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Biomedical subjects

A Lamarre

Publications and source records attributed to A Lamarre.

At least 37 records · Page 2Linked to original sources
PubMed1991

Antiidiotypic vaccination against murine coronavirus infection.

Rabbit polyclonal antiidiotypic antibodies were generated against a neutralizing mAb specific for a conformational epitope on the S glycoprotein of murine hepatitis virus, strain A59 (MHV-A59). These anti-Id were directed predominantly against an Id that was undetectable in rabbit and rat anti-MHV-A59 sera and weakly represented in syngeneic and allogeneic antiviral sera. However, some partial idiotypic sharing was observed between the Id-bearing antibody and a mAb with a similar antigenic site specificity. The anti-Id inhibited the virus-binding and neutralizing activities of the immunizing antibody, demonstrating that they recognize paratope-associated idiotopes. Mice immunized with affinity-purified anti-Id developed MHV-A59-specific antibodies that neutralized viral infectivity to high titers. Moreover, these animals survived an otherwise lethal challenge with viral murine hepatitis virus, unlike control mice immunized with normal rabbit Ig. These results indicate that at least a subpopulation of the polyclonal anti-Id could induce a protective immune response directed toward a biologically important MHV-A59 epitope, and demonstrate the feasibility of antiidiotypic vaccination against a coronavirus infection.

Animals↗
PubMed1991

Taurine decreases fecal fatty acid and sterol excretion in cystic fibrosis. A randomized double-blind trial.

Patients with cystic fibrosis may still have a significant degree of steatorrhea despite adequate pancreatic enzyme supplementation. Taurine is a conditionally essential amino acid that possibly improves the micellar phase of fat digestion. Thirteen children with cystic fibrosis and a significant degree of steatorrhea (> 13 g/d) were enrolled in a randomized double-blind crossover study of taurine (30 mg/kg per day) in contrast to placebo for two successive 4-month periods. No difference was noted in height and weight velocity, lung function, vitamin A level, and essential fatty acid status. Twelve of the 13 patients showed a decrease in fecal fatty acid excretion (26.5 +/- 2.6 g/24 h vs 15.4 +/- 2.5 g/24 h), affecting mainly saturates and monounsaturates, and a decrease in total sterol excretion (1492.6 +/- 303 mg/24 h vs 1211.7 +/- 213.8 mg/24 h) while ingesting taurine. Taurine may be a useful adjunct in patients with cystic fibrosis and severe steatorrhea.

Adolescent↗
PubMed1989

Comparison of cardiovascular adjustments to exercise in adolescents 8 to 15 years of age after correction of tetralogy of fallot, ventricular septal defect or atrial septal defect.

Surgical correction of tetralogy of Fallot (TF) has generally been associated with a reduced maximal exercise tolerance, possibly related to the ventriculotomy inherent to the intracardiac repair procedure. This study documents the exercise hemodynamics of a group of patients operated on for TF who showed similar clinical and functional characteristics, and compares these responses to those of age-matched patients operated on for an isolated ventricular septal defect (VSD) or atrial septal defect (ASD) in an attempt to better understand the role of the ventriculotomy in the exercise limitation. Thirty patients, ages 12 to 19 years, operated on before 5 years of age for complete repair of TF (n = 13), VSD (n = 7) or ASD (n = 10) and 10 age-matched control subjects underwent a progressive maximal cycling test to determine the maximal oxygen uptake (VO2 max), and completed submaximal cycling at intensities of 33 and 66% VO2 max, respectively, to determine the cardiac output (CO2-rebreathing). No significant differences in VO2 max were observed (TF = 37.6 +/- 10; VDS = 34.0 +/- 9.2; ASD = 36.5 +/- 7; controls = 41.3 +/- 6.0 ml/kg/min). The maximal heart rate, however, remained lower in all patient groups in comparison with control subjects (p less than or equal to 0.05) (TF = 178 +/- 14; VSD = 172 +/- 17; ASD = 179 +/- 16; controls = 191 +/- 12 beats/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1989

Effect of pH and temperature on the infectivity of human coronavirus 229E.

The stability of human coronavirus 229E infectivity was maximum at pH 6.0 when incubated at either 4 or 33 degrees C. However, the influence of pH was more pronounced at 33 degrees C. Viral infectivity was completely lost after a 14-day incubation period at 22, 33, or 37 degrees C but remained relatively constant at 4 degrees C for the same length of time. Finally, the infectious titer did not show any significant reduction when subjected to 25 cycles of thawing and freezing. These studies will contribute to optimize virus growth and storage conditions, which will facilitate the molecular characterization of this important pathogen.

Cells, Cultured↗
PubMed1989

Circulating immune complexes, antibodies to Pseudomonas aeruginosa, and pulmonary status in cystic fibrosis.

Serum samples from 37 patients with cystic fibrosis (CF), whose lungs were colonized by Pseudomonas aeruginosa, were tested in a 1 yr prospective study to examine a possible relationship between levels of circulating immune complexes (CIC) and the following parameters: level of specific antibodies to P. aeruginosa; relative importance of P. aeruginosa mucoid and non-mucoid strains isolated from sputum; the forced expiratory volume (FEV1; percentage predicted); the chest X-Ray score (Brasfield system) and the clinical score (Shwachman system). Reactivity of CIC against P. aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Escherichia coli antigens were also assayed. We found that the FEV1, the chest X-Ray and the clinical scores were significantly lower in patients with high levels of CIC than in those with normal levels of CIC (p less than 0.001 for each). We also found that the level of IgG antibodies against P. aeruginosa was significantly higher (p less than 0.001) in patients with high levels of CIC than in those with normal levels of CIC. 78% of patients with high levels of CIC had predominantly mucoid P. aeruginosa isolates whereas only 21% of patients with normal levels of CIC had also predominantly mucoid P. aeruginosa isolates. Specific antibodies to P. aeruginosa were detected in all CIC isolated by polyethylene glycol precipitations from CF patients exhibiting both high levels of CIC and inferior pulmonary status. Our findings support the hypothesis that a high level of CIC in association with an aggressive humoral response to P. aeruginosa correlates with defective pulmonary status in cystic fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Individualized aminoglycoside dosage regimens in patients with cystic fibrosis.

Individualized dosage regimens have recently been recommended for patients treated with aminoglycoside antibiotics. We have developed a calculator-based program for our patients with cystic fibrosis and have studied 93 courses of intravenous aminoglycoside treatment, comparing predicted and measured values in 45 courses. Pharmacokinetic parameters differed notably among subjects: this was reflected by widely variable total daily aminoglycoside dosage requirements. The mean daily dosage requirements (+/- SD) for tobramycin (62 treatment courses) was 13.0 +/- 3.74 mg/kg, and for gentamicin (26 treatment courses) was 11.5 +/- 2.6 mg/kg. The accuracy of the program was evaluated by its ability to predict peak and trough values in individuals: 84 percent of measured peaks were within 2 micrograms/ml of the predicted level. Nephrotoxicity was observed in one patient, ototoxicity in three. This program provides a simple, safe, and effective method of tailoring an aminoglycoside regimen to the patient's needs.

Adolescent↗
PubMed1987

Diffusion capacity and oxygen desaturation effects on exercise in patients with cystic fibrosis.

Although a fall in arterial oxygen saturation (SaO2) during exercise has been reported in patients with advanced lung disease due to cystic fibrosis (CF), not every patient with advanced disease desaturates, and pulmonary function tests have not been considered predictive as to which patient will desaturate. This study evaluated oxygen desaturation by ear oximetry during a progressive exercise test in 21 patients with CF and compared it to forced expiratory volume in one second (FEV1), the forced vital capacity (FVC) and the single breath diffusing capacity for carbon monoxide (DCO), all expressed as percent predicted. During exercise, the SaO2 fell less than 0.25 percent per ml of the maximal O2 consumption per kilogram of body weight to values never less than 90 percent in 15 patients (group A), whereas it fell more than this and always to values at the end of exercise of less than 90 percent in six others (group B). The FEV1 ranged from 103 percent predicted to 37 percent for group A compared to 28 to 17 percent in group B, while the range of FEV1/FVC was 87 to 52 percent for group A and 54 to 40 percent for group B. The range of DCO for group A was 129 to 84 percent compared to 64 to 54 percent. In conclusion, this study found that both the FEV1 and the DCO could separate those that had significant desaturation from those that did not and that no patient with a DCO of 80 percent or greater had significant desaturation during exercise.

Adolescent↗
PubMed1987

Histamine challenge test in children using forced oscillation to measure total respiratory resistance.

This study analyzed the relationship between total respiratory resistance (Rrs) measured by forced oscillation technique and FEV1 during histamine provocation test in 31 children between seven and 17 years of age. Rrs was measured at frequencies between 6 (R6) and 26 Hz (R26). (R6-R26)/R26 was used as an index of frequency dependency of Rrs. A positive histamine test was defined as PC20 less than 8 mg/ml. Seventeen subjects had a positive test, and all of these had increases from baseline of R6 greater than 50 percent and (R6-R26)/R26 greater than 0.45. Of the 14 subjects whose PC20 was greater than 8 mg/ml, only two had changes in R6 and (R6-R26)/R26 of this magnitude. These two subjects had changes in FEV1 of 16 and 18 percent. There was a strong linear relationship between the changes in FEV1 and both R6 and (R6-R26)/R26 from baseline to the final value at the end of the test (r = 0.87 and 0.91 respectively). In conclusion, this study demonstrated that the evaluation of airway reactivity by histamine challenge may be done by forced oscillation technique. It is easy to administer and may allow testing of children unable to perform spirometry.

Adolescent↗
PubMed1986

Group A streptococcal supraglottitis.

We describe four children with severe supraglottic infections caused by group A beta-hemolytic streptococci. In each case the clinical presentation suggested Hemophilus influenzae epiglottitis. In only one patient was there significant involvement of the epiglottis, whereas all had striking inflammation of the aryepiglottic folds. Group A beta-hemolytic streptococcus was isolated in blood cultures in two patients and from the supraglottic area and trachea in two others. Fever persisted for 6 to 22 days, and tracheal intubation was necessary for 2 to 16 days, despite appropriate antibiotic therapy. The evolution of streptococcal supraglottitis may be protracted, and it must be managed accordingly.

Child↗
PubMed1986

Psychomaintenance of childhood asthma: a study of 34 children.

Following the study on psychomaintenance of asthma by Kinsman, Dirks, and Jones (1977), we adapted the Battery for Asthma Illness Behavior (BAIB) to children. Thirty-four children aged 9.3 to 15.4 years were tested with this modified BAIB. They were scored simultaneously on a semistructured psychological interview. Three groups emerged out of these data: low-, medium-, and high-panic-fear personalities. Patients were also rated with regard to their pulmonary function and clinical status, including medication prescribed. The high-panic-fear personality was significantly associated with a higher intensity of prescribed medication, in particular corticosteroids. These results were independent of spirometric pulmonary measurements. We conclude that doctors may overreact to the exaggerated distress of high-panic-fear patients. Psychotherapy could be of help for this group.

Adolescent↗
PubMed1985

[Bronchogenic cysts of the mediastinum in children. Apropos of 14 cases].

Fourteen children, aged from 2 months to 14 years, underwent surgical excision of a bronchogenic cyst in the mediastinum. Nine of these children were asymptomatic and the finding of the tumor was purely accidental. Retrotracheal and subcarinal localizations were more often symptomatic but their visualization on standard chest roentgenograms was sometimes difficult. An oesophagogram was helpful for the diagnosis in those circumstances. No postoperative complication occurred in our series.

Adolescent↗
PubMed1985

[Subpleural lipoma in children].

Primary extrapleural intrathoracic tumors are extremely rare in the pediatric patient. The authors report one observation of intrathoracic subpleural lipoma in five-year-old asymptomatic girl. A thoracic CT-Scan was particularly helpful by demonstrating the homogeneous fatty nature of the mass, the density of-120 Hounsfield Units being specific. This allowed us to limit ourselves to a brief non-invasive diagnostic workup. Complete surgical excision is curative and provides histological certainty about the benign nature of the tumour. It remains the current recommended approach.

Child, Preschool↗