Massage protects skeletal muscle from injury during long-term heavy-duty exercise via integrin ß1 and laminin 2 channels of basement membrane.

BACKGROUND: Massage is widely used in exercise-induced skeletal muscle damage (EIMD). It has been proven that massage can improve the morphology and function of damaged skeletal muscle in multiple ways. However, whether massage can protect skeletal muscles from injury during long-term heavy-duty exercise has not yet been determined. METHODS: In this study, a rat model of overuse injury was established by eccentric running for 4 weeks, and pressing at constant pressure and frequency and massage were used as intervention methods to explore whether massage could protect skeletal muscle from injury through upregulating integrin and the basement membrane laminin. RESULTS: The results showed that compared with the model group, the ultrastructure of skeletal muscle in the massage group was relatively complete and clear, and the maximum isotonic and tetanic contraction forces were significantly increased (P < 0.01). In addition, in the massage group, ß1 integrin expression was significantly increased, p-FAK protein expression was decreased, and the co-localization of ß1 integrin and the basement membrane laminin 2 was significantly increased (P < 0.01). CONCLUSION: Our study shows that during long-term heavy-duty exercise, massage can enhance the cell adhesion function mediated by integrin ß1 and laminin 2 to protect skeletal muscle from injury and prevent the occurrence of overuse injury.

Fibroblastic and bone marrow-derived cellularity in the corneal stroma.

The unwounded, normal corneal stroma is a relatively simple, avascular tissue populated with quiescent keratocytes, along with corneal nerves and a few resident dendritic and monocyte/macrophage cells. In the past, the resting keratocytes were thought of as a homogenous cellular population, but recent work has shown local variations in vimentin and nestin expression, and responsiveness to transforming growth factor (TGF)-ß1. Studies have also supported there being "stromal stem cells" in localized areas. After corneal wounding, depending on the site and severity of injury, profound changes in stromal cellularity occur. Anterior or posterior injuries to the epithelium or endothelium, respectively, trigger apoptosis of adjacent keratocytes. Many contiguous keratocytes transition to keratocan-negative corneal fibroblasts that are proliferative and produce limited amounts of disorganized extracellular matrix components. Simultaneously, large numbers of bone marrow-derived cells, including monocytes, neutrophils, fibrocytes and lymphocytes, invade the stroma from the limbal blood vessels. Ongoing adequate levels of TGFß1, TGFß2 and platelet-derived growth factor (PDGF) from epithelium, tears, endothelium and aqueous humor that penetrate defective or absent epithelial barrier function (EBF) and epithelial basement membrane (EBM) and/or Descemet's basement membrane (DBM) drive corneal fibroblasts and fibrocytes to differentiate into alpha-smooth muscle actin (SMA)-positive myofibroblasts. If the EBF, EBM and/or DBM are repaired or replaced in a timely manner, typically measured in weeks, then corneal fibroblast and fibrocyte progeny, deprived of requisite levels of TGFß1 and TGFß2, undergo apoptosis or revert to their precursor cell-types. If the EBF, EBM and/or DBM are not repaired or replaced, stromal levels of TGFß1 and TGFß2 remain elevated, and mature myofibroblasts are generated from corneal fibroblasts and fibrocyte precursors that produce prodigious amounts of disordered extracellular matrix materials associated with scarring fibrosis. This fibrotic stromal matrix persists, at least until the EBF, EBM and/or DBM are regenerated or replaced, and keratocytes remove and reorganize the affected stromal matrix.

Manifestaciones oftalmológicas de la epidermólisis bullosa / Ophthalmological manifestations of epidermolysis bulosa

La epidermólisis bullosa es una genodermatosis, que comprende un grupo heterogéneo de enfermedades ampollares de la piel y las mucosas, localizadas en la membrana basal epidérmica y la capa basal del epitelio estratificado queratinizado o mucoso, con la consiguiente fragilidad de la piel y severidad variable en su presentación clínica. Con el objetivo de describir y mostrar los hallazgos oftalmológicos más comunes de esta afección, presentamos un caso cuyos síntomas iniciaron a los dos meses de edad con presencia de vesículas y ampollas localizadas en la región frontal, nasal, mejillas y caras laterales del cuello de la frente y las extremidades superiores e inferiores. Las manifestaciones oftalmológicas comenzaron a los seis meses de edad en ambos ojos con leucoma corneal cicatrizal total, simblefaron en 360º, que alcanzó región perilímbica. Todo lo anterior afectó su desarrollo visual y por consiguiente su desarrollo psicomotor. Esta afección requiere tratamiento multidisciplinario con especial atención a la superficie ocular externa para prevenir alteraciones que afecten la visión(AU)

Epidermolysis bulosa is defined as genodermatosis involving a heterogenous group of blistering diseases in the skin and the mucosas, located in the epidermal basal membrane and the basal layer of the stratified, keratinized or mucosal epithelium, with resulting fragility of the skin and variable severity in its clinical presentation. The most common eye findings of this disease were described and shown. The treatment of epidermolysis bulosa should be multidisciplinary, paying special attention to the outer ocular surface to prevent alterations that may affect the vision(AU)

Distrofia de la membrana basal epitelial / epithelial basal membrane dystrophy

La distrofia de Cogan es la distrofia corneal anterior más común, frecuente en adultos del sexo femenino, entre 40-70 años de edad. Presentamos un caso de una paciente de 50 años de edad, del sexo femenino, quien refiere visión borrosa, lagrimeo y fotofobia. Al examen de la córnea en lámpara de hendidura se observan imágenes de color grisáceo en forma de huellas dactilares y de mapa. Esta afección es causada por alteraciones de la membrana basal epitelial que provoca la separación parcial o total del epitelio corneal. Generalmente asintomática, es la causa más frecuente de erosión corneal recurrente. Las opciones terapéuticas varían desde lubricantes, soluciones hipertónicas tópicas, lentes de contacto de vendaje, desbridamiento del epitelio central, micropunciones mecánicas o diatermia y fotoqueratectomía con láser excímer.(AU)

Cogan's dystrophy is the most common anterior corneal dystrophy in adult females aged 40-70 years of age. Here is a 50 years-old female patient suffering from blurred vision, weeping eyes and photophobia. On examination, grayish images were observed in the form of fingerprints and map. This disease is caused by alterations of the epithelial basal membrane bringing about partial or total removal of the corneal epithelium. Often asymptomatic, it is the most common cause of recurrent corneal erosion. Treatment options range from lubricants, topical hypertonic solutions, bandage contact lenses, central epithelial debridement, mechanical or diathermy micropuncture and excimer laser photokeratectomy.(AU)

Manifestaciones oftalmológicas de la epidermólisis bullosa / Ophthalmological manifestations of epidermolysis bulosa

La epidermólisis bullosa es una genodermatosis, que comprende un grupo heterogéneo de enfermedades ampollares de la piel y las mucosas, localizadas en la membrana basal epidérmica y la capa basal del epitelio estratificado queratinizado o mucoso, con la consiguiente fragilidad de la piel y severidad variable en su presentación clínica. Con el objetivo de describir y mostrar los hallazgos oftalmológicos más comunes de esta afección, presentamos un caso cuyos síntomas iniciaron a los dos meses de edad con presencia de vesículas y ampollas localizadas en la región frontal, nasal, mejillas y caras laterales del cuello de la frente y las extremidades superiores e inferiores. Las manifestaciones oftalmológicas comenzaron a los seis meses de edad en ambos ojos con leucoma corneal cicatrizal total, simblefaron en 360º, que alcanzó región perilímbica. Todo lo anterior afectó su desarrollo visual y por consiguiente su desarrollo psicomotor. Esta afección requiere tratamiento multidisciplinario con especial atención a la superficie ocular externa para prevenir alteraciones que afecten la visión.

Epidermolysis bulosa is defined as genodermatosis involving a heterogenous group of blistering diseases in the skin and the mucosas, located in the epidermal basal membrane and the basal layer of the stratified, keratinized or mucosal epithelium, with resulting fragility of the skin and variable severity in its clinical presentation. The most common eye findings of this disease were described and shown. The treatment of epidermolysis bulosa should be multidisciplinary, paying special attention to the outer ocular surface to prevent alterations that may affect the vision.

Distrofia de la membrana basal epitelial / epithelial basal membrane dystrophy

La distrofia de Cogan es la distrofia corneal anterior más común, frecuente en adultos del sexo femenino, entre 40-70 años de edad. Presentamos un caso de una paciente de 50 años de edad, del sexo femenino, quien refiere visión borrosa, lagrimeo y fotofobia. Al examen de la córnea en lámpara de hendidura se observan imágenes de color grisáceo en forma de huellas dactilares y de mapa. Esta afección es causada por alteraciones de la membrana basal epitelial que provoca la separación parcial o total del epitelio corneal. Generalmente asintomática, es la causa más frecuente de erosión corneal recurrente. Las opciones terapéuticas varían desde lubricantes, soluciones hipertónicas tópicas, lentes de contacto de vendaje, desbridamiento del epitelio central, micropunciones mecánicas o diatermia y fotoqueratectomía con láser excímer.

Cogan's dystrophy is the most common anterior corneal dystrophy in adult females aged 40-70 years of age. Here is a 50 years-old female patient suffering from blurred vision, weeping eyes and photophobia. On examination, grayish images were observed in the form of fingerprints and map. This disease is caused by alterations of the epithelial basal membrane bringing about partial or total removal of the corneal epithelium. Often asymptomatic, it is the most common cause of recurrent corneal erosion. Treatment options range from lubricants, topical hypertonic solutions, bandage contact lenses, central epithelial debridement, mechanical or diathermy micropuncture and excimer laser photokeratectomy.

New insights in wound response and repair of epithelium.

Epithelial wounds usually heal relatively quickly, but repair may be impaired by environmental stressors, such as hypoxic or diabetic states, rendering patients vulnerable to a number of corneal pathologies. Though this response appears simple, at first, years of research have uncovered the complicated biochemical pathways coordinating the wound healing response. Here, we investigate signaling cascades and individual proteins involved in the corneal epithelium's self-repair. We will explore how an epithelial cell migrates across the wound bed and attaches itself to its new post-injury surroundings, including its neighboring cells and the basement membrane, through focal adhesions and hemidesmosomes. We will also discuss how the cell coordinates this motion physiologically, through calcium signaling and protein phosphorylation, focusing on the communication through purinergic, glutamatergic, and growth factor receptors. Many of these aspects reflect and can be extended to similar epithelial surfaces, and can be used to facilitate wound healing in patients with various underlying pathologies. The collective library of laboratory and clinical research done around the world has demonstrated how important precise regulation of these processes is in order for the injured corneal epithelium to properly heal.

Caso interesante de lámina amniótica / Interesting case of amniotic sheet

Antecedentes: Las anormalidades de las membranas intrauterinas amnióticas del embarazo incluye 1) bridas amnióticas, 2) adherencias intrauterinas que condicionan las sinequias y las láminas amnióticas y 3) tabiques uterinos. Son un diagnóstico frecuente en el examen ultrasonográfico rutinario en embarazadas. La lámina amniótica es una lámina de tejido aberrante visualizado dentro de la cavidad uterina, resultado de una sinequia que es rodeada por el amnios y el corion que se expande, es de naturaleza benigna, no produce restricción a la movilidad fetal ni deformidad del mismo. Caso Clínico: Paciente de 23 años de edad, con historia gineco-obstétrica de 2 gestas, el primer embarazo término en aborto, por lo que se le realizo legrado uterino instrumentado, a las 29 7/4 semanas gestacionales se detecta con ultrasonido convencional, una lámina amniótica completa a nivel del segmento inferior del útero. A las 38 semanas presenta ruptura prematura de membranas, por lo que se realiza cesárea sin complicaciones, obteniéndose recién nacido femenino con APGAR 8 y 9 a los 15 minutos respectivamente, con peso de 2945 g, sin anormalidades estructurales, además la placenta y el cordón umbilical no evidenciarón ninguna anormalidad. Conclusión: Las anormalidades de las membranas amnióticas son de reciente descripción y se desconoce su frecuencia, la lámina amniótica es más común que las bandas, la etiología no está bien establecida, pero una de las teorías más aceptada es que son consecuencia de sinequias, debido a infecciones, procedimientos quirúrgicos, instrumentación uterina, entre ellos el legrado como se presentó en este caso...

Localized bullous pemphigoid induced by photodynamic therapy.

Topical photodynamic therapy (PDT) causes localized phototoxicity and has been shown both in vitro and in humans to have immunomodulatory and immunosuppressive effects. We report a case of localized bullous pemphigoid (BP) developing after PDT. Although BP has been reported to develop following cutaneous insults such as surgery, radiotherapy, psoralen ultraviolet A (PUVA) and ultraviolet B phototherapy, PDT has not previously been reported as a trigger. Possible mechanisms include direct mechanical injury to the basement membrane and subsequent autoantibody formation, an indirect immunomodulatory effect of PDT, or most likely, precipitation of BP in individuals with pre-existing low titres of epidermal autoantibodies (so-called subclinical BP). PDT should be added to the list of possible exogenous triggers for BP and this condition should be considered if blistering develops following PDT.

E-cadherin and transglutaminase-1 epithelial barrier restoration precedes type IV collagen basement membrane reconstruction following vocal fold mucosal injury.

The vocal fold epithelium is critical to upper airway immunologic defense and water/ion transport; therefore, any form of physical trauma or insult increases the vulnerability of this structure to functional impairment and pathogen invasion/infection. In this study, we examined the reestablishment of epithelial and basement membrane barrier structures in a well-established rat model of vocal fold mucosal injury. We observed active cell recruitment culminating in peak hyperplasia at 3 days postinjury, the establishment of robust E-cadherin+ and transglutaminase-1+ biochemical barrier signals along the epithelial surface by 3 days postinjury, and the persistent absence of a type IV collagen+ basement membrane at 7 days postinjury. The distinct spatial and temporal immunoactivity of these molecules is consistent with a programmed repair process driving the restoration of vocal fold mucosal integrity and permeability. These data may inform future efforts to optimize functional mucosal recovery postinjury and avoid undesirable events such as barrier compromise or epithelial metaplasia.

Coordinated regulation of vascular Ca2+ and K+ channels by integrin signaling.

A role for integrins in mechanotransduction has been suggested because these molecules form an important mechanical link between the extracellular matrix (ECM) and the cytoskeleton. An example of mechanotransduction in blood vessels is the myogenic response--the rapid and maintained constriction of arterioles in response to pressure elevation. L-type calcium channels and large-conductance, calcium-activated potassium (BK) channels are known to play important roles in the myogenic response and in the maintenance of myogenic (pressure-induced) vascular tone. Our recent studies on isolated, cannulated arterioles and freshly-dispersed arteriolar smooth muscle cells show that both L-type calcium channels (Ca(v)1.2) and BK channels are regulated by alpha5beta1 integrin activation. Alpha5beta1 integrin interacts with the ECM protein fibronectin, which is distributed in basement membrane and interstitial matrices surrounding smooth muscle cells within the arteriolar wall. Truncation and site-directed mutagenesis strategies reveal that regulation of Ca(v)1.2 by alpha5beta1 integrin requires phosphorylation of the channel alpha1C subunit at C-terminal residues Ser-1901 and Tyr-2122. Likewise, BK channel potentiation by alpha5beta1 integrin activation requires c-Src phosphorylation of the channel alpha-subunit at residue Tyr-766. Thus, both L-type calcium channels and BK channels can be regulated coordinately through integrin-linked phosphorylation cascades involving c-Src. We propose that these two channels are under constitutive control by alpha5beta1 integrin-fibronectin interactions in the vessel wall such that the balance of their activity determines myogenic tone and the vascular response to vessel wall injury/remodeling.

Different therapy options protecting microvasculature after experimental cerebral ischaemia and reperfusion.

Recombinant tissue plasminogen activator (rt-PA) is successfully used in human stroke, but often shows serious drawbacks. To find an alternative, we hypothesised that the novel thrombolytic microplasmin would have fewer adverse effects on haemoglobin extravasation and microvascular damage compared with the effects of rt-PA and tenecteplase (TNK). A constant period of ischaemia (3 hours) was induced in a rat suture model followed by reperfusion (24 hours). Mikroplasmin (10 mg/kg), TNK (5 mg/kg), rt-PA (9 mg/kg) and saline (control), were administered. The volume of the ischaemic lesion was calculated, the loss of collagen type IV and the extravasation of haemoglobin were quantified by Western blotting. The matrix-metalloproteinases 2 and 9 (MMP-2/-9) were quantified by zymography and their endogenous tissue inhibitors (TIMPs) were analysed by reverse zymography. Microplasmin treatment caused the lowest volume of the ischaemic lesion (51.0 +/- 22.6 mm(3)) compared with control (167.3 +/- 13.1 mm(3); p<0.05). The content of collagen type IV was significantly increased and haemoglobin extravasation reduced (154 +/- 24%; p<0.05) compared with control (442 +/- 124%); MMP-2/-9 and the corresponding TIMPs remained unchanged. In comparison, TNK did not significantly reduce basal lamina damage and caused the highest extravasation. MMP-2/-9 were severely increased after TNK treatment (p<0.05). Thus, the balance between MMPs and TIMPs was shifted toward the inhibitory side with TNK. Microplasmin had a protective effect on the microvascular basal lamina and blood-brain barrier, whereas TNK was significantly disadvantageous from the viewpoint of ischaemic damage. Microplasmin also appears to be safer than other PAs in terms of damage to the microvasculature associated with thrombolytic therapy of ischaemic stroke.

Aspectos histoquímicos da membrana basal associados a variáveis clínicas em carcinoma epidermóide oral / Histochemical aspects of the basal membrane associated with clinical variables in oral squamous cell carcinoma

Objetivo: Avaliar o comportamento da membrana basal em lesões do carcinoma epidermóide oral, relacionando esse comportamento com a classificação clínica TNM, localização anatômica e sobrevida dos pacientes. Método: O estudo foi baseado em uma revisão retrospectiva incluindo a observação histológica de 20 casos de carcinoma epidermóide oral dos arquivos do Laboratório de Patologia do Hospital Estadual Dr. Luis Antônio em Natal, RN, Brasil. Com a análise dos prontuários médicos, foram obtidos os dados referentes à classificação clínica TNM e localização anatômica. A gradação histológica de malignidade foi realizada na área invasiva do tumor por dois patologistas em secções histológicas de 3 micrometros de espessura coradas pela hematoxilina e eosina (HE), para obtenção dos escores histológicos de malignidade, e pelo ácido periódico de Schiff (PAS) para o estudo da membrana basal. Resultados: O principal padrão de marcação da membrana basal foi contínuo, variando entre fraco, moderado e intenso, em lesões com baixo escore de malignidade e principalmente localizadas no lábio com a maioria dos pacientes livres da doença. Em lesões reincidentes principalmente em língua, com alto escore de malignidade, o padrão mais evidente de marcação da membrana basal foi descontínuo ou ausente. Conclusão: Lesões de língua com membrana basal descontínua ou ausente em pacientes com estadiamento clínico TNM III ou IV estão relacionadas com um prognóstico desfavorável, ao contrário, das lesões em lábio com a membrana basal contínua e estadiamento clínico TNM I ou II.

Objective: To evaluate the behavior of the basal membrane in oral squamous cell carcinoma lesions, relating this behavior to the TNM clinical classification, anatomic location and patient survival rate. Method: The study was based on a retrospective review, including the histological examination of 20 oral squamous cell carcinoma cases from the fi les of the Dr. Luis Antonio State Hospital's Pathology Laboratory in the city of Natal, RN, Brazil. Data referring to TNM clinical classification and anatomic location were obtained from the analysis of medical records. The histological grading of malignancy was made by the analysis of 3-micrometrics - thick histological sections stained with hematoxylin and eosin by two pathologists in order to obtain the histological malignancy scores, and by the periodic acid-Schiff (PAS) for the analysis of the basal membrane. Results: The main labeling pattern of the basal membrane was continuous, varying among weak, moderate and severe in lesions with low malignancy scores and were predominantly located in the lower lip in most healthy patients. For the recurrent lesions, mainly located on the tongue, with high malignancy scores, the most evident basal membrane labeling pattern was discontinuous or absent. Conclusion: Tongue lesions with discontinuous or absent basal membrane in patients in the III or IV TNM clinical stages are related to a poor prognosis, unlike lip lesions with continuous basal membrane and classified as I or II TNM clinical stages.

Inflamación, función renal residual, sobrehidratación y fallo de membrana. El cubo de Rubik de la diálisis peritoneal / No disponible

En los últimos años se han acumulado gran cantidad de evidencias, experimentales y clínicas, que apoyan la existencia de interacciones entre el declive de la función renal residual, el estado de hidratación, la aparición de estados inflamatorios y el deterioro funcional y estructural de la membrana peritoneal, en pacientes tratados con Diálisis Peritoneal. Estas interacciones son complejas, y distan de haber sido entendidas en su totalidad, pero cada una de las alteraciones citadas parece capaz de potenciar los efectos lesivos de las otras, afectando de manera clara a las probabilidades de supervivencia de estos pacientes. La preservación de la función renal residual y de la capacidad funcional de la membrana peritoneal, junto con otras medidas destinadas a prevenirla sobre hidratación y reducir la intensidad de los fenómenos inflamatorios constituyen mecanismos esenciales de prevención de riesgo en estos pacientes, y deben ser abordados desde una perspectiva conjunta. Las nuevas soluciones de Diálisis Peritoneal, aparentemente más biocompatibles, podrían jugar un papel esencial en la consecución de estos objetivos (AU)

Over the last years, a large amount of experimental and clinical evidence has been accumulated that supports the existence of interactions between the decline in residual renal function, hydration status, inflammatory states and functional and structural deterioration of the peritoneal membrane in patients treated with peritoneal dialysis. These interactions are complex and remain far from being fully understood, but each one of these alterations appears to be capable of aggravating the harmful effects of the others, clearly affecting the probabilities of survival of these patients. Preservation of residual renal function and functional capacity of the peritoneal membrane, together with other measures to prevent over hydration and reduce the intensity of inflammatory phenomena, are essential mechanisms for risk prevention in these patients, and should be addressed from a joint perspective. New peritoneal dialysis solutions, apparently more biocompatible, could play an essential role in the achievement of these objectives (AU)

Bases teóricas para la propuesta de un ensayo clínicoaleatorizado, controlado y abierto, para evaluarla eficacia de la adición de bemiparina a la solución de icodextrina en pacientes en diálisis peritoneal con trastornos del transporte peritoneal[FRIAT-BEM-2005-01] / No disponible

Considerando todas las investigaciones realizadas hasta la fecha sobre las causas que contribuyen al deterioro de la membrana peritoneal y su fisiopatología, se puede concluir que es de gran interés investigar si la administración de heparinaintraperitoneal puede aportar un beneficio sobre el mantenimiento de la función peritoneal en los enfermos tratados con diálisis peritoneal (DP). Las acciones descritas a favor de esta idea son:1) La inflamación crónica del peritoneo es una causa de alteración de la función peritoneal y la heparina tiene acciónantiinflamatoria.2) La fibrosis peritoneal debida a diálisis peritoneal o a traumatismo puede ser evitada o mejorada con heparina ip.3) La heparina (HNF y HBPM, incluida bemiparina) indúcela síntesis de tPA por las células mesoteliales, lo que supone una acción fibrinolítica.4) La heparina, más la HBPM que la HNF, inhibe la angiogénesis.5) La heparina intraperitone al favorece la eliminación delos AGE en la DP.6) Modelos animales y estudios clínicos de corta extensión han demostrado una mejora de la función peritoneal con heparina.7) Por el momento, no se han encontrado problemas de seguridad en su administración intraperitoneal. Es por tanto una hipótesis verosímil que el uso de heparinaintraperitoneal puede modificar favorablemente la función peritoneal de pacientes en diálisis peritoneal (AU)

Multiple investigations performed on peritoneal pathophysiology during peritoneal dialysis (PD) suggest that intraperitonealheparin might modify most of the causes of membrane deterioration. The actions described favouring this idea are:1) Peritoneal Chronic inflammation alters peritoneal function and heprain has anti-inflammatory properties.2) Peritoneal fibrosis related to peritoneal dialysis or traumaticinjury may be avoided or limited with heparin.3) Heparine induces tPA síntesis by mesothelial cells, which represents a potentiation of fibrinolytic action.4) Heparine, sècifically low-molecular weight heparin, inhibitsangiogenesis.5) Intraperitoneal heparin favors the removal of advanced glycosilation end products in PD.6) Animal models and clinical studies with small series of patients have demonstrated an improvement of peritoneal function with intraperitoneal heparine use.7) Until now, no adverse effects of the intraperitoneal heparinuse have been found. In consequence, it is a plausible hipothesis to consider that intraperitonealheparin may favourably modify peritoneal function inpatients under peritoneal dialysis (AU)

What differentiates normal lung repair and fibrosis? Inflammation, resolution of repair, and fibrosis.

There has been ongoing controversy related to what differentiates normal lung repair and fibrosis. For example, the current prevailing concept has been that idiopathic forms of pulmonary fibrosis are due only to epithelial injury in response to some unknown cause that results in persistent evolving fibrosis without preceding inflammation. This concept would suggest that the lung responds to injury in a different manner than other organs, such as the liver, kidney, and heart. However, that would seem to contradict known established pathological concepts. To address this controversy, concepts were presented as follows: (1) loss of basement membrane integrity is critical in determining the "point of no return," and contributes to the inability to reestablish normal lung architecture with promotion of fibrosis; (2) loss of epithelial cells, endothelial cells, and basement membrane integrity in usual interstitial pneumonia associated with idiopathic pulmonary fibrosis leads to destroyed lung architecture and perpetual fibrosis; (3) transforming growth factor-beta is necessary, but not entirely sufficient, to promote permanent fibrosis; (4) persistent injury/antigen/irritant is critical for the propagation of fibrosis; (5) idiopathic pulmonary fibrosis is an example of a process related to the persistence of an "antigen(s)," chronic inflammation, and fibrosis; and (6) unique cells are critical cellular players in the regulation of fibrosis. In keeping with the theme of the Aspen Lung Conference, it is hoped that more questions are raised than answered in this presentation, in support of the continued need for research in this area to address these important concepts.

Tearing and folding of the retinal internal limiting membrane associated with macular epiretinal membrane.

PURPOSE: To describe the clinical and histologic features of a particular form of macular epiretinal membrane. METHODS: The charts of all patients operated for macular epiretinal membrane by a single surgeon (E.H.B.) between June 2001 and January 2005 were retrospectively reviewed. Patients with macular epiretinal membrane associated with tearing and folding of the internal limiting membrane (ILM) were identified and the following parameters were recorded when available: age, gender, best-corrected visual acuity before and after vitrectomy; optical coherence tomography; pre-, intra-, and postoperative macular status; intraoperative staining by indocyanine green; histology. RESULTS: Twenty-three of 268 eyes (8.6%) with macular epiretinal membrane were associated with tearing and folding of the ILM, forming a whitish prominent band on the surface of the retina. The mean age of the patients was 68.6 years with a significant female predominance (78.3%). The vitreous was completely detached in 21 eyes. After surgical peeling, the mean visual gain was 3.2 Early Treatment Diabetic Retinopathy Study lines. No recurrence was observed. CONCLUSION: Tearing and folding of the ILM was associated with macular epiretinal membranes in 8.6% of cases. The ILM was probably torn during posterior hyaloid detachment, but the pathogenesis has not been clearly elucidated. The surgeon should begin to peel the macular epiretinal membrane by grasping the folded ILM to ensure complete removal of the ILM together with the epiretinal membrane. The postoperative visual prognosis was good.

Effects of the matrix metalloproteinase inhibitor GM6001 on the destruction and alteration of epithelial basement membrane during the healing of post-alkali burn in rabbit cornea.

PURPOSE: To examine the alteration in structure and matrix composition of epithelial basement membrane (BM) during the healing of alkali-burned rabbit cornea, and the roles of matrix metalloproteinases (MMPs) in these alterations. METHODS: The central cornea of one eye of 78 albino rabbits was exposed to 1 N NaOH for 180 s under general and topical anesthesia and allowed to heal with or without subconjunctival injection of GM6001 (an MMP inhibitor). Cryosections of affected corneas were observed by H&E staining, immunohistochemistry for type IV collagen subtypes, or in situ zymography for detection of localization of MMP activity. RESULTS: Uninjured corneal epithelial BM exhibited alpha5 (IV)-immunoreactivity, but lacked the alpha1/alpha2-immunoreactivity of collagen IV. Epithelial BM in healing burned cornea transiently exhibited alpha1/alpha2-immunoreactivity. Examination by in situ zymography showed an upregulation of MMP activity in the regenerated central epithelium and anterior stroma of the burned corneas at days 7 and 14. GM6001 suppressed degradation of alpha5-containing epithelial BM in vivo and also in organ culture. CONCLUSIONS: Epithelial BM was degraded by endogenous MMPs during healing following an alkali burn in rabbit cornea. GM6001 had an inhibitory effect on the degradation of the epithelial basement membrane in burned cornea in vivo.