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Biomedical subjects

N Rizzuto

Publications and source records attributed to N Rizzuto.

At least 145 records · Page 8Linked to original sources
PubMed1982

Congenital toxoplasmosis: histological and ultrastructural study.

A case of congenital toxoplasmosis is reported in which the patient died at 32 days following seizures, coma and respiratory disturbances. Neuropathological examination showed numerous foci of softening throughout the brain. Histological examination disclosed widespread areas of inflammatory necrosis. Circumscribed areas of granulomatous inflammation were also found. Cysts containing a variable number of microorganisms and toxoplasmas free in the damaged areas were frequently observed. Small calcifications were scattered in the cerebral cortex and basal ganglia. Electron microscopy of postmortem brain specimens demonstrated toxoplasmas at various stages of development. The microorganism is enveloped by a two-layered membrane, the pellicle. Replication occurs in a vacuole inside the host cell. Following replication the newly formed parasites, the trophozoites, are released. Several replications without release may also occur with consequent cyst formation. The motile form of the toxoplasma, the tachyzoite, is fusiform with truncated cone shape of the anterior ending which is the presenting surface modified for host cell penetration. The modality of transplacental transmission and the clinical syndromes associated with toxoplasma infection are discussed. EM even of post mortem material contributes to knowledge of the structure of the parasite and of its life cycles.

Brain↗
PubMed1982

Prosopagnosia. Report of four cases.

4 patients with prosopagnosia are described. They presented associated neuropsychological deficits (achromatopsia, topographical disorientation) and visual field defects. In 1 case, gross pathological examination revealed bilateral symmetrical infero-medial occipito-temporal infarcts. In 2 other cases, computer tomography (CT) demonstrated bilateral inferior temporo-occipital infarction. In 1 case CT showed only occipital infarctions in the occipital lobes. This brings to 16 the number of anatomically studied cases of prosopagnosia (8 by necropsy, 8 by CT). In contrast to clinical localization, which often indicates only a right cerebral lesion, all anatomically verified cases of prosopagnosia exhibit bilateral lesions in the posterior cerebral artery distribution.

Adult↗
PubMed1981

Involvement of the central nervous system in non-Hodgkin's lymphoma.

Fifteen of 146 (10%) adult patients with non-Hodgkin's lymphoma showed clinical and pathologic evidence of involvement of the central nervous system (CNS): in 6 patients, the CNS lymphoma was present at the onset of disease, in 3 of them it was the only sign detected. In the remaining 9 cases, CNS involvement appeared during the course of systemic disease. In all cases symptoms related to infiltration of the CNS were associated with advanced disease (stage IV); bone marrow or bone involvement was found in 9 patients (60%). The histologic subtypes were mostly of high-grade malignancy according to the Kiel classification: immunoblastic (3), centroblastic (3), Burkitt type (2), lymphoblastic (1), LP immunocytoma in polymorphic variant (3), unclassifiable (3). The prominent signs and symptoms of CNS lymphoma are listed: the cranial nerve palsies are the most common finding. The principal means of detecting CNS involvement are discussed: cerebrospinal fluid cytology, brain scan and CAT scan were the most useful diagnostic procedures. The reported data allow identification of patients at high risk of CNS lymphoma: this includes histologies of high-grade malignancy, advanced stage of disease, and bone marrow or bone infiltration. Therefore, either intensive systemic chemotherapy or CNS prophylaxis are recommended for patients with high risk of CNS disease.

Adult↗
PubMed1981

An unusual case of meningeal gliomatosis.

A case of meningeal gliomatosis following a primary spinal cord tumor is reported. The clinico-pathological features of this unusual extension of a spinal glioma are described. The rare incidence of this malignancy and its occurrence in young patients only are stressed. The possible pathophysiological events leading to the diffuse dissemination of the neoplastic cells are discussed.

Adult↗
PubMed1981

Peripheral neuropathy associated with immunoglobulin disorders an immunological and ultrastructural study.

Light-, electron microscopic and immunopathological findings in a nerve biopsy of a patient with peripheral neuropathy associated with monoclonal gammopathy are reported. Loss of fibers, Wallerian-like degeneration and segmental demyelination were the most important features observed in light microscopy. In E.M. widening of the peripheral lamellae of myelin sheaths and occasional aspects of hypermyelination were seen. Immunoperoxidase study showed binding of IgM (k light chain) on the myelin sheath. The possible pathogenetic implications of these findings are discussed.

Aged↗
PubMed1981

Friedreich's ataxia. A light- and electron microscopic study of peripheral nerve biopsies.

Sural or superficial peroneal nerve biopsies of patients with clinical diagnosis of Friedreich's ataxia were studied. Patients were divided in two groups, typical and abortive forms: loss of fibers accompanied by axonal atrophy and segmental demyelination are the basic changes in both groups, although the decrease in number of myelinated fibers was most severe in typical FA. In the cases with slower progression there is a tendency to form onion bulb complexes.

Atrophy↗
PubMed1981

Lumbar epidural Ewing sarcoma. Light and electron microscopic investigation.

The clinicopathological findings in a child with extraskeletal Ewing sarcoma are described. The patient complained of pain in the lower back and difficulty walking. An extraskeletal, epidural, friable tumor, 2-3 cm long was removed from the epidural space. It had no relationship with the bone structures. Light and electron microscopic examination of the tumor led to the diagnosis of Ewing sarcoma. The morphological aspects of this neoplasia and the problem of the differential diagnosis with other small cell tumors of the epidural space are discussed.

Adolescent↗
PubMed1981

Gliomatosis cerebri diffusa. A case report.

The clinico-pathologic findings in an additional case of gliomatosis cerebri are reported: a 60-year-old woman died 8 months after the onset of a progressive deterioration of both the neurologic and mental conditions. Neuropathologic examination disclosed wide demyelination of both hemispheres, communicating through the corpus callosum, extending downward along the internal capsule to the brainstem structures. Cellular stains showed the presence of elongated astrocytes, multinucleated cells, mitotic and anaplastic figures, involving the demyelinated areas and the neighboring regions, and allowed the diagnosis of gliomatosis cerebri diffusa. The nosologic and pathogenetic aspects of this rare entity are discussed.

Autopsy↗
PubMed1981

Progressive peroneal muscular atrophy (Charcot-Marie-Tooth disease) associated with beta-thalassemia trait and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. A clinical and nerve biopsy case.

The case of a 22 year old woman presenting progressive peroneal muscular atrophy (PMA) is described. Electrophysiological and pathological studies demonstrated features of hereditary motor and sensory neuropathy -HMSN- type I. Laboratory findings showed two erythrocytic defects: beta-thalassemia trait and a glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. Unlike the past, these inherited disorders are associated with PMA.

Adult↗
PubMed1981

Changes in systemic arterial pressure during sleep in Shy-Drager syndrome.

Polygraphic findings during spontaneous nocturnal sleep of 2 patients suffering from Shy-Drager syndrome are reported. In both patients, total sleep time was reduced--sleep latency and awakening periods during the night being increased. Considerable reductions of rapid eye movement (REM) stage and, in 1 patient, also of deep non-REM (NREM; stages 3-4) were found. No apneas were recorded. In normal subjects, systemic systolic and diastolic pressure decreases during all the sleep stages; in our patients, arterial pressure values rose progressively during NREM sleep stages and showed a further increase in REM sleep. In all the sleep stages, sudden phasic swings of systemic arterial pressure were observed.

Aged↗
PubMed1981

Neurotoxic effects of 2,5-hexanedione in rats: early morphological and functional changes in nerve fibres and neuromuscular junctions.

The study was directed at detecting changes occurring in the early stages of the neurotoxic process induced by an intensive treatment with 2,5-hexanedione. Rats were injected intraperitoneally each day with 450 mg/kg of body weight for the first 14 days and then with 300 mg/kg for an additional 20 days. After 34 days of treatment typical axonal lesions were observed in the sciatic branches, together with electrophysiological signs of denervation in several fibres of the leg muscles. Morphological changes were also found in axons of the spinal cord and optic tracts. At an earlier stage (days 13 to 18), when clinical signs appeared, in the absence of morphological changes in peripheral nerves and of denervated muscle fibres, significant alterations in the functioning of several neuromuscular junctions were observed: increase in frequency and amplitude of miniature end-plate potentials, reduction of the mean quantal content of the evoked end-plate potential (epp) and absence of epp's in some fibres. These changes indicate a progressive functional impairment of nerve terminals which could possibly represent: (a) a primary alteration of the membrane resting and action potentials; (b) a secondary effect of changes in axonal transport. Both these hypothetical events could result from the inhibition of glycolitic enzymes of nervous tissue by 2,5-hexanedione.

Animals↗
PubMed1980

Diffuse Rosenthal fiber formation in adults. A case report.

A 20-year-old woman was admitted to the Hospital because of tetraparesis and respiratory failure, requiring mechanical ventilation. No disturbances of consciousness were associated. She had a residual left lower limb paresis from the age of 14, lasting unchanged until this final episode of bulbar paralysis. She did not recover: death occurred 3 months later. Neuropathological examination revealed Rosenthal fibers in the gray and white matter with typical perivascular and subpial distribution. Areas of mild demyelination were found in the periventricular white matter of the centrum ovale and in the hilum of the nucleus dentatus. In the brain stem the highest density of Rosenthal fibers was found in the medulla where the deposits extended deeply into parenchyma. The relationship of this case with Alexander's disease is discussed.

Adult↗
PubMed1980

n-hexane polyneuropathy. An occupational disease of shoemakers.

The epidemiological, clinical, electrophysiological and nerve biopsy findings of 3 cases of n-hexane neuropathy in shoe industry are reported. The disease affects more than 1 person working in the same environment, regardless of their specific role, and occurs in factories where standards of hygiene are low. In the most severe cases the picture of peripheral neuropathy is associated with symptoms suggesting a concurrent involvement of the central nervous system such as dysarthria, disproportionate ataxia of the gait, blurred vision, and sometimes, after the recovery of the peripheral neuropathy, appearance of leg spasticity. Light- and electron microscopic study of peripheral nerve biopsies shows that the toxic produces a primary axonopathy characterized by segmental swellings of the fibers, due to accumulation of filaments. Retraction of the myelin from the node and segmental demyelination are secondary to the axonal changes. Experimental models of hexacarbon neurotoxicity may offer an explanation for the anatomical substrate underlying the symptoms related to the involvement of the central nervous system.

Adolescent↗
PubMed1979

Arteriovenous aneurysm of the vein of Galen. A clinical, angiographic CT scan and neuropathological study.

An autopsied case of arteriovenous aneurysm of the vein of Galen in a 31/2-month-old female is reported. Arteriovenous aneurysm of the vein of Galen is a rare vascular malformation of the central nervous system consisting of a saccular dilatation of the vein which receives blood shunted through enlarged arteries. These peculiar structural and hemodynamic characteristics differentiate this particular malformation from the other AVMs of the central nervous system. In infants the arteriovenous aneurysm of the vein of Galen is characterized clinically by hydrocephalus and cardiomegaly. In the present paper the clinical features and diagnostic indications are discussed and, in particular, the role of computerized cranial tomography (CT) is emphasized as a rapid and noninvasive procedure for detection of intracranial disorders.

Brain↗
PubMed1978

Stiff-man syndrome associated with nocturnal myoclonus and epilepsy.

A case of stiff-man syndrome associated with primary generalised epilepsy is reported. In addition, nocturnal polygraphic recording revealed a nocturnal myoclonus. Detailed examination of the central nervous system did not show specific changes. There is no direct proof as to a spinal or supraspinal origin of the stiff-man syndrome. The absence of specific anatomical lesions may indicate a functional rather than a structural disturbance in its physiopathogenesis.

Brain↗
PubMed1978

[Experimental neuropathy due to acrilamide. Histological and ultrastructural studies (author's transl)].

The effects of acrylamide intoxication were studied both in peripheral (PNS) and central (CNS) nervous system of rats. The animals were sacrified at different time intervals from the beginning of the intoxication. Histological and ultrastructural studies of peripheral nerves and long tracts of the spinal cord revealed a severe axonopathy, characterized by swelling of axons, particularly in the paranodal regions due to accumulation of neurofilaments with almost complete disappearance of neurotubules. There was also aggregation of dense bodies, swollen mitochondria and multivescicolar bodies in subaxolemmal regions. Presynaptic endings in the anterior horns of the spinal cord and in the cuneate nuclei were swollen and filled with packed filaments. Fiber degeneration at different stages was seen both in PNS and in CNS. These changes are not specific for acrylamide intoxication, having been observed in other experimentally induced neuropathies (n-hexane, Mn-BK, CS2, ...), as well as in a variety of diseases both genetically determined and due to exposure to toxic substances (glue-sniffing, leather cement poisoning, antiblastic therapy, ...). Accumulation of filaments in peripheral and central axons is the pattern of fiber degeneration characterizing the dying-back neuropathies. These axonal changes are particularly marked in the pacinian bodies as well as in the distal segments of the fibres. These data support the hypothesis that a dying-back neuropathy might depend on the direct effect of the toxic substance on the most vulnerable segments of the fibres, rather than on the perikaryon of the nerve cell, as previously supposed.

Acrylamides↗