A 3D mathematical model of coupled stem cell-nutrient dynamics in myocardial regeneration therapy.

Stem cell therapy is a promising treatment for the regeneration of myocardial tissue injured by an ischemic event. Mathematical modeling of myocardial regeneration via stem cell therapy is a challenging task, since the mechanisms underlying the processes involved in the treatment are not yet fully understood. Many aspects must be accounted for, such as the spread of stem cells and nutrients, chemoattraction, cell proliferation, stages of cell maturation, differentiation, angiogenesis, stochastic effects, just to name a few. In this paper we propose a 3D mathematical model with a free boundary that aims to provide a qualitative description of some main aspects of the stem cell regenerative therapy in a simplified scenario. The paper mainly focuses on the description of the shrinking of the necrotic core during treatment. The stem cell and nutrients dynamics are described through coupled reaction-diffusion problems. Proliferation, chemoattraction, tissue regeneration and nutrient consumption are included in the model.

Reproductive Behavior of Copitarsia uncilata (Lepidoptera: Noctuidae).

Copitarsia sp. (Hampson) (Lepidoptera: Noctuidae: Cuculliinae) is a quarantine pest in different countries and affects diverse crops of economic importance in South America. The development of ethological control strategies is an important issue that requires knowing the reproductive behavior of the species involved. Therefore, the aim of this study was to establish the reproductive behavior of Copitarsia uncilata (Burgos & Leiva) and to evaluate the attractiveness of synthetic pheromone compounds under laboratory conditions. Observations of nocturnal reproductive behavior of males and females were performed for 7 days in order to register the courtship, mating, and oviposition time. Once the period of the highest reproductive activity was identified, flight behavior and attraction of virgin males were evaluated in a wind tunnel towards synthetic compounds previously reported as commercial pheromones for Copitarsia species, namely (Z)-tetradec-9-enyl acetate (Z9-14Ac), (Z)-tetradec-9-enol (Z9-14OH), and their mixture (Z9-14Ac + Z9-14OH at 4:1 ratio), in comparison with virgin females and clean air flow. We observed that reproductive behavior occurs during the first third of the scotophase and begins on the second day after adult emergence. Highest proportion of courtship and mating occurs on days 2 and 3 after emergence, and oviposition starts the night immediately after the first mating. Wind tunnel assessments showed that males were highly attracted to calling females compared with the blend of synthetic pheromone compounds, with 89% and 12% of males landing at the source, respectively. Moreover, males also showed a low response to the isolated compounds (Z9-14Ac 14% and Z9-14OH 4%).

Mercury in Populations of River Dolphins of the Amazon and Orinoco Basins.

In the Amazon and Orinoco basins, mercury has been released from artisanal and industrial gold mining since the Colonial time, as well as a result of deforestation and burning of primary forest, that release natural deposits of methyl mercury, affecting the local aquatic vertebrate fauna. This study reports the presence of mercury in river dolphins' genera Inia and Sotalia. Mercury concentrations were analysed in muscle tissue samples collected from 46 individuals at the Arauca and Orinoco Rivers (Colombia), the Amazon River (Colombia), a tributary of the Itenez River (Bolivia) and from the Tapajos River (Brazil). Ranges of total mercury (Hg) concentration in muscle tissue of the four different taxa sampled were: I. geoffrensis humboldtiana 0.003-3.99 mg kg-1 ww (n = 21, Me = 0.4), I. g. geoffrensis 0.1-2.6 mg kg-1 ww (n = 15, Me = 0.55), I. boliviensis 0.03-0.4 mg kg-1 ww (n = 8, Me = 0.1) and S. fluviatilis 0.1-0.87 mg kg-1 ww (n = 2, Me = 0.5). The highest Hg concentration in our study was obtained at the Orinoco basin, recorded from a juvenile male of I. g. humboldtiana (3.99 mg kg-1 ww). At the Amazon basin, higher concentrations of mercury were recorded in the Tapajos River (Brazil) from an adult male of I. g. geoffrensis (2.6 mg kg-1 ww) and the Amazon River from an adult female of S. fluviatilis (0.87 mg kg-1 ww). Our data support the presence of total Hg in river dolphins distributed across the evaluated basins, evidencing the role of these cetaceans as sentinel species and bioindicators of the presence of this heavy metal in natural aquatic environments.

The Reference Site Collaborative Network of the European Innovation Partnership on Active and Healthy Ageing.

Seventy four Reference Sites of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) have been recognised by the European Commission in 2016 for their commitment to excellence in investing and scaling up innovative solutions for active and healthy ageing. The Reference Site Collaborative Network (RSCN) brings together the EIP on AHA Reference Sites awarded by the European Commission, and Candidate Reference Sites into a single forum. The overarching goals are to promote cooperation, share and transfer good practice and solutions in the development and scaling up of health and care strategies, policies and service delivery models, while at the same time supporting the action groups in their work. The RSCN aspires to be recognized by the EU Commission as the principal forum and authority representing all EIP on AHA Reference Sites. The RSCN will contribute to achieve the goals of the EIP on AHA by improving health and care outcomes for citizens across Europe, and the development of sustainable economic growth and the creation of jobs.

Prediction of CO maximum ground level concentrations in the Bay of Algeciras, Spain using artificial neural networks.

The region of the Bay of Algeciras is a very industrialized area where very few air pollution studies have been carried out. The main objective of this work has been the use of artificial neural networks (ANNs) as a predictive tool of high levels of ambient carbon monoxide (CO). Two approaches have been used: multilayer perceptron models (MLPs) with backpropagation learning rule and k-Nearest Neighbours (k-nn) classifiers, in order to predict future peaks of carbon monoxide. A resampling strategy with twofold cross-validation allowed the statistical comparison of the different topologies and models considered in the study. The procedure of random resampling permits an adequate and robust multiple comparisons of the tested models and allow us to select a group of best models.

[Clinical manifestations and diagnostic delay in Wolfram's syndrome]. / Manifestaciones clínicas y retraso diagnóstico en el síndrome de Wolfram.

UNLABELLED: Wolfram's syndrome (SW): diabetes mellitus (DM), diabetes insipidus (DI), blindness and deafness, is multiorganic, hereditary and uncommon. Mitochondrial dysfunction damages the oxidative pathway. OBJECTIVE: To analyze the clinical characteristics, diagnostic delay in constituent diseases and early diagnostic impact over morbidity-mortality. MATERIAL AND METHODS: Descriptive retrospective study of 23 Spanish patients with SW. Different clinical entities analysis, onset age, lapse of time before diagnosis, morbidity-mortality causes, prescribed therapy and consanguinity between parents. RESULTS: Components prevalence: DM and optic atrophy (AO), 100%; auditory impairment, 95.65%; DI, 82.6%; gonadal atrophy, 75% in men; menstrual disorders, 87.5% in women. Other diseases: urinary tract, neurologic and heart disorders. CONCLUSIONS: Most of the patients will develop almost all the complications. Juvenile DM in association with AO is its best diagnostic criteria. Early therapy should delay progression and control mortality causes.

Eficacia y estabilidad del proceso de amonificación como tecnología de descontaminación de aflatoxina B1 en arroz (Oriza sativa) / Efficacy and stability of ammoniation process as aflatoxin B1 decontamination technology in rice

Rice, a cereal widely used in Venezuela for human and animal nutrition, is susceptible to aflatoxin contamination in the field and during storage. Therefore, the goal of this research was the evaluation of the efficacy and permanence of the ammoniation process through high pressure/high temperature (HP/HT) and atmospheric pressure/moderate temperature (AP/MT) conditions applied to rice samples artificially contaminated with aflatoxin B1. For this purpose a 2k design was drawn up considering the temperature, the rice moisture and the process time as variables. Under both sets of conditions, aflatoxin B1 concentration was reduced in a range of 90 per cent to 100 per cent. After in vitro stomach digestion simulation, toxin reversion ranged from 0 per cent to 19 per cent. In conclusion, the process efficacy and permanence were achieved through the use of high temperature and long process time for both sets of conditions (HP/HT and AP/MT), respectively.

Colombian study to assess the use of noninvasive determination of endothelium-mediated vasodilatation (CANDEV). Normal values and factors associated.

The endothelium plays a critical role in vascular homeostasis. Recently, a noninvasive method has been developed to assess flow mediated vasodilatation of the brachial artery (FMD). This test is remarkably stable overtime but no clear set of normal values has been developed. The purposes of our study were to evaluate the accuracy and reproducibility and to identify a set of normal values of FMD. We included 253 normotensive healthy volunteers from three Colombian cities (mean age: 38.2 years; 33% were women). All subjects underwent ultrasound evaluation of endothelial and smooth muscle function. Flow mediated vessel diameter change was measured by two independent observers. The interobserver Lin's concordance correlation coefficient was 0.88% (95% CI: 0.82, 0.94) and there was no evidence of systematic difference between the two measurements (mean difference of -0.30% with limits of agreement of -4.48 to 3.87). Mean %FMD was 11.98% (95% CI: 11.36, 12.61), 13.32% (95% CI: 12.39, 14.25) in women and 11.32% (95% CI: 10.52, 12.13) in men. Subjects with no cardiovascular risk factors had a mean %FMD of 13.74% (95% CI: 13.14, 14.35), in contrast to a mean of only 7.40% (95% CI: 4.33, 9.91) in those with at least one risk factor. A %FMD cut point of 10.4 had a sensitivity of 71.2% and an specificity of 77.2% to identify subjects with at least one cardiovascular risk factor. Using this cut point, endothelial dysfunction was 3.13 times more frequent in subjects with than in subjects without cardiovascular risk factors (95% CI: 2.30, 4.25). In addition, obesity, smoking and hypercholesterolemia were the modifiable risk factors with largest independent significant reduction effects on %FMD. FMD measurements can be made with high accuracy and precision, and a cut point of 10.4% is useful to discriminate between subjects with and without cardiovascular risk factors, and can be recommended as a screening test for the detection of patients at risk of CVD.

Factores de riesgo en enfermedad cerebro vascular isquémica en paciente menores de 45 años / Risk factors of stroke in young people

Un Evento Cerebro Vascular (ECV) es un suceso dramático en un paciente joven, al considerar la discapacidad, el impacto social y los altos costos en procesos de rehabilitación. Por lo anterior, se han creado programas de prevención para los factores de riesgo implicados en la presentación de éstos. Con este trabajo, se pretende realizar una revisión teórica de los factores de riesgo, etiologías implicadas en la presentación de un ECV, además se presenta un informe de las historias clínicas de los pacientes que consultaron al Hospital San Juan de Dios, en el período comprendido entre enero de 1995 y junio del 2000, con el fin de describir los factores de riesgo, enfermedades asociadas en esta población y aportar una información preliminar

Use of optical coherence tomography (OCT) and indirect ophthalmoscopy in the diagnosis of macular edema in diabetic patients.

OBJECTIVES: To evaluate the use of Optical Coherence Tomography (OCT) in the diagnosis of macular edema (ME) in diabetic patients in comparison to indirect ophthalmoscopy (IO) and, in addition, to study the characteristics of these patients. METHODS: 165 patients were randomly selected to join the study in 1998. Ophthalmological, clinical and laboratory examinations were performed for all these patients. RESULTS: Diabetic retinopathy was identified in 143 eyes (44.7%) and ME in 58 (18.3% of the total and 40.5% of the patients with retinopathy). 82.7% (48) of the eyes with ME could be diagnosed with OCT, against 62.0% (36) with IO. Haemoglobin A1c was the only variable that showed a significant association with ME, when compared to control (p < 0.05). Retinopathy was associated with the presence of nephropathy (p = 0.01) and neuropathy (p = 0.001), but ME was not (NS for both). 68% of patients without ME had a visual acuity of more than 50%. CONCLUSIONS: OCT is a new method that can help the evaluation of ME in diabetic patients. It can be used not only to diagnose the lesion, but also to follow up the patients during treatment. High levels of haemoglobin A1c might be associated with the presence of ME. Diabetic complications (nephropathy and neuropathy) are associated with retinopathy but not with macular edema.

Thyrotropin-like immunoreactivity in the developing chicken retina.

In this paper we analysed the presence and localisation of thyrotropin during retinal development in Gallus domesticus. Specific thyrotropin-like immunohistochemical staining was observed from the beginning of the second incubation week to one day post-hatching in chicken retina. Thyrotropin is a 28.3 KDa glycoprotein, synthesised by the anterior pituitary gland, and it is implicated in the stimulation of the synthesis and release of thyroid hormones. Until now, the action of thyrotropin has been established exclusively in hormonal terms. Recently, this glycoprotein has been localised in synaptic processes in the human retina by using a specific antiserum (Fdez-Trujillo et al., 1995). To the best of our knowledge this report is the first time that thyrotropin has been immunocytochemically demonstrated in the chicken retina. The pattern of thyrotropin-like immunoreactivity suggests that this glycoprotein could act as modulator of synaptic transmission, but it may also play a much broader role in regulating trophic functions.

Genetic diversity and population structure of Vibrio cholerae.

Multilocus enzyme electrophoresis (MLEE) of 397 Vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from Mexico and Guatemala, identified 279 electrophoretic types (ETs) distributed in two major divisions (I and II). Linkage disequilibrium was demonstrated in both divisions and in subdivision Ic of division I but not in subdivision Ia, which includes 76% of the ETs. Despite this evidence of relatively frequent recombination, clonal lineages may persist for periods of time measured in at least decades. In addition to the pandemic clones of serogroups O1 and O139, which form a tight cluster of four ETs in subdivision Ia, MLEE analysis identified numerous apparent clonal lineages of non-O1 strains with intercontinental distributions. A clone of serogroup O37 that demonstrated epidemic potential in the 1960s is closely related to the pandemic O1/O139 clones, but the nontoxigenic O1 Inaba El Tor reference strain is not. A strain of serogroup O22, which has been identified as the most likely donor of exogenous rfb region DNA to the O1 progenitor of the O139 clone, is distantly related to the O1/O139 clones. The close evolutionary relationships of the O1, O139, and O37 epidemic clones indicates that new cholera clones are likely to arise by the modification of a lineage that is already epidemic or is closely related to such a clone.

[Dose-effect of the administration of ferrous fumarate in aged persons with iron deficiency]. / Dosis efecto de la administración de fumarato ferroso en personas ancianas con deficiencia de hierro.

BACKGROUND: Anemia is the most prevalent hematological problem in elderly persons, affecting 14% of the males and 6% of the females of the population over 60 years of age in Mexico City. OBJECTIVE: To determine the effect produced by the prolonged administration of ferrous fumarate in elderly persons with iron deficiency. METHOD: In a population of 178 subjects, aged between 65 to 100 years, iron deficiency was diagnosed in 51 (28.6%), who had serum iron concentrations below 80 micrograms/dL for men and 60 micrograms/dL for women, but only 21 patients (11.8%), accepted to participated in the study. The response to a 6 months oral administration of ferrous fumarate were studied with a daily oral dose of 5 mg/kg of elemental iron. The patients were classified in 3 groups according to the abnormal parameters of iron metabolism (group 1 = 10.9% anemia, group 2 = 28.0% and group 3 = 63.0% anemia). RESULTS: The efficacy of treatment was evaluated by quantification of the changes occurred in serum iron concentrations, hemoglobin, ferritin and transferrin saturation index, at 0, 30, 90 and 180 days of treatment. This study showed that the treatment of oral ferrous fumarate in elderly patients with iron deficiency, produces a quantifiable improvement in measures of iron parameters within 6 months. CONCLUSIONS: The results of this study suggest the usefulness of prolonged treatment with ferrous fumarate in elderly patients with iron deficiency, to avoid therapeutic failure as a consequence of non-compliance as is common in elderly patients.

[Medical care costs for HIV-positive and AIDS patients in four hospitals in Santiago, Chile]. / Costos de atención de pacientes seropositivos VIH y SIDA en cuatro hospitales de Santiago de Chile.

BACKGROUND: Medical care of HIV infected and AIDS patients may represent an important economical burden for public hospitals. AIM: To assess direct and indirect costs of medical care for HIV infected and AIDS patients in public hospitals of the Metropolitan Region of Chile. MATERIAL AND METHODS: Between August 1994 and February 1995, information about outpatient and hospitalized medical care of 417 HIV infected patients was gathered (representing approximately 16% of the seropositive population). Patients were divided as having or not having AIDS. The latter were those included in groups I, II, III and category C2 of group C (group 4). The cost of medications, procedures and examinations of these patients was calculated. RESULTS: Thirty six percent of studied patients had AIDS. The annual cost of care for AIDS patients was US$3760 compared to US$1450 for HIV infected patients without AIDS. Medications represented 75% and 65% of total costs in patients with and without AIDS respectively. The figures for examinations and procedures were 17% and 22% and for medical attentions were 7.5% and 8.8% respectively. CONCLUSIONS: Medical care of patients with AIDS has higher costs than that of HIV infected patients without AIDS. Thus, the retardation of the progression of the disease would have social, humanitarian and economical benefits. Our costs are similar to those of other countries with a similar level of economic development.

Study of the distribution of glycosidic residues in eccrine sweat glands, with special reference to the content of sialic acid.

We used a group of lectins (Con-A, WGA, SBA, DBA, RCA-1, UEA-1), enzymes (neuraminidase digestion) and conventional histochemical techniques (periodic acid-Schiff reaction and reduction-saponification-Schiff reaction) in order to detect the presence of glycoproteins rich in sialic and neuraminic acids in the human eccrine sweat glands. Using both identification systems, our results showed an abundant secretion, rich in C8Oxi-acylated sialic acid.

The neural marker neuron-specific enolase in the development of embryo chicken retina: a morphological description.

The localisation and distribution of Neuron-specific enolase is reported in the avian Gallus domesticus retinal development by using immunocytochemistry. Neuron specific enolase was found to be present from the early days of incubation to the post-hatch period. The results obtained using this neural marker showed the development pattern of the distribution and the sequence of differentiation of the retinal neural structures. Like the finding of the members of the phylogenetic scale, this enzyme should prove to be a useful tool in the neural development of the chicken retina.

[A new classification of lower infarcts with important prognostic significance]. / Uma nueva clasificación de los infartos inferiores con importante significación pronóstica.

BACKGROUND: The initial therapy of acute myocardial infarction is often determined by the electrocardiogram. OBJECTIVE: To evaluate a classification of inferior myocardial infarctions according to the first electrocardiogram. DESIGN AND SETTING: Prospective study in a coronary care unit. PATIENTS: 116 patients admitted due to a first acute myocardial infarction of the inferior wall. METHODS: "Type 1" electrocardiogram was defined as ST segment elevation without distortion of the QRS. Patients were considered "type 2" when, besides ST segment elevation, they presented a distortion of the terminal portion of the QRS complex in two inferior leads. MAIN RESULTS: Twenty-nine patients (25%) were considered "type 2". These patients were older and had worse Killip class than "type 1". The mortality rate was 1.2% in "type 1", and 24.1% in "type 2" (p = 0.0002). After multivariate analysis, which included Killip class, age, smoking, type of electrocardiogram and fibrinolysis, the type of electrocardiogram remained significantly predictive of death (p = 0.014). CONCLUSIONS: We conclude that "type 2" electrocardiogram is an independent predictor of adverse outcome in inferior infarctions. Further investigation is needed concerning its implications in the clinical management of these patients, although reperfusion therapy is warranted.

[Infections caused by enteropathogenic Escherichia coli]. / Infecciones por Escherichia coli enteropatógena.

Escherichia coli strains currently recognized to cause human diarrhea can be distinguished on the basis of pathogenic mechanism and separated into five categories: enterotoxigenic (ETEC), enteroinvasive (EIEC), enterohemorrhagic (EHEC), enteroaggregative (EAggEC) and enteropathogenic (EPEC). EPEC is a bacterial pathogen that causes diarrhea in infants, particularly in developing countries. The purpose of this review is to summarize recent advances in the understanding of EPEC pathogenesis and the contribution of Mexican investigators to the knowledge of this pathogen.

[Usefulness of cerebral biopsy in focal cerebral lesions in patients with human immunodeficiency virus infection]. / Utilidad de la biopsia cerebral en las lesiones cerebrales focales en pacientes con infección por el virus de la inmunodeficiencia humana.

Brain mass lesions (BML) occurred in 10% of patients infected by the human immunodeficiency virus (HIV), as expression of severe and sometimes treatable diseases. However, the management of them is not well established. We analyzed, retrospectively, 26 brain biopsies (22 estereotaxic) in patients with HIV infection and BML to know their usefulness and safety. The inclusion criteria were: Failure of the anti-Toxoplasma empirical treatment, atypical scan appearance for toxoplasmosis, or severe neurological picture. Brain biopsy yielded a diagnosis in 19 patients (73.1%): Progressive multifocal leukoencephalopathy (n = 8; 30.8%), primary central nervous system lymphoma (n = 6; 23.1%), mycobacteriosis (n = 2; 7.7%), toxoplasmosis (n = 2; 7.7%), criptococcosis (n = 1), cryptosporidiosis (n = 1) and HIV-encephalitis (n = 1). In one case there was a multiple diagnosis: mycobacteriosis, toxoplasmosis, and lymphoma. Brain biopsy results decided a change in therapy in 65.4%, the resolution or improvement of the neurological process in 30.8%, and the determination of the prognosis in 30.8%. In 8 cases (30.7%) there were biopsy complications, with secondary mortality in one. Brain biopsy of BML in HIV-infected patients is a diagnostic method with a high overall diagnostic rentability and uncommon non reversible complications, offering the possibility to prescribe a specific and potentially curative treatment.

Thyrotropin-like immunoreactivity in human retina: immunoreactive co-localization in ganglion cells and perivascular fibers.

The present immunocytochemical study has demonstrated immunoreactive thyrotropin-like ganglion cell populations as well as perivascular fibers in the human retina by using specific antiserum. Thyrotropin is a pituitary glycopeptide involved in the synthesis and release of thyroid hormones. The existence and functions of peptides in vertebrate retinas are still not well known. Many authors have reported neuropeptide immunoreactivity in the human retina which have had their functions established in the neuroregulatory processes of vision. Moreover, some authors have reported the possibility that the fiber terminal of peptidergic neurons may also be a blood vessel. The appearance of immunoreactive-cells in human retina, e.g. existence of retinal ganglion cells with thyrotropin-like immunoreactivity, indicates the existence of specific mechanisms that would be mediated by these peptides which are located near immunoreactive ganglion cells. We hypothesize that there is an intrinsic mechanism for blood flow control, mediated by retinal ganglion cells which may regulate vessel diameter according to its luminous stimuli. No-one has demonstrated the presence or the functional existence of thyrotropin-like immunoreactive structures in the vertebrate retina, or on the side of the pituitary-thyroid axis. To the best of our knowledge this is the first time that thyrotropin has been immunocytochemically demonstrated in the human retina. Thus, we suggest that thyrotropin acts as a neuromodulator in the human retina, which is implicated in blood flow control.