Analysis of the Cicatricial Acceleration Method (MAC®) in Skin Repair in Wistar Rattus norvegicus with Induced Chemical Burns

Introduction: The cicatricial acceleration method (MAC®) promotes photobiological effects of an anti-inflammatory and healing nature. Its therapeutic radiation is emitted, producing photobiostimulant effects that result in rapid tissue repair and better tissue quality. The treatment of burns has always been a challenge, which involves both performing surgery and controlling and guiding scar regeneration, avoiding possible morbidities. Objective: To evaluate the effects of applying the MAC methodology with an AlGa (aluminum, gallium arsenide) laser on the time and quality of tissue repair in the skin of rats after induced chemical burns. Method: 22 adult male rats were subjected to a second-degree chemical burn on the back using 50% trichloroacetic acid. After the burns, the animals were randomly separated into 2 groups: control and experimental. The control group (G1) received placebo laser therapy and the laser group (G2) underwent laser irradiation with an energy density of 100 J/cm2. Histological analysis and macroscopic evaluation were carried out by means of the paper template method. Results: Group G1 showed (53%) of the necrosis area and group G2 showed (11%) necrosis area. Conclusion: The cicatricial acceleration method (MAC®) favored the repair of wounds caused by a 2nd-degree chemical burn, optimizing time and improving quality.

A Rational Design of Metal–Organic Framework Nanozyme with High‑Performance Copper Active Centers for Alleviating Chemical Corneal Burns

Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.

Evaluation of chronic ocular sequelae in patients with symblepharon caused by ocular burns

AIM:To evaluate chronic ocular sequelae in patients with symblepharon caused by ocular burns and propose an objective grading system.METHODS:This was a retrospective,single-center clinical study.Patients with symblepharon caused by ocular burns at least six months later were assessed.Chronic ocular sequelae were classified into 3 categories(eyelid,conjunctiva,and cornea)and 9 chronic ocular sequelae[friction factors,exposure factors,conjunctival hyperemia,length of symblepharon,scope of adhesion,lacrimal area adhesion,loss of the palisades of Vogt(POV),corneal neovascularization,and corneal opacification].Each ocular sequela was graded from 0 to 3,depending on the increasing severity.The 9 ocular sequelae were evaluated to obtain the total severity score for each eye.The total severity score was defined as Grade I(1-9),Grade II(10-18),and Grade III(19-27).Moreover,the correlation between the severity of chronic ocular sequelae and visual acuity,surgical strategy,and the prognosis was analyzed,respectively.RESULTS:Cases of 79 eyes with symblepharon caused by ocular burns were included in this study.Of these,20(25.32%)were defined as Grade I,43(54.43%)as Grade II,and 16(20.25%)as Grade III.Eyes with a high total severity score had reduced visual acuity,required complicated surger y strategies,and poor prognosis(P<0.001).Multivariate regression analysis showed that the scope of adhesion,corneal opacification,and corneal neovascularization significantly affected visual acuity,surgical strategy,and prognosis(all P<0.001).CONCLUSION:The evaluation of chronic ocular sequelae enabled the development of an objective grading system for patients with symblepharon caused by ocular burns.This grading system can be applied to guide the treatment and predict the prognosis.

Epidemiology and etiology of chemical ocular injury:A brief review

Chemical ocular injury is one of the common ophthalmologic emergencies that can cause vision loss and serious complications.Despite all protective measures,it continues to be a serious public health problem,especially in young male patients.Although it is known that injuries occur most frequently in the workplace and in young male patients,there is a variable frequency and distribution in different regions around the world.In addition,with the coronavirus disease 2019 pandemic,there are changing trends in ocular chemical injuries.This review aims to specify an update on the epidemiological and etiological features of ocular chemical injuries.

Application of transient burning rate model of solid propellant in electrothermal-chemical launch simulation

A 30 mm electrothermal-chemical(ETC) gun experimental system is employed to research the burning rate characteristics of 4/7 high-nitrogen solid propellant. Enhanced gas generation rates(EGGR) of propellants during and after electrical discharges are verified in the experiments. A modified 0D internal ballistic model is established to simulate the ETC launch. According to the measured pressure and electrical parameters, a transient burning rate law including the influence of EGGR coefficient by electric power and pressure gradient(dp/dt) is added into the model. The EGGR coefficient of 4/7 high-nitrogen solid propellant is equal to 0.005 MW-1. Both simulated breech pressure and projectile muzzle velocity accord with the experimental results well. Compared with Woodley's modified burning rate law, the breech pressure curves acquired by the transient burning rate law are more consistent with test results. Based on the parameters calculated in the model, the relationship among propellant burning rate, pressure gradient(dp/dt) and electric power is analyzed. Depending on the transient burning rate law and experimental data, the burning of solid propellant under the condition of plasma is described more accurately.

Tissue-engineered Epithelium Transplantation for Severe Ocular Surface Burns

Purpose:To evaluate the clinical outcomes of tissue -engineered epithelium transplantation for severe ocular surface burns. Methods:This was a retrospective observational case series. From October 2005 to May 2011, 19 eyes of 19 patients with grade IV to VI ocular surface burns (Dua Classification) were treated by autologous transplantation of corneal stem cells cultivated on a fibrin gel membrane,with a mean follow-up of 16.2 months (range 12-36 months). Postoperative corneal surface stability, visual acuity (VA), corneal opacity, and neo- vascularization were evaluated. Results:No corneal perforations occurred and the entire corneal surface was free from epithelial defects in all eyes. At the final follow-up visit,VA in 17 eyes was improved after surgery,with 6 eyes achieving a VA of 20 / 100 or better. Corneal vascularization was significantly reduced in 17 (89.5% ).eyes.Corneal opacity was also improved in 12 (63.2%) eyes. All donor eyes remained healthy. Conclusion:Tissue-engineered epithelium transplantation can promote rapid reepithelialization of the ocular surface, inhibit corneal neovascularization,and improve vision for patients with severe ocular surface burns.(Eye Science 2013;.28:24- 29)

Acute surgical vs non-surgical management for ocular and peri-ocular burns:a systematic review and meta-analysis

Background:Burn-related injury to the face involving the structures of the eyes,eyelids,eyelashes,and/or eyebrows could result in multiple reconstructive procedures to improve functional and cosmetic outcomes,and correct complications following poor acute phase management.The objective of this article was to evaluate if nonsurgical or surgical interventions are best for acute management of ocular and/or peri-ocular burns.Methods:This systematic review and meta-analysis compared 272 surgical to 535 non-surgical interventions within 1 month of patients suffering burn-related injuries to 465 eyes,253 eyelids,90 eyelashes,and 0 eyebrows and evaluated associated outcomes and complications.The PubMed,Embase,Cochrane Library,Web of Science,and Scopus databases were systematically and independently searched.Patient and clinical characteristics,surgical and medical interventions,outcomes,and complications were recorded.Results:Eight of the 14,927 studies queried for this study were eligible for the systematic review and meta-analysis,with results from 33 of the possible 58 outcomes and complications using Preferred Reporting Items for Systematic Reviews and Meta-analysis(PRISMA)and Cochrane guidelines.Surgery was associated with standard mean differences(SMD)0.44 greater visual acuity on follow-up,SMD 1.63mm shorter epithelial defect diameters on follow-up,SMD 1.55 mm greater changes in epithelial diameters from baseline,SMD 1.17 mm^(2) smaller epithelial defect areas on follow-up,SMD 1.37 mm^(2) greater changes in epithelial defect areas from baseline,risk ratios(RR)1.22 greater numbers of healed epithelial defects,RR 11.17 more keratitis infections,and a 2.2 greater reduction in limbal ischemia compared to no surgical intervention.Conclusions:This systematic review and meta-analysis found that compared to non-surgical interventions,acute surgical interventions for ocular,eyelid,and/or eyelash burns were found to have greater visual acuity on follow-up,shorter epithelial defect diameters on follow-up,greater changes in epithelial diameters from baseline,smaller epithelial defect areas on follow-up,greater changes in epithelial defect areas from baseline,greater numbers of healed epithelial defects,more keratitis infections,and a greater reduction in limbal ischemia,possibility preventing the need of a future limbal stem cell transplantation.

Burning rate analysis of laser controlled 5-aminotetrazole propellant

As an innovative propulsion technique, laser augmented chemical propulsion(LACP) seems superior to the traditional ones. However, the corresponding combustion theories have still to be ascertained for LACP. Burning rate of 5-aminotetrazole(5-ATZ) propellant has been studied by testing pressed samples under different combustor pressures and laser powers. Based on micro computed tomography(Micro CT),an advanced thickness-over-time(TOT) method to characterize the regression of the produced nonplanar burning surface is established. Because of a shell structure covering the combustion surface,the burning rate of the implemented 5-ATZ propellant is not constant during laser ablation. Resorting to functional fitting, a new law of non-constant burning including the effect of the observed unique burning surface structures is proposed. Accordingly, applicable combustion conditions of 5-ATZ based propellants have been preliminarily speculated for future research activities.

Chemical characterization and source apportionment of PM_(1) and PM_(2.5) in Tianjin, China: Impacts of biomass burning and primary biogenic sources

The submicron particulate matter(PM_(1))and fine particulate matter(PM_(2.5))are very important due to their greater adverse impacts on the natural environment and human health.In this study,the daily PM_(1) and PM_(2.5) samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin,China.The collected samples were analyzed for the carbonaceous fractions,inorganic ions,elemental species,and specific marker sugar species.The chemical characterization of PM_(1) and PM_(2.5) was based on their concentrations,compositions,and characteristic ratios(PM_(1)/PM_(2.5),AE/CE,NO3^-/SO4^2-,OC/EC,SOC/OC,OM/TCA,K^+/EC,levoglucosan/K^+,V/Cu,and V/Ni).The average concentrations of PM_(1) and PM_(2.5) were 32.4μg/m and 53.3μg/m^3,and PM_(1) constituted 63%of PM_(2.5) on average.The source apportionment of PM_(1) and PM_(2.5) by positive matrix factorization(PMF)model indicated the main sources of secondary aerosols(25%and 34%),biomass burning(17%and 20%),traffic emission(20%and 14%),and coal combustion(17%and 14%).The biomass burning factor involved agricultural fertilization and waste incineration.The biomass burning and primary biogenic contributions were determined by specific marker sugar species.The anthropogenic sources(combustion,secondary particle formation,etc)contributed significantly to PM_(1) and PM_(2.5),and the natural sources were more evident in PM_(2.5).This work significantly contributes to the chemical characterization and source apportionment of PM_(1) and PM_(2.5) in near-port cities influenced by the diverse sources.

Physical and chemical effects of phosphorus-containing compounds on laminar premixed flame

Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will increase the burning velocity under lean-burn conditions, and this indeed posed potential threats to the fire prevention and fighting. To seek deeper insights into the reaction process, a numerical investigation was actualized to study the phosphorus-related effects on methane-air flames. By replacing a phosphorus-related inhibitor with the corresponding decomposed molecules, the detailed promoting and inhibiting effects of combustion were separated from the general chemical effect. A comparative study was carried out to identify the interaction between the two effects under different combustion conditions. It is observed that the promoting effect becomes the dominant factor during the reaction process when the equivalence ratio is smaller than 0.60. In this lean-burn condition, the exothermic reactions were faster than the others within the reaction chains due to the reduction of radical recombination in hydrocarbon oxidation. The results are believed to be useful for the further application and improvement of flame inhibitors.

Decreasing incidence of cutaneous chemical burns in a resource limited burn centre: is this a positive effect of modernization?

Background: Burns present a devastating injury to patients. Burns caused by chemical agents, present a worse scenario. In a resource limited country like Nigeria, readily available sources of these corrosive agents are mainly from lead-acid battery vendors and to some extent local small scale soap manufacturers who use caustic soda. We hypothesized that with the reduction in small scale soap manufacturing and increasing trend towards modernization in the use of dry cell batteries, chemical burns may be on the decline, and we sought to investigate this. Methods: The records of all acute burn patients seen at the Burns and Plastic Department of the National Orthopaedic Hospital Enugu Nigeria between January 2011 and December 2014 were retrospectively reviewed. The results were compared to similar studies carried out at the same centre. A questionnaire was administered to corrosive chemical (sulphuric and caustic soda) vendors to assess the trends in product sales and use in recent times. Results: A total of 624 acute burn cases were treated during the period;among which, 12 cases (1.9%) were chemical burns. When compared with previous studies at the centre, Chemical burn cases were recorded as the lowest rate. The median age of patients was 24 years. There were eight males and four females. Interpersonal assault was the commonest mechanism of injury with sulphuric acid suspected to be the commonest agent in 83.3% of the cases, while 16.7% of the cases were from accidental use of caustic soda. The head and neck as well as the upper limbs were the most affected (30%). Twenty-six questionnaires to lead-acid vendors were analyzed and revealed that all respondents noticed a marked downward trend in the sale of either sulphuric acid or caustic soda, and they attributed this to the ready availability of imported alternatives to locally manufactured soap or wet lead-acid batteries. Ease of use, durability and convenience of the dry cell batteries were cited as principal reasons. Conclusion: There appears to be a downward trend in the prevalence of chemical burns in our study compared to previous studies in the centre which may be due to reduced availability and access of corrosive chemicals to the general public. Further prospective multicentre studies to confirm this are recommended.

Inhibitory effect of polysulfated heparin endostatin on alkali burn induced corneal neovascularization in rabbits

AIM: To investigate anti-angiogenic effects of polysulfated heparin endostatin(PSH-ES) on alkali burn induced corneal neovascularization(NV) in rabbits.METHODS: An alkali burn was made on rabbit corneas to induce corneal NV in the right eye of 24 rabbits. One day after burn creation, a 0.2 m L subconjunctival injection of 50 μg/m L PSH-ES, 50 μg/m L recombinant endostatin(ES), or normal saline was administered every other day for a total of 14d(7 injections). Histology and immunohistochemisty were used to examine corneas.Corneal NV growth was evaluated as microvessel quantity and corneal vascular endothelial growth factor(VEGF)expression was measured by immunohistochemical assay.RESULTS: Subconjunctival injection of ES and PSHES resulted in significant corneal NV suppression, but PSH-ES had a more powerful anti-angiogenic effect than ES. Mean VEGF concentration in PSH-ES treated corneas was significantly lower than in ES treated and saline treated corneas. Histological examination showed that corneas treated with either PSH-ES or ES had significantly fewer microvessels than eyes treated with saline. Additionally corneas treated with PSH-ES had significantly fewer microvessels than corneas treated with ES.CONCLUSION: Both PSH-ES and recombinant ES effectively inhibit corneal NV induced by alkali burn.However, PSH-ES is a more powerful anti-angiogenic agent than ES. This research has the potential to provide a new treatment option for preventing and treating corneal NV.

Chemical Characterization of PM10 Particulate Matter in the Ambient Air of a Region of Central Italy (Umbria)

Atmospheric particulate matter is a critical factor for many regional urban areas of Umbria (Central Italy region). During 2013 the monitoring air quality network, managed by ARPA Umbria, has been upgraded to Legislative Decree of 13 August 2010, n.155 and an analytical study about chemical composition of PM10 (Particulate Matter with diameter of 10 micrometres or less) over all the region has been started. The PM10 filters have been analyzed for Benzo(α)Pyrene, Pb, Cr, Ni and Cd to check compliance with limits or target values defined in Italian regulation (Legislative Decree of 13 August 2010, n.155);other parameters, like US-EPA list Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Dibenzo-p-Dioxins and Polychlorinated Dibenzo Furans (PCDD/ Fs), Polychlorinated Biphenyls (PCBs), Organic Carbon/Elemental Carbon (OC/EC) and Levoglucosan were analyzed because they are toxic or because they identify particular pollutant sources. The data obtained showed a large and diffusive biomass burning contribution, widely used in the Umbria Region both for domestic heating in traditional fireplaces and for combustion of pruning residues. In particular the urban sites of Terni and suburban site near Terni (Narni), both lying in the Terni basin called “Conca Ternana”, showed a chemical composition of PM10 that suggests a very large anthropization. This area is the principal industrial reality in the Central Italy because there is a steel production plant, a Municipal solid waste (MSW) burning plant and a chemical plant.

Beyond the burn: Studies on the physiological effects of flamethrowers during World War Ⅱ

Flamethrowers are widely considered one of warfare’s most controversial weapons and are capable of inflicting gruesome physical injuries and intense psychological trauma.Despite being the last of the major combatants in World WarⅡ(WWⅡ)to develop them,the U.S.military quickly became the most frequent and adept operator of portable flamethrowers.This gave the U.S.military ample opportunity to observe the effects of flamethrowers on enemy soldiers.However,while most people in modern times would consider immolation by flamethrower to be an unnecessarily painful and inhumane way to inflict casualties,immolation was,at one point during WWⅡ,referred to as"mercy killing"by the U.S.Chemical Warfare Service(CWS).This mischaracterization arose from a series of firsthand accounts describing what were believed to be quick,painless,and unmarred deaths,as well as from a poor and incomplete understanding of flamethrower lethality.As a result,indirect mechanisms such as hypoxia and carbon monoxide poisoning were generally absent from accounts of the flamethrower’s fatal effects.It was not until several years after flamethrowers were introduced to the frontlines that the CWS and National Defense Research Committee(NDRC)conducted a series of tests to better understand the physiological and toxicological effects of flamethrowers.This article examines how the initial absence of scientific data on the physiologic effects of flamethrowers led to an inaccurate understanding of their lethality,and bizarre claims that one of history’s most horrific instruments of war was considered one of the more"humane"weapons on the battlefield.

Burning surface formation mechanism of laser-controlled 5-aminotetrazole propellant

As an innovative propulsion technique, combustion mechanism of laser-augmented chemical propulsion has still to be ascertained. Benefiting from high nitrogen content and thermal stability, 5-aminotetrazole is a suitable ingredient for LACP. Under a flowing nitrogen environment, two kinds of unique burning surfaces were observed to occur for 5-ATZ, used as a single reacting propellant ingredient with the addition of carbon, under laser ablation. Both surfaces are hollow structures and differ by the possible presence of edges. Using micro computed tomography, the 3D perspective structures of both surfaces were revealed. Resorting to various characterization methods, a unified formation mechanism for both surfaces is proposed. This mechanism specifically applies to laser ablation, but could be crucial to common burning mechanisms in LACP.

Serious Burn by Sulfuric Acid: Case Report of Particular Therapeutic Strategy in a Non-Specialized ICU at Hôpital Principal de Dakar (HPD) Sénégal

Managing severe burns remains problematic due to the lack of specialized units, but also because of the delay in implementing emergency care. The aim is to show that an adapted strategy, can lead to satisfying management of chemical burns. The authors report retrospectively the case of a patient admitted for chemical burns, and treated in a non-specialized intensive care unit;a 38 years old male, referred for burns by sulfuric acid at his workplace. On admission to H15, the clinic did not reveal any vital organs failure. Burns were localized on two legs and soles of the two feet (18% TBSA). Treatment combined daily dressings with silver sulfadiazine. On day 14, the wound healing associated occlusive gauze dressing, iodine cream application, and mechanical debridement. On day 47, a 5% dermal autograft performed on right foot favored with good attachment grafts. On day 58, the patient was released after complete skin recovery. Then, in a non-specialized burn unit and without early surgery access, our wound healing adapted strategy was successful. In Senegal, chemical burns represent about 2.5% of burn cases. They are often from accidents on occupation job, while generally in Africa chemical burns result from criminal attacks. Patients with severe lesions are admitted in non-specialized environments after an extended time of transfer, and don’t have efficient initial care. This may explain the high morbidity and mortality after burns in our country. The lack of surgical facilities such as skin substitutes, in non-specialized unit on low or median income countries (LMICs), explains this long period of wound healing. The treatment of severe burn in LMICs is hazardous.

Transplantation of corneal stem cells cultured on amniotic membrane for corneal burn: experimental and clinical study

OBJECTIVE: To investigate the proliferation and differentiation of cultured corneal stem cells and determine the effect of corneal stem cells cultured on amniotic membranes on the limbal area for treating corneal burns. METHODS: The proliferation and differentiation of corneal stem cells in vitro had been examined using colony-forming efficiency and immunohistochemistry. The stem cells had been cultured on amniotic membranes and transplanted to the limbal area for treating corneal burns. RESULTS: Corneal stem cells had a high proliferation capacity in primary and first passage, cytokeratin 3 was not expressed in primary culture but partly in first passage. The stem cells could proliferate to form cell layer on an amniotic membrane. When transplanted, stem cells could survive on limbus. After transplantation, ocular inflammation resolved, the cornea re-epithelialized, the stromal opacity reduced, the superficial neovascularity was lessened and the conjunctival fornix re-established. CONCLUSIONS: Ocular surface conditions could be improved by allograft of corneal stem cells cultured on amniotic membranes.

Paediatric burns secondary to nail adhesives: a case series

Background:Nail adhesives are widely available beauty products that are used in the cosmetic industry and households to attach false nails.Nail adhesive burns are uncommon,and it is crucial that healthcare providers and the public are aware of its potential to cause chemical burn.Case Presentation:Case series of accidental burns secondary to cyanoacrylate nail glue treated at the Welsh Centre for Burns and Plastic Surgery(WCBPS)in Swansea,United Kingdom.Conclusion:All of the burns were observed in children and occurred due to accidental spillage.Therefore,it is important for the public to be aware that nail glue is a chemical agent which should be stored safely away from the reaches of young children.The case series highlights the importance of first aid in reducing the severity of chemical burns secondary to the nail adhesives,and its early recognition and treatment are emphasised.

Transplantation of human limbal cells cultivated on amniotic membrane for reconstruction of rat corneal epithelium after alkaline burn

BACKGROUND: The transplantation of limbal epithelial cells cultivated on amniotic membrane is a newly developed treatment for limbal stem cell deficiency. The purpose of our study was to investigate the biological characteristics of limbal epithelial cells and evaluate the effect of transplantation of cultivated human limbal epithelial cells on ocular surface reconstruction in limbal stem cell deficiency rat model. METHODS: Human limbal cells were isolated and cultivated in vitro. Cytokeratins 3, 12, and 19 (K3, K12 and K19) and p63 were detected by immunofluorescent staining or RT-PCR. BrdU labelling test was used to identify the slow cycling cells in the cultures. Limbal stem cell deficiency was established in rat cornea by alkali burn. Two weeks after injury, the rats received transplants of human limbal stem cells cultivated on amniotic membrane carrier. The therapeutic effect was evaluated by slit lamp observation, Hemotoxin and Eosin (HE) staining and immunofluorescent staining. RESULTS: On day 7 in primary culture, p63 and K19 were strongly expressed by most cells but only a few cells expressed K3. On days 14 and 21, p63 and K19 were still expressed by a majority of cells, but the expressive intensity of p63 decreased in a number of cells, while the proportion of K3 positive cells increased slightly and some cells coexpressed p63 and K3. RT-PCR showed that gene expression of both p63 and K12 were positive in cultivated limbal cells, but in mature superficial epithelial cells, only K12 was detected. BrdU labelling test showed that most cells were labelled with BrdU after 7 days' labelling and BrdU label retaining cells were observed after chasing for 21 days with BrdU free medium. For in vivo test, slit lamp observation, HE staining and immunofluorescent staining showed that the rats receiving transplant of human limbal stem cells cultivated on amniotic membrane grew reconstructed corneas with intact epithelium, improved transparency and slight or no neovascularization. A majority of epithelial cells of the reconstructed cornea were positive to antihuman nuclear antibody and cells expressing K3 were found mainly in superfacial epithelium. CONCLUSIONS: Limbal stem cells can be cultivated in vitro: the cells are characterized by high proliferation and slow cycling and identified as p63/K19 positive and K3/K12 negative. During culture, some stem cells can proliferate and differentiate into mature cornea epithelial cells. Amniotic membrane is a suitable carrier for limbal stem cells. Transplantation of human limbal stem cells cultivated on amniotic membrane can functionally reconstruct rat cornea with limbal stem cell deficiency.

常见化学烧伤的救治方法

随着新化工产品的不断涌现,化学烧伤在工作中发生率明显升高,化学烧伤的损伤一般发生在工作环境中,严重程度和化学品的性质、剂量、浓度、接触时间和接触面积、急救措施等有着密切的关系。目前较多医疗机构内缺乏化学烧伤救治的标准操作流程,本文通过介绍常见局部化学烧伤的处理的基本原则,为临床治疗提供参考。