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C Guyot

Publications and source records attributed to C Guyot.

At least 19 recordsLinked to original sources
PubMed2004

Sonographic findings in Beckwith-Wiedemann syndrome related to H19 hypermethylation.

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome associated with congenital malformations and tumour predisposition. BWS results from variable mutations or epigenetic modifications of imprinted genes in the 11p15 chromosomal region. We present a fetus with mild general overgrowth and bilateral enlarged echogenic kidneys with loss of the corticomedullary differentiation in which prenatal diagnosis of BWS was suspected. The rest of the fetal anatomy and the amniotic fluid volume appeared normal. After termination of the pregnancy, molecular analysis confirmed the diagnosis of BWS by showing an isolated hypermethylation of the H19 gene.

Adult↗
PubMed2004

In vitro selection and characterization of resistance to macrolides and related antibiotics in Mycoplasma pneumoniae.

Macrolide-resistant mutants of Mycoplasma pneumoniae were selected in vitro from the susceptible reference strain M129, by 23 to 50 serial passages in subinhibitory concentrations of macrolides and related antibiotics, erythromycin A, azithromycin, josamycin, clindamycin, quinupristin, quinupristin-dalfopristin, pristinamycin, and telithromycin. Mutants for which the MICs are increased could be selected with all antibiotics except the streptogramin B quinupristin. Portions of genes encoding 23S rRNA (domains II and V) and ribosomal proteins L4 and L22 of mutants were amplified by PCR, and their nucleotide sequences were compared to those of the susceptible strain M129. No mutation could be detected in domain II of 23S rRNA. Two point mutations in domain V of 23S rRNA, C2611A and A2062G, were selected in the presence of erythromycin A, azithromycin, josamycin, quinupristin-dalfopristin, and telithromycin. Mutants selected in the presence of clindamycin and telithromycin harbored a single amino acid change (H70R or H70L, respectively) in ribosomal protein L4, whereas insertions of one, two, or three adjacent glycines at position 60 (M. pneumoniae numbering) were selected in the presence of both streptogramin combinations. Telithromycin was the sole antibiotic that selected for substitutions (P112R and A114T) and deletions ((111)IPRA(114)) in ribosomal protein L22. Three sequential mutational events in 23S rRNA and in both ribosomal proteins were required to categorize the strain as resistant to the ketolide. Azithromycin and erythromycin A were the only selector antibiotics that remained active (MICs, 0.06 and 1 micro g/ml, respectively) on their mutants selected after 50 passages.

Anti-Bacterial Agents↗
PubMed1999

Chronic renal failure after Puumala virus infection.

Chronic renal failure has never been described after Puumala hantavirus infection, which usually causes acute renal failure with spontaneous full recovery. We report a 15-year-old boy who presented with Puumala hantavirus infection and initial severe acute renal failure. His renal function gradually improved, but more than 2 years after the acute episode it was still moderately impaired, with a creatinine clearance of about 60 ml/min per 1.73 m(2)

Adolescent↗
PubMed1998

Floral Origin Markers of Chestnut and Lime Tree Honeys.

The apiculture industry is more and more interested in finding typical markers to authenticate floral origin of honeys. With this aim, some reliable volatile compounds were proposed to identify origin of lime tree and chestnut samples. A dichloromethane extraction followed by a Likens-Nickerson simultaneous steam distillation/solvent extraction led to representative honey extracts. About 400 volatile compounds were separated by gas chromatography, but only a few authenticated the floral origin of honeys. Chestnut honeys are distinguishable from other origins by high concentrations of acetophenone, 1-phenylethanol (>88 ppb), and 2-aminoacetophenone (>154 ppb). Lime tree honeys are characterized by enhanced amounts of shikimate pathway derivatives (ethylmethylphenol isomer (>31 ppb), 4-tert-butylphenol, estragole (>51 ppb), and p-methylacetophenone but also by high concentrations of monoterpene-derived compounds (menthol, thymol, 8-p-menthene-1,2-diol, and carvacrol (>76 ppb)) and methyl(1-methylethenyl)benzene.

Journal Article↗
PubMed1996

Risk factors for chronic rejection in pediatric renal allograft recipients.

To determine the risk factors predictive of graft loss from chronic rejection in pediatric renal allograft recipients, we reviewed the collaborative study database of the Société de Néphrologie Pédiatrique which registered 314 grafts from January 1987 to December 1991. Of the 289 grafts analyzed, 71 failed during follow-up, chronic rejection being the most common cause of graft loss (35%). The clinical features of the chronic rejection group (n = 25) were compared with those of the group without failure (n = 218). The variables tested by monovariate analysis were cyclosporine dose at 1 year, donor type, donor and recipient age, and acute rejection episodes. The incidence of graft loss due to chronic rejection was 4% (4/109) in patients who had no acute rejection and 16% (21/134) in those with at least one acute rejection episode (P = 0.002). Donor age (< or = 5 years) was a risk factor for chronic rejection (P = 0.024). Recipient age and donor type were not significantly different between the chronic rejection group and the control group. Using time-dependent covariates, the risk factors were an acute rejection episode (P = 0.003) and low cyclosporine doses at 1 year (P = 0.02). We conclude that acute rejection and low cyclosporine doses in these pediatric patients were risk factors for graft loss due to chronic rejection.

Adolescent↗
PubMed1996

[Trial of prevention of severe Haemophilus influenzae type b infections and trial of tolerance, after PRP-T vaccination, in the Val-de-Marne region].

BACKGROUND: Protein-polysaccharide conjugate H influenzae vaccine is now routinely recommended for infants. To assess the vaccine's protective efficacy against invasive H influenzae infections and its safety, we conducted a study in the Val-de-Marne area of France. METHODS: From April 1991 to April 1993, 22,443 children less than 5 years of age were given PRP-T vaccine. Infants less than 6 months were given three doses whereas those between 6 and 12 months received only two doses, and children over 1 year of age received one dose. According to the infant's DTP-IPV vaccination status, PRP-T was administered alone or reconstituted extemporaneously with DTP-IPV. The immunogenicity of the conjugate vaccine was assessed after three doses in 100 infants under the age of 6 months. RESULTS: The PRP-T vaccine administered alone was safe. The reactions were more frequent when PRP-T vaccine was combined with DTP-IPV vaccine but they were comparable in frequency and severity to those observed after DTP-IPV vaccination. Before 1992, 18 Hib infections were reported each year in the Val-de-Marne region. During the study, only three Hib infections were reported each year. CONCLUSIONS: The fall in incidence of Hib infections, greater than expected, suggests a widespread immune effect of the vaccine, possibly due to a decrease in Hib nasopharyngeal carriage. The antibody titres to each component of vaccine were comparable to those observed in previous clinical infant studies.

Antibodies, Viral↗
PubMed1996

Interstrain variations in the cytomegalovirus (CMV) glycoprotein B gene sequence among CMV-infected children attending six day care centers.

Using the shell vial assay and sequence analysis of a variable region of the glycoprotein B (gB) gene, cytomegalovirus (CMV) excretion rates in urine and virus transmission were studied among 93 children from six day care centers (DCCs). During a 6-month period, excretion rates differed significantly between DCCs (P < .001). The 6 gB gene sequences, obtained from 24 CMV-infected children, were classified in four previously defined groups. In five DCCs, 2 or 3 strains cocirculated, and none was dominant. Infection could have been acquired outside the DCC for 2 children and inside it for 9. Two children from the same DCC had mixed infections. No differences in hygiene, child care practices, or experience and level of qualification of the staff could explain this wide variety of excretion rates between DCCs. The distribution of gB gene patterns observed does not suggest that 1 type was dominant or more efficiently transmitted.

Base Sequence↗
PubMed1995

Deletions of both alpha 5(IV) and alpha 6(IV) collagen genes in Alport syndrome and in Alport syndrome associated with smooth muscle tumours.

Diffuse oesophageal leiomyomatosis (DL), an inherited smooth muscle proliferation process, has been reported to be associated with Alport syndrome (AS), a familial nephropathy, mainly dominant X-linked inherited, and characterized by ultrastructural changes of the glomerular basement membrane. The COL4A5 gene, encoding the alpha 5 chain of type IV collagen, has been identified as the site of mutations in families with X-linked AS. Recently, a novel alpha 6(IV) collagen chain encoding gene has been mapped closely upstream of COL4A5, and disruption of the 5' end of both genes has been reported in four patients with DL and AS (DL-AS). Here, we report a long-range restriction map around the COL4A6 locus, and show that the COL4A5/COL4A6 deletion observed in seven patients with DL-AS encompasses only the two first exons of COL4A6, with a breakpoint located in the second intron of COL4A6, whose size exceeds 65 kb. Furthermore, we demonstrate that three patients with AS without DL, known to have a deletion of the 5' part of the COL4A5 gene, display a larger deletion in COL4A6. Moreover, a COL4A6 mRNA product was detected by reverse-transcription-polymerase chain reaction in an oesophageal tumour sample of a patient with DL-AS. These results suggest that DL-AS could be caused by an abnormal truncated alpha 6(IV) chain.

Adolescent↗
PubMed1993

Epidemiology of Haemophilus influenzae type b disease in France.

Results are reported of an epidemiological study which spanned ten years and was carried out in two French departments. A total of 277 cases of Hib disease occurring in children < 5 years old are reported and, in this age group, the incidence is evaluated at 21/100,000. Meningitis accounted for 64% of infections and epiglottitis for 7%. While the overall mortality rate was 3.3%, death was secondary to meningitis in 7/8 cases. Sequelae, which were all related to meningitis, were major in 1.2% of cases, severe in 9% of cases, and involved some hearing loss in 3.3% of cases. The monitoring networks set up in the two departments were characterized by sensitivities of 87 and 94%, respectively. They should prove useful in assessing the impact of vaccination, when large-scale implementation of vaccination has spread to both departments.

Child, Preschool↗
PubMed1993

[Antenatal form of Bartter's syndrome].

Six cases of tubular disorder of antenatal onset responsible for biological manifestations characteristic of Bartter syndrome and severe hypercalciuria are reported. In all six cases, severe hydramnios occurred during pregnancy between the 26th and 28th week after the last menstrual period. All six patients were born prematurely; gestational age ranged from 20 to 35 weeks. Major polyuria with dehydration occurred immediately after birth. The amounts of water and sodium needed to compensate urinary losses ranged from 280 to 370 ml/kg/day and 25 to 43 mmol/kg/d, respectively, during the first two postnatal months. Decreased serum potassium levels and increased plasma levels of renin and aldosterone were seen in all six patients. Increased urinary excretion of calcium was evidenced during the first postnatal week in three cases. Urinary calcium excretion in the six patients ranged from 15 to 30 mg/kg/d. Nephrocalcinosis developed in all six patients and two patients developed urinary lithiasis. One patient died at one month of age from necrotizing enteropathy. The five remaining patients gradually developed severe growth failure with measurements between 4 and 5.5 SDs below the mean. These five patients had evidence of hyperparathyroidism including increased serum levels of parathyroid hormone (5/5), increased serum alkaline phosphatase activity (4/5), and roentgenographic bone changes (1/5). Ionized calcium assays performed in three of the five patients disclosed low values (range 1.25-1.47 mmol/l; mean = 1.35; normal values = 1.42-1.62), although total serum calcium levels were normal or high (range 2.16-2.98 mmol/l; mean 2.61; normal values = 2.45-2.65) probably as a result of chronic dehydration.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1990

[Dysthyroidism and Parkinson's disease].

Associations between hyperthyroidism and Parkinson disease have been reported. The treatment of the hyperthyroid state seems to improve the extrapyramidal symptomatology. We report a case of a woman suffering from Parkinson disease and hypothyroidism. The treatment with thyroxine increased parkinsonian tremor. Dopamine regulation of TSH circadian and pulsatile release is not clear. These observations stress the possible role of thyroid hormones in regulating dopaminergic metabolism.

Aged↗
PubMed1990

[Diffuse esophageal leiomyomatosis. Apropos of 3 cases].

Three cases of diffuse esophageal leiomyomatosis are discussed. Two of these are familial one, the mother being affected. These familial cases can occur in association with Alport's syndrome. The occurrence of a case of esophageal leiomyomatosis imply a familial survey and the search of a renal or ocular disease. The surgical treatment of this affection in sub total oesophagectomy with esophageal substitution (with the colon especially). The long term prognosis is unknown, with the risk of renal failure if Alport's syndrome is associated or of other leiomyomatous localisation.

Child↗