Efficiency of amniotic membrane transplantation in the management of limbal stem cell deficiency

State University of Medicine and Pharmacy “Nicolae Testemiţanu”, Department of Ophthalmology-Optometry, Chișinău, Republic of Moldova, State University of Medicine and Pharmacy “Nicolae Testemiţanu”, Department of Surgery no. 2, Chișinău, Republic of Moldova, State University of Medicine and Pharmacy “Nicolae Testemiţanu”, Department of Medical Rehabilitation, Physical Medicine and Manual Therapy, Chișinău, Republic of Moldova, Laboratory of Tissue Engineering and Cell Cultures, Chișinău, Republic of Moldova, Congresul consacrat aniversării a 75-a de la fondarea USMF ”Nicolae Testemițanu” 21-23 octombrie 2020Abstract. Objectives. This paper aims to examine the efficacy, safety, and long term outcomes of amniotic membrane transplantation for corneal surface reconstruction, in cases of limbal stem cell deficiency. Material and methods. A systematic literature search was performed on PubMed, for papers published up to February 2020, using the following combined search terms: "limbal stem cell deficiency", "amniotic membrane", "limbal transplant". Only clinical trials with human subjects were selected for analysis. We collected the data on amniotic membrane properties and mechanisms of action, processing, preservation and transplantation techniques, and clinical outcomes of different treatment methods. Results. The surgical approach for treating limbal stem cell deficiency depends on the extent of the disease. Isolated amniotic membrane transplantation appears to have a limited beneficial effect on limbal stem cells, whereas amniotic membrane transplantation, combined with certain types of limbal stem cell transplantation, provides long-term biological and mechanical support for the donor tissue explants. Combined with simple limbal epithelial transplantation, the amniotic membrane has shown excellent results in the surgical management of limbal stem cell deficiency. Conclusions. Preliminary results of amniotic membrane use in limbal transplantation show quite satisfactory data, but the lack of high-level randomized controlled studies makes it difficult to assess the comparative efficacy of amniotic membrane transplantation in limbal stem cell deficiency surgical management

Amniotic membrane transplantation in ophthalmology: indications and techniques

Introduction: The human amniotic membrane (HAM) has been proved to possess a multitude of beneficial effects - stimulation of epithelialization, antiangiogenic, antibacterial and antiinflamatory effects, which can be very useful in many ophthalmological indications, such as corneal trophic ulcers resistant to medication and some cases of ocular surface destruction. Besides evaluating the efficiency of the HAM transplantation in this paper, we tried to describe our experience with amniotic membrane in the treatment of ocular surface abnormalities. Purpose and objectives: To introduce the HAM transplantation indications in ophtalmology, to present the methods an techniques of HAM aplication on the human eye, to describe our experience with the amniotic membrane and to analyse the transplantation outcomes in patients with corneal ulcers of diverse etiology. Materials and methods:19 patients were included in the study. All of them underwent HAM transplantation from December 2014 to March 2015, at the MCH „St. Trinity”. The patients presented corneal ulcers of diverse complexity and etiology and were distributed in 3 main categories: group A (n=14), which included patients with corneal erosions in dry eye syndrome (n=5), viral keratitis (n=6), persistent epithelial defects after corneal abscess (n=2) and chemical burns (n=1); group B (n=4), which included patients with severe stromal thinning and iminent corneal perforation; group C (n=1), with one case of symblepharon and extensive corneoconjunctival adhesions. The HAM was prepared from a fresh placenta of a seronegative pregnant woman and stored at -80°C. In all cases the amniotic membrane was applied on the ocular surface using the „patch” technique only. Results: The cornea regenerated satisfactory in 11 patients out of 14 in group A, but the epithelial defect recurred in 3 of these cases. In the second group the transplantation was less effective - 2 patients out of 4 needed further tectonic corneal graft and 1 penetrant keratoplasty was performed. The HAM transplantation showed good results in symblepharon surgery, facilitating epithelialization and preventing corneo-conjunctival adhesions in the group C. Conclusions: The HAM transplantation proved efficient in facilitating corneal healing and regeneration in patients with persistent epithelial defects, as well as preventing corneo-conjunctival adhesions following symblepharon surgery. Nevertheless, in some cases, further surgery was needed for ocular surface reconstruction. The HAM transplantation wasn’t effective enough to prevent the tectonic corneal graft if severe stromal thinning and impending corneal perforation were involved

Membrana amniotică: sursă de tratament al defectelor cutanate la pacienții diabetic

Background. The amniotic membrane has a number of unique properties: anti-inflammatory, bacteriostatic, a capacity for maximum reepithelialization of the affected tissue; so being an attractive method of grafting tissue defects, especially at diabetic patients. Objective of the study. To evaluate the efficacy of scar healing in diabetic patients by amniotic membrane treatment. Material and Methods. It was initiated a study on 10 diabetic patients with chronic ulcers, lasting more than 1 month. Patients were divided into two groups: the first group (control group) included 5 patients whose tissue defects were treated with a split free skin graft. The other group of 5 patients with tissue defects was treated with amniotic membrane, which was obtained and prepared initially and then applied. Results. In the control group at 2 patients, the tissue defect was completely healed, and at 3 patients the free skin graft was rejected. In the other group where was used the amniotic membrane, was obtained a complete healing with a duration of 14-60 days. Conclusion. Amniotic membrane can be a perfect source of treatment for defects at patients with diabetes, replacing conventional treatment. Introducere. Membrana amniotică, având o serie de proprietăți unice: antiinflamatorie, bacteriostatică, o capacitate de reepitelizare maximă a țesutului afectat, este o metodă atractivă de grefare a defectelor de țesut, îndeosebi la pacienții diabetici. Scopul lucrării. Evaluarea eficacității de cicatrizare a defectului la pacienții diabetici prin tratamentul cu membrană amniotică. Material și Metode. A fost inițiat un studiu pe 10 pacienți diabetici cu ulcere cronice, cu o durată mai mare de 1 lună. Pacienții au fost împărțiți în două grupuri: primul grup (grup control) a inclus 5 pacienți ale căror defecte de țesut au fost tratate cu grefă de piele liberă despicată. Celălalt grup de 5 pacienți cu defecte de țesut, a fost tratat cu membrana amniotică, obținută și preparată inițial. Rezultate. În grupul control, la 2 pacienți defectul de țesut a fost cicatrizat totalmente, iar la 3 pacienți grefa de piele liberă a fost respinsă. În celălalt grup unde am utilizat membrana amniotică, s-a obținut o cicatrizare completă cu o durată de 14-60 de zile. Concluzii. Membrana amniotică poate fi o sursă perfectă de tratament al defectelor la pacienții diabetici, înlocuind tratamentul convențional

Could human amniotic membrane be a source for acupoint thread embedding therapy?

Background: Peripheral neuropathy usually leads to a major cause of motor disability, but the functional restoration after treatment continues to show modest results. Acupoint thread-embedding therapy is a subtype of acupuncture treatment in which biodegradable threads are inserted into skin, subcutaneous tissue or muscles at specific points for long stimulation. Different biodegradable materials have been developed and widely used. Human amniotic membrane is rich in collagen, extracellular matrix proteins and growth factors. The avascular, low immunogenic, anti-inflammatory, antibacterial, anti-fibrotic and non-tumorigenic properties of amniotic membrane make it valuable in medical applications and its use has no ethical problems. Elasticity, stiffness and other biomechanical properties also make it possible to use the amniotic membrane for various medical purposes. AM is almost always considered as discarded substance, it satisfies most of the criteria of an ideal biological tissue and shows almost zero rejection phenomenon. Conclusions: The human amniotic membrane, the cellular compounds and extracellular matrix have a lot of benefic proprieties that are or could be used in treatment of many human diseases. Its biological and biomechanical properties are promising in the manufacture and use of filaments in acupoint thread embedding therapy

Review-ul literaturii în utilizarea membranei amniotice în plăgi, la nivelul membrelor inferioare, la pacienţii diabetici

Laboratory of Tissue Engineering and Cell Cultures, Department of Orthopedics and Traumatology, Department of Ophthalmology, Nicolae Testemitanu SUMPhBackground: Primary or secondary circulatory disorders, in the lower limbs, often produce complications that can lead to irreversible changes with lesions because of lack of substance, with slowly healing chronic evolution. Objective of the study. To evaluate the effectiveness of wound regeneration with the use of amniotic membrane in diabetic patients according to the studied cases. Material and Methods. Several information search pages were used: Pubmed, Cochrane Library, Google Scholar, Research Gate, with the keywords "transplant", "amniotic membrane", "wound" and "diabetic foot". The search interval was 2010 and 2020 years. Experimental studies and observational studies were evaluated. The healing time of the wounds was taken into account. Results.The search strategy identified 315 studies, of which only 8 studies were eligible for the established criteria. In the studied literature, there is a debate about the ideal therapeutic effects in the case of wounds. Amniotic membrane has superior results and the minimum number of side effects attributed to conservative or surgical treatment. Conclusion. According to the studies review, in case of using the amniotic membrane, there was a higher rate of wound healing over time, compared to the group of patients with conventional treatment. As the number of data is small, we consider it necessary to continue studies in this field.Introducere. Tulburările circulatorii primitive sau secundare la nivelul membrelor inferioare produc deseori complicaţii, ce pot genera modificări ireversibile, cu leziuni prin lipsă de substanţă cu evoluţie cronică lent vindecabilă. Scopul lucrării. Evaluarea eficacităţii regenerării plăgilor cu folosirea membranei amniotice, la pacienţii diabetici, după cazurile studiate. Material și Metode. Au fost folosite mai multe pagini de căutare a informaţiei: Pubmed, Cochrane Library, Google Scholar, Research Gate, cu cuvintele-cheie: transplant; membrană amniotică; plagă şi picior diabetic. Intervalul de căutare a fost pentru perioada anilor 2010 şi 2020. Au fost evaluate studii experimentale şi studii observaţionale. S-a luat în considerare timpul de vindecare a plăgilor. Rezultate. Strategia de căutare a identificat 315 studii, dintre care doar 8 studii erau eligibile criteriilor stabilite. În literatura studiată există o dezbatere legată de efectele terapeutice ideale în cazul plagilor: membrana amniotică deţine rezultate superioare şi numărul de efecte adverse minim atribuit tratamentului conservator sau chirurgical. Concluzii. Conform review-ului studiilor, în cazul utilizării membrane amniotice, s-a constat o rată mult mai înaltă de vindecare a plăgii în timp, în comparaţie cu grupul de pacienţi cu tratamentul convenţional. Numărul de date fiind mic, considerăm necesar continuarea studiilor în acest domen

The impact of culture media on the endothelial viability of corneas

Background: The complexity of cryopreservation and its potential to damage the endothelium make it so that it is rarely used in routine eye banking, except for occasional, clinically urgent transplants, where the main objective is to save the eye. The culture medium was the method of choice in the Eye Bank. Material and methods: The study group was divided into 3 subgroups. For penetrating keratoplasty and anterior lamellar keratoplasty, corneas taken up to 24 hours, with a number greater than 2000 endothelial cells per mm2 , are preferably used. Results: In the first group we found: weakly edematous epithelium; thin, transparent stroma; thin Descemet’s membrane; transparent endothelial layer, endothelial cell density greater than 2800 cells/mm2. The corneas of the second group presented: edematous, but with uncompromised integrity epithelium; slightly edematous, transparent stroma; slightly folded Descemet’s membrane; intact endothelial layer and an average of 2600 cells/mm2. Corneas of the third group: evidently edematous epithelium, with exfoliations in some areas and Bowman’s membrane detachment; considerable edema of stroma in all layers; pronounced folds of Descemet’s membrane; interrupted endothelial layer along the outline of the folds. Conclusions: The age of the donor and the preservation time are important factors that influence corneas in culture media and determine the state of endothelial cells. Although the number of endothelial cells usually decreases with age, there are still many corneas from donors over 80 years of age who meet the minimum criteria for transplantation

Clinical manifestations, contemporary diagnosis and treatment of chronic myeloid leukemia

State University of Medical and Pharmacy “Nicolae Testemitanu”, Chisinau, Republic of MoldovaIntroduction: Chronic myeloid leukemia (CML) is a myeloproliferative disorder that results from the reciprocal translocation of the ABL1 gene on chromosome 9 with the BCR gene on chromosome 22, leading to the formation of the chimeric fusion oncogene. This myeloproliferative malignancy accounts 15-20% of leukemias in adults. The course of CML istriphasic: chronic phase (asymptomatic in approximately 30% of cases) followed by an advanced accelerated phase and/or blast crisis, which may prove fatal. The treatment of CML has evolved over the years and currently includes oral tyrosine kinase inhibitors, immunotherapy and bone marrow transplantation. Imatinib was the first tyrosine kinase inhibitor to be introduced as first-line therapy. Purpose and Objectives: Evaluation of clinical manifestations, contemporary methods of diagnosis, assessment of therapeutic possibilities and treatment outcomes in patients with CML. Materials and methods: The study was based on the analysis of the clinical observation sheets of 50 patients diagnosed with CML. Results: The study included 50 patients aged from 20 to 81 years: 28 men (56%) and 22 women (44%). According to the study, CML starts most frequently at the age o f 46-50 years (18%). 46 (92%) patients were diagnosed with CML in chronic phase. Only 3(6%) patients were diagnosed during the acceleration phase and 1 (2%) patient - during the acute phase. 9 (18%) patients were asymptomatic at the moment of diagnose. At least 35 (70%) patients presented a certain degree of splenomegaly; 40 (80%) patients-asthenia, 37 (74%) patients- pressure in the left hypochondrium; 15 (30%) patients- bodyweight loss. 46 (92%) patients received chemotherapy, 37 (74%) patients (74%) were treated with Imatinib. Only 2(4%) patients received Imatinib as a first line therapy. 36 (72%) patients had a complete remission (68% ensured by Imatinib); 14 (28%) patients - partial remission (ensured by conventional therapy). In the first 6 months o f treatment, Imatinibdetermined CMR in 5 (10% ) cases, CCR in 7 (14%) cases and CHR in 22(48%) cases. Only 3(6%) patients experienced a relapse in less than a year after remission with Imatinib. On the other hand,8(16%) patients with conventional therapy experienced recurrence during the same period of time. Conclusion: The tyrosine kinase inhibitors represent the current most efficient therapy for CML in chronic phase. The treatment discontinuation is almost invariably followed by a recurrence. The introduction of targeted therapy has transformed this disease from an incurable malignancy to a manageable chronic condition