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Purpose of the studies was to develop a more robust technique to determine retinal mean transit time in healthy and in glaucoma eyes and to evaluate the circulation of the optic nerve head in glaucoma patients. The retinal mean transit time impulse-response method was evaluated in human healthy eyes and normal values and reproducibility were tested. Fluorescein and indocyanine green angiographies were recorded and the pictures were analyzed to obtain retinal mean transit time and to evaluate the proportion of low-fluorescent pixels of the optic nerve head in the glaucoma patients. Visual field defects were correlated to loss of neuroretinal rim area. A disturbed circulation was observed in the glaucoma patients, whether primary or secondary to loss of nerve fibre tissue can not be determined from these studies.

<p>Corneal dystrophies are commonly referred to as an congenital condition. Surgical complications are usually worse then the primary dysfunction and patients need to go through large surgical process. Only 25 % of the patients reach driving licence vision after a surgery. The aim of this study was to investigate if the application of human embryonic stem cells (hESc) could replace epithelial cells of the human cornea. Corneal markers such as cytokeratins CK3, CK15, CK19 and Pax - 6 were analysed by immunohistochemistry. HES - Cellect was used as indication of  stem cell potential of the transplanted cells. hESc transplanted onto the cornea could be seen to attach and expand dominantly  towards Bowman’s membrane. Human embryonic stem cells in culture were relatively positive for markers, contradictionally stem cells  in the epithelial trails lost their stem differentiation  potential  and appeared to be negative for all markers used in these trails. Optimization of stem cells differentiation into epithelial which may in the future may gives us the ability to perform clinical applications with successful outcome.</p>

Corneal dystrophies are commonly referred to as an congenital condition. Surgical complications are usually worse then the primary dysfunction and patients need to go through large surgical process. Only 25 % of the patients reach driving licence vision after a surgery. The aim of this study was to investigate if the application of human embryonic stem cells (hESc) could replace epithelial cells of the human cornea. Corneal markers such as cytokeratins CK3, CK15, CK19 and Pax - 6 were analysed by immunohistochemistry. HES - Cellect was used as indication of  stem cell potential of the transplanted cells. hESc transplanted onto the cornea could be seen to attach and expand dominantly  towards Bowman’s membrane. Human embryonic stem cells in culture were relatively positive for markers, contradictionally stem cells  in the epithelial trails lost their stem differentiation  potential  and appeared to be negative for all markers used in these trails. Optimization of stem cells differentiation into epithelial which may in the future may gives us the ability to perform clinical applications with successful outcome.

Introduction: The extraocular muscles (EOMs) are considered a separate class of skeletal muscle, allotype. Myosin is the major contractile protein in muscle. The myosin heavy chain (MyHC) isoforms are the best molecular markers of functional heterogeneity of muscle fibers. The relaxation rate, reflects the rate at which Ca2+ is transported back into the sarcoplasmic reticulum (SR) mostly by SR Ca2+ATPase (SERCA). Myosin binding protein C (MyBP-C), plays a physiological role in regulating contraction. The laminins (Ln) are the major non-collagenous components of the basement membrane (BM) surrounding muscle fibers and are important for muscle fiber integrity. Methods: Adult human EOMs were studied with SDS-PAGE, immunoblots and immunocytochemistry, the latter with antibodies against six MyHC, 2 SERCA, 2 MyBP-C and 8 laminin chain isoforms. The capillary density was also determined. Results: Most fibers contained a mixture of MyHC isoforms. Three major groups of fibers could be distinguished. Fast fibers that stained with anti-MyHCIIa, slow fibers that stained with anti-MyHCI and MyHCeompos/MyHCIIaneg-fibers that stained with neither of these antibodies but with anti-MyHCI+IIa+eom and anti-MyHCeom. A majority of the fibers contained both SERCA1 and 2 whereas 1% were unstained with both antibodies. Biochemically SERCA2 was more abundant than SERCA1. MyBP-Cfast was not present in the EOMs and MyBP-Cslow was only detected immunocytochemically. The extrasynaptical BM of the EOM muscle fibers contained Lna2, b1, b2, g1, a4 and a5 chains. The capillary density in the EOMs was very high (1050 +/-190 capillaries/mm2) and significantly (p&lt;0.05) higher in the orbital than in the global layer. Conclusions: The co-existence of complex mixtures of several crucial protein isoforms provide the human EOMs with a unique molecular portfolio that a) allows a highly specific fine-tuning regime of contraction and relaxation, and b) imparts structural properties that are likely to contribute to protection against certain neuromuscular diseases.

Made available in DSpace on 2016-08-10T10:39:27Z (GMT). No. of bitstreams: 1 Francisco Weliton Rodrigues.pdf: 26774271 bytes, checksum: c81af1f8ff9812886fda32632000dc44 (MD5) Previous issue date: 2008-09-29 / Pterygium is a disease of unknown origin and pathogenesis that can be vision threatening. Several researchers believe that pterygium is UV-related and that abnormal expression of p53 protein and infection with human papillomavirus (HPV) are risk factors for pterygium, but their experiments have been inconclusive. We investigated its relation with p53 protein expression, p53 gene codon 72 polymorphism and infection with HPV DNA. Pterygial samples were obtained from 36 patients; 21 normal conjunctival samples were used as controls. Expression of p53 protein was studied by Immunohistochemistry, using the antibody DO-7. Analysis for the p53 genotype was made with PCR, using specific primers for the arginine and proline alleles, and an analysis for HPV was made of the pterygium patients and control group. Fourteen of the 36 pterygia specimens were positive for abnormal p53 expression. Thirty one of the patients were heterozygotic and three were homozygotic for the proline allele; two were homozygotic for the arginine allele; in the control group 12 of 21 were heterozygotic and seven of these 21 were homozygotic for the proline allele; two were homozygotic for the arginine allele. Twenty-one of the pterygia patients were positive for HPV; HPV type 1 was found in nine of these, type 2 in seven and both types in five. Only two of the 21 controls had HPV; both had type 16. We suggest that abnormal expression of p53, p53 codon 72 polymorphisms and HPV DNA are required cofactors for the development of pterygium. / O pterígio é uma doença de origem e patogênese desconhecida que pode comprometer a visão. Vários pesquisadores acreditam que o pterígio está relacionado à luz UV e a expressão anormal da proteína p53, além da presença do papilomavírus humano (HPV), como fatores de risco para o seu desenvolvimento, mas os resultados são inconclusivos. Investigamos a expressão da proteína p53, o polimorfismo do codon 72 do gene TP53 e a presença do HPV. Amostras de pterígio foram obtidas de 36 pacientes e 21 escleras normais formaram o grupo controle. A expressão de p53 foi analisada por imunohistoquímica usando anticorpo DO-7. Análise do genótipo de p53 foi realizada por PCR com primers específicos para os alelos arginina e prolina e a presença do HPV foi analisada nos dois grupos. Quatorze amostras de pterígio (39%) foram positivas para expressão anormal de p53. O polimorfismo foi observado em 31 (86%) amostras heterozigotas, 03 (8%) homozigotas para prolina e 02 (6%) homozigotas para arginina, enquanto que no grupo controle foi observado 12 (57%) amostras heterozigotas, 07 (33%) homozigotas para prolina e 02 (10%) homozigotas para arginina. 21 pterígios (59%) foram positivos para HPV e o tipo 01 foi encontrado em 43% (9/21), tipo 02 em 34% (7/21) e os dois tipos simultaneamente em 23% (5/21) amostras do gruppo pterígio. O grupo controle mostrou 9.5% (2/21) amostras positivas para HPV e o tipo 16 nas duas amostras. Nossos dados sugerem que a expressão anormal de p53, o polimorfismo do codon 72 e a presença do HPV podem estar relacionados com o desenvolvimento do pterígio.

<p>Two different principles were studied. 1st - statistical analysis techniques were used to obtain medical results from a patient population. 2nd - the patient population was used to study the statistical analysis techniques. </p><p>Medical conclusions: latanoprost and timolol treatment showed a statistically significant and clinically useful mean IOP-reduction in a typical worldwide clinical trial population. Latanoprost reduced the IOP 1.6 mm Hg more than timolol. The IOP-reduction was maintained with timolol and slightly enforced with latanoprost up to 6 months of treatment. The mean IOP-reduction was maintained during 2 years of latanoprost treatment. The overall risk of withdrawal due to insufficient IOP-reduction with latanoprost was 8%. </p><p>The statistical methodological issues are of a general and reoccurring character in trial design of the IOP-reduction: should the statistical hypothesis testing be based on the mean intraocular pressure (IOP) or the proportion of patients who reach a specific IOP level, should the estimate of the IOP or IOP-reduction be based on single eyes, mean of bilaterally eligible and identically treated eyes or the difference between an eye with active treatment and a placebo treated contralateral eye, and is mean of replicated recordings useful? Statistical methodological conclusions: the most effective response variable varies with the selected patient population. Therefore, the trial design process should include a comparison of the variability, test power and required sample size for the possible response variables in a sample of the target population. At minimum a statistical consideration should be done.</p>

<p>In a prospective population-based study in Stockholm County, 1998-2000, the incidence of retinopathy of prematurity (ROP) was investigated and was found to be 36% in prematurely-born infants with a birth weight of ≤ 1500 grams. Compared to a study performed ten years ago, the overall incidence was unchanged, but was reduced in “mature” infants and increased in immature ones. The incidence of ROP was 25% in infants with a gestational age of ≤ 32 weeks at birth. The main risk factors for ROP were the gestational age at birth, followed by the birth weight. Current guidelines for ROP screening in Sweden were modified.</p><p>A 10-year follow-up study of the ophthalmological findings in prematurely-born children, previously included in a prospective population-based incidence study of ROP, was performed. The children were compared with full-term ones. </p><p>Prematurely-born children ran a four times higher risk of refractive errors than full-term ones. The cryotreated children had the highest risk, but those without ROP also had more refractive errors than the full-terms. Within the group of prematurely-born children, the cryotreated ones had the highest prevalence of myopia, astigmatism and anisometropia, but no difference was found regarding hypermetropia.</p><p>The visual acuity of prematurely-born children was poorer than that of the full-terms. The cryotreated children and those with neurological complications had the most marked reduction, but the children without ROP and neurological findings also had a poorer visual outcome than the full-terms. The prevalence of visual impairment was 1.8% among the prematurely-born children, and was due to ROP in half the cases and cerebral lesions in the others. </p><p>The cryotreated children had constricted peripheral visual fields compared to the untreated prematurely-born and full-term children. The central visual fields tended to be reduced in the prematurely-born children compared to the full-terms, but no difference was observed within the preterm group.</p>

Two different principles were studied. 1st - statistical analysis techniques were used to obtain medical results from a patient population. 2nd - the patient population was used to study the statistical analysis techniques. Medical conclusions: latanoprost and timolol treatment showed a statistically significant and clinically useful mean IOP-reduction in a typical worldwide clinical trial population. Latanoprost reduced the IOP 1.6 mm Hg more than timolol. The IOP-reduction was maintained with timolol and slightly enforced with latanoprost up to 6 months of treatment. The mean IOP-reduction was maintained during 2 years of latanoprost treatment. The overall risk of withdrawal due to insufficient IOP-reduction with latanoprost was 8%. The statistical methodological issues are of a general and reoccurring character in trial design of the IOP-reduction: should the statistical hypothesis testing be based on the mean intraocular pressure (IOP) or the proportion of patients who reach a specific IOP level, should the estimate of the IOP or IOP-reduction be based on single eyes, mean of bilaterally eligible and identically treated eyes or the difference between an eye with active treatment and a placebo treated contralateral eye, and is mean of replicated recordings useful? Statistical methodological conclusions: the most effective response variable varies with the selected patient population. Therefore, the trial design process should include a comparison of the variability, test power and required sample size for the possible response variables in a sample of the target population. At minimum a statistical consideration should be done.

In a prospective population-based study in Stockholm County, 1998-2000, the incidence of retinopathy of prematurity (ROP) was investigated and was found to be 36% in prematurely-born infants with a birth weight of ≤ 1500 grams. Compared to a study performed ten years ago, the overall incidence was unchanged, but was reduced in “mature” infants and increased in immature ones. The incidence of ROP was 25% in infants with a gestational age of ≤ 32 weeks at birth. The main risk factors for ROP were the gestational age at birth, followed by the birth weight. Current guidelines for ROP screening in Sweden were modified. A 10-year follow-up study of the ophthalmological findings in prematurely-born children, previously included in a prospective population-based incidence study of ROP, was performed. The children were compared with full-term ones. Prematurely-born children ran a four times higher risk of refractive errors than full-term ones. The cryotreated children had the highest risk, but those without ROP also had more refractive errors than the full-terms. Within the group of prematurely-born children, the cryotreated ones had the highest prevalence of myopia, astigmatism and anisometropia, but no difference was found regarding hypermetropia. The visual acuity of prematurely-born children was poorer than that of the full-terms. The cryotreated children and those with neurological complications had the most marked reduction, but the children without ROP and neurological findings also had a poorer visual outcome than the full-terms. The prevalence of visual impairment was 1.8% among the prematurely-born children, and was due to ROP in half the cases and cerebral lesions in the others. The cryotreated children had constricted peripheral visual fields compared to the untreated prematurely-born and full-term children. The central visual fields tended to be reduced in the prematurely-born children compared to the full-terms, but no difference was observed within the preterm group.