Search PubMed⌕ Search

Biomedical subjects

F Scaravilli

Publications and source records attributed to F Scaravilli.

At least 127 records · Page 7Linked to original sources

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↗

Strongyloides stercoralis hyperinfection in an HIV positive patient.

A 25 year old British man of previous good health presented with persistent generalised lymphadenopathy and was found to be human immunodeficiency virus (HIV) antibody positive. Three years later after weight loss and loose stools Strongyloides stercoralis was identified in the latter and successfully treated with thiabendazole. Shortly afterwards, a further episode again responded rapidly, but was swiftly followed by a final and fatal illness with severe debility and metabolic imbalance unresponsive to all treatment. Necropsy showed widespread and heavy strongyloidiasis with pulmonary haemorrhage, bronchopneumonia, and meningitis.

Adult↗

Destructive lesions in demyelinating disease.

Three cases are presented in which clinical and radiological features suggested the diagnosis of glioma but surgical biopsy revealed a demyelinating process, with tissue destruction and cyst formation in two. One patient had clinically definite multiple sclerosis. Two had probable acute disseminated encephalomyelitis. Treatment with high dose steroids is appropriate when there is clinical or investigative evidence to suggest the presence of demyelinating disease, before deciding on biopsy.

Adolescent↗

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↗

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↗

Studies of vasoactive intestinal polypeptide expression in injured peripheral neurons using capsaicin, sympathectomy and mf mutant rats.

The increased expression of vasoactive intestinal polypeptide (VIP) in injured peripheral neurons was studied. In contrast to substance P, there was a marked increase, and maintained fast axonal transport, of VIP in rat sciatic nerve after peripheral axotomy. Local capsaicin application to the nerve trunk failed to inhibit the injury-induced VIP increase, and capsaicin even increased VIP levels when applied locally to uninjured nerves. Pharmacological sympathectomy showed that some of the peripheral VIP increase may occur in post-ganglionic sympathetic fibres. The VIP increase after injury appeared unaffected in the mf mutant rat, in spite of its loss of lumbar dorsal root ganglion cells. VIP-staining fibres in the epi- and peri-neurium and perivascular plexuses of sciatic nerve showed an increase in number in parallel with the changes of the nerve VIP content. These findings suggest that sensory and sympathetic nerve fibres expressing VIP after injury play a role in the regulation of blood flow to nerves, and in the pathophysiological processes in nerve and dorsal spinal cord which follow peripheral nerve injury.

Animals↗

Movement disorders in mitochondrial myopathies. A study of nine cases with two autopsy studies.

Of 85 consecutive patients with mitochondrial myopathy, 29 had clinically significant central nervous system involvement. Nine of these had movement disorders that included dystonia, chorea, parkinsonism, and myoclonus. Autopsy studies of one patient with ataxia, dementia, and parkinsonism followed by dystonia showed the features of olivopontocerebellar atrophy with additional degenerative changes in the basal ganglia. Postmortem in a further case with myoclonus, deafness, muscle weakness, retinopathy, and ataxia showed symmetrical mineralisation of the striatopallidodentatal system.

Adult↗

Neurofibromatous neuropathy.

Three cases of chronic distal sensorimotor neuropathy are described in patients with neurofibromatosis. One had type 2 or central neurofibromatosis with a chromosome 22 deletion; the precise form of the disease was not established in the other two. A striking clinical feature was a diffuse nodular enlargement of the peripheral nerves. Nerve biopsies from all three cases demonstrated the presence of neurofibromatous pathology. Neurofibromatous neuropathy constitutes a rare manifestation of neurofibromatosis, related to diffuse neurofibromatous changes in the peripheral nerves.

Adult↗

The involvement of the cerebral cortex in human immunodeficiency virus encephalopathy: a morphological and immunohistochemical study.

The encephalopathy resulting from direct infection of the brain by human immunodeficiency virus (HIV), which correlates clinically with the AIDS dementia complex, has been reported as being localized to the white matter where it induces myelin loss, gliosis and perivascular infiltration by mononuclear macrophages and multinucleated giant cells. Damage to the cortical grey matter in HIV encephalopathy was investigated in nine randomly selected HIV-positive cases with or without clinical or morphological evidence of encephalopathy and in five age-matched controls, using routine histology and immunohistochemical methods [glial fibrillary acidic protein (GFAP), microglia and HIV antibodies]. Increased numbers of GFAP-expressing astrocytes and Ricinus communis agglutinin 1-120-expressing microglial cells were found in all the HIV-positive cases (including asymptomatic) and their severity could be correlated with the severity of the encephalopathy in the white matter; the increase in number of cells expressing GFAP was diffuse and the intensity of the staining higher than that of microglial cells. The subpial region was the most severely involved. It is suggested that involvement of the cortical grey matter is more common in HIV infection than previously suspected and that clinical evidence of a dementing process in AIDS is not necessarily due only to white matter lesions.

AIDS Dementia Complex↗

Cytomegalovirus (CMV) encephalomyeloradiculitis and human immunodeficiency virus (HIV) encephalitis: presence of HIV and CMV co-infected multinucleated giant cells.

A 25-year-old homosexual male with AIDS presented with a cauda equina syndrome clinically suggestive of cytomegalovirus (CMV) myeloradiculitis. He was treated with ganciclovir with transient improvement of neurological signs and died 4 months after onset of neurological signs. Neuropathological examination revealed human immunodeficiency virus (HIV) encephalitis, CMV subependymal encephalitis and CMV myeloradiculitis. The latter was characterised by myelin loss, Schwann cell proliferation and presence of CMV early antigens in the nuclei of S-100 protein-positive cells in the spinal roots. In the subependymal regions, morphologically characteristic multinucleated giant cells, positive for CD68, contained early CMV antigens (E13) in their nuclei and HIV antigens (gp41 and p24) in their cytoplasm. The observation that HIV and CMV can co-infect the same cell in vivo raises the possibility of a direct synergistic interaction of both viruses at cell level. This suggests that CMV may play a role as a co-factor in the pathogenesis of HIV encephalopathy.

Acquired Immunodeficiency Syndrome↗

Cytomegalovirus encephalopathy in an infant with congenital acquired immuno-deficiency syndrome.

A female infant born pre-term to a HIV seropositive mother presented at birth with seropositivity for HIV and CMV viruria. At five months of age she developed an AIDS-related complex. Six months later she died from rapidly progressive diffuse encephalopathy. Post mortem examination revealed generalized CMV infection. Neuropathological examination showed a nodular encephalitis with occasional cytomegalic cells containing characteristic CMV inclusion bodies. There was no evidence of HIV encephalitis; immunostaining for HIV antigen (gp 41) was negative. Opportunistic infections in infants with congenital AIDS are the exception. To our knowledge, only one case of CMV encephalitis in an infant with congenital AIDS has been reported previously. In that case, as in the present one, a reactivation of a congenital CMV infection is likely.

AIDS-Related Complex↗

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↗