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F Gambarelli

Publications and source records attributed to F Gambarelli.

At least 19 recordsLinked to original sources
PubMed2000

Crossing of antinuclear antibodies and anti-leishmania antibodies.

Visceral leishmaniasis or Kala-azar is an endemic parasitic infection in Mediterranean countries. We report an interesting case occurring in a 38-year-old woman suffering from systemic lupus erythematosus and secondary antiphospholipid syndrome. In our patient visceral leishmaniasis occurred during high dose-steroids treatment mimicking a flare of lupus. As the lupus resolved under immunosuppressive treatment, a reactivation of visceral leishmaniasis was observed and was confirmed by the successive serological tests which showed crossing of leishmania and antinuclear antibody titers. Our case shows that, faced with fever occurring in lupus patients in an endemic area, visceral leishmaniasis should be searched for before intensifying immunosuppressive treatments.

Adult↗
PubMed1997

Rapid identification of causative species in patients with Old World leishmaniasis.

Conventional methods for the identification of species of Leishmania parasite causing infections have limitations. By using a DNA-based alternative, the present study tries to develop a new tool for this purpose. Thirty-three patients living in Marseilles (in the south of France) were suffering from visceral or cutaneous leishmaniasis. DNA of the parasite in clinical samples (bone marrow, peripheral blood, or skin) from these patients were amplified by PCR and were directly sequenced. The sequences observed were compared to these of 30 strains of the genus causing Old World leishmaniasis collected in Europe, Africa, or Asia. In the analysis of the sequences of the strains, two different sequence patterns for Leishmania infantum, one sequence for Leishmania donovani, one sequence for Leishmania major, two sequences for Leishmania tropica, and one sequence for Leishmania aethiopica were obtained. Four sequences were observed among the strains from the patients: one was similar to the sequence for the L. major strains, two were identical to the sequences for the L. infantum strains, and the last sequence was not observed within the strains but had a high degree of homology with the sequences of the L. infantum and L. donovani strains. The L. infantum strains from all immunocompetent patients had the same sequence. The L. infantum strains from immunodeficient patients suffering from visceral leishmaniasis had three different sequences. This fact might signify that some variants of L. infantum acquire pathogenicity exclusively in immunocompromised patients. To dispense with the sequencing step, a restriction assay with HaeIII was used. Some restriction patterns might support genetic exchanges in members of the genus Leishmania.

Adolescent↗
PubMed1996

[Resistance of Leishmania infantum to Glucantime: risk factors and therapeutic management].

BACKGROUND: Resistance to antimonial drugs is rarely observed in immunocompetent patients. CASE REPORT: A 1-year-old girl was admitted suffering from persistent fever. A diagnosis of visceral leishmaniasis was made. The patient was given two courses of meglumine antimoniate (Glucantime) (60 mg/kg/d for 15 days) and one course of 12 injections of pentamidine (4 mg/kg). She relapsed 8 months later and failed to respond to Glucantime. Immunological tests performed during the relapse showed a suppression of the T cell response to Leishmania antigen and no production of interferon gamma. The patient was then successfully given liposomal amphotericin B (3 mg/kg/d for 10 days). She was asymptomatic 9 months later and had acquired specific cellular immunity against Leishmania. CONCLUSION: Deficient cell-mediated immunity and interferon gamma production are some factors responsible for decreased sensitivity to antimonial drugs. The WHO recommendations treating visceral leishmaniasis with prolonged administration of Glucantime may prevent relapses. Liposomal amphotericin B could be an alternative treatment.

Animals↗
PubMed1994

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

AIDS-Related Opportunistic Infections↗
PubMed1993

Isolation and characterization of a repetitive DNA sequence from Leishmania infantum: development of a visceral leishmaniasis polymerase chain reaction.

To construct a DNA probe specific for protozoa that cause visceral leishmaniasis, we cloned Pst I fragments of Leishmania infantum genomic DNA into a Bluescript II SK vector. A clone of 4.3 kb that contained a highly repetitive sequence was isolated and cut with three restriction enzymes: Hae III, Rsa I, and Sau 3A. After a new molecular cloning step, we isolated and sequenced a 140-basepair (bp) fragment. Two oligonucleotides were synthesized to be used as primers for a polymerase chain reaction. Using this probe, we detected an amount of DNA equivalent to one promastigote of L. infantum. This probe showed a high specificity; all protozoa tested that cause visceral leishmaniasis and L. major (one of the causative agents of Old World cutaneous leishmaniasis) showed a 100-bp amplified sequence, whereas other Leishmania strains showed a signal of a different size or else no signal. Moreover, no amplified sequence was obtained with other pathogenic parasites tested (Trypanosoma brucei, T. cruzi, Plasmodium falciparum, Pneumocystis carinii, and Toxoplasma gondii).

Animals↗
PubMed1989

Electrophysiological and morphological properties of type C vagal neurons in the nodose ganglion of the cat.

Some passive and active electrical properties of type C neurons were studied intracellularly, in situ, in the nodose ganglia of adult cats. From the neuronal responses to hyperpolarizing and depolarizing rectangular current pulses it was possible to determine the input resistance (34.4 M omega) and specific membrane resistance (2373 omega.cm2). Significant changes in magnitude and duration of the action potential evoked by vagal stimulation result from changes in the resting potential caused by the passage of steady polarizing currents across the cell membrane. The action potentials evoked by infranodose vagal stimulation had a long duration, a long latency and comprised several components. The fast main spike was followed by a long post-hyperpolarization. The double shock technique showed that the fast main potential was composed of an initial segment spike ('A spike') and a somatic spike ('S spike'), and made it possible to determine the somatic refractory periods. After electrical identification of the cells, horseradish peroxidase was injected ionophoretically into the soma, and it was shown that the central processes were about four times smaller in diameter than the peripheral processes.

Action Potentials↗
PubMed1988

[A simple method for cloning Leishmania spp].

A rapid and simple technique for isolation of clones of Leishmania spp. was developed. This method consists to adapt promastigote forms of Leishmania infantum to an easily realized medium: the Panmede solid medium. We obtained cloned-population of this parasite for epidemiologic and toxonomic studies.

Animals↗
PubMed1987

Modulation of the vestibulo-ocular reflex by serotonin in the rat.

The effects of intraventricular injection of serotonin (5-HT) and its agonists and antagonists on the amplitude of the vestibulo-ocular reflex were studied in chronic implanted rats. 5-HT (10(-5) M) triggers an increase of the amplitude of the reflex which lasts 30 min. Similar results are obtained when N,N-dimethyl-5-methoxytryptamine (10(-3) M) is introduced into the ventricular cannula. The increasing effects observed both with 5-HT and N,N-dimethyl-5-methoxy-tryptamine are abolished by methiothepin, a potent antagonist of 5-HT receptors. Injection of indirect agonists like pargyline, a monoamine oxidase inhibitor, or fluoxetine, a potent inhibitor of 5-HT reuptake, is followed by an increase of the amplitude of the vestibulo-ocular reflex. These results indicate that 5-HT can modulate the activity of the vestibulo-ocular pathway and muscular tone of extraocular muscles. Location and involvement of various modulating 5-HT sites are discussed.

Animals↗
PubMed1985

Early postnatal development of EEG and sleep-waking cycle in two inbred mouse strains.

The postnatal maturation of brain electrical activity and sleep-waking cycle were studied in two inbred mouse strains (C57BL and BALBc), previously differentiated in their sleep patterns at adult age. Genetic differences are evident during the first postnatal period (until day 12) in the maturation of electrical activity which is both earlier and slower in C57BL than in BALBc. On the other hand, from day 12 onwards, as soon as the sleep-waking cycle can be defined by using EEG morphology to select quiet sleep (QS) and active sleep (AS) C57BL is characterized by a higher amount of AS and a lower amount of waking (W) than BALBc, as found in juvenile and adult mice. These differences appear a little later when the recordings are performed on animals which are isolated instead of being left with the rest of the litter.

Age Factors↗
PubMed1983

Sleep variations in C57BL and BALBc mice from 3 weeks to 14 weeks of age.

The evolution of sleep patterns during the diurnal period was studied in C57BL and BALBc mice from 3 to 14 weeks of age. Quantitative analysis of the hypnograms reveals that the main sleep changes occur between weeks 3 and 4 in the two strains. This period is characterized by a decrease of the percentage of paradoxical sleep in BALBc strain, due to a simultaneous drop in the mean number and duration of the episodes. During this time C57BL strain exhibits an increase in the percentage of slow wave sleep, resulting from a rise in the mean number of episodes. At the same time the percentage of awake state decreases in C57BL mice. In the adults these changes result in differences between the strains in sleep pattern that are characterized by a higher percentage of paradoxical and slow wave sleep in C57BL than in BALBc mice. As regards the results obtained, the maturation of sleep mechanisms and particularly of the paradoxical sleep seems to be different in C57BL and in BALBc mice.

Aging↗
PubMed1981

Comparison of brain serotoninergic systems in C57BL and BALBc mice during development.

Adult C57BL and BALBc mice will exhibit differences in behaviour and in their sleep patterns which may be correlated with monoamine content. In this study, we measured the endogenous levels of serotonin (5-HT), tryptophan (TRP), 5-hydroxyindole acetic acid (5-HIAA), noradrenaline (NA) and dopamine (DA) in the forebrain and hindbrain regions of these strains of mice from day 1 to 12 weeks of age. Using the micropunch technique and a radioenzymatic method, we also determined the endogenous 5-HT levels in the nuclei raphe dorsalis, centralis, magnus-pallidus and obscurus. During development, NA levels in the brain stem are higher in the C57BL than in the BALBc mice. From 5 weeks of age onwards, the levels of 5-HT, DA and NA in the forebrain are also higher in the C57BL mice. However, no differences in 5-Ht and DA content was found for the brain stems of these two strains. When the 5-HT levels in the different raphe nuclei were analyzed, the nucleus raphe dorsalis of the BALBc showed a higher 5-HT content.

Aging↗