Search PubMed⌕ Search

Biomedical subjects

J Mancini

Publications and source records attributed to J Mancini.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Lamotrigine therapy in children. Retrospective study of 32 children].

BACKGROUND: Lamotrigine is one of the new anti-epileptic drugs, which is a phenyltriazine derivative. It is considered to act via an inhibitory effect on voltage-sensitive sodium channels and to have no GABAergic action. PATIENTS AND METHOD: We studied its efficiency in 32 children with refractory epilepsy after a treatment of at least one year with other anti-epileptic drugs. We then compared our results with other publications. RESULTS: Good efficiency (at least 50% reduction of crises) has been demonstrated for lamotrigine in children with generalized epilepsy (62.5% good results), particularly with absence epilepsy and Lennox-Gastaut syndrome. Results are encouraging for our few patients with epilepsy with continuous spike waves during slow-wave sleep. On the other hand, more precise indications are needed in partial epilepsy. CONCLUSION: Seizure control was generally maintained during one year of lamotrigine treatment. Association to sodium valproate is relevant for most of the authors. Adverse effects are uncommon, and we did not observe any skin rash. Lastly, improvement of behaviour and cognitive functions represents another important benefit of lamotrigine.

Adolescent↗
PubMed2000

Membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG). A widespread protein superfamily.

The members of the MAPEG superfamily have been aligned and found to be distantly related, with a common pattern of hydropathy. Figure 2A shows the multiple sequence alignments of the human members and Figure 2B the corresponding superimposed hydropathy profiles. The alignment in Figure 2A demonstrates a total of six strictly conserved residues. The Arg-51 in LTC4 synthase has been suggested to function as proton donor for the opening of the LTA4 epoxide. This arginine is found in all but the FLAP sequences in accordance with the observation that FLAP has no known enzyme activity. Also the Tyr-93 in LTC4 synthase has been suggested to function as a base for the formation of the thiolate anion of glutathione. This tyrosine is not conserved in MGST1 or MGST1-L1. Table 1 summarizes some other properties of the individual human proteins. They are all of the same size, ranging from 147 to 161 amino acids. Only FLAP differs in that its isoelectric point is more neutral than that of the other, more basic proteins. The genes encoding these proteins all reside on different chromosomes (when known) (Table 1). In addition to the human proteins, MAPEG members have been identified in plants, fungi, and bacteria. It is clearly a challenge to elucidate their role in these different phyla in relation to their defined physiological functions in humans.

Amino Acid Sequence↗
PubMed1999

[Cognitive and socio-educational ramifications of epilepsy in the child].

Cognitive effects and psychosocial risks after childhood onset epilepsy are better known nowadays, as well as their dependency upon several causative factors. Remission of seizures does not ensure good psychosocial outcome. A specific prevention and evaluation work is always necessary, and is first a medical work. Information has a very important part. Restrictions have to be optimally adapted to seizure related risk, in order to obtain an improvement in quality of life. Neuropsychological assessments and psychopathological approach are both necessary. Neuropsychological assessment may show specific cognitive impairments related to epilepsy type and localisation or epileptic syndrome. Rehabilitation has to be suited to each child, taken into account his intellectual development as well as his behavior and relationships. Multidisciplinary teams working in coordination to teachers are an important need.

Child↗
PubMed1999

Configural and local processing of faces in children with Williams syndrome.

Three experiments investigated face processing in children with Williams syndrome (WS). In Experiment 1, the ability to discriminate different aspects of faces was compared between WS subjects and a group of children individually matched for chronological age (CA-matches) and another group matched for mental age (MA-matches). In Experiments 2 and 3, the ability to process the local and configural aspects of geometrical patterns and faces was assessed within the same groups of subjects. The results indicated that the WSs' overall performance on face recognition was below that of the CA-matches, but similar to that of the MA-matches. This study revealed in addition that the CA- and MA-matches showed a bias toward a configural mode of face and geometrical shape processing, whereas children with WS did not show any bias. These findings suggest that face processing undergoes an abnormal developmental course in WS.

Adolescent↗
PubMed1999

Identification of a mutation cluster in mevalonate kinase deficiency, including a new mutation in a patient of Mennonite ancestry.

Mevalonate kinase (MKase) deficiency (MKD) is a rare autosomal recessive disorder in the pathway of cholesterol and nonsterol isoprenoid biosynthesis. Thus far, two disease-causing missense alleles have been identified, N301T and A334T. We report four additional mutations associated with MKD: L264F, T243I, L265P, and I268T, the last found in a patient of Mennonite ancestry. Electrophoretic analysis of bacterially expressed wild-type and mutant MKase indicated that I268T and T243I mutants produced normal or somewhat reduced amounts of MKase protein; conversely, L264F and L265P mutations resulted in considerably decreased, or absent, MKase protein. Immunoblot analysis of MKase from all patients suggested that the MKase polypeptide was grossly intact and produced in amounts comparable to control levels. Three mutations resulted in significantly diminished MKase enzyme activity (<2%), whereas the I268T allele yielded approximately 20% residual enzyme activity. Our results should allow more-accurate identification of carriers and indicate a mutation "cluster" within amino acids 240-270 of the mature MKase polypeptide.

Alleles↗
PubMed1999

Common structural features of MAPEG -- a widespread superfamily of membrane associated proteins with highly divergent functions in eicosanoid and glutathione metabolism.

A novel superfamily designated MAPEG (Membrane Associated Proteins in Eicosanoid and Glutathione metabolism), including members of widespread origin with diversified biological functions is defined according to enzymatic activities, sequence motifs, and structural properties. Two of the members are crucial for leukotriene biosynthesis, and three are cytoprotective exhibiting glutathione S-transferase and peroxidase activities. Expression of the most recently recognized member is strongly induced by p53, and may therefore play a role in apoptosis or cancer development. In spite of the different biological functions, all six proteins demonstrate common structural characteristics typical of membrane proteins. In addition, homologues are identified in plants, fungi, and bacteria, demonstrating this superfamily to be generally occurring.

Amino Acid Sequence↗
PubMed1999

Rofecoxib [Vioxx, MK-0966; 4-(4'-methylsulfonylphenyl)-3-phenyl-2-(5H)-furanone]: a potent and orally active cyclooxygenase-2 inhibitor. Pharmacological and biochemical profiles.

The discoveries that cyclooxygenase (COX)-2 is an inducible form of COX involved in inflammation and that COX-1 is the major isoform responsible for the production of prostaglandins (PGs) in the gastrointestinal tract have provided a rationale for the development of specific COX-2 inhibitors as a new class of anti-inflammatory agents with improved gastrointestinal tolerability. In the present study, the preclinical pharmacological and biochemical profiles of rofecoxib [Vioxx, also known as MK-0966, 4-(4'-methylsulfonylphenyl)-3-phenyl-2-(5H)-furanone], an orally active COX-2 inhibitor, are described. Rofecoxib is a potent inhibitor of the COX-2-dependent production of PGE(2) in human osteosarcoma cells (IC(50) = 26 +/- 10 nM) and Chinese hamster ovary cells expressing human COX-2 (IC(50) = 18 +/- 7 nM) with a 1000-fold selectivity for the inhibition of COX-2 compared with the inhibition of COX-1 activity (IC(50) > 50 microM in U937 cells and IC(50) > 15 microM in Chinese hamster ovary cells expressing human COX-1). Rofecoxib is a time-dependent inhibitor of purified human recombinant COX-2 (IC(50) = 0.34 microM) but caused inhibition of purified human COX-1 in a non-time-dependent manner that could only be observed at a very low substrate concentration (IC(50) = 26 microM at 0.1 microM arachidonic acid concentration). In an in vitro human whole blood assay, rofecoxib selectively inhibited lipopolysaccharide-induced, COX-2-derived PGE(2) synthesis with an IC(50) value of 0.53 +/- 0.02 microM compared with an IC(50) value of 18.8 +/- 0.9 microM for the inhibition of COX-1-derived thromboxane B(2) synthesis after blood coagulation. Using the ratio of the COX-1 IC(50) values over the COX-2 IC(50) values in the human whole blood assay, selectivity ratios for the inhibition of COX-2 of 36, 6.6, 2, 3, and 0.4 were obtained for rofecoxib, celecoxib, meloxicam, diclofenac, and indomethacin, respectively. In several in vivo rodent models, rofecoxib is a potent inhibitor of carrageenan-induced paw edema (ID(50) = 1.5 mg/kg), carrageenan-induced paw hyperalgesia (ID(50) = 1.0 mg/kg), lipopolysaccharide-induced pyresis (ID(50) = 0.24 mg/kg), and adjuvant-induced arthritis (ID(50) = 0.74 mg/kg/day). Rofecoxib also has a protective effect on adjuvant-induced destruction of cartilage and bone structures in rats. In a (51)Cr excretion assay for detection of gastrointestinal integrity in either rats or squirrel monkeys, rofecoxib has no effect at doses up to 200 mg/kg/day for 5 days. Rofecoxib is a novel COX-2 inhibitor with a biochemical and pharmacological profile clearly distinct from that of current nonsteroidal anti-inflammatory drugs and represents a new therapeutic class of anti-inflammatory agents for the treatment of the symptoms of osteoarthritis and rheumatoid arthritis with improved gastrointestinal tolerability.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1999

Angelman syndrome resulting from UBE3A mutations in 14 patients from eight families: clinical manifestations and genetic counselling.

Angelman syndrome (AS) is a neurological disorder with a heterogeneous genetic aetiology. It most frequently results from a de novo interstitial deletion in the 15q11-q13 region, but in a few cases it is caused by paternal uniparental disomy (UPD) or an imprinting mutation. The remaining 20 to 30% of AS patients exhibit biparental inheritance and a normal pattern of allelic methylation in the 15q11-q13 region. In this latter group, mutations in the UBE3A gene have recently been shown to be a cause of AS. Here we describe the phenotypic expression in 14 AS cases involving eight UBE3A mutations. These comprise 11 familial cases from five families and three sporadic cases. Subtle differences from the typical phenotype of AS were found. Consistent manifestations were psychomotor delay, a happy disposition, a hyperexcitable personality, EEG abnormalities, and mental retardation with severe speech impairment. The other main manifestations of AS, ataxia, epilepsy, and microcephaly, were either milder or absent in various combinations among the patients. In addition, myoclonus of cortical origin was frequently observed with severe fits inducing myoclonic seizures. The majority of the patients were overweight. This study showed that ataxia, myoclonus, EEG abnormalities, speech impairment, characteristic behavioural phenotype, and abnormal head circumference are attributable to a deficiency in the maternally inherited UBE3A allele. Furthermore, analysis of mutation transmission showed an unexpectedly high rate of somatic mosaicism in normal carriers. These data have important consequences for genetic counselling.

Adolescent↗
PubMed1999

Chronic antioxidant use and changes in endothelial dysfunction: a review of clinical investigations.

There are tremendous clinical interest and speculation about the impact of reversing endothelial dysfunction. This paper reviews information from patient studies that have assessed the effect of chronic antioxidant use on endothelial dysfunction. A search of MEDLINE and Current Contents online, complemented by detailed analysis of references in the papers identified, was used to identify all studies pertaining to patients treated with oral antioxidants to modify endothelial dysfunction. Studies of single acute doses were excluded. Endothelium-mediated end points were vascular responses in conduit or resistance vessels, endothelial cell-monocyte interaction and measures of soluble adhesion molecules. Positive effects on conduit vessel dilation, endothelial cell-monocyte interactions and soluble adhesion molecules were common. Except for one study, negative effects were noted in resistance vessels. Further trials are required to clarify and define the impact of these findings on clinical outcome.

Administration, Oral↗
PubMed1999

[Possibility of false negative results in the diagnosis of lung neoplasms with computerized tomography].

PURPOSE: To describe the radiological appearance of overlooked malignant pulmonary lesions at CT and to analyze the reasons of misdiagnosis. MATERIAL AND METHODS: Ten patients with pulmonary malignant lesions (PML) overlooked at first CT examination were selected among patients with lung cancer who were referred to our institution between 1994 and 1997. CT scans were evaluated by consensus of two chest radiologists with different experience in chest radiology, who were blinded to the final diagnosis. RESULTS: The overlooked pulmonary lesions were 5 endobronchial cancers and 5 central solitary nodules. The mean diameter of the lesions ranged 1 to 2 cm. Furthermore, 7 patients had associated pleural and/or parenchymal abnormalities. The technical quality of CT examinations was considered good in 2 cases, acceptable in 6 cases, poor in 2 cases. PML were correctly identified in 6/10 cases by the first (more experienced) radiologist and in 4/10 by the second radiologist. Four cases were considered suspect for the presence of PML by the first radiologist, 2 by the second. CONCLUSIONS: Endobronchial location of the tumors and their small size were the most frequent causes of misdiagnosis of PML at chest CT in our series. However, a systematic evaluation of CT scans can reduce the percentage of missed lesions.

Aged↗
PubMed1999

[Clinical approach to mental retardation of genetic origin].

Etiological investigations of mental deficiencies and their syndromic analysis have greatly progressed with advancing knowledge in the field of genetics and the advent of new technical procedures. Fast diagnostic tests are now available for certain syndromes, particularly those related to micordeletions. Clinical diagnosis remains however the necessary prerequisite for ordering such tests. The clinical examination not only provides a detailed description of the physical condition, but also provides essential information on behavioral and cognitive disorders. Distinctive behavioral patterns observed in some syndromes are suggestive of a "behavioral phenotype". This pattern can be a valuable clue to diagnosis and also allows for early intervention and counselling specifically aimed at dealing with predicted behavioral abnormalities.

Behavior↗
PubMed1998

Characteristics of leukotriene biosynthesis by human granulocytes in presence of plasma.

The formation of leukotriene B4 (LTB4) by neutrophils stimulated with the ionophore A23187 or physiological stimuli in heparinized plasma was investigated. In comparison with neutrophils stimulated (A23187) in a protein-free buffered salt solution, neutrophils stimulated in plasma produced only trace amounts of LTB4. The addition of human recombinant LTA4-hydrolase or erythrocytes to plasma prior to A23187 stimulation strongly and selectively stimulated (> 4-fold) the formation of LTB4 supporting that neutrophils activated in plasma with A23187 release in the extracellular milieu most of LTA4 formed by the cells, and indicating that plasma proteins drastically slow down the further metabolism of LTA4 released by neutrophils. The formation of LTB4 was then investigated in GM-CSF-primed neutrophils stimulated with fMLP in plasma; levels of synthesis were very low and the addition of erythrocytes prior to stimulation strongly enhanced LTB4 synthesis, demonstrating that agonist-stimulated neutrophils also release most of LTA4 generated in the extracellular milieu. Investigations on the fate of LTA4 in plasma revealed that LTA4 was slowly degraded through an unknown process, i.e. not through the previously described non-enzymic hydrolysis resulting in the formation of dihydroxy derivatives of LTA4. Using neutrophils labeled with tritiated arachidonate, we also demonstrated that neutrophils stimulated in plasma with fMLP or A23187, almost exclusively use endogenous arachidonate, as opposed to plasma arachidonate, to generate 5-lipoxygenase products. Finally, experiments performed with purified eosinophils indicated that contrary to neutrophils, the eosinophils do not release LTA4, but directly release LTC4.

Asthma↗
PubMed1997

Suppression of leukotriene B4 biosynthesis by endogenous adenosine in ligand-activated human neutrophils.

Adenosine (Ado) has been shown to suppress several functional responses of human polymorphonuclear leukocytes (PMNs). The current study investigated whether endogenous Ado regulates the biosynthesis of leukotriene (LT)B4 in ligand-stimulated PMNs. Measurements of Ado in PMN resuspended in Hanks' buffered salt solution (HBSS) or plasma showed a cell concentration- and time-dependent accumulation of the nucleoside. The removal of endogenous Ado with either Ado deaminase or the blockade of its action by the Ado A2a receptor antagonist, 8-(3-chlorostyryl) caffeine, markedly increased LTB4 biosynthesis upon ligand stimulation in HBSS. Similarly, LTB4 synthesis by ligand-stimulated PMNs in plasma (containing recombinant LTA4 hydrolase to allow the conversion of protein-bound LTA4) was strongly enhanced by addition of Ado deaminase. Addition of red blood cells to suspensions of PMNs in plasma mimicked the effect of adding Ado deaminase and LTA4 hydrolase in enhancing LTB4 biosynthesis upon ligand stimulation. This effect of red blood cells on LTB4 biosynthesis was blocked by dipyridamole, an inhibitor of Ado transport, or captopril, an inhibitor of LTA4 hydrolase. These results demonstrate that endogenous Ado efficiently downregulates ligand-stimulated LTB4 biosynthesis in PMN suspensions, pointing out a potentially important regulatory function of Ado in inflammatory exudates. These results also unveil a dual role for red blood cells in upregulating LTB4 biosynthesis, namely, the removal of endogenous Ado and the conversion of LTA4 released by activated PMNs.

Adenosine↗
PubMed1997

Stüve-Wiedemann syndrome and defects of the mitochondrial respiratory chain.

The Stüve-Wiedemann syndrome (SWS) comprises short stature, congenital bowing of the long bones, respiratory distress, and recurrent episodes of unexplained hyperthermia. The skeletal radiographic changes include short and broad long bones, large metaphyses, internal cortical thickening, and angulation primarily of tibiae and femora, but also of humeri and forearm bones. We report 3 cases of SWS from 2 different unrelated consanguineous gypsy families. All 3 cases fulfilled the clinical and radiological criteria of SWS. Two patients died shortly after birth, whereas the third one was alive at the age of one year. Besides hyperthermic episodes, one patient had hyperaminoaciduria, hepatic failure, and megaloblastic anemia which prompted us to investigate mitochondrial respiratory chain in 2 cases. Abnormal results consisting of decreased activities of complex I and IV were found in both. The simultaneous occurrence of both SWS phenotype and abnormal mitochondrial metabolism in two unrelated cases strongly supports the hypothesis of a pathogenetic relationship between the two events. These cases may also be related to recent reports on the effects of the mitochondrial respiratory chain defects on embryogenesis.

Abnormalities, Multiple↗