Carmen Martinez- Garcia

University of Valladolid | UVA · Department of Cell Biology, Histology and Pharmacology

The organization of the corneal stoma is modified due to different factors, including pathology, surgery or external damage. Here the changes in the organization of the corneal collagen fibers during natural healing after chemical burn are investigated using second harmonic generation (SHG) imaging. Moreover, the structure tensor (ST) was used as a...

Purpose: Photoactivated cornea collagen cross-linking (CXL) increases corneal stiffness by initiating formation of covalent bonds between stromal proteins. Because CXL depends on diffusion to distribute the photoinitiator, a gradient of CXL efficiency with depth is expected that may affect the degree of stromal collagen organization. We used secon...

Purpose: To compare the clinical and histological outcomes after intrastromal corneal ring segment (ICRS) implantation with and without plasma rich in growth factors (PRGF) in an experimental animal model. Materials and methods: First, the toxicity of PRGF was tested in hen's keratocyte cultures. Then, an animal model with 18 hens was randomly d...

The extracellular matrix (ECM) confers transparency to the cornea because of the precise organization of collagen fibrils and a wide variety of proteoglycans. We monitored the corneal wound healing process after alkali burns in rabbits. We analyzed the location and expression of collagens and proteoglycans, the clinical impact, and the recovery of...

Corneal cross-linking (CXL) is a surgical procedure able to modify corneal biomechanics and stabilize keratoconus progression. Although it is known that CXL produces changes in corneal collagen distribution, these are still a topic of discussion. Here we quantitatively compare the corneal stroma architecture between two animal models four weeks aft...

Purpose: To study corneal wound healing after two cross-linking techniques using either rose bengal and green light (RGX) or the conventional treatment using riboflavin and UVA radiation (UVX). Methods: Corneas of New Zealand rabbits were monolaterally treated with UVX (21 eyes) or RGX (25 eyes). Treatments involved corneal de-epithelialization...

Nidogen-2 is a basement membrane (BM) glycoprotein that could be a key to understanding why defects in BM regeneration occur after severe trauma to the cornea. We monitored the location and expression of nidogen-2 during corneal repair after alkali burn in rabbits. In rabbits that received both general and ocular topical anaesthesia, the central co...

Purpose: To evaluate corneal wound healing after treatment with a new collagen crosslinking protocol using rose bengal dye and green light (RGX). Methods: One cornea of 20 New Zealand rabbits was de-epithelialized (DE) in an 8-mm diameter circle and, in another group (n = 25), the DE corneas were then stained with 0.1% rose bengal for 2 minutes...

In an effort to improve the regenerative nature of corneal repair, this study reports the use of an in vitro human corneal fibroblasts (HCFs) wound model after treatment with three of the main growth factors (GFs) involved in corneal healing: transforming growth factor beta 1 (TGFβ1), platelet-derived growth factor BB-isoform (PDGF-BB), and basic f...

Purpose: To compare corneal biomechanical properties after in vivo and ex vivo cross-linking (CXL) using rose bengal-green light (RGX) or riboflavin-UVA (UVX). Methods: Corneas of 30 rabbits were treated in vivo by the two CXL modalities monolaterally (Group 1) or bilaterally (Group 2). Rabbits in Group 1 were euthanized 1 month after treatments...

The development of treatments that modulate corneal wound healing to avoid fibrosis during tissue repair is important for the restoration of corneal transparency after an injury. To date, few studies have studied the influence of growth factors (GFs) on human corneal fibroblast (HCF) expression of extracellular matrix (ECM) proteins such as collage...

Aim To compare the histological, morphological and the biophysical measurements between hen and quail corneas, in order to determine which of them were better suited for use as an animal model for research into corneal refractive surgery. Material and methods A study was performed using the biophysical measurements of the cornea (curvature, thickn...

Purpose: The aim was to evaluate the reversibility of the clinical and histological changes induced in the corneas of an animal model after removing an intracorneal ring segment (ICRS). Methods: Surgery for this study was performed in 38 eyes of an experimental animal model (Gallus domesticus) for ICRS surgery (Ferrara technique). The animals wi...

Aim: To compare the histological, morphological and the biophysical measurements between hen and quail corneas, in order to determine which of them were better suited for use as an animal model for research into corneal refractive surgery. Material and methods: A study was performed using the biophysical measurements of the cornea (curvature, th...

To evaluate corneal wound healing in the hen animal model after additive surgery with an intracorneal ring segment (ICRS). We implanted one ICRS in each eye of 76 hens. In control group 1 (n = 22 hens), the stromal channel was prepared but no ICRS was inserted. In control group 2 (n = 2 hens), no surgery was performed. Animals were randomly separat...

Purpose: In this study, we investigated the wound-healing process after photorefractive keratectomy with mitomycin C (MMC) in hen corneas. In addition, we evaluated the synergistic effect of ethanol and MMC. Methods: Forty-eight adult hens were divided into 3 groups: A: ethanol-assisted debridement plus MMC; B: mechanical debridement plus MMC; a...

Pollen is the most common aeroallergen to cause seasonal conjunctivitis. The result of allergen exposure is a strong Th2-mediated response along with conjunctival mast cell degranulation and eosinophilic infiltration. Oleanolic acid (OA) is natural a triterpene that displays strong anti-inflammatory and immunomodulatory properties being an active a...

Introduction: The superfamily of transient receptor potential (TRP) cation channels is involved in nociception. Members of this family, such as the vanilloid receptor type 1 (TRPV1) channel, are activated by a wide range of stimuli including heat (⟩43°C), low pH (⟨6.5), hypoxia, and hypertonicity. Here we report TRPV1 expression in rabbit and huma...

Purpose: Nerve growth factor (NGF) is a neuropeptide essential for the development, survival, growth, and differentiation of corneal cells. Its effects are mediated by both TrkA and p75 receptors. Clinically relevant use of NGF was introduced to treat neurotrophic ulcerations in patients. Herein, we examine the mechanisms by which NGF enhances epi...

To determine the effects of intravitreal atropine on scleral growth in the form-deprived chick as an experimental model of myopia. Five groups of five chicks were studied from day 0-12 post-hatching. One group remained untreated (C), and four were form-deprived by monocular light diffusers to induce myopia. Two groups (RL and A) wore diffusers for...

The performance of femtosecond (fs) laser intrastromal ablation was evaluated with backscattering-mode adaptive-optics multiphoton microscopy in ex vivo chicken corneas. The pulse energy of the fs source used for ablation was set to generate two different ablation patterns within the corneal stroma at a certain depth. Intrastromal patterns were ima...

Purpose One of the most important challenges in corneal preservation is to maintain the epithelial and endothelial integrity. In previous work (Cell Motil. Cytoskeleton 66:1087, 2009) we found that short term (1 hour) hyperpolarization of the plasma membrane potential (HPMP) produces a reorganization of the actin cytoskeleton and increases the stab...

Purpose To evaluate the reversibility of the clinical and histological changes induced in the corneas of an animal model after removing intracorneal ring segment (ICRS). Methods We performed surgery for this study in 30 eyes (15 hens) of an experimental animal model of ICRS surgery(Ferrara technique) previously described by us. The animals were ran...

Purpose To determine the effect of different growth factors during corneal stromal wound repair in vitro. Methods The effect of TGF‐β, FGFb and PDGF‐BB on proliferation, migration and differentiation was evaluated in human corneal keratocytes cultures. The same type of wound was performed in all cultures. After making wounds, keratocytes were cultu...

The objective of this work was to evaluate the potential use of less stiff materials based on acrylic copolymers of methyl methacrylate/2-ethylhexyl acrylate (MMA/EHA) as devices to correct, stabilize and improve the effect of poly(methyl methacrylate) (PMMA) intracorneal ring segments. MMA/EHA and PMMA intracorneal ring segments were surgically im...

To determine the relation between the corneal light transmission measurements and the epithelial surface properties in hen corneas after different refractive surgery techniques photorefractive keratectomy, laser in situ keratomileusis, and laser-assisted subepithelial keratomileusis, and a group with only epithelial corneal removal (deepithelializa...

Polymethylmethacrylate (PMMA) segments are normally used in additive surgery to treat both corneal ectasia post laser-assisted in situ keratomileusis and keratoconus. The aim of this work was to develop an experimental animal model to induce wound healing in the deep stroma in corneas of hens. PMMA segments were implanted in the right eyes of 40 ad...

The aim of this work is to provide experimental data for corneal transparency and scattering to help create a more complete model of corneal transparency. The scattered light in 96 healing hen corneas was measured for three wavelengths by a scatterometer constructed in the Optics Laboratory (The University of Valladolid, Spain). With the help of mi...

The wound-healing response is critical to the outcome of refractive surgery and studying wound healing contributes to an understanding of the pathophysiology of other corneal injuries. Animal models allow research to be conducted with sufficient samples and under controlled parameters. We studied the hen to determine the healing process from clinic...

The aim of this work is to analyse the simultaneous influence of test and surround luminance's on letter contrast sensitivity measurements. The final issue is to find environmental lighting conditions under which this psychophysical magnitude shows maximum invariance relative to luminance changes in the surround nearest the test. The clinical study...

Light scattering from cells: The contribution of the nucleus and the effects of proliferative status " , RESUMEN Se presenta las líneas de investigación del grupo de Óptica de la Visión de la Universidad de Valladolid. La primera de las líneas se centra en la medida de la transmitancia y difusión de los tejidos corneales, la segunda, en los cambios...

To develop an experimental animal model of laser in situ keratomileusis (LASIK) in hens. One hundred adult hens underwent a 60-microm corneal flap followed by -4 diopter excimer laser ablation. Surgical technique, clinical course, and pathology correlations are presented. Sixty percent of animals had a successful LASIK outcome according to clinical...

Photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) are frequent techniques performed to correct ametropia. Both methods have been compared in their way of healing but there is not comparison about transmittance and light scattering during this process. Scattering in corneal wound healing is due to three parameters: cellular...

In the seminiferous epithelium, both DNA synthesis and apoptosis occur at equivalent stages in various species, with apoptosis taking place mainly at the same stages as DNA replication in the second, third and fourth spermatogonial generations. As preservation of the cellular associations found at these stages may have some functional significance,...

Cytoplasmic caudal tags of maturing spermatids condense and are detached from the spermatidal cells just before the spermatids are released as spermatozoa. The detached cytoplasmic masses are termed "residual bodies." Features of residual bodies seem to be compatible with those of apoptosis and, just as occurs with apoptotic bodies, residual bodies...

Spontaneous germ cell death during spermatogenesis is an important event, and the usefulness of the seminiferous epithelium as an in vivo model to study apoptosis has been evidenced. Nevertheless, the response of the testis to apoptogenic agents has not been analyzed. This study was designed to determine germ cell sensitivity to induction of apopto...

Spermatogenesis is a highly synchronized process in which FSH and testosterone are considered the major regulators. Nevertheless, the mechanism by which these hormones act on germ cells is unclear. Cell adhesion has been proved to play an essential role in the regulation of programmed cell death in epithelial cells and it is now known that FSH and...

It has become clear in recent years that programmed cell death is regulated during development by signals from other cells. Nevertheless, compared to the 'social' control of cell proliferation, relatively little is known about the 'social' control of cell death in other systems. Since in a previous study we showed that induced germ cell apoptosis o...

This study was designed to determine the effects of short episodes of mild hypothermia on cell apoptosis in the testis of the adult rat. Apoptosis was assessed by in situ DNA 3'-end labeling in the testes from rats killed 2 hours after cooling (10 degrees C for 30 minutes), quantitated, and compared with spontaneous apoptosis found in control anima...

It is widely assumed that oestrogen administration in the male mimics hypophysectomy by suppressing gonadotrophin secretion. Nevertheless, oestradiol treatment can increase germ-cell apoptosis mainly at stages IV-X of the spermatogenic cycle, rather than at stage VII when apoptotic germ-cell death is mainly triggered by gonadotrophin withdrawal cau...

The involvement of apoptosis in germ cell degeneration in the adult rat testis after gonadotrophin suppression has recently been shown in several studies, which have focused on the localization of apoptotic cells to the stages of the spermatogenic cycle. However, the precise germ cell types and maturing steps at which apoptosis is elicited remain c...

The analysis of the morphological response of the seminiferous epithelium to hormone suppression after hypophysectomy has been widely used in the study of spermatogenesis. Unlike hypophysectomy, which causes a sharp fall in gonadotropin levels, oestradiol treatment, although mimicking its effects, leads to a partial and progressive hormone suppress...

Spontaneous germ cell degeneration occurs in the testis of the adult rat. Accumulating data supports the idea that this degeneration takes place via apoptosis. We have determined that morphology, acridine orange staining and ultrastructural features of these cell deaths clearly take the form of apoptosis. Furthermore, with acridine orange staining...

The effects of unilateral olfactory deprivation on the glial population during the olfactory bulb development have been studied. The lack of sensory stimulation has been found to be related to an increase in gliofibrillary acid protein (GFAP) in the three layers of the deprived bulbs. This increase is due to the higher number of astrocytes in the d...