RESUMEN
AIM: Recent clinical experience suggests that minimal access portoenterostomy (the Kasai procedure) for biliary atresia leads to transplantation sooner, compared to the traditional open approach. It should be emphasized that elevated intra-abdominal pressure (IAP) may reduce hepatic and portal blood flow and thus may cause histologic liver damage. The aim of the present study was to evaluate the effects of IAP on blood flow in the portal vein (PV), compared to the superior mesenteric artery (SMA), and on the systemic mean arterial blood pressure (MABP). MATERIALS AND METHODS: Male Sprague-Dawley rats were anesthetized with intraperitoneal ketamine (90 mg per kg) and xylasine (13 mg per kg). Polyethylene catheters (PE-50) were introduced into the right carotid artery for the measurement of MABP. After a midline laparotomy, the SMA and PV were isolated. Ultrasonic blood-flow probes were placed on the vessels for the continuous measurement of regional blood flow. Two large-caliber percutaneous peripheral intravenous catheters were introduced into the peritoneal cavity for inflation of air and for the measurement of IAP. The time course of MABP and SMA and PV flow as well as the relationship between IAP and SMA and PV flow were determined. RESULTS: Although all three hemodynamic parameters decreased with the increase in the IAP, the most significant changes were observed in PV blood flow. IAP at 3 mm Hg resulted in a 26% decrease in PV flow (P < 0.05), a 19% decrease in SMA flow (P < 0.05), and an 11% decrease in MABP (P < 0.05). IAP at 6 mm Hg caused a two-fold decrease in PV flow (P < 0.05), a 30% decrease in SMA flow (P < 0.05), and a 19% decrease in MABP (P < 0.05). There were no changes in the time course of MABP and PV and SMA flow. PV and SMA flow returned to normal values immediately after abdominal deflation. CONCLUSIONS: Persistent IAP decreased MABP, SMA, and, especially, PV flow by 50%. We speculate that in biliary atresia patients with already present liver dysfunction, decrease in SMA flow and even a greater decrease in PV flow from increased IAP, which occurs during a laparoscopic Kasai procedure, may further compromise liver function. This may be one of the explanations for the progression to earlier transplantation in infants undergoing a laparoscopic Kasai procedure.
Asunto(s)
Cavidad Abdominal/fisiología , Arterias Mesentéricas/fisiología , Vena Porta/fisiología , Animales , Presión Sanguínea/fisiología , Masculino , Presión , Ratas , Ratas Sprague-Dawley , Flujo Sanguíneo Regional/fisiologíaRESUMEN
Recent evidence suggests that neutrophil recruitment may initiate germ cell apoptosis in the ischemic testis. The purpose of the present study was to examine the relationship between germ cell apoptosis and neutrophil recruitment in the contralateral testis following testicular ischemia-reperfusion (IR) injury in a rat. Adult male Sprague-Dawley rats were divided randomly into two experimental groups: Group A: Sham operated animals; Group B: IR rats underwent 90 min of unilateral testicular ischemia following by 96 h of reperfusion. The rats were sacrificed and testes were harvested. Johnsen's criteria and the number of germinal cell layers were measured to categorize the spermatogenesis. TUNEL assay was used to determine germ cell apoptosis in both the ischemic and contralateral testis. The recruitment of neutrophils was calculated per 100 venules. Expression of E-selectin was determined using immunohistochemical analysis. Statistical analysis was performed using Student's t test, with P less than 0.05 considered statistically significant. Germ cell apoptosis in both the ischemic and the contralateral testis increased significantly after IR. E-selectin expression was significantly greater in ischemic testis from IR rats compared to sham animals. The small increase in E-selectin expression and the concomitant increase in neutrophil recruitment in the contralateral testis of the IR rats (vs. sham animals) were not statistically significant. In conclusion, testicular ischemia causes an increase in germ cell apoptosis in the contralateral testis. Mechanisms other than neutrophil recruitment apparently initiate this process.
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Selectina E/biosíntesis , Células Germinativas/patología , Infiltración Neutrófila , Daño por Reperfusión/patología , Enfermedades Testiculares/patología , Testículo/patología , Animales , Apoptosis , Modelos Animales de Enfermedad , Expresión Génica , Inmunohistoquímica , Etiquetado Corte-Fin in Situ/métodos , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/complicaciones , Daño por Reperfusión/fisiopatología , Espermatogénesis , Enfermedades Testiculares/etiología , Enfermedades Testiculares/fisiopatología , Testículo/irrigación sanguínea , Testículo/fisiopatologíaRESUMEN
In this study, we investigated the sensitivity, specificity, and predictive values of morphometric parameters of thyroideal follicular neoplasms based on concepts of fractal geometry. Thirty-seven follicular adenomas and 36 well-differentiated follicular carcinomas were assessed morphometrically. The nuclear area, nuclear area fraction, nuclear regularity factor, nuclear elongation factor, and slope setting (representing the ratio between the nuclear perimeter and nuclear regularity factor) were subjected to fractal dimensions analysis. By univariate analysis, the nuclear area, nuclear area fraction, nuclear regularity factor and slope values discriminate between adenomas and carcinomas. By multivariate analysis, the nuclear area, nuclear area fraction and slope values possess significant discriminatory powers in distinguishing between adenomas and carcinomas. Incorporating the nuclear area, nuclear area fraction, and slope values leads to a discriminatory power with 92% specificity and 83% sensitivity. The reciprocal relationships between the nuclear area, nuclear perimeter, and nuclear regularity factor of the cells of thyroideal adenomas and carcinomas may be expressed by fractal dimensions. Analysis limited to one parameter provides incomplete data. Expressing variations of the nuclear perimeter as a function of the nuclear regularity factor, the slope values constitute an independent attribute that significantly differentiates thyroideal adenomas from carcinomas.
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Adenocarcinoma Folicular/diagnóstico , Adenoma/diagnóstico , Fractales , Neoplasias de la Tiroides/diagnóstico , Adenocarcinoma Folicular/clasificación , Adenoma/clasificación , Núcleo Celular/patología , Diagnóstico Diferencial , Humanos , Procesamiento de Imagen Asistido por Computador , Análisis Multivariante , Valor Predictivo de las Pruebas , Neoplasias de la Tiroides/clasificaciónRESUMEN
Response of breast carcinomas to tamoxifen treatment depends, among others, on the estrogen receptor status. The estrogen receptor content was semiquantitatively determined in immunostained sections of stage 1 and 2 cancers of patients who had undergone tumor excision, tamoxifen treatment, adjuvant chemotherapy and radiotherapy. Weighted scores of the estrogen receptor content of the tumors were established by calculating the arithmetic means of the intensity of stained nuclei and the number of positively stained nuclei. Statistically, a cut-off value of > or = 2.1 signified a good prognosis; all patients whose tumors disclosed a weighted score of > or = 2.1 were alive and free of disease at the 10-year postoperative follow-up examination. On the other hand, one third of the patients whose carcinomas had a weighted score of < 2.1 presented with locally recurrent cancer, distant metastases, or both during the follow-up observation period. The statistically significant association between the patients' 10-year event-free survival and carcinomas with a weighted score of > or = 2.1 may serve oncologists in their decision making with respect to hormonal treatment.
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Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Receptores de Estrógenos/metabolismo , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/terapia , Interpretación Estadística de Datos , Supervivencia sin Enfermedad , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Recurrencia Local de Neoplasia/metabolismo , Pronóstico , Tamoxifeno/uso terapéuticoRESUMEN
Neuropilin-2 (NP-2) is a cell surface transmembrane protein originally characterized as a receptor for the type 3 semaphorins, and more recently for a number of vascular endothelial growth factor (VEGF) isoforms. NP-2 expression has been recently localized to a subset of neuroendocrine cells in the gastrointestinal tract. The aim of this study was to define the expression pattern of NP-2 in normal pancreatic islets and to determine the utility of NP-2 expression as a diagnostic marker of pancreatic endocrine tumours. Paraffin-embedded tissue sections from 30 endocrine pancreatic tumours (EPTs) and from normal pancreas were immunostained with a rabbit polyclonal antibody generated towards NP-2. Nineteen of the tumours were hormonally functional (nine insulinomas, nine gastrinomas, and one glucagonoma). The NP-2 staining pattern was correlated with islet cell hormone expression. In addition, NP-2 expression was evaluated in other normal neuroendocrine tissues and neuroendocrine neoplasms. In normal pancreas, NP-2 stained a distinct subset of islet cells situated primarily at the islet periphery. Double immunohistochemical staining revealed co-localization with glucagon-expressing cells. Moderate to strong NP-2 staining was present in 27 of 30 EPTs. Serial staining of the pancreatic tumours with insulin, gastrin, glucagon, pancreatic polypeptide (PP) or somatostatin did not reveal a distinct pattern of co-localization. NP-2 expression was not detected in neuroendocrine cells outside the gastroenteropancreatic system, or in their corresponding neoplasms, except for focal staining in one bronchial carcinoid tumour. In conclusion, the vast majority of EPTs examined expressed NP-2, suggesting its utility as a diagnostic marker for these tumours. The function of NP-2 in islet cell biology or tumourigenesis remains to be elucidated.
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Adenoma de Células de los Islotes Pancreáticos/metabolismo , Biomarcadores de Tumor/metabolismo , Islotes Pancreáticos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neoplasias Pancreáticas/metabolismo , Adenoma de Células de los Islotes Pancreáticos/diagnóstico , Diagnóstico Diferencial , Gastrinoma/diagnóstico , Gastrinoma/metabolismo , Glucagonoma/diagnóstico , Glucagonoma/metabolismo , Humanos , Técnicas para Inmunoenzimas , Insulinoma/diagnóstico , Insulinoma/metabolismo , Tumores Neuroendocrinos/diagnóstico , Tumores Neuroendocrinos/metabolismo , Neuropilina-1 , Neoplasias Pancreáticas/diagnóstico , Receptores de Superficie Celular/metabolismoRESUMEN
Laparoscopic cholecystectomy is now also performed for acute cholecystitis. In the presence of inflammatory conditions, technical difficulties leading to conversion to open cholecystectomy may occur and overshadow the advantages of the laparoscopic approach. Factors associated with these undue events combined with techniques capable of learning from them may help in determining when to completely avoid the laparoscopic procedure. In this study we determined predictors of conversion in acute cholecystitis and tested their predictive ability by means of statistical multivariate analysis and artificial neural networks. Between January 1994 and February 1997, 225 patients underwent laparoscopic cholecystectomy for acute cholecystitis. Preoperative and operative data were prospectively collected on standardized forms. The first 180 laparoscopically approached cases entered the training set, which was learned by both the statistical and the artificial neural networks methods. Conversion was first studied in relation to a set of preoperative data. Prediction models were then fitted by both of these methods. The last 45 operated cases, which remained unknown to the learning systems, served for testing the fitted models. The forward stepwise logistic regression technique, the forward stepwise linear discriminant analysis, and the artificial neural networks method enabled positive prediction of conversion in 0%, 27%, and 100% of the cases, and a negative prediction in 80%, 85.5%, and 97% respectively, in the training set. A positive prediction of conversion in 0%, 25%, and 67% of the cases, and a negative prediction in 82%, 88%, and 94%, respectively, in the untrained, validation set of patients. An artificial neural networks based model provides a practical tool for the prediction of successful laparoscopic cholecystectomies and their conversion. The high degree of certainty of prediction in untrained cases reveals its potential, and justifies, under appropriate conditions, the complete avoidance of laparoscopy and turning directly to open cholecystectomy.
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Colecistectomía Laparoscópica , Colecistectomía , Colecistitis/cirugía , Redes Neurales de la Computación , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Prospectivos , Análisis de Regresión , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: In studying patients with chronic fatigue syndrome (CFS) we developed a method that confers numerical expression to the degree of blood pressure and heart rate lability, ie, the 'hemodynamic instability score' (HIS). The HIS in CFS patients differed significantly from healthy subjects. The present investigation compares the HIS in CFS, non-CFS chronic fatigue and patients with recurrent syncope. METHODS: Patients with CFS (n = 21), non-CFS chronic fatigue (n = 24), syncope of unknown cause (n = 44), and their age and sex-matched healthy controls (n = 21) were evaluated with a standardized head-up tilt test (HUTT). Abnormal reactions (endpoints) on HUTT were classified 'clinical outcomes' (cardioinhibitory or vasodepressor reaction, orthostatic hypotension, postural tachycardia syndrome) and 'HIS endpoint', i.e. HIS >-0.98. RESULTS: The highest incidence of endpoints was noted in patients with CFS (79%), followed by patients with syncope of unknown cause (46%), non-CFS chronic fatigue (35%), and healthy subjects (14%). Presyncope or syncope during tilt occurred in 38% of CFS patients, 21% of patients with non-CFS chronic fatigue, and 43% of patients with recurrent syncope. The average HIS values were: CFS = +2.02 (SD 4.07), non-CFS chronic fatigue = -2.89 (SD 3.64), syncope = -3.2 (SD 3.0), healthy = -2.48 (4.07). The odds ratios for CFS patients to have HIS >-0.98 was 8.8 compared with non-CFS chronic fatigue patients, 14.6 compared with recurrent syncope patients, and 34.8 compared with healthy subjects. CONCLUSION: The cardiovascular reactivity in patients with CFS has certain features in common with the reactivity in patients with recurrent syncope or non-CFS chronic fatigue, such as the frequent occurrence of vasodepressor reaction, cardioinhibitory reaction, and postural tachycardia syndrome. Apart from to these shared responses, the large majority of CFS patients exhibit a particular abnormality which is characterized by HIS values >-0.98. Thus, HIS >-0.98 lends objective criteria to the assessment of CFS.