigens/RNA were associated with cytoplasmic vacuolation and cellular necrosis. Infected primary prepuce epidermal keratinocyte cultures showed cytopathic effects with concomitant detection of viral antigens from 2 days post-infection. Supernatant and/or tissue homogenates from prepuce skin organotypic cultures and primary prepuce keratinocyte cultures showed viral titres consistent with active viral replication. Our data strongly support Enterovirus A71 squamous epitheliotropism in the human epidermis and oral mucosa, and suggest that these organs are important primary and/or secondary viral replication sites that contribute significantly to oral and cutaneous viral shedding resulting in person-to-person transmission, and viraemia, which could lead to neuroinvasion.

Matched MeSH terms: Organ Culture Techniques
Size-related assessment on viability and insulin secretion of caprine islets in vitro

Vakhshiteh F, Allaudin ZN, Mohd Lila MA, Hani H

Xenotransplantation, 2013 02 14;20(2):82-8.
PMID: 23406308 DOI: 10.1111/xen.12023

BACKGROUND: The successful isolation, purification, and culture of caprine islets has recently been reported. The present study shows arange of size distribution in caprine islet diameter from 50 to 250 μm, in which 80% of the total islet yield was comprised of small islets.
METHODS: Caprine islets were isolated and purified. Islets were handpicked and the diameter of the islets was recorded using light microscopy. Viablility of the islets was analyzed by confocal microscopy. Insulin secretion assay was carried out and analyzed by ELISA.
RESULTS: When tested at 48 h after isolation, these small islets were 29.3% more viable compared to the large-sized islets. Large islets showed a high ratio (P

Matched MeSH terms: Organ Culture Techniques
Scaffolds in bone tissue engineering

Nather A

Med J Malaysia, 2004 May;59 Suppl B:37-8.
PMID: 15468807
Matched MeSH terms: Organ Culture Techniques/methods*
Quercetin, a flavonoid antioxidant, modulates endothelium-derived nitric oxide bioavailability in diabetic rat aortas

Machha A, Achike FI, Mustafa AM, Mustafa MR

Nitric Oxide, 2007 Jun;16(4):442-7.
PMID: 17513143 DOI: 10.1016/j.niox.2007.04.001

The present work examined the effect of chronic oral administration of quercetin, a flavonoid antioxidant, on blood glucose, vascular function and oxidative stress in STZ-induced diabetic rats. Male Wistar-Kyoto (WKY) rats were randomized into euglycemic, untreated diabetic, vehicle (1% w/v methylcellulose)-treated diabetic, which served as control, or quercetin (10mgkg(-1) body weight)-treated diabetic groups and treated orally for 6 weeks. Quercetin treatment reduced blood glucose level in diabetic rats. Impaired relaxations to endothelium-dependent vasodilator acetylcholine (ACh) and enhanced vasoconstriction responses to alpha(1)-adrenoceptor agonist phenylephrine (PE) in diabetic rat aortic rings were restored to euglycemic levels by quercetin treatment. Pretreatment with N(omega)-nitro-l-arginine methyl ester (l-NAME, 10microM) or methylene blue (10microM) completely blocked but indomethacin (10microM) did not affect relaxations to ACh in aortic rings from vehicle- or quercetin-treated diabetic rats. PE-induced vasoconstriction with an essentially similar magnitude in vehicle- or quercetin-treated diabetic rat aortic rings pretreated with l-NAME (10microM) plus indomethacin (10microM). Quercetin treatment reduced plasma malonaldehyde (MDA) plus 4-hydroxyalkenals (4-HNE) content as well as increased superoxide dismutase activity and total antioxidant capacity in diabetic rats. From the present study, it can be concluded that quercetin administration to diabetic rats restores vascular function, probably through enhancement in the bioavailability of endothelium-derived nitric oxide coupled to reduced blood glucose level and oxidative stress.

Matched MeSH terms: Organ Culture Techniques
Preparation and characterization of dutasteride-loaded nanostructured lipid carriers coated with stearic acid-chitosan oligomer for topical delivery

Noor NM, Sheikh K, Somavarapu S, Taylor KMG

Eur J Pharm Biopharm, 2017 Aug;117:372-384.
PMID: 28412472 DOI: 10.1016/j.ejpb.2017.04.012

Dutasteride, used for treating benign prostate hyperplasia (BPH), promotes hair growth. To enhance delivery to the hair follicles and reduce systemic effects, in this study dutasteride has been formulated for topical application, in a nanostructured lipid carrier (NLC) coated with chitosan oligomer-stearic acid (CSO-SA). CSO-SA has been successfully synthesized, as confirmed using1H NMR and FTIR. Formulation of dutasteride-loaded nanostructured lipid carriers (DST-NLCs) was optimized using a 23full factorial design. This formulation was coated with different concentrations of stearic acid-chitosan solution. Coating DST-NLCs with 5% SA-CSO increased mean size from 187.6±7.0nm to 220.1±11.9nm, and modified surface charge, with zeta potentials being -18.3±0.9mV and +25.8±1.1mV for uncoated and coated DST-NLCs respectively. Transmission electron microscopy showed all formulations comprised approximately spherical particles. DST-NLCs, coated and uncoated with CSO-SA, exhibited particle size stability over 60days, when stored at 4-8°C. However, NLCs coated with CSO (without conjugation) showed aggregation when stored at 4-8°C after 30days. The measured particle size for all formulations stored at 25°C suggested aggregation, which was greatest for DST-NLCs coated with 10% CSO-SA and 5% CSO. All nanoparticle formulations exhibited rapid release in an in vitro release study, with uncoated NLCs exhibiting the fastest release rate. Using a Franz diffusion cell, no dutasteride permeated through pig ear skin after 48h, such that it was not detected in the receptor chamber for all samples. The amount of dutasteride in the skin was significantly different (p<0.05) for DST-NLCs (6.09±1.09μg/cm2) without coating and those coated with 5% CSO-SA (2.82±0.40μg/cm2), 10% CSO-SA (2.70±0.35μg/cm2) and CSO (2.11±0.64μg/cm2). There was a significant difference (p<0.05) in the cytotoxicity (IC50) between dutasteride alone and in the nanoparticles. DST-NLCs coated and uncoated with CSO-SA increased the maximum non-toxic concentration by 20-fold compared to dutasteride alone. These studies indicate that a stearic acid-chitosan conjugate was successfully prepared, and modified the surface charge of DST-NLCs from negative to positive. These stable, less cytotoxic, positively-charged dutasteride-loaded nanostructured lipid carriers, with stearic acid-chitosan oligomer conjugate, are appropriate for topical delivery and have potential for promotion of hair growth.

Matched MeSH terms: Organ Culture Techniques
Fulltext Organotypic slice culture based on in ovo electroporation for chicken embryonic central nervous system

Yang C, Li X, Li S, Chai X, Guan L, Qiao L, et al.

J Cell Mol Med, 2019 03;23(3):1813-1826.
PMID: 30565384 DOI: 10.1111/jcmm.14080

Organotypic slice culture is a living cell research technique which blends features of both in vivo and in vitro techniques. While organotypic brain slice culture techniques have been well established in rodents, there are few reports on the study of organotypic slice culture, especially of the central nervous system (CNS), in chicken embryos. We established a combined in ovo electroporation and organotypic slice culture method to study exogenous genes functions in the CNS during chicken embryo development. We performed in ovo electroporation in the spinal cord or optic tectum prior to slice culture. When embryonic development reached a specific stage, green fluorescent protein (GFP)-positive embryos were selected and fluorescent expression sites were cut under stereo fluorescence microscopy. Selected tissues were embedded in 4% agar. Tissues were sectioned on a vibratory microtome and 300 μm thick sections were mounted on a membrane of millicell cell culture insert. The insert was placed in a 30-mm culture dish and 1 ml of slice culture media was added. We show that during serum-free medium culture, the slice loses its original structure and propensity to be strictly regulated, which are the characteristics of the CNS. However, after adding serum, the histological structure of cultured-tissue slices was able to be well maintained and neuronal axons were significantly longer than that those of serum-free medium cultured-tissue slices. As the structure of a complete single neuron can be observed from a slice culture, this is a suitable way of studying single neuronal dynamics. As such, we present an effective method to study axon formation and migration of single neurons in vitro.

Matched MeSH terms: Organ Culture Techniques/methods*
Organotypic culture of human amnion cells in air-liquid interface as a potential substitute for skin regeneration

Fatimah SS, Chua K, Tan GC, Azmi TI, Tan AE, Abdul Rahman H

Cytotherapy, 2013 Aug;15(8):1030-41.
PMID: 23830235 DOI: 10.1016/j.jcyt.2013.05.003

The aim of the present study was to evaluate the effects of air-liquid interface on the differentiation potential of human amnion epithelial cells (HAECs) to skin-like substitute in organotypic culture.

Matched MeSH terms: Organ Culture Techniques
Isolation and characterization of α-elapitoxin-Bf1b, a postsynaptic neurotoxin from Malaysian Bungarus fasciatus venom

Rusmili MR, Tee TY, Mustafa MR, Othman I, Hodgson WC

Biochem Pharmacol, 2014 Mar 15;88(2):229-36.
PMID: 24440452 DOI: 10.1016/j.bcp.2014.01.004

Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus results in neurotoxicity due to the presence of presynaptic and postsynaptic neurotoxins. Antivenom, either monovalent or polyvalent, is the treatment of choice in systemically envenomed patients. In this study, we have isolated a postsynaptic neurotoxin which we named α-elapitoxin-Bf1b. This toxin has an approximate molecular weight of 6.9 kDa, with LCMS/MS data showing that it is highly homologous with Neurotoxin 3FTx-RI, a toxin identified in the Bungarus fasciatus venom gland transcriptome. α-Elapitoxin-Bf1b also shared similarity with short-chain neurotoxins from Laticauda colubrina and Pseudechis australis. α-Elapitoxin-Bf1b produced concentration- and time-dependent neurotoxicity in the indirectly-stimulated chick biventer cervicis muscle preparation, an effect partially reversible by repetitive washing of the preparation. The pA2 value for α-elapitoxin-Bf1b of 9.17 ± 0.64, determined by examining the effects of the toxin on cumulative carbacol concentration-response curves, indicated that the toxin is more potent than tubocurarine and α-bungarotoxin. Pre-incubation of Bungarus fasciatus monovalent and neuro polyvalent antivenom failed to prevent the neurotoxic effects of α-elapitoxin-Bf1b in the chick biventer cervicis muscle preparation. In conclusion, the isolation of a postsynaptic neurotoxin that cannot be neutralized by either monovalent and polyvalent antivenoms may indicate the presence of isoforms of postsynaptic neurotoxins in Malaysian B. fasciatus venom.

Matched MeSH terms: Organ Culture Techniques
Fluorescent cell tracer dye permits real-time assessment of re-epithelialization in a serum-free ex vivo human skin wound assay

Nasir NAM, Paus R, Ansell DM

Wound Repair Regen, 2019 01;27(1):126-133.
PMID: 30575205 DOI: 10.1111/wrr.12688

Ex vivo wounded human skin organ culture is an invaluable tool for translationally relevant preclinical wound healing research. However, studies incorporating this system are still underutilized within the field because of the low throughput of histological analysis required for downstream assessment. In this study, we use intravital fluorescent dye to lineage trace epidermal cells, demonstrating that wound re-epithelialization of human ex vivo wounds occurs consistent with an extending shield mechanism of collective migration. Moreover, we also report a relatively simple method to investigate global epithelial closure of explants in culture using daily fluorescent dye treatment and en face imaging. This study is the first to quantify healing of ex vivo wounds in a longitudinal manner, providing global assessments for re-epithelialization and tissue contraction. We show that this approach can identify alterations to healing with a known healing promoter. This methodological study highlights the utility of human ex vivo wounds in enhancing our understanding of mechanisms of human skin repair and in evaluating novel therapies to improve healing outcome.

Matched MeSH terms: Organ Culture Techniques

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