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C Lacroix

Publications and source records attributed to C Lacroix.

At least 127 records · Page 7Linked to original sources
PubMed1995

Simultaneous determination of itraconazole, hydroxy-itraconazole and amphotericin B in human plasma by HPLC with photodiode array detection.

A method for the fast analysis of itraconazole, hydroxy-itraconazole and amphotericin B is described which has the advantage of speed and specificity. The method is based on methanolic extraction of the compounds from plasma, followed by reverse-phase high-performance liquid chromatography with two detection wavelengths (263 and 405 nm). The extraction step provides > or = 94% recovery and the response of the detection system is linear from 50 to 5000 ng/ml. No other drugs have been found to interfere with the assay.

Amphotericin B↗
PubMed1995

[Intramedullary glioma. Postoperative MRI aspects].

MRI is the standard exploration of intramedullary tumours. Following up the patients is of prime importance to detect and treat possible recurrences at an early stage. The purpose of this paper is to specify the postoperative MRI semiology of intraspinal gliomas. During the 1986-1992 period, 47 patients operated upon in the Bicêtre hospital for primary intraspinal tumours were followed up with high-field MR (1.5 Tesla, Signa, G.E.). The retrospective visual study was carried out by two neuro-radiologists. The patients' group consisted of 24 women and 23 men aged from 15 to 67 years (mean 38 years). The tumours treated were 29 ependymomas and 18 astrocytomas. Eighty-five MRI examinations were analysed. Most of them comprised at least two planes in T1 and T2-weighted spin echo sequences with gadolinium injection, then only T1-weighted spin echo sequences after gadolinium injection (0.1 mmol/kg). The mean postoperative follow up period in the 47 patients was 32 months (range 7 to 84 months). Contrast enhancement of the spinal cord was observed in 20 cases. In the 6 patients with recurrence (5 astrocytomas, 1 malignant ependymoma) there was a segmental increase of spinal cord volume with contrast enhancement after gadolinium injection. In 3 out of these 6 patients clinical deterioration appeared later than MRI semiology. In clinically stable patients neither enhancement nor increase in spinal cord size was found in 27 cases, and enhancement alone was noted in 12 cases. There was no reliable criterion in the analysis of post gadolinium signal enhancement that could be used to differentiate recurrence from cicatricial contrast enhancement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Simple intraparenchymal cysts of the cerebellum. Apropos of 2 cases].

INTRODUCTION: Cysts of the posterior fossa are common in the literature, but the simple cyst is rarely considered in the differential diagnosis of these cysts. METHOD: The cases of two female patients with clinical symptoms of expansive cerebellar lesion are described. These patients were explored by MRI. They were operated upon and an anatomico-pathological diagnosis was made. RESULTS: Both patients had an intraparenchymal cystic lesion of the cerebellum. No mural nodule and no enhancement after gadolinium injection were noted. The anatomico-pathological examination confirmed that the lesion was an intra-parenchymal simple cyst the walls of which showed no tumoral features. CONCLUSION: Although this anatomico-pathological entity has not previously been described in the literature, such rare diagnosis should be borne in mind in patients presenting with a cystic tumour of the posterior fossa. MRI is of paramount importance in the evaluation of these lesions, but the anatomico-pathological diagnosis is indispensable to exclude a possible tumour.

Adult↗
PubMed1995

[Solitary oligodendroglioma of the optic nerve. Apropos of a case].

Proptosis, decreased vision and oculo-motor palsies developed in the left eye of a 14-year-old girl, without neurofibromatosis signs. Computed tomographic (CT) Scans of the head and orbit showed a large fusiform expansion of the left optic nerve without intracranial involvement. Magnetic resonance imaging improved contrast resolution over CT Scanning. A neurosurgical approach was performed and the optic nerve was resected from the back of the globe to the intracranial portion. Microscopic sections demonstrated oligodendroglioma, an unusual form of optic nerve glioma.

Adolescent↗
PubMed1994

[Lesions of the spinal cord in HIV infection].

Neurological lesions are frequent complications of human immunodeficiency virus (HIV) infections. Organs involved include the brain, peripheral nerves and muscles. Since the widespread use of immunodepressive agents, spinal cord complications have also appeared although poorly documented in the literature. We observed six cases of spinal cord involvement which help indicate the modalities of practical management. In the first case, a 45-year old HIV1 + male presented dysesthesia evolving progressively over the T10 to L2 zones leading to the diagnosis of spinal cord toxoplasmosis. A gait disorder was the first sign in the second case, a 60-year old HIV1 + male. Neurological involvement progressed and the patient developed paraparesia, decreased muscular force with hypoesthesia and impaired proprioception of the lower limbs. Further complications led to coma and death and on autopsy, the patient was found to have cytomegalovirus myeloencephalitis. A 21 HIV1 + haemophiliac was our third case. Here paraplegia resulted from epidural compression due to Burkitt malignant lymphocytosis. The aggravation of paresthesia of the lower limbs, complicated by painful dysesthesia and proximal motor deficiency led to the suspected diagnosis of HIV-related myelitis in a particularly complicated case in a 52-year old seropositive male. In the fifth case, HIV infection led to major demelinization of the cervical and dorsal spinal cord due to toxoplasmosis and vacuolar myelopathy. In the sixth case, acute myelitis in an HIV2 positive male regressed spontaneously in 15 days. In clinical practice, spinal cord complications would appear to be frequent but less so than brain involvement. In the future, a better understanding of these complications should lead to specific identification of spinal cord signs in the neurological symptomatology of patients with HIV infection and allow adapted specific management.

AIDS-Related Opportunistic Infections↗
PubMed1994

Nerve biopsy findings in different patterns of proximal diabetic neuropathy.

Besides distal symmetrical sensory polyneuropathy (DSSP), middle-aged diabetic patients may present with focal or multifocal neuropathies, including proximal neuropathy of the lower limbs, the pathophysiological features of which are uncertain. We studied 10 non-insulin-dependent diabetic patients, 45 to 72 years of age, who developed a painful proximal neuropathy of the lower limbs for which other causes of neuropathy were carefully excluded. The proximal neuropathy was asymmetrical in all patients, sensory in 4, motor and sensory in the others. Signs of DSSP were present in all. A sample of the intermediate cutaneous nerve of the thigh, a sensory branch of the femoral nerve, was taken by biopsy and examined by light and electron microscopy. Examination of the nerve specimens revealed ischemic nerve lesions in 3 patients. Nerve ischemia was associated with vasculitis and inflammatory infiltration in 2 of them. In the other patients the lesions of the cutaneous nerve of the thigh included a varying incidence of axonal and demyelinative lesions similar to those observed in DSSP, with mild inflammatory infiltration in 4 of them. The density of myelinated and of unmyelinated was variably decreased. This study shows that axonal and demyelinative lesions similar to those found in diabetic DSSP are present in proximal nerves in mild forms of proximal diabetic neuropathy; while nerve ischemia, inflammatory infiltration, and vasculitis are encountered in the most severe forms of proximal diabetic neuropathy.

Aged↗
PubMed1994

Interactions between murine AIDS (MAIDS) and toxoplasmosis in co-infected mice.

We coinfected C57B1/6 mice with LP-BM5 murine leukaemia viruses, responsible for murine AIDS (MAIDS), and an avirulent strain of Toxoplasma gondii. Virus-infected mice were infected perorally on day 30 with 10 cysts of T. gondii, and T. gondii-infected mice were challenged with LP-BM5 on day 20, 30 or 60 after parasite inoculation. Uninfected and singly infected mice were used as controls. The kinetics of parasite burden in blood, lungs and brain, together with blood lymphocyte subsets, and spleen and lymph node weights, were serially determined in each group of mice. The kinetics of parasite counts in mice infected by LP-BM5 then by T. gondii were similar to those in mice infected by T. gondii only, except for lung counts, which reached higher values than in animals infected with T. gondii alone, then fell and re-increased until the end of the experiment. The only significant change in parasite burdens when mice were first infected by T. gondii and then by LP-BM5, compared with T. gondii controls, was an increase in lung counts in mice challenged with LP-BM5 20 days after T. gondii inoculation. Whatever the schedule of co-infection, the kinetics of lymphocyte subsets in co-infected mice differed from those in T. gondii- or LP-BM5-infected mice; in dually infected mice CD4+ and CD8+ cell counts were intermediate between values in mice singly infected by the parasite or the virus. Enlargement of spleen and lymph nodes, which is a major criterion of MAIDS progression, was significantly less marked in co-infected mice than in mice infected with LP-BM5 alone. These data point to cross-regulation of T. gondii and LP-BM5 infections, which results in increased susceptibility to T. gondii, and may alter the progression of MAIDS.

AIDS-Related Opportunistic Infections↗
PubMed1994

Simple method of purification and sequencing of a bacteriocin produced by Pediococcus acidilactici UL5.

A bacteriocin produced by a strain of Pediococcus acidilactici was successfully purified sequentially by acid extraction (at pH 2) and reverse-phase high-performance liquid chromatography (HPLC). Cell extracts of derivative strains deficient in bacteriocin production exhibited a similar HPLC elution profile to the active extracts except for the two peaks containing bacteriocin activity. The sequence of the antibacterial peptide consisted of 44 amino acid residues of which 42 were identified, and its molecular weight was 4624 Da, as determined by mass spectrometry. Moreover, according to the molecular weight of the peptide, the unidentified residues in the bacteriocin sequence must correspond to two tryptophan residues, confirming that the peptide isolated from Ped. acidilactici UL5 is pediocin PA-1. However, oxidized forms of the bacteriocin produced during storage also showed bacteriocin activity and resulted in a second peak with activity in the chromatograms. HPLC chromatograms of cell surface preparations from the active and from the deficient strains were confirmed by capillary electrophoresis. The purification method used is simple and effective in comparison with traditional methods, permitting a selective recovery of cell-associated bacteriocin at low pH, and its isolation in pure form for sequencing.

Amino Acid Sequence↗
PubMed1994

Immobilized cell technologies for the dairy industry.

The potential applications of immobilized cell technology (ICT) to the dairy industry are examined. Immobilization modifies the physiology of cells, and the consequences of ICT on lactose as well as citrate metabolism are reviewed. Immobilization also affects the sensitivity of lactic acid bacteria (LAB) to salt and penicillin. ICT can be used to produce starters for the dairy industry, and aspects of biomass production in beads, continuous cell release from beads, and continuous fermentations with filtration cell recycle are examined. Potential applications of ICT to the dairy industry include acidification of raw milk prior to ultrafiltration, inhibition of psychrotrophic bacteria in raw milk, yogurt production, cheese manufacture, and cream fermentations. Impacts of yeast, bacterial, or bacteriophage contaminations in ICT processes as well as their control are discussed.

Animals↗
PubMed1994

[Leptomeningeal gliomatosis. 2 clinicopathological cases].

Leptomeningeal gliomatosis is a diffuse glial infiltration of the subarachnoid space. It is primary and very rare when primary astrocytoma arises in the leptomeninges from heterotopic neuroglial tissue; it is secondary and more frequently reported when associated with a medullar or cerebral intraparenchymal astrocytoma and secondary involvement of the leptomeninges. Primary and secondary forms are difficult to differentiate before neuropathological examination. The authors report 2 anatomo-clinical cases of leptomeningeal gliomatosis in adults, with clinical courses of 6 months and 40 days respectively. The initial clinical picture was aseptic chronic or subacute meningitis. Cytologic examinations of the cerebrospinal fluid (CSF) showed moderate lymphocytosis, with elevated protein and low glucose levels, without abnormal cells. On case 2 CT scan and in case 1 spinal MRI isolated diffuse meningeal contrast enhancement was present, without intraparenchymal lesion. The neuropathological study revealed a diffuse astrocytoma glial leptomeningeal tumour with a focal involvement of the central nervous system (spinal cord in one case, temporal lobe in the other). In conclusion, an isolated aseptic lymphocytosis meningitis with meningeal abnormal signal may reveal leptomeningeal gliomatosis. Neuropathological examination can distinguish primary from secondary forms.

Arachnoid↗
PubMed1994

Metformin-associated lactic acidosis in diabetic patients with acute renal failure. A critical analysis of its pathogenesis and prognosis.

To determine the respective role of metformin accumulation and tissue hypoxia in triggering metformin-associated lactic acidosis (MALA), we measured plasma (PM) and red blood cell (RM) metformin concentrations in 14 patients with MALA and in 58 diabetic patients on well-tolerated chronic metformin treatment. In this control group RM was 0.9 +/- 0.5 mg/l. In MALA, lactic acidosis was of comparable severity whether there was significant cellular metformin accumulation (9 patients with severe renal failure) or not (5 patients with less severe renal failure). Factors of hypoxia were found in all patients except three with isolated anuria and major metformin accumulation. Early mortality was low in patients with metformin accumulation (no rapid death with the exception of two patients with end-stage hepatic failure) whereas it was high in those with metformin accumulation (4 patients died rapidly). In conclusion, MALA is not always associated with metformin accumulation. The prognosis of MALA depends mainly not upon the degree of metformin accumulation but rather upon the severity of hypoxic factors.

Acidosis, Lactic↗
PubMed1993

Monitoring of benzodiazepines (clobazam, diazepam and their main active metabolites) in human plasma by column-switching high-performance liquid chromatography.

A column-switching high-performance liquid chromatographic method for the simultaneous determination of clobazam, diazepam and their main metabolites in human plasma is described. A 200-microliters plasma sample was directly injected into a precolumn filled with TSK-gel PW. After a washing step with potassium phosphate buffer, the retained substances were backflushed into a reversed-phase column with a mobile phase of acetonitrile-phosphate buffer-diethylamine. Various drugs frequently co-administered with clobazam or diazepam do not interfere with the determination.

Anti-Anxiety Agents↗
PubMed1993

Infantile neuropathy with unstable myelin: study of the P0 protein.

An unusual form of hereditary motor and sensory neuropathy characterized by a prominent disruption of the myelin lamellae is reported. In addition to detailed morphological analysis, we investigated the protein P0, which is the major protein of peripheral myelin involved in adhesion. No major gene rearrangement and no differences in P0 protein expression were observed in the present case.

Child↗
PubMed1993

Central nervous system lesions in hypomelanosis of Ito: an MRI and pathological study.

A severe form of hypomelanosis of Ito is reported, which presented as fetal macrocephaly and neonatal epileptic encephalopathy. Lymphocyte karyotypes were normal. MRI showed an absence of delineation between cortical grey matter and white matter. The prominent neuropathological finding was an abnormal cortical morphogenesis, with the co-existence of cells migrating normally and cells exhibiting arrêt en route or even the complete absence of migration. Intense astrocytic reaction with moderate dystrophic features was present. Juxtaposition of two migration behaviours in the neural cells paralleled the cutaneous findings and reinforced the hypothesis of a genetic chimerism.

Cell Movement↗
PubMed1993

Shear stress effects on growth and activity of Lactobacillus delbrueckii subsp. bulgaricus.

Cells are frequently submitted to shear stresses during industrial processes. Shear stress can be either beneficial or detrimental to the cells depending on the organism and on the level of intensity. The present work was designed to study the effect of shear stress on cell activity of a widely used lactic acid bacterium, Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus). A constant shear stress bioreactor, based on Couette device, was developed and used to control shear stress from 0 to 72 Pa during a 4-h cultivation of a supplemented whey permeate medium with L. bulgaricus at 42 degrees C. In order to reach high shear stresses and to perform experiments within the laminar flow range where hydrodynamic conditions are accurately defined, the medium was thickened with carboxymethylcellulose (CMC). pH, cell counts, optical density, lactose and lactic acid concentrations were monitored during culture, and cell activity was evaluated after culture and after a freezing treatment at -80 degrees C, using a standardized activity test based on optical density measurement. Cell metabolism was significantly improved by intermediate shear stress levels (36 and 54 Pa) during culture. Furthermore, biomass concentration, evaluated by optical density, was clearly higher at 36 Pa. Cell lengthening was observed, which was mainly related to the presence of CMC and partly to shear stress level, especially at 36 Pa. Hydrodynamic conditions during culture could affect the membrane permeability of the cell and its resistance to freezing. Cells cultivated at 72 Pa were certainly weakened by shearing forces, and these cultures exhibited lag times twice as long after freezing as those grown at 36 Pa. Furthermore, after freezing, cultures grown at 36 Pa had shorter lag times than at 0 Pa (1.1 and 1.3 h, respectively) and higher specific growth rates (1.24 and 0.99 h-1, respectively).

Biotechnology↗
PubMed1993

Anterior spinal artery syndrome mimicking infantile spinal muscular atrophy.

A baby with acute fetal distress and severe heart malformation presented with persisting hypotonia and muscle weakness. Clinical, electromyography, and muscle biopsy findings were compatible with anterior horn cell disease. Postmortem study showed widespread ischemic necrosis in the anterior gray matter of the spinal cord. This is the first report of anterior spinal artery syndrome in a neonate.

Diagnosis, Differential↗