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Biomedical subjects

A Vital

Publications and source records attributed to A Vital.

At least 109 records · Page 6Linked to original sources
PubMed1985

Polyarteritis nodosa and peripheral neuropathy. Ultrastructural study of 13 cases.

Peripheral nerves from 13 patients suffering from polyarteritis nodosa with multiple mononeuropathy were studied by light and electron microscopy. In the majority of cases, the vascular lesions were associated with Wallerian-like degeneration. Myelinated fibers presenting a normal axon with a disproportionately thin myelin sheath were less numerous. Unusual abnormalities consisted of swollen axons with an accumulation of organelles. Unmyelinated fibers were also damaged. A quantitative estimation of myelinated fibers loss did not show any selective vulnerability of either the large or the small diameter group.

Adult↗
PubMed1985

[Tomaculous neuropathy. Electrophysiologic study].

In two cases with recurrent palsies, the results of electrophysiological studies led to nerve biopsy showing typical tomacula. The first case was an inherited neuropathy with liability to pressure palsies. The second case was an apparently sporadic painless recurrent brachial neuropathy. Electrophysiological alterations were diffuse and sensory fibres of the median nerve between index and wrist were the most involved. Conduction blocks were observed without palsy in narrow anatomical passageways where nerve compressions are frequent (ulnar nerve at the elbow, peroneal nerve at the fibula). A compression by a neighbouring anatomical structure could make the prognosis worse and justify nerve decompression. The nerves with slowest conduction have the most important risk of palsy and the patients should be given advice to avoid their compression.

Adolescent↗
PubMed1985

[Hypermyelination in a case of peripheral neuropathy with benign IgM monoclonal gammopathy].

A 65 year-old man presented with a 8 months history of ataxia and weakness of the lower limbs. Acroparesthesias had been present for ten years in all four limbs. Serum protein electrophoresis showed a monoclonal IgM kappa spike. Bone marrow showed no increase in plasma cells. Motor conduction velocities were reduced. A biopsy from the right superficial peroneal nerve revealed several enlarged myelin sheaths in each fascicle on semi-thin sections. Under electron microscopy these large myelin sheaths were either regularly arrayed around the axon or formed several large additional loops. The outer lamellae of these abnormal myelin sheaths and of the additional loops were frequently widened. Other fibers showed a widening of some myelin lamellae (W.M.L.) with a myelin sheath of varying thickness, and these widened lamellae were frequently joined together. A direct immunopathological study could not be made. The widening of some myelin lamellae is present in most cases of peripheral neuropathy with IgM monoclonal gammopathy and a fixation of anti IgM serum on some myelin sheaths may be demonstrated by direct immunopathology. Hypermyelination has been reported in a few cases. In this patient hypermyelination was as developed as in typical cases of tomaculous neuropathy. An association in some myelin sheaths of hypermyelination and W.M.L. has been noted in serum induced myelin aberrations in peripheral nervous system cultures.

Aged↗
PubMed1985

[Cerebral lesions in a case of Degos' disease].

The central nervous system may be involved in Degos disease, but neuropathologic observations are still few. We report a typical case with cerebral involvement. The diagnosis was suggested by the characteristic skin lesions and vascular damage. In the central nervous system, occlusive changes of small arteries were responsible for areas of ischaemic necrosis. These foci of infarction were of varying size, age and distribution. Intestinal lesions were discrete and death was due to several cerebral infarcts.

Adult↗
PubMed1985

[Peritoneal gliomatosis associated with a mature teratoma of the ovary].

Peritoneal or/and omental implants composed of mature glial tissue is a rare complication of ovarian teratomas. A few cases have been previously reported, and one more case is described. The glial nature of the implants is proved by the presence of glial fibrillary acidic protein. The previous reports of long survival indicate that occurrence of this peritoneal gliomatosis does not alter the prognosis and that therapy directed at the peritoneal implants of mature glia is not required for cure.

Child↗
PubMed1984

Amyloid neuropathy: relationship between amyloid fibrils and macrophages.

A case of amyloid neuropathy associated with a multiple myeloma IgG light chain is reported. Under light microscopy the peripheral nerve exhibited several amyloid deposits. Electron microscopy revealed numerous amyloid deposits; at their periphery, macrophagic histiocytes were observed, containing a few tufts of parallel fibrils in their cytoplasm. A few plasma cells were scattered in the endoneurium and did not exhibit such a relationship. These findings resemble those recently observed in stem-cell cultures of IgG lambda chain human myeloma.

Amyloid↗
PubMed1983

Ultrastructural study of peripheral nerve in arteritic diabetic patients.

The peripheral nerve was taken from 25 diabetic patients with arteritis just before or after amputation of a leg. The ultrastructural study of myelinated fibers showed several alterations. Loss of fibers varied greatly from case to case. This was accompanied in some cases by hypertrophy of the Schwann cells around demyelinated fibers as has been observed in some ordinary diabetic neuropathies. Unusual abnormalities consisted of particular axonal degeneration and evidence of aberrant remyelination. This axonal injury was peculiar because of the accumulation of organelles which tended to transform some of the fibers into enlarged axons. Such a lesion might correspond to a hypoxic axonopathy.

Aged↗
PubMed1983

[Recurrent cerebral hemorrhage and amyloid angiopathy].

A patient with no previous relevant history presented with recurrent cerebral hemorrhages of which he died 4 years 5 months after the onset. On autopsy, an amyloid angiopathy was present and localised to the cerebrovascular system. Hemorrhages were associated with some small infarcts in the subcortical regions. The leptomeninges and the cortical arteries were mostly involved by an infiltration mainly in the adventitia and media. There were no senile plaques in the cortex. The amyloid deposit present in the senile plaques and in the vessel walls of the amyloid angiopathy could be the result of two distinct pathological processes.

Amyloidosis↗
PubMed1982

Bile canaliculi morphology after bile duct ligation in the rat with portacaval shunt: a time course study.

Besides the spontaneous occurrence of portacaval shunts in chronic liver diseases and the performance of shunt to cure portal hypertension, shunts are now proposed for the treatment of some metabolic diseases, especially in children. The portacaval shunt model in the rat, known to induce liver atrophy related to hepatocyte loss and atrophy, was used to investigate morphological liver changes occurring in cholestasis. Two weeks after portacaval or sham portacaval shunt, the bile duct was ligated and livers were examined by light and electron microscopy at 5 h, 20 h, 4 days and 8 days. Portal inflammatory reaction and proliferation of bile ducts were identical but areas of patchy hepatic necrosis were more numerous in shunted rats. Hepatocyte size decreased in the sham group but increased in the other group. Hepatocyte ultrastructural changes were similar in the two groups. At 5 h, the number of bile canaliculi sections increased (X2) and 95% of them were normal. As time elapsed, the ratio of dilated bile canaliculi without microvilli and of bile canaliculi filled with cytoplasmic blebs increased but in no case reached 50% of the total. These results show that in the rat, cholestasis induced by bile duct ligation has approximately the same characteristics in control or shunted animals.

Animals↗
PubMed1982

Morphologic structure of bile canaliculi after bile duct ligation in the rat. A time-course study.

Changes in bile canaliculi (BCs) after bile duct ligation (BDL) are heterogeneous throughout the liver lobule. Male Wistar rats were killed five hours, 20 hours, four days, or eight days after BDL, and BCs were counted according to their shape (1, normal; 2, elongated with microvilli; 3, dilated, devoid of microvilli; or 4, filled with blebs). Compared with controls, the number of BCs doubled after BDL, less than 10% of the BCs were of type 3. As time elapsed, the ratios of types 3 and 4 increased; however, their combined ratio always was below 50%, and remained stable between days 4 and 8. Bilirubin levels peaked between days 2 and 4, then remained stable. The heterogeneous changes in BCs could be explained by the heterogeneous tightness of tight junctions. Decrease in cell size and increase in the size of BC branches could favor contact between bile and blood.

Aged↗
PubMed1979

A spin label study of myelin fluidity with normal and pathological peripheral nerves.

The myelin fluidity in peripheral nerves from normal subjects and patients with neuropathy has been studied. Nerve biopsies were made in subjects without neuropathy and in patients with Guillain-Barré, alcoholic or diabetic polyneuropathies and heredodegenerative diseases. The fluidity was studied using a stearic acid spin label with a nitroxide radical at C12 (12-doxylstearic acid) which was introduced by exchange between spin label-charged BSA and nerve myelin. Spectra was obtained with a VARIAN E 109 ESR spectrometer, at temperatures from 5 to 45 degrees C. The ultrastructure of biopsied nerves was also studied. The electron spin resonance (ESR) spectra were all typical of a partially immobilized nitroxide with a distance between outer hyperfine lines (2T//) of about 50 G, at room temperature. The curve 2T// against temperature shows two critical temperatures: 10 and 30 degrees C for all nerves. No correlation could be established between ultrastructure and fluidity of nerves. However, the myelin of nerves from diabetic patients showed a significant increase in viscosity. This physicochemical modification may represent an initial alteration of the myelin sheath, and demands further investigation. No modification of the myelin fluidity was observed in any of the other nerves studied.

Adolescent↗
PubMedDate not supplied

Merrf family with 8344 mutation in tRNA (lys). Evidence of a mitochondrial vasculopathy in muscle biopsies.

This article reports a new MERRF family. The mother, regarded as suffering from Ramsay-Hunt Syndrome, and her three daughters, had the same clinical pattern: myoclonic epilepsy and ataxia. Two daughters were studied on morphological, biochemical and molecular genetic levels. Muscle biopsies showed ragged-red fibres and mitochondrial vasculopathy. Arterioles were strongly SDH-reactive and COX-negative. By electron microscopy, abnormal mitochondria were observed in skeletal muscle fibres, in smooth muscle fibres of intramuscular vessels and in sweat gland epithelium. The study of the respiratory chain showed complex IV and I + IV deficiency, respectively. Mitochondrial tRNA (lys) mutation at position 8344 was pointed out as previously reported in the MERRF syndrome.

Adolescent↗
PubMedDate not supplied

Chronic inflammatory demyelinating polyneuropathy: immunopathological and ultrastructural study of peripheral nerve biopsy in 42 cases.

The authors recently reexamined the peripheral nerve biopsies from 42 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). There were 27 males and 15 females, aged from 9 to 84 years, and 13 had relapses. No patient had vasculitis, monoclonal gammopathy, tumor, diabetes mellitus, Lyme disease, familial neuropathy, HIV, or any other immune deficiency. In the endoneurium, perivascular inflammatory cell infiltrates were present in only one case, but scattered histiocytes marked by KP1 on paraffin-embedded fragments were present in every case and there were no T-lymphocytes. At ultrastructural examination macrophage-associated demyelination was observed in 17 cases, of which 6 had relapses separated by intervals of several months or years. Axonal lesions without associated primary demyelination were observed in 4 cases and 3 of these had relapses. Thirty-two patients had mixed lesions of demyelination and axonal involvement. This study confirms other recent data indicating that in all cases of CIDP, macrophages are present in the endoneurium. Macrophage-associated demyelination is the characteristic feature of demyelinating forms. On the other hand, isolated primary axonal forms, which have been known since 1989, are relatively frequent and prone to relapses.

Adolescent↗
PubMedDate not supplied

Inflammatory demyelinating neuropathy in C57BL/KaLwRij mice.

Neuropathies associated with monoclonal gammopathy (MG) in humans have been extensively studied in the past few years, but experimental models have proved difficult to create. C57BL mice are prone to develop benign MG and it has been reported that some of these mice with benign IgG MG present an inflammatory demyelinating neuropathy (IDN). In order to verify such findings, the serum and the sciatic nerve of the first group of 28 C57BL/KaLwRij mice were examined: none of 10 mice with normal serum showed ultrastructural abnormalities in the sciatic nerve, while lesions of IDN were present in three out of 10 mice with benign IgG MD, in two out of seven with benign IgM MG, and in a mouse with Waldenström-like lymphoma. The second group of animals was studied in the same way; it was composed of seven C57BL mice with transplanted multiple myeloma, and six C57BL mice with Morbus Waldenström-like lymphoma. In none of these animals, which were younger than those of the first group, was any lesion of IDN observed.

Animals↗
PubMedDate not supplied

Adult dementia due to intraneuronal accumulation of ceroidlipofuscinosis (Kufs' disease): ultrastructural study of two cases.

Two cases, a man and a woman, presented the initial signs of progressive dementia at about age 40 years. Aphasia, facial dyskinesias, and ataxia were associated with behavioral disturbances in the first patient. Aphasia, oculomotor disturbances, and ataxia coexisted with dementia in the second patient. In both cases, ultrastructural examination of a cerebral biopsy showed intraneuronal granular osmiophilic deposits mixed with lamellar structures and fingerprint profiles. Such deposits are characteristic of Kufs' disease. In the first patient, brain autopsy was performed 3 years after cerebral biopsy. Our two cases presenting dementia with motor disturbances correspond to type B Kufs' disease.

Adult↗