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1.
J Endocrinol Invest ; 45(6): 1161-1172, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35072927

RESUMEN

PURPOSE: Female sexual response involves a complex interplay between neurophysiological mechanisms and the nitric oxide (NO)-mediated relaxation of clitoris and vagina. The aim of this study was to evaluate sex steroids regulation of the relaxant pathway in vagina, using a validated animal model. METHODS: Subgroups of OVX Sprague-Dawley rats were treated with 17ß-estradiol, testosterone, or testosterone and letrozole, and compared with a group of intact animals. Masson's trichrome staining was performed for morphological evaluation of the distal vaginal wall, in vitro contractility studies investigated the effect of OVX and in vivo treatments on vaginal smooth muscle activity. RNA from vaginal tissue was analyzed by semi-quantitative RT-PCR. RESULTS: Immunohistochemical analysis showed that OVX induced epithelial and smooth muscle structural atrophy, testosterone and testo + letrozole increased the muscle bundles content and organization without affecting the epithelium while 17ß-estradiol mediated the opposite effects. In vitro contractility studies were performed on noradrenaline pre-contracted vaginal strips from each experimental group. Acetylcholine (0.001-10 µM) stimulation induced a concentration-dependent relaxation, significantly reduced by NO-synthase inhibitor L-NAME and by guanylate cyclase inhibitor ODQ. OVX resulted in a decreased responsiveness to acetylcholine, restored by testosterone, with or without letrozole, but not by 17ß-estradiol. OVX sensitivity to the NO-donor SNP was higher than in the control. Vardenafil, a PDE5 inhibitor, enhanced SNP effect in OVX + testosterone as well as in control, as supported by RNA expression analysis. CONCLUSIONS: Our study demonstrates that testosterone improves the NO-mediated smooth muscle vaginal cells relaxation confirming its role in maintaining the integrity of muscular relaxant machinery.


Asunto(s)
Acetilcolina , Óxido Nítrico , Animales , Estradiol/farmacología , Femenino , Humanos , Letrozol/farmacología , Óxido Nítrico/metabolismo , Ovariectomía , ARN , Ratas , Ratas Sprague-Dawley , Testosterona/farmacología , Vagina/metabolismo
2.
J Endocrinol Invest ; 44(4): 819-842, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32772323

RESUMEN

PURPOSE: In both preclinical and clinical settings, testosterone treatment (TTh) of hypogonadism has shown beneficial effects on insulin sensitivity and visceral and liver fat accumulation. This prospective, observational study was aimed at assessing the change in markers of fat and liver functioning in obese men scheduled for bariatric surgery. METHODS: Hypogonadal patients with consistent symptoms (n = 15) undergoing 27.63 ± 3.64 weeks of TTh were compared to untreated eugonadal (n = 17) or asymptomatic hypogonadal (n = 46) men. A cross-sectional analysis among the different groups was also performed, especially for data derived from liver and fat biopsies. Preadipocytes isolated from adipose tissue biopsies were used to evaluate insulin sensitivity, adipogenic potential and mitochondrial function. NAFLD was evaluated by triglyceride assay and by calculating NAFLD activity score in liver biopsies. RESULTS: In TTh-hypogonadal men, histopathological NAFLD activity and steatosis scores, as well as liver triglyceride content were lower than in untreated-hypogonadal men and comparable to eugonadal ones. TTh was also associated with a favorable hepatic expression of lipid handling-related genes. In visceral adipose tissue and preadipocytes, TTh was associated with an increased expression of lipid catabolism and mitochondrial bio-functionality markers. Preadipocytes from TTh men also exhibited a healthier morpho-functional phenotype of mitochondria and higher insulin-sensitivity compared to untreated-hypogonadal ones. CONCLUSIONS: The present data suggest that TTh in severely obese, hypogonadal individuals induces metabolically healthier preadipocytes, improving insulin sensitivity, mitochondrial functioning and lipid handling. A potentially protective role for testosterone on the progression of NAFLD, improving hepatic steatosis and reducing intrahepatic triglyceride content, was also envisaged. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02248467, September 25th 2014.


Asunto(s)
Hipogonadismo , Grasa Intraabdominal , Metabolismo de los Lípidos/efectos de los fármacos , Hígado , Enfermedad del Hígado Graso no Alcohólico , Obesidad , Testosterona , Adulto , Biopsia/métodos , Estudios Transversales , Humanos , Hipogonadismo/diagnóstico , Hipogonadismo/tratamiento farmacológico , Hipogonadismo/epidemiología , Resistencia a la Insulina , Grasa Intraabdominal/efectos de los fármacos , Grasa Intraabdominal/metabolismo , Grasa Intraabdominal/patología , Italia/epidemiología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Obesidad/diagnóstico , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Sustancias Protectoras/administración & dosificación , Sustancias Protectoras/farmacocinética , Testosterona/administración & dosificación , Testosterona/farmacocinética , Resultado del Tratamiento
3.
J Endocrinol Invest ; 42(8): 951-965, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30674010

RESUMEN

BACKGROUND: Activation of the farnesoid X receptor (FXR), a member of the nuclear receptor steroid superfamily, leads to anti-inflammatory and anti-fibrotic effects in several tissues, including the lung. We have recently demonstrated a protective effect of the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) in rat models of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and bleomycin-induced pulmonary fibrosis. The aim of the present study was to investigate whether the positive effects of OCA treatment could be exerted also in established MCT-induced PAH, i.e., starting treatment 2 weeks after MCT administration. METHODS: Rats with MCT-induced PAH were treated, 2 weeks after MCT administration, with OCA or tadalafil for two additional weeks. Pulmonary functional tests were performed at week 2 (before treatment) and four (end of treatment). At the same time points, lung morphological features and expression profile of genes related to smooth muscle relaxation/contraction and tissue remodeling were also assessed. RESULTS: 2 weeks after MCT-induced injury, the treadmill resistance (a functional parameter related to pulmonary hypertension) was significantly decreased. At the same time point, we observed right ventricular hypertrophy and vascular remodeling, with upregulation of genes related to inflammation. At week 4, we observed a further worsening of the functional and morphological parameters, accompanied by dysregulation of inflammatory and extracellular matrix markers mRNA expression. Administration of OCA (3 or 10 mg/kg/day), starting 2 weeks after MCT-induced injury, significantly improved pulmonary function, effectively normalizing the exercise capacity. OCA also reverted most of the lung alterations, with a significant reduction of lung vascular wall thickness, right ventricular hypertrophy, and restoration of the local balance between relaxant and contractile pathways. Markers of remodeling pathways were also normalized by OCA treatment. Notably, results with OCA treatment were similar, or even superior, to those obtained with tadalafil, a recently approved treatment for pulmonary hypertension. CONCLUSIONS: The results of this study demonstrate a significant therapeutic effect of OCA in established MCT-induced PAH, improving exercise capacity associated with reduction of right ventricular hypertrophy and lung vascular remodeling. Thus, OCA dosing in a therapeutic protocol restores the balance between relaxant and contractile pathways in the lung, promoting cardiopulmonary protective actions in MCT-induced PAH.


Asunto(s)
Ácido Quenodesoxicólico/análogos & derivados , Modelos Animales de Enfermedad , Hipertensión Pulmonar/tratamiento farmacológico , Monocrotalina/toxicidad , Fibrosis Pulmonar/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/agonistas , Animales , Antibióticos Antineoplásicos/toxicidad , Bleomicina/toxicidad , Ácido Quenodesoxicólico/farmacología , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/patología , Masculino , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/patología , Ratas , Ratas Sprague-Dawley
4.
J Endocrinol Invest ; 42(3): 283-294, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29923060

RESUMEN

PURPOSE: We recently demonstrated a protective effect of the farnesoid X receptor agonist obeticholic acid (OCA) in rat models of bleomycin-induced pulmonary fibrosis (PF). Aim of the present study was to investigate whether the positive effects of OCA treatment are apparent also on ongoing bleomycin-induced PF, i.e., after 2 weeks of bleomycin administration. METHODS: Bleomycin-induced PF rats were treated 2 weeks after bleomycin administration with OCA or pirfenidone for two additional weeks. Pulmonary function test was performed at 2 and 4 weeks in all experimental groups. At the same time points, lung morphological features and mRNA expression profile of genes related to fibrosis, inflammation and epithelial-mesenchymal transition were also assessed. RESULTS: After 2 weeks, bleomycin significantly increased the pressure at the airway opening (PAO), a functional parameter related to fibrosis-induced lung stiffness, and induced diffuse lung interstitium fibrosis, with upregulation of inflammation (IL1ß, MCP1) and tissue remodeling (COL1A1, COL3A1, ET1, MMP7, PDGFa, αSMA, SNAI1) markers. At week four, a further increase of lung fibrosis and PAO was observed, accompanied by upregulation of extracellular matrix-related mRNA expression. OCA administration, even after the establishment of PF, significantly improved pulmonary function, normalizing PAO, and reverted the bleomycin-induced lung alterations, with significant reduction of markers of inflammation (CD206, COX2, HIF1, IL1ß, MCP1), epithelial proliferation (CTGF, PDGFa) and fibrosis (COL1A1, COL3A1, ET1, FN1, MMPs, αSMA, SNAIs, TGFß1, TIMPs). Results with OCA were similar or superior to those obtained with pirfenidone. CONCLUSIONS: In conclusion, our results demonstrate a significant therapeutic effect of OCA in already established PF.


Asunto(s)
Biomarcadores/metabolismo , Bleomicina/toxicidad , Ácido Quenodesoxicólico/análogos & derivados , Modelos Animales de Enfermedad , Transición Epitelial-Mesenquimal/efectos de los fármacos , Fibrosis Pulmonar/tratamiento farmacológico , Animales , Antibióticos Antineoplásicos/toxicidad , Ácido Quenodesoxicólico/farmacología , Masculino , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/metabolismo , Fibrosis Pulmonar/patología , Ratas , Ratas Sprague-Dawley
5.
Prostate ; 74(1): 10-28, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24037776

RESUMEN

BACKGROUND: BPH and LUTS have been associated to obesity, hypogonadism, and metabolic syndrome (MetS). MetS-induced prostate and bladder alterations, including inflammation and tissue remodeling, have been related to a low-testosterone and high-estrogen milieu. In addition to ERs, GPR30/GPER is able to mediate several estrogenic non-genomic actions. METHODS: Supplementing a subgroup of MetS rabbits with tamoxifen, we analyzed the in vivo effects on MetS-induced prostate and bladder alterations. The effects of selective ER/GPER ligands and GPER silencing on prostate inflammation were also studied in vitro using hBPH cells. RESULTS: ERα, ERß, and PR expression was upregulated in MetS bladder, where tamoxifen decreased ERα and PR expression, further stimulating ERß. In addition, tamoxifen-dosing decreased MetS-induced overexpression of inflammatory and tissue remodeling genes. In prostate, sex steroid receptors, pro-inflammatory and pro-fibrotic genes were upregulated in MetS. However, tamoxifen did not affect them and even increased COX-2. In hBPH cells, 17ß-estradiol increased IL-8 secretion, an effect blunted by co-treatment with GPER antagonist G15 but not by ER antagonist ICI 182,780, which further increased it. GPER agonist G1 dose-dependently (IC50 = 1.6 nM) induced IL-8 secretion. In vitro analysis demonstrated that GPER silencing reverted these stimulatory effects. CONCLUSIONS: GPER can be considered the main mediator of estrogen action in prostate, whereas in bladder the mechanism appears to rely on ERα, as indicated by in vivo experiments with tamoxifen dosing. Limiting the effects of the MetS-induced estrogen action via GPER could offer new perspectives in the management of BPH/LUTS, whereas tamoxifen dosing showed potential benefits in bladder.


Asunto(s)
Síndrome Metabólico/metabolismo , Próstata/metabolismo , Receptores de Estrógenos/fisiología , Receptores Acoplados a Proteínas G/fisiología , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Tamoxifeno/farmacología , Vejiga Urinaria/metabolismo , Animales , Línea Celular , Cromosomas Humanos Par 11/genética , Cromosomas Humanos Par 8/genética , Humanos , Masculino , Síndrome Metabólico/tratamiento farmacológico , Apareamiento , Próstata/efectos de los fármacos , Conejos , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Tamoxifeno/uso terapéutico , Vejiga Urinaria/efectos de los fármacos
6.
Recent Pat Anticancer Drug Discov ; 12(2): 148-168, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28164756

RESUMEN

BACKGROUND: Integrins are heterodimeric cell surface receptors that mediate cell-cell and cell-extracellular matrix adhesion. These molecules play a role in processes such as cell growth and proliferation, differentiation, migration, cell trafficking, besides contributing to angiogenesis and tumor development. Given their biological role, integrins have been proposed as amenable targets in medicinal chemistry. In particular, αvß3, αvß5, αvß6 and α5ß1, integrins involved in tumor angiogenesis and metastasis, have been the subject of studies aimed at the discovery of novel cancer therapeutics. A large number of peptides and peptidomimetics based on the RGD (Arg-Gly-Asp) recognition sequence were developed in the past two decades as integrin ligands. Though such ligands have not been satisfactory as anti-angiogenic agents, their use as tools to achieve selective tumor targeting of anticancer drugs has been explored. OBJECTIVE: In this review, we summarize recent literature and patent applications in which integrin peptidic and peptidomimetic ligands were conjugated to chemotherapeutic agents both with stable or cleavable bonds to achieve tumor targeted drug delivery. METHODS: Relevant recent patents and literature in this field have been considered spanning the search from 2000 to 2016. Literature and patents were examined according to the different classes of cytotoxic drug targeted to integrins. CONCLUSION: In spite of the promising features of the conjugates, none of them has entered clinical trials. New efforts are focused on innovative approaches in the field such as the synthesis of new integrin ligands able to target a single integrin type or the employment of nanoparticles based drug delivery systems.


Asunto(s)
Antineoplásicos/administración & dosificación , Integrinas/metabolismo , Neoplasias/tratamiento farmacológico , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Sistemas de Liberación de Medicamentos , Humanos , Nanopartículas , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/patología , Patentes como Asunto , Péptidos/administración & dosificación , Péptidos/química , Peptidomiméticos/administración & dosificación , Peptidomiméticos/química
7.
Pediatr Pulmonol ; 36(4): 322-9, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12950046

RESUMEN

The aim of this study was to investigate the effect of tidal liquid ventilation (TLV) compared to conventional mechanical ventilation (CMV) on oxidative lung damage in the setting of acute respiratory distress syndrome (ARDS). After repeated lung lavages, 10 minipigs were treated with CMV or TLV for 4 hr before the animals were sacrificed. Samples for blood gas analysis and bronchial aspirate samples were withdrawn before the induction of lung injury, and at 10 min, 2 hr, and 4 hr after the beginning of ventilatory support. To assess lung oxidative damage, total hydroperoxide (TH) and advanced oxidation protein product (AOPP) concentrations were measured in bronchial aspirate samples. After 2 and 4 hr of ventilatory support, partial oxygen tension (PaO(2)) and base excess (BE) were significantly higher in the TLV group than in the CMV group, while PaCO(2) was slightly higher, but with no statistical significance. In the CMV group, the AOPP level was significantly higher at 4 hr than at baseline. TH and AOPP bronchial aspirate concentrations were higher in the CMV group than in the TLV group at 2 and 4 hr of ventilation. We conclude that animals treated with TLV showed lower oxidative lung damage compared to animals treated with CMV.


Asunto(s)
Fluorocarburos/farmacología , Ventilación Liquida , Pulmón/patología , Estrés Oxidativo/efectos de los fármacos , Síndrome de Dificultad Respiratoria/patología , Animales , Femenino , Peróxido de Hidrógeno/sangre , Masculino , Intercambio Gaseoso Pulmonar/efectos de los fármacos , Respiración Artificial , Porcinos , Porcinos Enanos
8.
J Biomech ; 37(12): 1837-47, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15519592

RESUMEN

Knowledge of the mechanical behaviour of immature tracheae is crucial in order to understand the effects exerted on central airways by ventilatory treatments, particularly of Total Liquid Ventilation. In this study, a combined experimental and computational approach was adopted to investigate the compliance and particularly collapsibility of preterm lamb tracheae in the range of pressure likely applied during Total Liquid Ventilation (-30 to 30 cmH2O). Tracheal samples of preterm lambs (n = 5; gestational age 120-130 days) were tested by altering transmural pressure from -30 to 30 cmH2O. Inflation (Si) and collapsing (Sc) compliance values were calculated in the ranges 0 to 10 cmH2O and -10 to 0 cmH2O, respectively. During the tests, an asymmetric behaviour of the DeltaV/V0 vs. P curves at positive and negative pressure was observed, with mean Si = 0.013 cmH2O(-1) and Sc = 0.053 cmH2O(-1). A different deformed configuration of the sample regions was observed, depending on the posterior shape of cartilaginous ring. A three-dimensional finite-element structural model of a single tracheal ring, based on histology measurements of the tested samples was developed. The model was parameterised in order to represent rings belonging to three different tracheal regions (craniad, median, caudal) and numerical analyses replicating the collapse test conditions were performed to evaluate the ring collapsibility at pressures between 0 and -30 cmH2O. Simulation results were compared to experimental data to verify the model's reliability. The best model predictions occurred at pressures -30 to -10 cmH2O. In this range, a model composed of median rings best interpreted the experimental data, with a maximum error of 2.7%; a model composed of an equal combination of all rings yielded an error of 12.6%.


Asunto(s)
Feto/fisiología , Tráquea/fisiología , Animales , Fenómenos Biomecánicos , Adaptabilidad , Femenino , Feto/anatomía & histología , Edad Gestacional , Técnicas In Vitro , Ventilación Liquida , Modelos Anatómicos , Modelos Biológicos , Embarazo , Presión , Ovinos , Tráquea/anatomía & histología
9.
Arch Gerontol Geriatr ; 22 Suppl 1: 173-7, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-18653026

RESUMEN

Microalbuminuria is considered as a sign of high risk of renal disease in type 1 diabetes mellitus, and of cardiovascular disease in types 1 and 2 diabetes. In recent years numerous studies have suggested that microalbuminuria may be associated with atherosclerotic vascular disease, independently from diabetes mellitus. The presence of microalbuminuria was investigated in 30 patients suffering from atherosclerotic vascular disease: ischemic heart disease, cerebrovascular disease or arterial disease of the lower extremities. They were divided into two groups similar in age: 13 with type 2 diabetes mellitus, and 17 without diabetes. The aim of the research was to reveal eventually different prevalence of microalbuminuria in patients with vascular disease associated with diabetes or without diabetes. Microalbuminuria was present in 52.9% of the non diabetic patients and in 76.9% of the diabetics, but the difference did not reach statistical significance (in Mann-Whitney test p = 0.18; Chi-square test = 0.83; p = 0.3). No significant correlation was found between microalbuminuria and fibrinogen, total cholesterol, HDL-cholesterol and triglycerides. The hypertensive patients presented higher mean values of microalbuminuria than the normotensive ones (3.2 +/- 3.8 and 2.8 +/- 4.4 mg %, respectively), but the difference was again not significant (t = 0.25; p = 0.8). In the light of this research microalbuminuria seems to be a condition associated with atherosclerotic vascular disease, independently from the presence of diabetes mellitus and arterial hypertension.

10.
Med Eng Phys ; 25(3): 229-38, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12589721

RESUMEN

The partitioning of umbilical vein blood flow between fetal liver and ductus venosus may be an indicator of the fetal well-being, because the goal of the ductus venosus is to supply oxygen and nutrients to heart and brain. Both distribution and blood flow rate of the umbilical vein are functions of the local vascular impedances that, in turn, depend on the anatomical features of the related vessels. In order to investigate the venous blood flows in human fetuses during a normal gestation, a simple lumped parameter mathematical model was developed on the basis of some information achievable by ultrasonographic techniques. Particularly, the diameter and length of umbilical vein and ductus venosus and the volume of the liver were used to derive the vascular impedances. Three different impedance models were adopted for the umbilical vein, the ductus venosus and the hepatic circulation. A linear model described viscous hydraulic dissipations through the umbilical vein, while a quadratic pressure-flow relationship was used for the ductus venosus due to the irregular local hemodynamics at its inlet. Finally, the equivalent impedance of the whole hepatic network was related to the hepatic volume assuming a tree-like, symmetric and self-similar fractal geometry. The hepatic vascular resistances predicted according to the fractal analysis were quite consistent with some experimental measurements in fetal lambs. In agreement with clinical observations, the model predicted blood flows through the ductus venosus and umbilical vein increasing (from about 25 to 75 ml/min and from about 45 to 370 ml/min, respectively) throughout the gestation (20-40 weeks), while the flow fraction shunted via the ductus venosus diminishes (from about 50 to 20%).


Asunto(s)
Hígado/irrigación sanguínea , Hígado/fisiología , Modelos Cardiovasculares , Cordón Umbilical/fisiología , Venas Umbilicales/embriología , Venas Umbilicales/fisiología , Velocidad del Flujo Sanguíneo , Simulación por Computador , Desarrollo Embrionario y Fetal/fisiología , Sangre Fetal/fisiología , Feto/irrigación sanguínea , Feto/fisiología , Edad Gestacional , Hemorreología/métodos , Humanos , Hígado/embriología , Circulación Hepática/fisiología , Cordón Umbilical/embriología , Resistencia Vascular/fisiología , Vena Cava Inferior/embriología , Vena Cava Inferior/fisiología
11.
Ann Ital Med Int ; 6(4): 375-8, 1991.
Artículo en Italiano | MEDLINE | ID: mdl-1666516

RESUMEN

Hepatitis C virus (HCV) is responsible for a high percentage of cases of transfusional hepatitis and is often considered the etiological agent of numerous cases of non-A, non-B hepatitis in which parenteral transmission has not been documented. Patients undergoing hemodialysis are at risk for HCV infection. We used an immunoenzymatic method and confirmatory test (neutralization test) to determine serum anti-HCV antibody positivity in order to identify the factors associated with increased risk of HCV infection. We studied 63 hemodialyzed patients from eastern Sicily and compared the mean dialytic age and transfusion case history in positive and negative groups. 17.4 percent of the patients were anti-HCV positive. Mean dialytic age was significantly higher in the anti-HCV positive group. On the contrary no significant differences regarding transfusion case history or number of units of blood transfused were seen in the two groups. Our study confirms that hemodialyzed patients are at risk for HCV infection. This risk seems to increase with dialytic age. The lack of correlation between HCV and transfusion case history suggests that it may be a hospital-acquired infection.


Asunto(s)
Hepacivirus/inmunología , Anticuerpos Antihepatitis/sangre , Fallo Renal Crónico/inmunología , Diálisis Renal , Factores de Edad , Femenino , Humanos , Fallo Renal Crónico/terapia , Masculino , Prevalencia , Factores de Riesgo , Sicilia/epidemiología
12.
J Appl Biomater Biomech ; 2(3): 177-82, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-20803436

RESUMEN

Knowledge of immature tracheae mechanical behavior is fundamental in understanding the effects exerted on the upper airways by tidal liquid ventilation (TLV). Particularly, negative pressure can take place along the airways during expiration, which can cause airway collapse and flow limitation; therefore, representing a critical issue in preterm infant patients, whose airways are less stiff than adult ones. In this study, we investigated the expiratory pressure drop vs flow relationship of isolated preterm lamb tracheal samples to determine their hydraulic resistance, collapse pressure and collapse flow rate; a liquid flow through the samples was obtained by applying negative pressure at the outlet (cephalad) extremity of the tra-cheal sample, while keeping the inlet (caudal) extremity at atmospheric pressure. Histological analyzes were performed on the tracheal samples after each test session, in order to examine the morphological structure of the tracheal wall. Flow resistance tests demonstrated progressive lumen narrowing at increasing pressure drop (∆P=P in -P out ). The flow rate increased with ∆P un-til a plateau was reached, and then decreased, describing the onset of a collapse phenomenon; however, complete occlusion was not reached. The tracheal samples demonstrated a similar behavior to that of a Starling resistor during the collapse phase: when a critical ∆P was reached, collapse was observed starting at the outlet region, which was subjected to the greatest negative pressure, then propagating towards the caudal direction. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 177-82).

13.
Perfusion ; 22(5): 317-22, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18416216

RESUMEN

BACKGROUND: Given that there is an association between the degree of hemodilution during cardiopulmonary bypass (CPB) and postoperative complications, patients-outcome might be improved if the nadir hematocrit concentration is kept within an optimal range. Smaller patients are more likely to have a low hematocrit during CPB: this phenomenon may be related, at least partially, to the extreme hemodilution induced by a large fixed CPB priming volume. METHODS: Forty patients with a body surface area (BSA) < 1.7 m2 undergoing open heart operations were randomized to either standard CPB with full prime volume (control group) or reduced prime extracorporeal circuit and vacuum-assisted venous drainage (VAVD) (study group). RESULTS: There were no significant differences between the groups with respect to baseline characteristics, body surface area, hematologic profile and operative data. Clinical outcomes were similar. Nadir hematocrit and hemoglobin on bypass were significantly lower in the control group (22 +/- 2.3 vs. 24 +/- 2.5%, p < 0.02 and 7.4 +/- 0.7 vs. 8 +/- 0.9 g/dl, p < 0.04, respectively). Postoperative chest tube drainage was significantly higher in the control group (272 +/- 253 vs. 139 +/- 84 ml, p < 0.04). There was no difference in blood transfusion in the two groups (0.5 +/- 1.14 vs. 1.0 +/- 1.77 units of packed red blood cells (PRBC), p = 0.29). CONCLUSIONS: Lowering CPB priming volume by means of using a small oxygenator and vacuum-assisted venous drainage (VAVD) resulted in a significant decrease of intraoperative hemodilution. This technique should be strongly considered for patients with a small BSA (<1.7 m2) undergoing open heart surgery.


Asunto(s)
Tamaño Corporal , Puente Cardiopulmonar/métodos , Puente de Arteria Coronaria , Hemodilución/métodos , Anciano , Transfusión Sanguínea , Puente Cardiopulmonar/efectos adversos , Femenino , Hemodilución/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Resultado del Tratamiento
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