Biomedical subjects

M Ghobrial

Publications and source records attributed to M Ghobrial.

14 recordsLinked to original sources

PubMed2001

Parkinsonism associated with autosomal dominant bilateral striopallidodentate calcinosis.

Bilateral striopallidodentate calcinosis (BSPDC, also known as Fahr's disease, a misnomer), is a rare disorder where bilateral, almost symmetric, calcium and other mineral deposits occur in subcortical nuclei and white matter. Neurological manifestations vary but movement disorders are the most common. Of the movement disorders, parkinsonism predominates. We describe 6 patients with BSPDC associated with parkinsonism. Of the 6 patients, one patient from an autosomal dominantly inherited family who responded to levodopa, showed Lewy bodies in substantia nigra neurons and changes consistent with BSPDC. Another patient, from the same family with clinical evidence of parkinsonism and radiological and neuropathological evidence of BSPDC, did not show Lewy bodies. Ten patients with BSPDC and parkinsonism (without evidence of parathyroid dysfunction) were found in the literature. When parkinsonism is associated with dementia and cerebellar signs, obtaining a CT scan may be helpful as BSPDC often presents with the above three conditions.

Journal Article↗

PubMed1999

Apolipoprotein E immunoreactivity in human and mouse olfactory bulb.

We evaluated the distribution of apolipoprotein E (apoE) immunoreactivity in mouse and human olfactory bulbs. ApoE immunoreactivity was present in the olfactory nerve and around the glomeruli. Immunoreactivity was seen in somata that appeared to be glial. No neuronal staining was seen. The apoE immunoreactivity was also present in the mouse olfactory bulb subependymal layer. The specificity of immunoreactivity was confirmed with apoE-deficient mice (apoE gene knock-out mice, apoE KO) which did not display any immunoreactivity. The presence of apoE around glomeruli and nerve suggest that apoE is associated with the continuous degeneration and regeneration processes that occur in the olfactory nerve. Experimental manipulation of the olfactory nerve may be a useful technique to determine the functions of apoE in a well-defined neural system.

Adult↗

PubMed1998

Hemianopsia in dementia with Lewy bodies.

OBJECTIVE: To describe the pathologic changes that caused a left homonymous hemianopsia in a patient with dementia with Lewy bodies. DESIGN: Report of a case and postmortem studies. MAIN OUTCOME AND RESULTS: A 66-year-old woman experienced parkinsonism and left homonymous hemianopsia early in the course of a rapidly progressive dementia that culminated in death only 21 months after the onset of her symptoms. Postmortem examination revealed pathologic features consistent with the diagnosis of dementia with Lewy bodies. The only apparent explanation for her visual field deficit was a disproportionately large number of neurofibrillary tangles in the right striate, peristriate, and inferotemporal cortices. CONCLUSION: A clinically obvious homonymous hemianopsia can result from the occipital and inferotemporal cortical degeneration in dementia with Lewy bodies.

Aged↗

PubMed1998

Cancer treatment and growth cone-associated protein in human olfactory bulb glomeruli.

BACKGROUND: Growth cone-associated protein (GAP43) is found in growing axons and we hypothesized that systemic treatment with antineoplastic agents should disrupt regeneration of olfactory receptor cells. Disruption of regeneration should be evidenced by decreased presence of growing axons in the olfactory bulb. OBJECTIVE: To evaluate GAP43 in human olfactory bulb in normal controls and in individuals receiving treatment for neoplasms. DESIGN: Immunocytochemical studies were performed on autopsied human olfactory bulbs to identify both GAP43 and olfactory marker protein immunoreactivity. The former recognizes growing axons and the latter is a definitive marker of adult olfactory nerve. SUBJECTS: Twenty-seven subjects were evaluated. Seven had received either antineoplastic agents and/or x-irradiation of the whole head. Four subjects were young, untreated controls, 10 were age matched to the treated group, and 2 had neoplasms but did not receive antineoplastic agents or irradiation of the head. In addition, 3 subjects with end-stage renal disease were immunostained. RESULTS: Subjects treated with antineoplastic agents or x-irradiation of the whole head displayed no statistically significant loss of olfactory bulb glomeruli, but GAP43 immunoreactivity was markedly reduced in all but 1 subject (P<.32). The subjects with end-stage kidney disease showed frank loss of both GAP43 immunoreactivity and olfactory glomeruli. CONCLUSIONS: Treatment with antineoplastic agents apparently does not damage olfactory epithelium directly but inhibits growth of new axons into the olfactory bulb. This observation suggests that the quality of olfactory experience may change during the course of treatment with antineoplastic agents because the olfactory nerve is not replaced.

Adult↗

PubMed1997

The distribution of amyloid beta protein deposition in the corpus striatum of patients with Alzheimer's disease.

The distribution of amyloid beta peptide (A beta) was quantified in the corpus striatum and pallidum of 10 patients with Alzheimer's disease (AD) and three patients with both Alzheimer's disease and Parkinson's disease (AD-PD). A beta occurred almost exclusively in plaques that did not have neurites or amyloid cores. Caudate, accumbens nuclei and rostral putamen contained more of the diffuse plaques than did caudal putamen. No diffuse plaques were found in the neighbouring globus pallidus. This distribution of A beta deposition may reflect the distribution of diseased synaptic cortical afferents rather than a putative vascular source of A beta.

Aged↗

PubMed1995

Rarefied white matter in patients with Alzheimer disease.

Magnetic resonance head scans of 94 patients with probable Alzheimer disease (AD) and 45 patients with possible AD were examined prospectively to determine the prevalence and significance of rarefied cerebral white matter (leukoaraiosis) in patients with AD. Only 8.7% of patients with probable AD and 11.1% of patients with possible AD exhibited large confluent areas of subcortical leukoaraiosis. The remaining patients had variable degrees of leukoaraiosis surrounding the lateral ventricles. The magnitude of leukoaraiosis correlated with the patient's age but not with the Hachinski Ischemic and Mini Mental Status scores. Postmortem studies of two Alzheimer patients showed that their large confluent areas of subcortical leukoaraiosis consisted of rarefied white matter, gliosis, and arteriosclerotic small arteries. Eight additional Alzheimer patients who underwent autopsy had similar but less pronounced white matter changes limited to the periventricular regions of the cerebral hemispheres. Large confluent areas of rarefied subcortical white matter occur in a small minority of Alzheimer patients and are probably not caused by AD.

Aged↗

PubMed1993

Pathologic changes associated with intracranial hypotension and meningeal enhancement on MRI.

We report a patient with a 6-week history of postural headache due to intracranial hypotension whose MRI revealed findings typical of this syndrome, including diffuse meningeal enhancement following gadolinium infusion. Biopsy revealed extensive fibrocollagenous proliferation in the leptomeninges without evidence of inflammation. The pathologic changes in this patient, which occurred soon after the onset of symptoms, are probably related to the striking meningeal enhancement seen in this syndrome.

Adult↗

PubMed1992

Distribution of amyloid in the brainstem of patients with Alzheimer disease.

A4 protein (beta-protein, beta-amyloid) deposits were identified with silver stains in postmortem brainstem sections from 13 patients with Alzheimer disease (AD), 6 patients with mixed Alzheimer disease and Parkinson disease (AD-PD), 5 disease controls, and 2 elderly controls. A rostro-caudal gradient of A4 was found in patients with AD and AD-PD, such that A4 was most prevalent in the midbrain and least prevalent in the medulla. The brainstem of the controls contained little or no A4. The midbrain tectum and tegmentum contained the greatest densities of A4, but the red nucleus and substantia nigra pars reticulata were largely spared. This distribution of A4 suggests that A4 deposition is a function of synaptic connectivity rather than passive diffusion from vascular sources.

Adult↗

PubMed1989

The open opercular sign: diagnosis and significance.

Four children with varying clinical manifestations, but with the unifying feature of severe developmental delay, had bilateral enlargement of the sylvian fissure confirmed by magnetic resonance imaging (MRI). Subsequently, we examined 125 consecutive MRI scans of the heads of pediatric patients, looking for this insular exposure, and did not find it. Pathological correlation in 1 child revealed arhinencephaly and abnormal gyral formation; another is known to have migrational abnormalities. We suggest that the open operculum is a sign of arrested development and is associated with other anomalies and a poor prognosis.

Cerebral Cortex↗

PubMed1988

Periventricular white matter changes and dementia. Clinical, neuropsychological, radiological, and pathological correlation.

Forty-three patients with computed tomographic scan findings of decreased attenuation in the periventricular white matter (PVWM) region were studied. Clinical evaluation revealed presence of hypertension in 36 patients (84%) and cerebrovascular risk factors in 41 patients (95%). Unilateral or bilateral neurological deficits were present in 40 patients (93%). Neuropsychological evaluation in 27 of them revealed features of subcortical dementia. Magnetic resonance imaging in seven cases demonstrated high-intensity areas in the deep white matter region on T2-weighted imaging. Pathological evaluation in four patients revealed demyelination without inflammatory cells and infarctions in the PVWM region, lacunar infarctions in the basal ganglia and brain stem, and marked arteriosclerosis. The study indicated that most (95% in this series) of the patients with computed tomographic scan findings of decreased attenuation in the PVWM region had cerebrovascular risk factors and various neurological and neuropsychological features of subcortical dementia. Pathologically, these lesions represented areas of infarction and demyelination, along with diffuse arteriosclerosis.

Adult↗

PubMed1987

Pathologic characteristics of recurrent carotid artery stenosis.

Recurrent carotid stenosis occurs randomly in approximately 10% of patients undergoing endarterectomy. Previous studies have described several histologic features but have failed to clearly elucidate the pathogenesis of this disorder. To improve our understanding of this disease, we reviewed pathologic lesions from 20 patients with recurrent stenosis. All specimens had been fixed in formalin and were embedded in paraffin and had undergone routine microscopic studies. In addition, immunoperoxidase staining with anti-factor VIII for endothelial cells and anti-desmin and anti-actin for smooth muscle cells was performed. Recurrent stenosis had developed in 16 of the 20 specimens within 2 years of endarterectomy (early), whereas the remaining four cases occurred from 2 to 7 years after the original carotid endarterectomy (late). Endothelial cells were found lining the luminal surface of both early and late recurrent lesions. Six of sixteen early and three of four late specimens had areas of luminal surface covered with cells exhibiting immunoreactivity for anti-factor VIII. Cells showing immunoreactivity for actin or desmin and demonstrating the morphology of smooth muscle cells were found in 9 of 16 early restenotic lesions but in no late ones. Areas of endothelial cell lining of the recurrent carotid lesions in a substantial number of patients in this study represent a finding not previously described. The presence of these cells implies that a phase of the arterial healing after endarterectomy involves re-endothelialization. Contrary to previous reports, no significant role of thrombosis and/or intraplaque hemorrhage could be found to contribute to development of recurrent stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1987

Reevaluation of an experimental streptococcal canine brain abscess model.

An experimental cerebral abscess model in which alpha-hemolytic Streptococci were inoculated into the brain parenchyma of dogs was evaluated for assessment of antimicrobial therapy. Intracerebral ring-enhancing lesions were visualized by computerized tomography, but they resolved after time without therapeutic intervention. Histopathological study demonstrated evolution of the lesions into sterile granulomas. Quantitative cultures were performed and uniformly became sterile in the early cerebritis stage, approximately 3 days after bacterial inoculation. Therefore, this brain abscess model should not be utilized for the evaluation of new antimicrobial treatment regimens. Rather, other models which document persistent viable organisms within cerebral abscesses need to be developed.

Animals↗

PubMed1986

Adult intrasellar teratoid tumor.

Intracranial teratomas rarely occur in adults. The most common sites are the pineal followed by the suprasellar or hypothalamic areas. Infrequently, teratomas can arise within the sella turcica and mimic a pituitary adenoma or craniopharyngioma. Teratoid tumors contain tissue arising from only two of the three primitive germ layers, whereas teratomas have elements of all three. The following case illustrates the unusual occurrence of an intrasellar teratoid tumor in a 33-year-old man.

Adult↗

PubMed1984

Brain stem vascular malformation simulating a hemorrhagic metastasis: report of a case with pathologic correlation.

A 65-year-old woman with known breast carcinoma developed headaches, followed shortly by disequilibrium, vertical diplopia and dysarthria. Cranial computerized tomography (CCT) demonstrated a dense, irregularly enhancing pontine lesion with associated mass effect. She received dexamethasone (Decadron) and radiotherapy and subsequently expired. Postmortem examination disclosed a ruptured brain stem arteriovenous malformation within a massive hemorrhage along with necrotic atypical cells suggestive of metastatic disease.

Aged↗