PubMed Health⌕ Search

Biomedical subjects

M Peoc'h

Publications and source records attributed to M Peoc'h.

At least 19 recordsLinked to original sources
PubMed1999

Elastic reinforcement and thickness of the joint capsules of the lower cervical spine.

Mechanical studies have shown the major strength of the joint capsules of the lower cervical spine, especially in its ventrolateral part. The aim of this study was to examine the structure of the joint capsules in order to discover if there is a correspondence between biomechanical properties and descriptive anatomy. Ten transverse sections and 4 sagittal sections obtained from 6 cadavers were observed under light microscopy at X 25 to X 250 magnification. Standard stains and specific elastic fiber stain were used for histologic preparation. The data were the thickness of the joint capsules in the different quadrants, and the topography and direction of the elastic fibers. The results showed that the ventrolateral part of the joint capsules is thick and reinforced by oblique elastic fibers. The dorsal part is thin. The authors suggest that the descriptive anatomy of the joint capsules confirms their mechanical properties. They note that the role of the ventrolateral part is supplemented by that of the posterior longitudinal ligament for the stability of the functional cervical spinal unit.

Aged↗
PubMed1999

Acute soman poisoning in primates neither pretreated nor receiving immediate therapy: value of gacyclidine (GK-11) in delayed medical support.

Organophosphorus (OP) nerve agents are still used as warfare and terrorism compounds. Classical delayed treatment of victims of organophosphate poisoning includes combined i.v. administration of a cholinesterase reactivator (an oxime), a muscarinic cholinergic receptor antagonist (atropine) and a benzodiazepine anticonvulsant (diazepam). The objective of this study was to evaluate, in a realistic setting, the therapeutic benefit of administration of GK-11 (gacyclidine), an antiglutamatergic compound, as a complement to the above therapy against organophosphate poisoning. Gacyclidine was injected (i.v.) in combination with atropine/diazepam/pralidoxime at man-equivalent doses after a 45- or 30-min latency period to intoxicated primates (2 LD50). The effects of gacyclidine on the animals' survival, electroencephalographic (EEG) activity, signs of toxicity, recovery after challenge and central nervous system histology were examined. The present data demonstrated that atropine/diazepam/pralidoxime alone or combined with gacyclidine did not prevent signs of soman toxicity when treatment was delayed 45 min after poisoning. Atropine/diazepam/pralidoxime also did not control seizures or prevent neuropathology in primates exhibiting severe signs of poisoning when treatment was commenced 30 min after intoxication. However, in this latter case, EEG recordings revealed that additional treatment with gacyclidine was able to stop soman-induced seizures and restore normal EEG activity. This drug also totally prevented the neuropathology observed 5 weeks after soman exposure in animals treated with atropine/diazepam/pralidoxime alone. Overall, in the case of severe OP-poisoning, gacyclidine represents a promising adjuvant therapy to the currently available polymedication to ensure optimal management of organophosphate poisoning in man. This drug is presently being evaluated in a human clinical trial for a different neuroprotective indication. However, it should always be kept in mind that, in the case of severe OP-poisoning, medical intervention must be conducted as early as possible.

Animals↗
PubMed1999

Development of an Epstein-Barr virus type 2 (EBV-2)-associated hepatic B cell non-Hodgkin's lymphoma in an HIV-1-infected patient following a change in the EBV dominant type.

From the longitudinal study of a cohort of HIV-positive patients, we report the case of a patient who initially harbored the Epstein-Barr virus (EBV) type 1 and subsequently developed an EBV-2-associated non-Hodgkin's B lymphoma a few years after an EBV-2 reactivation, or an exogenous reactivation, in the blood. At the time of diagnosis of hepatic lymphoma, the blood and the throat harbored high levels of the EBV-1 dominant strain. Sequence analysis of EBNA-2 gene revealed that: (1) type 2 EBV detected during reactivation and then in hepatic tumor was very likely to be the same strain and was mostly identical to the EBV prototype AG876; (2) type 1 virus conserved the same mutations during all the follow-up. These results suggest that EBV-2 might be associated with lymphomatogenesis and that a transient reactivation could lead to the development of an EBV-associated disease.

Genotype↗
PubMed1999

SAPHO syndrome or psoriatic arthritis? A familial case study.

OBJECTIVE: To discuss the relationships between SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome and the group of spondylarthropathies. METHODS: Few reports of familial SAPHO have been published. We describe three children, two sisters and one brother, whose clinical and radiological presentation was in accordance with SAPHO syndrome. RESULTS: Two children developed psoriasis, and one child palmoplantar pustulosis. Both sacroiliac and sternoclavicular joints were involved in these three cases. Some features in our observations are also common to psoriatic arthritis. No association was found with HLA antigens, but a history of trauma preceding the onset of symptoms was present in all three children. CONCLUSIONS: We can consider that SAPHO is nosologically related to spondylarthropathies. Psoriatic arthritis could be the missing link between SAPHO and spondylarthropathies. It is likely that both genetic and environmental factors are involved.

Acquired Hyperostosis Syndrome↗
PubMed1999

Review of the value of gacyclidine (GK-11) as adjuvant medication to conventional treatments of organophosphate poisoning: primate experiments mimicking various scenarios of military or terrorist attack by soman.

Today, organophosphorus nerve agents are still considered as potential threats in both military or terrorism situations. These agents act as potent irreversible inhibitors of acetylcholinesterase in both central and peripheral nervous systems. Conventional treatment of organophosphate poisoning includes the combined administration of a cholinesterase reactivator (an oxime), a muscarinic cholinergic receptor antagonist (atropine) and a benzodiazepine anticonvulsant (diazepam). However, numerous studies have demonstrated that the excitatory amino acid glutamate also plays a prominent role in the maintenance of organophosphate-induced seizures and in the subsequent neuropathology especially through an overactivation of the N-methyl-D-aspartate (NMDA) receptor subtype. Contrary to other non-competitive NMDA antagonists successfully tested in rodents exposed to organophosphate, gacyclidine is a novel antiNMDA compound which is in the process of approval for human use in France for neurotraumatology. This review summarizes the therapeutic value of gacyclidine as a complement to the available emergency treatment against severe organophosphate poisoning. Previous data obtained from experiments on primates in several scenarios mimicking military or terrorist attacks, using soman as the nerve agent, were used. Primates pretreated with pyridostigmine and receiving conventional emergency therapy at the first signs of poisoning survive. However, only gacyclidine is able to ensure complete management of nerve agent poisoning for rapid normalization of EEG activity, clinical recovery and neuroprotection. Gacyclidine also ensures optimal management of severe nerve agent poisoning in animals neither pretreated nor receiving emergency therapy likewise during an unexpected exposure. However, this beneficial effect is obtained provided that medical intervention is conducted rapidly after intoxication. Globally, the current lack of any other NMDA receptor antagonist suitable for human use reinforces the therapeutic value of gacyclidine as a central nervous system protective agent for the treatment of OP poisoning.

Animals↗
PubMed1998

Nerve agent poisoning in primates: antilethal, anti-epileptic and neuroprotective effects of GK-11.

Organophosphorus nerve agents are still in use today in warfare and as terrorism compounds. Classical emergency treatment of organophosphate poisoning includes the combined administration of a cholinesterase reactivator (an oxime), a muscarinic cholinergic receptor antagonist (atropine) and a benzodiazepine anticonvulsant (diazepam). However, recent experiments with primates have demonstrated that such treatment, even when administered immediately after organophosphate exposure, does not rapidly restore normal electroencephalographic (EEG) activity and fails to totally prevent neuronal brain damage. The objective of this study was to evaluate, in a realistic setting, the therapeutic benefit of administration of GK-11 (gacyclidine), an antiglutamatergic compound, as a complement to the available emergency therapy against organophosphate poisoning. GK-11 was injected at a dose of 0.1 mg/kg (i.v) after a 45-min latency period to heavily intoxicated (8 LD50) primates. Just after intoxication, man-equivalent doses of one autoinjector containing atropine/pralidoxime/diazepam were administered. The effects of GK-11 were examined on survival, EEG activity, signs of toxicity, recovery after challenge and central nervous system histology. The present data demonstrate that treatment with GK-11 prevents the mortality observed after early administration of classical emergency medication alone. EEG recordings and clinical observations also revealed that GK-11 prevented soman-induced seizures and motor convulsions. EEG analysis within the classical frequency bands (beta, theta, alpha, delta) demonstrated that central activity was totally restored to normal after GK-11 treatment, but remained profoundly altered in animals receiving atropine/pralidoxime/diazepam alone. GK-11 also markedly accelerated clinical recovery of soman-challenged primates. Lastly, this drug totally prevented the neuropathology observed 3 weeks after soman exposure in animals treated with classical emergency treatment alone. GK-11 represents a promising adjuvant therapy to the currently available emergency polymedication to ensure optimal management of organophosphate poisoning in man. This drug is presently being evaluated in a human clinical trial for a different neuroprotective indication.

Animals↗
PubMed1998

[Cytology of fluids of articular puncture].

Cytologic examination of synovial fluid has been shown to be useful in the diagnosis of various joint diseases. Few pathologists are proficient in the interpretation of the occasional synovial fluids that most cytology laboratories receive. The majority of the aspirated synovial fluids are sent only for bacterial culture and valuable information from the cytologic examination is missed. We describe how pathologists should perform analysis of these fluids and what kind of information they can provide to the physician.

Cytodiagnosis↗
PubMed1997

[Primary bone leiomyosarcoma. Anatomo-clinical case with immunohistochemistry study and review of the literature].

We describe a primary leiomyosarcoma arising in the proximal part of the right tibia of a 38-year-old man. The diagnosis was confirmed by immunohistochemistry (positivity of tumor cells for alpha smooth muscle actin, HHF 35, desmin and vimentin). To the best of our knowledge, this is the 49th documented case of primary leiomyosarcoma of bone outside the facial skeleton. This exceptional tumor arises more commonly in adults (mean age: 53 years) and in the long bones of lower limbs, near the knee. The most frequent symptom is pain with or without swelling or fracture. Radiological findings invariably consist of a non specific osteolytic lesion. Although their histological appearance does not differ from that of extraosseous leiomyosarcomas, their diagnosis is difficult and often requires immunohistochemical and/or ultrastructural study. From a practical point of view, the diagnosis of primary leiomyosarcoma of bone also requires an intensive review of the case history and of previous pathology. This is necessary in order to eliminate an extraosseous primary site (mainly in uterus, gastrointestinal tract and soft tissues). As well as clinicopathological features, modes of treatment and results are also reviewed.

Adult↗
PubMed1997

GK 11: promising additional neuroprotective therapy for organophosphate poisoning.

Recent experiments with primates have demonstrated that treatment with atropine/pralidoxime/diazepam, even if administered immediately after organophosphate exposure, does not totally prevent neuronal brain damage. Using primates, we have studied, for the first time, the ability of GK-11 (gacyclidine), an antiglutamatergic drug in the process of agreement for human use, given as an additional therapy, to counteract the neuropathology due to organophosphate exposure that persists after classical treatment with oxime/atropine/benzodiazepine. We have also examined the recovery of the organophosphate-intoxicated primates. Male Cynomolgus monkeys were pretreated 1 hour before poisoning with pyridostigmine, then intoxicated with 8 LD50 of soman and immediately treated with the combination pralidoxime/atropine/diazepam. Some of the animals also received GK-11 at 0.01; 0.03 or 0.1 mg/kg (i.v.) 10 minutes after soman challenge. Recovery of the primates (reflexes, movements, feeding) and the neuropathological changes that occurred three weeks after intoxication (histological examinations and neuronal cell density measurement) were compared in GK-11-treated and control animals. At all doses tested, GK-11 prevented the neuronal rarefaction of the frontoparietal cortex that was observed in soman-intoxicated animals that received only oxime/atropine/diazepam. Moreover, the 0.01 mg/kg dose of GK-11 improved the early recovery of intoxicated primates from 1 day after intoxication. In the view of the most effective management of organophosphate intoxication that is currently available, GK-11 thus appears to be a promising additional neuroprotective therapy. This drug is presently being evaluated in a human clinical trial for a different neuroprotective indication.

Animals↗
PubMed1996

[Neuropathologic data in drug-resistant partial epilepsy. Report of a series of 195 cases].

This report concerns the histopathological findings in 195 consecutive surgical specimens of patients with chronic drug-resistant epilepsy. Six pathological groups were identified corresponding to 63 tumors, 51 developmental lesions, 39 Ammon's horn sclerosis, 27 non specific changes, 11 glial or gliomesodermal scars and 4 Rasmussen's encephalitis. In 14 patients, 2 distinct abnormalities were observed with Ammon's horn sclerosis as one part of the dual pathology. All tumors were of low histopathological grade and included 30 dysembryoplastic neuroepithelial tumors, 17 gangliogliomas, 5 subependymal giant cell astrocytomas of tuberous sclerosis, 4 pleomorphic xanthoastrocytomas, 3 astroblastomas, 3 astrocytomas and 1 oligodendroglioma. Developmental lesions included 22 hamartomas, 12 focal dysplasias, 5 microdysgenesis, 1 nodular cortical heterotopia, 1 arachnoid cyst and 10 cavernomas. These findings emphasize two pathological features. Firstly, well-defined changes were present in all specimens. Secondly, the most common lesions were respectively tumors and developmental abnormalities.

Adolescent↗
PubMed1996

[Systemic granulomatous reaction in hip prosthesis. Apropos of 2 anatomoclinical cases].

PURPOSE OF THE STUDY: The production of particulate wear debris is a recognised complication of joint arthroplasty. Focus was made on local tissue reactions. Systemic distribution of wear debris are less know. We report two new cases of distant granulomatous reaction. MATERIAL: The first case concerned a 71-year-old man with lymph node histiocytosis incidentally discovered during the staging of a prostatic carcinoma. The second case concerned a 61-year-old man with a visceral granulomatosis reaction (liver, spleen and lymph node) associated to hepatic ans splenic enlargement. METHODS: We realised an histological analysis of several tissue specimens for these two patients and for one case an inductively coupled plasma-mass spectrometry technique (ICPMS). RESULTS: In all specimens we identified a foreign body granulomatous reaction characterized by the presence of particles coming from hip arthroplasty. The ICPMS identified titanium in spleen. DISCUSSION: Distant granulomatous reaction are generally localised in regional lymph nodes and discovered by accident. A systemic granulomatous reaction attributable to wear particles raises the question of long term biocompatibility of prosthetic materials. CONCLUSION: Besides local reaction, it is of utmost importance that physicians involved in prosthetic field take into consideration the possible systemic adverse effect of wear particles from arthroplasty.

Aged↗