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L Chimelli

Publications and source records attributed to L Chimelli.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Charcot-Marie-Tooth disease. Study of sural nerve biopsy in 41 patients].

We studied the pathological findings of sural nerve biopsy in 41 patients with Charcot-Marie-Tooth (CMT) disease. They were previously classified by the median motor conduction velocity (MCV) in two types. Type I (demyelinating) with 9 patients and type II (axonal) with 32 cases. In type I we found loss of myelinated fibers (unimodal histogram), demyelinated and remyelinated axons with numerous onion bulb formations. In one case there was thickness of myelin with thin axons (axonal atrophy). In type II there were seven patients with normal sural nerve biopsy. In 25 cases there were mild to severe loss of myelinated fibers. In 5 patients the number of myelinated fibers was increased due to the great regeneration of the axons. The electron microscopic studies in type II showed in a few cases small onion bulbs and in one case axonal atrophy. In type I there was no correlation between clinical severity and the loss of myelinated fibers, but there was relationship between the low MCV and the intensity of myelinated fibers. In type II we did not found any correlation between clinical course, MCV and pathological findings.

Adult↗
PubMed1994

Development of cortical fibres into the gracile nucleus of the rat: an ultrastructural study.

A study was made on the development of cortical synapses in the gracile nucleus of rats using degeneration methods. A total of 46 animals, 1 adult and 45 neonates whose ages varied from 1 to 7 days, had the right somatosensory motor cortex destroyed. The survival period varied from 1 to 30 days. Identification of axonal terminals in the gracile nucleus was also achieved by tracing the cortical fibres of 1 adult rat using horseradish peroxidase-wheat germ agglutinin (HRP-WGA). Degenerating axodendritic and axosomatic terminals that originated from cortical fibres were seen in the adult animal which survived 2 days. Their origin was confirmed by the presence of HRP-WGA inside the terminals. Light or electron microscopic changes were not seen, and in particular, the gracile nucleus was not smaller than in the control adult animals which survived 30 days or in neonates which survived 8-30 days, consistent with the small component of cortifugal fibres believed to terminate in secondary sensory nuclei. In neonates that survived a shorter period, terminal degeneration was only seen in cases operated at 4 days and later, indicating that cortical axons do not synapse in the gracile nucleus until postnatal day 4. Our results provide further support for the existence of a period in which the fibres approach their target but do not penetrate it to form synaptic junctions during the growth of cortical axons toward their targets, since previous studies have demonstrated that cortical fibres persisting to adulthood decussate completely at the level of the medulla at 12-36 h after birth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Value of the smear in the peroperative diagnosis of tumors removed in neurosurgeries].

The smear technique has been used for rapid diagnosis of tumors removed in neurosurgeries in many neuropathological centers. In order to assess the diagnostic accuracy of this technique, we examined 137 smears and made a cytohistological correlation. Our cases include 12 astrocytomas, 4 anaplastic astrocytomas, 26 glioblastomas, 7 oligodendrogliomas, 5 medulloblastomas, 8 schwannomas, 17 meningiomas, 13 pituitary adenomas, 20 metastatic tumors and 18 assorted tumors and non neoplastic lesions. The correct diagnosis was made in 91.2% of the cases which coincides to the literature. The knowledge of the localization and the characteristic morphologic features of some tumors were important for the diagnosis. The ability to recognize normal nervous tissue in smears was important even to help the surgeon to reach the tumor. We believe that the use of smears should be encouraged in our country in view of the simplicity of its preparation and accuracy of results.

Adult↗
PubMed1993

[Cytologic aspects of intracranial and spinal canal tumors].

We present the cytologic aspects of 137 tumors operated by neurosurgeons, including 12 astrocytomas, 4 anaplastic astrocytomas, 26 glioblastomas, 7 oligodendrogliomas, 5 medulloblastomas, 8 schwannomas, 17 meningiomas, 13 pituitary adenomas, 20 metastatic tumors and 18 assorted tumors and nonneoplastic lesions. We have also analysed cytologically samples of normal nervous tissue obtained from autopsies, aiming at its recognition and distinction from the neoplastic tissue in biopsies. The tumors were analysed in smears which were subsequently compared with the histological sections. Although it is important to observe cytological details in the tumor, occasionally cells are arranged in such a way, that an overview of the smear practically allows the diagnosis of the tumor.

Biopsy, Needle↗
PubMed1992

Pathology of the central nervous system in patients infected with the human immunodeficiency virus (HIV): a report of 252 autopsy cases from Brazil.

The central nervous system (CNS) was studied in 252 HIV-infected patients from the States of Rio de Janeiro and São Paulo in Brazil, the regions with the highest incidence of AIDS in the country. We compared the frequency and morphology of opportunistic infections and CNS changes caused by the HIV, with those described in other series and briefly analysed the risk factors involved in our cases. There were CNS lesions in 230 cases (91.3%), 30 (11.9%) with multiple infections and/or tumours. Most infections were opportunistic (65.4%), including 15.4% viral and 50% bacterial, fungal or protozoal infections. The most frequent was toxoplasmosis (34.1%), followed by cryptococcosis (13.5%), cytomegalovirus (CMV) infection (7.9%) and nodular encephalitis (6.7%). Primary lymphomas were observed in 4% of the cases and HIV encephalitis or leukoencephalopathy in 10.7%. Other opportunistic and HIV associated lesions were present in a limited number of cases and there were also vascular and non-specific lesions. Our study confirms the high frequency of CNS lesions in HIV infected patients. They are morphologically similar to those previously described. However, the higher incidence of toxoplasmosis and cryptococcosis, a lower incidence of viral opportunistic and HIV-associated lesions, and the presence of rarer lesions such as histoplasmosis and chagasic encephalitis, differ from other series, and may reflect geographical and/or socio-economic factors.

AIDS-Related Opportunistic Infections↗
PubMed1991

Lipomatous differentiation in a medulloblastoma.

A surgically resected medulloblastoma of the left cerebellum in a 42-year-old man contained numerous mature fat cells; many of these adipocytes expressed glial fibrillary acidic protein (GFAP), S-100 protein, and vimentin as seen by immunocytochemistry. The cellular parts of the tumor showed varying immunoreactivities for GFAP, S-100 protein, neuron-specific enolase, and synaptophysin. It is concluded that this tumor exhibits a unique spectrum of differentiation along multiple lines, including transformation of neuroectodermal cells to fat cells. The significance of this new type of differentiation in primitive neural tumors remains to be elucidated.

Adult↗
PubMed1991

Prominent cortical atrophy with neuronal loss as correlate of human immunodeficiency virus encephalopathy.

A 25-year-old homosexual AIDS patient presented with progressive cognitive, motor and behavioral disturbances consistent with HIV encephalopathy. CT scans demonstrated progressive diffuse brain atrophy. Neuropathology showed predominant cortical changes including severe neuronal loss corroborated by morphometry. Only minimal changes were found in the white matter and basal ganglia. Immunocytochemistry for HIV stained occasional microglial cells more markedly in the cerebral cortex. This suggests that HIV infection of the brain may cause predominant cortical nerve cell loss, and that HIV encephalopathy is not necessarily due to white matter lesions.

AIDS Dementia Complex↗
PubMed1991

Macrophages in human sensory ganglia: an immunohistochemical and ultrastructural study.

The paper describes the immunohistochemical and ultrastructural features of normal posterior root ganglia in a group of humans aged 1 day to 80 years and compares the findings with those seen in the ganglia of normal rats of various ages, some of which underwent permanent traumatic lesions of the sciatic nerve. In humans, cells with the immunohistochemical reactions of macrophages are present in small number at birth, most of them having an endoneurial position. Subsequently, their number increases and more of them are seen around neurons, where their processes intermingle with those of satellite cells. Ultrastructural studies confirm that, in addition to interstitial cells, a small number of cells in satellite position have features of mesenchymal cells. In this respect, human sensory ganglia differ from those of rodents and this difference may explain why no nodules of Nageotte can be found either in ageing animals or after a permanent damage to the nerve has produced considerable cell loss. Other features observed in human ganglia, but absent in rats, are multiple layers of satellite cells surrounding each neuron and desmosome-like structures between satellite cell processes. Previous studies describing maturation of the satellite-nerve cell complex in animals are confirmed. In addition, the present investigation shows that, in human ganglia, satellite cells acquire a more elaborate structure than in rodents. It is also suggested that mesenchymal cells may play a role in the trophism of nerve cells and their removal after irreversible damage.

Adolescent↗
PubMed1991

Tapia's syndrome caused by Paracoccidioidis brasiliensis.

Tapia's syndrome is due to extracranial involvement of the XIIth nerve and the recurrent laryngeal branch of the Xth nerve. There is ipsilateral paralysis of vocal cords, soft palate and tongue. The main causes are parotid and other tumors or injuries to the high neck. We describe here a Brazilian female patient who presented with a lesion in the nasal mucosa, and soon after had dysphagia and dysphonia. Examination revealed paralysis of the soft palate, vocal cords and tongue ipsilaterally. Microscopic examination of the lesion in the nasal mucosa revealed the presence of the fungus. The patient was treated with sulfonamide and ketoconasol.

Adult↗
PubMed1991

Fulminating multiple sclerosis-like leukoencephalopathy revealing human immunodeficiency virus infection.

A 66-year-old French homosexual man and a 42-year-old Brazilian man with no known risk factors for HIV infection developed headaches, asthenia, and neurologic episodes of abrupt onset. CT showed multiple hypodense, nonenhancing lesions. Serology for HIV was positive. They died respectively 2 months and 1 month after onset of the illnesses. Autopsy in both cases showed multiple, well-demarcated, demyelinating foci in the white matter of the cerebral hemispheres, brainstem, and cerebellum with histologic features characteristic of recent plaques of multiple sclerosis. There were no multinucleated giant cells or microglial nodules. Immunostaining for HIV was negative. Although a random coincidence of MS and HIV infection cannot be ruled out, the close temporal relationship between the 2 disorders suggests a possible etiologic association.

Adult↗
PubMed1991

Peripheral neuropathy in hypereosinophilic syndrome with vasculitis.

A 53-year-old woman with non-productive cough of unexplained aetiology for two years, developed a sub-acute symmetrical polyneuropathy involving all four limbs, accompanied by fever, cutaneous rash and myalgia in lower limbs. Laboratory studies revealed a leukocytosis with 70% eosinophils and excluded any cause for the hypereosinophilia. An echocardiogram showed increase in thickness of the atrial septum. Motor and sensory conduction velocity were reduced in ulnar and median nerve and unrecordable in peroneal and tibial nerves. A sural nerve biopsy showed an axonal degeneration involving myelinated and unmyelinated fibers as well as a vasculitis with fibrinoid necrosis and perivascular infiltration of eosinophils. There was considerable clinical and laboratory improvement with the use of steroids. The differential diagnosis between idiopathic hypereosinophilic syndrome and other disorders known to course with vasculitis and hypereosinophilia is discussed.

Biopsy↗
PubMed1991

[Polyneuropathy caused by ethylene oxide. Report of a case with clinical, electrophysiological and histopathological studies].

A man who worked as an operator in a factory of sterilization of heat-sensitive materials has been exposed to ethylene oxide for seven years. He developed a mild sensori-motor polyneuropathy. The electromyography and nerve condition studies showed an axonal degenerative type of neuropathy. The sural nerve biopsy revealed mild loss of myelinated fibers, some fibers with axonal degeneration, some clusters of regeneration and few rows of myelin ovoids in the teased nerve fiber preparation. This is the first report of ethylene-oxide polyneuropathy in Brazil.

Adult↗
PubMed1991

[Axonal polyneuropathy in Chagas disease].

We report the case of a 44-year-old woman presenting with chronic symmetrical, sensitive polyneuropathy on the lower limbs in the course of Chagas' disease. The electrophysiological findings were in keeping with axonal degeneration. The histological data displayed axonal degeneration with perivascular inflammatory mononuclear cells in the epineurium, with some neutrophils and eosinophils. Mononuclear cells surrounding endoneurial vessels were observed. Laboratory data did not suggest neither a mixed connective tissue disease nor a collagen vascular disorder. Hematological disease, malignancies, drug-or medicine-induced neuropathy were ruled out. The polyneuropathy in this case was probably related to Trypanosoma cruzi infection on account of the presence of high levels of anti-T. cruzi antibodies, and an immune mechanism might play a role in the vasculitic process.

Adult↗
PubMed1990

Monoclonal antibodies against sensory neuron specific antigens define the extent of neuronal abnormality in the mf mutant rat.

The mutant rat mutilated foot (mf) is affected by a sensory neuropathy which does not involve the parts of the body innervated by the thoracic cord. The possibility that sensory cells subserving clinically normal regions may be functionally spared by the mutation has been investigated by studying the expression of cell surface oligosaccharides by dorsal root ganglia (DRG) and their central processes in the spinal cord. The study included 3 lactoseries epitopes (TC6, LD2 and LA4) and the globoseries epitope SSEA3. The results show that at cervical and lumbar levels in mf rats there are reduced numbers of DRG cells reacting with the various antibodies and less immunostaining in the dorsal horns. The unexpected finding that thoracic ganglia and cord share similar appearances suggests that, in spite of being normal in number and able to produce normal amounts of substance P, thoracic DRG cells in mf rats take part in the mutation as shown by their inability to produce normal amounts of oligosaccharides and to transport them to the axon terminals.

Animals↗
PubMed1990

[Polyneuropathy caused by trichlorfon: report of a case with electrophysiologic and histopathologic study of the sural nerve].

The authors observed a patient who worked in a farm and suffered an organophosphate intoxication (trichlorfon). The immediate effect was manifested by vomiting and abdominal cramps. Three months later he presented a distal symmetric sensorimotor (predominantly motor) neuropathy with distal muscle atrophy. Electromyography has revealed denervation changes in every muscle studied and the sensory and motor nerve conduction was slowed in arms and legs. The sural nerve biopsy specimen studied by light microscopy with semi-thin section and teased fiber preparation showed axonal degeneration. The ultrastructural studies of the axonal alterations consisted of degeneration of the neurofilaments and the neurotubules with granular appearance of the axoplasm.

Aged↗
PubMed1990

[Cytomegalovirus encephalo-myelo-radiculitis in acquired immunodeficiency syndrome].

A 30 year-old male, with the acquired immune deficiency syndrome (AIDS) presented with rapidly progressive flaccid paraplegia and sphincter incontinence. Cerebrospinal fluid examination showed elevated protein and pleocytosis. Death occurred 2 months after the onset of neurological signs. Post-mortem examination showed inflammatory necrotic lesions, relatively sparing the axons and predominantly involving the roots of the cord. Numerous cytomegalovirus (CMV) inclusion bodies were found in the necrotic lesions, in the subarachnoid spaces and in Schwann cells. CMV encephalitis and involvement of the 3rd cranial nerves were also observed. Only 8 well-documented clinico-pathological cases of acute CMV myeloradiculitis, which all presented as progressive cauda equina syndrome, have been reported until now in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Chronic recurrent Guillain-Barré syndrome: report of 3 cases.

The classical Guillain-Barré syndrome is an acute or subacute polyradiculo-neuropathy whose main clinical features are progressive weakness of the limbs, decrease or absence of tendon reflexes, and sensory changes. Although in most of the cases there is complete recovery in weeks or months, some patients have a slow and progressive relapsing course and present thickening of the peripheral nerves. In this paper we describe three cases of the chronic and relapsing variety of Guillain-Barré syndrome, two of which had prominent hypertrophic changes in the peripheral nerves with onion bulb formations. The clinical and pathological features of this disease are reviewed. The three patients improved with the use of steroids.

Aged↗