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Biomedical subjects

G François

Publications and source records attributed to G François.

At least 19 recordsLinked to original sources

Preliminary analysis of the resources in brachytherapy in Europe and its variability of use.

PURPOSE: The main objective of the program < > is to establish a group with detailed information on brachytherapy throughout Europe. METHODS: The data was compiled by the general coordinator, the ESTRO, and the < > through a website. RESULTS: A total of 32 countries reported data from at least 50% of their centres (criteria of inclusion). Countries were grouped in three categories based on the time of incorporation to the European Union. The majority of treatments belonged to gynaecological tumours. A large spread was found regarding workload of specialists depending on centre and group. CONCLUSION: Collection of information by a website is a feasible methodology. An increase in brachytherapy treatment was observed in all 3 groups by a rate of more than 20% (year 2002 versus year 1997). These results advocate for the continuation of the PCBE study to demonstrate the development in the field, such as an increase or decrease of patient numbers per tumour category.

Brachytherapy↗

Hepatitis B virus and human immunodeficiency virus co-infection in sub-Saharan Africa: a call for further investigation.

A growing body of evidence indicates that human immunodeficiency virus (HIV)-positive individuals are more likely to be infected with hepatitis B virus (HBV) than HIV-negative individuals, possibly as a result of shared risk factors. There is also evidence that HIV-positive individuals who are subsequently infected with HBV are more likely to become HBV chronic carriers, have a high HBV replication rate, and remain hepatitis Be antigen positive for a much longer period. In addition, it is evident that immunosuppression brought about by HIV infection may cause reactivation or reinfection in those previously exposed to HBV. Furthermore, HIV infection exacerbates liver disease in HBV co-infected individuals, and there is an even greater risk of liver disease when HIV and HBV co-infected patients are treated with highly active anti-retroviral therapy (HAART). Complicating matters further, there have been several reports linking HIV infection to 'sero-silent' HBV infections, which presents serious problems for diagnosis, prevention, and control. In sub-Saharan Africa, where both HIV and HBV are endemic, little is known about the burden of co-infection and the interaction between these two viruses. This paper reviews studies that have investigated HIV and HBV co-infection in sub-Saharan Africa, against a backdrop of what is currently known about the interactions between these two viruses.

AIDS-Related Opportunistic Infections↗

Hepatitis B surface antigenaemia following vaccination with a combined vaccine against hepatitis A and B.

We report a case of transient hepatitis B surface antigenaemia (HBsAg) following vaccination with a combined vaccine against hepatitis A and B in healthy adults. This phenomenon has been observed following administration of recombinant hepatitis B (monovalent) vaccine, mainly in newborns or dialysis patients. Reports on healthy adults are much less frequent and mostly concern blood donors. The frequency of its occurrence is largely unknown but its duration does not exceed 28 days. It is not detected by all available assays. It is caused by a passive transfer of antigen by vaccination, and not by viral replication; hence there is no risk for vaccination-induced infection. An important implication resulting from our findings is that the results of HBsAg assays should be interpreted according to the time elapsed since the last administration of a recombinant monovalent vaccine against hepatitis B or a combined vaccine against hepatitis A and B.

Alanine Transaminase↗

Prevention of hepatitis C virus infection.

In spite of advances made in our understanding of the biology of the hepatitis C virus (HCV), the epidemiology and natural history of HCV infection, and the treatment of chronic hepatitis C, the development and worldwide implementation of a comprehensive prevention and control strategy remains necessary. A World Health Organization informal consultation with the Viral Hepatitis Prevention Board was convened and met in Geneva, Switzerland, 13-14 May 2002, to review epidemiological and public health aspects of HCV infection, and the various prevention and control strategies that are currently in place. Based on the presentations and discussions, a number of specific recommendations were made, which should be considered in conjunction with previously published recommendations.

Antiviral Agents↗

The seroepidemiology of herpes simplex virus type 1 and 2 in Europe.

OBJECTIVES: To describe the seroepidemiology of herpes simplex virus (HSV) types 1 and 2 in the general populations of eight European countries to better understand recent reported changes in disease epidemiology. METHODS: Belgium, Bulgaria, Czech Republic, England and Wales, Finland, Germany, Netherlands, and Slovenia conducted national cross sectional serological surveys for HSV-1 and HSV-2 between 1989 and 2000. Survey sizes ranged from 3000 to 7166 sera. External quality control was ensured through reference panel testing. RESULTS: Large intercountry and intracountry differences in HSV-1 and HSV-2 seroprevalence were observed. Age standardised HSV-1 seroprevalence ranged from 52% in Finland, to 57% in the Netherlands, 67% in Belgium, 81% in Czech Republic, and 84% in Bulgaria. Age standardised (>12 years) HSV-2 seroprevalence ranged from 24% in Bulgaria, to 14% in Germany, 13% in Finland, 11% in Belgium, 9% in Netherlands, 6% in Czech Republic, and 4% in England and Wales. In all countries, probability of seropositivity for both infections increased with age. A large proportion of teenagers and young adults remain HSV-1 susceptible particularly in northern Europe. Women were significantly more likely to be HSV-2 seropositive in six of seven (p<0.05) countries and HSV-1 seropositive in four of seven (p<0.05) countries, particularly in northern Europe. No significant evidence of a protective role of HSV-1 for HSV-2 infection was found adjusting for age and sex (p<0.05). CONCLUSIONS: There is large variation in the seroepidemiology of HSV-1 and HSV-2 across Europe. The observation that a significant proportion of adolescents are now HSV-1 susceptible may have implications for transmission and clinical presentation of HSV-1 and HSV-2.

Adolescent↗

A comparison of the stage-specific efficacy of chloroquine, artemether and dioncophylline B against the rodent malaria parasite Plasmodium chabaudi chabaudi in vivo.

Chloroquine, artemether and dioncophylline B efficacy against Plasmodium chabaudi was compared. One intraperitoneal injection (10 mg/kg body weight) was given daily over 3 consecutive days to OF1 mice when they were predominantly bearing ring, trophozoite and schizont forms. The parasitaemia was monitored every 2 h during two schizogonic cycles and daily thereafter until parasites were cleared. Chloroquine was more efficient at the trophozoite stage, while artemether was effective against all erythrocytic stages, with a marked efficacy against the trophozoite stage. Chloroquine-treated and artemether-treated parasites displayed a pigment-clumping morphology and lowered the parasitaemia faster than dioncophylline B. Dioncophylline B was effective at trophozoite and schizont stages, but completely ineffective at the ring stage. These results demonstrate that a better timing of drug administration increases the efficacy of common and new antimalarial drugs and provides a model for antimalarial-action monitoring. Drug-induced changes in infected erythrocyte morphology are presented.

Animals↗

A randomised controlled trial with a diphtheria-tetanus-acellular pertussis (dTpa) vaccine in adults.

The aim of this assessor-blinded trial was to compare the immunogenicity and reactogenicity of a candidate diphtheria, tetanus toxoids and acellular pertussis vaccine with reduced antigen content for diphtheria and pertussis (dTpa) with a licensed reduced adult-type diphtheria-tetanus vaccine Td (reduced diphtheria content) and with an experimental candidate monovalent acellular pertussis vaccine with reduced antigen content (pa). The dTpa and pa vaccines had identical pertussis antigen content. A total of 299 healthy adults (> or =18 years, mean age: 30.1 years+/-10.7) were randomised into 3 groups to receive a single dose of one of the study vaccines. In all groups, clinically significant reactions (severe) were infrequent (0-6%) and no serious adverse events were reported during the study. The incidence of local and systemic reactions following the administration of dTpa was comparable to the Td vaccine group. Of the total study group, prior to vaccination 52. 3 and 93.2% of the subjects had anti-diphtheria and anti-tetanus antibody levels > or = 0.1 IU/ml, respectively; and 73.1, 98.2 and 74.5% of the subjects were seropositive for pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) antibodies, respectively. One month after vaccination, a similar percentage of subjects in the dTpa and Td groups had anti-diphtheria (88.4% vs 90. 1%) and anti-tetanus (100% vs 98.9%) antibody levels > or =0.1 IU/ml. Similar anti-FHA (100%) and anti-PRN (98.9%) vaccine response rates were seen in the dTpa and pa groups, while the anti-PT vaccine response rates were 96.8 and 100.0%, respectively. The dTpa vaccine is as well tolerated and immunogenic as the licensed Td vaccine, and additionally, can also boost antibodies against pertussis.

Adhesins, Bacterial↗

[Obstructive sleep apnea syndrome in infants and children].

Obstructive sleep apnea syndrome (OSAS) is characterized by prolonged, generally partial, upper airway obstruction associated with hypoxemia and/or hypercapnia. Main etiological factors include hypertrophy of the tonsils and adenoids, craniofacial abnormalities with reduction in the upper airway caliber, abnormality of neural upper airway control, or a combination of these factors. Symptoms depend on age, but they always include snoring and breathing difficulties during sleep. Diagnosis of OSAS must be established early in order to prevent complications. It is suspected on history, physical examination and investigative confrontation such as nasofibroscopy and imaging. Polysomnography is the gold standard for diagnosis, scoring of the obstruction and distinction between primary snoring and obstructive breathing. Adenotonsillectomy is an effective therapy. For selected patients, craniofacial surgery may be helpful. Some children require continuous positive airway pressure or the nasopharyngeal tube. Tracheotomy is rarely indicated.

Adult↗

Vismione H and structurally related anthranoid compounds of natural and synthetic origin as promising drugs against the human malaria parasite Plasmodium falciparum: structure-activity relationships.

Natural and synthetic anthranoid compounds were subjected to an evaluation against asexual erythrocytic stages of the human malaria parasite Plasmodium falciparum in vitro. Stimulated by the good activities of Vismia guineënsis extracts, a more detailed investigation of the active principles revealed the pre-nylated preanthraquinone vismione H (1) to be a potent antimalarial [50% growth-inhibitory concentration (IC50) 0.088 microg/ml]. On the basis of this finding a series of chemically related phlegmacins (2-5), flavomannins (6-8), and rufoolivacins (9-11) isolated from several species of Cortinarius, a genus of higher fungi, and 5 synthetic vismione-like anthranoids (12-16) were evaluated as well. Although these compounds displayed weaker antiplasmodial effects than did vismione H (1) itself, considerable levels of activity were obtained with phlegmacin B1 (2), flavomannin-6,6'-di-O-methyl ether A1 (6), trans-4-hydroxy-flavomannin-6,6'-di-O-methyl ether A (8), and rufoolivacin B (10). Initial preconditions for activity within the vismiones and related anthranoids were established.

Agaricales↗

Differential sensitivity of erythrocytic stages of the rodent malaria parasite Plasmodium chabaudi chabaudi to dioncophylline B, a highly active naphthylisoquinoline alkaloid.

Four-week-old OF1 mice, infected with synchronized Plasmodium chabaudi chabaudi blood forms, were intraperitoneally injected with the naphthylisoquinoline alkaloid dioncophylline B (10 mg kg(-1) day(-1)) at three consecutive days. The respective groups were treated when rings, trophozoites, and schizonts were predominant. Microscopical observations of thin blood smears were made every two hours after the start of the experiment. A clear dependency of the effectiveness of dioncophylline B treatments on the timing of drug administration was demonstrated. Based upon the evolution of total parasitaemia and the survival rates, it was concluded that ring stages are insensitive to dioncophylline B, while the drug is highly effective when given at the trophozoite stage and partially effective when given at the schizont stage. Dioncophylline B seems to act by inhibiting the haemozoin degradation, as indicated by pigment clumping, and by impairing the segmentation of schizonts.

Animals↗

[A scale of perioperative satisfaction for anesthesia. I--Construction and validation].

OBJECTIVE: To develop and to validate a scale assessing perioperative patient's satisfaction with anaesthesia (Evan). STUDY DESIGN: Descriptive and evaluative study. PATIENTS: The study included 742 adults undergoing a surgical or a diagnostic procedure under general anaesthesia. Emergency, ambulatory and obstetrical cases were excluded. METHODS: A multidisciplinary working party produced 85 questions focusing on various pertinent areas describing satisfaction. After a validation, 25 out of them were selected for the questionnaire. The latter was completed within the 24 hours following anaesthesia by 742 inpatients. RESULTS: Item analysis showed a homogeneous distribution of the answers to each item. Main component analysis allowed to explain 53% of total variance. Six dimensions were isolated by the exploratory analysis: anxiety, embarrassment, fear, pain-discomfort, information and physical needs. Scoring method followed a simple additive model: for each dimension, the scale scored 0-100. The global score represented the sum of the six dimensions also scored 0-100. Acceptability of Evan questionnaire was satisfactory, with a spontaneous non response rate of less than 1% and a completion duration at 11 +/- 8 min. CONCLUSION: A self-completed questionnaire on patient's satisfaction with anaesthetic period was validated, allowing a global and multidimensional assessment of patient's satisfaction.

Adult↗

[A scale of perioperative satisfaction for anesthesia. II--Preliminary results].

PURPOSE: To assess the patient's experience of anaesthesia in the early postoperative period, with a self-completed questionnaire (Evan). STUDY DESIGN: Descriptive and evaluative study. PATIENTS: The study included 742 adults undergoing an elective surgical or non surgical procedure under anaesthesia. METHODS: An Evan questionnaire with 25 questions was completed 24 hours after anaesthesia by the patient. The questionnaire explored six areas, each one being marked out from 0 to 100, as the visual analogue scale. The marks were compared with consideration of age, gender, ASA physical class, type of anaesthesia, anaesthesia duration and type of surgery. RESULTS: The mean global mark was 76 +/- 9 (min-max: 34-99). Marks were lower in the youngest patients, in females, in ASA 1 patients, in longest surgical procedures, especially with regard to areas belonging to "apprehension", "pain-discomfort" and "physical needs". The lowest mark was given for the "information" provided during the pre-anaesthetic evaluation. Differences in marks occurred also between surgical specialities. CONCLUSION: The Evan questionnaire is a valuable tool for assessing the patient's opinion on the perioperative period. Further studies are required to extend its use to other fields, as ambulatory surgery.

Adult↗

[The use of curare-like agents in resuscitation].

OBJECTIVE: To analyse current data on use of neuromuscular blocking agents (NBA) in the intensive therapy unit (ITU) patients and to propose practice guidelines. DATA SOURCES: We did a Medline search of French and English language articles on NBA administration in ITU patients from 1960 to 1998. Data were also selected from our own collection of articles and books. STUDY SELECTION: Original articles, clinical cases, letters to the editor and review articles were considered. DATA EXTRACTION: Data on pharmacology of NBA in the ITU patient were extracted, as well as data on administration patterns and cost. DATA SYNTHESIS: The indications for myorelaxation in ITU patients include either short term use, as in anaesthesia, or long term administration for facilitation of mechanical ventilation, control of increased intracranial pressure, status epilepticus, tetanus and oxygen demand in case of muscular hyperactivity, diagnostic and therapeutic procedures facilitation. A beneficial effect of NBA on the prognosis of the disease for which these agents have been used is not yet proven. Suxamethonium, because for its short onset time and duration of action, is the agent of choice for endotracheal intubation if myorelaxation is required. Among the benzylisoquinolines, atracurium and besilate of cisatracurium are convenient agents in ITU patients, whereas mivacurium is of no special interest. Among the aminosteroids, pancuronium and vecuronium are the most often used agents in the ITU. Rocuronium has not yet been extensively assessed. Myorelaxants carry risks for morbidity and mortality. The difficulty to assess the neurological status and the level of sedation is a recognised adverse effect. An accidental disconnection from the circuit and the resulting asphyxia is nowadays recognised without delay by the ventilator. NBAs increase the rate of bronchopulmonary infections. Cardiovascular complications include extreme bradycardia or sinus arrest following vecuronium administration, and cardiac arrest after suxamethonium injection mainly in burned or traumatised patients. Conversely to anaesthesia, NBAs do not carry a significant risk for anaphylactic or anaphylactoid complications in the ITU. Tachyphylaxis occurs mainly in burns and other pathologies modifying acetylcholine receptors. Neuromuscular complications include myopathy from steroids, postparalytic syndrome, deconditioning syndrome and intensive care polyneuropathy. Prolonged curarisation after discontinuation of NBA administration has a multifactorial origin and must be differentiated from neuromuscular complications. For prolonged neuromuscular blockade, pancuronium, vecuronium and atracurium are the agents of choice. The association with an adequate sedation is essential. Assessment of depth of neuromuscular blockade is not based on clinical symptoms but on train-of-four (TOF) twitch monitoring. A convenient basic relaxation is usually obtained with the suppression of the two last responses to TOF. CONCLUSION: The use of NBA in ITU patient should result from a rational decision making procedure, the blockade titrated with a TOF monitor and maintained as superficially and shortly as possible.

Anesthesia↗

Korundamine A, a novel HIV-inhibitory and antimalarial "hybrid" naphthylisoquinoline alkaloid heterodimer from Ancistrocladus korupensis.

A unique heterodimeric naphthylisoquinoline alkaloid, korundamine A (2), comprised of two different monomeric biaryl halves, has been isolated from the Cameroonian tropical liana Ancistrocladus korupensis. Korundamine A is the first "hybrid" dimer found in the Ancistrocladaceae; in vitro, it demonstrated anticytopathic activity against HIV-1 and antimalarial activity against Plasmodium falciparum.

Animals↗

Antimalarial and cytotoxic potential of four quassinoids from Hannoa chlorantha and Hannoa klaineana, and their structure-activity relationships.

Hannoa chlorantha and Hannoa klaineana (Simaroubaceae) are used in traditional medicine of Central African countries against fevers and malaria. Four stem bark extracts from H. klaineana and four quassinoids from H. chlorantha were examined in vitro against Plasmodium falciparum NF 54. The extracts displayed good activities, while the quassinoids were highly active, with IC50 values well below 1 microgram ml-1, those of chaparrinone and 15-desacetylundulatone being much lower than 0.1 microgram ml-1 (0.037 and 0.047 microgram ml-1, respectively). Chaparrinone is five times more active than 14-hydroxychaparrinone against P. falciparum, indicating that the hydroxyl function at C-14 is unfavourable for antiplasmodial activity. As 14-hydroxychaparrinone has a seven-times higher cytotoxic activity against P-388 cells than chaparrinone, the latter compound has the better antiplasmodial therapeutic index. All four quassinoids were evaluated in vivo in a standard 4-day test as well. 15-Desacetylundulatone was proven to be the most active compound, almost totally suppressing the parasitaemias of OF1 mice for at least 7 days, while both chaparrinone and 14-hydroxychaparrinone were active for at least 4 days. Quassinoids have ED50 values much lower than 50 mg kg-1 body weight day-1 and none of them caused obvious side effects. The keto function at C-2 in 15-desacetylundulatone is apparently of crucial importance for its high activity. 6-alpha-Tigloyloxyglaucarubol was not active at all. Chaparrinone is considered the most interesting of the investigated quassinoids and its in-vivo antimalarial potential will be examined further.

Animals↗

[The effects of midazolam on oxygen consumption and the level of vigilance. The possibility of the sedative effect of the plexiglas dome (canopy) of the Deltatrac indirect calorimetry device].

OBJECTIVE: To assess the effects of midazolam on oxygen consumption (VO2) and the level of vigilance. To search for a possible "sedative effect" of the canopy of the Deltatrac (Datex) when a placebo is administered instead of midazolam. STUDY DESIGN: Prospective, comparative, randomized, double-blinded, cross-over study. PATIENTS: Eight healthy volunteers of ASA physical class 1, not under stress, fasting and at rest. METHODS: The volunteers were administered at T0 either midazolam (0.07 mg.kg-1, IM), or a placebo at a one week interval in an order at random. The VO2 was measured with a Deltatrac. Circulatory status was monitored with non invasive methods and the level of vigilance assessed using the Ramsay scale. Statistical analysis was obtained with Anova for repeated measurements with two within factors (drug and time). RESULTS: VO2 decreased similarly and significantly between T0 and T45 min (P < 0.05). The decrease continued only after midazolam until T60 min. However the variation of VO2 between the midazolam and placebo group was not significant. The haemodynamic variables remained unchanged. Midazolam had a stronger sedative effect at T120 min.

Adult↗