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J Pujol

Publications and source records attributed to J Pujol.

At least 37 records · Page 2Linked to original sources
PubMed2000

3-D AE visualization of bone-cement fatigue locations.

This study addresses the visualization of crack locations in bone-cement material using a three-dimensional acoustic emission source location technique. Computer software based on an earthquake location technique was developed to determine AE source locations and was used to investigate material cracks formed at the tip of a notch in bone cement. The computed locations show that the cracks form linear features with dimensions between 0.1 and 0.2 mm although larger linear features (almost 3.5 mm) also are present. There is a difference of about 2.5 mm between the average of the event locations, and the location of the tip of the notch is 2.5 mm, which may be due to the finite size of the sensors (5 mm in diameter).

Animals↗
PubMed2000

Brain cortical activation during guitar-induced hand dystonia studied by functional MRI.

Focal hand dystonia in musicians is a strongly task-related movement disorder. Typically, symptoms become apparent only when players execute specific overpracticed skilled exercises on their instrument. We therefore examined five guitarists with functional MRI during dystonic symptom provocation by means of an adapted guitar inside the magnet. The activation patterns obtained in comparable nondystonic guitarists and in the study patients when performing normal-hand exercise served as references. A 1.5-T system equipped with echo-speed gradients and single-shot echoplanar imaging software was used. Data acquisition was centered on the cortical motor system encompassed in eight contiguous slices. Dystonic musicians compared with both control situations showed a significantly larger activation of the contralateral primary sensorimotor cortex that contrasted with a conspicuous bilateral underactivation of premotor areas. Our results coincide with studies of other dystonia types in that they show an abnormal recruitment of cortical areas involved in the control of voluntary movement. However, they do suggest that the primary sensorimotor cortex, rather than being underactive in idiopathic dystonic patients, may be overactive when tested during full expression of the task-induced movement disorder.

Adult↗
PubMed2000

Diagnosis and management of diffuse leiomyomatosis of the oesophagus.

Diffuse leiomyomatosis of the oesophagus is a rare entity among oesophageal diseases. Histopathologically it is characterized by diffuse hypertrophy of the muscular layer extending to the whole oesophagus predominantly in the lower third, where it can result in tumour formation. Leiomyomatosis can involve the upper part of the stomach and is frequently associated with genital or tracheobronchial (bronchitracheal) muscular localizations. Also, it can be associated with Alport's syndrome in familial cases. For diagnosis, barium swallow, computerized tomography (CT) scan and, in recent years, endoscopic ultrasonography are used. Oesophageal resection is the only suitable treatment in symptomatic cases. We report three observations during 1979-95.

Adult↗
PubMed2000

Tissue distribution, autoradiography, and metabolism of 4-(2'-methoxyphenyl)-1-[2' -[N-2"-pyridinyl)-p-[(18)F]fluorobenzamido]ethyl]piperazine (p-[(18)F]MPPF), a new serotonin 5-HT(1A) antagonist for positron emission tomography: An In vivo study in rats.

The in vivo behavior of 4-(2'-methoxyphenyl)-1-[2'-[N-(2"-pyridinyl)-p-[(18)F]fluorobenzamido ]ethyl]-piperazine (p-[(18)F]MPPF), a new serotonin 5-HT(1A) antagonist, was studied in awake, freely moving rats. Biodistribution studies showed that the carbon-fluorine bond was stable in vivo, that this compound was able to cross the blood-brain barrier, and that a general diffusion equilibrium could account for the availability of the tracer. The great quantity of highly polar metabolites found in plasma did not contribute to the small amounts of metabolites found in hippocampus, frontal cortex, and cerebellum. Exvivo p-[(18)F]MPPF and in vitro 8-hydroxy-2-(di-n-[(3)H]propylamino)tetralin autoradiography were compared both qualitatively and quantitatively. Qualitative evaluation proved that the same brain regions were labeled and that the p-[(18)F]MPPF labeling is (a) in total agreement with the known distribution of 5-HT(1A) receptors in rats and (b) characterized by very low nonspecific binding. Quantitative comparison demonstrated that the in vivo labeling pattern obtained with p-[(18)F]MPPF cannot be explained by differences in regional blood flow, capillary density, or permeability. The 5-HT(1A) specificity of p-[(18)F]MPPF and binding reversibility were confirmed in vivo with displacement experiments. Thus, this compound can be used to evaluate parameters characterizing 5-HT(1A) binding sites in the brain.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Relationship between cerebral perfusion in frontal-limbic-basal ganglia circuits and neuropsychologic impairment in patients with subclinical hepatic encephalopathy.

UNLABELLED: Early detection of neuropsychologic impairment in cirrhotic patients with subclinical hepatic encephalopathy (SHE) is important for their prognosis and quality of life. Abnormal MRI and MR spectroscopy (MRS) findings have been proposed as early markers of brain damage in these patients, but the role of functional neuroimaging in this field still has to be defined. In this study, the SPECT perfusion pattern in patients with SHE was investigated, and the relationship between regional cerebral blood flow (rCBF) and the MRI, MRS, neuropsychologic evaluation and biochemical data of these patients was assessed. METHODS: Data were obtained from 13 cirrhotic patients with SHE and 13 age-matched healthy volunteers. Fasting venous blood ammonia and manganese sampling and a battery of standardized neuropsychologic tests related to basal ganglia function and sensitive to the effects of liver disease were all performed on the same day. MRI and 99mTc-hexamethyl propyleneamine oxime SPECT were performed within 2 wk. RESULTS: A pattern of decreased prefrontal rCBF was found in patients with SHE compared with healthy volunteers. Basal ganglia and mesial temporal rCBF correlated inversely with performance on motor tasks involving speed (Purdue pegboard test) and frontal premotor function (Luria graphic alternances and Stroop tests). Thalamic rCBF correlated positively with T1-weighted MRI signal hyperintensity in the globus pallidus and with abnormal MRS findings. Neither the MRI signal intensity of the globus pallidus nor MRS correlated with neuropsychologic test results. CONCLUSION: Cirrhotic patients with SHE show a SPECT pattern of impaired prefrontal perfusion that does not seem to account for their neuropsychologic deficits. On the other hand, perfusion in some parts of the limbic system and limbic-connected brain regions, such as the striatum and the mesial temporal regions, increased with neuropsychologic impairment. These findings suggest that brain SPECT may be more sensitive than MRI in delineating cirrhotic patients requiring in-depth clinical testing to reveal basal ganglia-related neuropsychologic alterations.

Basal Ganglia↗
PubMed2000

[Developmental tendencies of the sagittal tooth axis between 10-13 years of age and the end of life; impact on retention?].

In this study, 854 lateral cephalograms of normal toothed subjects from 10 to 87 years old who had no orthodontic treatment are analyzed. The posterior angles established by molars and sagitally examined maxillo-mandibular incisor-canine groups during occlusion are measured with age. These modifications are quantified in a general manner and then depending on facial typology.

Adolescent↗
PubMed2000

[Laparoscopic treatment of colorectal polyps].

UNLABELLED: Endoscopic removal is the treatment of choice for colorectal polyps. However, this therapeutic option is limited by the size of the tumor, sessile implantation, or technical impossibility. These cases are ideal for laparoscopic treatment because of the anatomy of the colon is and because the risk of manipulating a malignant lesion is lower. However, there is the added difficulty of identifying the lesion. In other cases, unsuspected neoplastic invasion of an endoscopically removed polyp makes surgery necessary. AIM: To evaluate the results of laparoscopic surgery in the treatment of colorectal polyps. MATERIAL AND METHODS: Between December 1997 and November 1999, 270 endoscopic polypectomies were performed. In 15 patients, endoscopic removal was technically impossible or contraindicated. These patients were treated laparoscopically. One patient who was found to have an invasive carcinoma following polypectomy was also treated laparoscopically. The technical characteristics of the operation (duration, conversion, morbi-mortality, postoperative stay, size of the polyp and number of ganglions) were analyzed and compared with 43 other laparoscopic operations in the colon carried out for other reasons (n = 43). RESULTS: In nine patients, surgery was indicated because of the size of the polyp, in three for technical reasons, in three for severe atypia and in one because of an invasive carcinoma following polypectomy. The operation was completed by laparoscopy in 15 patients (94%). Ten right hemicolectomies, five sigmoidectomies and one anterior resection assisted by hand port were carried out. The diameter of the lesions was 4.4 +/- 2.4 cm. Histological studies revealed carcinoma in situ in five, infiltrating carcinoma in two, non-malignant adenoma in six and lipoma in one. Comparison of the results of patients who underwent colectomy for polyps with those of the group who underwent surgery for other reasons revealed lower morbidity (24% vs. 22%) and need for conversion (7% vs. 16%), as well as a significant decrease in operating time (130 +/- 10 vs. 148 +/- 32 min, p < 0.05) and in postoperative stay (6.6 +/- 1.4 vs. 8.3 +/- 2.5 days, p < 0.02). CONCLUSION: Laparoscopic colonic resection is particularly suitable in the treatment of colorectal polyps.

Adult↗
PubMed1999

Functional magnetic resonance imaging study of frontal lobe activation during word generation in obsessive-compulsive disorder.

BACKGROUND: Functional imaging studies have demonstrated abnormal patterns of brain activity in obsessive-compulsive disorder, which consistently suggest the alteration of frontal lobe functioning. We performed a brain activation study in obsessive-compulsive disorder using a cognitive task involving the frontal lobes. METHODS: Twenty patients and 20 healthy control subjects were assessed with functional magnetic resonance imaging during a phonologically guided word generation task. The study analysis was based on the comparison of group average time-course functional changes occurring at the site of largest frontal cortex activation during alternating rest and task periods. RESULTS: In terms of relative signal changes, patients showed a significantly greater activation during word generation and a defective suppression of this activation during the following rest period. Both abnormal imaging findings significantly correlated with the severity of the clinical process assessed by the Yale-Brown Obsessive-Compulsive Scale. CONCLUSIONS: The results indicate that functional magnetic resonance imaging during cognitive challenge may be useful to reveal distinctive features of latent brain dysfunction in obsessive-compulsive disorder.

Adolescent↗
PubMed1999

Cerebral lateralization of language in normal left-handed people studied by functional MRI.

OBJECTIVE: To use functional MRI (fMRI) to further define the occurrence of left-hemisphere, bilateral, and right-hemisphere language in a normal left-handed population. METHODS: A total of 100 healthy volunteers, consisting of 50 left-handed subjects and a reference group of 50 right-handed subjects, were studied by fMRI of the frontal cortex during silent word generation. RESULTS: Ninety-six percent of right-handed subjects showed fMRI changes lateralized to the left hemisphere, whereas 4% showed a bilateral activation pattern. In contrast, left-hemisphere lateralization occurred in 76% of left-handers, bilateral activation in 14%, and right-hemisphere lateralization in the remaining 10%. The predominance of right-hemisphere activation, however, was weak in these cases; only a single left-handed subject (2%) showed complete right-hemisphere lateralization. CONCLUSIONS: Silent word generation lateralizes to the left cerebral hemisphere in both handedness groups, but right-hemisphere participation is frequent in normal left-handed subjects. Exclusive right-hemisphere activation rarely occurred in the frontal lobe region studied.

Adult↗
PubMed1999

Laparoscopic adrenalectomy. A review of 30 initial cases.

BACKGROUND: Laparoscopic adrenalectomy is a good option for removal of the adrenal gland that is becoming preferred over the conventional open technique. METHODS: We reviewed the initial 30 laparoscopic adrenalectomies (in 27 patients) that were performed at our institution from 1995 to 1998. We used the lateral decubitus transperitoneal approach in 26 cases and the retroperitoneal approach in only one case. The indications for adrenalectomy were Conn's adenoma in eight patients, pheochromocytoma in six, Cushing's syndrome in five, nonfunctional adenomas in seven, and metastasis in one case. RESULTS: Only two patients (7%) were converted to laparotomy. Operating time ranged from 75 to 240 min. Average adrenal gland size was 6.1 cm (range, 4-9 cm). There was no mortality, and morbidity occurred in only two patients (8%)-one case of self-limited gastrointestinal bleeding and one case of hypercapnia and subcutaneous emphysema (in the only patient operated by the retroperitonal approach). Mean hospital stay was 3 days (range, 1-6). CONCLUSIONS: Laparoscopic adrenalectomy is a safe and useful procedure for nearly all adrenal pathologies. Lateral decubitus transperitoneal approach is the procedure of choice in most cases.

Adenoma↗
PubMed1999

Absence of thallium-201 brain uptake in progressive multifocal leukoencephalopathy in AIDS patients.

OBJECTIVE: To evaluate the presence of thallium-201 brain uptake determined by thallium-201 brain SPECT (Tl-201 SPECT) in patients with progressive multifocal leukoencephalopathy (PML) and AIDS. MATERIAL AND METHODS: Six AIDS patients with stereotactic biopsy diagnosis of PML were prospectively evaluated with Tl-201 SPECT, Magnetic Resonance Imaging (MRI), and proton magnetic resonance spectroscopy (1H-MRS). Tl-201 SPECT results were compared with 2 patients with AIDS and biopsy proven primary CNS lymphoma. RESULTS: In all patients with PML, Tl-201 SPECT studies showed lack of uptake while MRI demonstrated subcortical white matter focal brain lesions and 1H-MRS disclosed metabolic abnormalities. Intense thallium uptake (uptake ratios of 3.2 and 5.6) was demonstrated in the 2 patients with primary CNS lymphoma. CONCLUSIONS: The present study shows that PML lesions are not detectable on Tl-201 SPECT while MRI and 1H-MRS demonstrate abnormalities, and intense thallium-201 uptake may be detected in primary CNS lymphoma. These results suggest that Tl-201 SPECT is a method which, combined with other non-invasive techniques such as MRI and 1H-MRS, may help in the diagnostic approach of PML and to differentiate PML from other high proliferative brain lesions characterized by positive thallium uptake.

AIDS Dementia Complex↗
PubMed1999

Proton magnetic resonance spectroscopy pattern of progressive multifocal leukoencephalopathy in AIDS.

The objective was to determine whether the use of intermediate echo times (135 ms) in proton magnetic resonance spectroscopy (1H-MRS) detects a homogenous pattern in progressive multifocal leukoencephalopathy (PML) in HIV-1 infected people, and to confirm the results of previous studies. Six patients infected with HIV-1, with PML established by biopsy, and six healthy age and sex matched volunteers were evaluated to define their spectroscopic pattern. 1H-MRS spectra performed at 1.5 T were obtained with the STEAM sequence: TE/TM/TR, 20 ms/13.7 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (STEAM-20) and with the PRESS sequence; TE/TR, 135 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (PRESS-135). A single voxel was placed on the lesions and on the parieto-occipital white matter of controls. The peaks of N-acetylaspartate (NAA), choline (Cho), myoinositol (mI), lactate, and lipids were considered, and the results were expressed using creatine as reference. Spectra of PML lesions were characterised by significantly reduced NAA, lactate presence, and by significantly increased Cho and lipids compared with control group values. These results indicate that 1H-MRS detects a homogenous pattern in PML lesions. Recent studies, together with this, suggest that 1H-MRS may help in the diagnostic approach to patients with suspected PML lesions associated with AIDS.

AIDS Dementia Complex↗
PubMed1998

The effect of repetitive magnetic stimulation on localized musculoskeletal pain.

Current magnetic coil stimulators can efficiently activate neural structures without deep electrode placement and the local discomfort associated with transcutaneous electrical stimulation used in pain control. We tested the possibility of reducing pain in patients with localized musculoskeletal processes by applying repetitive magnetic stimulation on the tender body region. Thirty patients were randomized to receive 40 min of real or sham magnetic stimulation. After a single session, real magnetic stimulation significantly exceeded the sham effect: a 101-point pain score decreased by 59% in the treated group and 14% in sham-treated patients (z = -3.26, p = 0.001). The pain relief attained regularly persisted for several days. Results indicate that powerful magnetic coil stimulation can efficiently reduce pain originating from localized musculoskeletal injuries.

Adult↗