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Biomedical subjects

A Ugarte

Publications and source records attributed to A Ugarte.

14 recordsLinked to original sources
PubMed2007

Antimalarials may influence the risk of malignancy in systemic lupus erythematosus.

BACKGROUND: Recent studies suggest that antimalarials have antineoplastic properties. OBJECTIVE: To investigate whether antimalarials decrease the risk of cancer in systemic lupus erythematosus (SLE). METHODS: An observational prospective cohort study was carried out. 235 patients were included in the study at the time of diagnosis (American College of Rheumatology criteria). The end point was the diagnosis of cancer. Kaplan-Meier cancer-free survival curves for patients treated and not treated with antimalarials were compared. A Cox proportional hazards model was fitted, with cancer as the dependent variable. Age at diagnosis, gender, treatment with azathioprine, cyclophosphamide and methotrexate, smoking, Systemic Lupus International Collaborating Clinics (SLICC) Damage Index 6 months after diagnosis, year of diagnosis and treatment with antimalarials were entered as independent variables. RESULTS: 209 (89%) patients were women. 233 (99%) patients were white. Mean (SD) age at diagnosis was 37 (16) years. Median (range) follow-up was 10 (1-31) years. 156 (66%) patients had ever received antimalarials. 2/156 (1.3%) ever-treated patients compared with 11/79 (13%) never-treated patients had cancer (p<0.001). Cumulative cancer-free survival in treated and not treated patients was 0.98 and 0.73, respectively (p<0.001). Adjusted hazard ratio for cancer among malaria drug users compared with non-users was 0.15 (95% CI 0.02 to 0.99). CONCLUSIONS: This study launches the hypothesis of a protective action of antimalarials against cancer in patients with SLE. This effect should be confirmed in larger multicentre studies.

Adolescent↗
PubMed2001

Regional and temporal progression of reactive astrocytosis in the brain of the myelin mutant taiep rat.

Reactive astrocytosis in taiep rats was shown by glial fibrillary acidic protein (GFAP) immunoreactivity measured by means of enzyme-linked immunosorbent assay and indirect immunofluorescence. Increased GFAP immunoreactivity was first observed in the brainstem of 15-day-old taiep rats and was widespread throughout all brain regions at 6 months of age. Characteristically, astrocytes were hypertrophic and displayed strong GFAP fluorescence. The pattern of these reactive cells may correlate with the process of dysmyelination in the taiep rat.

Animals↗
PubMed1997

[Pure alexia: presentation of three cases and review of the literature].

INTRODUCTION: Pure alexia is a syndrome characterized by the inability to read aloud in the absence of agraphia or apnasia. CLINICAL CASES: Three clinical cases showing this syndrome are presented. Case I had a left occipital lesion compatible with a subacute haematoma. He had problems with reading, visuo-spatial recognition, digital gnosia and memorizing texts. One year later there was considerable improvement in most of the sub-tests evaluated. There was still deficient colour naming right/left orientation and understanding of letters and words. Case 2 presented with a right homonymous hemianopia and slight left paresis. He had a small left occipital ischaemic infarct. One year later there was improvement on testing, with some deficit still in visual recognition, naming colours and memory. Case 3 presented with right homonymous hemianopia, slight right paresis and a left occipito-parietal expansive lesion. He had defective reading, choosing and naming of colours, right/left orientation and memory. On later evaluation, considerable improvement was seen. There was still colour agnosia, although less severe and mild 'laziness' of the right side. CONCLUSIONS: In the review of the literature, the disorder and the contributions of various authors, from Déperine in 1892 to the present day, are considered in detail.

Aged↗
PubMed1996

[Primary dural lymphoma].

We describe a 48-year-old woman with an intracranial tumor located in the meninges. Radiologic images were consistent with meningioma. Pathology showed that it was well differentiated and diffuse lymphocytic lymphoma. No evidence of systemic disease was found. Primary meningeal lymphomas generally infiltrate the subarachnoid space in a diffuse way and their presentation as focal and localized masses in unusual.

Brain Neoplasms↗
PubMed1995

Hereditary spastic paraparesis with dementia, amyotrophy and peripheral neuropathy. A neuropathological study.

Hereditary, probably autosomal recessive, spastic paraparesis in two siblings was associated with dementia of frontal lobe type, amyotrophy and peripheral sensory and motor polyneuropathy. Neuropathological findings correlate with neurological deficits, although neuron loss in the caudate and putamen, substantia nigra, and loss of Purkinje cells were clinically silent. Loss of neurons occurred in all cortical layers of the prefrontal lobe and superior temporal gyrus. Immunohistochemical studies showed reduced parvalbumin immunoreactivity in dendrites, and reduced numbers of calbindin D28k-immunoreactive cells, thus suggesting involvement of cortical local-circuit neurons. Myelin loss, ubiquitin-immunoreactive granular deposits, and nerve fibre degeneration in the white matter of the frontal lobes and corpus callosum were also observed. Cerebral and subcortical white matter abnormalities, together with atrophy of the thalamic dorsomedial complex and anterior nucleus, may have accounted for the development of severe dementia in this patient.

Brain↗
PubMed1992

Age-dependent changes in serotonergic modulation of yawning in the rat.

Serotonin (5-HT) effects on physostigmine (PHY)-induced yawning were studied in LY Sprague-Dawley rats by injecting Lu 10 171 (citalopram), a specific 5-HT uptake blocker, and two antagonists--methiothepine and ritanserin--which differ slightly in the selectivity of their actions on different 5-HT receptor subtypes. Infant and young rats show significant increases in PHY-induced yawning when preinjected with citalopram (5-10 mg/kg). Two-month-old animals show this effect only with 10 mg/kg. With adult animals (3-5 months old), the effect is the opposite: Yawning decreases. The facilitory effect in infant and young rats was counteracted by methiothepine but not by ritanserin, suggesting that it is mediated through 5-HT1A or 5-HT1B receptor subtypes. The inhibitory effect of citalopram in adult rats was unmodified by the two antagonists used, leaving open the possibility that it is mediated by 5-HT3 receptors.

Aging↗
PubMed1979

[A study of 14 cases of Bourneville's tuberous sclerosis, including two pathological reports and seven cases investigated by computer tomography (author's transl)].

The authors studied 9 girls and 5 boys, with ages ranging from 9 months to 26 years, suffering from Bournevilles tuberous sclerosis, for an average period of 7 years. The various types of epileptic attacks and their progression were studied as well as the degree of mental retardation. Only two of the children had a normal IQ. The accepted value of computer tomography examinations in this disease is confirmed. Pathological examinations were conducted in two cases, one complete (autopsy) and one partially only (histological examination of a paraventricular tumor removed by operation).

Adolescent↗
PubMed1978

Comparative incorporation of tritium from tritiated water versus tritiated thymidine, uridine or leucine.

Whereas the radiotoxicity of tritium has been extensively studied, comparatively little information exists on its long-term effects as a potential environmental pollutant, particularly at small dosage. This investigation was primarily aimed at assessing comparatively a possible carcinogenic potency of tritiated water versus radioactive precursors of DNA, RNA and proteins, namely tritiated thymidine, uridine and leucine in C57 Black mice. Tritium is largely released in the environment in the form of tritiated water. There are many uncertainties, however, as to how tritium is incorporated from tritiated water into cell constituents quantitively and qualitatively. In 1965, we reported on the carcinogenic effect of tritium in the form of tritiated thymidine on newborn C57 BL mice in the dose range of 0.3--1.5 muCi/g [Mewissen. 1965]. Hence the selection of tritiated water, and of tritiated precursors, in an attempt to evaluate their respective role in the tritium transfer process and to correlate their possible late effects with their specific patterns or sites of incorporation. This study deals with tritium incorporation from tritiated water and various precursors at the 1 or 10 muCi level. RSA values, i.e., the ratio of organically bound tritium per hydrogen content of dry tissue over aqueous tritium per hydrogen content of water, were estimated for newborn, juvenile and adult mice, at various time intervals (1, 8, 15, 22 and 29 days) following single administration of tritiated water, tritiated thymidine, uridine or leucine. The data available at this time show that administration of tritiated water (or precursors) result in a complex time dependent and age dependent residual activity dynamics both in the organic component and in the aqueous fraction of tissue. A few preliminary conclusions can be made. Following a single acute or brief exposure to tritiated water, values of activity become exceedingly small after a relatively short time period. In a steady state equilibrium, resulting from chronic exposure to tritiated drinking water, RSA values tend to stabilize. However, wide variations between various organs are to be expected, as suggested by their respective RSA values following a single exposure. In view of these observations, it would seem that a realistic estimate of the internal dose to the radiosensitive nucleus must take into consideration the age dependent incorporation of tritium from tritiated water, as well as the variation between organs. The carcinogenic risk has often been estimated from a uniform dose dependency model. The influence of time and space microdistribution of dose within tissues and more particularly at specific sites (such as DNA, RNA or protein) has received, as yet, little attention, as well as the relative contributions of the time sequence of dose absorption during the usually long latency period. Such factors, among others, may be critical in carcinogenesis from internal irradiation...

Age Factors↗
PubMed1978

[Intermediate forms of infantile spinal amyotrophy. Apropos of 20 personal observations].

The authors report 20 cases of infantile spinal amyotrophy, including 8 sporadic and 12 familial. There were 10 boys and 10 girls, the age of onset of the disease being between 1 and 5 years, with an average of 32 months. The clinical course is such that these forms may be easily distinguished from the classical Werdnig-Hoffman syndrome, by virtue of their later onset and their slower progression. Intermediate forms also differ from the Kugelberg-Welander pseudo-myopathic form in developing earlier and having a less benign clinical course. These features favour the existence of a series of intermediate forms situated between the two classical types, the definition and limitations of the infantile spinal amyotrophies being relatively imprecise.

Adolescent↗
PubMed1975

[Influence of perinatal factors on the latter evolution of function of the nervous system in the low weight newborn infant (author's transl)].

Psychomotor follow up study of a group of low weight newborn infants, with ages in between seven months and three years. The most important perinatal data registered in the records of each baby were studied in relation with the neurological examination and electroencephalogram. The incidence of pathological perinatal factors were studied in relation with latter development, as well as with the group incidence of neuroevolutive and electroencephalogram abnormalities. The great interest of this type of study as well as the convenience of been undertaken by a real paediatrical and neurological team, so to be able to obtain best results, and improve our knowledges on this subject, remarking the importance of perinatal factors and the possible influence of these, on latter neurological maturation of the infant, as well as the ned of establishing a correct ethiological diagnosis of certain type of subnormalities and their prevention is commented.

Birth Weight↗
PubMedDate not supplied

Time sequence of cancer occurrence. Implications in low level radiation risk assessment.

A total of 8,229 C57 Black mice of both sexes were randomly assigned to various groups. In some groups, mice aged 33 +/- 3 days were submitted to either sham, neutron or cobalt external radiation at 32, 45, 63, 88 and 123 mGy or at 18, 25, 36 and 51 cGy dose levels, respectively. In other groups, mice either at birth or weaning, were injected with tritiated thymidine or tritiated water, or were given tritiated water as drinking water for the entire lifespan. The main purpose of the experiment was to investigate the low dose-response relationship of cancer induction, especially leukemogenesis and to evaluate the excess risk, using actuarial age-specific rates. Following neutron or cobalt exposure, the phenotypic occurrence of lymphocytic lymphomas was earlier in appearance and higher in yield during the first decades of lifespan in irradiated groups versus matching controls, whereas such occurrence was markedly lower in yield at a later age. Under parallel experimental conditions, induction of reticulum cell lymphomas, however, was uniformly enhanced throughout the entire lifespan. Induction rates of all tumors (reticular and solid) pooled were significantly increased, and more so following cobalt than neutron irradiation. In mice injected with tritiated thymidine, the overall tumor incidence was increased monotonically throughout the lifespan. In mice exposed to tritiated water, the incidence of lymphocytic lymphomas was markedly increased throughout the lifespan, whereas no such effect was observed for reticulum cell tumors. In the light of tumor data analysis, it appears that selection of a particular type of tumor as a dependent variable for dose-response assessment cannot disregard the primary modulation of the whole tumor spectrum, In C57 Black murine leukemogenesis, the shape and structure of the dose-response regression curve over the entire lifespan dose not fit the linear-quadratic model. It is, however, theorized that our data are consistent with the two-mutation clonal expansion model, assuming creation of initiated cells which are added to the pool of spontaneously occurring initiated cells and implying that the excess risk is initially high at early age and then decreases with increasing age following exposure. It is concluded that murine radiocarcinogenesis investigation may contribute to improving the assessment as well as understanding the underlying mechanisms of low level radiation hazards.

Animals↗
PubMedDate not supplied

[The treatment of epilepsy. A therapeutic guide of the Catalan Society of Neurology].

INTRODUCTION: There have been major advances in the treatment of epilepsy over the past ten years, leading to marked changes in the way this illness is treated. However, the introduction of new drugs and new non-drug treatments have led to uncertainty in the medical profession with regard to their exact indications. For this reason, a group of neurologists of the Catalan Society of Neurology have drawn up guide-lines for the treatment of epilepsy. DEVELOPMENT: A panel of eight neurologists with a special interest in the diagnosis and treatment of epilepsy reviewed the literature to assess the data available regarding the treatment of epilepsy. A joint document was drawn up describing the basic rules for the use of antiepileptic drugs and the indications for other non-drug treatments. CONCLUSION: This document is an approved therapeutic guide to the treatment of epilepsy.

Dose-Response Relationship, Drug↗
PubMedDate not supplied

[Transient Brown-Séquard syndrome due to spontaneous spinal epidural hematoma].

Spinal epidural hematoma (SEH) is a low incidence injury. When the cause of bleeding is unknown, which occurs in 50% of the cases, we refer to it as spontaneous SEH. The clinical presentation is characterized by acute radicular pain followed by cord compression syndrome. Brown-Séquard syndrome is exceptional as a result of a SEH. Although standard treatment is prompt surgical evacuation of the hematoma, spontaneous resolution has also been reported. We present a case of spontaneous SEH in a 69 year-old man. An MRI revealed an hematoma in the right posterior epidural space extending from C6 to T2. The hematoma was manifested as a paresis of the right limbs and sensory loss of the left side below C7 level. During the first hours the neurological deficit was improved without treatment and consequently a conservative management was continued. After 72 h, the patient was completely recovered. We have reviewed the 14 cases of spinal epidural hematoma and Brown- Séquard syndrome previously reported, only 2 of them were resolved by conservative management. We conclude that when SEH presents as Brown-Séquard syndrome it usually has a more benign course and that in some cases a conservative management can be considered.

Acute Disease↗