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Biomedical subjects

S Navarro

Publications and source records attributed to S Navarro.

At least 19 recordsLinked to original sources
PubMed2006

Neurosurgery at an earlier stage of Parkinson disease: a randomized, controlled trial.

BACKGROUND: Stimulation of the subthalamic nucleus is an effective treatment for advanced Parkinson disease (PD) and is currently performed after a mean disease duration of 14 years, when severe motor complications have resulted in marked loss of quality of life. We examined whether surgery at an early stage would maintain quality of life as well as improve motor function. METHODS: Twenty patients with PD of short duration (time elapsed since first symptom +/- SD: 6.8 +/- 1.0 years) with mild to moderate motor signs (Unified Parkinson's Disease Rating Scale III "off" medication: 29 +/- 12) who responded well to levodopa treatment were included in pairs, matched for age, duration and severity of disease, and impairment in socioprofessional functioning. Patients were prospectively randomized to undergo bilateral subthalamic nucleus stimulation (n = 10) or receive optimized medical treatment (n = 10). Parkinsonian motor scores, quality of life, cognition, and psychiatric morbidity were assessed at inclusion and at 6, 12, and 18 months after randomization. RESULTS: Quality of life was improved by 24% in surgical and 0% in nonsurgical patients (p < 0.05). After 18 months, the severity of parkinsonian motor signs "off" medication, levodopa-induced motor complications, and daily levodopa dose were reduced by 69%, 83%, and 57% in operated patients and increased by 29%, 15%, and 12% in the group with medical treatment only (p < 0.001). Adverse events were mild or transient, and overall psychiatric morbidity and anxiety improved in the surgical group. CONCLUSIONS: Subthalamic nucleus stimulation should be considered a therapeutic option early in the course of Parkinson disease.

Activities of Daily Living↗
PubMed2006

A simplified approach to improve the efficiency and safety of ex vivo hematopoietic gene therapy in fanconi anemia patients.

Fanconi anemia (FA) is an inherited DNA repair disorder characterized by genetic instability of cells lacking a functional FA/BRCA pathway. Previous studies have shown that in vitro stimulation of bone marrow cells (BMCs) from FA mice promotes apoptosis, reduces the reconstitution ability of the stem cells, and induces myelodysplasia and myeloid leukemia upon reinfusion of the cells. This suggests the convenience of adapting standard protocols of gene therapy to FA. Here we show that the reserve of BM progenitors in FA patients is generally below 20% of normal values. Because this reduced reserve could activate the cycling of BM progenitors, we developed a simplified protocol to transduce BMCs from FA patients with gammaretroviral vectors. We demonstrate that a short in vitro manipulation (12-24 hr) of fresh mononuclear BMCs is sufficient to transduce 42% of hematopoietic progenitors from FA-A patients, in the absence of in vitro prestimulation. When FANCA-expressing vectors were used, this simple procedure reversed the phenotype of the BM progenitors from these patients. We propose that our approach will be more efficient and safer compared with standard gene therapy protocols for FA.

Bone Marrow Cells↗
PubMed2006

Association of increased fibrinogen concentration with impaired activation of anticoagulant protein C.

BACKGROUND: Low levels of activated protein C (APC) are a risk factor for venous thrombosis. The mechanisms leading to interindividual differences in APC are not totally elucidated. Protein C is activated by the thrombin-thrombomodulin complex. As thrombin binds to fibrinogen and thrombomodulin through a common region, it is conceivable that fibrinogen influences the activation of protein C. This would help to explain the association between high levels of fibrinogen and an increased thrombotic risk. METHODS: We analyzed the association between circulating APC levels and fibrinogen concentration in 382 healthy subjects. Subsequently, we studied the effect of increasing fibrinogen concentrations on the APC generation on cultured endothelial cells. RESULTS: An independent inverse association between circulating APC levels and fibrinogen was found [betacoefficient, -0.16; 95% confidence interval (95% CI) -0.26, -0.06; P = 0.001]. For each 100 mg dL(-1) increase in fibrinogen, the independent risk of having low APC levels (<0.7 ng mL(-1)) was almost three times higher (OR 2.8; 95% CI 1.1, 7.2; P = 0.04). Accordingly, a notable association between increasing fibrinogen concentrations and the reduction in the thrombin-thrombomodulin dependent activation of protein C on endothelial cells was found (r = -0.57; P = 0.002). CONCLUSIONS: We present evidence of an inverse association between circulating APC and fibrinogen levels. According to this finding together with the results of our in vitro experiments, we propose that the impairment in the generation of APC on endothelial cells constitutes a new prothrombotic mechanism of fibrinogen.

Adult↗
PubMed2006

Circulating activated protein C is reduced in young survivors of myocardial infarction and inversely correlates with the severity of coronary lesions.

BACKGROUND: Cardiovascular risk factors for myocardial infarction (MI) are less frequent in younger than in older MI survivors. Therefore, the thrombotic component of MI may play a more important role at a young age. As activated protein C (APC) provides systemic anticoagulant and anti-inflammatory protection, a low plasma APC level may be an arterial thrombotic risk factor. AIM: To determine whether there is an association between reduced APC levels and early MI and severe coronary lesions. METHODS: APC was measured in 231 young MI survivors and 231 controls. RESULTS: Low APC levels were significantly associated with MI. Compared with the fourth quartile, the odds ratio (OR) for APC values in the first quartile was 3.7 [95% confidence interval (CI) = 2.1-6.4], and 3.2 (1.5-7.0) after adjustment for cardiovascular risk factors. Moreover, each decrease of 0.43 ng mL(-1) (1 SD) in APC increased the OR 1.7 times (1.4-2.2), and 1.5 times (1.2-1.9) after adjustment for cardiovascular risk factors. Low APC levels were also associated with the number of coronary arteries affected and with the severity of coronary lesions (P < 0.001). CONCLUSIONS: There is a significant association between low circulating APC levels and both early MI and the extent and severity of coronary atherosclerosis, which might be related to the anticoagulant and anti-inflammatory properties of APC.

Adult↗
PubMed2005

Parkinson disease, brain volumes, and subthalamic nucleus stimulation.

BACKGROUND: High-frequency stimulation of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson disease (PD). The clinical and preoperative predictive factors of the best postoperative outcome have been identified. Radiologic predictive factors were investigated. METHODS: Forty patients with PD underwent surgery for bilateral STN stimulation. MRI was performed in stereotactic conditions before surgery. Brain parenchyma, caudate nucleus, putamen, pallidum, and red nucleus volumes and the surface of the mesencephalon were measured and normalized as percentages of the intracranial volume. Clinical evaluation was performed 1 month before and 6 months after surgery. RESULTS: The normalized brain parenchyma volume was lower in patients who were older and had a longer disease duration or a lower frontal score and was not predictive of the postoperative outcome. The residual scores for activities of daily living and parkinsonian motor disability were higher in patients with a smaller normalized mesencephalon. The normalized caudate nucleus volume was predictive of the pre- and postoperative levodopa-equivalent dosage. CONCLUSIONS: Brain atrophy is not an exclusion criterion for neurosurgery, indicating that patients' neurologic, psychiatric, and neuropsychological characteristics are the best predictive factors for neurosurgery. The fact that a smaller normalized mesencephalon surface was associated with a lower beneficial effect of the subthalamic nucleus stimulation on the parkinsonian motor disability suggests that the normalized mesencephalon surface is a predictive factor of the postoperative outcome.

Activities of Daily Living↗
PubMed2005

Antibodies to carbonic anhydrase and IgG4 levels in idiopathic chronic pancreatitis: relevance for diagnosis of autoimmune pancreatitis.

BACKGROUND: Increased serum antibodies against carbonic anhydrase II (CA-II Ab) or IgG4 levels have been reported in cases of autoimmune chronic pancreatitis (ACP). AIM: To assess the relevance of serum CA-II Ab and IgG4 levels for the diagnosis of ACP in idiopathic CP (ICP) versus alcoholic CP and Sjogren's syndrome (SS). SUBJECTS: This was a multicentre study involving 227 subjects divided into four groups: ICP (n = 54), normal controls (n = 54, paired by age and sex with ICP patients), alcoholic CP (n = 86), and SS (n = 33). METHODS: CA-II Ab was measured by ELISA and confirmed by western blotting. A score of easy clinical use with major clinical, morphological, and biochemical parameters for the diagnosis of ACP was applied. RESULTS: The percentage of patients with increased serum CA-II Ab was higher in the ICP group (28%) than in controls (1.9%) and in patients with alcoholic CP (10.5%), but lower than in patients with SS (64%). The proportion with elevated IgG4 levels was higher in the ICP group (15%) compared with controls (1.9%) and SS (0%) but not significantly different from alcoholic CP (8%). Most ICP patients (7/8) with high IgG4 levels exhibited increased CA-II Ab and a compatible ACP score. A definitive diagnosis of ACP by histological analysis was associated with other autoimmune disorders, an increase in both serum IgG4 and CA-II Ab levels, and IgG4 positive plasma cells. CONCLUSIONS: The increase in serum IgG4 levels was strongly associated with elevated CA-II Ab levels, manifestations compatible with ACP, and lymphoplasmacytic infiltration when surgical specimens were available.

Adolescent↗
PubMed2005

Tourette's syndrome and deep brain stimulation.

In this prospective double blind randomised "N of 1" study, a patient with a severe form of Tourette's syndrome was treated with bilateral high frequency stimulation of the centromedian-parafascicular complex (Ce-Pf) of the thalamus, the internal part of the globus pallidus (GPi), or both. Stimulation of either target improved tic severity by 70%, markedly ameliorated coprolalia, and eliminated self injuries. Severe forms of Tourette's syndrome may benefit from stimulation of neuronal circuits within the basal ganglia, thus confirming the role of the dysfunction of limbic striato-pallido-thalamo-cortical systems in this disorder.

Adult↗
PubMed2005

Stimulation of the subthalamic nucleus in Parkinson's disease: a 5 year follow up.

BACKGROUND: The short term benefits of bilateral stimulation of the subthalamic nucleus (STN) in patients with advanced levodopa responsive Parkinson's disease (PD) are well documented, but long term benefits are still uncertain. OBJECTIVES: This study provides a 5 year follow up of PD patients treated with stimulation of the STN. METHODS: Thirty seven consecutive patients with PD treated with bilateral STN stimulation were assessed prospectively 6, 24, and 60 months after neurosurgery. Parkinsonian motor disability was evaluated with and without levodopa treatment, with and without bilateral STN stimulation. Neuropsychological and mood assessments included the Mattis Dementia Rating Scale, the frontal score, and the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: No severe peri- or immediate postoperative side effects were observed. Six patients died and one was lost to follow up. Five years after neurosurgery: (i) activity of daily living (Unified Parkinson Disease Rating Scale (UPDRS) II) was improved by stimulation of the STN by 40% ("off" drug) and 60% ("on" drug); (ii) parkinsonian motor disability (UPDRS III) was improved by 54% ("off" drug) and 73% ("on" drug); (iii) the severity of levodopa related motor complications was decreased by 67% and the levodopa daily doses were reduced by 58%. The MADRS was unchanged, but cognitive performance declined significantly. Persisting adverse effects included eyelid opening apraxia, weight gain, addiction to levodopa treatment, hypomania and disinhibition, depression, dysarthria, dyskinesias, and apathy. CONCLUSIONS: Despite moderate motor and cognitive decline, probably due to disease progression, the marked improvement in motor function observed postoperatively was sustained 5 years after neurosurgery.

Activities of Daily Living↗
PubMed2005

[Helicobacter pylori and gastric cancer: relationship with histological subtype and tumor location].

INTRODUCTION: Helicobacter pylori (HP) has been implicated in the pathogenesis of gastric adenocarcinoma. Published data on HP infection and its association with both histological subtype and tumor localization are contradictory and few data are available on this topic in Spain. The aim of the present study was to evaluate the association of HP infection with histological subtype and tumor localization in a series of patients with gastric adenocarcinoma. MATERIAL AND METHOD: We retrospectively reviewed all the patients diagnosed with gastric neoplasms in Hospital del Mar in Barcelona between 1995 and 2001. The histological subtype was established using Lauren's classification. Tissue samples were obtained from the surgical specimen or from endoscopic biopsies. HP infection was histologically determined through hematoxylin-eosin, Masson's trichromic, and Giemsa staining. RESULTS: During the study period, 304 gastric neoplasms, 275 (90.4%) adenocarcinomas, 22 (7.2%) lymphomas, 3 (1.0%) leiomyosarcomas, 2 (0.7%) degenerated gastrointestinal stromal tumors (GIST) and 2 (0.7%) Kaposi's sarcomas were diagnosed. In patients with adenocarcinoma, the mean age at diagnosis was 69 years and most patients were male (62%). A total of 48.1% of the neoplasms were located in the gastric antrum, 23.7% in the body and 19.1% in the fundus (13.6% in the period 1994-1997 and 25.4% in the period 1998-2001, p = 0.018). Intestinal-type gastric carcinoma was observed in 56% of the patients, diffuse-type in 28% and indeterminate-type in 16%. HP infection was confirmed in 69% of the patients (68% in intestinal subtype, 69% in diffuse subtype, and 69% in indeterminate subtype, p = 0.84), and was significantly associated with distal adenocarcinomas vs. proximal adenocarcinomas (73.6% vs 48.6%, p < 0.05). CONCLUSIONS: No differences were observed between the histological type of adenocarcinoma and HP infection. In the last few years, the incidence of fundic adenocarcinomas has increased. These tumors show a lower association with HP infection.

Adenocarcinoma↗
PubMed2005

The multifunctional protein C system.

The protein C pathway is a major regulator of blood coagulation, since it controls the conversion of prothrombin to thrombin through a feedback inhibition mechanism. Protein C circulates in plasma as an inactive zymogen and is activated on the surface of endothelial cells by the thrombin-thrombomodulin complex, a process that can be further enhanced when protein C binds to its membrane receptor, the endothelial-cell protein C receptor. Activated protein C (APC) is then released from the complex, binds protein S and inhibits thrombin formation by inactivating coagulation factors Va and VIIIa. The importance of the protein C anticoagulant pathway is emphasized by the increased risk of venous thromboembolism (VTE) associated with protein C and protein S deficiencies, the factor V Leiden mutation, and reduced circulating APC levels. The protein C pathway also plays a significant role in inflammatory processes, since it prevents the lethal effects of E. coli-associated sepsis in animal models and improves the outcome of patients with severe sepsis. APC seems to display anti-apoptotic and neuroprotective activities. Thus, it reduces organ damage in animal models of sepsis, ischemic injury, endothelial cell injury, or stroke. Further research will hopefully widen the current therapeutic perspectives in all these illnesses, where these effects might play a crucial role in their treatment. This review will summarize the mechanisms that contribute to these biological activities of the protein C pathway.

Animals↗
PubMed2005

Role of Helicobacter pylori in stomach cancer after partial gastrectomy for benign ulcer disease.

OBJECTIVE: To determine the prevalence of Helicobacter pylori infection in patients having undergone gastrectomy for non-neoplastic disease who later developed gastric stump cancer. MATERIAL AND METHODS: Retrospective study of all patients with partial gastrectomy for non-malignant peptic disease who were submitted to an endoscopic exploration between 1995 and 2001. A comparison was made of major clinical and histological characteristics, and the presence of Helicobacter pylori among patients with and without gastric cancer in the stomach remnant. RESULTS: A total of 73 patients were studied in this period. Fifteen patients (20.5%) had remnant-stump gastric cancer. All but one were adenocarcinomas (71% intestinal and 29% diffuse, respectively). The average time between diagnosis of gastric cancer and previous gastrectomy was 32 (14-48) years. There was a higher detection rate of Helicobacter pylori in patients with cancer in the gastric remnant (100 vs. 81.5%, respectively, p < 0.07). No relationship was seen between type of gastric reconstruction (Billroth I or II) and rate of Helicobacter pylori detection. CONCLUSIONS: Helicobacter pylori infection is frequent in patients with previous gastrectomy for non-neoplastic disease. The results of the study suggest that Helicobacter pylori infection may play a role in gastric stump cancer.

Adenocarcinoma↗
PubMed2004

Small-cell carcinoma of the urinary bladder. A clinico-pathological study of ten cases.

Small-cell carcinoma (SCC) of the urinary bladder is an infrequent neoplasia accounting for 0.5% of all tumors located at this level. There is a predilection for males over females with a 4:1 proportion and a median age of 66 years. In most cases, the initial diagnosis is made at the metastatic or progressive stage of the disease. For this study, we collected ten cases of SCC of the urinary bladder, diagnosed over a period of 16 years, to describe the morphological and immunocytochemical characteristics of these infrequent neoplasia. In all cases, clinical data such as age at presentation, personal background, clinical symptoms, stage, treatment, clinical outcome and present status were available. Primary antibodies included chromogranin, neuron-specific enolase, synaptophysin, PGP 9.5, HNK-1, cytokeratin 34betaE12, cytokeratin 20, thyroid transcription factor-1 (TTF-1), c-erbB2 (CB-11), p53 (DO7), and Ki67 (MIB-1). In addition to the expression of neural/neuroendocrine markers, immunostaining for p53 and c-erbB2 was found in 80% and 50% of cases, respectively. In this paper, we confirm the aggressive course of the neoplastic disease. The expression of c-erbB2 in 50% of cases opens up hypothetical new possibilities for the use of immunotherapy in such cases.

Aged↗
PubMed2004

[Hospital registry of pancreatic tumors. Experience of the Hospital Clínic in Barcelona (Spain)].

OBJECTIVE: To describe the characteristics of patients included in the pancreatic tumor registry of the Hospital Clínic of Barcelona. PATIENTS AND METHOD: All patients with pancreatic tumors attended between July 1990 and March 2003 were registered. Data collection included: age, gender, date of diagnosis, diagnosis, histology, size, location and tumor stage, and treatment. The correlation between tumor stage and age, date of diagnosis, and tumor location was also evaluated. RESULTS: Six hundred thirty patients with pancreatic tumors were included, representing an incidence of 60 patients/year. The mean age was 66 years and the male-to-female ratio was 1,18:1. The most frequent lesion was malignant tumor of the pancreas (92%), and the most frequent histological type was pancreatic ductal adenocarcinoma (73%). The most frequent location was the head of the pancreas (64%). In 28% of the patients, pancreatic cancer was diagnosed in stage I and II. Resection was performed in 31% of patients, whereas 48% of the patients received no treatment. The ratio between local (stage I)/disseminated (stage IV) disease was 0,34. The ratio between stage I/IV increased with age, diagnosis prior to 1994, and tumor location in the head of the pancreas. CONCLUSION: Hospital tumor registries can be used to define the profile of the attended population, which can help to delineate the best diagnostic-therapeutic strategy and can be useful in clinical research.

Adult↗
PubMed2004

Neuroectodermal immunophenotype in uterine malignant mullerian tumors (MMT): comparative immunohistochemical analysis with embryonal uterine development.

Multidirectional differentiation of neoplastic cells in uterine MMT is still a subject of controversy. The present study was designed to assess the immunophenotype of 15 uterine MMT paying special attention to the markers of neural (neuroendocrine) differentiation. In addition, the same immunohistochemical study was performed on 20 human fetal specimens in order to establish possible relationships between the immunophenotype of MMT and the expression of the corresponding antigens in the fetal tissues of the embryonal female genital tract. Besides the typical immunohistochemical patterns in three cases the epithelial component showed simultaneous coexpression of vimentin and desmin. EMA and cytokeratin, whereas epithelial markers were coexpressed with vimentin in the sarcomatous component of one adenosarcoma. Moreover, both components were immunoreactive to the markers of neural differentiation (PGP 9.5, GFAP, HNK-1, N-CAM, HBA71). This aberrant expression was not correlated with morphological signs of neural differentiation at either light microscopy or ultrastructural levels. Regarding the analysis of fetal tissues, both epithelial and mesenchymal elements in the fetal genital tract expressed the above-mentioned neural markers at different dates of gestation. The intensity of this expression diminishes as the fetus matures and at the end of antenatal life the immunophenotype characteristic for adult life is established. Taking into consideration the capacity of uterine tissue to reproduce embryonal phenotype during neoplastic transformation, we studied this abnormal immunoprofile and its hypothetic value for the diagnosis and prognosis of MMT.

Aged↗
PubMed2003

Quality assessment of genetic markers used for therapy stratification.

PURPOSE: Therapy stratification based on genetic markers is becoming increasingly important, which makes commitment to the highest possible reliability of the involved markers mandatory. In neuroblastic tumors, amplification of the MYCN gene is an unequivocal marker that indicates aggressive tumor behavior and is consequently used for therapy stratification. To guarantee reliable and standardized quality of genetic features, a quality-assessment study was initiated by the European Neuroblastoma Quality Assessment (ENQUA; connected to International Society of Pediatric Oncology) Group. MATERIALS AND METHODS: One hundred thirty-seven coded specimens from 17 tumors were analyzed in 11 European national/regional reference laboratories using molecular techniques, in situ hybridization, and flow and image cytometry. Tumor samples with divergent results were re-evaluated. RESULTS: Three hundred fifty-two investigations were performed, which resulted in 23 divergent findings, 17 of which were judged as errors after re-evaluation. MYCN analyses determined by Southern blot and in situ hybridization led to 3.7% and 4% of errors, respectively. Tumor cell content was not indicated in 32% of the samples, and 11% of seemingly correct MYCN results were based on the investigation of normal cells (eg, Schwann cells). Thirty-eight investigations were considered nonassessable. CONCLUSION: This study demonstrated the importance of revealing the difficulties and limitations for each technique and problems in interpreting results, which are crucial for therapeutic decisions. Moreover, it led to the formulation of guidelines that are applicable to all kinds of tumors and that contain the standardization of techniques, including the exact determination of the tumor cell content. Finally, the group has developed a common terminology for molecular-genetic results.

Biomarkers, Tumor↗
PubMed2003

Clinical usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by means of endosonography-guided fine-needle aspiration biopsy.

AIM: To establish the usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by comparing this technique with conventional cytology in aspirates obtained by endosonography-guided fine-needle aspiration. METHODS: All consecutive patients with pancreatic focal lesions undergoing endosonography-guided fine-needle aspiration were included. Samples were obtained with the concurrence of an attendant cytopathologist. Detection of codon-12 KRAS mutations was performed by the restriction fragment length polymorphism-polymerase chain reaction method. The effectiveness of conventional cytology, KRAS mutational analysis and their combination was established with respect to the definitive diagnosis. A cost-effectiveness analysis was also performed. RESULTS: Thirty-three patients had pancreatic adenocarcinoma and 24 patients had other lesions. A total of 136 samples was obtained. In patients in whom specimens were adequate (93% for cytology; 100% for mutational analysis), the specificity of both techniques was 100%, whereas the sensitivity favoured cytology (97% vs. 73%). When inadequate samples were considered as misdiagnosed, a combination of both techniques reached the highest overall accuracy (cytology, 91%; mutational analysis, 84%; combination of both, 98%). CONCLUSIONS: Cytology from aspirates obtained by endosonography-guided fine-needle aspiration is the most precise single technique for the diagnosis of pancreatic adenocarcinoma. However, when adequate specimens are not available to reach a cytological diagnosis, the addition of KRAS mutational analysis represents the best strategy.

Adenocarcinoma↗