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J Pimentel

Publications and source records attributed to J Pimentel.

At least 19 recordsLinked to original sources
PubMed2006

Ganglioglioma of conus medullaris.

Gangliogliomas are glioneuronal tumours of the young, and occur more frequently supratentorially. Among those uncommon cases in the spinal cord, the conus medullaris is an extremely rare site. We reviewed the literature of such cases and report another case of a ganglioglioma of the conus in a 13-year-old boy with an insidious sensory sensitive and motor deficit of the right lower limb. Subtotal resection was accomplished with no recurrence after two years of follow-up. As for the supratentorial locations, the extent of surgical resection is the main prognostic factor for gangliogliomas of the spinal cord, and they should be considered in the differential diagnosis of intramedullar neoplasm.

Adolescent↗
PubMed2005

The marrow cell continuum: stochastic determinism.

Traditional models of hematopoiesis have been hierarchical in nature. Over the past 10 years, we have developed data indicating that hematopoiesis is regulated in a continuum with deterministic and stochastic components. We have shown that the most primitive stem cells, as represented by lineage negative rhodamine(low) Hoechst(low) murine marrow cells are continuously or intermittently cycling as determined by in vivo BrdU labeling. When marrow stem cells are induced to transit cell cycle by in vitro exposure to cytokines, either IL-3, IL-6, IL-11, and steel factor or thrombopoietin, FLT3 ligand, and steel factor, they progress through cycle in a highly synchronized fashion. We have determined that when the stem cells progress through a cytokine stimulated cell cycle the homing, engraftment, adhesion protein, global gene expression, and hematopoietic differentiation phenotypes all change in a reversible fashion. This has led to the continuum model, in which, with cycle transit, chromatin is continually changing altering open transcription areas and providing a continually changing landscape of transcriptional opportunity. More recently, we have extended the changing differentiation profiles to differentiation into lung cells and found that non-hematopoietic differentiation also shows cycle related reversibly modulation. These observations all together support a continuum model of stem cell regulation in which the phenotype of the marrow stem cells is continually and reversibly changing over time.

Animals↗
PubMed2004

Pleomorphic xanthoastrocytoma of the cerebellum: illustrated review.

Although rarely, the usually benign, supratentorial, grade II astrocytic tumour pleomorphic xanthoastrocytoma (PXA) may arise from the cerebellum. A review of the published cases of these PXAs is made including the author's own case of a 40 years-old man with a right cerebellopontine angle tumour, which recurred after a gross total resection. The major clinical and histopathological features of cerebellar PXAs are discussed, and factors playing a role in their biological behaviour, like post-surgical medical treatment, genetics and extent of leptomeningeal seeding are stressed.

Adult↗
PubMed2004

Role of irrigation and wastewater reuse: comparison of subsurface irrigation and furrow irrigation.

Two different irrigation systems, subsurface drip irrigation and furrow irrigation, are tested to investigate the level of viral contamination and survival when tertiary effluent is used in arid and semi-arid regions. The effluent was injected with bacteriophages of PRD1 and MS2. A greater number of PRD1 and MS2 were recovered from the lettuce in the subsurface drip-irrigated plots as compared to those in the furrow-irrigated plots. Shallow drip tape installation and preferential water paths through cracks on the soil surface appeared to be the main causes of high viral contamination in subsurface drip irrigation plots, which led to the direct contact of the lettuce stems with the irrigation water which penetrated the soil surface. The water use efficiency of the subsurface drip irrigation system was higher than that of the furrow irrigation system. Thus, subsurface drip irrigation is an efficient irrigation method for vegetable crops in arid and semi-arid regions if viral contamination can be reduced. Deeper installation of drip tapes, frequent irrigations, and timely harvests based on cumulative heat units may further reduce health risks by ensuring viral die-off under various field conditions.

Agriculture↗
PubMed2003

Stereotactic biopsies of focal brainstem lesions.

BACKGROUND: Stereotactic biopsies of the brainstem (SBB) are a selected group of stereotactic operations owing to the lower incidence of brainstem lesions requiring biopsy, the greater complexity, and the higher risks of these procedures. Usually, the lower the lesion in the brainstem, the greater the risks involved. The approach of the different target locations by distinct routes, transcerebral and transcerebellar, is still a matter of debate. Moreover, pure medullary lesions are seldom biopsied, whereas diffuse brainstem lesions, typical of children's brainstem gliomas and rather frequent in most published series, depend less and less on the histopathological confirmation for treatment. In this study, the authors present their own experience on SBB aiming to discuss mainly their indications, approach routes choice, and procedure techniques. METHODS: The authors reviewed a series of 30 SBB (27 adults and 3 children) out of 450 stereotactic biopsies of the central nervous system performed for the last 10 years. All cases but one presented as focal brainstem masses, 19 mainly in the pons and 10 in the midbrain. Eleven lesions (10 in the midbrain and one midbrain-pontine) were approached by a transfrontal route. All the others were approached by a suboccipital transcerebellar route. RESULTS: Twenty-six (87%) out of the 28 cases (93%) where a positive histopathological result was obtained had a specific diagnosis: 18 tumors (14 astrocytomas, 2 primary brain lymphomas, 1 oligodendroglioma, and 1 ganglioglioma), 2 toxoplasmosis, 2 sarcoidosis, 1 aspergillus abscess, 1 vasculitis, 1 acute inflammatory demyelinating disease, and 1 progressive multifocal leucoencephalopathy. Four nontumoral lesions arose in patients with AIDS. Morbidity was restricted to 2 cases consisting of transient cranial nerve deficits. CONCLUSIONS: Stereotactic biopsies are specially useful for the diagnosis of focal brainstem lesions. Midbrain and midline lesions should be approached through the cerebrum, whereas most of the pontine lesions through the cerebellum. Overall, this procedure should be performed with "functional-like" precision and require some technical refinements to reach maximal accuracy with minimal morbidity.

Adolescent↗
PubMed2001

Epileptic seizures following subcortical infarcts.

Stroke is one of the most frequent causes of seizures in adulthood. Subcortical infarcts have been associated with post-stroke epileptic seizures, although less frequently than cortical ischaemia. We studied 113 patients from a hospital stroke registry. The patients had subcortical non-lacunar infarcts (64 striatocapsular infarcts, 13 thalamic, 8 choroidal artery territory, 28 internal border zone and white matter medullary infarcts) and at least 1 year of follow-up. Only 4 patients (3.5%) with striatocapsular infarcts suffered an epileptic seizure. Two seizures occurred within the first 24 h, 1 within the first month and 1 within the first year of stroke onset. Emboligenic cardiac conditions were significantly more common in patients with seizures (difference 37%; 95% confidence intervals 2-72%). Subsequently to subcortical infarct, epileptic seizures are infrequent, tend to occur early after stroke and have a very low 1-year recurrence risk.

Cerebral Infarction↗
PubMed2000

How is mechanical ventilation employed in the intensive care unit? An international utilization review.

A 1-d point-prevalence study was performed with the aim of describing the characteristics of conventional mechanical ventilation in intensive care units ICUs from North America, South America, Spain, and Portugal. The study involved 412 medical-surgical ICUs and 1,638 patients receiving mechanical ventilation at the moment of the study. The main outcome measures were characterization of the indications for initiation of mechanical ventilation, the artificial airways used to deliver mechanical ventilation, the ventilator modes and settings, and the methods of weaning. The median age of the study patients was 61 yr, and the median duration of mechanical ventilation at the time of the study was 7 d. Common indications for the initiation of mechanical ventilation included acute respiratory failure (66%), acute exacerbation of chronic obstructive pulmonary disease (13%), coma (10%), and neuromuscular disorders (10%). Mechanical ventilation was delivered via an endotracheal tube in 75% of patients, a tracheostomy in 24%, and a facial mask in 1%. Ventilator modes consisted of assist/control ventilation in 47% of patients and 46% were ventilated with synchronized intermittent mandatory ventilation, pressure support, or the combination of both. The median tidal volume setting was 9 ml/kg in patients receiving assist/control and the median setting of pressure support was 18 cm H(2)O. Positive end-expiratory pressure was not employed in 31% of patients. Method of weaning varied considerably from country to country, and even within a country several methods were in use. We conclude that the primary indications for mechanical ventilation and the ventilator settings were remarkably similar across countries, but the selection of modes of mechanical ventilation and methods of weaning varied considerably from country to country.

Data Collection↗
PubMed2000

Current issues on epileptic women.

Issues linked to epileptic women are being reviewed. Ovarian steroid hormones have a number of effects on the brain that predispose to epileptic activity. In particular, estradiol produces changes in the hippocampus synapses predisposing hyperexcitability associated with seizures. Also, menses and menopause periods, in which there are changing levels of steroid ovarian hormones, are associated with a particular appearing of seizures (catamenial epilepsy) and with phenotypic changes of previous ones. Epilepsy can affect the reproductive system, inducing endocrinal abnormalities (through disruption of cortical regulation of hypothalamus hormone release, and changes in the central nervous system concentration of steroid hormones induced by antiepileptics), infertility (linked to abnormalities in menstrual cycle or to the occurrence of polycytic ovaries, particularly in association with valproate treatment), and sexual disfunction (namely related to physiologic defects). Oral hormonal contraceptives should be performed using a pill with > 50mg of estrogen in order to prevent its potential loss of efficacy induced by enzyme-inducing antiepileptics. Concerning pregnancy, some topics should be discussed with, and advised to epileptic women, including: the possibility of withdrawal antiepileptics and the need of folic acid supplementation when planning a pregnancy; the risk of increased seizure frequency during pregnancy, and of the occurrence of obstetric complications; the increased risk of teratogenesis associated with antiepileptic therapy (mainly if in polytherapy); the need of vitamin K supplementation during the last month of pregnancy in order to avoid newborn haemorrhages; and the general absence of risk of breastfeeding even under sustained antiepileptic therapy.

Anticonvulsants↗
PubMed1998

Association between polymorphisms in the fibrinogen alpha- and beta-genes on the post-trauma fibrinogen increase.

Fibrinogen is an acute phase reactant, and therefore its plasma levels increase after severe injury. Polymorphisms in the fibrinogen alpha and beta genes have been found to be associated with plasma levels of fibrinogen, and it has also been suggested that they are associated with the fibrinogen increase in acute phase situations. In forty-five consecutive patients admitted to the Intensive Care Unit after acute cranial or thoracic trauma, we investigated the influence of four polymorphisms at the fibrinogen loci (-455G/A and BclI (beta gene), TaqI and T/A312 (alpha gene)) on the post-trauma increase of the fibrinogen levels. At admission, fibrinogen levels were comparable in the patients with the different genotypes for the four polymorphisms studied. However, patients carrying the -455A allele of the -455G/A polymorphism had a significantly wider variation and higher peak levels of fibrinogen, during their stay at the intensive care unit, than did the -455GA homozygotes (5.1 g/l (SD 1.3) and 5.9 g/l (SD 1.0), respectively, p<0.05). Such difference was not found for the other studied polymorphisms. The present study suggests that the increase of fibrinogen level in acute phase situations like severe trauma is associated with the beta-gene -455G/A polymorphism.

Adult↗
PubMed1997

Isolated lichen planus of the lip successfully treated with chloroquine phosphate.

Solitary lesions of lichen planus (LP) are often confused with other inflammatory or malignant epithelial lesions. We describe a 51-year-old woman who had had an LP of the lower lip for 11 years. She had undergone several oral and topical therapies with little improvement. The patient had an excellent response to chloroquine phosphate within 3 months. This report represents the third case of LP exclusively localized on the lower lip.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1996

Annular elastolytic giant cell granuloma--actinic granuloma?

A 56-year-old woman with annular elastolytic giant cell granuloma is reported. She had annular, slowly growing lesions on sun-exposed areas and the dorsum of one foot. Biopsies from both areas revealed a mid-dermal inflammatory infiltrate with many giant cells engulfing elastic fibres. The current nosological situation of this process is discussed. Actinic granuloma (AG) is a term coined by O'Brien in 1975 to describe a cutaneous process characterized by multiple annular lesions located on sun-exposed skin areas. The histopathology is defined by the presence of multinucleated giant cells containing elastic fibres at the lesion edge, and the absence of these fibres at the lesion centre. The nosology of this disease and the role of actinic exposure as a triggering factor for it has been much discussed in recent years. We report a new case of AG not limited to photo-exposed areas.

Female↗
PubMed1995

[New antiepileptic medications].

Progress made in the development of new antiepileptics (AEs) is justified by the high percentage of refractory patients to the available medical therapy (25%), although only a minority of cases are deemed suitable for surgical therapy. Yet, the ideal AE, that is, with a well-known mechanism of action, effective in monotherapy for all epileptic fits, with a perfect pharmacokinetic profile, with no adverse or teratogenic effects, with no drug interactions and available under many formulations, is far from being developed. The new AEs arise either from modification of already marked drug molecules or clinical formulations or from the effectiveness on the excitatory/inhibitory balance of the major neurotransmitters involved in the pathogenesis of seizures, the gamma-amino-butyric acid (GABA) as the inhibitory, and the glutamate (GLU) as the excitatory one. However, the mechanism remains unknown in a few of them. Those new AEs already marketed in Portugal (Vigabatrin), soon to be (Lamotrigine, Oxcarbazepine) or available abroad only (Gabapentin, Zonisamide) are review with special emphasis on their pharmacokinetic profile, side effects, interaction with other AEs, and clinical use. In conclusion, these new drugs have brought a very important advancement in the management of refractory patients, but the development of well-designed comparative trials involving both monotherapy and polytherapy has become important in order to develop useful strategies in the drug management of epilepsy.

Acetates↗
PubMed1995

[Spinal epidural empyemas].

We report ten patients harbouring spinal epidural abscess, aiming to evaluate the factors that may lead to an early diagnosis and that can eventually influence the prognosis. There were seven males and 3 females, with ages comprised between 17 and 66 years. Abscesses were localised mainly in the dorsal region. The most important predisposing factors were infections or other disorders know to be related with compromise of the immunological system. Back pain with or without signs of spinal cord involvement was the most frequent clinical presentation. The pretreatment average time was 16,3 days. Staphylococcus aureus was the most commun organism isolated. Erythrocyte sedimentation rate (ERS) was uniformly elevated, being the most important laboratory data for the diagnosis of this situation. Diagnosis was frequently made on clinical grounds but it was always confirmed by myelography with computed tomography or magnetic resonance. All patients were submitted to surgical drainage. Two patients recovered totally, 5 partially, 2 did not recover at all and 1 died. We conclude that the prognosis is related to the surgical delay and that it depends on the identification of the predisposing factors and the recognition of a clinical picture of spinal cord involvement associated to an elevated ESR. Magnetic resonance is the most reliable imaging technique.

Abscess↗
PubMed1994

[Aneurysmal bone cysts of the spinal canal].

Aneurysmal bone cysts (ABC) are rare bone tumors of controversial pathogenesis. In 15% of cases, they are localized in the vertebrae. Despite the absence of anaplasia, their volume and localization are often responsible for incomplete surgical resection. The authors present 5 cases of primary vertebral ABC, 4 females and one male, localized in cervical (3 cases), dorsal (1 case) and lumbar (1 case) spine. Symptoms included rachialgia and torticollis. Radiological and histopathological examination disclosed the typical features of ABC. Pre-operative embolization (in 3 cases) and surgery (complete exeresis in all cases except one) were the therapeutic procedures. During a 39 month median period of follow-up, there was one local recurrence. The only case of incomplete exeresis show not did any evidence of progression until 36 months after operation.

Adolescent↗