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M Vanhove

Publications and source records attributed to M Vanhove.

22 records · Page 2Linked to original sources
PubMed1995

Stability of TEM beta-lactamase mutants hydrolyzing third generation cephalosporins.

The stability properties of six natural mutants of the TEM-1 beta-lactamase have been studied. The glutamate to lysine substitution at positions 104 and 240 stabilize the enzyme. Conversely, the G238S mutant's decreased stability might reflect an altered conformation of the active site and thus be related to the modified substrate profile. The relative stability of the R164S and R164H mutants is explained by the formation of a hydrogen bond between these residues and Asp-179 conferring a somewhat different structure to the omega loop and thus also explaining the extended substrate profile of these mutants. The loss of stability of the R164H mutant with increasing pH values can be explained by the titration of a hydrogen bond between the N delta of His-164 and the O delta of Asp-179. The properties of the G238S + E104K double mutant which is the most active against third-generation cephalosporins result from a balance of destabilizing and stabilizing substitutions, and their effects seem to be additive. The behavior of the R164S + E240K mutant might be explained on the basis of a similar compensation phenomenon.

Arginine↗
PubMed1995

Serial cardiorespiratory exercise testing in patients with congenital heart disease.

Aerobic capacity of patients with different forms of congenital heart disease was serially evaluated in 79 patients and the evolution was correlated with the lesion and the level of daily activity. The patients were divided into six groups: patients with a small ventricular septal defect (VSD) with mini shunt (n = 14), mild pulmonary valve stenosis with gradient < 40 mm Hg (PS) (n = 12), mild to moderate aortic valve stenosis (gradient 36 +/- 17 mmHg) (AS) (n = 12), patients 4.7 +/- 2.1 years after repair of tetralogy of Fallot (PO-TF) (n = 16), patients 2.2 +/- 2.9 years after closure of a high flow/high gradient VSD (PO-VSD) (n = 13), and patients 2.6 +/- 1.7 years after Fontan repair (Fontan-PO) (n = 12). Aerobic capacity was assessed by determination of the ventilatory anaerobic threshold (VAT). VAT reflects the highest aerobic exercise level prior to a disproportionate increase of CO2 and ventilation relative to O2 uptake; it is independent of patient motivation. Data are expressed as percentage of normal O2 uptake at VAT, determined in 234 age/gender matched controls. The habitual level of physical activity was assessed by a standardised questionnaire. Aerobic capacity in all subgroups of patients, even with very mild defects, was at or below the lower limit of normal. Children left unrestricted from physical exercise (VSD, PS, PO-VSD) had no change over the study period. However, aerobic capacity of patients with medically imposed physical restrictions (AS) and significant residual haemodynamic lesions (PO-TF, Fontan) decreased with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Benign stomach tumors: histology, diagnosis and surgical experience].

Benign neoplasms of the stomach lead to atypical symptoms. Radiological and endoscopic investigations are always recommended. Our surgical experience with 11 epithelial and 26 mesenchymal benign neoplasms is discussed. A local excision could be carried out in 24 patients, of whom 4 developed postoperative complications and one deceased. Ten cases required a partial and 3 cases a total gastrectomy. This was mainly due to the localisation or the extent of the lesions. One surgical complication occurred and one patient died. Relapse was never observed in the long-term (i.e. 6 years) follow-up of 29 patients. Nonetheless, a yearly radiological or endoscopical control is advocated since hyperplastic polyps can relapse as exaggerated healing of an ulcer, and because especially leiomyomas, neurilemmomas en lipomas carry a substantial risk of malignant degeneration.

Adolescent↗