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Biomedical subjects

B Guillois

Publications and source records attributed to B Guillois.

At least 19 recordsLinked to original sources
PubMed1998

Relationship between bone mineralization and aluminium in the healthy infant.

OBJECTIVE: This prospective study was designed to assess the relationship between variations of serum Aluminium levels and bone mineralization, which is one of its target tissues, in healthy premature (PT) and fullterm (FT) infants. STUDY DESIGN: Lumbar spine bone mineral density (BMD) and content (BMC) studied by dual energy X-ray absorptiometry were compared to serum aluminium (S-Al), Ca (S-Ca), P (S-P), osteocalcin, alkaline phosphatase activity (S-AP), and 25 OH Vitamin D (25 OH D) by simple and multiple regressions in healthy PT (n = 44) following their hospital discharge and FT (n = 82). PT (gestational age at birth (mean +/- 1 s.d.) 32 +/- 2 weeks) and FT were 43 +/- 39 and 36 +/- 32 weeks old respectively. RESULTS: In PT multiple stepwise regression analysis including gestational age at birth, postconceptional age and postnatal age displayed only a significant correlation between BMD or BMC and postnatal age and a negative one with S-Al. In FT correlations were found between BMD or BMC and age and S-Ca. CONCLUSIONS: In PT, variations in blood Al are associated with developmental delays. Care should be taken to lessen Al levels, even in healthy PT babies.

Aging↗
PubMed1997

Detection of respiratory syncytial virus, parainfluenzavirus 3, adenovirus and rhinovirus sequences in respiratory tract of infants by polymerase chain reaction and hybridization.

BACKGROUND: Immunofluorescence assay (IFA) of viral antigens in nasal aspirates is largely used for the diagnosis of respiratory syncytial virus (RSV), parainfluenzavirus (PIV) type 3 and adenovirus (AdV) infections, whilst rhinovirus (RV) are detected by virus isolation technique (VIT) only. Using the two techniques, IFA and VIT, a significant number of specimens remain negative in spite of clinical and epidemiological presumptions of viral infection. OBJECTIVES AND STUDY DESIGN: The polymerase chain reaction (PCR) should improve the sensitivity of viral detection in clinical specimens. From October 1995 to March 1996, 277 nasal aspirates from hospitalized infants were tested simultaneously by IFA, VIT, polymerase chain reaction and hybridization with a DNA enzyme immunoassay (PCR-EIA) for RSV, PIV-3, AdV and RV. RESULTS: RSV were detected in 177 (64%) samples, PIV-3 in 23 (8%), RV in 40 (14%), and AdV in 30 (10%). PCR-EIA detected RSV in more samples 173 (62%) than IFA/VIT: 109 (39%) (P < 10(-7)). In most cases (79%), RSV-infected infants had lower respiratory tract disease, and routine and PCR techniques were positive. Out of the 23 PIV-3 infections, 12 were IFA/VIT- and PCR-EIA-positive, and 11 IFA/VIT-negative and PCR-EIA-positive. For RV, 35 (87%) specimens were PCR EIA-positive and 11 (27%) culture-positive; for AdV 30 samples were PCR-EIA-positive and four were culture-positive. Simultaneous viral infections were revealed in a significantly higher proportion than in conventional techniques: 18% (50/277) versus 2.5% (7/277); P < 10(-7). One RSV infection in four was associated with the presence of another virus, mainly PIV-3 (16 cases) and AdV (13 cases). CONCLUSIONS: PCR-EIA detects more positive-specimens than IFA/VIT, 1.5 times more for RSV, 1.9 for PIV-3, 4 for RV and 10 for AdV, respectively. This increased sensitivity of viral detection by PCR-EIA compared to the IFA/VIT could suggest that samples containing low levels of virus are missed by routine methods IFA/VIT, and consequently, RSV or PIV-3, and above all RV or AdV are overlooked as agents of respiratory diseases. However, apart from the fact that the economic and convenient aspects of virus diagnostic cannot be missed, it is difficult to answer the following questions: what is the meaning of the detection of a viral sequences in nasal aspirates of infants, or may PCR have detected virus in patients who would not developed disease?

Adenoviridae↗
PubMed1997

[Glucocorticoid-induced hypertrophic cardiomyopathy in premature infants: apropos of 4 cases].

BACKGROUND: The steroidal treatment used to prevent bronchopulmonary dysplasia (BD) in the preterm babies may be the cause of several complications, one of them being hypertrophic cardiomyopathy. CASE REPORT: Four infants developed hypertrophic cardiomyopathy during glucocorticoid (dexamethasone and/or betamethasone) treatment for bronchopulmonary dysplasia. In one of them, septal hypertrophy led to left ventricular outflow tract obstruction and congestive heart failure. All four were premature infants born after 2 weeks of gestation and weighing 780 to 1,080 g. The first echocardiographic changes appeared between the 4th and 15th day of the glucocorticoid course when the cumulated dose was respectively 1.82-1.87-3.51 and 3.86 mg/kg. Hypertrophic cardiomyopathy resolved completely between 2 and 4 weeks after cessation of the treatment. CONCLUSION: The glucocorticoid dosage to prevent BD should be reduced to 0.3 mg/kg/j and the myocardial function should be monitored by repeated echocardiograms during the first 15 days of treatment.

Betamethasone↗
PubMed1996

Induction of liver and kidney CYP1A1/1A2 by caffeine in rat.

Caffeine metabolism by hepatic microsomal P450 enzymes is well documented in experimental animals and humans. However, its induction effect on P450 enzymes has not been thoroughly studied. In a preliminary experiment, the time-dependent incubation of 1 mM caffeine with rat hepatocyte culture resulted in an increase of its own metabolic rate. The dose-dependent expression of rat hepatic and renal cytochromes (CYP) 1A1/1A2 was then investigated after per os administration of caffeine. P450 expression was monitored by using specific enzymatic activities and Northern blot analysis. Caffeine caused a dose-dependent elevation of hepatic CYP1A1/1A2 activities in microsomal preparations, which ranged from 1.7- to 6-fold for ethoxyresorufin O-deethylase and 3- to 8.9-fold for methoxy-resorufin O-demethylase according to the dose regimen of 50 and 150 mg caffeine/kg/day for 3 days, respectively. Northern blot analysis demonstrated that caffeine treatment increased liver CYP1A1 and CYP1A2 mRNA levels over the dose regimen of 50-150 mg caffeine/kg/day for 3 days, respectively. The result of this study demonstrates that caffeine increases its own metabolism in a dose-dependent manner and induces CYP1A1/1A2 expression through either transcriptional activation or mRNA stabilization.

Animals↗
PubMed1996

Evaluation of virological procedures to detect fetal human cytomegalovirus infection: avidity of IgG antibodies, virus detection in amniotic fluid and maternal serum.

Human cytomegalovirus (HCMV) is the most common cause of viral intrauterine infection and fetal damage largely due to maternal primary infection. Virological procedures which are able to detect HCMV fetal infection were evaluated. HCMV IgG antibodies were detected in 62.5% of the pregnant women and 1.47% had a primary infection. From March, 1992 to August, 1995, 29 seroconversions were observed, and in 64 other cases. HCMV IgM antibodies were detected in the first serological test. The mean IgG antibody avidity test (AI) was 31% for the 11 seroconversions tested and 74% in 32 cases where IgG and IgM HCMV antibodies were detected in the first serum. In the 29 HCMV seroconversions, 19 amniocentesis were carried out and 12 fetuses (41.4%) were infected in utero. In four amniotic fluids positive in culture and PCR, the fetus or newborns were infected and in one out of the two cordocentesis undertaken, hepatitis, anemia, and thrombocytopenia were noted. In four other cases, investigations seeking HCMV in amniotic fluid were negative whereas infants were infected at birth. Among the 64 cases with positive HCMV IgM and IgG antibodies detected in the first serological test, three fetuses were infected in utero, but no amniotic fluid was available in these cases. Amniotic fluids were studied in 39 cases, and HCMV detection by culture and PCR-hybridization was negative. HCMV DNA was detected in the maternal sera of five out of 21 pairs of seroconversions and in two cases on the first negative serum. The assay was also carried out on 50 of the 64 HCMV IgM positive sera. Two had detectable HCMV DNA.

Amniotic Fluid↗
PubMed1995

[Cystic retroperitoneal lymphangioma: a tumor of polymorphic clinical manifestations. Apropos of three cases].

BACKGROUND: Cystic retroperitoneal lymphangioma is a rare benign tumor with varied clinical presentation. CASE REPORTS: Case 1. A girl was born at term after ultrasonography had shown a cystic abdominal mass by 31 weeks of GA. This mass, clinically palpable at birth, was found again by ultrasonography. Surgical excision on day 3 was incomplete, requiring a second excision at the age of 2 months, followed by persistence of the cyst near the bladder; the patient was asymptomatic at the age of 2 years. Case 2. This full-term female newborn was admitted because of jaundice and pallor. Examination showed a firm mass of the left flank that was confirmed by X-rays and ultrasonography. Despite blood transfusion, anemia persisted, requiring surgery that showed a cystic hemorrhagic mass that was voided. A second partial excision was performed a few weeks later and, at the age of 7 months, ultrasonography showed a few small cystic masses behind the left kidney. Case 3. A 16-month-old boy was operated on for right inguinal hernia. The hernial sac contained fluid and its wall was thick. Ultrasonography and CT scan performed 3 days later were normal. The child was examined again 28 months later because he suffered from abdominal pain; a large mass was palpable in the right flank that appeared cystic at ultrasonography and CT scan. A retroperitoneal lymphangioma was completely excised. CONCLUSION: Because the risk of complications is apparently high, surgical treatment is always necessary. In the newborn period, complete excision is difficult, requiring delayed surgery.

Female↗
PubMed1995

[Prospective study of neonatal genital mycoplasma colonization and infection].

Genital mycoplasmas have been implicated in different neonatal diseases as pneumonia, sepsis and meningitis. This prospective study was conducted to specify their role in these diseases. POPULATION AND METHODS--A pharyngeal or tracheal swab specimen for mycoplasmas culture was obtained from 100 infants admitted consecutively to the Neonatal Care Unit (NCU) during the first 24 hours of life. Mycoplasma culture of blood and cerebrospinal fluid was also performed. Pharyngeal and/or tracheal specimens were collected again on days 5, 15 and 28 if the child was still in the NCU. Mycoplasma hominis (Mh) and Ureaplasma urealyticum (Uu) were identified by culture in a modified Hayflick's medium. RESULTS--Three-hundred and ten pharyngeal or tracheal swabs were obtained (100 on day 0, 89 on day 5, 72 on day 15 and 49 on day 28). Twenty-one infants had one or more positive swabs in the first five days of life (20 on day 0 and one on day 5); those forming the "Myco+" group and the others forming the "Myco-" group. Uu was isolated alone from 20 infants, associated with Mh from one. Both groups were similar for gestational age, birth weight, maternal fever during labor, prolonged rupture of the fetal membranes or chorioamnionitis and for the incidence of acute respiratory distress. There was a statistically significant difference for the route of delivery (chi 2 < 0.02). One blood culture (from 92 performed) was positive for Uu and another positive for Uu and Mh. Both children were cured without any specific mycoplasmacidal therapy. Three children had probable Uu infection and were also cured without specific therapy. CONCLUSIONS--A pharyngeal colonization with genital mycoplasmas is common in the first days of life (21%) but our data do not allow us to conclude that they are accountable for newborn infections.

Bacteremia↗
PubMed1995

[Myositis ossificans progressiva].

BACKGROUND: Myositis ossificans progressiva is a rare progressive disease of connective tissue with a poor prognosis. CASE REPORT: A 16 year-old girl suffered from lameness of her right leg associated with inguinal swelling. Progressive aggravation of pain with extension of swelling to the posterior part of her thigh required an X-ray examination which showed hip dysplasia and calcifications around the hip. Angiography was normal; a diagnosis of hematoma was suggested by scannography and bone scintigraphy, but biopsy showed features of nodular fasciitis. The association of progressive ectopic ossification to malformation of the big toe led to diagnosis of myositis ossificans progressiva. CONCLUSIONS: Congenital malformations, most commonly of big toes and thumbs, are important for distinguishing myositis ossificans progressiva from other diseases of muscle.

Adolescent↗
PubMed1995

Detection of respiratory syncytial virus by reverse transcription-PCR and hybridization with a DNA enzyme immunoassay.

Nasal aspirates from 238 infants hospitalized with acute respiratory infections during the winter of 1994 and 1995 were tested for respiratory syncytial virus (RSV) by immunofluorescence assay (IFA) and the viral isolation technique (VIT) and by two PCR and hybridization methods: reverse transcription PCR 1 (RT-PCR1), which amplifies the RNAs of all RSV strains, and RT-PCR-2, which allows subgroup classification of RSV. RT-PCR-1 and RT-PCR-2 detected viral sequences in 56.7% (135 of 238) and 48.3% (115 of 238) of the samples, respectively, while only 80 (33.6%) samples were found to be positive by IFA and VIT. Of the PCR-positive specimens, 57 were missed by these routine techniques in RT-PCR-1 and 45 were missed in RT-PCR-2. Although the RSV-PCR-1 and RSV-PCR-2 techniques amplified two different sequences of the RSV genome, they gave similar results for 218 (91.6%) nasal aspirates. Compared with conventional methods, the sensitivity, specificity, and agreement were 97.5, 63.9, and 75.2%, respectively, for RT-PCR-1 and 89.7, 71.9, and 77.7%, respectively, for RT-PCR-2, and for these two RT-PCR assays, the positive predictive value (PPV) and the index of agreement (kappa) were comparable and moderate, respectively: PPV was 57.8% and kappa was 0.52 in RT-PCR-1, and PPV was 60.9% and kappa was 0.54 in RT-PCR-2. However, there was a perfect correlation between the two RT-PCRs, with a PPV of 100% and an excellent index of agreement (kappa = 0.88). Therefore, most RT-PCR results were really true positive, and VIT and IFA, which missed some of them, appeared to be less sensitive.

Base Sequence↗
PubMed1994

[Virological diagnosis and treatment of respiratory syncytial virus infections].

Respiratory syncytial virus infections occur frequently in children, often localized in the upper respiratory tract. Outcome is usually quite satisfactory, but in nearly one half of the infants lower tract involvement may cause severe respiratory insufficiency leading to hospitalization in about 1% of the cases. Its frequency has been estimated at 20 to 30% of the viral infections in hospitalized infants, 10 times the frequency of the other respiratory virus. Respiratory syncytial epidemias last about 4 to 5 months with a seasonal peak in december and january. The direct detection of respiratory syncytial antigens in nasal specimens by immunofluorescence or enzymatic immunoassay is the key to rapid diagnosis. They appear as performant and more convenient than specific IgM antibodies or nucleic acid detections, and than virus isolation on cell culture, which is justified to evaluate strain sensitivity to ribavirin. Immunofluorescence has also been used to identify the subgroups A and B from 1981 to 1993, and respiratory syncytial subgroup A seems to signify more severe disease. Symptomatic assistance may require hydratation, oxygenotherapy and respiratory physical therapy. Antibiotics should not be given as a routine treatment since bacterial superinfection is infrequent, but may be indicated in cases with associated signs of complications. Indications for bronchodilators and corticosteroids are still under debate. Significant results have been obtained with ribavirin and specific anti respiratory syncytial immunoglobulins but further evaluations are still required to precise their use in clinical practice.

Antibodies, Viral↗
PubMed1994

Comparative study of four tests of bacterial infection in the neonate. Total neutrophil count, CRP, fibrinogen and C3d.

In a prospective study, the diagnostic value of C3d serum levels was compared with that of neutropenia, hyperfibrinogenemia and raised CRP in generalized neonatal bacterial infections. Serum C3d was evaluated using a counter-immunoelectrophoresis technique following a step of removal of C3 split products. Twelve patients with septicemia, 8 patients with highly probable infection and 134 normal controls were included in the study. The sensitivities for neutropenia, hyperfibrinogenemia, raised CRP and positive C3d were 21, 45, 60 and 70%, respectively, with a significant difference between the sensitivities of neutropenia and positive C3d (p < 0.01). The specificities were found to be 99.2, 99.2, 100 and 97.7% respectively. Thus the C3d qualitative test appears to be as reliable as CRP in the diagnosis of neonatal bacterial infections.

Bacterial Infections↗
PubMed1993

[Rehospitalization and early discharge in neonatology: retrospective evaluation].

This retrospective study compared discharge summary data in neonates discharged from the Brest Teaching Hospital Neonatology Unit between May 1, 1980 and April 30, 1981 (Period I) or between May 1, 1990 and April 30, 1991 (Period II). Birth weight, gestational age, duration of hospitalization, corrected age at discharge and rehospitalization rate were compared. Among infants with intrauterine growth retardation (IUGR) with or without prematurity, weight at discharge was 2,500 g or less in none of Period I patients (n = 144) versus 67.8% of Period II patients (n = 87). Four Period II infants weighted 2,000 g or less at discharge (1,850, 1,930, 1,960, and 2,000 g). Among premature infants without growth retardation, weight at discharge was 2,500 g or less in 2.2% of Period I infants versus 52.5% of Period II infants (p < 0.0001). Period II infants were not rehospitalized more often or earlier than Period I infants. Early discharge reduces the duration of separation of the child from his or her parents without increasing the rehospitalization rate.

Birth Weight↗
PubMed1992

Interspecies variations in caffeine metabolism related to cytochrome P4501A enzymes.

1. Interspecies (including man, monkey, rabbit, rat and mouse) variations in caffeine metabolism by liver microsomes were studied. While N-3 demethylation was the major pathway in man (81% of total dimethylxanthines), N-7 demethylation was predominant in monkey (89%), and the three demethylation pathways were about equal in mouse, rabbit and rat. 2. Three monooxygenase activities (methoxyresorufin O-demethylase, phenacetin O-deethylase and acetanilide 4-hydroxylase) correlated significantly with the rate of metabolism of caffeine. 3. P4501A1 and 1A2 enzymes were immunodetected in different species. P4501A2 was the only isoform detected in liver of man, rat and mouse, while no polypeptide immunorelated to P4501A was detected in monkey and only a minor band of P4501A1 was detected in rat and rabbit. 4. All in vitro data indicate that paraxanthine formation is mediated mainly by P4501A2 in mammals while theophylline formation is mediated mainly by cytochromes P-450 other than those of the 1A family.

Animals↗
PubMed1991

Evaluation of a screening test for detecting urinary tract infection in newborns and infants.

The results of a study of a screening test for urinary tract infection (UTI) in infants under 18 months is reported. Two hundred and forty three urine specimens were tested in the laboratory using AMES Multistix 8SG reagent strips read by photometer. The strips included three potential markers for urinary tract infection: leucocyte esterase, nitrite, and protein. The predictive value of a positive result (PPV) was low. The predictive value of negative test (NPV) when combining the screen of leucocyte esterase, nitrite, and protein was 99.4% with no difference between boys and girls. The test for leucocyte esterase had a 97.6% negative predictive value. An examination of the results by age confirms the good NPV in all age groups. Paediatricians should find Multistix 8SG strips a useful aid in the diagnosis of urinary tract infection in infants, and that costly culture of samples with negative strip tests can be avoided.

Humans↗