Mobility and postural limitations perceived by transtibial amputees undertaking agricultural activities: a qualitative study.

PURPOSE: In Colombia, 98% of landmines occur in rural areas, where the main victims of amputation are farmers. The challenges these amputees face in their agricultural work remain unknown. The aim of this study is to determine the mobility and postural limitations these farmers face in carrying out their daily activities. METHOD: Forty-nine participants meeting the following criteria were interviewed: transtibial amputee, 18 years and over, performs agricultural labour and wears the prosthesis daily. Subsequently, the interview transcripts were subjected to a content conventional analysis and responses were organized according to the abstraction process to identify categories and subcategories of the problems. RESULTS: Main problems reported were walking on sloping, uneven and wet terrain, problems associated with the stump skin, squatting, kneeling, using vehicles or animals for transportation and carrying objects over 30 kg. Postures such as sitting, running, jumping, and standing on tiptoes were mentioned less frequently. CONCLUSIONS: In conclusion, the prostheses worn by transtibial amputee farmers are not suitable for working on sloping and uneven terrain, nor for performing postures such as kneeling or squatting. These postures are very common in agricultural and livestock tasks in countries with mountainous areas such as Latin American countries. The recognition of problems reported by farmers transtibial amputees, may help to improve the design of prostheses so that they meet the needs of this population and decrease secondary injuries associated with prosthetic use. This information is useful to identify compensatory postures that facilitate prosthetic adaptation and rehabilitation for amputees.

Use of a Gemini-Surfactant Synthesized from the Mango Seed Oil as a CO2-Corrosion Inhibitor for X-120 Steel.

A gemini surfactant imidazoline type, namely N-(3-(2-fatty-4,5-dihydro-1H-imidazol-1-yl) propyl) fatty amide, has been obtained from the fatty acids contained in the mango seed and used as a CO2 corrosion inhibitor for API X-120 pipeline steel. Employed techniques involved potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. These tests were supported by detailed scanning electronic microscopy (SEM) and Raman spectroscopy studies. It was found that obtained gemini surfactant greatly decreases the steel corrosion rate by retarding both anodic and cathodic electrochemical reactions, with an efficiency that increases with an increase in its concentration. Gemini surfactant inhibits the corrosion of steel by the adsorption mechanism, and it is adsorbed on to the steel surface according to a Langmuir model in a chemical type of adsorption. SEM and Raman results shown the presence of the inhibitor on the steel surface.

Modulation of gut immune response by probiotic fermented milk consumption to control IgE in a respiratory allergy model.

Allergies are a world increasing health issue and most treatments are oriented to alleviate symptoms. Probiotics have several health benefits including the improvement of the immune system. In previous work we found that consumption of commercial probiotic fermented milk (PFM) significantly reduced specific-immunoglobulin (Ig) E in serum and lungs by increasing specific-IgG and controlled allergic response to ovalbumin (OVA) in an adult mouse respiratory allergy model. Here we continued our study determining the mechanism triggered in the gut by the PFM ingestion that influenced the results previously reported. Five groups of BALB/c mice were assessed: normal-control, basal (drinks PFM five days without OVA sensitisation), sensitisation-control (no PFM intake), previous and continuous-PFM administration. Allergen administration: 3 OVA injections (1% in PBS) followed by aerosols exposure for 7 days. We determined total secretory-IgA and cytokines in small intestine (SI) fluid; CD11b+, CD103+, IgA+ cells and cytokine producing cells in SI tissue. In lungs we analysed co-expression of CD4/interferon (IFN)-γ or CD4/interleukin (IL)-10, IgE+ cells and IL-12 production. Results: continuous intake of PFM increased the expression of CD103 marker and decreased CD11b and pro-inflammatory cytokines. Coexpression of CD4/IFN-γ was confirmed in lungs of animals that consumed PFM continuously. This group had a lower count of IgE+ cells and a higher concentration of IL-12. The consumption of PFM reinforces the mucosal barrier by increasing IgA+ cells and induces signalling from the intestine to the lungs by increasing the expression of CD103+ dendritic cells related to regulatory mechanisms. The results found in this work together with those previously reported demonstrated that the intake of PFM induces a clear balance towards the Th1 response, preventing the Th2 allergic response by controlling the previously reported IgE level. According to our model, the intake of PFM could be a good strategy to alleviate the development of allergies.

Respiratory allergy control by probiotic fermented milk intake: a mouse model from weaning to maturity.

This study is based on our previous research showing that commercial probiotic fermented milk (PFM) intake mitigates respiratory allergy development to ovalbumin (OVA) in adult mice (6-weeks old) increasing specific immunoglobulin (Ig)G2a and interferon (IFN)-γ rather than IgE. The aim was to determine if PFM exerts a protective effect when an allergy model is induced 5 days after weaning and whether the mechanisms involved are similar to those previously reported. Before inducing allergy, a group of 21-day old BALB/c mice received PFM for 10 days to analyse the impact on intestinal epithelial cells (IECs) activation. Two more groups received PFM for 5 days and were sensitised with OVA; only one group continued taking PFM until the end of the experiment. Sensitisation scheme: 3 OVA injections 1% in phosphate buffered saline (PBS) plus 7 days OVA aerosol exposure and re-stimulus 15 days later. The contents of specific- IgE, IgG, total-secretory-IgA and Th1/Th2 balance in serum, bronchoalveolar lavage (BAL) and gut were measured at 7 and 15 days post-sensitisation (dPS) and 2 days post-re-stimulus (2dPR). Treg cells in lungs were also quantified. Results were compared with normal and sensitised controls. PFM induced mild activation of IECs increasing monocyte chemoattractant protein-1 (MCP-1 or CCL2) and interleukin (IL)-6 production. In sensitised mice, PFM controlled the response inducing IgG rather than IgE at 7 and 15-dPS and 2dPR (60 days old). Th1-balance (IFN-γ) was favoured by PFM in lungs at 7 dPS with low levels of IL-10 released to regulate the response. Total-S-IgA increased in lungs and gut; however, PFM intake did not affect Treg cells in lungs. PFM maintains controlled stimulation of the immune cells involved in Th1 response, favouring IgG at the respiratory mucosal site. Although the effect was not as strong as that reported previously, PFM promoted maturation and activation of gut immune cells preserving intestinal homeostasis and lung immune response.

Imaging of the muscle and bone from benchtop to bedside.

Studies have begun to show that muscles and bones play a role in the regulation of biological functions through a combination of biomechanical and biochemical signals. In vivo and ex vivo imaging techniques are crucial in the understanding of the morphology and architecture of muscle and bone for further understanding of musculoskeletal physiology and pathophysiology. This systematic review of the literature summarizes current knowledge and outlines new insights into the functions of muscle and bone elucidated by imaging techniques, with a focus on the recent advances in the musculoskeletal system enabled by novel technologies, such as CLARITY, Fast Free-of-Acrylamide Clearing Tissue (FACT), computed tomography (CT), and positron emission tomography (PET). This may serve as guidance for the development of new strategies to prevent and diagnose motor or metabolism disorders related to the malfunction of muscle and bone.

Regulatory mechanisms involved in muscle and bone remodeling during refeeding in gilthead sea bream.

The tolerance of fish to fasting offers a model to study the regulatory mechanisms and changes produced when feeding is restored. Gilthead sea bream juveniles were exposed to a 21-days fasting period followed by 2 h to 7-days refeeding. Fasting provoked a decrease in body weight, somatic indexes, and muscle gene expression of members of the Gh/Igf system, signaling molecules (akt, tor and downstream effectors), proliferation marker pcna, myogenic regulatory factors, myostatin, and proteolytic molecules such as cathepsins or calpains, while most ubiquitin-proteasome system members increased or remained stable. In bone, downregulated expression of Gh/Igf members and osteogenic factors was observed, whereas expression of the osteoclastic marker ctsk was increased. Refeeding recovered the expression of Gh/Igf system, myogenic and osteogenic factors in a sequence similar to that of development. Akt and Tor phosphorylation raised at 2 and 5 h post-refeeding, much faster than its gene expression increased, which occurred at day 7. The expression in bone and muscle of the inhibitor myostatin (mstn2) showed an inverse profile suggesting an inter-organ coordination that needs to be further explored in fish. Overall, this study provides new information on the molecules involved in the musculoskeletal system remodeling during the early stages of refeeding in fish.

Biological and Cognitive Markers of Presenilin1 E280A Autosomal Dominant Alzheimer's Disease: A Comprehensive Review of the Colombian Kindred.

The study of individuals with autosomal dominant Alzheimer's disease affords one of the best opportunities to characterize the biological and cognitive changes of Alzheimer's disease that occur over the course of the preclinical and symptomatic stages. Unifying the knowledge gained from the past three decades of research in the world's largest single-mutation autosomal dominant Alzheimer's disease kindred - a family in Antioquia, Colombia with the E280A mutation in the Presenilin1 gene - will provide new directions for Alzheimer's research and a framework for generalizing the findings from this cohort to the more common sporadic form of Alzheimer's disease. As this specific mutation is virtually 100% penetrant for the development of the disease by midlife, we use a previously defined median age of onset for mild cognitive impairment for this cohort to examine the trajectory of the biological and cognitive markers of the disease as a function of the carriers' estimated years to clinical onset. Studies from this cohort suggest that structural and functional brain abnormalities - such as cortical thinning and hyperactivation in memory networks - as well as differences in biofluid and in vivo measurements of Alzheimer's-related pathological proteins distinguish Presenilin1 E280A mutation carriers from non-carriers as early as childhood, or approximately three decades before the median age of onset of clinical symptoms. We conclude our review with discussion on future directions for Alzheimer's disease research, with specific emphasis on ways to design studies that compare the generalizability of research in autosomal dominant Alzheimer's disease to the larger sporadic Alzheimer's disease population.

Dermatitis facial por Malassezia pachydermatis / Facial dermatitis caused by Malassezia pachydermatis

Se presenta un caso de dermatitis facial por Malassezia pachydermatis en un paciente de 34 años de edad, diagnosticado mediante clínica y estudio micológico. M. pachydermatis es una levadura que forma parte de la microbiota de mamíferos domésticos y animales salvajes, donde frecuentemente puede provocar dermatitis y otitis externa. En humanos, son escasas las infecciones por este agente, describiéndose desde infecciones superficiales hasta fungemias. En Chile se la ha encontrado como agente causal de pitiriasis versicolor y dermatitis seborreica principalmente en pacientes inmunocomprometidos.

We present a clinical case of facial dermatitis due to Malassezia pachydermatis in a patient of 34 years old, diagnosed by clinical and micology study. M. pachydermatis is a zoofilic yeast that is part of the microbiota of domestic mammals and wild animals, frequently causing dermatitis and external otitis. In humans, infections by this agent are very scarce, describing from superficial infections to fungemias. In Chile it has been found as causal agent of pitiriasis versicolor and seborrheic dermatitis mainly in inmunocompromised patients.

Understanding the reaction mechanism of the oxidative addition of ammonia by (PXP)Ir(i) complexes: the role of the X group.

An analysis of the electronic rearrangements for the oxidative addition of ammonia to a set of five representative (PXP)Ir pincer complexes (X = B, CH, O, N, SiH) is performed. We aim to understand the factors controlling the activation and reaction energies of this process by combining different theoretical strategies based on DFT calculations. Interestingly, complexes featuring higher activation barriers yield more exothermic reactions. The analysis of the reaction path using the bonding evolution theory shows that the main chemical events, N-H bond cleavage and Ir-H bond formation, take place before the transition structure is reached. Metal oxidation implies an electron density transfer from non-shared Ir pairs to the Ir-N bond. This decrement in the atomic charge of the metal provokes different effects in the ionic contribution of the Ir-X bonding depending on the nature of the X atom as shown by the interacting quantum atoms methodology.

Nitrogen doped carbon dots derived from Sargassum fluitans as fluorophore for DNA detection.

This work focused on the use of waste seaweed Sargassum fluitans (S. fluitans) as carbon source precursor to prepare nitrogen doped carbon dots (NCDs) by hydrothermal method. High resolution transmission electron microscopic (HR-TEM) studies revealed that the synthesized water soluble NCDs are in the size range of 2-8nm and exhibits excellent fluorescent properties with a quantum yield of 18.2%. Elemental nitrogen in NCDs was evidenced by X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectrum (FT-IR). The phytochemical analysis of S. fluitans using 1H NMR and 13C NMR revealed the presence of few amino acids which act as nitrogen source in the preparation of NCDs. Application of NCDs as fluorophore for double stranded DNA, single stranded DNA and RNA detection was highlighted in this study. Excellent fluorescent tagging abilities of NCDs with the biological nucleic acids were evidenced using gel electrophoresis. Significant increase in fluorescence was observed upon tagging of NCDs with nucleic acids and this particular phenomenon helps better in visualizing the nucleic acids. All three nucleic acids i.e. double stranded DNA, single stranded DNA and RNA showed similar phenomenon upon tagging with NCDs. Thus synthesized NCDs may be used as an alternate fluorophore for commercial toxic organic staining agents to visualize nucleic acids.

Growth-promoting effects of sustained swimming in fingerlings of gilthead sea bream (Sparus aurata L.).

Fish growth is strongly influenced by environmental and nutritional factors and changing culture conditions can help optimize it. The importance of early-life experience on the muscle phenotype later in life is well known. Here, we study the effects of 5 weeks of moderate and sustained swimming activity (5 BL s(-1)) in gilthead sea bream during early development. We analysed growth and body indexes, plasma IGF-I and GH levels, feed conversion, composition [proximate and isotopic ((15)N/(13)C)] and metabolic key enzymes (COX, CS, LDH, HOAD, HK, ALAT, ASAT) of white muscle. Moderate and continuous exercise in fingerlings of gilthead sea bream increased plasma IGF-I, whereas it reduced plasma GH. Under these conditions, growth rate improved without any modification to feed intake through an increase in muscle mass and a reduction in mesenteric fat deposits. There were no changes in the content and turnover of muscle proteins and lipid reserves. Glycogen stores were maintained, but glycogen turnover was higher in white muscle of exercised fish. A lower LDH/CS ratio demonstrated an improvement in the aerobic capacity of white muscle, while a reduction in the COX/CS ratio possibly indicated a functional adaptation of mitochondria to adjust to the tissue-specific energy demand and metabolic fuel availability in exercised fish. We discuss the synergistic effects of dietary nutrients and sustained exercise on the different mitochondrial responses.

Seguimiento y evaluación de las prácticas clínicas tuteladas con ayuda de la plataforma Moodle. Experiencia piloto y propuesta de mejora / Monitoring and evaluation of supervised clinical practice using the Moodle platform. Pilot experience and proposal for improvement

Introducción: Sin olvidar el papel primordial del tutor profesional y tutor académico en el seguimiento y evaluación de las prácticas clínicas que realizan nuestros estudiantes, Moodle ofrece una serie de herramientas que supone un soporte formativo para el estudiante y ayudan en el sistema de evaluación continuada y por competencias de esta asignatura. Objetivos: Evaluar la utilización de la plataforma en la implantación de recursos tales como: diario reflexivo, creación de un glosario y consulta de satisfacción como herramientas de apoyo en el seguimiento y evaluación de las prácticas clínicas. Material y métodos: estudio descriptivo transversal. Sujetos de estudio: alumnos de la diplomatura que han realizado prácticas clínicas supervisadas durante el curso académico 2010- 2011. Ámbito: Escuela de Enfermería Fundación Jiménez Díaz - Universidad Autónoma de Madrid. Herramientas: cuestionario realizado ad-hoc y análisis cualitativo y cuantitativo de los distintos recursos utilizados en el seguimiento y evaluación de las prácticas clínicas. Resultados: El 98% de los participantes consideran que el glosario ha contribuido mucho a su aprendizaje, un 86,1% de los participantes opinan lo mismo sobre el diario reflexivo, respecto a las prácticas clínicas, un 94% se siente muy satisfecho y, finalmente, más de un 80% de los alumnos de los tres cursos consideran que Moodle debería ampliarse a todas las asignaturas. Conclusiones: Moodle ha sido bien acogida por alumnos y tutores para el seguimiento y evaluación de la asignatura ‘Prácticas clínicas tuteladas’, y está resultando clave en el seguimiento de las tareas con las que se evalúan competencias de esta asignatura. La organización del material, el control en la entrega de las distintas tareas y la fácil asignación y calificación de las mismas son, sin duda, una ventaja clave (AU)

Introduction: Without underestimating the primary role of the professional tutor and academic tutor in the monitoring and evaluation of clinical practices made by our students, there is no doubt that Moodle offers a number of tools that can be a training support for the student and that are of great help in the system of continuous and competency-based assessment of this course. Objectives: To evaluate the use of the platform with the implementation of applications such as the reflective journal, the creation of a glossary and the evaluation of satisfaction meant to support in the monitoring and evaluation of clinical practices, and developing proposals for improvement. Material and methods: cross sectional study. Study subjects: the diploma students who have completed supervised clinical practice during the academic year 2010 to 2011. Scope: School of Nursing Fundación Jiménez Díaz - Universidad Autónoma de Madrid. Tools: ad-hoc questionnaire and conducted qualitative and quantitative analysis of the various resources used in monitoring and evaluation of clinical practice. Results: 98% of participants believe that the glossary has greatly contributed to their learning,, 86.1% of participants feel the same about the reflective journal, with respect to clinical practice,, 94% feel very satisfied, and finally, over 80% of students from the three courses believe Moodle should be extended to all subjects. Conclusions: Moodle has been welcomed by students and tutors for monitoring and evaluation of the supervised clinical practice, and it is crucial in monitoring the tasks used to evaluate skills in this subject. The organization of the material, control in the delivery of the various tasks and the easy assignment and qualification of these are undoubtedly a key advantage (AU)

Differential expression of genes encoding tight junction proteins in colorectal cancer: frequent dysregulation of claudin-1, -8 and -12.

BACKGROUND AND AIMS: As integral membrane proteins, claudins form tight junctions together with occludin. Several claudins were shown to be up-regulated in various cancer types. We performed an expression analysis of genes encoding tight junction proteins to display differential gene expression on RNA and protein level and to identify and validate potential targets for colorectal cancer (CRC) therapy. PATIENTS AND METHODS: Amplified and biotinylated cRNA from 30 microdissected CRC specimen and corresponding normal tissues was hybridized to Affymetrix U133set GeneChips. Quantification of differential protein expression of claudin-1, -8 and -12 between normal and corresponding tumour tissues was performed by Western blot analyses. Paraffin-embedded CRC tissue samples, colon cancer cell lines and normal tissue microarray were analysed for protein expression of claudin-1 by immunohistochemistry (IHC). RESULTS: Claudin-1 (CLDN1) and -12 (CLDN12) are frequently overexpressed in CRC, whereas claudin-8 (CLDN8) shows down-regulation in tumour tissue on RNA level. Quantification of proteins confirmed the overexpression of claudin-1 in tumour tissues, whereas changes of claudin-8 and -12 were not significantly detectable on protein level. IHC confirmed the markedly elevated expression level of claudin-1 in the majority of CRC, showing membranous and intracellular vesicular staining. CONCLUSIONS: Differential expression of genes encoding claudins in CRC suggests that these tight junction proteins may be associated to and involved in tumorigenesis. CLDN1 is frequently up-regulated in large proportion of CRC and may represent potential target molecule for blocking studies in CRC.

Meaning of illness and illness representations, crucial factors to integral care.

INTRODUCTION: A comprehensive study of end-stage renal disease (ESRD) and haemodialysis (HD) must include the sociocultural dimension of illness and the experience of patients from their own perspective. It is critical for the caring team to know how the disease is lived and reinterpreted by the patient, as this knowledge could improve nursing staff/patient interaction. The meaning of their experience is also an influential factor on the caring methods utilised by the patient. FRAMEWORK: The Theory of Representations and Explanatory Model of Illness was utilised in the study. METHODOLOGY: A narrative qualitative methodology, grounded in a constructivist paradigm was used. Twelve patients were interviewed. The interviews were audio taped and transcribed verbatim. RESULTS: Results revealed that patients have a range of beliefs about their illness and their treatment. Regarding identity, symptoms that arise at the outset of illness are not suspected of relating to renal failure. The inevitability of haemodialysis convinces patients of the presence of illness, opening a wide range of metaphors and symbolic representations. CONCLUSIONS: Representations of ESRD and HD conform to a multidimensional corpus where different elements of scientific order and common sense converge and interact, such as beliefs and fears. All of these contribute to the meaning of this illness and its treatment. The attributed meaning is dynamic being continually elaborated based on illness outcomes, adaptation to treatment, particular events and the sociocultural environment.

Method for analysis of polymer-supported organic compounds using mass spectrometry direct insertion.

A new approach on the use of mass spectrometry direct-insertion and a quadrupole detector for analysis of organic compounds supported in solid phase has been developed. This is a simple and efficient method based on cleavage due to the thermal-instability of the benzylic group of most commercial resins. The cleavage of supported compounds takes place in the spectrometer as a consequence of the high temperature in the instrument's chamber. These compounds are detected using a similar fragmentation pattern and a molecular ion corresponding to the same compound obtained by traditional synthesis. Polymer degradation fragments do not interfere with the spectrum interpretation, because only a few peaks and low intensities are detected. We report here the identification of different types of compounds supported in Merrifield resin, such as bis-o-aminobenzamides and simple aromatic and aliphatic compounds, using this new approach.

A practical approach to the molecular biology of kidney diseases: from basic science to bed side.

Nowadays, the term "Molecular Biology" (MB) is generally a pplied to the biochemical processes that involve genes and the expression of proteins for which specific genes code. In recent years, astonishing advances have occurred in this field. Currently, there are many important powerful techniques allowing scientists to study the molecular mechanisms involved in many human genetic diseases. Furthermore, it is important to underline that the possibilities are not limited to the diagnosis and study of these genetic diseases. Indeed, by studying gene expression, MB also allows the molecular study of many acquired diseases such as viral hepatitis and cancer.Therefore, these major advances in the knowledge of gene biology are facilitating the arrival of a new era of gene therapy. This article will describe the most important techniques currently used in MB. Firstly, techniques involved in recombinant DNA technology will be discussed and these will include the study of DNA and the possibility of identifying the expression of abnormal genes, e.g. to identify individuals for paternity. Secondly, a description of techniques designed to study the expression of genes and their regulation will follow and they involve the study of RNA. Thirdly, the impact of genetic molecular studies as tools for medical diagnosis will be discussed and analysed. Finally, a discussion concerning the rational basis for gene therapy and its future perspectives is included. In this article, we have focused on technical or diagnostic aspects ofMolecular Biology. Although Ethics are also an interesting issue to deal with, theseissues are far beyond the scope of this review.

Immunohistochemical expression of extracellular matrix proteins and adhesion molecules in pancreatic carcinoma.

BACKGROUND/AIMS: Carcinoma invasion and metastasis in general involve multiple steps including dynamic changes in the composition and structure of extracellular matrix proteins and cell surface receptors. In the present study, the usually highly invasive carcinoma of the pancreas was investigated regarding the expression of various extracellular matrix proteins and their corresponding integrin receptors, as well as E-cadherin. METHODOLOGY: Phenotypic expression of various markers was investigated immunohistochemically in frozen sections of 16 pancreatic carcinomas and normal pancreatic tissue. RESULTS: An irregular and discontinuous deposition of type IV collagen and laminin in the basement membrane was found in cancer tissue and a pronounced desmoplastic reaction with deposition of type I, type III, and type IV collagen in the tumor stroma. In contrast, the noninvolved pancreas showed an intact basement membrane and a sparse stroma. The collagen type IV and laminin receptors alpha 2, alpha 3, and beta 1 integrin subunits were expressed on pancreatic cancer cells but not the alpha 6 integrin subunit normally present on epithelial cells, suggesting anchorage independence of the carcinoma cells. An increased capacity for cancer cell motility was suggested by the abundant expression of the "antiadhesive" extracellular matrix proteins, tenascin and vitronectin close to the cancer cells, and the expression of cell surface receptors such as alpha v (vitronectin-binding). Expression of the alpha 4 integrin subunit was also increased on cancer cells. CONCLUSIONS: The distribution of extracellular matrix proteins and the cell surface immune phenotype differed in pancreatic carcinoma as compared to normal pancreatic tissue. The present findings substantiate the notion that disseminated growth of highly malignant carcinomas of the pancreas reflects an invasive interaction of the tumor cells with extracellular matrix proteins of a well-established stroma. Similar findings were observed regardless of tumor histology and patient survival time.

Parathyroid hormone-related protein as a renal regulating factor. From vessels to glomeruli and tubular epithelium.

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) produce similar biological effects through the PTH/PTHrP receptor. Less is known about the physiological role of PTHrP, which was first identified as the agent of the humoral hypercalcemia of malignancy. Despite the widespread production of PTHrP in healthy individuals, the concentration of the protein is below the detectable limit of current assays, suggesting that PTHrP normally functions locally in an autocrine or paracrine manner. Thus, some differences in their biological activities have been described and they may be related to the presence of different receptors. In this regard, a second receptor that binds selectively to PTH has also been found. Recent studies have demonstrated the expression of both PTH/PTHrP receptor and protein in the renal glomeruli. Moreover, there are convincing data that support a direct role of PTH and PTHrP in modulating renal blood flow and glomerular filtration rate. This multifunctional protein, PTHrP, also has a proliferative effect on both glomerular mesangial cells and tubular epithelial cells. Increases in the expression of PTHrP have been observed in several experimental models of nephropathies, suggesting that PTHrP upregulation is a common event associated with the mechanism of renal injury and repair.

Geometric ray tracing analysis of visual acuity after laser in situ keratomileusis.

PURPOSE: Using a geometric ray tracing model, we explain the increase in visual acuity observed in myopic patients after laser in situ keratomileusis (LASIK). METHODS: This study included 37 eyes of 23 patients who underwent LASIK. All patients had myopia and a spectacle-corrected visual acuity of 0.95 or worse. Clinical tests included biometry, corneal topography, pachymetry, and refraction (with and without cycloplegia). Calculations were made by tracing rays through all the refractive surfaces of the eye based on a Le Grand-type theoretical model of the whole eye. RESULTS: Comparison of spectacle-corrected visual acuity of the eye before surgery, the size of the blur circle calculated by ray tracing, and the magnification for the ocular system facilitated a numerical criterion to assess visual acuity by geometric calculation. This criterion was applied to myopic eyes that underwent LASIK, and the maximum increase in spectacle-corrected visual acuity was predicted. An actual increase in visual acuity of approximately 40% of the predicted maximum was observed in patients. CONCLUSIONS: With geometric ray tracing, it was possible not only to obtain an estimate of the visual acuity before LASIK but also to assess the value of the maximum and probable increases in visual acuity after LASIK.

Proliferation and apoptosis in the evolution of endemic and acquired immunodeficiency syndrome-related Kaposi's sarcoma.

Kaposi's sarcoma (KS) is a multifocal lesion that occurs predominantly in the skin, most frequently in people infected with HIV-1, and that evolves through early stages (patch and plaque) to a tumor-like late stage (nodular). Both, endemic African (EKS) and AIDS-associated (AKS) KS expressed human herpesvirus 8 (HHV-8) as shown by PCR. By immunohistochemistry the expression of cellular Bcl-2 and c-myc was confined in early stages of both EKS and AKS to relatively few endothelial cells (EC) whereas in nodular KS most of spindle cells (SC) strongly expressed both genes. CD40 was usually strongly expressed in SC at all KS stages as well as in EC of non-involved tissue whereas CD40L (CD154) was not demonstrable. Fas (CD95) was moderately to weakly expressed by SC whereas p53 and Waf-1 were found in less than 5% of the SC. In both AKS and EKS at nodular stage almost no apoptotic SC were detected. In most AKS and EKS low levels of cell proliferation were seen but AKS showed consistently higher values compared to EKS. All clinical types and stages of KS showed a diploid cellular DNA content by flow cytometric analysis of microselected lesions. Thus, we conclude that KS during evolution represents diploid, probably reactive, cell proliferation, which progressively increases the expression of strong cellular and also viral (HHV-8) antiapoptotic factors.