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Biomedical subjects

J M Mercader

Publications and source records attributed to J M Mercader.

47 records · Page 3Linked to original sources
PubMed1976

The tolosa-hunt syndrome: report of two cases.

The Tolosa-Hunt Syndrome consists of intermittent painful ophthalmoplegia resulting from a non-specific inflammatory process in the cavernous sinus and superior orbital fissure, which responds to steroid therapy. We report two additional cases to the literature of the Tolosa-Hunt Syndrome and we are interested in pointing out the importance of orbital venography in the diagnosis of this syndrome. Orbital venography demonstrates the partial occupation of the cavernous sinus and the lack of visualization of the 3rd segment of the superior ophthalmic vein.

Adrenal Cortex Hormones↗
PubMedDate not supplied

MRI and genetic correlates of cognitive function in elders with memory impairment.

The present study investigated the relationship between genetic variation, MRI measurements and neuropsychological function in a sample of 58 elders exhibiting memory decline. In agreement with previous reports, we found that the epsilon4 allele of the apolipoprotein E (APOE) and the D allele of the angiotensin converting enzyme (ACE) polymorphisms negatively modulated the cognitive performance. Further, we found an association between the A allele of the apolipoprotein C1 (APOC1) polymorphism and poorer memory and frontal lobe function. No clear associations emerged between MRI measures of white matter lesions (WML) or hippocampal sulcal cavities (HSC) and the cognitive performance after controlling for age effects. Further, the degree of WML or HSC lesions was in general not predisposed genetically except for the presence of the A allele of the APOC1 polymorphism that was related to a higher severity of HSC scores. Our results suggest that WML or HSC do not represent important brain correlates of genetic influences on cognitive performance in memory impaired subjects.

Aged↗
PubMedDate not supplied

[Application of magnetic resonance spectroscopy in the study of brain disease].

INTRODUCTION AND OBJECTIVE: Magnetic resonance spectroscopy (MRS) is a non-invasive technique used for the neurochemical study of the brain in vivo. The aim of this work is to review the main investigations that have focused on the study of cerebral pathology. DEVELOPMENT: Cerebral MRS studies started in 1983 but the maximum development has been in the 90's. The pathologies more investigated were Alzheimer's disease, multiple sclerosis, schizophrenia, and depression. Although several nuclei can be observed the most investigated are phosphor (P31) and hydrogen (H1). Nowadays proton MRS is the more frequently used technique. The low levels of N-acetyl-aspartate are a good indicator of neuronal loss. Their determination is complementary to the volumetric structural studies from magnetic resonance imaging. The peak of myo-inositol seems to be a neurochemical marker for the Alzheimer's disease. CONCLUSIONS: MRS have contributed to the increase of knowledge about the physiopathology of normal aging, degenerative processes, demyelinating and psychiatric diseases. Potentially can contribute to differential diagnose in Alzheimer's and Parkinson's diseases. Recently it has also been opened a new research potential in the field of the pharmacological treatment effects in discrete cerebral regions.

Aging↗
PubMedDate not supplied

[Study of the long term sequelae of traumatic brain injury: evaluation of declarative and procedural memory, and its neuroanatomic substrate].

INTRODUCTION AND OBJECTIVES: The hippocampus and the striatum have been proposed as respectively cerebral substrates of declarative and procedural memory. Both structures are vulnerable to traumatic brain injury. Although declarative and procedural memory have been reported to be impaired in traumatic brain injury (TBI), volumetric measures have so far failed to associate this impairment with atrophy of hippocampal and striatal structures. In our study, we investigated the profile of declarative and procedural memory in children who suffered from moderate to severe traumatic brain injury during childhood (injury test interval: 9.42+/-1.98 years). PATIENTS AND METHODS: Nineteen patients and matched controls were evaluated on tests of declarative memory and motor learning. Results showed that TBI subjects exhibit poorer performance in both tasks. Moreover, structural magnetic resonance images were obtained from TBI subjects. In order to relate neuropsychological performance with hippocampal and neostriatal volumetric data, correlation analyses were performed. RESULTS: Significant positive correlations were obtained between hippocampal volume and memory for objects. Striatal volume correlated positively with motor learning and with verbal memory. CONCLUSIONS: It thus seems that plasticity does not completely compensate for the memory deficits resultant from neural loss in the immature brain.

Adolescent↗
PubMedDate not supplied

Hepatoblastoma. An attempt to apply histologic classification to aspirates obtained by fine needle aspiration cytology.

We applied cytologic and architectural diagnostic criteria to the aspiration smears of six cases of hepatoblastoma (HBL) in order to establish whether it is possible to obtain a reliable cytologic diagnosis of this neoplasm and to subclassify it based on cytologic evidence alone. We describe two groups of HBL, undifferentiated and differentiated. The undifferentiated group comprises anaplastic and embryonal subtypes, and the differentiated group comprises fetal and macrotrabecular subtypes. Our findings suggest that the fetal and macrotrabecular subtypes have a rather characteristic cytologic pattern, permitting us to differentiate between the two and to distinguish them from the other two subtypes. The differential diagnosis between the anaplastic and embryonal subtypes is more complex and can be difficult to carry out using cytologic criteria exclusively. The immunophenotypic pattern reflects the degree of maturity of each subtype and helps with cytologic subclassification. The cytologic differential diagnosis of undifferentiated HBL must include hepatic metastases of small round cell tumors of childhood. The cytologic differential diagnosis between differentiated HBL and hepatocellular carcinoma may be very difficult. We suggest that the cytologic subclassification of HBL is possible with the reservation that the predominant pattern may mask other, associated patterns.

Biopsy, Needle↗
PubMedDate not supplied

MR in trichloroethane poisoning.

We present a case of acute trichloroethane intoxication caused by inhalation of typewriter correction fluid. CT and MR findings revealed lesions in the basal ganglia and cortex similar to those observed in patients with methanol and carbon monoxide poisoning.

Adolescent↗
PubMedDate not supplied

Estimation of bone marrow cellularity by means of vertebral magnetic resonance.

BACKGROUND AND OBJECTIVE: A magnetic resonance (MR) signal shows an inverse correlation with bone marrow cellularity. In this study, we investigated the possibility of estimating the degree of bone marrow cellularity by means of this non-invasive technique. METHODS: In 25 patients with different hematological disorders and homogeneous bone marrow distribution, the percentage of bone marrow cellularity was compared to the MR signal of four middorsal vertebrae in T1 sequence. As internal control, the MR signal of the mid-dorsal spinal cord region was used. The results were expressed as the MR signal ratio (great mean MR signal of four vertebrae/MR signal of the spinal cord). RESULTS: The correlation coefficient (r) between both parameters was -0.93 (p < 0.0001). All observed values fell within the 90% limits of predicted values. The mean difference between observed and predicted bone marrow cellularity was 5.6 (SD 4.0)%. INTERPRETATION AND CONCLUSIONS: The measurement of the MR signal is not easy to standardize since it depends to a large degree on the control employed. The spinal cord proved to be a satisfactory internal control of the MR signal. Within defined conditions, MR can be useful for a rough estimate of bone marrow cellularity in several clinical situations, such as analysis of tumor burden for prognosis of some leukemias and the evaluation of response to therapy in both proliferative and hypoplastic disorders.

Adolescent↗