Mutagenicity of nitro- and amino-substituted carbazoles in Salmonella typhimurium. III. Methylated derivatives of 9H-carbazole

The mutagenic potency of nine methylnitrocarbazoles, four methylaminocarbazoles and the methylcarbazole parent compounds was evaluated in Salmonella typhimurium TA98 and TA100, in the absence and presence of S9 isolated from Aroclor-induced rat liver. Nitro derivatives were additionally tested in TA98NR and TA98/1,8DNP6, and mutagenicity of nitrocarbazoles bearing methyl groups in positions 1 and 4 was also determined in TA1537 and TA1977, with and without S9. The addition of methyl groups on non-mutagenic carbazole can induce a mutagenic response where the intensity and nature of the effect depends on the position of the substitution: base-pair substitutions were only observed for N-methylated carbazoles, whereas 1,4-dimethylated compounds exhibited frameshift mutagenicity. All these activities depended on the presence of S9. From its dependence on classical nitroreductases, direct mutagenicity of methylnitro derivatives should be attributed to bacterial reduction of nitro groups. The influence of the methyl groups (and other additional substituents) on mutagenicity of these derivatives is discussed through their effects on life-time and reactivity of the intermediates (i.e., hydroxylamines and nitrenium ions), taking into account the nature, the position and the number of substituted sites Mutagenic activity of methylnitrocarbazoles was also tentatively correlated with various molecular descriptors. Among them hydrophobicity was found to be strongly correlated with the mutagenicity of the 1,4diMe3NC isomers. On the other hand, mutagenic potency of the nitrated and aminated methylcarbazoles varied independently of parameters linked to their oxidoreduction properties (i.e., reduction and oxidation potentials, LUMO and HOMO energies).

Pre-hospital and hospital time delays in thrombolytic treatment in patients with suspected acute myocardial infarction. Analysis of data from the EMIP study. European Myocardial Infarction Project

OBJECTIVES

To compare the components of the time delay involved in pre-hospital and hospital thrombolytic therapy in patients presenting with suspected acute myocardial infarction.

MATERIAL AND METHODS

From October 1988 to January 1992 a total of 198 mobile emergency units in 15 European countries and Canada randomized 5469 patients to receive either pre-hospital thrombolytic treatment, followed by placebo in hospital (pre-hospital group), or pre-hospital (hospital group) in the European Myocardial Infarction Project trial. We performed a post hoc analysis of these data to correlate components of the interval between symptom onset and treatment with baseline patient characteristics.

RESULTS

The delay between onset of symptoms and calling for an ambulance was significantly longer for female patients (P = 0.0001), older patients (> 65 years old; P = 0.0001), those who had experienced pain within the previous 24 h (P = 0.0001), and those with pulmonary oedema (P = 0.04). This delay was significantly shorter in patients with previous myocardial infarction (P = 0.02), those with ventricular fibrillation (P = 0.0001), and those in shock (P = 0.0001). The delay between the two injections was significantly longer for older patients (> 65 years old; P = 0.02), those with previous myocardial infarction (P = 0.03), and those in shock (P = 0.003).

CONCLUSIONS

Action undertaken to reduce delays between symptom onset and treatment should focus on modifiable factors such as patients who are likely to be late callers i.e. women and those over 65 years of age.

Type III-IV laryngotracheoesophageal cleft: report of a successfully treated case

This report presents a case of Stage III laryngotracheoesophageal cleft (LTEC). It is, to our knowledge, the fourth case in which the patient is still alive twenty months after surgery. We herein describe an initial symptomatology dominated by a bubbling hypersalivation, our surgical technique using a pleural shred of interposition and an endoscopic check during the operation and, finally, the clinical development dominated by a food intake refusal which was progressively improved through psychiatric help.

Perfusion-MVO2 mismatch during inotropic stress in CAD patients with normal contractile function

With the use of[11C]acetate, positron emission tomography (PET) permits exploration of myocardial blood flow (MBF) and oxidative metabolism (MVo2) coupling. PET imaging was performed at rest and under dobutamine infusion in 8 normal subjects and 10 coronary artery disease (CAD) patients with significant single-vessel left anterior descending (LAD) stenosis (> 70%) and normal regional left contractile function at rest. Resting MBF and MVo2 were similar in remote and LAD regions of normal subjects and patients. During dobutamine infusion, MBF and myocardial flow reserve were lower in LAD regions of patients compared with remote regions (MBF: 1.49 +/- 0.42 and 2.06 +/- 0.57 ml.g-1.min-1, P < 0.01; reserve: 1.73 +/- 0.59 and 2.14 +/- 0.47, P < 0.01, respectively), whereas MVo2 expressed as kmono (an index of MVo2) and metabolic reserve were similar (kmono: 0.106 +/- 0.021 vs. 0.107 +/- 0.017 min-1; reserve: 1.88 +/- 0.32 vs. 1.98 +/- 0.37, respectively). This is the first human study showing that, in normal contractile regions at rest but perfused by stenosed artery, a disparate rise in MVo2 relative to the rise in myocardial perfusion occurs during increased cardiac work induced by dobutamine. This flow-metabolism uncoupling probably reflects an increase in O2 extraction.

Common cis-acting elements critical for the expression of several genes of Toxoplasma gondii

Transient transformation of Toxoplasma using the CAT (chloramphenicol acetyl transferase) reporter gene has been used to map promoter elements of four genes encoding dense granule proteins (GRA1, GRA2, GRA5 and GRA6). Intense CAT activities (GRA1 > GRA5 > GRA2 > GRA6) are detected for constructs containing 379bp, 276bp, 209bp and 265bp upstream of the transcription start site of the GRA1, GRA2, GRA5 and GRA6 genes, respectively. Deletion analysis shows that optimal promoter activity of each gene is contained in the proximal region of the transcription start site: -129 to -47 for GRA1, -87 to -37 for GRA2, -156 to -30 for GRA5 and -146 to -27 for GRA6. Quantitative CAT assay and mutation analysis show that repeated motifs (A/TGAGACG) found in either orientation with respect to transcription are critical elements of these defined promoter regions. We have found such sequence elements in the upstream region of other Toxoplasma genes such as Tub1 and within the stretch of 27bp repeats of the SAG1 promoter.

Strategies for involving physicians in continuous quality improvement

To realize significant and sustained improvement in quality and in overall performance, hospitals must have the support and participation of the medical staff. Although it sometimes is difficult to recruit busy physicians to join the effort, they will become champions if their experience is productive and results in improved patient care. This article outlines a number of straightforward approaches that will help healthcare quality professionals obtain physician involvement in the improvement effort.

Direct intraoperative sclerotherapy of an aneurysmal bone cyst of the sphenoid

A young boy presented with a symptomatic aneurysmal bone cyst of the left great wing of the sphenoid bone. Arterial embolization had failed to produce thrombosis, and the lesion could not be resected surgically. Direct intraoperative sclerotherapy resulted in immediate thrombosis of 80% of the volume of the vascular malformation with no progression of symptoms. Two years later, the symptoms had completely resolved, and CT scans showed total ossification of the lesion.

Lidocaine plasma concentrations in pediatric patients after providing airway topical anesthesia from a calibrated device

The aim of this prospective study was to evaluate plasma lidocaine concentrations in infants and children after laryngeal spray using a calibrated device. Twenty-one patients aged 3 to 24 mo requiring laryngoscopy or bronchoscopy were included in the study. Anesthesia was induced via a mask with halothane up to 2% in 100% O2. Lidocaine was administered using a 5% lidocaine spray. For patients weighing less than 10 kg, one spray (8 mg of lidocaine) was administered. For those weighing from 10 to 20 kg, two sprays (16 mg) were given. The dose of lidocaine administered ranged between 0.9 and 2.6 mg/kg. Maximum plasma lidocaine concentration (Cmax) was 1.05 +/- 0.55 micrograms/mL (mean +/- SD; range 0.24-2.29 micrograms/mL). With this procedure, we demonstrated the safety of administering lidocaine to children by laryngeal spraying using a 5% sprayer.

No season-of-birth effect in schizophrenic patients from a tropical island in the Southern Hemisphere

The distribution of birth rates was examined in 668 schizophrenic patients born in Réunion, a tropical French island in the Southern Hemisphere, and compared with that in the general local population. We failed to observe a significant season-of-birth effect, either in the total sample of schizophrenic patients or in subgroups categorized by gender, age, or family history of schizophrenia. Seasonal factors do not appear to affect the yearly distribution of births among schizophrenic patients on Réunion Island. It is nevertheless possible that environmental factors which are seasonal in countries with more contrasting climates have a continuous effect, throughout the whole year, in subtropical areas. Conversely, these findings provide some evidence against the hypothesis that there is an age-incidence artifact in seasonal studies from countries in the Northern Hemisphere.

Ventricular fibrillation following administration of thrombolytic treatment. The EMIP experience. European Myocardial Infarction Project

Reperfusion-induced ventricular fibrillation has been demonstrated in animal models of myocardial ischaemia, but no evidence exists for this in humans. The European Myocardial Infarction Project compared the efficacy and safety of pre-hospital thrombolytic therapy with that of hospital therapy. The objective of this study was to investigate the occurrence of reperfusion-induced ventricular fibrillation in acute myocardial infarction patients following thrombolytic therapy. In a double-blind multicentre trial, eligible patients were randomized to receive anistreplase at home followed by placebo in the hospital (A/P group), or placebo followed by anistreplase (P/A group). The occurrence of ventricular fibrillation, and other adverse events were recorded on specific study forms and could be attributed to defined time intervals. The incidence of ventricular fibrillation in the A/P group was significantly higher following the pre-hospital injection than in the P/A group (2.5% vs 1.6%; P = 0.021); the situation was reversed following the hospital injection (3.6% vs 5.3%; P = 0.002). No relationship was found between this excess of ventricular fibrillation and the patients' condition, with the exception of the site of the infarct. These results suggest the existence of reperfusion-induced ventricular fibrillation in patients developing myocardial infarction who receive thrombolytic treatment.

Epidemiological survey of childhood burn injuries in France

Among domestic injuries in children, skin burns deserve special attention because they can lead to severe residual lesions. Their frequency has been reported to range from 3 to 8 per cent of all childhood injuries, but few epidemiological data have been collected in France. This study was undertaken to improve our knowledge of this public-health problem. A 20-item epidemiological questionnaire developed by the SFETB was used to collect prospective data on childhood burn injuries managed over a 12-month period in 14 burn centres and 18 paediatric surgery units in France. Of the 937 patients included in the study, 606 were contributed by burn centres and 331 by paediatric surgery units. Descriptive analysis and tests for correlations between several parameters showed that the typical burn-injury patient was a boy (61.6 per cent) with a mean age of 47 months, who suffered a scald burn (64.1 per cent) in the kitchen (56.2 per cent). The bathroom (13.6 per cent) was found to be an especially dangerous room because of the presence of hot water taps (shower, bathtub) and the high risk of an immersion injury. Burns due to ignition of volatile substances (16.95 per cent) were less common, but caused seven of the 11 deaths recorded in this survey. Most burn injuries were superficial lesions (59 per cent) covering less than 10 per cent of the body surface (56.2 per cent). However, grafting was required in 35 per cent of patients. Epidemiological surveys provide objective information on hazardous agents and on the settings in which burns are most likely to occur. They are essential for the development of appropriate preventive strategies, which are still receiving insufficient emphasis in the European Economic Community (EEC).

Stable DNA transformation of Toxoplasma gondii using phleomycin selection

Toxoplasma gondii (Tg) is an obligate intracellular protozoan parasite that is an important opportunistic pathogen in humans. To provide additional tools for molecular genetic analysis, we have developed a set of vectors for DNA transformation in Tg based on selection with the antibiotic phleomycin (Ph). These new vectors rely on the flanking sequences from the parasite genes GRA1, GRA2 or SAG1 to drive expression of the Tn5 ble gene encoding resistance to the DNA intercalating drug Ph (PhR). Treatment of extracellular parasites was used to select stable PhR transformants by plaque formation on host cell monolayers. Transfection of linear or circular forms of the pGRA1/ble, pGRA2/ble or pSAG1/ble vectors by electroporation resulted in stable transformation with an efficiency of approx. 10(-4)/micrograms DNA. Stable transformants contained 1-5 copies of ble that were integrated at non-homologous sites in the parasite nuclear genome. Ble provides a new dominant selectable marker for safe, efficient and rapid isolation of stable DNA transformants in Tg.

[French epidemiological survey of burns in children under 5 years of age]

AIMS

To add to epidemiological data concerning serious accidents in the home in France.

PATIENTS AND METHODS

This prospective study, carried out over 12 months, included all children with burns admitted to 14 burn units (BU) and 18 pediatric surgery units (PS) using a questionnaire from the SFETB comprising 20 items.

RESULTS

On population 0 to 60 months, 687 patients were included (434 in BU, 253 in PS). Descriptive analysis and correlation of several parameters identified patterns of burns in childhood and the factors of severity. Victim data: young boys (59.3%), aged < 36 months (mean = 24 months), burned at home, in the kitchen (62.4%) with hot fluids (73%), or bathroom (16.2%) with tap water by immersion. Flames were cause of burns (8.7%) by inflammable products. Lesions were always more severe in surface and risk of mortality was higher. Burns covered a surface equal or less than 10% in 57% of cases.

CONCLUSIONS

The value of the study was to be more aware of the dangers of which children are exposed and to encourage application of preventive measures.

Cellular and humoral immune responses to recombinant antigens in sheep infected with Toxoplasma gondii

Immune responses to recombinant fragments of the Toxoplasma gondii antigens ROP2 and GRA2 were investigated in sheep naturally and experimentally infected with T. gondii oocysts. Specific serum antibodies to C-terminal fragments were detected by ELISA. Cell-mediated responses in peripheral blood mononuclear cells were demonstrated by proliferation and interferon-gamma production following in vitro stimulation with the ROP2 fragment. This data indicates the presence of epitopes for sheep B cells in the recombinant GRA2 fragment and for both B and T cells in the ROP2 fragment.

[DARC/PELCO structure activity relationships of aldosterone agonists and antagonists]

To detect the sites essential for binding affinity, we use the DARC/PELCO topological correlation search method and apply it to 52 17-spirolactone or 17-hydroxymethylcarbonyl steroids, aldosterone agonists or antagonists. The optimal model explains 98% of the total variance with a precision close to experimental. The main favourable contributions come from direct substitutions on rings C and D of the steroidal skeleton, the most unfavourable from those on rings A and B. The secondary structural modifications - modifications of existing substituents or second substitutions on the focus - have a slight deactivating influence, except the simultaneous existence of two contiguous double bonds on the 11 beta chain. Structures predicted to have a high affinity are built up by combining the most favourable structural elements: 9 alpha-F, 11 beta-allenyl, delta 11, 12 and 15 beta-, 16 beta-CH2. Some are predicted to have an affinity 100- to 1000-fold higher than aldosterone.

Characterization of a dense granule antigen of Toxoplasma gondii (GRA6) associated to the network of the parasitophorous vacuole

This work describes the molecular characterization of GRA6, a novel Toxoplasma gondii dense granule antigen of 32 kDa. cDNA clones encoding this protein were isolated using a rat serum directed against an HPLC fraction enriched in the protein GRA5. Cross-reactivity between GRA5 and GRA6 was demonstrated by production of sera against the recombinant GRA5 protein. A serum against a recombinant fragment of GRA6 which does not react with GRA5 allowed the localization of this antigen at the subcellular level. GRA6 is detected in the dense granules of tachyzoites, and in the parasitophorous vacuole, closely associated to the network. The gene encoding GRA6 and its flanking regions were completely sequenced from cDNA and genomic inserts. Primer extension experiments demonstrated that the cap site of the GRA6 gene was located 37 bp upstream of the 5' end of the longest cDNA insert (1600 bp). The GRA6 gene potentially encodes a 230-amino-acid polypeptide, does not contain any introns and seems to be present as a single copy in the genome of T. gondii. The deduced polypeptide contains two hydrophobic regions with the characteristics of transmembrane domains. The N-terminal domain does not fit the classical feature of a signal peptide. The central hydrophobic domain is flanked by two hydrophilic domains which contain four blocks of amino acids homologous to the GRA5 protein. The C-terminal hydrophilic region comprises 24% of glycine residues, which may indicate a structural role for GRA6 in the network.

Case management with homeless women: a descriptive study

This article presents the results of a three-year survey of the activities of two case managers following 25 homeless women with substance abuse problems. The case managers' activity record indicated that a great deal of the case managers' energy was devoted to providing direct, concrete services. More than half the clients received four weekly contacts, for an average total of two hours/client/week. Furthermore, direct support accounted for 42.2% of all contacts reported by the case managers, suggesting that, although case managers fill many different functions, establishing and maintaining a significant relationship with the participants constituted a major part of their work. The study confirms that a high staff-to-client ratio is required to respond to the multiple needs of this population.

Reducing the incidence of sharps injuries

Sharps injuries are the primary route through which health care workers acquire blood-borne diseases occupationally (Lynch et al, 1992). In order to reduce the incidence of such injuries effectively within a hospital, it is vital to first ascertain the frequency and types of injuries and then implement a risk-reduction programme based on the specific problems identified.

"Subjective quality of life": clinical model for assessment of rehabilitation treatment in psychiatry

The aim of this study was to develop a comprehensive model in order to approach the structure of the concept of subjective quality of life. A total of 188 Belgian subjects took part in the present study: 148 psychiatric out-patients and 40 normal controls. The principal component analysis used as a statistical method revealed three significant factors for the model: a first one called "hedonist factor" with a high level of interdependencies and subjective satisfaction, a second one called "achievement factor" and a third one called "conformity factor". Contrary to the hypothesis of the Social Indicators movement, it appeared that items related to the objective satisfaction of needs were not related to items of the subjective quality of life, as defined by the international literature.

Tantalum-Dacron coknit stent for endovascular treatment of aortic aneurysms: a preliminary experimental study

PURPOSE

The purpose of this study was to evaluate the efficiency of intraluminal tantalum-Dacron coknit stents for the treatment of artificial aortic aneurysms in minipigs.

METHODS

Replacement of the infrarenal abdominal aorta with Dacron artificial aneurysm graft was performed in eight minipigs. After 2 weeks, balloon-expandable coknit stents were inserted through the femoral artery to the site of the artificial aneurysm in seven minipigs. One animal was kept as a control. Coknit stent/artificial aneurysm complexes were explanted at various intervals from 24 hours to 12 weeks and underwent gross examination, followed by scanning electron and light microscopy studies.

RESULTS

Aortography performed at the time of stent placement displayed immediate exclusion of the aneurysm in every case. In follow-up studies, all coknit stents remained patent until the time of explant. Scanning electron microscopy studies revealed apparent endothelialization of the entire coknit stent lumen at and after 6 weeks.

CONCLUSION

Tantalum-Dacron coknit stents are efficient in the treatment of artificially created aneurysms in minipigs and facilitate the creation of an endothelialized new vascular wall. Clinical application of this coknit stent can be considered but necessitates retaining the same stent structure in diameters greater than 20 mm and the development of a suitable delivery system.

Safe food manufacturing

Food safety is a growing preoccupation of the health authorities and the major food companies in any European country. All the aspects of food manufacturing, from the raw materials until the product is consumed have to insure they are innoxious to human health, eliminate any harmful effects related either to food handling or consumption in domestic or common eating places, as well as protect, as much as possible, our environment. Thus, the food manufacturer has to examine step-by-step the security of the agro-cultures, their composition, but also the possible residues of pollutants and contaminants, or chemicals used to protect them against various pests and determine the possible loss or retention of these substances during technological processes. Animal raw materials should not contain veterinary drug residues or an abnormal amount of some components that result from inadequate feeding. Care should be taken to ensure the security of foods manufactured by biotechnology processes. The organisms and the whole processes used in food biotechnologies should eliminate any impurities. Any minor food ingredients, such as food additives, are under a permanent revision from the point of view of their safety. The industry reacts immediately if any justification requires that a particular food additive should not be used. In other words all the raw materials must conform to their specifications. Technological processes must create a food with an adequate microbiological quality, e.g. free of pathogens and their toxic metabolites. Any danger of microbiological contamination or accidental pollution, such as mechanical particles, chemical substances, etc. should be eliminated. The particular role of food packaging is crucial, since this is a barrier to protect the food against further parasites or microbial contamination and preserve the food from alterations due to enzymatic reactions that require particular oxygen and water activity conditions. The packaging should also protect against possible criminal damage. In addition, the material of packaging should not allow micro-migration to the food. It should be inert against its food content. Another aspect of food packaging that has to be taken into account is its recovery and recyclability. Finally, the food manufacturer has to ensure that the nutritional value of the product does not diminish through its shelf-life. The consumer should be advised about the effects of culinary practices since some of them, such as deep frying or grilling under certain circumstances, may create undesirable substances potentially harmful to human health. The food manufacturing in the context of the environment protection requires a separate issue.(ABSTRACT TRUNCATED AT 400 WORDS)