RESUMO

A recent paper by Beretta-Blanco and Carrasco-Letelier (2021) claims that agricultural eutrophication is not one of the main causes for cyanobacterial blooms in rivers and artificial reservoirs. By combining rivers of markedly different hydrological characteristics e.g., presence/absence and number of dams, river discharge and geological setting, the study speculates about the role of nutrients for modulating phytoplankton chlorophyll-a. Here, we identified serious flaws, from erratic and inaccurate data manipulation. The study did not define how erroneous original dataset values were treated, how the variables below the detection/quantification limit were numerically introduced, lack of mandatory variables for river studies such as flow and rainfall, arbitrary removal of pH > 7.5 values (which were not outliers), and finally how extreme values of other environmental variables were included. In addition, we identified conceptual and procedural mistakes such as biased construction/evaluation of model prediction capability. The study trained the model using pooled data from a short restricted lotic section of the (large) Uruguay River and from both lotic and reservoir domains of the Negro River, but then tested predictability within the (small) Cuareim River. Besides these methodological considerations, the article shows misinterpretations of the statistical correlation of cause and effect neglecting basic limnological knowledge of the ecology of harmful algal blooms (HABs) and international research on land use effects on freshwater quality. The argument that pH is a predictor variable for HABs neglects overwhelming basic paradigms of carbon fluxes and change in pH because of primary productivity. As a result, the article introduces the notion that HABs formation are not related to agricultural land use and water residence time and generate a great risk for the management of surface waterbodies. This reply also emphasizes the need for good practices of open data management, especially for public databases in view of external reproducibility.

Assuntos

Negro ou Afro-Americano , Rios , Monitoramento Ambiental , Eutrofização , Proliferação Nociva de Algas , Humanos , Fósforo/análise , Reprodutibilidade dos Testes , Uruguai

RESUMO

Erythropoietin, a multitarget molecule exhibited neuroprotective properties, especially against cerebral ischemia. However, little effort has been made to determinate both the administration pathway and doses that diminishes neuronal damage. In this study, we investigate the effect on CA1 region of different intranasal doses of rHuEPO (500, 1000 and 2500 IU/kg) applied in distinct post-damage times (1, 6, and 24 h) against ischemic cellular damage. Furthermore, most effective dose and time were used to evaluate gen and protein expression changes in 3 key molecules (EPO, EPOR, and ßcR). We established that CA1-region present histopathological damage in this ischemia model and that rHuEPO protects cells against damage, particularly at 1000 IU dose. Molecular data shows that EPO and EPOR gene expression are upregulated in a short term after damage treatment with rHuEPO (1 h); oppositely, BcR is upregulated in ischemic and Isc + EPO. Protein expression data displays no changes on EPO expression in evaluated times after treatment, but a tendency to increase 24 h after damage; in the opposite way, EPOR is upregulated significantly 6 h after treatment and this effect last until 24 h. So, our data suggest that a single intranasal dose of rHuEPO (1 h post-injury) provides histological neurorestoration in CA1 hippocampal region, even if we did not observe a dose-dependent dose effect, the medium dose evaluated (1000 UI/kg of b.w.) was more effective and sufficient for induces molecular changes that provides a platform for neuroprotection.

Assuntos

Isquemia Encefálica/tratamento farmacológico , Região CA1 Hipocampal/efeitos dos fármacos , Eritropoetina/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Administração Intranasal , Animais , Região CA1 Hipocampal/metabolismo , Eritropoetina/administração & dosagem , Eritropoetina/farmacologia , Humanos , Masculino , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Wistar

RESUMO

Predation is considered to be an important factor structuring natural communities. However, it is often difficult to determine how it may influence long-term, broad-scale, diversity patterns, particularly in diverse tropical systems. Biological introductions can provide powerful insight to test the sustained consequences of predation in natural communities, if pre-introduction data are available. Half a century ago, Zaret and Paine demonstrated strong and immediate community-level effects following the introduction of a novel apex predator (peacock bass, Cichla monoculus) into Lake Gatun, Panama. To test for long-term changes associated with this predator introduction, we followed up on their classic study by replicating historical sampling methods and examining changes in the littoral fish community at two sites in Lake Gatun 45 years post-introduction. To broaden our inference, we complemented this temporal comparison with a spatial analysis, wherein we compared the fish communities from two lakes with and one lake without peacock bass. Comparisons with historical data revealed that the peacock bass remains the most abundant predator in Lake Gatun. Furthermore, the collapse of the littoral prey community observed immediately following the invasion has been sustained over the past 45 years. The mean abundance of native littoral fish is now 96% lower than it was prior to the introduction. Diversity (rarefied species richness) declined by 64% post-introduction, and some native species appear to have been locally extirpated. We observed a similar pattern across invaded and uninvaded lakes: the mean abundance of native fishes was 5-40 times lower in lakes with (Gatun, Alajuela) relative to the lake without peacock bass (Bayano). In particular, small-bodied native fishes (Characidae, Peociliidae), which are common prey of the peacock bass, were more than two orders of magnitude (307 times) less abundant in Gatun and one order of magnitude (28 times) less abundant in Alajuela than in Bayano. However, total native fish diversity did not differ significantly across lakes, suggesting that while many native species have declined in abundance, few have been completely extirpated. Introduced predators can have strong effects on community structure and functional diversity, even in highly diverse tropical communities, and these effects can persist over multiple decades.

Assuntos

Ecossistema , Peixes , Cadeia Alimentar , Comportamento Predatório , Animais , Lagos , Panamá

RESUMO

Adaptive radiation can be strongly influenced by interspecific competition for resources, which can lead to diverse outcomes ranging from competitive exclusion to character displacement. In each case, sympatric species are expected to evolve into distinct ecological niches, such as different food types, yet this expectation is not always met when such species are examined in nature. The most common hypotheses to account for the coexistence of species with substantial diet overlap rest on temporal variation in niches (often diets). Yet spatial variation in niche overlap might also be important, pointing to the need for spatiotemporal analyses of diet and diet overlap between closely related species persisting in sympatry. We here perform such an analysis by characterizing the diets of, and diet overlap among, four sympatric Darwin's ground finch species at three sites and over 5 years on a single Galápagos island (Santa Cruz). We find that the different species have broadly similar and overlapping diets - they are to some extent generalists and opportunists - yet we also find that each species retains some 'private' resources for which their morphologies are best suited. Importantly, use of these private resources increased considerably, and diet overlap decreased accordingly, when the availability of preferred shared foods, such as arthropods, was reduced during drought conditions. Spatial variation in food resources was also important. These results together suggest that the ground finches are 'imperfect generalists' that use overlapping resources under benign conditions (in space or time), but then retreat to resources for which they are best adapted during periods of food limitation. These conditions likely promote local and regional coexistence.

Assuntos

Adaptação Fisiológica , Dieta , Comportamento Alimentar , Tentilhões/fisiologia , Animais , Evolução Biológica , Comportamento Competitivo , Equador , Tentilhões/anatomia & histologia , Dinâmica Populacional , Simpatria

RESUMO

Anomalous pulmonary venous connection is a rare pathology, both partial and total forms, according to the number of pulmonary veins draining into the left atrium, respectively. Total forms are classified into four groups, depending upon the anomalous connections to the systemic veins: supra, intracardiac or below, and finally a mixed form, the less frequent. Prenatal, even postnatal diagnose is difficult, especially in partial isolated forms. The association with chromosomal abnormalities is low, however is highly associated with complex heart malformations, especially total forms, often in the context of heterotaxy syndromes. We present a case of infracardiac APVC, in the context of complex heart disease, associated with complete atrioventricular canal and conotruncal anomaly, that came to surgery at 48 hours of life with poor outcome. We described the ultrasound and magnetic resonance angiography of this anomaly and its perinatal prognosis and management.

Assuntos

Angiografia por Ressonância Magnética/métodos , Veias Pulmonares/anormalidades , Ultrassonografia Pré-Natal/métodos , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Prognóstico , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/cirurgia

Assuntos

Humanos , Masculino , Feminino , Imagem de Perfusão do Miocárdio , Eletrocardiografia , Isquemia Miocárdica/diagnóstico

RESUMO

Helicobacter pylori (Helicobacter p.) es una bacteria que se aloja a nivel de la mucosa gástrica la cual presenta una prevalencia variable y está asociada al desarrollo de úlceras pépticas, linfomas y cáncer gástrico. Aproximadamente el 40% de los individuos en países desarrollados están afectados y hasta un 85%, en los países subdesarrollados, por ello, se asocia con un bajo nivel socioeconómico. Recientemente se ha propuesto el uso de una terapia secuencial con el objetivo de erradicar la infección por Helicobacter p. El objetivo de este estudio consiste en comparar la efectividad de ambos tratamientos en la consulta del Servicio de Gastroenterología del Hospital “Carlos J. Bello” en el período de febrero 2008 a octubre 2009, en un total de 83 pacientes, 77,1% de sexo femenino, y 22,9% de sexo masculino. El grupo que recibió tratamiento convencional representó el 57,83%, del total de pacientes estudiados, y el grupo que recibió tratamiento secuencial, representó el 42,17%. En cuanto a la efectividad, el tratamiento convencional fue efectivo en un 46,99%, y el secuencial en un 32,53%, dentro de su propio grupo de pacientes. La prueba X2 no representó diferencia significativa entre la efectividad de ambos tratamientos.

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Helicobacter pylori (Helicobacter p. ) Its a bacteria that lives in the gastric mucosa and its prevalence is variable and it is associated to the development of peptic ulcer, lymphoma, and gastric cancer. Approximately 40% of individuals in developed countries are affected and 85% in undeveloped countries in which are related to low socioeconomics level. Recently its been proposed the use of a sequential therapy to eradicate the infection by Helicobacter p. The objective of this study consist in to compare the effectiveness between both treatments (Sequential and conventional) in the consult from the Gastroenterology Service of the Carlos J. Bello Hospital in a period of time between February 2008 to October 2009 in a total of 83 patients, 77,1% feminine, 22,9% masculine. The group that received conventional treatment represented 57,83% and sequential 42,17%. In regard to the effectiveness the conventional group presented 46, 99% and sequential group 32, 53%. The X2 test it didn’t present significative difference of effectiveness between both treatments.

Assuntos

Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/terapia , Ligadura/métodos , Linfoma/prevenção & controle , Neoplasias Gástricas/prevenção & controle , Antibioticoprofilaxia/métodos , Propranolol/uso terapêutico , Úlcera Péptica/patologia , Varizes Esofágicas e Gástricas/patologia , Gastroenterologia

RESUMO

The evolution of treatment of chronic hepatitis C virus infection has led to improved therapeutic efficacy. However, a major problem is the presence of side effects that require modification or withdrawal of drug therapy in 15-20% of cases. This could potentially influence the lack of sustained viral response in 50% of the cases. Side effects are common, even with pegylated interferon. This study aimed to assess the incidence and severity of infections based on the development of neutropenia associated with combined therapy with pegylated interferon-alpha2a plus ribavirin in 209 patients with chronic hepatitis C infection. All patients were administered pegylated interferon-alpha2a (180 microg/week) plus ribavirin (800 mg/day for 24 weeks in cases of nongenotype 1, or 1000-1200 mg/day for 48 weeks for genotype 1, according to whether patients weighed more or less than 75 kg). Patients with preexisting neutropenia of any cause or cirrhosis were excluded. Neutropenia was defined as a neutrophil count (NC) of <1500 cells/microl. Neutropenia was classified into three levels during treatment: 750

Assuntos

Antivirais/efeitos adversos , Hepatite C Crônica/complicações , Interferon-alfa/efeitos adversos , Neutropenia/induzido quimicamente , Ribavirina/efeitos adversos , Adulto , Idoso , Antivirais/uso terapêutico , Quimioterapia Combinada , Feminino , Hepatite C Crônica/tratamento farmacológico , Humanos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Contagem de Leucócitos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Neutropenia/patologia , Polietilenoglicóis , Proteínas Recombinantes , Ribavirina/uso terapêutico

RESUMO

The aim of the study was to determine whether collagen-polyvinylpyrrolidone (collagen-PVP) modifies some proinflammatory responses in synovium cultures from rheumatoid arthritis (RA) patients. Synovium from 10 RA patients were cultured with or without 1% collagen-PVP. Tissues on the 3rd, 5th and 7th culture day were sectioned and stained by the Herovici technique. Total collagen and type I/III collagen ratios were evaluated by the Woessner micromethod and by interrupted gel electrophoresis, respectively. Collagenolytic activity was assessed by degradation of [3H]-collagen in supernatants. TIMP-1, IL-1beta and TNF-alpha were determined in supernatants by ELISA, and the results were normalized by DNA concentration. IL-1beta, TNF-alpha, IL-6, IL-8, MMP-1, TIMP-1, Cox-1, VCAM-1, ICAM-1 and Fas/APO95 expression was evaluated by immunohistochemistry. Apoptosis was detected by TUNEL technique. The histological analysis and electrophoresis revealed a 1.7-fold increase of type III collagen in a time-dependent fashion in collagen-PVP-treated cultures. Proinflammatory cytokines (IL-1beta: 58 +/- 9 versus 22 +/- 10; TNF-alpha: 41 +/- 6 versus 11 +/- 3; IL-8: 59 +/- 12 versus 29 +/- 9; treated versus untreated), adhesion molecule (ICAM-1: 57 +/- 11 versus 29 +/- 15; VCAM-1: 49 +/- 7 versus 21 +/- 13; treated versus untreated) as well as Cox-1 (59 +/- 10 versus 20 +/- 3) expression was down-regulated in RA synovium treated. Meanwhile, TIMP-1 (36 +/- 7 versus 57 +/- 11) and Fas expression (20 +/- 10 versus 55 +/- 13) and apoptosis (14 +/- 3 versus 55 +/- 5) were up-regulated in treated cultures compared with controls. In supernatants, the collagenolytic activity, as well as IL-1beta and TNF-alpha, levels were all down-regulated in treated cultures (two, three, fourfold, respectively). The addition of collagen-PVP to synovium-induced down-modulation of some inflammatory parameters and an increase in apoptosis of synovial cells. Perhaps this mechanism could contribute to inhibit outgrowth of pannus formation and to down-regulate inflammation of joints in patients with RA.

Assuntos

Apoptose/efeitos dos fármacos , Artrite Reumatoide/metabolismo , Doenças Autoimunes/metabolismo , Colágeno/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Povidona/farmacologia , Membrana Sinovial/efeitos dos fármacos , Adulto , Idoso , Apoptose/fisiologia , Artrite Reumatoide/patologia , Doenças Autoimunes/patologia , Moléculas de Adesão Celular/biossíntese , Moléculas de Adesão Celular/genética , Ciclo-Oxigenase 1 , Citocinas/biossíntese , Citocinas/genética , Indução Enzimática/efeitos dos fármacos , Proteína Ligante Fas , Feminino , Humanos , Interleucinas/biossíntese , Interleucinas/genética , Isoenzimas/biossíntese , Isoenzimas/genética , Masculino , Metaloproteinase 1 da Matriz/biossíntese , Metaloproteinase 1 da Matriz/genética , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Proteínas de Membrana , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Prostaglandina-Endoperóxido Sintases/biossíntese , Prostaglandina-Endoperóxido Sintases/genética , Membrana Sinovial/metabolismo , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Inibidor Tecidual de Metaloproteinase-1/genética , Receptor fas/biossíntese , Receptor fas/genética

Assuntos

Toxinas Bacterianas/análise , Microcystis/isolamento & purificação , Peptídeos Cíclicos/análise , Microbiologia da Água , Água Doce , Microcistinas , Microcystis/patogenicidade

RESUMO

OBJECTIVE: The purpose of the present study was to determine the associations of cold pressor test (CPT) cardiovascular reactivity with gestational age at birth and neonatal size in normotensive pregnant women. METHODS: Seventy (70) healthy pregnant women were enrolled. The CPT consisted of introducing the patients' hands in cold water (4 degrees C) for 3 min. An automatic oscillometric device was used to record blood pressure (BP) every minute for the following 5 min. Perinatal results were correlated with CPT findings. RESULTS: Vascular reactivity assessed by CPT was higher in pregnant hypertensive women and in women with a hypertensive family history. Mean BP increases caused by CPT showed a significant negative correlation for gestational age (r = -0.58, p < 0.001) and cephalic perimeter (r = -0.57, p = 0.03). Diastolic BP increases caused by CPT were negatively correlated with newborn weight (r = -0.78, p < 0.001). Predictable newborn weight, gestational age, and cephalic perimeter were 4046 (47 x diastolic BP increase), 40.2 (0.07 x mean BP increase), and 35.8 (0.09 x mean BP increase), respectively. CONCLUSIONS: Results show that every mm Hg diastolic BP increase in response to CPT was correlated with a 47-g decrease in the newborn normal weight. Furthermore, every mean mm Hg BP increase in response to CPT was associated with a 0.07-week decrease in the newborn normal gestational age and a 0.09-cm decrease in the normal cephalic perimeter at birth.

Assuntos

Peso ao Nascer , Temperatura Baixa , Sistema Vasomotor/fisiologia , Adulto , Antropometria , Pressão Sanguínea , Estatura , Feminino , Idade Gestacional , Cabeça/fisiologia , Humanos , Recém-Nascido , Gravidez

RESUMO

BACKGROUND: Great interest has sparked recently the role that plays the changes that the growth hormone undergoes in the menopausal woman, specially its involvement in the central nervous, cardiovascular, genitourinary, digestive and osteomuscular systems. OBJECTIVE: To evaluate the influence of transdermal administration of 17-beta estradiol on growth hormone secretion in menopausal women before and after treatment under the stimulus of growth-hormonereleasing hormone (GH-RH). MATERIAL AND METHODS: We studied 5 patients with a mean age of 51 +/- 4.1 yr. with clinical and biochemical evidence of menopause. Evolution time 5.4 +/- 4.61 (range: 1-13 yr.). We monitored the pulsatility of GH during the first 120 minutes and 3 hours after the administration of the GHRH-1-29-NH2, i.v. bolus (50 micrograms). There were obtained every 15 minutes for the determination of GH levels before and after the stimulus. Immediately thereafter hormone replacement therapy was initiated with transdermal beta-estradiol with 50 micrograms patches twice a week. Clinical evaluations and hormone dynamics with OHRH-1-29 were performed at baseline and at 1,3 and 6 months from the start of therapy as described previously. RESULTS: GH pulsatility before estrogen replacement therapy (ERT) in these 5 patients was: X: 0.48 +/- 0.22, 0.38 +/- 0.17, 0.45 +/- 0.25 and 0.29 (at baseline, 1, 3 and 6 months respectively) and 2.74 +/- o 1.21; 3.48 +/- 1.32 (p > 0.05) 4.91 +/- 1.57 (p < 0.05) and 6.04 +/- 1.69 (p < 0.05) (p in relation to baseline) post stimulus with GH-RH-1-29 at baseline 1, 3 and 6 months respectively after transdermal estrogen therapy. Gonadotrophins basal serum levels fall from X: 54.68 +/- 27 to 33.20 +/- 11.23 and 40.48 +/- 12 to 28.30 +/- 6.70 (FSH and LH respectively). Estradiol serum level were from 1.82 +/- 4.06 to 25.95 +/- 5.96 before and after treatment, respectively. COMMENTS AND CONCLUSIONS: These results demonstrate that transdermal estrogen therapy does not modify the pulsatility of growth hormone but it does increase the magnitude of response to the stimulus with GH-RH-1-29 proportional to the time of treatment. We consider that this tendency to increase the production of growth hormone could be explained by an endogenous deficit of growth hormone releasing hormone due to a number of factors including the lack of adequate estrogen serum levels in menopausal women. More investigations will be needed to support this hypothesis and to bring forth a new understanding of menopause and its treatment.

Assuntos

Climatério , Estradiol/administração & dosagem , Hormônio Liberador de Hormônio do Crescimento/efeitos dos fármacos , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Administração Cutânea , Adulto , Feminino , Humanos , Pessoa de Meia-Idade

RESUMO

A 24-year-old woman with CML underwent allogeneic BMT in August 1995 from a one-antigen HLA mismatched brother. Conditioning included BuCy2 and CsA and MTX were used to prevent GVHD. In July 1997 she developed right leg pain, lytic bone lesions of distal femur and a solid mass of soft tissue. Histological diagnosis of malignant fibrous histiocytoma was made. Despite treatment with surgery and chemotherapy (doxorubicin and ifosfamide), the patient died 1 year later with local recurrence of the tumor and liver, lung and brain metastases. The CML was in CR.

Assuntos

Transplante de Medula Óssea/efeitos adversos , Histiocitoma Fibroso Benigno/etiologia , Leucemia Mieloide de Fase Crônica/terapia , Segunda Neoplasia Primária/etiologia , Adulto , Feminino , Neoplasias Femorais/diagnóstico , Neoplasias Femorais/etiologia , Histiocitoma Fibroso Benigno/diagnóstico , Humanos , Masculino , Segunda Neoplasia Primária/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/etiologia , Transplante Homólogo

Assuntos

Artrite Reumatoide/metabolismo , Colágeno/metabolismo , Colágeno/farmacologia , Povidona/farmacologia , Membrana Sinovial/metabolismo , Adulto , Animais , Células Cultivadas , Regulação da Expressão Gênica , Humanos , Molécula 1 de Adesão Intercelular/genética , Cinética , Ratos , Membrana Sinovial/efeitos dos fármacos , Molécula 1 de Adesão de Célula Vascular/genética

RESUMO

The authors present the clinical findings, diagnosis and treatment of vascular rings and their review of 12 cases treated between 1973 and 1998 at the Hospital del Niño, Panama city, Panama

Assuntos

Humanos , Masculino , Feminino , Lactente , Aorta Torácica/anormalidades , Aorta Torácica/cirurgia , Artéria Subclávia/anormalidades , Artéria Subclávia/cirurgia , Canal Arterial/anormalidades , Canal Arterial/cirurgia , Panamá

RESUMO

BACKGROUND: The mechanism of Mycobacterium tuberculosis penetration into tissues is poorly understood but it is reasonable to assume that there is a contribution from proteases capable of disrupting the extracellular matrix of the pulmonary epithelium and the blood vessels. A study was undertaken to identify and characterise collagen degrading activity of M tuberculosis. METHODS: Culture filtrate protein extract (CFPE) was obtained from reference mycobacterial strains and mycobacteria isolated from patients with tuberculosis. The collagen degrading activity of CFPE was determined according to the method of Johnson-Wint using 3H-type I collagen. The enzyme was identified by the Birkedal-Hansen and Taylor method and its molecular mass determined by SDS-PAGE and Sephacryl S-300 gel filtration chromatography using an electroelution purified enzyme. RESULTS: CFPE from Mycobacterium tuberculosis strain H37Rv showed collagenolytic activity that was four times higher than that of the avirulent strain H37Ra. The 75 kDa enzyme responsible was divalent cation dependent. Other mycobacterial species and those isolated from patients with tuberculosis also had collagen degrading activity. CONCLUSIONS: Mycobacterium species possess a metalloprotease with collagen degrading activity. The highest enzymatic activity was found in the virulent reference strain H37Rv.

Assuntos

Colágeno/metabolismo , Metaloendopeptidases/isolamento & purificação , Mycobacterium tuberculosis/enzimologia , Técnicas Bacteriológicas , Humanos , Metaloendopeptidases/metabolismo , Peso Molecular , Tuberculose/microbiologia

RESUMO

The authors present the clinical findings, diagnosis and treatment of vascular rings and their review of 12 cases treated between 1973 and 1998 at the Hospital del Niño, Panama city, Panama.

Assuntos

Aorta Torácica/anormalidades , Aorta Torácica/cirurgia , Canal Arterial/anormalidades , Canal Arterial/cirurgia , Artéria Subclávia/anormalidades , Artéria Subclávia/cirurgia , Feminino , Hospitais Pediátricos , Humanos , Lactente , Masculino , Panamá

RESUMO

We evaluated the in situ expression of adhesion molecules (E-selectin and vascular cell-adhesion molecule) and proinflammatory/fibrogenic cytokines (IL-1beta, TNF-alpha, TGF-beta1, and PDGF) in sections of normal skin, hypertrophic scar, and hypertrophic scar previously treated with an irradiated mixture of collagen-polyvinylpyrrolidone and completely resolved. Expression of these proteins was detected by indirect immunoperoxidase staining. The hypertrophic scar group displayed an increased amount of IL-1beta, TNF-alpha, TGF-beta1, and PDGF compared with the normal skin and treated scar groups. Values were statistically significant when cytokines in hypertrophic scar and hypertrophic treated sections were compared. Surprisingly, no differences were detected between normal skin and treated scars. On the other hand, differences in levels of E-selectin and vascular cell-adhesion molecule were not statistically significant between the groups, except for vascular cell-adhesion molecule, which decreased in treated scars. Also, supernatants from fibroblast cultures derived from treated hypertrophic scar, showed a reduction in TGF-beta1 and PDGF expression, although apparently collagen synthesis was not affected. Based on previous data from clinical studies in human dermal fibrosis remodeling, and the results presented here, we suggest that collagen-polyvinylpyrrolidone modulates extracellular matrix turnover, mainly of collagen, because expression levels of IL-1beta, TNF-alpha, TGF-beta1, and PDGF were diminished. We infer that collagen-polyvinylpyrrolidone participation could also modify the inflammatory process observed in hypertrophic scarring, by diminishing the expression of adhesion molecules, as a consequence of lower levels of proinflammatory cytokines, mainly IL-1beta and TNF-alpha.

Assuntos

Cicatriz Hipertrófica/metabolismo , Colágeno/fisiologia , Citocinas/biossíntese , Povidona/farmacologia , Adolescente , Adulto , Moléculas de Adesão Celular/biossíntese , Criança , Colágeno/metabolismo , Meios de Cultura/química , Regulação para Baixo , Selectina E/biossíntese , Feminino , Fibroblastos/citologia , Humanos , Interleucina-1/biossíntese , Masculino , Fator de Crescimento Derivado de Plaquetas/biossíntese , Pele/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Molécula 1 de Adesão de Célula Vascular/biossíntese

RESUMO

OBJECTIVE: To investigate the spontaneous cytokine gene expression in fibroblasts from patients with diffuse cutaneous systemic sclerosis. Their pattern of expression was correlated with the production of collagen. METHODS: Fibroblasts were obtained from skin biopsies of nine patients diagnosed with systemic sclerosis (mean 16 +/- 8.7 years of disease duration) and ten control individuals. The cytokine gene expression was detected by coupled reverse transcriptase polymerase chain reaction for interleukins 1 beta, 6, 8, tumour necrosis factor-alpha, and transforming growth factor beta. In addition, collagen synthesis was measured by [14C]-proline uptake in fibroblast cultures. RESULTS: All fibroblast samples from patients expressed the interleukin-6 gene (p = 0.04 compared with controls). Eight of the nine patients expressed interleukin-8 (p = 0.02 compared with controls). Four of them expressed also transforming growth factor beta and two more weakly expressed the tumour necrosis factor-alpha gene. Only one patient showed transcription for the interleukin-1 beta gene. In accordance with such immune activation, collagen synthesis was higher in fibroblasts from patients with systemic sclerosis (p = 0.028) as compared with normal controls. Indeed, a positive correlation was found between the expression of IL-6 gene and collagen production (rs = 1). CONCLUSION: The constitutive expression of IL-6 and IL-8 genes by fibroblasts may play an important role in the perpetuation of local immune dysregulation, thus leading to a permanent fibroblast activation in patients with systemic sclerosis.

Assuntos

Colágeno/biossíntese , Citocinas/genética , Expressão Gênica , Escleroderma Sistêmico/genética , Adolescente , Adulto , Estudos de Casos e Controles , Células Cultivadas , DNA/análise , Feminino , Fibroblastos , Humanos , Masculino , Pessoa de Meia-Idade , Prolina/metabolismo , Escleroderma Sistêmico/imunologia

RESUMO

Fecal samples and small intestinal content obtained by Enterotest were submitted between December 1994 and January 1996, by HIV (+) patients with gastrointestinal symptoms.Unconcentrated and concentrated fecal samples (by Sheater, Ritchie and Spontaneous Sedimentation) and intestinal content obtained by Enterotest, all stained by modificated Ziehl-Nielsen method, were compared (multiatributive comparison) based on the following parameters: yield, each test cost, morphology and the number of parasites per slide, in order to diagnose Cryptosporidium spp. e Isospora belli.Intestinal content obtained by Enterotest on the diagnosis of Cryptosporidium spp. e Isospora belli was not better than the fecal samples but it is more expensive. However, it reached a good diagnostic yield with adequate morphology, and a number of parasites per slide. Furthermore, it can be used as a second line diagnostic method (first line = fecal samples) and as an alternative in places where the use of endoscopy is not available.