Search PubMed⌕ Search

Biomedical subjects

H Duclos

Publications and source records attributed to H Duclos.

At least 19 recordsLinked to original sources

[Familial orthochromatic leukodystrophy: clinicopathological study of two cases].

This paper reports the clinico-pathological data in a French family with orthochromatic leukodystrophy. The parents were first cousins and had seven children. Among those, two sisters and one brother presented with neurological signs, with onset around the 5(th) decade, including a dementing syndrome of frontal type, a tetrapyramidal syndrome, seizures, and, in one sibling, a cerebellar syndrome. CT scan or MRI showed diffuse involvement of the white matter. The neurological signs worsened progressively leading to death within 11 and 22 months. Neuropathological examination was performed in two cases. It revealed characteristic orthochromatic leukodystrophy. In one case, the presence of pigmented macrophages and astrocytes was suggestive of Van Bogaert and Nyssen disease. However there were some atypical features including the absence of pigmented cells in the second case whose clinical course was shorter, and the cavitary appearance of the white matter changes with a relative increase in the number of oligodendrocytes raising the issue of a possible link between this condition and cavitary orthochromatic leukodystrophies.

Aged↗

Pharmacological profile of LF 16-0687, a new potent non-peptide bradykinin B2 receptor antagonist.

LF 16-0687 (1-[[2,4-dichloro-3-[[(2,4-dimethylquinolin-8-yl)oxy] methyl]phenyl]sulfonyl]-N-[3-[[4-(aminoimethyl) phenyl] carbonylamino]propyl]-2(S)-pyrrolidinecarboxamide) has been selected from a large-scale medicinal chemistry program for further development. In competition binding studies using [3H]bradykinin (BK), LF 16-0687 bound to the human, rat and guinea-pig recombinant B2 receptor expressed in CHO cells giving K(i) values of 0.67 nM, 1.74 nM and 1.37 nM, respectively. It also bound to the native BK B2 receptor from human umbilical vein (HUV), rat uterus (RU) and guinea-pig ileum (GPI) giving K(i) values of 0.89 nM, 0.28 nM and 0.98 nM, respectively. It inhibited BK-induced IP1, IP2 and IP3 formation in INT407 cells yielding pK(B) values of 8.5, 8.6 and 8.7, respectively. In isolated organs experiments, LF 16-0687 behaved as a competitive antagonist of BK-mediated contractions giving pA2 values of 9.1 in HUV, 7.7 in RU and 9.1 in GPI. Binding and functional studies performed over 40 different receptors revealed that LF 16-0687 was selective for the BK B2 receptor. A continuous intravenous infusion of LF 16-0687 antagonized in a dose-dependent manner and with a rapid onset of action BK-induced hypotensive response. Subcutaneous administration of LF 16-0687 at 1.1 micromol/kg to rats markedly reduced BK-induced edema of the stomach (- 69%), duodenum (-65%) and pancreas (-56%).

Animals↗

Pharmacological and molecular evidence for kinin B1 receptor expression in urinary bladder of cyclophosphamide-treated rats.

1. In the present study, we developed an experimental model of cystitis induced by cyclophosphamide (CYP). In order to characterize des-Arg9-BK-induced contraction on the urinary bladder (UB) during the development of inflammation and to quantify kinin B1 receptor gene expression using a quantitative RT - PCR technique. 2. In the presence of peptidase inhibitors captopril (10 microM), DL-thiorphan (1 microM) and DL-2-mercaptomethyl-3-guanidino-ethylthiopropanoic acid (MERGEPTA 5 microM), bradykinin (BK) (0.3 - 3,000 nM) evoked a concentration-dependent contraction of rat UB which was not different between the CYP- and vehicle-treated groups. Unlike BK, des-Arg9-BK (0.3 - 100,000 nM) did not contract UB from vehicle-treated rats but contracted vigorously bladder strips from CYP-treated rats 14, 24 and 168 h after treatment. In UB of 24 h treated rat, the pD2 value of des-Arg9-BK was 7.3+/-0.1. 3. The cyclo-oxygenase inhibitor indomethacin (3 microM) reduced by 30% the maximal response of des-Arg9-BK. Both the kinin B1 receptor antagonists des-Arg9-[Leu8]BK (10 microM) and des-Arg10-Hoe 140 (10 microM) produced a rightward shift of the concentration-response curve to des-Arg9-BK yielding pKB values of 6.8+/-0.2 and 7.2+/-0.1, respectively, whilst the kinin B2 receptor antagonist Hoe 140 (1 microM) had no effect. 4. After CYP treatment, mRNA coding for the kinin B1 receptor appeared predominantly in UB. In this organ, the induction was progressive, reaching a maximum 48 h after CYP treatment. 5. In conclusion, the present study provides strong evidence for an induction of kinin B1 receptors in UB of CYP-treated rats. This was associated at a molecular level with an increase in mRNA expression of the gene coding for the kinin B1 receptor. This kinin receptor displayed the whole features of a classical rat kinin B1 receptor.

Acrolein↗

In vitro and in vivo effects of the new nonpeptide bradykinin B2 receptor antagonist, LF 16-0335C, on guinea-pig and rat kinin receptors.

Activation of the kinin-kallikrein system and stimulation of bradykinin (BK) B2 receptors are thought to play an important role in the pathophysiology of inflammation and pain. In the present study, we report the pharmacological properties of a novel nonpeptide bradykinin B2 receptor antagonist, LF 16-0335C, (1-[[3-[(2,4-dimethylquinolin-8-yl) oxymethyl]-2,4-dichloro-phenyl]sulfonyl]-2(S)-[[4-[4- (aminoiminomethyl)-phenylcarbonyl]piperazin-1-yl]carbo nyl]pyrrolidine, 2HCl). In binding studies, LF 16-0335C competed with [3H]bradykinin giving Ki values of 1.65 +/- 0.36 nM and 2.20 +/- 0.30 nM in membrane preparations from rat uterus (RU) and guinea-pig ileum (GPI), respectively. In functional experiments, LF 16-0335C inhibited in a competitive manner BK-induced contractions of both isolated RU and GPI, leading to calculated pA2 values of 7.70 +/- 0.70 and 8.30 +/- 0.30, respectively. The inhibitory effect of LF 16-0335C was fully reversible by washing in the guinea-pig ileum. In vivo, LF 16-0335C given intravenously inhibited in a dose-dependent manner BK-induced hypotension in both animal species, although it was more potent in the guinea-pig than in the rat (ED50, 2.5 +/- 1.6 micrograms/kg versus 22.6 +/- 2.3 micrograms/kg). BK is a potent constrictor of guinea-pig airways and this effect was markedly attenuated by LF 16-0335C. In contrast, LF 16-0335C did not affect histamine- and acetylcholine-induced hypotensive response in the rat. We conclude that LF 16-0335C is a potent and selective nonpeptide B2 receptor antagonist which equally binds to the rat and guinea-pig receptor but displays a different in vivo potency in the two species. Therefore, this drug represents a useful tool to better assess the role of bradykinin in pathophysiological conditions.

Acetylcholine↗

LF 16.0335, a novel potent and selective nonpeptide antagonist of the human bradykinin B2 receptor.

1. In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1-[[3-[(2,4-dimethylquinolin-8-yl)oxymethyl]-2,4-dichloro-p henyl]sulphonyl] -2(S) - [[4 -[4-(aminoiminomethyl)phenylcarbonyl]piperazin-1-yl]ca rbonyl]pyrrolidine), a novel and potent nonpeptide antagonist of the human bradykinin (BK) B2 receptor. 2. LF 16.0335 displaced [3H]-BK binding to membrane preparations from CHO cells expressing the cloned human B2 receptor, INT 407 cells and human umbilical vein with Ki values of 0.84+/-0.39 nM, 1.26+/-0.68 nM and 2.34+/-0.36 nM, respectively. 3. In saturation binding studies performed in INT 407 cell membranes in the presence or absence of LF 16.0335, max values of [3H]-BK were not significantly changed suggesting that LF 16.0335 behaves as a competitive antagonist. 4. LF 16.0335 had no affinity for the cloned human kinin B1 receptor stably expressed in 293 cells. In addition, this compound at 1 microM did not significantly bind to a range of 40 different membrane receptors and eight ion channels except muscarinic M2 and M1 receptors for which an IC50 value of 0.9 and 1 microM was obtained. 5. BK stimulates in a concentration-dependent manner phosphoinositosides (IPs) production in cultured INT 407 cells. Concentration-response-curves to BK were shifted to the right in the presence of LF 16.0335 (0.1 microM) without reduction of the maximum. LF 16.0335 inhibited the concentration-contraction curve to BK in the human umbilical vein giving a pA2 value of 8.30+/-0.30 with a Schild plot slope that was not different from unity. 6. These results demonstrate that LF 16.0335 is a potent, selective and competitive antagonist of the human bradykinin B2 receptor.

Amidines↗

[Cerebral hemosiderosis related to hereditary ceruloplasmin deficiency. Clinical familial case study].

A 59-year-old patient progressively developed dementia, hallucinations and facial dyskinesia. Brain T and T2-weighted MRI images showed low signal intensity on basal ganglia specially striatum, posterior thalamic and dentate nuclei. He had no evidence of ceruloplasmin and a high level of ferritin in the serum. Liver biopsy confirmed accumulation of iron in the cytoplasm of many hepatocytes. Similar clinical and biological signs were also observed in two brothers. All the three siblings were homozygous for a hereditary ceruloplasmin deficiency. This new clinico-pathological entity, first described in 1987, is different from Wilson's disease, Hallervorden-Spatz's disease and idiopathic hemochromatosis and linked to a mutation of the ceruloplasmin gene located on chromosome 3.

Brain↗

[Interhemispheric disconnection syndrome caused by partial infarction of the corpus callosum: neuropsychological study and MRI].

A partial syndrome of hemisphere disconnection was observed in a 63 year-old woman, following an anterior and middle corpus callosum infarct on MRI. Notably, we found left ideomotor apraxia, diagonistic apraxia, left-year extinction on dichotic listening, but no left-hand anomia nor left visual field anomia. A left tactile extinction in dichaptic condition is interpreted as resultant of a dysregulation of the attentional balance between the two hemispheres. This detailed neuropsychological study permits a correlation between the callosal syndrome and the lesion. We suggest that an occlusion of the anterior callosal artery could explain this limited ischemia.

Cerebral Infarction↗

Complete nucleotide sequence and viral envelope protein expression of a hepatitis B virus DNA derived from a hepatitis B surface antigen-seronegative patient.

An HBV strain isolated from a patient lacking conventional serological markers of HBV infection was characterized. The complete nucleotide sequence was determined following PCR amplification. Only 22 nucleotide substitutions were found relative to the reported sequence of the ayw subtype. Five of these point mutations in the preS/S and preC/C genes led to amino acid substitutions and, with one exception, were located in regions coding for antigenic determinants of viral envelope or capsid proteins. Eight amino acid substitutions were located in terminal protein and the spacer domain of the polymerase gene product. Despite these amino acid changes, transient expression of the preS2 and S envelope proteins in eucaryotic cells yielded viral proteins detectable in the culture medium with polyclonal and monoclonal anti-preS2 and -S antibodies. These data conclusively demonstrate persistent infection by HBV in subjects without HBV serological markers. The absence of conventional HBV serological markers is probably due to several factors: a low level of viral replication, some genetic modifications, as well as an abnormal immune response to the virus.

Animals↗

[Spinal infarction in the anterior spinal territory with possible relation with bilharziasis].

We report a case of spinal cord infarction in the anterior spinal artery territory with selective involvement of the anterior horns. A 35-year-old Mauritanian woman was hospitalized because of an acute and severe flaccid paraplegia without any sphincter dysfunction or sensory disturbance. MRI abnormalities (hypersignal on T2-weighted sequences) were restricted to the anterior horns of the lower thoracic spinal cord and conus medullaris. Adamkiewicz's artery appeared abnormally thin at arteriography. The infarction was probably related to vasculitis of schistosomal origin.

Adult↗

Cytomegalovirus infection and trans-activation of HIV-1 and HIV-2 LTRs in human astrocytoma cells.

Susceptibility of a human astrocytoma cell line to human cytomegalovirus (HCMV) infection was investigated. Infection of U-373MG astrocytoma cells with two strains of HCMV resulted in both production of extracellular, infectious virus and expression of immediate early and early antigens within 18 hours and late antigens after 72 hours of infection. The kinetics of infection in U-373MG cells were the same as in human diploid fibroblasts (MRC-5). Since HCMV and human immunodeficiency virus (HIV) have reportedly been found in astrocytic cells in vivo, we studied the possible interaction between HCMV and HIV long terminal repeat (LTR) elements in this cellular environment. HCMV infection transactivated the LTR of HIV-1 and HIV-2 to similar levels. Interestingly, transfection of these cells with infectious HIV-1 provirus did not result in expression of gag, env, or F proteins detectable by immunofluorescence. However, provirus gene expression was not completely silent, since it transactivated HIV-1 LTR. The level of this transactivation was similar to that seen following cotransfection with a tat expression vector. These results suggest that opportunistic infection with HCMV may reactivate latent HIV genomes in glial cells.

Animals↗

[Intramedullary neurenteric cyst without an associated malformation. Case report].

The authors report a case of an intramedullary neurenteric cyst without any associated dysraphic lesion. Unlike extramedullary intradural forms, this type of malformation remains rare. Our observation is one of the first to have been evaluated by magnetic resonance imaging. Theories concerning the embryogenesis of neurenteric cysts as well as their clinical characteristics and surgical treatment are discussed.

Adult↗

[Demonstration of a 100-110 kd immunosuppressive fraction in the seminal fluid of swine].

The boar seminal fluid was fractionated in order to purify semen immunosuppressive factors. This species was chosen for its extremely abundant semen which allows large scale purifications and analyses. The fractions were tested on Balb/c mice spleen cells stimulated with LPS or PHA. The most active fraction was found in the 100-110 kd molecular weight range. The immunosuppressive activity occurred on both B and T cells, but was higher on the former. The active molecule is likely to be a protein. Another fraction of greater than 500 kd MW was also immunosuppressive but its activity disappeared by concentration. It possibly contained aggregates of the 100 kd molecules. The biological role of these immunosuppressive agents could be to protect sperm against female local immune reactions. Similar molecules in human semen might exist and favor the occurrence of acquired immunodeficiency syndrome in male homosexuals.

Animals↗

Differential effects of azathioprine on T cells regulating murine B-cell function.

We describe selective effects of azathioprine (Az) on T-cell subpopulations regulating the primary in vitro antibody response of mouse spleen cells to the T-independent antigen TNP-polyacrylamide. This response is susceptible to the effect of two kinds of non-specific suppressor cells: (i) spontaneously-induced suppressor, generated after 4-5 days culture in the presence of 2 micrograms/ml of concanavalin A (Con A). Indeed, both these precultured cells lead to a cell dose-dependent suppression of the anti-TNP response when transferred at the initiation of antigen-stimulated fresh cell cultures. T cells are the effectors of both these suppressions and seem to directly suppress the B-cell response. We tested the in vitro effect of Az (10(-1) micrograms/ml) on the generation of these two sets of suppressors. Whereas that of Con-A-induced suppressors proves to be resistant, that of spontaneously-induced T suppressors is totally prevented by the addition of Az in the preculture medium. Instead, Az treatment allows the manifestation of a spontaneously-induced helper T cell, simultaneously generated, which is able to increase a T-independent antibody response and quite resistant to the in vitro effect of Az. Thus, this study demonstrates that different subpopulations of T lymphocytes regulating the B-cell antibody response exhibit a selectivity to Az, implying different cell proliferation requirements and/or different cellular origin.

Acrylic Resins↗

Macrophage requirement for the in vitro response to an insolubilized T-independent antigen.

The role of macrophages in the in vitro response of mouse spleen cells to the insolubilized, T-independent antigen trinitrophenylated polyacrylamide (TNP-PAA) is demonstrated by the following points. The response is abolished by filtration on Sephadex G-10 and can be restored by the addition of splenic adherent cells, deficient in either B or T cells, or by 2-mercaptoethanol (2ME). It is suppressed upon elimination of phagocytic cells by silica, and restored by 2-ME. 2-ME can restore a normal response from zero, in cultures depleted of both adherent and phagocytic cells, and is efficient in the absence of mature T cells. Experiments in microcultures show that large numbers of macrophages can stimulate a supra-optimal response from B cells. This response is only obtained in the presence of the antigen, and is specific for TNP. These results show that microphages, probably by their polyclonal B-cell activator (PBA) property, play a role in the specific response to TNP-PAA. This prompts us to discuss the respective roles in the B-cell response of this PBA activity and of the interaction of the antigen with the specific B-cell receptors.

Animals↗