Disentangling functional trait variation and covariation in epiphytic lichens along a continent-wide latitudinal gradient.

Characterizing functional trait variation and covariation, and its drivers, is critical to understand the response of species to changing environmental conditions. Evolutionary and environmental factors determine how traits vary among and within species at multiple scales. However, disentangling their relative contribution is challenging and a comprehensive trait-environment framework addressing such questions is missing in lichens. We investigated the variation in nine traits related to photosynthetic performance, water use and nutrient acquisition applying phylogenetic comparative analyses in lichen epiphytic communities on beech across Europe. These poikilohydric organisms offer a valuable model owing to their inherent limitations to buffer contrasting environmental conditions. Photobiont type and growth form captured differences in certain physiological traits whose variation was largely determined by evolutionary processes (i.e. phylogenetic history), although the intraspecific component was non-negligible. Seasonal temperature fluctuations also had an impact on trait variation, while nitrogen content depended on photobiont type rather than nitrogen deposition. The inconsistency of trait covariation among and within species prevented establishing major resource use strategies in lichens. However, we did identify a general pattern related to the water-use strategy. Thus, to robustly unveil lichen responses under different climatic scenarios, it is necessary to incorporate both among and within-species trait variation and covariation.

A case study on the re-establishment of the cyanolichen symbiosis: where do the compatible photobionts come from?

BACKGROUND AND AIMS: In order to re-establish lichen symbiosis, fungal spores must first germinate and then associate with a compatible photobiont. To detect possible establishment limitations in a sexually reproducing cyanolichen species, we studied ascospore germination, photobiont growth and photobiont association patterns in Pectenia plumbea. METHODS: Germination tests were made with ascospores from 500 apothecia under different treatments, and photobiont growth was analysed in 192 isolates obtained from 24 thalli. We determined the genotype identity [tRNALeu (UAA) intron] of the Nostoc cyanobionts from 30 P. plumbea thalli from one population. We also sequenced cyanobionts of 41 specimens of other cyanolichen species and 58 Nostoc free-living colonies cultured from the bark substrate. KEY RESULTS: Not a single fungal ascospore germinated and none of the photobiont isolates produced motile hormogonia. Genetic analyses revealed that P. plumbea shares Nostoc genotypes with two other cyanolichen species of the same habitat, but these photobionts were hardly present in the bark substrate. CONCLUSIONS: Due to the inability of both symbionts to thrive independently, the establishment of P. plumbea seems to depend on Dendriscocaulon umhausense, the only cyanolichen species in the same habitat that reproduces asexually and acts as a source of appropriate cyanobionts. This provides support to the hypothesis about facilitation among lichens.

Blend design tools for Medium Combustion Plants (MCP) firing biomass wastes.

A feasible alternative for agricultural or forestry waste management is the operation of a distributed network of sustainable Medium Combustion Plants (MCPs). However, one of the main factors that hinder its development is the propensity to operational problems derived from corrosion, slagging and fouling characteristics of both bottom and fly ashes. Therefore, a cost-effective approach for these multi-product MCP could be based on predictive tools for an optimal formulation of a fuel blend. This work focuses on the assessment of the ability of these methods to provide guidance for preventing ash-related operational problems and to provide fuel-blending rules. The more widespread tools pertain to two types: compositional classification based on chemical analysis of laboratory ashes, and thermodynamic prediction of the most likely species and phases. Both criterion numbers and compositional maps are ranking methods based on the chemical analysis at a given ashing temperature. Thermodynamic equilibrium modeling is not constrained by any difference in the physical conditions of the MCP compared to those in the laboratory. Both kind of prediction tools have been validated in an MCP firing olive tree pruning residues as well as its typical blends in order to mimic a plausible pattern of fuels along a full year operating campaign. An intensive experimental campaign encompasses plant monitoring and off-line analysis of the ashes along the process line. Interpretation of compositional plots has revealed to be potentially sensitive to ashing temperature. Here are presented examples showing how this variable could lead to either insignificant differences or to a substantial disparity in the a priori fuel diagnosis. Some inconsistencies have been observed between the predictions based on criterion numbers, even for the same fuel and for ranking rules specifically formulated for biomasses. Moreover, it does not match consistently with the information obtained from phase diagrams. Therefore, their use should be limited to the case of a well-established selection of a fuel index for a well-defined fuel provided empirical evidence of an enough good description of the ash behavior, which is not the most frequent case. Thermodynamic equilibrium calculations allow a more precise prediction of the main species in the condensed phase, without the constraint of the ashing temperature. Elemental closure of main ash-forming elements with the chemical analysis of the process ashes presents small differences, and their proximity localization on the phase diagrams denote similar prediction between predicted and process ashes.

A Strategic Study about Quality Characteristics in e-Health Systems Based on a Systematic Literature Review.

e-Health Systems quality management is an expensive and hard process that entails performing several tasks such as analysis, evaluation, and quality control. Furthermore, the development of an e-Health System involves great responsibility since people's health and quality of life depend on the system and services offered. The focus of the following study is to identify the gap in Quality Characteristics for e-Health Systems, by detecting not only which are the most studied, but also which are the most used Quality Characteristics these Systems include. A strategic study is driven in this paper by a Systematic Literature Review so as to identify Quality Characteristics in e-Health. Such study makes information and communication technology organizations reflect and act strategically to manage quality in e-Health Systems efficiently and effectively. As a result, this paper proposes the bases of a Quality Model and focuses on a set of Quality Characteristics to enable e-Health Systems quality management. Thus, we can conclude that this paper contributes to implementing knowledge with regard to the mission and view of e-Health (Systems) quality management and helps understand how current researches evaluate quality in e-Health Systems.

Evaluación de la composición nutricional, antinutricional y biodisponibilidad in vitro de diferentes extractos foliares / Evaluation of the nutritional and antinutritional composition and in vitro bioavailability of foliar extracts

Foliar extracts (FEs) are an alternative to address food and nutrition insecurity. FEs and leaves of cassava, bean, sweet potato and alfalfa were evaluated for nutrient and antinutrient composition and in vitro nutrient bioavailability. Bean FE had a high average ± (SD) iron concentration (1006 ± 8.49 mg/kg), as did cassava FE for zinc (110.1 ± 6.72 mg/kg) and soluble protein (34.23 ± 3.81 g/kg) concentration. For the cassava, bean and alfalfa FEs in vitro protein digestibility was greater than 71.18 percent; in vitro iron dialyzability was less than 2.29 percent; the phytate:zinc molar ratio was less than 0.08, and the in vitro all-trans-β-carotene bioavailability was greater than 23.85 percent. These values suggest a high protein, zinc and all-trans- β -carotene bioavailability and a low iron bioavailability. FEs can be a nutritious alternative for those countries with low dietary diversity.

Los extractos foliares (EF) son utilizados como complemento nutricional en países como Nicaragua y Tanzania. Se evaluaron hojas y EF de yuca, fríjol, batata y alfalfa, y se cuantificó los componentes nutricionales, antinutricionales y biodisponibilidad por métodos in vitro. En promedio (DE), el EF de fríjol tiene una elevada concentración de hierro (1006,23 (8,49) mg/kg); el EF de yuca tiene alta concentración de zinc (110,65 (6,72) mg/ kg) y proteína soluble (34,23 (3,81) g/kg). Así mismo, la digestibilidad in vitro de proteína en los EFs de yuca, fríjol y alfalfa fueron superiores a 71,18 por ciento; hierro dializable in vitro menor a 2,29 por ciento; la relación molar fitato:zinc inferior a 0,08 y la bioaccesibilidad all-trans-β -caroteno superior a 23,85 por ciento. Estos valores sugieren una alta asimilación de proteína, zinc y all-trans-β -caroteno, y una baja asimilabilidad de hierro. Los EFs pueden ser una alternativa nutricional en la alimentación en países que carecen de diversificación alimentaria.

Muerte encefálica: la necesidad de una causa suficiente y necesaria: a propósito de un caso de deseferentación completa por síndrome de Guillain Barré / Brain death: the need for sufficient and necessary cause: apropos of a complete deseferentation case from Guillain Barre syndrome

La muerte encefálica es una causa válida en la certificación del deceso de un paciente, especialmente en condiciones de donación de órganos. Existen escasas situaciones en las que el legislador ha propuesto la realización de exámenes complementarios para su certificación. Presentamos el caso de un paciente con un síndrome de Guillain Barré, que llegó a simular un estado de muerte encefálica, debido al compromiso motor completo, incluyendo musculatura ocular intrínseca. La falta de una condición suficiente y necesaria para declarar la muerte del paciente lleva a la solicitud de exámenes complementarios, en este caso un electroencefalograma, los que determinan la normalidad de la actividad eléctrica cerebral. Se recalca la necesidad de cumplir estrictamente los criterios para determinar la muerte encefálica y el no inhibirse de solicitar exámenes complementarios en condiciones de duda, aún cuando la ley no siempre lo contemple.

Brain death is a valid cause of death certification in a patient, especially in terms of organ donation. There are few situations in which the legislator has proposed further examination for certification. We report the case of a patient with Guillain Barré syndrome, which came to simulate a state of brain death due to motor impairment in full, including intrinsic ocular muscles. The lack of a necessary and sufficient condition for declaring the patient's death led to request additional examinations, in this case an electroencephalogram, which determine the normality of brain electrical activity. It emphasizes the need to comply strictly with the criteria for determining brain death and not to request additional examinations inhibited in a position of doubt, even though the law does not always contemplated.

[Leprosy and severe neuropathy in two native Spaniards]. / Lepra y neuropatía grave en dos nativos españoles.

INTRODUCTION: Leprosy is a widespread infectious disease in humans that is endemic to regions with poor sanitary conditions, especially in cases of overcrowding, malnutrition and bad hygiene. The disease is characterised by dermopathy, which is quite typical, but above all by neuropathy, which often becomes the most important element. In most cases, alterations to nerves are defined by sensory deficits that are predominantly distal and multiple neuritis in areas where nerve entrapment has taken place. CASE REPORTS: Two patients, both native Spaniards, presented largely overlapping clinical pictures, that is, a history of 'glove and stocking' type paresthesias and dysesthesias going back months or even years and functional impotence, which gave rise to a very pronounced gait disorder. In the two cases, the immunological situation was determined to be borderline lepromatous leprosy. The neurophysiological study revealed the presence of severe, diffuse sensory-motor axonal polyneuropathy that was predominantly distal, and several entrapped nerves. The dermatological illness was greatly improved by the treatment. The same was partially true, although to a satisfactory extent, of the neurological disease. CONCLUSION: We describe the cases of two Spaniards with borderline lepromatous leprosy with no past history of the disease, in whom neuropathy was the predominant symptom. We highlight the speed with which the neuropathies progressed, probably due to a change in 'polarity', and the severity of the neurological deficits in comparison with the dermopathy, in an unusual immunological situation. The growing number of native patients in the first world, even when there is no relevant history, suggests that we should not think of leprosy as something only occurring in immigrant patients from places where it is endemic, although the epidemiological relationship has still not been determined.

Lepra y neuropatía grave en dos nativos españoles / Leprosy and severe neuropathy in two native spaniards

La lepra es una infección humana extendida, endémica de regiones con malas condiciones sanitarias,en especial hacinamiento, malnutrición y mala higiene. La enfermedad se caracteriza por dermopatía, bastante típica; pero, sobre todo, neuropatía, que se convierte con mucha frecuencia en protagonista. La alteración del nervio viene definida en la mayor parte de casos por déficit sensitivos de predominio distal y multineuritis en lugares de atrapamiento nervioso. Casosclínicos. Dos pacientes, españoles indígenas, presentaron cuadros muy superponibles: parestesias y disestesias continuas en guante y calcetín de meses o incluso años de evolución, e impotencia funcional, en uno de los casos provocando un trastornode la marcha muy importante. En los dos se estableció la situación inmunológica como lepra borderline lepromatosa. El estudio neurofisiológico determinó la presencia de polineuropatía axonal sensitivomotora grave y difusa de predominio distal, y varios atrapamientos nerviosos. El tratamiento mejoró muy significativamente la enfermedad dermatológica y, de maneraparcial, aunque satisfactoria, la neurológica. Conclusión. Describimos dos españoles con lepra borderline lepromatosa sin antecedentes, en los que predominó sintomáticamente la neuropatía. Destacamos la rápida progresión de las neuropatías,probablemente por un cambio en la ‘polaridad’, la gravedad de los déficit neurológicos en contraste con la dermatopatía, en una situación inmunológica poco habitual. El número creciente de afectados indígenas del primer mundo, incluso sin antecedentesrelevantes, indica que no sólo debemos pensar en lepra en pacientes inmigrantes procedentes de lugares endémicos, aunque la relación epidemiológica está por determinar

Leprosy is a widespread infectious disease in humans that is endemic to regions with poor sanitaryconditions, especially in cases of overcrowding, malnutrition and bad hygiene. The disease is characterised by dermopathy, which is quite typical, but above all by neuropathy, which often becomes the most important element. In most cases, alterationsto nerves are defined by sensory deficits that are predominantly distal and multiple neuritis in areas where nerve entrapment has taken place. Case reports. Two patients, both native Spaniards, presented largely overlapping clinical pictures, that is, ahistory of ‘glove and stocking’ type paresthesias and dysesthesias going back months or even years and functional impotence, which gave rise to a very pronounced gait disorder. In the two cases, the immunological situation was determined to beborderline lepromatous leprosy. The neurophysiological study revealed the presence of severe, diffuse sensory-motor axonal polyneuropathy that was predominantly distal, and several entrapped nerves. The dermatological illness was greatly improved by the treatment. The same was partially true, although to a satisfactory extent, of the neurological disease. Conclusion. Wedescribe the cases of two Spaniards with borderline lepromatous leprosy with no past history of the disease, in whom neuropathy was the predominant symptom. We highlight the speed with which the neuropathies progressed, probably due to a change in ‘polarity’, and the severity of the neurological deficits in comparison with the dermopathy, in an unusualimmunological situation. The growing number of native patients in the first world, even when there is no relevant history, suggests that we should not think of leprosy as something only occurring in immigrant patients from places where it is endemic, although the epidemiological relationship has still not been determined

[Adaptogenic effect of the vitamin D3 containing supplement "videchol" on glucose-6-phosphate dehydrogenase activity in erythrone of irradiated rats].

Two fast migrating, major, multiple molecular forms (MMF) of glucose-6-phosphate dehydrogenase [EC:1.1.1.49]: G-6-PDH-1 and G-6-PDH-2, and two minor forms: G-6-PDH-3 and G-6-PDH-4 were revealed in the electrophoregrams of both erythrocytes haemolisates as well in the homogenates of bone marrow cellular lines of rats at control conditions. Daily 1 cGy irradiation of rats up to a cumulative dose of 20 cGy led to a drop of G-6-PDH total activity and it caused a redistribution of the MMF of the enzyme in bone marrow cellular populations. However, G-6-PDH activity in erythrocytes exceeded the control means in all the experimental terms. The calculation of the local redistribution coefficient (l(G-6-FDH-i)) showed that these changes are mainly determined by the increase of the activity of the isoform G-6-PDH-3. Vitamin D3 administration to rats generated a correction of G-6-PDH activity in all studied cellular populations. Meanwhile, the MMF profiles were characterized by multidirectional rearrangements in the bone marrow erythroid and granulocyte-monocyte cells and in erythrocytes. The specificity of changes in the distribution of the MMF of G-6-PDH in the three studied cellular populations depends on the particularities of their energetic metabolism at irradiation conditions and on the modifying action of the natural adaptogen 1,25-dihydroxicholecalciferol.

Pharmacokinetics and tissue penetration of pefloxacin plus metronidazole after administration as surgical prophylaxis in colorectal surgery.

The levels of metronidazole and pefloxacin in plasma and tissue penetration of both drugs were studied after prophylactic administration to 7 patients undergoing colorectal surgery. Metronidazole (1,500 mg) and pefloxacin (800 mg) were administered as an intravenous infusion 1 hour before surgery. Mean plasma levels of pefloxacin decreased from 12.92 +/- 4.10 microg/ml at the end of the infusion to 2.18 +/- 1.03 microg/ml at 36 h. These values were above the MIC90 for E. coli (0.125 microg/ml) and E. faecalis (0.5 microg/ml), microorganisms responsible for abdominal infections. Tissue pefloxacin levels were also measured with a range from 0.72 - 7.78 microg/g in subcutaneous cell tissue, from 1.94 - 17.55 microg/g in peritoneum and from 2.76 - 21.99 microg/g in colon wall. Mean plasma concentrations of metronidazole decreased from 39.89 +/- 17.08 microg/ml at the end of the infusion to 2.63 +/- 1.11 microg/ml at 36 h. During this period, concentrations were higher than 2 microg/ml, the MIC90 value for B. fragilis, the anaerobic pathogen more frequently involved in postoperative infections after rectal and colonic surgery. Tissue metronidazole levels ranged from 3.64 - 13.37 microg/g in subcutaneous cell tissue, from 3.26 - 41.66 microg/g in peritoneum and from 6.72 - 43.12 microg/g in colon wall. The AUC/MIC values (efficacy parameter for concentration-dependent killing antibiotics such as pefloxacin and metronidazole) obtained were the following: metronidazole AUC/MIC value for B. fragilis was 173; pefloxacin AUC/MIC values for E. coli and E. faecalis were 941 and 235, respectively. The values of these parameters are higher than the recommended values to ensure efficacy, which means good exposure of the antimicrobials to the microorganisms. In conclusion, the combination of pefloxacin and metronidazole as prophylactic agents to prevent infections in patients undergoing colorectal surgery produce plasma and tissue levels above the MIC values of the main pathogens responsible for this kind of infections.

Sand bar opening in a coastal lagoon (Iquipari) in the northern region of Rio De Janeiro State: hydrological and hydrochemical changes.

The aim of this paper was to verify hydrological and hydrochemical changes in the Iquiparí Lagoon water column, during three months, as related to an artificial sand bar opening. A drastic reduction in water volume occurred 28 hours after the sand bar opening, exposing the bottom sediment. This was densely colonized by submerged aquatic plants, which were dominant in the ecosystem metabolism, specially near the sand bar. An increase in salinity values, and dissolved and total nutrient concentrations, was observed during the sand bar opening period. In contrast, chlorophyll a concentration decreased. These changes were associated with: 1) mix of remained brackish and marine waters; 2) nutrient release from sediments by physical processes; and 3) submerged plant death. After the sand bar closure, lagoon metabolism was completely regulated by a dense phytoplankton community. We observed that the sand bar opening resulted in an extensile replacement of the lagoon's water and a change in the community mainly responsible for the ecosystem metabolism.

Sand bar opening in a coastal lagoon (Iquipari) in the northern region of Rio de Janeiro State: hydrological and hydrochemical changes

The aim of this paper was to verify hydrological and hydrochemical changes in the Iquiparí Lagoon water column, during three months, as related to an artificial sand bar opening. A drastic reduction in water volume occurred 28 hours after the sand bar opening, exposing the bottom sediment. This was densely colonized by submerged aquatic plants, which were dominant in the ecosystem metabolism, specially near the sand bar. An increase in salinity values, and dissolved and total nutrient concentrations, was observed during the sand bar opening period. In contrast, chlorophyll a concentration decreased. These changes were associated with: 1) mix of remained brackish and marine waters; 2) nutrient release from sediments by physical processes; and 3) submerged plant death. After the sand bar closure, lagoon metabolism was completely regulated by a dense phytoplankton community. We observed that the sand bar opening resulted in an extensile replacement of the lagoon's water and a change in the community mainly responsible for the ecosystem metabolism.

O presente trabalho teve por objetivo avaliar as alterações hidrológicas e hidroquímicas na coluna d'água da lagoa costeira de Iquiparí, ao longo de três meses, quando esta foi submetida a processo artificial de abertura de barra. Nas 28 horas que se seguiram à abertura da barra, o volume de água foi drasticamente reduzido. Os sedimentos de fundo, densamente colonizados por plantas aquáticas submersas que dominavam o metabolismo da lagoa costeira, foram em grande parte expostos ao ar, principalmente nas porções mais próximas ao mar. Observou-se, durante o período em que a barra esteve aberta, grande elevação da salinidade e da concentração de nutrientes dissolvidos e totais, e, em contraste, redução da biomassa fitoplanctônica. Estes fatos estão associados a: 1) mistura da água salobra remanescente com a marinha; 2) processos físicos de liberação de nutrientes do sedimento; e 3) morte das plantas submersas. Após o fechamento da barra, foi constatado intenso desenvolvimento da comunidade fitoplanctônica, que passou a dominar o metabolismo do ecossistema, especialmente nas porções mais próximas ao mar. Verificou-se que a abertura da barra resultou em substituição quase total das águas da lagoa costeira e alterou o tipo de comunidade predominante no metabolismo do sistema.

Sand bar opening in a coastal lagoon (Iquipari) in the northern region of Rio de Janeiro State: hydrological and hydrochemical changes

The aim of this paper was to verify hydrological and hydrochemical changes in the Iquiparí Lagoon water column, during three months, as related to an artificial sand bar opening. A drastic reduction in water volume occurred 28 hours after the sand bar opening, exposing the bottom sediment. This was densely colonized by submerged aquatic plants, which were dominant in the ecosystem metabolism, specially near the sand bar. An increase in salinity values, and dissolved and total nutrient concentrations, was observed during the sand bar opening period. In contrast, chlorophyll a concentration decreased. These changes were associated with: 1) mix of remained brackish and marine waters; 2) nutrient release from sediments by physical processes; and 3) submerged plant death. After the sand bar closure, lagoon metabolism was completely regulated by a dense phytoplankton community. We observed that the sand bar opening resulted in an extensile replacement of the lagoon's water and a change in the community mainly responsible for the ecosystem metabolism

Effect of a vitamin D3-based nutritional supplement ('Videchol') on carbohydrate metabolism of rats following chronic low dose-rate irradiation.

In this study we evaluated the effects of the administration of a vitamin D3 preparation 'Videchol' to chronically irradiated rats (1 cGy day(-1)) by the assessment of the activities of several glycolytic enzymes: lactic dehydrogenase (LDH) (EC 1.1.1.28), pyruvate kinase (PK) (EC 2.7.1.40) and hexokinase (HK) (EC 2.7.1.1), in populations of erythroid and myeloid bone marrow cells. Videchol treatment of irradiated rats led to the normalisation of HK and LDH activity at cumulative doses of around 30 cGy in granulocyte-monocyte cells and to normalisation of LDH and PK activities in erythroid cells starting at 20 cGy in comparison with irradiated rats who did not receive Videchol. The reaction kinetic parameters of LDH in erythrocytes changed according to the redistribution pattern of the isozymes throughout the different stages of the experiment. The administration of Videchol to irradiated rats led to a rearrangement of the LDH isozymes ratio characterised by kinetic properties more comparable to those of the controls. Thus, vitamin D3 appears to induce a normalisation of carbohydrate metabolism in rats chronically irradiated with low dose-rate ionising radiation.

Particle irradiation induces FGF2 expression in normal human lens cells.

Particle Irradiation Induces FGF2 Expression in Normal Human Lens Cells. Particle radiations, including both proton and helium-ion beams, have been used to successfully treat choroidal melanoma, but with the complication of radiation-induced cataract. We have investigated a role for radiation-induced changes in the expression of basic fibroblast growth factor (FGF2) gene expression as part of the mechanism(s) underlying lens cell injury associated with cataract. Normal human lens epithelial (HLE) cells were cultured in vitro on extracellular matrix (ECM) originated from bovine corneal endothelial cells. This study reports evidence for rapid but transient induction of FGF2 transcripts, an increase of between 5- and 8-fold, within 0.5 h after exposure to particle radiation, followed by another wave of increased transcription at 2-3 h postirradiation. Immunofluorescence results confirm the enhanced levels of FGF2 protein rapidly after exposure to protons or helium ions, followed by another wave of increased activity unique to helium at 6 h postirradiation. This second wave of increased immunoreactivity was not observed in the proton-irradiated samples. Total FGF2 protein analysis after helium-ion exposures shows induced expression of three FGF2 isoforms, with an increase of up to 2-fold in the 18-kDa low-molecular-weight species. Studies of the effects of protons on individual FGF2 protein isoforms are in progress. Several mechanisms involving a role for FGF2 in radiation-induced cataract are discussed.

Growth and differentiation of human lens epithelial cells in vitro on matrix.

PURPOSE: To characterize the growth and maturation of nonimmortalized human lens epithelial (HLE) cells grown in vitro. METHODS: HLE cells, established from 18-week prenatal lenses, were maintained on bovine corneal endothelial (BCE) extracellular matrix (ECM) in medium supplemented with basic fibroblast growth factor (FGF-2). The identity, growth, and differentiation of the cultures were characterized by karyotyping, cell morphology, and growth kinetics studies, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, and Western blot analysis. RESULTS: HLE cells had a male, human diploid (2N = 46) karyotype. The population-doubling time of exponentially growing cells was 24 hours. After 15 days in culture, cell morphology changed, and lentoid formation was evident. Reverse transcription-polymerase chain reaction (RT-PCR) indicated expression of alphaA- and betaB2-crystallin, fibroblast growth factor receptor 1 (FGFR1), and major intrinsic protein (MIP26) in exponential growth. Western analyses of protein extracts show positive expression of three immunologically distinct classes of crystallin proteins (alphaA-, alphaB-, and betaB2-crystallin) with time in culture. By Western blot analysis, expression of p57(KIP2), a known marker of terminally differentiated fiber cells, was detectable in exponential cultures, and levels increased after confluence. MIP26 and gamma-crystallin protein expression was detected in confluent cultures, by using immunofluorescence, but not in exponentially growing cells. CONCLUSIONS: HLE cells can be maintained for up to 4 months on ECM derived from BCE cells in medium containing FGF-2. With time in culture, the cells demonstrate morphologic characteristics of, and express protein markers for, lens fiber cell differentiation. This in vitro model will be useful for investigations of radiation-induced cataractogenesis and other studies of lens toxicity.