Metabolic constraints on the body size scaling of extreme population densities.

Pest outbreaks, harmful algal blooms and population collapses are extreme events with critical consequences for ecosystems. Therefore, understanding the ecological mechanisms underlying these extreme events is crucial. We evaluated theoretical predictions on the size scaling and variance of extreme population abundance by combining (i) the generalized extreme value (GEV) theory and (ii) the resource-limited metabolic restriction hypothesis for population abundance. Using the phytoplankton data from the L4 station in the English Channel, we showed a negative size scaling of the expected value of maximal density, whose confidence interval included the predicted metabolic scaling (α = -1) supporting theoretical predictions. The role of resources and temperature in the distribution of the size-abundance pattern and residuals was well characterized by the GEV distribution. This comprehensive modelling framework will allow to elucidate community structure and fluctuations and provide unbiased return times estimates, thereby improving the prediction accuracy of the timing of the population outbreaks.

Community fluctuations and local extinction in a planktonic food web.

Determining statistical patterns irrespective of interacting agents (i.e. macroecology) is useful to explore the mechanisms driving population fluctuations and extinctions in natural food webs. Here, we tested four predictions of a neutral model on the distribution of community fluctuations (CF) and the distributions of persistence times (APT). Novel predictions for the food web were generated by combining (1) body size-density scaling, (2) Taylor's law and (3) low efficiency of trophic transference. Predictions were evaluated on an exceptional data set of plankton with 15 years of weekly samples encompassing c. 250 planktonic species from three trophic levels, sampled in the western English Channel. Highly symmetric non-Gaussian distributions of CF support zero-sum dynamics. Variability in CF decreased while a change from an exponential to a power law distribution of APT from basal to upper trophic positions was detected. Results suggest a predictable but profound effect of trophic position on fluctuations and extinction in natural communities.

Fatal cardiac and renal allograft rejection with lenalidomide therapy for light-chain amyloidosis.

We describe a patient who underwent a successful heart and kidney transplant for light-chain amyloidosis. She had an excellent hematologic response to bortezomib/dexamethasone therapy. Follow-up therapy with lenalidomide was started, and the patient quickly had a fatal allograft rejection of the heart and kidney. We present evidence to support the theory that lenalidomide, a known immunomodulator, may have stimulated the immune system and precipitated the fatal rejection episode.

Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol? / Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días?

OBJECTIVE: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices. MATERIAL AND METHODS: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images. RESULTS: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01). CONCLUSIONS: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful. In patients with joint prostheses, an increase in percentage variation above 9% obtained maximum sensitivity and negative predictive value.

Improved biovolume estimation of Microcystis aeruginosa colonies: A statistical approach.

The Microcystis aeruginosa complex (MAC) clusters many of the most common freshwater and brackish bloom-forming cyanobacteria. In monitoring protocols, biovolume estimation is a common approach to determine MAC colonies biomass and useful for prediction purposes. Biovolume (µm3 mL-1) is calculated multiplying organism abundance (orgL-1) by colonial volume (µm3org-1). Colonial volume is estimated based on geometric shapes and requires accurate measurements of dimensions using optical microscopy. A trade-off between easy-to-measure but low-accuracy simple shapes (e.g. sphere) and time costly but high-accuracy complex shapes (e.g. ellipsoid) volume estimation is posed. Overestimations effects in ecological studies and management decisions associated to harmful blooms are significant due to the large sizes of MAC colonies. In this work, we aimed to increase the precision of MAC biovolume estimations by developing a statistical model based on two easy-to-measure dimensions. We analyzed field data from a wide environmental gradient (800 km) spanning freshwater to estuarine and seawater. We measured length, width and depth from ca. 5700 colonies under an inverted microscope and estimated colonial volume using three different recommended geometrical shapes (sphere, prolate spheroid and ellipsoid). Because of the non-spherical shape of MAC the ellipsoid resulted in the most accurate approximation, whereas the sphere overestimated colonial volume (3-80) especially for large colonies (MLD higher than 300 µm). Ellipsoid requires measuring three dimensions and is time-consuming. Therefore, we constructed different statistical models to predict organisms depth based on length and width. Splitting the data into training (2/3) and test (1/3) sets, all models resulted in low training (1.41-1.44%) and testing average error (1.3-2.0%). The models were also evaluated using three other independent datasets. The multiple linear model was finally selected to calculate MAC volume as an ellipsoid based on length and width. This work contributes to achieve a better estimation of MAC volume applicable to monitoring programs as well as to ecological research.

The invariance of production per unit of food consumed in fish populations.

The amount of biomass production per unit of food consumed (P/Q) represents an important quantity in ecosystem functioning, because it indicates how efficient a population transforms ingested food into biomass. Several investigations have noticed that P/Q remains relatively constant (or invariant) across fish population that feed at the same food-type level (carnivorous/herbivorous). Nevertheless, theoretical explanation for this invariant is still lacking. In this paper, we demonstrate that P/Q remains invariant across fish populations with stable-age distribution. Three key assumptions underpin the P/Q invariant: (1) the ratio between natural mortality M and von Bertalanffy growth parameter k (M/k ratio) should remain invariant across fish populations; (2) a parameter defining the fraction of ingested food available for growth needs to remain constant across fish that feed at the same trophic level; (3) third, the ratio between length at age 0 ([Formula: see text]) and asymptotic length ([Formula: see text]) should be constant across fish populations. The influence of these assumptions on the P/Q estimates were numerically assessed considering fish populations of different lifespan. Numerical evaluations show that the most critical condition highly relates to the first assumption, M/k. Results are discussed in the context of the reliability of the required assumption to consider the P/Q invariant in stable-age distributed fish populations.

Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días? / Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol?

Objetivo: Como hay poca literatura sobre el tema, nos propusimos comparar la utilidad diagnóstica del análisis semicuantitativo versus el análisis visual en la escintigrafía de glóbulos blancos etiquetados (WBCS) para la infección osteoarticular. Se evaluaron protocolos de uno y dos días, en particular en los dispositivos ortopédicos.Material y métodos: Estudio prospectivo de 79 pacientes consecutivos con sospecha de infección osteoarticular. En todos los pacientes, la SCBM se realizó a los 30 min, 4 h, 8 h y 24 h. Las imágenes se analizaron agrupándolas en dos protocolos: protocolo de un día (los expertos evaluaron imágenes planas de 30 min, 4 h y 8 h) y protocolo de dos días (los expertos evaluaron imágenes planas de 30 min, 4 h y 24 h). Las imágenes planas se interpretaron cualitativa y semicuantitativamente y también se compararon agrupando a los pacientes con y sin dispositivos ortopédicos. Para determinar qué valor de corte de la variación porcentual podía predecir la infección osteoarticular, se calcularon múltiples valores de corte en ambos protocolos a partir del índice de Youden. Tres lectores ciegos analizaron las imágenes.Resultados: Comparando el diagnóstico final, el análisis visual del protocolo de un día proporcionó mejores resultados con una sensibilidad del 95,5%, una especificidad del 93% y una precisión diagnóstica del 93,7% (p < 0,01) que el protocolo de dos días con valores del 86,4%, 94,7% y 92,4%, respectivamente (p < 0,01). Para el análisis semicuantitativo, el protocolo de un día también obtuvo mejores resultados con una sensibilidad del 72,7%, una especificidad del 78,9% y una precisión del 77,2% (p < 0,01) que el protocolo de dos días (sin resultados significativos; p = 0,14), especialmente en el grupo de pacientes con aparatos ortopédicos (sensibilidad del 100%, especificidad del 79,5% y precisión del 82,7%; p < 0,01)

Objective: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices.Material and methods: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images.Results: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01).Conclusions: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful

Furazolidone, amoxycillin, bismuth triple therapy for Helicobacter pylori infection.

BACKGROUND: Metronidazole-resistant Helicobacter pylori are generally the rule in developing countries such as Colombia. Developing countries need an effective, simple and inexpensive non-metronidazole therapy for H. pylori infection. AIM: To evaluate the combination of bismuth, furazolidone and amoxycillin for the treatment of H. pylori infection in Colombia. METHODS: Thirty patients with histologically documented H. pylori infection received the combination of bismuth subcitrate 240 mg b.d., furzolidone 100 mg q.d.s. and amoxycillin 500 mg q.d.s. for 14 days. Four or more weeks after ending therapy patients were re-endoscoped and gastric biopsies were obtained and examined using the Genta stain. Each slide was scored for presence, absence and density of H. pylori, active and chronic inflammation, intestinal metaplasia, erosions and atrophy. Cure was defined as the absence of H. pylori. RESULTS: All patients completed the course of therapy. Twenty-five patients were cured (86%, 95% CI: 65-94%). Mild, well-tolerated side-effects were reported by six patients (20%). CONCLUSIONS: This combination of bismuth, furazolidone and amoxycillin fulfills the criteria for successful H. pylori therapy and appears particularly well suited for developing countries since it is simple, inexpensive and effective. Furazolidone-containing therapies may become especially useful in the face of a world-wide increase in H. pylori resistance to metronidazole and macrolides.

Partial left ventriculectomy: which patients can be expected to benefit?

BACKGROUND: Although some patients with end-stage heart disease will benefit from a partial left ventriculectomy, no criteria have been found for identifying this group preoperatively. Our experience with partial left ventriculectomy at two institutions-the Texas Heart Institute in Houston, TX, USA, and Dedinje Cardiovascular Institute in Belgrade, Yugoslavia-showed a higher survival rate and better postoperative myocardial function in the Yugoslavian patients. METHODS: We reviewed data from 42 patients (21 at each center) who had idiopathic cardiomyopathy, a left ventricular end-diastolic dimension of more than 70 mm, wall thickness of 1 cm or greater, and New York Heart Association class III or IV symptoms. The only significant difference in preoperative status between the two groups was duration of symptoms. Histologic specimens, blinded as to origin, were graded with regard to myocyte hypertrophy, cytoplasmic vacuolation, and fibrosis. Computer-assisted myocyte and nuclear morphometry was also performed. RESULTS: Immediately postoperatively, there were no significant intergroup differences in the reduction in cardiac dimension or in corrections of mitral regurgitation. During 6-month follow-up, however, the Texas Heart Institute patients had a lower cardiac index (1.8 versus 3.0 L x min(-1) x m(-2); p = 0.001) and left ventricular ejection fraction (24% versus 34%; p = 0.006) than the Dedinje Cardiovascular Institute patients. The Texas Heart Institute patients differed from the Dedinje Cardiovascular Institute patients in the degree of severe or moderate changes in myocyte hypertrophy (90% versus 29%; p = 0.0003) and fibrosis (71% versus 29%; p = 0.006), as well as in the measurements of median myocyte diameter (35 +/- 7 microm versus 27 +/- 4 microm; p = 0.0002) and median nuclear size (15 +/- 4 microm versus 12 +/- 2 microm; p = 0.0029). CONCLUSIONS: In the Texas Heart Institute patients, the significant intergroup difference in clinical outcome may have been related to increased myocyte hypertrophy and fibrosis. Further studies should be performed to determine the usefulness of these criteria in selecting patients for partial left ventriculectomy.

[Evaluation of clinical competence. The immediate future of nursing]. / Evaluar la competencia clínica. Futuro inmediato para enfermería.

In this article, the authors analyze the concept of professional competence and they describe some of the methods destined to be used in the evaluation of said competence in nursing professionals. The authors describe different levels of professional performance to which an evaluation may be carried out according to the conceptual model developed by Miller. Special emphasis is placed on the third level of evaluation which is based on simulations of professional practice whose protagonists are the so called simulated or role-playing/standardized sick. One type of very novel evaluation test is the Objective Structured Clinical Examination (OSCE) which makes use of, besides the simulated or role-playing/standardized sick, other mediums such as manikins, standardized tests, open-ended short answer questions, etc. This is one of the most complete clinical competence evaluation methods currently available, although one should not forget that this evaluation is carried out in a simulated, laboratory, setting.

Competition drives clumpy species coexistence in estuarine phytoplankton.

Understanding the mechanisms that maintain biodiversity is a fundamental problem in ecology. Competition is thought to reduce diversity, but hundreds of microbial aquatic primary producers species coexist and compete for a few essential resources (e.g., nutrients and light). Here, we show that resource competition is a plausible mechanism for explaining clumpy distribution on individual species volume (a proxy for the niche) of estuarine phytoplankton communities ranging from North America to South America and Europe, supporting the Emergent Neutrality hypothesis. Furthermore, such a clumpy distribution was also observed throughout the Holocene in diatoms from a sediment core. A Lotka-Volterra competition model predicted position in the niche axis and functional affiliation of dominant species within and among clumps. Results support the coexistence of functionally equivalent species in ecosystems and indicate that resource competition may be a key process to shape the size structure of estuarine phytoplankton, which in turn drives ecosystem functioning.

Relación entre el transporte y las características nutricionales de la carne porcina para consumo humano en el valle de aburrá (colombia) / Relationship between transport and nutritional characteristics of pork meat for human consumption in the valle de aburrá (colombia)

RESUMEN La carne de cerdo se considera fuente de alto valor nutritivo por su alto contenido de proteína; sin embargo, su transporte representa un eslabón crítico, por cuanto genera pérdidas económicas, cuando se producen alteraciones en el bienestar animal que repercuten en los parámetros nutricionales, disminuyen la capacidad de retención de agua y ocasionan pérdidas de proteína. El objetivo de este estudio fue relacionar las características de los transportes con las características nutricionales de la carne porcina destinada a consumo humano en el Valle de Aburrá (Antioquia, Colombia) en 2017. Se visitaron tres plantas de sacrificio del Valle de Aburrá con muestreo probabilístico estratificado por planta y afijación igual, obteniendo información de 338 animales. Se analizaron los parámetros nutricionales de las muestras cárnicas, así como variables sociodemográficas, de infraestructura, bienestar animal y prácticas de conducción de los transportistas. Se realizaron pruebas de ji-cuadrado (χ 2) para variables cualitativas dicotómicas, regresión logística para variables cualitativas politómicas y U de Mann-Whitney para variables cuantitativas. Se encontró asociación entre varios de los parámetros indagados con valores p estadísticamente significativos (p = 0,000; así, no tener suministro de agua permanente para los animales incrementa en 46,55 veces (IC 18,08 - 120,07) la posibilidad de presentar carnes nutricionalmente inadecuadas. Se concluye que factores como la falta de suministro de agua a los cerdos, el mal estado de pisos y separadores, la deficiente capacitación de los transportistas, la falta de supervisión a los animales, no tener el certificado técnico-mecánico y la velocidad promedio de 80 km/h, se asocian con la generación de productos cárnicos nutricionalmente inadecuados.

ABTRACT Pork meat is considered a source of high nutritional value due to its high protein content, however, transport is a critical link to generate economic losses by producing alterations in animal welfare, which have an impact on nutritional parameters, decreasing the capacity of water retention, and generating protein losses. The objective of this study was to relate the characteristics of transport, with the nutritional characteristics of pork for human consumption in the Valle de Aburrá (Antioquia, Colombia) in 2017. In this location, three slaughterhouses were visited with probabilistic sampling stratified by plant and equal affixation, obtaining information from 338 animals. The nutritional parameters of the meat samples and sociodemographic variables, infrastructure, animal welfare and driving practices of the transporters were analyzed. ji-square (χ 2) tests were performed for dichotomous qualitative variables, logistic regression for qualitative polytomous variables and Mann-Whitney U test for quantitative variables. An association was found between several of the parameters investigated with statistically significant p values (p = 0,000), where, having no permanent water supply for the animals increases in 46.55 times (IC 18.08 - 120.07) the possibility of presenting nutritionally inadequate meats. It was concluded that factors such as lack of water supply to pigs, poor condition of the floors and separators, lack of training in transporters, lack of supervision of animals, lack of mechanical technical certification and average speed of 80 km/h are associated with the generation of nutritionally inadequate meat products.

Intensity of infection in AIDS-related intestinal microsporidiosis.

To quantify intensity of infection in AIDS-related microsporidiosis, 20 patients with known microsporidiosis submitted stools for quantitative spore counts after staining with a calcofluor white stain. Nine patients collected stools for 24 h, for assessment of daily spore excretion, stool-to-stool variation in spore excretion, and patient-to-patient variation in intensity of infection. The number of organisms seen in small bowel biopsy specimens from 7 patients was compared with quantitative fecal spore excretion. Fecal spore concentration in 20 patients ranged from 4.5x105 to 4.4x108 spores/mL of stool. There was a strong correlation between fecal spore excretion and duodenal biopsy spore counts (r=.82; P<.024). Microsporidium infections in AIDS patients can be quantified by counting spores in stool and by small bowel biopsy. Variations in intensity of infection from patient to patient are great and are similar to those in AIDS-related Cryptosporidium infection.

Histologic assessment of Helicobacter pylori status after therapy: comparison of Giemsa, Diff-Quik, and Genta stains.

To compare the Giemsa, Diff-Quik, and Genta stains for detection of Helicobacter pylori in gastric biopsy specimens, we stained, coded, and randomized slides, which were then independently reviewed by two pathologists and one trainee. H. pylori was graded from 0 (absent) to 5 (maximal intensity). Negative cases were from recently cured patients to ensure that a background of chronic inflammation was present. The time required to complete the evaluation was tabulated. The pathologists interpreted 72 H. pylori-negative slides, of which 1 (1.3%), 2 (3%), and 3 (4%) were scored positive (each with the score of 1) with Diff-Quik, Genta, and Giemsa stains, respectively (P = ns). Of the 128 H. pylori-positive slides, 5 (4%) had false-negative results with Diff-Quik, 8 with Genta (6%), and 14 with Giemsa stains( 11%). No Grade 2 slides were missed by Genta or Diff-Quik stains, but 3 of 20 were missed by Giemsa stain. The combination of hematoxylin and eosin and Diff-Quik provides accuracy similar to that of the Genta stain but requires more processing time. No stain was excellent after therapy for detecting one or two bacteria per slide; this finding emphasizes the need for obtaining multiple biopsy specimen to exclude failure of H. pylori therapy.

Mast cell involvement in gastritis with or without Helicobacter pylori infection.

BACKGROUND & AIMS: Mast cells are initiators and regulators of inflammation, but their role in the human stomach remains unclear. Therefore, the extent and distribution of mast cell involvement in gastritis with or without Helicobacter pylori infection was investigated. METHODS: Mapped biopsy specimens from 17 H. pylori-positive and 20 H. pylori-negative subjects were examined. Sections were assessed for infection and inflammation and stained with anti-human mast cell tryptase to count mucosal and epithelial mast cells. Density of mast cells in different gastric compartments, their response to infection treatment, and their relationship with other inflammatory cells were evaluated. Mast cell degranulation was evaluated by electron microscopy. RESULTS: Mast cell density was significantly greater in the mucosa with gastritis, with or without H. pylori infection, than in the mucosa of noninfected normal subjects. In the antrum, density was much greater in H. pylori-infected peptic ulcer subjects than in the other gastritis groups. It also correlated significantly with the intensity of inflammation. Mast cell degranulation was demonstrated by electron microscopy in H. pylori-infected mucosa. Mast cell density in ulcer patients decreased significantly after cure of H. pylori infection. CONCLUSIONS: Mast cells may be important effector cells in the pathogenesis of gastritis, especially in H. pylori-associated peptic ulcer.

Cure of Helicobacter pylori infection improves gastric acid secretion in patients with corpus gastritis.

BACKGROUND: For more than 30 years it has been known that gastric acid secretion is inversely related to the extent and severity of corpal gastritis. We therefore evaluated the effect of cure of Helicobacter pylori infection on basal and pentagastrin-stimulated acid secretion. METHODS: Basal acid output (BAO) and maximal acid output (MAO) were assessed in 11 H. pylori-infected dyspeptic patients (8 women and 3 men; mean age, 28 years) before and after successful anti-H. pylori therapy. RESULTS: The gastritis index was significantly lower after therapy and was associated with an increase in both BAO and MAO after cure of the H. pylori infection (BAO from 0.3 mmol/h and MAO from 4.8 mmol/h to 19 mmol/ h). Basal and stimulated acid concentrations also increased (29.1 +/- 36.6 to 54 +/- 31 mmol/l and 72.5 +/- 46 to 120.1 +/- 30 mmol/l, respectively, for basal and stimulated acid concentrations; P < 0.05 for peak and MAO, P = 0.07 for BAO). CONCLUSION: Gastric acid secretion increased into the normal range after successful treatment of H. pylori infection, suggesting that gastric function can recover to normal or almost normal after cure of H. pylori infection.

Immunohistochemistry of matrix metalloproteinases and their inhibitors in thoracic aortic aneurysms and aortic valves of patients with Marfan's syndrome.

BACKGROUND: Thoracic aortic aneurysms (TAAs) and valvular insufficiency, the main cardiovascular lesions in Marfan's syndrome, are associated with destruction of connective tissue; however, their pathogenesis remains unclear. METHODS AND RESULTS: To test the hypothesis that changes in the activity of the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are responsible for the damage to connective tissue in these lesions, histochemical studies of the immunoreactivity (IR) for MMPs and their tissue TIMPs (MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, and TIMP-2) were made in TAAs (n = 7) and aortic valves (n = 5) from 7 patients with Marfan's syndrome. All TAAs showed cystic medial necrosis (CMN), with loss of elastic fibers and smooth muscle cells. Extensive areas of myxoid change were found in all aortic valves. Areas of CMN showed no IR for any MMPs or TIMPs. The IR of smooth muscle cells at the borders of areas of CMN was stronger for all MMPs, especially MMP-2 and MMP-9, than in other regions. The surfaces of disrupted elastic fibers showed IR for MMP-2 and MMP-9. Areas of myxoid change showed similar but less pronounced alterations. CONCLUSIONS: We hypothesize that the defect in fibrillin-1 in Marfan's syndrome leads to (1) formation of elastin that is abnormally aggregated and more easily degraded by MMPs than is normal elastin, (2) upregulation of the synthesis of MMPs, (3) progressive destruction of connective tissue by these enzymes, and (4) development of TAAs and valvular lesions.

Adherence of Helicobacter pylori to areas of incomplete intestinal metaplasia in the gastric mucosa.

BACKGROUND & AIMS: Helicobacter pylori is not usually found in areas of intestinal metaplasia. Thus, the development of intestinal metaplasia has been viewed as a mechanism by which the stomach eliminates H. pylori. The aim of this study was to evaluate the frequency of H. pylori adherence to intestinal metaplasia in different populations. METHODS: Mapped gastric biopsy specimens from 378 H. pylori-positive subjects from various geographical regions were examined. Intestinal metaplasia was typed by staining with periodic acid-Schiff/alcian blue and high-iron diamine/alcian blue. RESULTS: In 32 patients, H. pylori was found in intimate contact with intestinal metaplasia. This was documented by electron microscopy. All areas of intestinal metaplasia showing adherence contained sulfomucins and had no brush border. Posttreatment biopsy specimens from 4 patients whose infection was not cured showed persistence of H. pylori in intestinal metaplasia. CONCLUSIONS: These patients may have a strain of H. pylori with unusual adhesion characteristics, or their type of intestinal metaplasia may have biochemical properties that make it hospitable for H. pylori. The exclusive association of H. pylori adherence with incomplete intestinal metaplasia (a putative precursor of carcinoma) and its greater frequency in Koreans (a population at risk for gastric cancer) suggest that this phenomenon may play a role in the hypothetical sequence metaplasia > dysplasia > carcinoma.

[The main health problems according to patients' opinion]. / Los principales problemas de salud según la opinión de los usuarios.

OBJECTIVE: To know the health problems or diseases that patients of 2 basic health areas (BHA) assess as the most important for Spanish population and for themselves; to know if any relation exists between these problems and their existence in the family or social patients' environment. DESIGN: An observational cross-sectional and descriptive study. SETTING: Four clinics of the BHA Sant Josep (L'Hospitalet de Llobregat) and 2 clinics of the BHA Sant Martí (Barcelonés).Patients. The sample consists of 360 patients aged above 26 years who attended clinics for some health problem. Participants were chosen by a randomised systematic sampling, from May to October 2000. MEASUREMENTS AND MAIN RESULTS: Data were gathered from a questionnaire of ten items. According with the participants, the main problems for Spanish population and for themselves were: cancer, cardiovascular diseases and AIDS. Cancer (58,61%; 95% CI, 53,53-63,69) and AIDS (15,27%; 95% CI, 11,56-18,98) are the problems pointed out as research priorities. The aparato locomotor (22,10%; 95% CI, 17,82-26,38), hypertension (14,74%; 95% CI, 11,08-18,40) and diabetes (13,14%, 95% CI, 9,66-16,62) are the main problems suffered by the surveyed. Cancer is the disease that more participants' relatives suffered. CONCLUSIONS: Cancer and cardiovascular diseases are the pathologies that cause more concern among the surveyed and these are the diseases which mostly affect their relatives and relationships. Nevertheless their worry for the AIDS don't show their immediate reality. Frequently, patients don't recognize the health problem that motivated their visit as a real disease.