Metarhizium anisopliae sensu lato (s.l.) oil-in-water emulsions drastically reduced Rhipicephalus microplus larvae outbreak population on artificially infested grass.

Rhipicephalus microplus Canestrini, 1887 (Arachnida: Ixodidae) is a mandatory bloodsucking ectoparasite, and it is considered one of the main sanitary problems in livestock. In the development of new technologies for controlling ticks, Metarhizium anisopliae complex (M. anisopliae s. l.) Sorokin, 1883 (Ascomycota: Clavicipitaceae) have been shown to be an effective and safe alternative. However, when applied in the field, abiotic factors may directly influence their microbial activity, and different oily adjuvants enhance fungal efficacy, stability and viability under environmental conditions. Here, the efficacy of two Metarhizium anisopliae s.l. isolates (CG 148 and CG 347) were compared in mineral oil (MO) or vegetable oil (VO) emulsions to control cattle ticks under semi-natural conditions, as well as their persistence in the soil over time. Engorged female ticks were placed on the soil of grass pots previously treated or not with conidial oil-in-water emulsions. Both M. anisopliae s.l. oil-in-water emulsions tested were able to control R. microplus, achieving up to 100% daily efficacy, and remained viable in the soil for up to 60 days after treatment. These results show the prospective applicability of Metarhizium spp. to control the cattle tick and a real possibility for its control in the environment.

Collagen and elastic content of abdominal skin after surgical weight loss.

BACKGROUND: Collapsed skin folds after bariatric weight loss are often managed by plastic procedures, but changes in dermal composition and architecture have rarely been documented. Given the potential consequences on surgical outcome, a prospective histochemical study was designed. The hypothesis was that a deranged dermal fiber pattern would accompany major changes in adipose tissue. METHODS: Female surgical candidates undergoing postbariatric abdominoplasty (n=40) and never obese women submitted to control procedures (n=40) were submitted to double abdominal biopsy, respectively in the epigastrium and hypogastrium. Histomorphometric assessment of collagen and elastic fibers was executed by the Image Analyzer System (Kontron Electronic 300, Zeiss, Germany). RESULTS: Depletion of collagen, but not of elastic fibers, in cases with massive weight loss was confirmed. Changes were somewhat more severe in epigastrium (P=0.001) than hypogastrium (P=0.007). Correlation with age did not occur. CONCLUSIONS: (1) Patients displayed lax, soft skin lacking sufficient collagen fiber network. (2) Elastic fiber content was not damaged, and was even moderately increased in epigastrium; (3) Preoperative obesity negatively correlated with hypogastric collagen concentration; (4) Future studies should pinpoint the roles of obesity, and especially of massive weight loss, on dermal architecture and response to surgery.

DNA polymorphisms as tools for spinal cord injury research.

STUDY DESIGN: Data mining of single nucleotide polymorphisms (SNPs) in gene pathways related to spinal cord injury (SCI). OBJECTIVES: To identify gene polymorphisms putatively implicated with neuronal damage evolution pathways, potentially useful to SCI study. SETTING: Departments of Psychiatry and Orthopedics, Faculdade de Medicina, Universidade de São Paulo, Brazil. METHODS: Genes involved with processes related to SCI, such as apoptosis, inflammatory response, axonogenesis, peripheral nervous system development and axon ensheathment, were determined by evaluating the 'Biological Process' annotation of Gene Ontology (GO). Each gene of these pathways was mapped using MapViewer, and gene coordinates were used to identify their polymorphisms in the SNP database. As a proof of concept, the frequency of subset of SNPs, located in four genes (ALOX12, APOE, BDNF and NINJ1) was evaluated in the DNA of a group of 28 SCI patients and 38 individuals with no SC lesions. RESULTS: We could identify a total of 95,276 SNPs in a set of 588 genes associated with the selected GO terms, including 3912 nucleotide alterations located in coding regions of genes. The five non-synonymous SNPs genotyped in our small group of patients, showed a significant frequency, reinforcing their potential use for the investigation of SCI evolution. CONCLUSION: Despite the importance of SNPs in many aspects of gene expression and protein activity, these gene alterations have not been explored in SCI research. Here we describe a set of potentially useful SNPs, some of which could underlie the genetic mechanisms involved in the post trauma spinal cord damage.

The aetiological agents of American cutaneous leishmaniasis in the municipality of Monte Negro, Rondônia state, western Amazonia, Brazil.

Although American cutaneous leishmaniasis (ACL) is one of the most important endemic diseases in the Brazilian state of Rondônia, there is very little information on the species of parasite involved. The objective of the present study was to identify the Leishmania species causing ACL in the Monte Negro municipality of the state. Over a 6-year period (1997-2002), the skin lesions of 233 patients were examined while the patients were attending an outpatients' clinic at the University of São Paulo's Advanced Research Unit in Monte Negro. ACL was diagnosed in 137 (58.8%) of the patients and leishmanial parasites were successfully isolated from 14 of the ACL cases. Using a panel of 24 monoclonal antibodies, 12 of the 14 isolates were identified, as L. (Viannia) braziliensis (seven), L. (V.) lainsoni (one), a L. (V.) lainsoni-like species (two), a L. (V.) guyanensis-like species (one), or a L. (Viannia) species that was different from all named species (one). These are the first records of human infection with L. (V.) braziliensis and L. (V.) lainsoni in Rondônia.

WITHDRAWN: Association between polymorphisms in genes of inflammatory response and axonal repair with spinal cord injury.

Ahead of Print article withdrawn by publisher. Please see re-submitted article 'DNA polymorphisms as tools for spinal cord injury research' Spinal Cord advance online publication, 20 May 2008; doi:10.1038/sc.2008.67.

Colletotrichum gloeosporioides can overgrow Colletotrichum kahawae on green coffee berries first inoculated with C. kahawae.

Colletotrichum gloeosporioides is a weak pathogen of coffee that infects ripe berries at dark red stage causing necrotic lesions, but only penetrates up to the second superficial layers of the pericarp at the rose and pink stages. C. kahawae, the causal agent of coffee berry disease (CBD) and responsible for 70-80% of crop loss, infects berries at any stage of development. When green berries are first inoculated with C. kahawae and then at 2, 72 or 96 h later with C. gloeosporioides, the necrotic lesions were significantly larger than in the controls, and were much more evident when the berries were incubated at the optimum growth temperature of 28 degrees C for C. gloeosporioides. Isolations from the lesions induced by the first inoculations with C. kahawae followed by inoculation with C. gloeosporioides revealed that all or most of the time the recovered isolates of the latter. Thus, C. gloeosporioides can overwhelm C. kahawae under conditions of higher environmental temperature and humidity and may enhance the CBD infection process under field conditions.

The value of teaching sectional anatomy to improve CT scan interpretation.

A specific course on sectional anatomy was developed to help medical students improve their knowledge of cross-sectional imaging. The educational methodology consists of identifying anatomical structures displayed in plastinated sections from human cadavers and corresponding anatomical structures in computed tomography (CT) sections from healthy patients. The course has a self-study format. To assess and verify the impact of learning sectional anatomy on radiological knowledge, students were asked to identify ten anatomical structures in CT images. This test was applied to two groups of students: Group I had been taught sectional anatomy with CT images 2 years before the test; Group II had not received instruction in sectional anatomy prior to the test. Analysis of the results revealed a significant difference in test scores (median percentages of correctly identified structures) between Group I and Group II, with scores of 100% and 63.4%, respectively. These results provide evidence that the inclusion of sectional anatomy training in medical school curricula has a great impact on subsequent CT interpretation.

Differences in tumour growth, tumour cell proliferation and immune function after laparoscopy and laparotomy in an animal model.

BACKGROUND: Clinical and experimental studies have shown that laparoscopy preserves the immune response and can give better clinical results than laparotomy. However, the use of laparoscopy for the treatment of cancer patients is still controversial due to the risk of port-site and haematogenous metastases and increased tumour growth. The purpose of this experimental study was to assess tumour growth and the mechanism of differential tumour behaviour after laparoscopy and laparotomy. METHODS: Seventy-five young, male Wistar rats were randomly assigned to one of two experiments. Experiment 1: 45 animals were inoculated subcutaneously with Walker carcinosarcoma 256 cells and were subdivided into three groups of 15 rats. Control group la was submitted to anaesthesia only, group 1b received carbon dioxide (CO(2)) pneumoperitoneum,while group 1c received a laparotomy. Animals were sacrificed on postoperative day (POD) 7; tumours were excised and weighed to evaluate tumour growth. Nucleolar organiser regions identified by silver staining (AgNORs) were analysed to evaluate cell proliferation. Experiment 2: 30 rats were submitted to the same procedures as before, with ten animals in each group (2a, 2b, 2c), and a delayed-type hypersensitivity response (DTH) was used to evaluate the immune function. RESULTS: The average tumour mass was 1.76 g in group 1a, 2.81 g in group 1b and 4.21 g in group 1c (p < 0.05). The AgNOR expression results were similar in the three groups. The immune function was better preserved in the control group (2a: average inflammatory area on POD1 = 106 mm(2) and on POD2 = 128.18 mm(2)), than in the pneumoperitoneum group (2b: average inflammatory area on POD1 = 79.75 mm(2) and on POD2 = 126.93 mm(2)); the worst results were in the laparotomy group (2c: average inflammatory area on POD1 = 33.33 mm(2) and on POD2 = 61.32 mm(2)).There were significant differences between groups 2a and 2c and between 2b and 2c. CONCLUSION: Laparotomy stimulates a greater tumour growth than CO(2) pneumoperitoneum, but there is no difference in tumour cell proliferation. The cellular immune function is better preserved in animals submitted to CO pneumoperitoneum than in the laparotomized animals. These results suggest a relationship between a weaker immune response and a greater tumour growth.

A comparative study of aging of the elastic fiber system of the diaphragm and the rectus abdominis muscles in rats.

In the present study the age-related changes of the striated muscle elastic fiber system were investigated in the diaphragm and rectus abdominis muscles of 1-, 4-, 8- and 18-month-old rats. The activation patterns of these muscles differ in that the diaphragm is regularly mobilized tens of times every minute during the entire life of the animal whereas the rectus abdominis, although mobilized in respiration, is much less and more irregularly activated. The elastic fibers were stained by the Verhoeff technique for mature elastic fibers. Weigert stain was used to stain mature and elaunin elastic fibers, and Weigert-oxone to stain mature, elaunin and oxytalan elastic fibers. The density of mature and elaunin elastic fibers showed a progressive increase with age, whereas the amount of oxytalan elastic fibers decreased in both diaphragm and rectus abdominis muscles and their muscular fasciae. These age-related quantitative and structural changes of the elastic fiber system may reduce the viscoelastic properties of the diaphragm and rectus abdominis muscles, which may compromise the transmission of tensile muscle strength to the tendons and may affect maximum total strength.

A comparative study of aging of the elastic fiber system of the diaphragm and the rectus abdominis muscles in rats

In the present study the age-related changes of the striated muscle elastic fiber system were investigated in the diaphragm and rectus abdominis muscles of 1-, 4-, 8- and 18-month-old rats. The activation patterns of these muscles differ in that the diaphragm is regularly mobilized tens of times every minute during the entire life of the animal whereas the rectus abdominis, although mobilized in respiration, is much less and more irregularly activated. The elastic fibers were stained by the Verhoeff technique for mature elastic fibers. Weigert stain was used to stain mature and elaunin elastic fibers, and Weigert-oxone to stain mature, elaunin and oxytalan elastic fibers. The density of mature and elaunin elastic fibers showed a progressive increase with age, whereas the amount of oxytalan elastic fibers decreased in both diaphragm and rectus abdominis muscles and their muscular fascias. These age-related quantitative and structural changes of the elastic fiber system may reduce the viscoelastic properties of the diaphragm and rectus abdominis muscles, which may compromise the transmission of tensile muscle strength to the tendons and may affect maximum total strength

Presence of apolipoprotein E epsilon4 allele in cerebral palsy.

The apolipoprotein E gene, which is located on chromosome 19, has three alleles (epsilon2, epsilon3, and epsilon4). Several recent publications associate the presence of the apolipoprotein E epsilon4 allele with the occurrence of neurologic diseases, and consider it a risk factor for the development of central nervous system affections. A group of 40 patients with cerebral palsy was studied and compared to a control group of 40 subjects, and higher occurrence of the allele epsilon4 in the group of subjects with cerebral palsy was observed. A significantly higher risk of developing cerebral palsy was demonstrated among those subjects with the apolipoprotein E epsilon4 allele.

Morphology and diameter of infrarenal aortic aneurysms: a prospective autopsy study.

PURPOSE: To determine the diameter and morphology of infrarenal aortic aneurysms in 78 fresh autopsy specimens. METHODS: To avoid underestimation of the arterial diameter postmortem and to re-establish aneurysm morphology, a device was designed and introduced into the vessel, inflated to 80 mm Hg, and the largest external diameter was measured. RESULTS: The ages of the individuals ranged from 40 to 97 yr (mean 70). Thirty-eight aneurysms were ruptured with diameters ranging from 5.3 to 17.0 cm (mean 7.97), and 40 aneurysms were nonruptured with variations in diameters from 2.8 to 6.1 cm, mean 4.02 cm (P<0.01). Fusiform aneurysms were more frequent, and when they ruptured their diameters were smaller than the diameters of the spherical aneurysms (P<0.05). Aneurysms ruptured more frequently in the posterior wall (67%) and in the inferior portion (61%). A mural thrombus was found at the site of rupture in 80% of the specimens. CONCLUSION: In our samples, rupture was found solely in those aneurysms with a diameter over 5.0 cm, ruptures occurred earlier in fusiform aneurysms, mural thrombus was not a protective factor, and finally, aneurysms ruptured mainly in the posterior and inferior portions.

Age related changes in the elastic fiber system of the interfoveolar ligament.

In order to evaluate age related changes of the elastic fiber system in the interfoveolar ligament, we studied the deep inguinal ring from 33 male cadavers aged from stillborn to 76 years. Selective and alternated staining methods for elastic fibers were performed to differentiate oxytalan, elaunin, and mature elastic fibers. We confirmed quantitative changes of the elastic fiber system with aging. There was a significant and progressive reduction of the oxytalan fibers (responsible for tissue resistance) and a significant increment in the mature elastic and elaunin fibers (responsible for tissue elasticity). Furthermore, there were structural changes in the thickness, shortness and curling of these mature elastic fibers. These changes induced loss of the elastic fiber function and loss of the interfoveolar ligament compliance. These factors predispose individuals to the development of indirect inguinal hernias that frequently emerge in adults and aged individuals, especially above the fifth decade.

The effects of early and delayed immunosuppression in experimental tracheal transplantation with omentopexy.

BACKGROUND/PURPOSE: Best results in experimental tracheal allotransplantation are obtained when metachronous revascularization by omentopexy and immunosuppression are used. Nevertheless, this method of revascularization implies in a 4-day period of ischemia to the graft. The aim of this study was to assess the influence of the 4-day period of ischemia on host sensitization as well as the effect of early or delayed immunosuppression on the outcome of the grafts. METHODS: Thirty rabbits were submitted to tracheal allotransplantation and divided according to position of the graft (orthotopic or heterotopic transplants) and the initiation of immunosuppression (early or delayed). The quality of the revascularization was evaluated by the identification of Indian ink, perfused through the abdominal aorta, inside the submucosal vessels. The outcome of the grafts was evaluated by histological analysis according to a semiquantitative scale of alterations. RESULTS: Grafts were better revascularized in heterotopic position. Grafts with late immunosuppression presented good outcome only when heterotopically positioned. No significant differences were observed in grafts placed heterotopically or orthotopically when immunosuppression was initiated early after the transplant. CONCLUSIONS: Transient ischemia produced by metachronous revascularization is not the single factor responsible for the histological alterations observed in tracheal allografts. These alterations probably also are produced by the activation of immune responses. This activation is more intense in more ischemic grafts, but can be suppressed by early administration of immunosuppression.

Age-related changes in the elastic fiber network of the human splenic capsule.

The structural arrangement of elastic fibers in the splenic capsule from 16 human cadavers ranging in age from 1 month to 76 years was studied by histologic sections stained with selective methods for elastin. In infants the elastic fibers of the splenic capsule were homogeneously intermingled with collagen fibers, an arrangement that stabilizes the capsule during spleen growth and enlargement. With aging, collagen fibers predominate in the outer capsular surface over elastic fibers with the latter more evident in the deep lamina of the splenic capsule. In elderly individuals, the elastic fibers shorten, fragment, and thicken. The progressive decrease in the amount of elastic fibers in the splenic capsule with aging may restrict splenic distention and contribute to involution of the spleen as one grows older.

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia: studies of lung glycogen content, elastic fiber density, and collagen content.

BACKGROUND/PURPOSE: A new noninvasive therapeutic strategy, which consisted of prenatal intraamniotic administration of porcine surfactant or dexamethasone, was previously used to prevent the functional and structural immaturity of lungs associated with congenital diaphragmatic hernia (CDH), and its effects on lung development were comparable with the changes induced by tracheal ligation (TL). The purpose of this study is to verify if this novel therapeutic modality has any effect in the elevated concentration of lung glycogen and altered contents of lung elastic fiber and collagen promoted by CDH. METHODS: A pilot study was performed to investigate in the rabbit model if the infused drugs in the amniotic cavity were aspirated by the CDH and non-CDH fetuses, and if there was correspondence between lung immaturity and high glycogen concentration in lung tissue. Experimental groups consisted of 50 pregnant rabbits that underwent surgery on gestational day 24 or 25 to create left-sided diaphragmatic hernias in 56 fetuses, which were divided in groups according to the procedures: CDH (n = 12), CDH plus TL (n = 16), CDH plus intraamniotic administration of Curosurf (40 mg, n = 12), and CDH plus intraamniotic administration of dexamethasone (n = 16). On gestational day 30, the fetuses were delivered by cesarean section, and 28 normal unoperated fetuses served as controls. The lungs were weighed and submitted to biochemical determination of glycogen, morphometric evaluation of elastic fibers, and colorimetric analysis of collagen. RESULTS: In all CDH and non-CDH fetuses of the pilot study, the amniotic content was massively aspirated into the lungs and trachea. There was an increase in lung glycogen content of fetuses at 24 days' gestation in comparison with 20-day gestational age fetuses, followed by a decrease in the near full-term fetuses. In the fetuses of the experimental groups, CDH decreased the lung weight to body weight ratios of lungs ipsilateral to the hernia. These changes were reversed by TL but not by intraamniotic administration of surfactant or dexamethasone. Lung glycogen concentrations in the lungs of CDH fetuses were significantly higher than those in the control group. These changes were reversed by intraamniotic administration of surfactant but not by dexamethasone administration or TL. In the lungs ipsilateral to the hernia, surfactant administration promoted a significant decrease in glycogen content to levels lower than control lungs. CDH promoted a decrease in the linear density of elastic fibers in both lungs, ipsilateral and contralateral to the hernia. This alteration was partially corrected by TL and surfactant administration, although dexamethasone administration had no effect. The concentrations of collagen in both lungs were increased significantly by CDH, and these alterations could not be reversed by TL. In the lungs ipsilateral to the hernia, intraamniotic administration of surfactant or dexamethasone promoted a significant decrease in the lung concentration of collagen but not to control levels. CONCLUSIONS: The positive effects of intraamniotic surfactant or dexamethasone administration on lung maturity of fetuses with CDH were observed. This therapy may be a substitute for TL.

Circumscribed lesion of the medial forebrain bundle area causes structural impairment of lymphoid organs and severe depression of immune function in rats.

Interactions between the immune system and the brain are a key element in the pathophysiology of diseases such as multiple sclerosis, neuroAIDS, and Alzheimer's, which affect large numbers of individuals and are associated with a high social cost. However, the neuroanatomical basis of brain-immune interactions has not been elucidated. We report that in Wistar rats of either sex bilateral electrolytic lesion of the medial forebrain bundle reduces body weight by 28% 7 days after lesioning, and causes widespread infections, aphagia, adypsia, structural damage to the lymphoid organs and heavy depression of T lymphocytes cytotoxicity. The following alterations occur in the immune system after those lesions: the weight of the thymus, spleen and lymphonodes is reduced by 77.9%, 49.1% and 48.4%, respectively. The thymus is atrophied and contains fewer lymphoid cells in the cortex than in the medulla. In the spleen the white pulp is reduced and lymphoid cells from periarteriolar zones and at the chords are almost absent. In lymph nodes cortical small lymphocytes are depleted and primary and secondary nodules and germinal centers all but disappear. Cytotoxicity of lymphocytes is reduced by 86.2% in the thymus, 77.6% in the spleen and 70.2% in lymph nodes. The critical area of lesion is at the medialmost portion of the medial forebrain bundle, at the preoptic area and rostral part of the anterior hypothalamus. We suggest that this area contains neural circuits that are crucial for keeping the structure of lymphoid organs and the functional integrity of the immune system.

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Lung surfactant deficiency contributes to the pathophysiology of congenital diaphragmatic hernia (CDH) and the high neonatal mortality rate. Acceleration of lung surfactant system maturation by prenatal administration of hormones has been described in animal models of CDH. However, in utero tracheal ligation (TL) is the best method to accelerate lung growth and reverse the pulmonary hypoplasia associated with CDH. Although this method offers promise, its application in humans is limited. The aim of this study was to investigate a new noninvasive therapeutic strategy, that is, the prenatal intraamniotic administration of exogenous porcine surfactant or dexamethasone, and compare it with the effects of TL in an animal model of CDH. METHODS: Twenty-four pregnant New Zealand rabbits underwent surgery on gestational day 24 or 25 to create CDH in 26 fetuses. Five groups of animals were studied: (1) Control, nonoperated fetuses (n=14), (2) CDH (n=6), (3) CDH plus TL (n 6), (4) CDH plus intraamniotic administration of Curosurf (40 mg; n=6), and (5) CDH plus intraamniotic infusion of dexamethasone (0.4 mg; n=8). On gestational day 30, the fetuses were delivered by cesarean section. Functional studies (lung hysteresis curves and lung distensibility), weight and volume of lungs, histopathologic and histomorphometric analysis of lungs were performed. RESULTS: The authors demonstrated that the hysteresis curve of CDH animals was shifted downward in comparison with controls. The analyses of curves standardized for lung weight indicated that intraamniotic administration of surfactant or dexamethasone improved lung compliance in comparison with controls and CDH fetuses, but TL had no effect on this parameter. Lung distensibility (maximum lung volume at 32 cm of water pressure per gram of lung) was reduced by CDH, but this parameter was increased by intraamniotic administration of drugs and not by TL (P< .05). CDH decreased the weight and volume of lungs (P< .05), and these changes were reversed only by TL, which prevented the herniation of the liver from the abdomen to the thorax. Histologically, CDH lungs treated with TL or intraamniotic administration of drugs demonstrated structural patterns similar to those of controls. Histomorphometric studies proved that CDH promoted significant thickening of septa walls (P< .05), and all the therapeutic methods could reverse this alteration to control values. The alveolar number per area in control lungs, CDH, and CDH plus TL lungs were similar, but in CDH plus surfactant and CDH plus dexamethasone lungs, the decreased number per area (P< .05) demonstrated that the alveolar airspace was increased. CONCLUSION: From these data the authors conclude that intraamniotic surfactant or dexamethasone administration is capable of preventing pulmonary hypoplasia in fetuses with CDH, and thus, this method may be a substitute for TL.

Métodos de prevención de las alteraciones estructurales pulmonares en la hernia diafragmática congénita. Estudio experimental con cirugía fetal / Preventive methods of the lung alterations in congenital diaphragmatic hernia. Experimental study with fetal surgery

La hipoplasia pulmonar es la causa de muerte en el 30 al 50 por ciento de los recién nacidos con hernia diafragmática congénita. La ligadura traqueal en el feto, previene esta alteración, estimulando el crecimiento de la vía aérea. El objetivo principal de este trabajo es investigar un método de prevención de la hipoplasia pulmonar, basado en la administración intraamniótica de drogas, pasible de ser utilizado en la especie humana. Fueron operadas 36 conejas en el día 24 de gestación. En el primer grupo de fetos se creó una hernia diafragmática. En otros tres grupos además de la hernia diafragmática se efectuaron tres procedimientos adicionales: a) ligadura traqueal b) administración intraamniótica de dexametasona c) administración intraamniótica de surfactante. Se tomó como grupo control a 14 fetos, no operados, en el día 30, se efectuó una cesarea y se procedió a canular la tráquea de todos los animales para medir los parámetros funcionales (curvas de histéresis y de compliance). Los pulmones fueron recolectados para estudios biométricos: peso, volúmen e histología (evaluación cualitativa) y estudios histomorfométricos: densidad de septos alveolares, número de alvéolos por mm y evaluación de la densidad de fibras elásticas y colágenas. Se observó que la hernia diafragmática provocó una disminución significativa en el peso y volúmen de ambos pulmones, con caída de la histéresis y la complacencia, espesamiento de los septos alveolares, disminución del contenido en fibras elásticas y aumento del colágeno. La administración de surfactante y corticoides intraamnióticos produjeron efectos similares a los de la ligadura traqueal, corrigiendo parcialmente las alteraciones pulmonares en los fetos con hernia diafragmática, presentando el surfactante efectos más acenntuados. Concluímos que la administración intraamniótica de surfactante o dexametasona pueden subsistir a la ligadura traqueal como método experimental de prevención de la hipoplasia pulmonar, presente en los fetos con hernia diafragmática congénita