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Biomedical subjects

F Bernard

Publications and source records attributed to F Bernard.

At least 109 records · Page 6Linked to original sources
PubMed1990

Reconstituted skin in culture: a simple method with optimal differentiation.

Human skin is a unique organ, which can be reconstituted in vitro and represents an interesting system for studying cell proliferation and differentiation. A simple technique for producing reconstituted skin with optimal epidermal differentiation is described and characterized. A 4-mm punch biopsy of normal human skin is deposited on the epidermal side of mortified de-epidermized human dermis maintained at the air-liquid interface with a metallic support. The culture medium contains insulin, epidermal growth factor (EGF), cholera toxin, hydrocortisone, penicillin/streptomycin and fungizone. A well-differentiated epidermis develops within 15 days. Morphological and ultrastructural studies show a neoepidermis resembling normal skin. Differentiation markers such as involucrin, filaggrin, and various cytokeratins detected with pancytokeratin antibody are present and confirm this resemblance. The keratin profile is comparable to that observed in other skin culture models. A basement-membrane-like structure is reconstituted with hemidesmosomes and anchoring-filament formation. Bullous pemphigoid (BP) antigen is observed at the dermo-epidermal junction after 21 days of culture. Moreover, both dermal substrates and punch biopsies can be kept frozen for long-term storage, with little or no loss of epidermal growth kinetics and morphology. This skin culture technique is rapid, simple, economical and reproducible. Characterization has here shown high-quality epidermal differentiation. Scientists interested in epidermal in vitro studies should take interest in all these advantages.

Antibodies, Monoclonal↗
PubMed1990

[Development of a safe technique for central venous access in pediatrics. Our experience with 700 percutaneous central catheters].

Since 1977, the authors have performed 708 percutaneous catheterizations of superior vena cava in pediatric patients (from premature infant of 15 year old children). The greater part of these catheterizations concerns the internal jugular vein. Subclavian catheterization was rapidly abandoned because it is judged too dangerous in children. The evolution of the quality of materials, and the increasing technical experience of operators, both allowed to enlarge indications of percutaneous catheterization. That suppose a nearly total suppression of mechanical and infectious complications. The analysis of 7 severe vascular injuries in 445 patients made the authors change their technics and apply a very strict method: choice of a frontal access to internal jugular vein; catheterization performed in operating room, under anesthesia; percutaneous puncture with a lew diameter short catheter (external diameter: 9/10 mm); Seldinger technic and radioscopy; silicone catheters with or without a cuff, systematic tunellisation; operators having a very good practice of venous access in children. The analysis of the three last years shows no immediate mechanical complication and very little infections among 263 catheterizations.

Adolescent↗
PubMed1990

Gastroesophageal reflux and upper airway diseases.

GER can have important impacts on the upper airway passages, and in turn, upper airway obstruction can certainly aggravate reflux. This relationship should be considered in the newborn or young infant, faced with a sudden life-threatening event, and in the older child or adult presenting with chronic head and neck complaints, either unexplained or unresponsive to adequate medical therapy. A causal relationship may be difficult to establish, based first on clinical expertise as a guideline, on laboratory tests, among which pharyngeal pH monitoring could be promising, and on response to medical antireflux therapy. A better understanding of the significance of high levels of reflux and defective acid clearance, as well as a more precise knowledge of the maturation and functioning of upper airway protective mechanisms, would open the way to more accurate diagnostic procedures, to a more reliable definition of the abnormal, and to greater efficiency in the management of these patients.

Gastroesophageal Reflux↗
PubMed1990

[Minimal lipid anomalies in a group of men with early coronary disease compared to a control group].

A group of 27 men with early coronary disease (mean age: 52 years) with cholesterol levels below 6.45 mmol/l and triglycerides levels below 2.3 mmol/l, who underwent a coronary angiography, is compared with a control group of 18 men (CG) with normal angiography. The only significant differences between the two groups are: a triglycerides levels slightly higher in the CM group (1.55 + 0.4 mmol/l) vs 1.18 +/- 0.37 mmol/l, p 0.001), a HDL-cholesterol level slightly lower in the CM group (1.08 +/- 0.19 mmol/l vs 1.26 +/- 0.21 mmol/l, p 0.01) and an Apo AI/Apo B ratio slightly lower in the CM group (1.02 +/- 0.24 vs 1.18 +/- 0.17, p 0.005). In the CM group, 21 patients in 27 present a lipid abnormality requiring, according to the European consensus recommendations, the prescription of hygieno-dietetic measures. In the CM group, 10 patients in 18 present a minimal lipid abnormality, also requiring hygieno-dietetic measures. These results are compared with the recommendations of the European consensus.

Coronary Disease↗
PubMed1989

Purification and identification of a neutral endopeptidase in Plasmodium falciparum schizonts and merozoites.

An endopeptidase specific to the Plasmodium falciparum erythrocytic schizont stage and to free merozoites was detected using the fluorogenic GlcA-Val-Leu-Gly-Lys(or Arg)-AEC substrate. The enzyme was purified by high performance liquid chromatography (HPLC); its optimal activity was around pH 7.5 and its isoelectric point was 4.4. The molecular weight of the enzyme was about 68,000, as demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions. The endopeptidase was strongly inhibited by thiol proteinase inhibitors, leupeptin, and antipain. The possible involvement of this neutral endopeptidase in the reinvasion process is discussed.

Animals↗
PubMed1989

Relationship between virulence of Chlamydia psittaci strains and establishment of persistent infection of McCoy cells.

The pathogenicity of chlamydial strains for their natural hosts and their ability to induce persistent infections in McCoy cells were compared. Both virulent and avirulent strains persistently infected McCoy cells, but the appearance of the cell culture varied between strains. Avirulent strains induced completely inapparent persistent infection (infection Type 1), while with invasive strains the culture alternated between periods of cell multiplication and periods of extensive cytopathic change (infection Type 2). The virulence of virulent strains was not attenuated, even after 6 months of culture, but after 2 or 3 months some avirulent strains produced infection Type 2 and became invasive for mice and abortive for ewes. This variation of virulence was accompanied by a modification of protein patterns.

Abortion, Veterinary↗
PubMed1989

[Vascular injuries during percutaneous catheterization of the lower neck in children].

Four cases of vascular injuries of subclavian artery in children are reported after 414 percutaneous catheterization between 1980 and 1986. The first case reported is a 2 month old child with a right subclavian aneurysm after punction, witch be treated by a successful resection-anastomosis. Three others children, 12, 13, and 14 years old have been catheterized by a jugular approach for one and by a subclavian approach in the others. In this three cases the diagnosis was made by an important hemothorax requiring a drainage. In one case, the recovery was obtain only by drainage, in the two others a surgical approach was necessary with a suture of the subclavian artery in one and a ligation in the other case. The diagnosis of these vascular lesion is difficult = an hemothorax must be drained quickly and a persistent bleeding require a surgical treatment by a cervical route associated with a cleidotomy for the subclavian control. All catheterization in children must be realized by operator with a good practice and an adapted material. The jugular route must be preferred to the subclavian route in children.

Adolescent↗
PubMed1989

Mouse models for evaluation of virulence of Chlamydia psittaci isolated from ruminants.

Intestinal strains of Chlamydia psittaci isolated from faeces of clinically healthy sheep or goats were differentiated from pathogenic strains isolated from animals affected with chlamydial diseases by their virulence in mice. The invasiveness of strains after footpad inoculation was estimated in non-pregnant mice by recording the colonisation and the enlargement of the spleen on days 6 and 9 after inoculation. The abortifacient effect was judged by measuring the colonisation of placenta and fetuses of pregnant mice inoculated intravenously on day 11 +/- 1 of pregnancy. While 25 of 27 pathogenic strains were invasive and able to colonise placenta and fetuses, eight of 10 intestinal strains were not. The model permits graded differentiation between virulent and non-virulent strains and suggests that in propitious circumstances intestinal chlamydia could reach and colonise the placenta and disturb the pregnancy.

Animals↗
PubMed1987

Plasmodium berghei and Plasmodium chabaudi: a neutral endopeptidase in parasite extracts and plasma of infected animals.

By using a sensitive fluorometric method with Val-Leu-Gly-Arg-3-amino-9-ethylcarbazole (VLGR-AEC) as a substrate, two endopeptidase activities were identified in two fractions of Sephacryl S-200 gel filtration from soluble P. berghei and P. chabaudi extracts. Controls with normal mouse erythrocytes, with leukocytes, and with reticulocyte enriched blood and different washing procedures during the preparation of soluble P. berghei extracts showed that the MW greater than 200 kDa fraction was a contaminant from erythrocytes and exhibited an optimal pH activity of 8.2. In contrast, the fraction 130 kDa was related to P. berghei and P. chabaudi and exhibited an optimal pH activity of 7.4. The two enzyme activities were compared with eight different substrates. The parasite endopeptidase showed a strong activity with Val-Leu-Gly-Lys-AEC (VLGK-AEC) and Ser-Gly-Lys-AEC (SGK-AEC) as substrates; in contrast, the mouse host endopeptidase poorly cleaved the VLGK-AEC and did not cleave SGK-AEC. Presence of the hydrophobic benzyl group on serine reduced the hydrolizing properties of P. berghei endopeptidase: the reverse was observed with host endopeptidase. The hydrolysis of the N-polyhydroxyalcanoyl-VLGK-AEC substrate by the parasite neutral endopeptidase strongly increased with the schizogonic stage, as shown with synchronized P. chabaudi in mice. By its physiological pH and specificity the release of this enzyme in mouse plasma during the infection could be of interest in a peptidyl-drug strategy.

Animals↗
PubMed1987

Purification of a Plasmodium berghei neutral endopeptidase and its localization in merozoite.

A Plasmodium berghei neutral endopeptidase specific for the fluorogenic substrates valyl-leucyl-glycyl-arginyl/lysyl-aminoethyl-carbazole was purified by Fast Protein Liquid Chromatography. The enzyme was a Mr 68,000 polypeptide. Immunization of mice with the purified enzyme gave a specific antiserum, as demonstrated by immunoblotting. Immunofluorescence with this antiserum showed a strong labelling of P. berghei merozoites in mature segmented schizonts and of merozoites released from schizont-infected red blood cell. This labelling was mainly associated with the merozoite apex. It is possible that this endopeptidase is involved in the reinvasion.

Animals↗
PubMed1987

Simultaneous vaccination by three living attenuated strains of Brucella, Salmonella and Chlamydia in mice.

Associations of vaccines for simultaneous administration were successfully developed long ago, in particular in human medicine, although there have been very few attempts to associate living bacterial vaccines. Unfortunately, living vaccines can interact with one another resulting in either a virulent infection or an exclusion of one by the other. Having developed two new low virulence vaccinal strains of Chlamydia psittaci var. ovis and Salmonella abortus ovis for use in veterinary medicine, we studied associations of both and with the Brucella melitensis Rev1 vaccine in mice. There was no interaction between the Chlamydia and the Salmonella vaccines and between the Salmonella and the Brucella vaccines from the point of view of immunogenicity. In contrast, anti-Chlamydia immunity was decreased by about 15-19% when the Chlamydia vaccine was associated with the Brucella vaccine in double or triple association. Surprisingly, the Chlamydia vaccinal strain infection was slightly extended when administered in association. The simultaneous vaccination we tested could be of great interest in veterinary medicine, but special attention must be devoted to anti-Chlamydia immunity and would have to be studied in a ewe model.

Animals↗
PubMed1987

Comparison of once and twice daily administration of captopril plus hydrochlorothiazide on 24 h blood pressure levels.

The anti-hypertensive effect of captopril 50 mg plus hydrochlorothiazide 25 mg, given once or twice daily, was investigated by 24 h monitoring in hypertensive patients in a controlled, randomized, double-blind, cross-over trial. Ten patients with blood pressure (BP) greater than 160 and/or 95 mm Hg after a 15 day placebo period, were randomly assigned to one of two treatments, in which they either received the combination once daily in the first month, twice daily in the second and once daily in the third (Treatment Group A) or twice daily in the first month, once daily in the second month and twice daily in the third month (Treatment Group B). The anti-hypertensive effect of the drug combination was assessed by 24 h monitoring using a Dinamap 845 to establish mean BP levels and circadian curves. After 1 month the twice daily administration was more effective than the once daily, but after 2 months, and throughout the third month, there was no difference in the anti-hypertensive efficacy of the combination given either once or twice daily.

Blood Pressure↗
PubMed1987

[Antihypertensive therapeutic effect. Comparison of their evaluation using clinical and ambulatory measurements of arterial pressure. Preliminary study].

The aim of this preliminary report is to compare the evaluation of the antihypertensive drug effect, during a controlled trial, using casual measurements and 24 hr B.P. monitoring. 20 patients (16 males, 4 females 55 +/- 10 years old) with primary hypertension (WHO stage I or II) were included with a diastolic blood pressure greater than or equal to 100 mmHg (mean blood pressure from three clinical readings). Casual B.P. and B.P. monitoring (Spacelabs - 4 measurements per hour during a 24 hr period) were established before and after the end of the placebo run in period (one placebo tablet given once daily at 8 h-8 h 30 a.m. for 15 days). Overall sample data: The clinical B.P. decrease (167 +/- 16-109 +/- 7 before and 147 +/- 17-97 +/- 11 after treatment) is higher that the ambulatory B.P. decrease (148 +/- 15-101 +/- 8 before and 138 +/- 21-94 +/- 14 after treatment). Individual patient data: A clinical B.P. decrease (of at least 10 mmHg) was found in 17 patients for systolic B.P. and in 15 patients for diastolic B.P. A significant ambulatory B. P. drop decrease (p less than 0.05) was found in 11 patients for 24 hr systolic and diastolic B.P. The clinical and ambulatory responses to the treatment are in line in 14 patients, but differ in 3 instances. There is a little correlation (for the diastolic B.P.) and no correlation (for the systolic B.P.) between the clinical and the ambulatory B.P. decreases after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Study of the placebo effect in using the non-invasive ambulatory measurement of blood pressure].

The aim of this study is to evaluate the antihypertensive effect of placebo assessed by 24 hr non invasive blood pressure monitoring. 20 patients (16 males, 4 females, 55 +/- 10 years old) with primary hypertension (WHO stage I or II) were included with a diastolic blood pressure greater than or equal to 100 mmHg (mean blood pressure from three clinical readings). Casual blood pressure and blood pressure monitoring (Spacelabs - 4 measurements per hour during a 24 hr period) were established before and at the end of the placebo run in period (one placebo tablet given once daily at 8 h-8 h 30 a.m. for 15 days). Overall sample data: There was no antihypertensive effect of the placebo with casual BP (167 +/- 16-109 +/- 6 mmHg before and 167 +/- 16-109 +/- 7 mmHg after placebo) and with 24 hr B.P. monitoring (142 +/- 14-96 +/- 8 mmHg before and 141 +/- 14-96 +/- 8 mmHg after placebo). The circadian curves were similar. Individual patient data: A clinical placebo effect (B.P. decrease of at least 10 mmHg) was found in 5 patients for the systolic B.P. and in 2 for diastolic B.P. A significant ambulatory placebo effect (p less than 0.05) was found in 5 patients for the 24 hr systolic B.P. and in 4 patients for the 24 hr diastolic B.P. However, patients with clinical placebo effect were not the same as those with ambulatory placebo effect. There was no correlation between the clinical and the ambulatory response to placebo treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[A case of acute gastric volvulus in a newborn infant].

Gastric volvulus is a rare cause of respiratory distress and vomiting in neonates. This diagnosis was suspected in a 4 week old baby with acute respiratory distress accompanied with vomiting, from the results of an esophagogastroduodenal radiological examination. At operation a gastric volvulus was confirmed, associated with an anatomical malformation: absence of gastrosplenic omentum predisposing to gastric volvulus with mesenterio-axial rotation. Gastropexy was followed by an uncomplicated postoperative course. A literature review confirmed rarity of this affection and raised the problem of causes of repeated vomiting in the newborn and premature infant. An often incriminated lesion is gastric plicature, a radiological notion, whereas gastric volvulus is accompanied necessarily by an altered uptake of contrast in the stomach. Acute volvulus must be distinguished from other types of volvulus, notably that observed during hiatus hernia. Early diagnosis allows rapid surgical treatment by anterior gastropexy as recommended by most authors.

Acute Disease↗
PubMed1986

Surface Plasmodium sugar-binding components evidenced by fluorescent neoglycoproteins.

A sugar-binding component was shown to be present at the surface of endoerythrocytic Plasmodium berghei and P. chabaudi stages and merozoites by means of a panel of neoglycoproteins using fluorescence microscopy and flow cytofluorometry. The protein nature of this material was ascertained by the loss of sugar-binding capacity upon trypsin treatment. This lectin-like protein primarily bound neoglycoprotein-borne N-acetylglucosamine and secondarily bound neoglycoprotein-borne alpha-D-glucose, beta-D-galactose and alpha-L-fucose. These results suggest the presence of at least one type of lectin-like protein with an extended binding site accomodating several sugar units, and define its localization on the parasite surface.

Animals↗
PubMed1986

[Ambulatory recording of blood pressure. Study of the reproducibility of findings in 25 subjects].

The reproducibility of a novel ambulatory blood pressure (B.P.) monitoring was tested, for clinical trial in hypertension. The spacelabs apparatus is based on standard auscultatory and oscillometric blood pressure measurements. Ten normotensive patients and 15 hypertensive patients were investigated as follows: their blood pressure was monitored twice over a 24 hr period at an interval of 30 and 15 days respectively. The monitoring data were expressed as the mean of the average blood pressure over day-time (7 hr-22 hr) and 24 hr as well as 24 hr. B.P. profiles (means of 4 measurements per hour). The statistical analysis of the two subpopulations of patients showed a satisfaction reproducibility of both the 24 hr B.P. curves (normotensive patients: PAS: r = 0.94; PAD: r = 0.92; Hypertensive patients PAS: r = 0.82; PAD: r = 0.64 p less than 0.001). and blood pressure levels (normotensive patients: J1: 113 +/- 10/70 +/- 6 mmHg; J30: 110 +/- 10/68 +/- 6 mmHg. Hypertensive patients: J1: 150 +/- 10/98 +/- 9 mmHg; J15: 155 +/- 15/96 +/- 8 mmHg). In contrast, analyzing each patient individually exhibited a correct reproducibility of the B.P. levels but the 24 hr--profiles of either the diastolic or systolic blood pressure could not be correlated with sufficient reliability (normotensive patients: 7 times out of 10 for PAS, and 4 times out of 10 for PAD; hypertensive patients: 5 times out of 15 for PAS, and 3 times out of 15 for PAD). In addition, the patient activity, should be carefully controlled during ambulatory blood pressure measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗