RESUMO
Analysis of skeletal, cephalometric, and volumetric changes and occlusion during long-term follow-up was performed for two patients who underwent bimaxillary facial transplantation (FT). The study material consisted of the follow-up data of two bimaxillary composite FT performed in Helsinki University Hospital, one in 2016 and the other in 2018. Serial three-dimensional computed tomography scans obtained during follow-up (6 years for patient 1, 4 years for patient 2) were analyzed. The position of the maxilla remained stable in both patients. At 4 and 6 years, the changes in the anterior maxilla were ≤1 mm, while the anterior mandible had moved 2.6-4 mm anteriorly and the mandibular midline 0.4-3.7 mm to the left side. Patient 1 underwent re-osteosynthesis 4 months after transplantation due to mandibular non-union. Patient 2 had a sagittal mandibular osteotomy at 15 months after FT due to lateral crossbite and tension created by temporomandibular joint rotation. Thereafter both patients had a stable occlusion. A continuous bone volume reduction in the mandible was noticed in both patients (6% and 9% reduction of the transplanted volume). The volume of the transplanted maxilla decreased during the early postoperative period but increased back to the original transplanted volume during the follow-up.
RESUMO
PURPOSE: The aim of this study was to evaluate the long-term health-related quality of life (HRQoL) of head and neck cancer patients with microvascular surgery. Surgical treatment causes great changes in patient HRQoL. Studies focusing on long-term HRQoL after microvascular reconstruction for head and neck cancer patients are scarce. METHODS: We conducted a prospective study of 93 patients with head and neck cancer and microvascular reconstruction in Helsinki University Hospital Finland. HRQoL was measured using the 15D instrument at baseline and after a mean 4.9-years follow up. Results were compared with those of an age-standardized general population. RESULTS: Of the 93 patients, 61 (66%) were alive after follow-up; of these, 42 (69%) answered the follow-up questionnaire. The median time between surgery and HRQoL assessment was 4.9 years (range 3.7-7.8 years). The mean 15D score of all patients (n = 42) at the 4.9-years follow up was statistically significantly (p = 0.010) and clinically importantly lower than at baseline. The dimensions of "speech" and "usual activities" were significantly impaired at the end of follow up. There was a significant difference at the 4.9-years follow-up in the mean 15D score between patients and the general population (p = 0.014). After follow up, patients were significantly (p < 0.05) worse off on the dimensions of "speech," "eating," and "usual activities." CONCLUSIONS: Long-term HRQoL was significantly reduced in the whole patient cohort. Speech and usual activities were the most affected dimensions in head and neck cancer patients with microvascular reconstruction at the end of the 4.9-years follow up.
Assuntos
Neoplasias de Cabeça e Pescoço , Qualidade de Vida , Finlândia , Seguimentos , Humanos , Estudos Prospectivos , Inquéritos e QuestionáriosRESUMO
BACKGROUND AND AIMS:: This study compared the three most used composite flaps in maxillofacial reconstructions in our institute. PATIENTS AND METHODS:: Between 2000 and 2012, a total of 163 patients with mandibular, maxillary, and orbital defects received either scapular, fibular, or iliac crest osseal reconstructions in Helsinki University Hospital, Departments of Plastic Surgery and Maxillofacial Surgery. Data regarding the patient demographics, complications, and outcomes were analyzed. RESULTS:: There were 92 deep circumflex iliac artery flaps (56%), followed by 42 scapular (26%) and 29 fibular flaps (18%). The rate of flap loss was the highest in the deep circumflex iliac artery group (p = 0.001). Reconstructions using fibula were fastest (p = 0.001) and had lowest perioperative blood loss (p = 0.013). There were no significant differences in the number of early or late complications between the flaps, but donor site complications were more severe in deep circumflex iliac artery. Osteotomies as well as dental implants were safely performed in all flaps with equal results. CONCLUSION:: All three flaps of this study can be performed with awareness of the deep circumflex iliac artery flap being the least reliable alternative. The knowledge of the advantages and disadvantages of several osseal-free flap alternatives is beneficial in selecting the best suitable method for each individual patient requiring maxillofacial osseal reconstruction.
Assuntos
Fíbula/transplante , Retalhos de Tecido Biológico/transplante , Ílio/transplante , Traumatismos Maxilofaciais/cirurgia , Escápula/transplante , Alotransplante de Tecidos Compostos Vascularizados/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transplante Ósseo/métodos , Feminino , Retalhos de Tecido Biológico/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Masculino , Mandíbula/cirurgia , Traumatismos Mandibulares/cirurgia , Maxila/lesões , Maxila/cirurgia , Traumatismos Maxilofaciais/etiologia , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Bucais/métodos , Órbita/lesões , Órbita/cirurgia , Osteotomia , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Ferida Cirúrgica/etiologia , Ferida Cirúrgica/cirurgia , Adulto JovemRESUMO
OBJECTIVES: Glucocorticoids are widely used in association with major surgery of the head and neck to improve postoperative rehabilitation, shorten intensive care unit and hospital stay, and reduce neck swelling. This study aimed to clarify whether peri- and postoperative use of dexamethasone in reconstructive head and neck cancer surgery is associated with any advantages or disadvantages. MATERIALS AND METHODS: This prospective double-blind randomized controlled trial comprised 93 patients. A total dose of 60mg of dexamethasone was administered to 51 patients over three days peri- and postoperatively. The remaining 42 patients served as controls. The main primary outcome variables were neck swelling, length of intensive care unit and hospital stay, duration of intubation or tracheostomy, and delay to start of possible radiotherapy. Complications were also recorded. RESULTS: No statistical differences emerged between the two groups in any of the main primary outcome variables. However, there were more major complications, especially infections, needing secondary surgery within three weeks of the operation in patients receiving dexamethasone than in control patients (27% vs. 7%, p=0.012). CONCLUSIONS: The use of dexamethasone in oral cancer patients with microvascular reconstruction did not provide a benefit. More major complications, especially infections, occurred in patients receiving dexamethasone. Our data thus do not support the use of peri- and postoperative dexamethasone in oropharyngeal cancer patients undergoing microvascular reconstruction.
Assuntos
Dexametasona/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Microcirculação , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Procedimentos de Cirurgia PlásticaRESUMO
BACKGROUND AND AIMS: Prosthetic mask restoration of the donor face is essential in current facial transplant protocols. The aim was to develop a new three-dimensional (3D) printing (additive manufacturing; AM) process for the production of a donor face mask that fulfilled the requirements for facial restoration after facial harvest. MATERIALS AND METHODS: A digital image of a single test person's face was obtained in a standardized setting and subjected to three different image processing techniques. These data were used for the 3D modeling and printing of a donor face mask. The process was also tested in a cadaver setting and ultimately used clinically in a donor patient after facial allograft harvest. RESULTS: and Conclusions: All the three developed and tested techniques enabled the 3D printing of a custom-made face mask in a timely manner that is almost an exact replica of the donor patient's face. This technique was successfully used in a facial allotransplantation donor patient.
Assuntos
Transplante de Face/métodos , Procedimentos de Cirurgia Plástica , Coleta de Tecidos e Órgãos/métodos , Alotransplante de Tecidos Compostos Vascularizados/métodos , Cadáver , Desenho Assistido por Computador , Finlândia , Humanos , Impressão Tridimensional , Procedimentos de Cirurgia Plástica/métodos , Reprodutibilidade dos Testes , Doadores de TecidosRESUMO
Apoptosis is a normal physiological process which eliminates cells that do not receive adequate extracellular signals. One of the pathways signalling apoptosis is controlled by the small GTPases of the Rho family, also involved in cell proliferation, differentiation and motility. Another major apoptosis signalling pathway involves the p53 tumour suppressor which is activated by a variety of stress and mediates growth arrest or apoptosis in normal cells. We show here that upon detachment from the extracellular matrix, fibroblasts undergo rapid apoptosis that can be rescued by constitutive activation of Rac1 and Cdc42Hs GTPases. Conversely, inhibition of Rac1 and Cdc42Hs efficiently triggers apoptosis in adherent cells. Interestingly, apoptosis is not observed in p53-/- cells either cultured in suspension or inhibited for Rac1 and Cdc42Hs activity. Moreover, Rac1 and Cdc42Hs extinction in normal cells activates endogenous p53. Using specific inhibitors of MAPK pathways, we demonstrate that, in our experimental system, p38 signals survival, while ERK activity is required for apoptosis. Our data constitute the first demonstration that Rac1 and Cdc42Hs control pathways that require simultaneous signalling through MAPK ERK and p53 to induce apoptosis.
Assuntos
Apoptose , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Células 3T3 , Animais , Adesão Celular , Sobrevivência Celular , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases Ativadas por Mitógeno/metabolismoRESUMO
The tumour suppressor p53 plays a complex role in the regulation of apoptosis. High levels of wild type p53 potentiate the apoptotic response, while physiological range, low levels of the protein have an anti-apoptotic activity in serum starved immortalized fibroblasts. Here we report that primary fibroblast-like cells that show normal growth control are also efficiently protected from apoptosis by the endogenous p53 activity. The capacity to inhibit apoptosis is not restricted to the wild type protein: the R-->H175 p53 mutant fully retains the anti-apoptotic activity of the wild type p53, providing a possible explanation for its high oncogenicity. Using a series of point and deletion mutants of p53 under the control of tetracycline-regulated promoter we show that certain mutants, like the wild type, protect cells at low levels but lead to apoptosis when overexpressed. This latter effect is lost upon deletion of a proline-rich domain in the NH2 part of the protein. The anti-apoptotic activity can be mapped to the extreme carboxy-terminal part of the protein and is therefore independent of other well characterized p53 activities. Our results add a new level of complexity to the network of interactions mediated by p53 in normal physiology and pathology.
Assuntos
Apoptose , Transformação Celular Neoplásica/genética , Genes p53 , Mutação , Proteína Supressora de Tumor p53/genética , Animais , Meios de Cultura Livres de Soro , Análise Mutacional de DNA , Modelos Biológicos , Fragmentos de Peptídeos/genética , RatosRESUMO
Farmed mussels were artificially contaminated with a pure culture of an Alexandrium tamarense toxic strain (MOG 835), to assess the effect of initial toxicity on paralytic toxin change during the depuration process. As previously observed in mussel, gonyautoxin GTX2 is eliminated more slowly than other gonyautoxins. A toxic level (1300 micrograms PSP per 100 g meat) is required to produce a drastic change in the depuration course, i.e. a 'fast' depuration rate followed by a 'slow' one. Below this threshold, decontamination becomes slower as the proportion of GTX2 increases over the time course. Although GTX2 is slowly eliminated during the depuration process, it is also formed in increasing quantities during the contamination phase. It remains to be determined whether changes in GTX2/GTX3 ratios are due to chemical or biological transformation.
Assuntos
Bivalves/fisiologia , Saxitoxina/análogos & derivados , Animais , Biotransformação , Carne/análise , Saxitoxina/análise , Saxitoxina/farmacocinética , Saxitoxina/toxicidadeRESUMO
As a result of the proliferation of toxic marine dinoflagellates along European coasts and the recent discovery of paralytic poisons in French shellfish, experimental studies were conducted on four species of shellfish from the Brittany coasts. Contamination rates of a culture of toxic Protogonyaulax tamarensis, were determined for Mytilus edulis, Crassostrea gigas, Pecten maximus and Ruditapes philippinarum. Mussels and scallops were very rapidly contaminated showing high toxin accumulation rates, whereas rates for oysters and clams were low. During the decontamination phase, two stages were observed in mussels and scallops: a fast decrease in toxin, of the same order of magnitude as the accumulation, followed by a slow decrease, with the toxic rate remaining above the quarantine level of 80 micrograms/100 g. Toxin analysis, both in the culture and in the shellfish, was performed using high performance liquid chromatography. GTX3 and GTX8/epiGTX8 were the dominant toxins in the early stage of the decontamination phases, whereas GTX2 was the predominant compound during the slow phase of decontamination.
Assuntos
Dinoflagellida/isolamento & purificação , Contaminação de Alimentos/análise , Frutos do Mar/análise , Animais , Dinoflagellida/patogenicidade , França , Masculino , Camundongos , Saxitoxina/análogos & derivados , Saxitoxina/análiseRESUMO
To determine whether toxic metabolites produced by fungi could cause shellfish toxicities, mussels were contaminated in laboratory conditions by sterile filtrates of a liquid culture of a strain of the fungus Trichoderma koningii previously isolated from a shellfish, the cockle (Cerastoderma edule). Mussels were kept in aerated natural seawater and fed with a culture of the microalga Isochrysis galbana, to which a filtrate of liquid fungal culture was added. Mussels were exposed to contamination for 7 days at 16 or 20 degrees C and extractions were then performed and their activity tested on blowfly larvae. The same toxicity was found in the fungal filtrate and the shellfish, indicating bioaccumulation. The digestive gland was the most toxic part of the mussel, confirming contamination by filtration. Treated mussels produced a mucus which appeared to be a means of eliminating toxic metabolites.
Assuntos
Bivalves/metabolismo , Contaminação de Alimentos/análise , Toxinas Marinhas/metabolismo , Micotoxinas/metabolismo , Frutos do Mar/análise , Trichoderma/metabolismo , Animais , Cnidários , Eucariotos/metabolismo , Larva , Muco/metabolismo , TemperaturaRESUMO
Clara-cell secretory protein (CCSP), produced primarily by Clara cells in the conducting airways, is the most abundant soluble protein in pulmonary lavage fluid. CCSP is thought to be an immunosuppressive or anti-inflammatory protein with protective functions in the respiratory tract against exaggerated inflammatory reactions. CCSP was measured in 98 tracheoalveolar fluid (TAF) samples from 24 preterm infants (gestational age, 27.9 +/- 2.3 weeks, birth weight 1,020 +/- 305 g) with respiratory distress syndrome during the first 2 postnatal weeks. The ratio of urea-N in serum and in TAF was used to correct for dilution of TAF samples. Concentration of CCSP in TAF when corrected for dilution increased from 3.6 +/- 11 microg/mL on day 1 to 29.6 +/- 6.9 microg/mL on day 14. CCSP correlated with gestational age. A negative correlation was found between CCSP and inspiratory oxygen concentration, and a positive correlation between CCSP and both arterial pH and base excess during the first 2 postnatal weeks. Infants with clinical and laboratory signs of infection had higher CCSP than noninfected infants, and a negative correlation was found between CCSP and leukocyte count during the first 2 postnatal weeks (all P < 0.05). We suggest that pulmonary CCSP correlates with both gestational and postnatal age, and increases in response to infection in infants with respiratory distress during the early postnatal period.
Assuntos
Líquido da Lavagem Broncoalveolar/química , Inibidores Enzimáticos/análise , Recém-Nascido Prematuro/fisiologia , Proteínas/análise , Traqueia/química , Uteroglobina , Fatores Etários , Idade Gestacional , Humanos , Recém-Nascido , Doenças do Prematuro/patologia , Pulmão/crescimento & desenvolvimento , Mucosa Respiratória/citologia , Infecções Respiratórias/patologiaRESUMO
BACKGROUND: Severe central nervous system diseases, such as encephalitis, have been reported in association with Mycoplasma pneumoniae infections. CASE REPORT: After an ENT infection, a 9-year-old boy with Down's syndrome developed encephalitis revealed by an acute alteration in consciousness. Head computed tomography showed, after 2 weeks, an infiltration in the basal ganglia region. The diagnosis of Mycoplasma pneumoniae encephalitis was made; recovery was complete in a few weeks. CONCLUSION: Mycoplasma pneumoniae infection should be considered in all cases of acute encephalopathy; yet the pathogenesis of the disorder is unknown and the treatment uncertain.
Assuntos
Meningoencefalite/diagnóstico , Meningoencefalite/microbiologia , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/microbiologia , Mycoplasma pneumoniae , Doença Aguda , Criança , Coma/microbiologia , Diagnóstico Diferencial , Síndrome de Down/complicações , Humanos , Masculino , Prognóstico , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Hepatocyte growth factor (HGF), an epithelial cell mitogen, has been shown to participate in normal lung development and in regeneration after lung injury. In human preterm infants, lower pulmonary HGF has been associated with more severe respiratory disease. OBJECTIVES: We studied the protein expression of HGF and its receptor c-met during the perinatal period in the human lung. METHODS: Immunohistochemistry for HGF and c-met was performed on lung tissues from autopsies of 4 fetuses, 5 preterm infants, 5 term infants, and 4 infants with bronchopulmonary dysplasia. RESULTS: Immunohistochemistry for HGF showed staining in all cases in mesenchymal cells (fibroblasts and cartilage cells). Additional staining was found in bronchial and distal airway epithelium. Immunohistochemistry for c-met showed staining in bronchial and distal airway epithelium, and in most cases in neutrophils. CONCLUSIONS: The consistent expression of HGF and c-met during the perinatal period supports a physiological role for HGF in human lung development.
Assuntos
Fator de Crescimento de Hepatócito/metabolismo , Pulmão/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Aborto Espontâneo , Cadáver , Feto , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Pulmão/embriologia , Pulmão/patologiaRESUMO
Apoptosis is a highly conserved form of cell death present in all eukaryotic cell types and controlled by multiple genes. Several methods have been developed to quantify apoptosis, but none is adapted for all cell types. It is particularly difficult to reliably assay apoptosis of adherent cells. We describe a new, rapid and reliable flow cytometric method which can be used for quantifiying apoptosis in a sub-population of transiently transfected adherent cells. This technique is based on the detection of transfected cells and the apoptotic sub-population by immunofluorescence and Annexin-V labelling, respectively.
Assuntos
Apoptose , Citometria de Fluxo/métodos , Animais , Anexina A5/metabolismo , Apoptose/genética , Antígenos CD2/genética , Antígenos CD2/metabolismo , Adesão Celular , Linhagem Celular , Imunofluorescência , Genes bcl-2 , Genes p53 , Humanos , Camundongos , Ratos , TransfecçãoRESUMO
Cyclooxygenases-1 and -2 are the key enzymes in the conversion of arachidonic acid to prostanoids. Cyclooxygenase-2 (COX-2) takes part both in inflammation and in control of cell growth. COX-2 immunohistochemistry was performed on lung tissues from autopsies, with four groups included: fetuses (n = 4, GA = 16.0 to 32.0 wk), preterm infants (n = 10, GA = 23.0 to 29.9 wk), term infants (n = 6, GA = 38.7 to 42.0 wk), and infants with bronchopulmonary dysplasia (BPD) (n = 4, GA = 28.9 to 30.7 wk). COX-2 staining occurred exclusively in the epithelial cells resembling type II pneumocytes in the alveolae, and in ciliated epithelial cells in the bronchi. In fetuses, moderate intensity alveolar staining was seen in 90-100% cells lining the alveolar epithelium. In preterm infants, high intensity alveolar staining was seen in a scattered pattern. In term infants, the alveolar staining was also scattered, but with a lower proportion of positive cells. In BPD no staining appeared in alveolar epithelial cells. The most intense bronchial staining was found in fetuses and the least intense in term infants; staining was also seen in BPD. COX-2 is present in human perinatal lung from the gestational age of 16 wk, in a changing pattern. We suggest that COX-2 may, in addition to participating in inflammation, also play a developmental role in the perinatal lung.
Assuntos
Recém-Nascido Prematuro/metabolismo , Recém-Nascido de muito Baixo Peso/metabolismo , Isoenzimas/metabolismo , Pulmão/enzimologia , Pulmão/patologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Brônquios/enzimologia , Brônquios/patologia , Displasia Broncopulmonar/enzimologia , Displasia Broncopulmonar/patologia , Ciclo-Oxigenase 2 , Idade Gestacional , Humanos , Imuno-Histoquímica , Recém-Nascido , Pulmão/citologia , Proteínas de Membrana , Alvéolos Pulmonares/enzimologia , Alvéolos Pulmonares/patologia , Mucosa Respiratória/enzimologia , Mucosa Respiratória/patologiaRESUMO
Induction of apoptosis is a function of both an external stimulus and the physiology of the cell, which includes the expression of multiple oncogenes and tumor suppressors. Here we have studied the apoptotic response of immortalized mouse fibroblasts to serum withdrawal. We show that, in addition to the p53-independent apoptosis observed in p53- cells, overexpression of wild-type p53 tumor suppressor results in a high rate of programmed cell death. However, physiological range, low levels of the p53 protein protect fibroblasts from induction of apoptosis. Our results indicate that, as a function of its dose, the wild-type p53 can either protect from death or promote apoptosis. This new, anti-apoptotic, activity of p53 may have implications for the understanding of the role played by p53 in embryonic development as well as in initial stages of oncogenesis.
Assuntos
Apoptose/genética , Proteína Supressora de Tumor p53/metabolismo , Células 3T3 , Animais , Divisão Celular/genética , Linhagem Celular Transformada , Meios de Cultura Livres de Soro , Camundongos , Camundongos Endogâmicos BALB C , Fenótipo , Proteína Supressora de Tumor p53/genéticaRESUMO
UNLABELLED: Therapy with inhaled nitric oxide is usually given with high concentrations of oxygen. As nitric oxide (NO) is a free radical and hyperoxia increases oxygen radical production, we examined the effect of short exposure to NO or oxygen (O2) or both, on free radical-mediated changes in macromolecules, i.e. lipids and proteins, in vivo. Wistar rats were exposed to > 95% O2 or 40 ppm NO, or both, for 6 h. Rats in 21% O2 served as controls. Lipid peroxidation was quantified as expired pentane, oxidative protein modification as carbonyl concentration, and pulmonary neutrophil accumulation as myeloperoxidase activity in the lungs. Hyperoxia for 6 h caused higher expired pentane (4.83 +/- 1.39 pmol/min/100 g) and protein carbonylation (15.91 +/- 2.49 nmol/mg) compared to controls (2.26 +/- 1.00 pmol/min/100 g, and 7.40 +/- 1.12 nmol/mg, respectively; both p < 0.05). After exposure to NO in air, protein carbonylation (14.50 +/- 5.44 nmol/mg) and myeloperoxidase activity (4.85 +/- 1.52 mU/mg) were higher than in controls (myeloperoxidase 2.49 +/- 0.56 mU/mg; both p < 0.05). NO with hyperoxia decreased pentane (2.56 +/- 1.51 pmol/min/ 100 g) and protein carbonylation (11.38 +/- 3.58 nmol/mg) compared to hyperoxia (both p < 0.05). CONCLUSION: In vivo, 6 h exposure to hyperoxia or to 40 ppm NO induces free radical-mediated lung injury. The combination of hyperoxia and 40 ppm NO significantly attenuates free radical-mediated effects in the lungs compared to hyperoxia or 40 ppm NO in air.
Assuntos
Sequestradores de Radicais Livres/uso terapêutico , Hiperóxia/metabolismo , Pneumopatias/prevenção & controle , Óxido Nítrico/uso terapêutico , Oxigênio/uso terapêutico , Animais , Feminino , Peroxidação de Lipídeos , Pulmão/enzimologia , Pneumopatias/fisiopatologia , Estresse Oxidativo , Ratos , Ratos WistarRESUMO
Mussels (Mytilus edulis) and clams (Ruditapes philippinarum) were contaminated experimentally using cultures of Alexandrium minutum, a toxic dinoflagellate isolated from French coastal waters. Experiments were carried out in continually flushed and open-circuit systems using Alexandrium densities of 100 to 700 cells/ml delivered to tanks containing the shellfish. All experiments indicated an inversion of the relative proportions of gonyautoxins (GTX2 and GTX3) in shellfish meat during decontamination, whereas saxitoxin (STX) only accumulated during mussel depuration. However, in mussels a density as low as 100 cells/ml led within 10 days to bioaccumulation of paralytic shellfish poisoning (PSP) toxins above the public health threshold. Similar results were observed in clams subjected to fivefold higher cell densities, indicating a less effective assimilation of the dinoflagellate than by mussel. Decontamination experiments on PSP toxin-contaminated mussels (360 micrograms STX eq./100 g or lower uptake) fed two nontoxic diets (1,000 and 10,000 cells/ml of Tetraselmis suesica) showed an appreciable reduction in the time needed to decrease toxin concentration below the accepted threshold for human consumption. We suggest that a simple relation can be established between initial toxicity, the concentration of nontoxic alga available, and the time required for depuration once decontamination kinetics becomes linear and corresponds to the inverse of contamination kinetics.
Assuntos
Bivalves/metabolismo , Dinoflagellida/metabolismo , Toxinas Marinhas/metabolismo , Animais , Meios de Cultura , Contaminação de Alimentos , Doenças Transmitidas por Alimentos , França , Hidrólise , Cinética , Toxinas Marinhas/toxicidade , Saxitoxina/análogos & derivados , Saxitoxina/metabolismo , Saxitoxina/toxicidadeRESUMO
OBJECTIVES: Matrix metalloproteinases (MMPs) are a family endoproteinases that act in degradation of extracellular matrix and basement membranes. The development of bronchopulmonary dysplasia (BPD) is characterized by early pulmonary inflammation, increased microvascular permeability, and subsequently by disordered repair. The aims of our study were to characterize the presence and molecular weight forms of MMP-2, -8, and -9 and their specific inhibitor, tissue inhibitor of metalloproteinases (TIMP)-2, in lungs of preterm infants during the early postnatal period and to determine whether levels of these MMPs and TIMP-2 in tracheal aspirate fluid (TAF) are associated with acute or chronic lung morbidity of the preterm infant. METHODS: TAF samples were collected from 16 intubated preterm infants (gestational age 27.0 +/- 2.0 weeks; birth weight 875 +/- 246 g) during their first 5 postnatal days. The presence and molecular weight forms of MMPs and TIMP-2 were identified by Western immunoblotting, and their levels were evaluated by densitometric scanning. RESULTS: MMP-8 in TAF was higher in infants who needed treatment with surfactant (25.4 +/- 6.3 vs 10.6 +/- 1.5 arbitrary unit/secretory component of immunoglobulin A [AU/SC]) and in whom BPD developed (N = 6; 27.6 +/- 5.2 vs 15.1 +/- 5.0 AU/SC). TIMP-2 levels were lower in infants with initial arterial to alveolar oxygen tension ratios <0.22 (2.7 +/- 1.1 vs 16.8 +/- 7.4 AU/SC) and in infants needing mechanical ventilation for >1 week (5.2 +/- 2.1 vs 22.8 +/- 11.7 AU/SC). CONCLUSIONS: In preterm infants, an imbalance between pulmonary MMP-8 and TIMP-2 participates in the acute inflammatory process in respiratory distress syndrome and may contribute to the development of chronic lung injury.
Assuntos
Metaloproteinase 2 da Matriz/análise , Metaloproteinase 8 da Matriz/análise , Metaloproteinase 9 da Matriz/análise , Síndrome do Desconforto Respiratório do Recém-Nascido/enzimologia , Inibidor Tecidual de Metaloproteinase-2/análise , Traqueia/enzimologia , Displasia Broncopulmonar/enzimologia , Exsudatos e Transudatos/enzimologia , Feminino , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
The aim of the study was to examine the relationship between the plasma concentration of cyclic guanosine monophosphate (cGMP) and pulmonary pressure and hypoxia defined by oxygenation index (OI) in newborn infants with severe persistent pulmonary hypertension (PPHN) on inhaled nitric oxide (NO). In this prospective study, 18 newborn infants having Doppler ultrasound-diagnosed PPHN and treated with NO were investigated. The ratio of pulmonary artery to systemic artery pressure (PAP/SAP) and OI was assessed before treatment and at 0.5, 1, 12, and 24 h from the beginning of NO. At these time points, plasma concentrations of cGMP could be determined in 11 patients. The association of birth asphyxia as assessed by Apgar 1 min and 5 min and plasma cGMP before the NO treatment was examined. The initial median plasma concentration of cGMP was 37.3 pmol/ml (IQR 13.3-79.6). After the start of NO, cGMP increased significantly within 60 min (p = 0.003) and peaked at 12 h. Initial plasma cGMP was associated with Apgar score (1 and 5 min). OI decreased within 30 min of NO and PAP/SAP within 60 min. Persistent high PAP/SAP after 1 h of NO was associated with low cGMP concentration (r = 0.70, p = 0.02). We conclude that a significant increase in plasma cGMP is already evident after 60 min of NO therapy. This effect is accompanied by changes in oxygenation index and in pulmonary artery pressure. Initial plasma concentrations of cGMP were associated with hypoxia assessed as Apgar score.