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Biomedical subjects

G Sevlever

Publications and source records attributed to G Sevlever.

At least 19 recordsLinked to original sources
PubMed2006

Immune reconstitution inflammatory syndrome associated with PML in AIDS: a treatable disorder.

An HIV-1-infected patient with progressive multifocal leukoencephalopathy presented clinical deterioration and contrast-enhancing lesions on brain nuclear MR after the initiation of highly active antiretroviral therapy (HAART). Brain biopsy identified an inflammatory reaction compatible with immune reconstitution inflammatory syndrome. Treatment with corticosteroids and transient suppression of HAART led to marked neurologic improvement.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Characterization of brain tumors by MRS, DWI and Ki-67 labeling index.

With the advent of fast imaging hardware and specialized software, additional non-invasive magnetic resonance characterization of tumors has become available through proton magnetic resonance spectroscopy (MRS), hemodynamic imaging and diffusion-weighted imaging (DWI). Thus, patterns could be discerned to discriminate different types of tumors and even to infer their possible evolution in time. The purpose of this study was to investigate the correlation between MRS, DWI, histopathology and Ki-67 labeling index in a large number of brain tumors. Localized proton spectra were obtained in 47 patients with brain tumors who subsequently underwent surgery (biopsy or tumor removal). We performed MRS with short echo-time (30 ms) and metabolic values in spectra were measured using an external software with 25 peaks. In all patients who had DWI, we measured apparent diffusion coefficients (ADC) in the same region of interest (ROI) where the voxel in MRS was located. In most tumors the histological diagnosis and Ki-67 labeling index had been determined on our original surgical specimen. Cho/Cr, (Lip+Mm)/Cr, NAA/(Cho+Cr) and Glx/Cr indexes in MRS allowed discriminating between low- and high-grade gliomas and metastases (MTs). Likewise, absolute ADC values differentiated low- from high-grade gliomas expressed by Ki-67 labeling index. A novel finding was that high Glx/Cr in vivo MRS index (similar to other known indexes) was a good predictor of tumor grading.

Adult↗
PubMed2002

Insomnia associated with thalamic involvement in E200K Creutzfeldt-Jakob disease.

BACKGROUND: Insomnia with predominant thalamic involvement and minor cortical and cerebellar pathologic changes is not characteristic of familial Creutzfeldt-Jakob disease (CJD) but is a hallmark of fatal familial insomnia. OBJECTIVE: To report a 53-year-old woman with intractable insomnia as her initial symptom of disease. METHODS: The authors characterized clinical, pathologic, and molecular features of the disease using EEG, polysomnography, neurohistology, Western blotting, protein sequencing, and prion protein (PrP) gene (PRNP) analysis. RESULTS: The patient developed dysgraphia, dysarthria, bulimia, myoclonus, memory loss, visual hallucinations, and opisthotonos, as well as pyramidal, extrapyramidal, and cerebellar signs. Polysomnographic studies showed an absence of stages 3 and 4, and REM. She died 8 months after onset. On neuropathologic examination, there was major thalamic involvement characterized by neuronal loss, spongiform changes, and prominent gliosis. The inferior olivary nuclei exhibited chromatolysis, neuronal loss, and gliosis. Spongiform changes were mild in the neocortex and not evident in the cerebellum. PrP immunopositivity was present in these areas as well as in the thalamus. PRNP analysis showed the haplotype E200K-129M. Western blot analysis showed the presence of proteinase K (PK)-resistant PrP (PrP(sc)) with the nonglycosylated isoform of approximately 21 kd, corresponding in size to that of type 1 PrP(sc). N-terminal protein sequencing demonstrated PK cleavage sites at glycine (G) 82 and G78, as previously reported in CJD with the E200K-129 M haplotype. CONCLUSIONS: Insomnia may be a prominent early symptom in cases of CJD linked to the E200K-129M haplotype in which the thalamus is severely affected.

Amino Acid Sequence↗
PubMed2001

Evidence for reflex activation of experiential complex partial seizures.

Reflex activation of seizures by thoughts or mental images is suggested by patients but has not been objectively demonstrated. The authors present a report of a man with experiential complex partial seizures reliably activated by thinking about his family home. During monitoring, such seizures were repeatedly induced in this way. Seizures were refractory to antiepileptic drugs, but ceased after left temporal resection. Pathologic examination showed cortical dysplasia.

Adult↗
PubMed2001

Bone metastases from secondary glioblastoma multiforme: a case report.

Extraneural metastases of glioblastoma multiforme (GBM) are a relatively rare occurrence which usually manifest after de novo GBM. We report a case of a patient with an oligodendroastrocytoma who developed over a period of 12 years malignant progression to glioblastoma followed by multiple cytologically confirmed bone metastases. No 1p deletions were detected in the original tumour. GBM cells disclosed the EGFr(+) and p53(-) immunophenotype more characteristic of a primary GBM.

Adult↗
PubMed2000

[Chronic hereditary ataxic polyneuropathy].

Sensory ataxic polyneuropathies are characterised by the presence of sensory ataxia due to damage to large myelinated sensory fibres, with total or relative preservation of muscle strength, pain and temperature sensation. Hereditary ataxic polyneuropathies are exceptional and very few families with this disorder have been reported so far. We here describe the neurological, electrophysiological and sural nerve biopsy data of four siblings with an ataxic chronic polyneuropathy, starting after age 50. They had an ataxic gait which worsened in darkness, horizontal nystagmus, hypo or areflexia, and severe impairment of limbs' propriocaption. Nerve conduction studies showed absent sensory nerve action potentials in all nerves tested. Somatosensory evoked potentials showed reduced amplitude and prolonged latencies. Sural nerve biopsy showed a severe loss of myelinated and unmyelinated fibres. Symptoms slowly progressed over the years. The recognition of this syndrome is important in the search for the etiology of chronic ataxic neuropathies.

Aged↗
PubMed1999

Tuberous sclerosis associated with MDR1 gene expression and drug-resistant epilepsy.

Intractable seizures are the most common manifestation in severe cases of tuberous sclerosis. Multidrug resistance type 1 (MDR1) gene expression is directly linked to the resistance of tumor cells to chemotherapy as the major cause of treatment failure, but it has not been reported in tuberous sclerosis cells nor has the relationship between the MDR1 gene and antiepileptic drugs been described. A 4-month-old female is described with poorly controlled seizures secondary to tuberous sclerosis. The patient was treated with antiepileptic drugs, including phenytoin, phenobarbital, and lorazepam, without improvement of symptoms. Phenytoin blood levels were invariably subtherapeutic and ranged from 0.45 to 3.55 microg/mL, despite several consecutive intravenous loading doses. Surgical treatment with total resection of the brain lesions was performed as a last resort. Immunohistochemical analysis of the resected tissues revealed high levels of P-glycoprotein 170 expression, the product of the MDR1 gene. Both MDR1 gene expression and persistently low phenytoin levels likely share a common pathway liable to induce drug-resistant epilepsy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Progressive multifocal leukoencephalopathy in a patient with hypogammaglobulinemia.

We describe a child with congenital hypogammaglobulinemia that was diagnosed at 13 months of age. When he was 4 years old, gait disturbances began. The main neurological manifestations were progressive spastic tetraparesis and intellectual and speech deterioration. No infectious agent was identified. A magnetic resonance imaging scan of the central nervous system revealed periventricular demyelinating areas in the frontal, temporal, and parietal lobes with cortical atrophy. Stereotactic brain biopsy confirmed the diagnosis of progressive multifocal leukoencephalopathy caused by JC virus. He was treated with intravenous and intraventricular cytarabine and interferon-alpha, and there was clinical improvement. We emphasize the need for brain biopsy as soon as a neurological complication is suspected in patients with congenital hypogammaglobulinemia for whom cerebrospinal cultures or polymerase chain reaction analyses are negative.

Agammaglobulinemia↗
PubMed1995

Childhood neuronal ceroid-lipofuscinoses in Argentina.

We report on 30 cases of neuronal ceroid lipofuscinoses (NCL), mainly diagnosed in 1985-1993 in Argentina, whose population is predominantly of European descent. Twenty-four cases were late infantile Jansky-Bielschowsky (LINCL) and 6 were juvenile Spielmeyer-Vogt (JNCL). Sex ratio was female:male, 20:10. Age range and mean at onset and at diagnosis for the LINCL cases were 1-6 years, mean 3.1, and 2-11 years, mean 5.5, and for the JNCL cases, 5-9 years, mean 7, and 9-18 years, mean 13, respectively. Cases were referred for biopsy after neurological examination, and most included complete electrophysiological [electroencephalography (EEG) with photic stimulation, electroretinography (ERG), and visual-evoked potential (VEP)], neuroimaging, and neurometabolic investigation. NCL was the first suspected clinical diagnosis, followed by mitochondrial encephalopathy in some cases of recent onset. Except for 1 case, clinical findings were homogeneous in LINCL, characterized by refractive epilepsy, mental regression and progressive deterioration, ataxia, myoclonia, and visual loss. Abnormal VEP, ERG, and EEG, with polyphasic high-voltage spikes when photic stimulation was performed at low frequency, were observed. Visual impairment and retinitis pigmentosa were early manifestations in 4/6 JNCL, followed by mental abnormalities, motor deterioration, and myoclonic jerks, while 2/4 followed an atypical course. In both variants inheritance was autosomal-recessive. Five out of 27 families had more than 1 affected member, 3 of whom were included in our series. Diagnosis was initially performed in conjunctival biopsy in 3 cases, skin in 5, muscle in 17, and brain in 5, though most cases had a concomitant biopsy from another tissue including nerve, and there was a single brain autopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Duchenne muscular dystrophy and myotonic dystrophy in the same patient.

We report on the first patient identified with myotonic dystrophy and Duchenne muscular dystrophy (DMD). The family of the propositus had a strong history of myotonic dystrophy, and there was an intrafamilial pathological expansion of the responsible CTG repeat between the mildly affected mother (160 repeats; normal 27 repeats) and her more severely affected son (650 repeats), and his sister (650 repeats). The propositus was an isolated case of Duchenne muscular dystrophy with marked dystrophin deficiency in muscle biopsy. The patient was still ambulatory post age 16. Myotonic dystrophy could interfere to some extent with the progression of Duchenne dystrophy. However, other interpretations are possible. Twelve percent of dystrophin revertant fibers as observed by immunohistochemistry could be sufficient to ameliorate typical DMD clinical severity, or the patient may present a somatic mosaic. The pathophysiological interactions of these two unlinked disorders are discussed at the clinical and histopathological levels.

Child↗
PubMed1995

Dysembryoplastic neuroepithelial tumor: morphological, immunocytochemical, and deoxyribonucleic acid analyses in a pediatric series.

Overtreatment by radiotherapy and/or chemotherapy for central nervous system tumors in infancy and childhood may be deleterious, so the recognition of surgically curable clinicopathological entities is mandatory. The dysembryoplastic neuroepithelial tumor is a complex multinodular lesion consisting of glial nodules, associated with a specific glioneuronal element and/or with focal cortical dysplasia, and occurring in young patients presenting with intractable, mostly complex partial, seizures without neurological deterioration. We report on 14 patients; 9 were from a series of 600 pediatric patients with intracranial central nervous system tumors studied at a single institution from 1988 to 1993, and 5 were referred from other pediatric hospitals. Six tumors were frontal, six were temporal, one was parietal, and one was occipitoparietal. Computed tomographic scans disclosed hypodense lesions with cystic appearances in 4 patients and slight focal postcontrast enhancements in only 2 patients, whereas magnetic resonance imaging, available for 7 of 14 patients, showed hypointense lesions in T1-weighted images and hyperintense lesions in T2-weighted images. Deformities of the overlying cranium were also observed in five patients. The age range at the time of surgery (excluding a 20-year-old male patient who underwent surgery at the main pediatric hospital) was 2.6 to 13 years, with a mean of 6.68 years. The male to female patient ratio was 10:4, and the duration of symptoms was 0.2 to 6 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Autosomal dominant neuromuscular disease with cylindrical spirals.

Cylindrical spirals (CS) have been reported in muscle biopsies from five individual cases, as well as in two belonging to one family where there was another affected member, clinically associated with cramps, pain, stiffness and/or weakness. Here we studied muscle biopsies of a 70-yr-old mother and her 52-yr-old son, the latter with an associated neuropathy, both with late clinical onset in whose family at least 10 other members, spanning five generations, were diversely affected by muscular weakness, gait disorders, motor impairment and/or scoliosis, featuring an autosomal dominant trait with variable expression. CS as the main pathological findings were observed by light microscopy mostly in type 2 fibres, consisting of subsarcolemmal or intermyofibrillar granular and/or rod-like clusters, bluish with haematoxylin, bright red with Gomori's modified trichrome, non- or lightly reactive with PAS, faintly coloured with NADH-TR, non-reactive with SDH or ATPase, strongly stained with non-specific esterase and myoadenylate deaminase. Ultrastructurally, CS appeared as concentrically wrapped lamellae 1-2 microns in diameter. On occasion CS merged into tubular vesicular structures strongly resembling tubular aggregates (TA). Dilation of terminal cisternae (TC) in their proximity supports an origin from the sarcoplasmic reticulum (SR). Variable gene expression possibly explains both the highly diverse clinical compromise and time of onset.

Adult↗
PubMed1991

Alzheimer's disease in a patient with posterior cortical atrophy.

Posterior cortical atrophy (PCA) is characterised by slowly progressive dementia with cognitive and perceptual deficits suggestive of bilateral parieto-occipital disease. A case is reported of a patient with PCA and neuropathological findings consistent with Alzheimer's disease.

Alzheimer Disease↗
PubMed1991

Clues and pitfalls in stereotactic biopsy of the central nervous system.

We present a 6-year experience on 307 stereotactic biopsy specimens of the central nervous system using Leksell's and Talairach's systems independently and either Leksell or Sedan needles. Patients with deep cerebral lesions (basal ganglia, parasellar, pineal, or third ventricle), those located in highly functional areas or those poorly defined on imaging studies, as well as candidates for brachytherapy, were selected. Smear examination during surgery was a routine procedure followed by conventional histologic methods. Ages ranged from 8 months to 81 years (mean, 33.64 years). The series comprised 258 tumors, 28 nonneoplastic cases, and 21 nondiagnostic samples. Of the 258 tumors, 179 were supratentorial, 28 were infratentorial, 36 were of the pineal area, and 15 were from sellar and suprasellar regions. Results of the histologic examination showed the following: astrocytic tumors, 148 (57.36%); oligodendroglial, 25 (9.68%); ependymal, six (2.32%); primitive neuroectodermal tumors, 17, including 14 pineoblastomas (5.45%) and three medulloblastomas (1.16%), seven lymphomas (2.71%), seven meningiomas (2.71%), four schwannomas (1.55%), eight craniopharyngiomas (3.10%), 12 germinomas (4.65%), and 20 metastases (7.78%). Nontumoral cases included six arteriovenous malformations, six pyogenic lesions, seven infarcts, two hematomas, one multiple sclerosis plaque, one Fahr, one progressive multifocal leukoencephalopathy, one tuberculosis, one cysticercosis, and one Chagas' encephalitis. Awareness of the cerebellar granular layer in infratentorial targets as well as glial reaction around craniopharyngiomas is essential to avoid misdiagnosis. Difficulties were basically differential diagnosis between well-differentiated astrocytomas vs glial reaction, as well as poorly differentiated neoplasms vs metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Giant axonal neuropathy (GAN): an immunohistochemical and ultrastructural study report of a Latin American case.

Giant axonal neuropathy (GAN), a progressive childhood disorder of intermediate filaments (IF), is characterized by a peripheral neuropathy and central nervous system involvement. Twenty-eight cases have been reported while several pathogenic hypotheses have been proposed. Sural nerve biopsy of a 10-year-old Argentinian girl showed a reduced number of myelinated fibers as well as several enlarged axons up to 30 microns in diameter, thinly myelinated or devoid of myelin sheath, displaying accumulation of neurofilaments (NF), but few microtubules (MT) beneath the axolemmal membrane. There was IF accumulation in Schwann and perineural cells as well as in melanocytes, fibroblasts, pericytes, endothelial and epithelial cells in both nerve and skin biopsy. Our findings strongly support GAN as a generalized IF disorder with MT segregation from NF in giant axons. Abnormal NF phosphorylation is suggested by heavy immunostaining of enlarged axons by a monoclonal antibody to NF phosphorylated determinants (SMI 31-Sternberger's) and lack of reaction with a monoclonal antibody with different phosphoepitopes affinity (SMI 34-Sternberger's).

Axons↗
PubMed1988

Epithelioid hemangioendothelioma of the central nervous system. Immunohistochemical and ultrastructural observations of a pediatric case.

In 1982, Weiss and Enzinger described a group of soft tissue tumors in adults that they called epithelioid hemangioendothelioma [Cancer 50: 970-981, 1982]. Such tumors have also been found in heart, bone, liver, lung and lymph nodes, and Kepes and Rubinstein described two intracranial examples in adults in 1986 [J. Neuropath. exp. Neurol. 45:319, 1986]. This report documents clinical and pathological features of an epithelioid hemangioendothelioma in the parietal lobe of a 4-year-old boy.

Brain Diseases↗