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Biomedical subjects

P Barreiro

Publications and source records attributed to P Barreiro.

At least 19 recordsLinked to original sources
PubMed1997

Gene dosage effect in one family with myoclonic epilepsy and ragged-red fibers (MERRF).

OBJECTIVES: We analyzed the percentage of mitochondrial DNA (mtDNA) heteroplasmy in blood samples of 13 individuals belonging to a three family generation of myoclonic epilepsy with ragged-red fibers (MERRF) and compared the 5 affected patients and the 8 unaffected relatives. MATERIAL AND METHODS: DNA was extracted from blood and muscle of the proband and from blood of 12 maternal relatives. A PCR restriction analysis method was used to detect the mutation. RESULTS: The proband had the complete MERRF phenotype. The phenotype in three other individuals in the maternal lineage was consistent with the MERRF syndrome. The remaining were asymptomatic. The np 8344 mutation was observed in muscle and blood of the proband, and in blood from every one of 12 maternal relatives, ranging from 44% to 83% of mutated genomes. Symptomatic individuals had higher levels (P < 0.001) of mutated mtDNA than asymptomatic maternal relatives. However, high proportions of mutant genomes (up to 63%) were found in asymptomatic relatives. CONCLUSIONS: Although there seems to be a gene dosage effect in MERRF, we found no absolute relationship between the relative proportion of mutant genomes in blood and clinical severity. Factors other than gene dosage in blood may account for the differences in clinical phenotype.

Adult↗
PubMed1996

Cluster headache syndrome associated with middle cerebral artery arteriovenous malformation.

Cluster headache (CH) is an idiopathic cephalalgic syndrome, although several pathological processes have been described in association with this syndrome. We report two cases of cluster headache in hospitalized patients with middle cerebral artery dependent arteriovenous malformation (AVM). After surgical removal of the AVM the headache completely resolved, suggesting that complementary studies and treatment of the underlying aetiology may be indicated for secondary forms of cluster headache.

Cerebral Arteries↗
PubMed1996

[Acute cervical ischemic myelopathy: anterior spinal artery syndrome].

Acute ischemic myelopathy is an uncommon cause of spinal lesion. Its most common location is the thoracic-lumbar region in the territory of the anterior spinal artery. The involvement of the cervical segment is occasional and with certain etiologic features that differentiates it from the involvement of other spinal segments. We report here two patients with no vascular risk factors who had an infarction in the territory of the cervical anterior spinal artery after physical exertion in one of the patients. We suggest the compression of anterior radicular-medullary arteries or the cervical anterior spinal artery against the anterior bone wall of the spinal canal as possible pathogenic mechanism.

Female↗
PubMed1996

[Spontaneous dissection of the vertebral artery].

Spontaneous dissection of the vertebral artery (VA) is an infrequent cause of vertebral-basilar ischaemia in children and young adults, being responsible for 4% of cases of ischaemic infarct in this age group. The distinction between spontaneous dissection and traumatic dissection helps to clarify its vascular tendency, not brought on by laceration of the vessel wall secondary to traumatism. It appears clinically with neck pain and/or headache, followed by a clinical picture of ischaemia in the vertebral-basilar area. Diagnosis is based on clinical suspicion and identification of the angiographic signs of dissection prognosis is favourable with good recuperation in 88% of cases and low recurrence risk. We present a series of seven patients with ischaemic stroke of the brainstem brought about by spontaneous VA dissection. We studied the patients using computerized tomography (CT) scan, magnetic resonance (MR) and brain angiography. The group comprised six men and one woman aged from 9 to 44 years. In one case localization was intracranial, in five there was earlier arterial pathology (hypoplasia or dysplasia) and in the remaining case dissection was bilateral. After a long-term follow-up of between one and seven years, not one of our patients showed any recurrence of ischaemic signs. We would suggest that spontaneous VA dissection should be considered in differential diagnosis in clinical pictures of vertebral-basilar ischaemia in children and young adults since most probably its frequency is greater than that currently supposed. The discussed data would support underlying arterial pathology as a tendency factor.

Adult↗
PubMed1996

[Colonic tuberculosis as a cause of rectal bleeding in 2 patients with HIV infection].

BACKGROUND: Extrapulmonary tuberculosis is a relatively frequent disease in patients with HIV infection. This may be observed coinciding with pulmonary involvement or without diagnostic data of the same. Within extrapulmonary involvement, gastrointestinal involvement is one of the least frequently observed and its diagnosis is very difficult due to the scarce clinical suspicion because of the unspecific symptomatology. METHODS: Segmentary colonic tuberculosis was diagnosed in two patients presenting rectal bleeding. The diagnosis was neither clinically nor endoscopically suspected and only histologic and microbiologic study of the biopsies led to establishment of the diagnosis. Pulmonary involvement was also seen in one of the 2 patients. RESULTS: Medical treatment was initiated following the diagnosis. The evolution was good in one patient, while the other developed a picture of massive rectal bleeding requiring surgical resection following which the patient died due to complications. CONCLUSIONS: Colonic tuberculosis is an infrequent disease in patients with HIV infection. Only a high index of clinical suspicion along with adequate histopathologic and microbiologic study of all the colonic lesion biopsies can establish the real frequency of this disease in this group of patients.

Adult↗
PubMed1995

Hypersomnia after tegmental pontine hematoma: case report.

We describe polysomnographic studies of a 44 years-old man who showed a defect in the central nervous regulation of the sleep-waking cycle (SWC), hypoventilation and cardiovascular hyperactivity after a right-sided tegmental pontine hematoma. A significant increase in total sleep time mainly depending upon stage 1 + 2 was observed. Predominant unilateral damage to the medial and central region of the reticularis pontis oralis (Poo) nucleus, extending into the central part of the rostral reticularis pontis caudalis (Poc) nucleus, was presumably responsible for the hypersomnia in this patient.

Adult↗
PubMed1995

Sympathetic skin response: correlation with autonomic and somatic involvement in multiple sclerosis.

The sympathetic skin response (SSR) was studied in 63 multiple sclerosis (MS) patients, 54 with clinical definite and 9 with clinical probable form. The test was recorded from palms and soles and induced by electric stimulus. SSR was abnormal, absent or mildly delayed, in 26 patients (41%). The average score in the Kurtzke Expanded Disability Status Scale was higher in patients with abnormal SSR, showing a positive correlation with the latencies (p < 0.05). When compared to other evoked responses (somatosensory, brainstem auditory and visual evoked potentials), only visual evoked potentials showed a positive correlation (p < 0.05). Among the signs of autonomic dysfunction, bladder impairment was the most frequently associated with altered SSR (p < 0.05). These results could be probably due to the higher incidence of these abnormalities during the course of the disease. It is concluded that SSR is a simple test for a dynamic evaluation of MS, well correlated with the degree of disability, able to detect subclinical lesions in the sympathetic tracts, but with slight localizing value. It has also a low sensitivity for autonomic impairment related only with the bladder dysfunction. These facts exclude the SSR as a primary diagnostic tool in MS.

Adolescent↗
PubMed1994

Benign mitochondrial myopathy with decreased succinate cytochrome C reductase activity.

In most of the cases previously described, the defect on complex II was suggested by low activity of succinate cytochrome C reductase (SCCR). The clinical pattern of the previous 10 cases is heterogeneous and may be limited to one particular tissue or be of a more general nature. We report a 22-year-old-woman, daughter of consanguineous parents, with generalized muscle weakness, easy fatigability and benign course, who showed a decrease of SCCR activity in mitochondria of muscle fibers. Free carnitine (FC) concentration was decreased in muscle as well. The muscle biopsy showed a mild variation in fiber size, with fiber type I predominance, subsarcolemmal oxidative DPNH accumulations, excess of neutral lipids and abnormally large mitochondria with paracrystalline inclusions. A possible inheritance pattern is discussed. Coenzyme Q10 therapy in this patient induced a significant increase of global MRC index score and a decrease of the turns-mean amplitude ratio in the automatic analysis of the EMG.

Adult↗
PubMed1994

[Clinical and investigative approaches in mitochondrial diseases. A review of 15 cases].

The results of laboratory investigations in concerning 15 patients suspected of mitochondrial disease (MD) are presented. Our purpose is to provide an outline of the investigative modalities that support the clinical suspicion and have been found to be useful in the diagnosis. Five clinical groups were studied including 5 exercise intolerances (2 with inflammatory myopathy), 3 with myopathies (1 with dilated cardiomyopathy), 2 with progressive external oftalmoplegia (1 associated with cerebellar ataxia+epilepsy+hypertrophic cardiomyopathy+pes cavus), 4 with encephalopathies (3 with myoclonic encephalopathies with ataxia and dementia and 1 with epilepsy and tremor), and 1 with metabolic acidosis and cardiomyopathy. We used the following categories of investigative procedures: clinical phenotype analysis including pedigree study, neurophysiological tests, bicycle ergometric evaluation, neuroimaging, microscopic study of skeletal muscle biopsy, post-mortem examination, biochemical assays and molecular genetic studies. EMG showed myopathic changes in 5 cases, features of neuropathy in 2, mixed myopathic and neuropathic pattern in 1 and nonspecific changes in 3. EMG was normal in 3 patients. The most common skeletal muscle abnormalities were variation in fiber size (60%), lipid inclusions (33.3%), oxidative subsarcolemmal aggregates (26.7%) and ragged-red fibers (26.7%). Electron microscopy revealed mitochondrial abnormalities in 8 out of 14 patients' muscle biopsies, and in myocardiac and hepatic tissues of another. Site of biochemical defect was located in 12 patients. Complex I defect in 6, complexes I+IV deficiencies in 3, complex II defect in 1, complex IV deficiency in 1, complexes II+IV deficiencies in 1, and complex III defect in 1. In 2 patients the biochemical defect was not located. Mitochondrial DNA alterations were not found in 7 investigated patients. The clinical spectrum of MD has become increasingly wider. After the clinica suspicion, the diagnosis depends up on the appropriate use of skeletal muscle biopsy, biochemical investigations and molecular genetic techniques. Conventional EMG and automatic measurement of the electromyogram are particularly helpful in confirming the clinical suspicion in patients with predominantly central nervous system disease or in cases in which clinical signs are few.

Adolescent↗
PubMed1994

[Idiopathic granulomatous angiitis of the central nervous system].

We diagnosed idiopathic granulomatous angiitis of the central nervous system in a 51-year-old man by leptomeningeal and cortical biopsy. The patient's disease was prolonged, with symptoms recurring over a period of 15 years. Treatment with prednisone and cyclophosphamide produced total remission after a follow-up of 22 months. Computerized tomography was less sensitive and revealed fewer lesions than did magnetic resonance imaging. Angiography was not sensitive and leptomeningeal and cortical biopsy were essential for diagnosis in this patient.

Age of Onset↗
PubMed1990

[Wilson's disease: computed tomography and magnetic resonance imaging].

Wilson's disease is an autosomal recessive hereditary disease in which the capacity of biliary copper excretion is reduced, resulting in a toxic accumulation of this metal in the liver, brain and other organs. The neuroimaging techniques, computed tomography (CT) and nuclear magnetic resonance (NMR), have been incorporated to the diagnostic workup in patients with suspected Wilson's disease (WD). We report two patients with WD in whom CT and NMR were carried out for the evaluation of the central nervous system (CNS). The lesions appeared as hypodense areas in CT or signal abnormalities in NMR over the involved structures: putamen, caudate nucleus, cerebellar dental nucleus, red nucleus and subcortical white matter. In one of the patients, hypointense signal areas were found over both putamen nuclei in T-2 times of NMR, which might correspond to cavitary necrosis or copper deposition. The lesion distribution suggests that vascular lesions might play a role in the mechanisms of tissue damage. These findings show that CT and NMR are very helpful to evaluate WD. NMR images are quite characteristic of this disorder.

Adolescent↗
PubMed1989

Differentiation of smooth muscle in the genital tract of the female mouse and its temporal relation with the development of the Wolffian nerve.

The development of the smooth muscle in the genital tract of the female mouse was studied by light and electron microscopy before and after birth. These studies showed that: a) between 13 days of fetal development and 2 days after birth the cells surrounding the Mullerian duct were undifferentiated and showed a fibroblast-like appearance; b) between 3 and 10 days after birth the cells acquired several characteristics of smooth muscle but they did not seem fully mature; c) between 30 and 180 days after birth the cells acquired a mature appearance; and d) the Wolffian nerve reached the Mullerian duct surrounding tissue before the start of smooth muscle differentiation.

Animals↗