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1.
Public Health Action ; 13(2): 34-36, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37359061

RESUMEN

Undernutrition is the leading risk factor for TB infection and death in India. We undertook a micro-costing analysis of a nutritional intervention for household contacts of people living with TB in Puducherry, India. We found that the total 6-month food cost for a family of four was USD4/day. We also identified several alternative regimens and cost-lowering strategies to encourage wider adoption of nutritional supplementation as a public health tool.


La sous-nutrition est le principal facteur de risque d'infection et de décès dus à la TB en Inde. Nous avons entrepris une analyse de micro-coût d'une intervention nutritionnelle destinée aux contacts familiaux des personnes atteintes de la TB à Puducherry, en Inde. Nous avons constaté que le coût total de la nourriture pendant 6 mois pour une famille de quatre personnes était de 4 USD par jour. Nous avons également identifié plusieurs régimes alternatifs et stratégies de réduction des coûts pour encourager une adoption plus large de la supplémentation nutritionnelle en tant qu'outil de santé publique.

2.
Public Health Action ; 10(3): 110-117, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-33134125

RESUMEN

SETTING: India's National Tuberculosis Elimination Programme (NTEP) covers diagnostic and therapeutic costs of TB treatment. However, persons living with TB (PLWTB) continue to experience financial distress due to direct costs (payment for testing, treatment, travel, hospitalization, and nutritional supplements) and indirect costs (lost wages, loan interest, and cost of domestic helpers). OBJECTIVE: To analyze the magnitude and pattern of TB-related costs from the perspective of Indian PLWTB. DESIGN: We identified relevant articles using key search terms ('tuberculosis,' 'India,' 'cost,' 'expenditures,' 'financing,' 'catastrophic' and 'out of pocket') and calculated variance-weighted mean costs. RESULTS: Indian patients incur substantial direct costs (mean: US$46.8). Mean indirect costs (US$666.6) constitute 93.4% of the net costs. Mean direct costs before diagnosis can be up to four-fold that of costs during treatment. Treatment in the private sector can result in costs up to six-fold higher than in government facilities. As many as one in three PLWTB in India experience catastrophic costs. CONCLUSION: PLWTB in India face high direct and indirect costs. Priority interventions to realize India's goal of eliminating catastrophic costs from TB include decreasing diagnostic delays through active case finding, reducing the need for travel, improving awareness and perception of NTEP services, and ensuring sufficient reimbursement for inpatient TB care.

4.
P R Health Sci J ; 38(3): 148-155, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31536627

RESUMEN

OBJECTIVE: To perform an epidemiologic profile of pancreatic cancer (PC) in Puerto Rico (PR) with data gathered from 2001 to 2015. METHODS: Using data from the PR Central Cancer Registry we estimated incidence and mortality rates and trends of PC in PR, and performed survival analyses. We also compared the age-standardized incidence and mortality rates of PC in people in PR with those of Hispanics, non-Hispanic whites, and non Hispanic blacks in the United States (US). RESULTS: From 2011 to 2015, 7.8 per 100,000 persons were diagnosed with PC in PR; higher rates were observed in men than in women (9.2 vs. 6.7 per 100,000, respectively) and in persons 65 years old and older (42.7 per 100,000 persons). For the same period, 6.7 per 100,000 persons died from PC; men and persons 65 years and older had higher mortality rates. Incidence and mortality trends of PC in PR increased from 2001-2015 (annual percent change [APC] = 3.8% and 1.9%, respectively (p<0.05). Lower risk of being diagnosed with and dying from PC was seen in PR than in members of several racial/ethnic groups in the US. The median survival time for PC cases diagnosed in PR during the period of 2008 to 2012 was 5.3 months. CONCLUSION: We observed increasing mortality rates and low survival in PC patients in PR. Research on access and response to treatment is needed to elucidate the reasons for the observed results and have a positive impact on PC burden and survival.


Asunto(s)
Negro o Afroamericano/estadística & datos numéricos , Hispánicos o Latinos/estadística & datos numéricos , Neoplasias Pancreáticas/epidemiología , Población Blanca/estadística & datos numéricos , Anciano , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Puerto Rico/epidemiología , Sistema de Registros , Tasa de Supervivencia
8.
Artículo en Inglés | MEDLINE | ID: mdl-34368452

RESUMEN

BACKGROUND & OBJECTIVE: Pancreatic cancer is an uncommon type of cancer worldwide. Nonetheless, even with early diagnosis, mortality rates are high. This study aims to perform an epidemiologic profile of pancreatic cancer in Puerto Rico (PR) from 1987-2010. METHODS: Using data from the Puerto Rico Central Cancer Registry, age-standardized incidence and mortality rates of pancreatic cancer in PR were compared with Hispanics, non-Hispanic Whites, and non-Hispanic Blacks in the United States of America (USA). Incidence and mortality trends of pancreatic cancer were estimated, and survival analyses were also performed. RESULTS: In 2005-2010, 5.8 per 100,000 persons were diagnosed with pancreatic cancer in PR and mortality rates were similar. Pancreatic cancer was more frequent in men (6.5 per 100,000 men) than women (5.2 per 100,000 women), and in persons older than 65 years (32.0 per 100,000 persons). Moreover, the median survival for the people diagnosed with pancreatic cancer in PR during 2006-2007 was 4 months and at the end of the third year after diagnosis, only 13% of the patients survived. Incidence trends of pancreatic cancer showed an increase for men (APC=13.0%, p<0.05) from 2006 to 2010, but not for women (APC=-0.4, p>0.05). However, mortality trends showed a slight decrease for men (APC=-1.0%, p<0.05), but not for women (APC=1.4, p>0.05) in the period of 1987 to 2010. Meanwhile, Puerto Ricans in comparison to other racial/ethnic groups living in the USA showed a lower risk for being diagnosed and of dying from pancreatic cancer. CONCLUSION: Our results highlight the need for additional research in pancreatic cancer, in order to have an impact in disease survival in PR.

9.
Biol Psychiatry ; 47(12): 1087-90, 2000 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10862809

RESUMEN

BACKGROUND: Previous studies have shown that major depression is frequently accompanied by hypercortisolemia. There is some evidence suggesting that an increase in the glucocorticoid levels may make hippocampal cells more vulnerable to insults caused by hypoxia, hypoglycemia, or excitatory neurotransmitters. Using magnetic resonance imaging (MRI), the hippocampi of patients with major depression were measured and compared with values observed in control subjects. METHODS: Thirty-eight patients with primary unipolar major depression were recruited. Twenty control subjects were matched for age, gender, and years of education. The hippocampal volume was measured from coronal MRI scans in all of the subjects. Patients were also grouped and compared as responders and nonresponders to treatment with fluoxetine of 20 mg/day, for 8 weeks. Hamilton Depression Rating Scale (HDRS) was used to determine the severity of depression. RESULTS: No significant differences were observed between the hippocampal volumes of patients with major depression and control subjects; however, a significant correlation was observed between the left hippocampal volume of men and their HDRS baseline values. In addition, female responders had a statistically significant higher mean right hippocampal volume than nonresponders. CONCLUSIONS: The results of our study indicate no reduction in the volume of the hippocampus in patients with major depression. Nonetheless, the results do suggest that the effects of disease severity, gender, and treatment response may influence hippocampal volume.


Asunto(s)
Trastorno Depresivo/patología , Hipocampo/patología , Adulto , Antidepresivos de Segunda Generación/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Trastorno Depresivo/psicología , Resistencia a Medicamentos , Femenino , Fluoxetina/uso terapéutico , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Escalas de Valoración Psiquiátrica , Caracteres Sexuales
10.
Am J Psychiatry ; 158(6): 952-4, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11384906

RESUMEN

OBJECTIVE: Previous imaging studies have described focal cortical changes in schizophrenia, with predominant findings of abnormalities in the temporal and frontal regions. The current study hypothesized that cerebellar regions involved in feedback and feed-forward loops with cortical regions affected in schizophrenia would also demonstrate structural changes. METHOD: Using magnetic resonance imaging, the authors measured the volume of individual cerebellar lobules in 19 patients with schizophrenia and 19 healthy comparison subjects. RESULTS: The inferior vermis was significantly smaller in the schizophrenic group than in the comparison group. Patients with schizophrenia also demonstrated a significantly smaller cerebellar asymmetry than the comparison subjects. CONCLUSIONS: The authors hypothesize that these morphometric changes may be developmental in origin and possibly related to cortical abnormalities.


Asunto(s)
Cerebelo/anatomía & histología , Imagen por Resonancia Magnética/estadística & datos numéricos , Esquizofrenia/diagnóstico , Adulto , Cerebelo/fisiopatología , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Esquizofrenia/fisiopatología
11.
J Histochem Cytochem ; 38(5): 675-84, 1990 May.
Artículo en Inglés | MEDLINE | ID: mdl-2332625

RESUMEN

We used a staining procedure specific for sulfated glycosaminoglycans, cuprolinic blue dye (CBD), and immunohistochemical techniques to determine the histological distribution and ultrastructural organization of proteoglycans in developing rabbit cornea. We found several types of CBD-stained structures located throughout the corneal stroma, indicative of the distribution and perhaps the chemical heterogeneity of proteoglycans in this tissue. Keratan sulfate-specific immunohistochemical evidence supports our cytochemical findings. Our results suggest that low-sulfated keratan sulfate proteoglycans are found throughout most of the developing stroma, with the exception of the posterior margin of this tissue. Highly sulfated keratan sulfate proteoglycans in young fetal corneas, initially restricted to the subepithelial stroma, progressively extend to deeper portions of the stroma with development. Dermatan sulfate proteoglycans are located throughout the stroma, including the posterior margin. Invoking a recently published "oxygen-lack hypothesis" and correlating the tissue location of proteoglycans with the source of oxygen, we hypothesize that the distribution of proteoglycans in the developing rabbit cornea is related to the selective synthesis of keratan sulfate glycosaminoglycans under hypoxic conditions.


Asunto(s)
Córnea/metabolismo , Proteoglicanos/metabolismo , Animales , Animales Recién Nacidos/metabolismo , Colorantes , Córnea/crecimiento & desarrollo , Córnea/ultraestructura , Feto/metabolismo , Inmunohistoquímica , Indoles , Microscopía Electrónica , Compuestos Organometálicos , Conejos , Distribución Tisular
12.
J Histochem Cytochem ; 41(10): 1447-57, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8245404

RESUMEN

Keratan sulfate proteoglycan (KSPG) and dermatan sulfate proteoglycan (DSPG) are associated with collagen fibrils in adult rabbit cornea. Because certain cytochemical data suggested that proteoglycans are associated with type VI collagen in the fetal rabbit cornea, we developed polyclonal antibodies specific to the core proteins of rabbit corneal KSPG (lumican and/or fibromodulin) and DSPG (decorin and/or biglycan) and used the antibodies as immunocytochemical probes to determine proteoglycan ultrastructural location. Immunogold particles were associated with Type VI collagen filaments but not with collagen fibrils in fetal and neonate rabbit cornea. Association of corneal KSPG and DSPG with Type VI collagen was immunocytochemically confirmed with monoclonal antibodies to low-sulfated keratan sulfate glycosaminoglycan (GAG) and chondroitin-4-sulfate GAG of DSPG. The monospecificity of the polyclonal and monoclonal antibodies and exclusive binding of antibodies to Type VI collagen filaments, together with previous chemical identification of low-sulfated KSPG and DSPG in developing rabbit cornea, support our contention that corneal proteoglycans in developing rabbit cornea are associated with Type VI collagen.


Asunto(s)
Proteoglicanos Tipo Condroitín Sulfato/análisis , Colágeno/análisis , Córnea/embriología , Dermatán Sulfato/análisis , Sulfato de Queratano/análisis , Animales , Anticuerpos Monoclonales , Western Blotting , Condroitín Liasas/metabolismo , Córnea/química , Córnea/ultraestructura , Electroforesis en Gel de Poliacrilamida , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Lumican , Conejos
13.
Invest Ophthalmol Vis Sci ; 36(1): 206-15, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7822148

RESUMEN

PURPOSE: To develop molecular probes and to identify the cell types responsible for decorin synthesis in healing cornea. METHODS: Adult rabbit cornea and rabbit corneal stromal cell (keratocyte) culture cDNA libraries were constructed. The libraries were screened with commercially available human cDNA and oligonucleotide probes. Positive clones were sequenced to obtain a full length rabbit decorin cDNA. Synthetic oligonucleotides for rabbit decorin were chosen as probes for Northern blot analysis and in situ hybridization of healing rabbit corneas. RESULTS: The cDNA sequences of the positive clones from the two libraries were identical in areas of overlap. The combined cDNA sequence indicated a 1.5-kb length with a complete open reading frame for decorin. The cDNA and deduced amino acid sequences are 90% and 88% identical, respectively, to previously reported human fibroblast and bovine bone decorin sequences. A hypervariable region near the N-terminal has little homology to decorins of other species or other rabbit protein. Northern blot analysis detected a 2.0-kb and a 2.3-kb band in mRNA from rabbit keratocyte cultures. Decorin mRNA was detected in keratocytes of normal and healing rabbit corneas by in situ hybridization. Label in the healing tissue was markedly increased above normal. Normal endothelium and epithelium in normal and healing cornea failed to show label. CONCLUSIONS: Decorin mRNA from normal adult rabbit cornea is identical to decorin mRNA from keratocytes in culture and is highly homologous to decorin from other animal species. In situ hybridization indicated an upregulation of decorin message in cells adjacent to and within the healing tissue. Both stroma-derived and endothelium-derived cells in the wound synthesize message for decorin.


Asunto(s)
Córnea/química , Proteoglicanos/análisis , Proteoglicanos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Células Cultivadas , Clonación Molecular , Córnea/citología , Lesiones de la Cornea , ADN/análisis , Decorina , Proteínas de la Matriz Extracelular , Biblioteca de Genes , Hibridación in Situ , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , ARN Mensajero/análisis , Conejos , Regulación hacia Arriba , Cicatrización de Heridas
14.
Invest Ophthalmol Vis Sci ; 26(6): 838-48, 1985 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-4008194

RESUMEN

The authors investigated the effects of calmodulin inhibitors, trifluoperazine (10-20 microM) and W-7 (25-50 microM), and of cytochalasin B (5 micrograms/ml) on the F-actin distribution, surface morphology, and migration of rat and rabbit corneal epithelial cells in tissue culture. In the rat, actively migrating cells have abundant F-actin-containing stress fibers and numerous cytoplasmic extensions of the plasmalemma. These features, and ultimately cell migration, are inhibited by calmodulin inhibitors and cytochalasin B. In the rabbit, migrating cells are devoid of stress fibers and cytoplasmic extensions. Cell migration is not inhibited by calmodulin inhibitors but is arrested by cytochalasin B. The cell-to-substrate adhesion is reduced by calmodulin inhibitors in both rat and rabbit. These findings corroborate our earlier observations in organ culture studies and support the view that corneal epithelial cell migration is calmodulin-dependent in the rat, while it is not in the rabbit. The complete blockage of migration in both species by cytochalasin B suggests that actin polymerization is critical for corneal epithelial locomotion in both species.


Asunto(s)
Actinas/fisiología , Calmodulina/fisiología , Córnea/fisiología , Cicatrización de Heridas , Actinas/antagonistas & inhibidores , Animales , Calmodulina/antagonistas & inhibidores , Movimiento Celular , Córnea/efectos de los fármacos , Córnea/ultraestructura , Citocalasina B/farmacología , Epitelio/efectos de los fármacos , Epitelio/fisiología , Epitelio/ultraestructura , Masculino , Conejos , Ratas , Ratas Endogámicas , Especificidad de la Especie , Sulfonamidas/farmacología , Trifluoperazina/farmacología , Cicatrización de Heridas/efectos de los fármacos
15.
Invest Ophthalmol Vis Sci ; 29(5): 760-6, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3130320

RESUMEN

Normal adult rabbit corneas were digested with 5% pepsin and their collagens extracted with acetic acid. Collagen extracts were fractionated by differential salt precipitation. The 2.5 M NaCl fraction was then redissolved with tris buffer and precipitated with sodium acetate. The precipitate contained a high-molecular-weight disulfide-bonded aggregate which, upon reduction with mercaptoethanol, was converted into three distinct polypeptides having molecular weights between 45 and 66 Kd. These physical characteristics, together with the susceptibility of these polypeptides to collagenase and their amino acid composition, identified the high molecular weight aggregate as type VI collagen. Corneas from neonate rabbits and adult corneas containing 2-week-old scars were organ cultured in the presence of [14C] glycine to incorporate radiolabel into collagen. Tissues were digested with 0.02% pepsin and their collagens extracted with formic acid. The total radioactivity of the extracts and tissue residues was determined before the collagens were separated by SDS-polyacrylamide slab gel electrophoresis. Radioactive collagen polypeptides bands were then stained with Coomassie blue, processed for fluorography, and analyzed by densitometry. The results show that: (1) type VI collagen is synthesized by neonate corneas and healing adult corneas; (2) it is not readily solubilized from either corneal tissue by 0.02% pepsin digestion and formic acid extraction; and (3) the proportion of type VI collagen deposited in scar tissue is markedly lower than that found in neonate corneas.


Asunto(s)
Colágeno/análisis , Córnea/análisis , Aminoácidos/análisis , Animales , Radioisótopos de Carbono/metabolismo , Cicatriz/metabolismo , Colágeno/biosíntesis , Colágeno/clasificación , Córnea/citología , Córnea/metabolismo , Electroforesis en Gel de Poliacrilamida , Glicina/metabolismo , Peso Molecular , Técnicas de Cultivo de Órganos , Pepsina A/metabolismo , Conejos , Cicatrización de Heridas
16.
Invest Ophthalmol Vis Sci ; 39(1): 36-44, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9430543

RESUMEN

PURPOSE: Type VI and XII collagens and beta ig, major components of the interfibrillar matrix, may maintain proper spacing among collagen fibrils, necessary for corneal transparency. During normal corneal stroma development and healing, changes in mRNA levels of these proteins were measured to determine whether differences in steady state levels are indicative of the unique structure produced by each corneal tissue. METHODS: A full-thickness excision wound was made in each cornea of six adult rabbits and allowed to heal for 1, 2, or 4 weeks. Scar tissue from two rabbits (four scars) were used from each time period and processed for RNA extraction. Total RNA from 23-day-old fetal rabbit corneas (equivalent to approximately 1 week of stromal development) and 8-day-old neonate corneas (equivalent to approximately 3.5 weeks of stromal development) was also extracted. Relative quantities of alpha1(VI) collagen, alpha1(XII) collagen, beta ig, and beta-actin mRNAs were determined by competitive reverse transcriptase-polymerase chain reaction. Glyceraldehyde-3-phosphate dehydrogenase was used as a housekeeping gene. RESULTS: Increased mRNA levels for alpha1(VI) and alpha1(XII) collagens, beta ig, and beta-actin were seen during the first 2 weeks of healing and were followed by a decrease in 4-week-old scars. Similar increases were seen in fetal corneas with a further increase in the neonate. Differences in the beta ig mRNA levels relative to that of alpha1(XII) collagen in fetal stroma and in comparison with 1-week-old wounds suggest a higher production of beta ig in early healing tissue. CONCLUSIONS: Alterations of mRNA levels during healing and development are consistent with the cellular events and deposition of extracellular matrices in these corneal tissues. Assuming that extracellular matrix protein production is regulated at the transcriptional level, relative changes in beta ig and collagen mRNA levels reflect differences in protein deposition in early fetal and healing tissues. This is consistent with differences in the organization of the interfibrillar matrices of these tissues and their transparency.


Asunto(s)
Colágeno/metabolismo , Córnea/metabolismo , Proteínas de la Matriz Extracelular , Proteínas de Neoplasias/metabolismo , ARN Mensajero/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Cicatrización de Heridas , Actinas/genética , Actinas/metabolismo , Animales , Colágeno/genética , Córnea/embriología , Córnea/crecimiento & desarrollo , Lesiones de la Cornea , Sustancia Propia/crecimiento & desarrollo , Sustancia Propia/metabolismo , Cartilla de ADN/química , Desarrollo Embrionario y Fetal , Proteínas de Neoplasias/genética , Reacción en Cadena de la Polimerasa , ARN/aislamiento & purificación , ADN Polimerasa Dirigida por ARN , Conejos , Factor de Crecimiento Transformador beta/genética
17.
Invest Ophthalmol Vis Sci ; 23(5): 660-5, 1982 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7129810

RESUMEN

Linear nonperforating incisions were made in the corneas of 2-week-old and 2-year-old rabbits. The resulting wounds were examined by light microscopy and transmission and scanning electron microscopy. A corneal incision of a 2-week-old rabbit produced a wide gaping wound caused by retraction of the cut stromal lamellae away from the incision. The wound became wider with time as the developing eye enlarged and the cut lamellae retracted further. Polymorphonuclear leukocytes, presumably from the tear film, penetrating into the wound area before it was covered over by the sliding epithelium. Most of the leukocytes disappeared by 3 days after wounding. Three to six layers of fibroblasts appeared beneath the epithelial plug. The tissue eventually rebuilt approximately one third of the corneal depth lost to the wound. The stroma of the wounded region did not return to its normal width, but the epithelium was thicker than that of the unwounded cornea. An incision in a 2-year-old rabbit cornea produced a narrow V-shaped wound that did not change shape with time. This wound was repaired by fibroblasts resulting in collagenous repair tissue being the same depth as the normal stroma. There appears to be no evidence for wide gaping wounds in humans in the literature, as was found in this study in rabbits.


Asunto(s)
Lesiones de la Cornea , Cicatrización de Heridas , Factores de Edad , Animales , Córnea/cirugía , Conejos
18.
Invest Ophthalmol Vis Sci ; 31(9): 1789-98, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2120145

RESUMEN

Ultrastructural localization of proteoglycans (PGs) in 1-week- to 2-year-old scar was determined by staining with cuprolinic blue dye (CBD) after specific enzymatic digestion of keratan sulfate (KS) glycosaminoglycans (GAGs) or chondroitin sulfate glycosaminoglycans (CSs). High critical electrolyte conditions were maintained for CBD-staining, specific for high-sulfated GAGs. Although KS was detected in the 1-week-old wound, no CBD-stained KS was seen in the anterior stroma adjacent to the wound. The CS was present throughout the 1-week-old wound and adjacent stroma, and PGs were biosynthetically 35SO4-labeled in normal stroma. Subsequently, radioactivity from labeled PGs in normal stroma adjacent to the wound moved into scar tissue during healing. Marked sensitivity of PGs to Chondroitinase ABC indicated an abundance of CS in 2-week-old scars. Punctate CBD-staining and immunohistochemical evidence suggested chemically altered KS is present in the 2-week-old anterior scar. The pattern of CBD-staining in 1- and 2-week scars, after chondroitinase treatment, suggested KS in the younger scar is similar to adult high-sulfated GAG, whereas KS in the 2-week scar contains primarily newly synthesized low-sulfated KS. The latter is consistent with previous immunochemical and biochemical analyses. Cytochemical and immunohistochemical evidence indicated that KS is not present in the 2-week-old posterior scar. By the week 8 of healing, CBD-stained KS was present throughout most of the scar, except along the posterior margin, consistent with earlier stages of healing. The CBD-stained structures in the first 8 weeks of healing were reminiscent of stained GAGs in normal developing cornea. This fetal-like CBD-staining pattern seen in scar, however, changed to that of the normal adult by the 2nd year of healing. The significance of these observations relate to our contention that healing adult cornea recapitulates some ontogenetic events of the normal cornea, and that the nonuniform distribution and chemical properties of GAGs in scar tissue are a function of the movement of existing proteoglycans and de novo synthesis of altered macromolecules.


Asunto(s)
Cicatriz/metabolismo , Córnea/metabolismo , Proteoglicanos/metabolismo , Animales , Anticuerpos Monoclonales , Sulfatos de Condroitina/metabolismo , Córnea/ultraestructura , Glicosaminoglicanos/metabolismo , Inmunohistoquímica , Indoles , Sulfato de Queratano/metabolismo , Compuestos Organometálicos , Conejos , Cicatrización de Heridas
19.
Invest Ophthalmol Vis Sci ; 31(6): 1096-102, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2191932

RESUMEN

We have localized type VI collagen in normal developing and corneal scar tissue. Indirect immunofluorescence showed that type VI collagen was distributed throughout the normal stroma and most of the scar. No fluorescence was detected along the posterior margin of the scar and in a retrocorneal membrane continuous with the scar. Since the corneal endothelium in rabbits contributes to the formation of scar tissue and retrocorneal membrane, our observations suggest that the endothelium does not synthesize type VI collagen. Indirect immunoelectron microscopy showed that type VI collagen was located abundantly between collagen fibrils as fine filamentous structures containing beads with a periodicity of 100 nm, consistent with published observations of other tissues. Because these filaments are more prominent when stained with ruthenium red, and predigestion of tissue with Chondroitinase ABC enhances binding of monoclonal antibody to type VI collagen, proteoglycans probably are associated with this collagen in the cornea. Ultrastructural observations supported by previous biochemical analyses show that the proportion of type VI collagen to fibrillar collagen is smaller in scar tissue compared with fetal cornea. The abundance of type VI collagen and its distribution and association with proteoglycans in rabbit corneal tissues suggest that this macromolecule plays a role in the tensile strength and transparency of the stroma.


Asunto(s)
Colágeno/análisis , Córnea/embriología , Cicatrización de Heridas , Animales , Anticuerpos Monoclonales , Cicatriz/metabolismo , Colágeno/metabolismo , Córnea/análisis , Córnea/crecimiento & desarrollo , Córnea/ultraestructura , Sustancia Propia/análisis , Sustancia Propia/embriología , Sustancia Propia/crecimiento & desarrollo , Sustancia Propia/ultraestructura , Lámina Limitante Posterior/análisis , Lámina Limitante Posterior/ultraestructura , Epitelio/análisis , Epitelio/ultraestructura , Femenino , Técnica del Anticuerpo Fluorescente , Conejos
20.
Invest Ophthalmol Vis Sci ; 24(5): 543-56, 1983 May.
Artículo en Inglés | MEDLINE | ID: mdl-6841000

RESUMEN

Corneas of fetal and young albino rabbits were examined by light and transmission electron microscopy. In addition, DNA and hydroxyproline content were measured in developing stroma. The results were compared with similar data from healing corneas in adult rabbits and from developing corneas of other animal species. In the fetal rabbit, the prospective corneal stroma region contains an unorganized, sparse extracellular matrix until about the 13th day of gestation, when mesenchymal cells and capillaries from the hyaloid vessels move in to form the vascular pupillary membrane, endothelium, and stroma. Stromal growth is due to alteration in the density and morphology of the cell population early in development, along with a sequential thickening and thinning of the whole stroma. These events are similar to those reported in primates, but differ markedly from those reported in avian species. Normal developing cornea and healing adult cornea both involve migration of stomal fibroblasts and deposition of extracellular matrix. Stromal fibroblasts in the rabbit fetus are oriented with their long axis parallel to the corneal surface early in development compared with randomly oriented fibroblasts in the early healing wound of adult rabbit corneas. Although collagen and cell number progressively increase throughout the developmental periods studied, the ratio of cells to collagen is high initially but decreases with development. In contrast, the proportion of cells to collagen in the young scar tissue of adult cornea is low initially, indicating a marked deposition of collagen in comparison to that in the early normal developing stroma. The results suggest that the healing tissue differs from the normal fetal stroma in its coordination of cell population growth with collagen deposition and cellular organization.


Asunto(s)
Córnea/ultraestructura , Animales , Animales Recién Nacidos , Colágeno/análisis , Córnea/análisis , Córnea/embriología , ADN/análisis , Hidroxiprolina/análisis , Conejos
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