[Multidisciplinary treatment of neurologic pain and indications for antalgic surgery]

We present our multidisciplinary approach systematically adopted for patients with resistant pain. All the anatomic, pathophysiological, clinical, radiographical, electrophysiological and psychological aspects of pain should be considered before deciding on treatment indication. These principles are illustrated by a description of different available medical and surgical techniques for the treatment of paraplegic pain. We emphasize the importance of pain centers in caring for these patients. All possibilities for antalgic treatment can be considered in such centers, providing a better approach to all aspects of pain.

The practice of structure activity relationships (SAR) in toxicology

Both qualitative and quantitative modeling methods relating chemical structure to biological activity, called structure-activity relationship analyses or SAR, are applied to the prediction and characterization of chemical toxicity. This minireview will discuss some generic issues and modeling approaches that are tailored to problems in toxicology. Different approaches to, and some facets and limitations of the practice and science of, SAR as they pertain to current toxicology analyses, and the basic elements of SAR and SAR-model development and prediction systems are discussed. Other topics include application of 3-D SAR to understanding of the propensity of chemicals to cause endocrine disruption, and the use of models to analyze biological activity of metal ions in toxicology. An example of integration of knowledge pertaining to mechanisms into an expert system for prediction of skin sensitization to chemicals is also discussed. This minireview will consider the utility of modeling approaches as one component for better integration of physicochemical and biological properties into risk assessment, and also consider the potential for both environmental and human health effects of chemicals and their interactions.

Epidemiology of recurrences or reinfections of Clostridium difficile-associated diarrhea

Approximately 15 to 35% of patients with a first episode of Clostridium difficile-associated diarrhea relapse within 2 months. Between 1994 and 1997, strains from 93 hospitalized patients with C. difficile recurrences were fingerprinted by using both serotyping and PCR-ribotyping. The results showed that 48.4% of clinical recurrences were, in fact, reinfections with a different strain of C. difficile. Rates of clinical recurrences could therefore be reduced by implementing strict isolation precautions.

Epidemiology of recurrences or reinfections of Clostridium difficile-associated diarrhea

Approximately 15 to 35% of patients with a first episode of Clostridium difficile-associated diarrhea relapse within 2 months. Between 1994 and 1997, strains from 93 hospitalized patients with C. difficile recurrences were fingerprinted by using both serotyping and PCR-ribotyping. The results showed that 48.4% of clinical recurrences were, in fact, reinfections with a different strain of C. difficile. Rates of clinical recurrences could therefore be reduced by implementing strict isolation precautions.

Parietal and cingulate processes in central pain. A combined positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) study of an unusual case

Parietal, insular and anterior cingulate cortices are involved in the processing of noxious inputs and genesis of pain sensation. Parietal lesions may generate central pain by mechanisms generally assumed to involve the 'medial' pain system (i.e. medial thalamic nuclei and anterior cingulate cortex (ACC)). We report here PET and fMRI data in a patient who developed central pain and allodynia in her left side after a bifocal infarct involving both the right parietal cortex (SI and SII) and the right ACC (Brodmann areas 24 and 32), thus questioning the schematic representation of cortical pain processing. No rCBF increase was found in any part of the residual cingulate cortices, neither in the basal state (which included spontaneous pain and extended hypoperfusion around the infarct), nor during left allodynic pain. Thus, as previously observed in patients with lateral medullary infarct, neither spontaneous pain nor allodynia reproduce the cingulate activation observed after noxious pain in normal subjects. Conversely, both PET and fMRI data argue in favour of plastic changes in the 'lateral discriminative' pain system. Particularly, allodynia was associated with increased activity anteriorly to the infarct in the right insula/SII cortex. This response is likely to be responsible for the strange and very unpleasant allodynic sensation elicited on the left side by a non-noxious stimulation.

Optical contrast in apertureless microscopy

We report on optical image contrast for a specific apertureless near-field optical microscope. We demonstrate that the main part of the optical image's contrast results from the sample's topography. The coupling mechanism is analyzed, and we show that the microscope can be regarded as an interferometer that sensitively detects near-field components. However, in the basic configuration the reference field of the interferometer is coupled to the topography. Finally, it is demonstrated that, by controlling the phase of the reference field, one can largely decorrelate the optical image from the topography.

[Epidemiology of gastro-esophageal-reflux in general practice. . Predictive factors for health care utilization in the course of a year]

AIM

To assess the epidemiology and course of GORD, treatment demand, and factors predictive of GORD course in a 1-year study in patients with heartburn consulting general practitioners.

METHODS

A total of 984 patients with pyrosis were included by general practitioners. After the initial visit, they had follow up at 3, 6 and 12 months by phone contact.

RESULTS

Most patients (87%) had been suffering from heartburn for 4+/-1.5 years; upper GI endoscopy had been performed in 63% of patients. Patients evaluated the symptoms of the current episode as mild (6%), moderate (60%), or severe/incapacitating (34%). During the year of follow up, 12% of the patients were free of heartburn; the mean number of consultations with general practitioners and gastroenterologists was 5.1 and 0.5 respectively. At day 90, discomfort due to heartburn was absent in 4% of patients, slight in 51%, moderate in 32%, and severe in 6%. At day 360, predictive factors for discomfort were: discomfort related to heartburn on D90, the length of time the patients had been suffering from GORD, and the main reason for consultation on D1; patients for whom heartburn was not the main reason for consultation on D1 experienced a higher level of discomfort. The predictive factors for the extent of treatment demand over 12 months were: age, discomfort related to heartburn on D90, severity on D1, the frequency of episodes prior to the episode on D1 and the levels of stress and anxiety measured on D1.

CONCLUSIONS

Epidemiologic characteristics of patients with heartburn consulting a general practitioner were different from these of the general population. Treatment demand depends both on severity of heartburn and level of stress and anxiety.

Sebum rheology evaluated by two methods in vivo. Split-face study of the effect of a cosmetic formulation

Modulation of the rheological characteristics of sebum at the surface of the skin might represent a valuable strategy for the treatment of seborrhea. In this field, only a small number of studies have addressed sebum diffusion within the stratum corneum. In an open, split-face study conducted on 20 men, we measured the sebosuppressive effect of Effidrate cream which is based on a glycerol alkyl-ether. Measurements were made in the morning at three-week intervals for a total period of 3 months. Sebum casual levels and sebum excretion rates were measured using a SM810 Sebumeter. Lipid-absorbent Sebutape was also used to collect all the sebum released from infundibular reservoirs over a four-hour period. Clinical assessments were relatively uninformative but the photometric measurements showed that Effidrate cream had a sebosuppressive action. The underlying biological mechanism remains unclear but a hypothesis based on enhanced sebum absorption by the stratum corneum is discussed.

Field enhancement and apertureless near-field optical spectroscopy of single molecules

We report on fluorescence enhancement in near field optical spectroscopy by apertureless microscopy. Our apertureless microscope is designed around a confocal fluorescence microscope associated with an AFM head. First, we show that the confocal microscope alone allows single molecule imaging and single molecule fluorescence analysis. When associated with the AFM head, we demonstrate, for the first time to our knowledge, that single molecule fluorescence is enhanced under the silicon tip. We tentatively attribute this effect to field enhancement under the tip.

Efficacy of protective creams in a modified repeated irritation test. Methodological aspects

The effect of 3 protective creams and petrolatum was tested in a repetitive irritation test. On 15 healthy volunteers, the irritants (sodium lauryl sulfate 10%, sodium hydroxide 0.5%, lactic acid 15%, and toluene undiluted) were applied on the paravertebral skin of the mid-back after 30 min pretreatment with the products tested. The volunteers were treated for 9 days. The irritant cutaneous reactions were quantified by erythema score, transepidermal water loss, and chromametry. The results showed a specific profile of efficacy against the 4 irritants used. For all creams a significant protective effect was obtained against irritation by sodium lauryl sulfate, sodium hydroxide and lactic acid in different degrees. Less efficacy was observed against toluene. Even an amplification of inflammation by pretreatment with 1 product could be demonstrated. The results indicate that a 1-week period of cumulative irritation might be enough to evaluate the efficacy of protective creams against most irritants.

Evaluation of decoquinate to treat experimental cryptosporidiosis in kids

The purpose of this trial was to evaluate the effects of decoquinate at 2.5 mg/kg/day for 21 days to prevent an experimental cryptosporidiosis in kids. Twenty 1-day-old male kids (French Alpin), fed initially goat colostrum heated 1 h at 56 degrees C and fed twice daily with nonmedicated milk replacer, were assigned into 2 groups. Kids of both groups were orally inoculated with 10(6) Cryptosporidium parvum (D0 = inoculation day). Group A kids were kept as nonmedicated controls and group B kids were orally medicated with 2.5 mg/kg/day of decoquinate (Deccox L. Rhône Poulenc Animal Nutrition) for 21 days from D-3 to D17. The studied criteria were body weight gain, oocyst shedding and specific anti-C. parvum immune response. In group A, the inoculation was not followed by mortality; but only by diarrhea and high oocyst shedding. Decoquinate reduced the severity of cryptosporidiosis in group B kids. The treatment prevented episodes of diarrhea and weight gain decrease for the D0-D7 and D0-D14 disease periods but did not allow a better final weight gain. The oocyst shedding was decreased in number and in duration. This parasitic development has induced a specific anti-C. parvum immune response. This drug is well-tolerated by animals and may be recommended in the prevention of ruminant cryptosporidiosis, a disease which has very limited treatment options.

Interference of HIV-1 Nef in the sphingomyelin transduction pathway activated by tumour necrosis factor-alpha in human glial cells

OBJECTIVE

The HIV-1 nef gene product, thought to interact with mediators of cell signalling, is overexpressed during the restricted HIV-1 infection of human astrocytes. This infection can be reactivated following exposure to tumour necrosis factor (TNF)-alpha. We examined the possibility that Nef alters the TNF-alpha-induced cell signalling in astroglioma cells through the sphingomyelin pathway.

METHODS

Sphingomyelinase activation by TNF-alpha was analysed in U251MG glial cells constitutively expressing Nef and compared with U251MG cells stably transfected with the expression vector alone. The consequent effect on the cellular proliferative response and induction of nuclear factor NF-kappa B and AP-1 binding activities were examined.

RESULTS

A marked enhancement in the levels of ceramide, a product of the sphingomyelin hydrolysis, was observed in U251MG-Nef upon stimulation with TNF-alpha. In contrast, ceramide levels in control cells were barely increased under similar conditions. A concomitant reduction of sphingomyelin level occurred in U251MG-Nef cells. In addition, the reduced survival rate of U251MG cells resulting from TNF-alpha activation was prevented in the presence of Nef. Furthermore, electrophoretic mobility shift assays indicated that nef expression inhibits AP-1 activation without altering the induction of NF-kappa B.

CONCLUSION

These results strongly suggest that nef expression in U251MG cells modulates the sphingomyelinase signalling pathway triggered by TNF-alpha, thus leading to important modifications in the activation and proliferation of glial cells. They also provide new insights to explain the widespread reactive astrogliosis observed in AIDS-associated neuropathological disorders.

Perception of risk, choice of maternity site, and socio economic level of twin mothers

The objective of this study was to determine if access to high level health facility (level 3 perinatal center) is related to socio-economic level of the mother and to her perception of risk for a twin birth. A retrospective questionnaire was administrated to the mothers of twins during the first post parum days in each of the 27 maternity sites within a defined geographical district near Paris (Hauts de Seine). The survey instrument was designed to precisely characterize the socioeconomic status of the parents, to measure the perceived risk for the twins expressed by the mother, to measure the relationship between the choice of a maternity site (level 1, 2 or 3) by socioeconomic level, and to measure the fetal and neonatal death rates by socioeconomic status. The opinion of mothers of twins about specific risk for her and for her children is very different by socioeconomic levels, as is the choice of level 3. This is discussed with the rates of fetal and neonatal death rates by socioeconomic level. In the absence of a policy of regionalization of perinatal care, the discriminant factor for access to high level care (level 3 maternity site) is the socioeconomic level.

Undertreatment in a nonselected population of adult patients with asthma

BACKGROUND AND AIM

The question of undertreatment has frequently been raised concerning the management of asthma but, to date, very few studies have been carried out. In those studies that have been performed, the methodology was inadequate because they were conducted on a selected population of patients with asthma or by interviewing doctors. As part of the European Community Respiratory Health Survey, nonselected patients with asthma (22 to 44 years old) in two French cities (Paris and Montpellier), were examined to assess possible undertreatment.

METHODS

Patients with asthma were recruited according to a positive response to questions on asthma in a questionnaire and a positive methacholine challenge. The severity of asthma was assessed by a cumulative score, which has previously been shown to be significantly correlated with the validated clinical score of Aas. Patients were asked to attend the clinic and bring with them any medications that they regularly received. The optimal treatment of asthma was based on the International Consensus Report on the Management of Asthma.

RESULTS

According to the international guidelines, among the patients who required antiinflammatory treatment, 86.4% were undertreated in Paris and 66.7% were undertreated in Montpellier (p < 0.03, chi square test). Moreover, among the patients with severe asthma, 85% and 60%, respectively, were not receiving an antiinflammatory treatment.

CONCLUSION

This study is the first to highlight the magnitude of undertreatment of patients with asthma in a nonselected population.

Comparative effects of haloacetic acids in whole embryo culture

A major class of disinfection by-products in drinking water are the haloacetic acids. Both dichloro- and trichloroacetic acids are teratogenic when administered to rats throughout organogenesis. However, there is little information regarding the developmental toxicity of other haloacetic acids. Therefore, 3-6 somite staged CD-1 mouse embryos were exposed to acetic acid (AA) or mono- (M), di- (D), and tri- (T) substituted fluoro- (F), chloro- (C), or bromo- (B) acetic acids in whole embryo culture in order to evaluate the effects of these agents on development. A 24 hour exposure to the haloacetic acids produced dysmorphogenesis. Effects on neural tube development ranged from prosencephalic hypoplasia to non-closure defects throughout the cranial region. Exposure to the haloacetic acids affected optic development, produced malpositioned and/or hypoplastic pharyngeal arches, and resulted in perturbation of heart development. In order to determine the relative toxicities of these agents, benchmark concentrations were calculated as the lower 95% confidence interval of the concentration that produced a 5% increase in neural tube defects. The benchmark concentrations occurred over a wide range with DFA (5912.6 microM) and MBA (2.7 microM) at the extremes. Using the benchmark concentrations to compare the chemicals gives a ranking of the agents in order of increasing potency as: DFA < TFA < DCA < AA < TBA < or = TCA < DBA < MCA < MBA. TCA and DCA have demonstrated ability to disrupt development in vivo but were among the least potent haloacetic acids in vitro. Because of the potential for widespread exposure to haloacetic acids in drinking water and the incomplete toxicity profile of these chemicals, further work on their developmental effects is warranted.

Maternal-fetal hemorrhage: a reappraisal

PURPOSE

To determine the frequency of maternal-fetal hemorrhage at or above 1 microliter of maternal whole blood.

METHODS

Seventy-three mothers whose red blood cells bore an Rh antigen (Rh D, Rh c, Rh E) that was absent on red blood cells of their newborns were identified and a new cytological method, the Kleihauerimmunogold-silver-staining technique, was applied on the blood of their neonates to detect and quantify maternal red blood cells. Stringent precautions were taken to avoid contaminations of neonatal blood samples by adult red blood cells.

RESULTS

Maternal red blood cells were present in 3 newborns, a frequency of 4% (95% Cl: 1-11%), and the estimated volumes of hemorrhage were 0.8, 1.5, and 101 microliters of maternal whole blood. No obstetric factor was clearly associated in this limited study with the occurrence of maternal-fetal hemorrhage.

CONCLUSIONS

Mother-to-fetus microtransfusion greater than 1 microliter is infrequent at or near delivery, and it may be observed after an uncomplicated pregnancy and vaginal delivery.

Variations in response of four lines of ring-necked pheasants to infection with marble spleen disease virus

This study evaluated the response and susceptibility of four lines of ring-necked pheasants to infection with marble spleen disease (MSD) virus. Fifteen birds of the following lines were used: the standard ring-necked gamebird, the highly inbred jumbo white, the Sichuan, and the first-generation cross of the Sichuan and the standard gamebird. Baseline immune responses were assessed at 6 weeks of age by lymphoblastogenesis assays. All birds were orally challenged at 7 weeks of age with cell -culture-propagated MSD virus. Eight birds of each group were necropsied at 6-7 days post-inoculation (PI), and gross splenic lesions were recorded. Appropriate tissue sections were collected, fixed in 10% buffered formalin, and routinely processed for microscopic evaluation. The remaining birds were bled weekly from week 2 through week 8 Pl. Serum was tested for antibodies to MSD virus using a commercial enzyme-linked immunosorbent assay kit. Results of the lymphoblastogenesis assays and the gross and microscopic lesion incidences indicated that variations did exist between several lines evaluated. The jumbo white pheasant had significantly higher lymphoblastogenesis stimulation index and was more resistant to developing gross and histologic lesions than was the standard ring-necked gamebird.

C2-ceramide primes specifically for the superoxide anion production induced by N-formylmethionylleucyl phenylalanine (fMLP) in human neutrophils

Activated sphingomyelinases release ceramide molecules believed to be involved in intracellular signalling. The present study investigated whether soluble C2-ceramide modulates some of the effects of N-formylmethionylleucyl phenylalanine (fMLP) and other agonists on human neutrophils (or polymorphonuclear leukocytes-PMN); principally superoxide anion (O2-) production. The preincubation of PMN for 15 min with C2-ceramide increased by up to almost 3-fold the amounts of O2- generated in response to 0.1 and 1 microM fMLP. Priming was detected at C2-ceramide concentrations of 2 microM to 4 microM per million PMN. Though less potent than C2-ceramide, C6-ceramide (N-hexanoylsphingosine) could prime for O2- generated in response to 0.1 microM fMLP, with maximal effects obtained at 10-20 microM. In contrast, micromolar concentrations of sphingosine, dihydroceramide, and ceramide-phosphate, failed to exert any potentiating effect on fMLP-induced O2- generation. As expected, TNF-alpha (1000 U/ml), also primed for fMLP-induced O2- production; however, the combination of TNF-alpha and C2-ceramide showed no additive effect. Moreover, S. aureus sphingomyelinase (0.1 U/ml), was unable to reproduce the priming effects of C2-ceramide and TNF-alpha. C2-ceramide at 2 microM did not enhance the production of O2- induced by 100 nM recombinant human interleukin-8 (IL-8), leukotriene B4 (LTB4), platelet-activating factor (PAF) or 20 mM sodium fluoride (NaF). Furthermore, C2-ceramide (2 microM) did not enhance the mobilization of calcium, the release of arachidonic acid or the accumulation of phosphatidylethanol, induced by 100 nM fMLP. This suggests that probably neither phospholipases C, A2 or D (PLC, PLA2, PLD) were involved in the priming effect by C2-ceramide. However, C2-ceramide inhibited in a dose-related manner the production of O2- induced by phorbol 12-myristate 13-acetate (PMA) and mezerein. Furthermore, PMA-stimulated PLD activity was also significantly reduced by a preincubation of PMN with C2-ceramide. The priming of O2- production by C2-ceramide could involve yet unidentified mechanisms specific for fMLP, or it might imply that cytokines such as TNF-alpha have different mechanisms than C2-ceramide.

Social groups and prevention of preterm births in a population of twin mothers

Prenatal care was equally distributed to all twin pregnant women of the district of Haut de Seine in France in 1989-91, without differences by socio-economic level. No difference in rates of preterm births and very early preterm births (26-31 weeks) was measured by socioeconomic level among twin pregnancies.

[Changes in the high-amplification electrocardiogram after myocardial revascularization. Comparison between coronary artery bypass and angioplasty]

The signal-averaged electrocardiogram (SA-ECG) was studied in 148 patients undergoing myocardial revascularisation either by coronary bypass surgery (CBS) (64 cases) or transluminal angioplasty (PTCA) (84 cases). The investigation was performed before the procedure, at day 7 (D7) and after 3 months (D120). No difference was observed in the SA-ECG between the two groups before revascularisation. The CBS population was older, more symptomatic and had more severe lesions than the PTCA population. One hundred and thirty-nine patients were followed up until the end of the study protocol (CBS = 63; PTCA = 76). Two criteria of the SA-ECG were significantly modified after CBS: QRS duration (p < 0.05) and Under 40 (p < 0.01). No significant changes were observed after PTCA. In the patients with late potentials (LP) before revascularisation, the mean value of these criteria (Under 40 and Last 40) were significantly modified after CBS (U40 = 54.3 +/- 16 to 35.4 +/- 15; p < 0.01) (L40 = 11.9 +/- 4.7 to 26.1 +/- 24.3; p < 0.01). No changes in these criteria were observed after PTCA. The value of negativation of the criteria of LP for patients with two criteria of positivity was 71.1% after CBS compared with 25% after PTCA (not significant). These observations support the hypothesis of a favourable modification of the arrhythmogenic substrate after myocardial revascularisation, especially by CBS.