Enhanced photoemission from laser-excited plasmonic nano-objects in periodic arrays.

The process of photoelectron emission from gold surfaces covered with nano-objects that are organized in the form of a periodic array is addressed in the short laser pulse regime ([Formula: see text] fs) at moderate intensities [Formula: see text] W cm(-2) and for various laser wavelengths. The emission spectrum from a gold single crystal measured under the same conditions is used for reference. The comparison of the photo-emission yield and the energy of the ejected electrons with their counterparts from the (more simple) reference system shows that the periodic conditions imposed on the target surface drastically enhance both quantities. In addition to the standard mechanism of Coulomb explosion, a second mechanism comes into play, driven by surface plasmon excitation. This can be clearly demonstrated by varying the laser wavelength. This interpretation of the experimental data is supported by predictions from model calculations that account both for the primary quantum electron emission and for the subsequent surface-plasmon-driven acceleration in the vacuum. Despite the fact that the incident laser intensity is as low as [Formula: see text] W cm(-2), such a structured target permits generating electrons with energies as high as 300 eV. Experiments with two incident laser beams of different wavelengths with an adjustable delay, have also been carried out. The results show that there exist various channels for the decay of the photo-emission signal, depending on the target type. These observations are shedding light on the various relaxation mechanisms that take place on different timescales.

Investigation of laser-irradiated Ar cluster dynamics from K-shell x-ray emission measurements.

Intense (up to a few 10(17) W/ cm2) femtosecond (down to 40 fs) laser pulses are focused onto a partially clusterized argon gas jet. The target was previously characterized and optimized in order to get a homogeneous and dense jet of clusters with a well controlled size. The interaction leads to x-ray emission that is absolutely calibrated and spectrally resolved using a high resolution time-integrated spectrometer in the K-shell range (from 2.9 to 4.3 keV). X-ray spectra are investigated as a function of different laser temporal parameters such as the nanosecond prepulse contrast, the laser pulse duration, and the femtosecond delay between two different laser pulses. The cluster size ranges from 180 to 350 angstroms and irradiation by laser pulses with both linear and circular polarization is investigated. The experimental results are discussed in terms of the laser-cluster interaction dynamics. They are compared with the predictions of collision-dominated nanoplasma models. However, further interaction processes are required in order to explain the observed characteristic lines demonstrating highly charged ions up to Ar16+.

A method to recover, enumerate and identify lymphomyeloid cells present in an inflammatory dermal site: a study in laboratory mice.

We describe a new method to recover and study cells present in the dermis of mouse ear at homeostasis or after intradermal injection of disturbing agents (lipopolysaccharide or Listeria monocytogenes). The ears either left untreated or inoculated were handled and processed as culture explants of the dorsal and ventral leaflets, their dermal sides being spread on a buffered medium. Within this medium emigrate/sediment, with different kinetics: neutrophils, mononuclear phagocytes, dendritic leucocytes, T lymphocytes expressing either gamma delta or alpha beta TCRs, and other minor subsets, the identification of which deserves more relevant reagents: they are likely to be NK, mast cells, eosinophils and their local progenitors. All the major subsets were identified through a combination of immunocytochemical and flow cytometry labeling. Two examples illustrating the advantages and limitations of this new method are given: either 1 microgram of LPS or 10(4) Listeria monocytogenes were injected within the ear 48, 24, 12, 6, 3 h before ear explant culture. This ear explant culture has been further compared to the ear sheet treatment with collagenase/disease for three cell populations, the epidermal dendritic leucocytes, the gamma delta epidermal T cells as well as the alpha beta T cells recirculating within the steady state dermis. This method provides the first evidence of the existence of recirculating T CD4 lymphocytes in the mouse dermis.

Isolation and flow cytometric analysis of the free lymphomyeloid cells present in murine liver.

Recruitment of circulating lymphomyeloid cells in the liver during infection often plays a critical role, mediating control or exacerbation of the pathogen growth. This paper describes a simple and rapid technique to recover these lymphomyeloid cells from a normal or an infected liver. After portal perfusion with saline buffer, the liver is gently dissociated on steel screens and the resulting cell population spun in 35% Percoll in 100 IU/ml Calciparine to remove all nuclei and cell debris: the recovery of a pure liver lymphomyeloid cell population is usually achieved in 40-60 min. Phenotypic and functional analysis could then be easily carried out on this cell population. This methodology was applied to normal mouse liver: flow cytometric analysis of the purified free lymphomyeloid cells showed the presence of T lymphocytes (46% +/- 3 with a CD4/CD8 ratio of 2.8), B lymphocytes (20% +/- 2 IgG and 30% IgM positive) and myelomonocytic cells (14% +/- 2 complement receptor type III positive).

Manipulating blood T cells and B cells from squirrel monkeys: some technical considerations.

The squirrel monkey Saimiri sciureus is an experimental host for a range of human pathogens, and for the assessment of vaccine candidate antigens and vaccine strategies. This experimental host is thus particularly suitable for the follow-up of humoral responses. To understand some of the mechanisms that underlie the defense against experimental pathogens, there is a need of basic knowledge on cellular immune effectors also. The authors report here their experience in characterizing squirrel monkey blood T and B lymphocytes, and in studying in vitro induced activation and proliferation of T and B cells. Particular emphasis is given to the in vitro differentiation of squirrel monkey B cells into immunoglobulin secreting cells, with respect to Plasmodium falciparum antigens.

Flow cytometry detection of surface antigens on fresh, unfixed red blood cells infected by Plasmodium falciparum.

The immunofluorescence detection of parasite-specific antigens on the surface of red blood cells infected by Plasmodium falciparum parasites is usually performed by visual detection under a fluorescence microscope. We describe here a technique permitting the analysis of surface immunofluorescence labelling by flow cytometry. Infected red blood cells are selected on the basis of their parasitic DNA and RNA content by Hoechst and Thiazole Orange vital dyes. Cytometric analysis of these labels, as well as general erythrocyte characteristics assessed by analysis of forward and side scatter allows the selection of viable intact infected erythrocytes from other blood cells. The integrity of these selected erythrocytes was confirmed by the absence of labelling with antibodies directed against internal components such as spectrin. This technique permits the detection of specific surface immunofluorescence staining on red blood cells infected with mature stages of P. falciparum by antibodies in sera from hyperimmune Saimiri monkeys. Using Thiazole Orange dye for detection of parasitised cells, this analysis was performed on a FACSscan apparatus equipped with a single laser.

Three-flap anoplasty for imperforate anus: results for primary procedure or for redoes.

UNLABELLED: Three-flap anoplasty was first described in 1987 by Yazbeck for the treatment of rectal prolapse after pull-through operations for imperforate anus, and in 1992 in a case of anterior perineal approach. It is intended to reproduce the normal anatomy of a sensitive anal canal. The purpose of this study is to evaluate 14 children (9 boys and 5 girls) operated for imperforate anus. METHOD: Eleven children had an intermediate or high imperforate anus and 3 had a low imperforate anus. Nine were operated for the first time with a three-flap anoplasty (GrA), and 5 were reoperated with this technique because of fecal incontinence and/or rectal prolapse (GrB). Seven patients had associated malformations: one Hirschsprung's disease, one cloacal defect with renal insufficiency, three complex caudal malformations with tethered cord, one Down syndrome, and two psychological and psychomotor troubles. The patients (average age = 6 years) have been evaluated every year since 1997, with a questionnaire based on a clinical score validated with 30 healthy children, used as a control group. Ten anal manometries were carried out. RESULTS: In 1998, the GrA score was 16.1 (control = 22.5) and the GrB score was 11.5 (p = 0.25). In 1999, GrA and GrB score were approximately the same. The score of those without associated anomalies was 19.6 whereas the score of the children with other malformations or anomalies was 10 (p = 0.02). Anal manometry is almost normal in patients with low or intermediate imperforate anus (rectoanal relaxation reflex for 10 cm H2O, and basal resting pressure more than 40 cm H2O). Even though anal manometry is subnormal in patients with Down syndrome or psychomotor troubles, the clinical score remains low (score = 10). In cases of complex caudal malformations or high imperforate anus, the results of anal manometry and clinical score are bad (score 9.7). CONCLUSION: The three-flap anoplasty can be carried out in newborns without colostomy and often represents the only possible surgical approach to avoid a laparotomy. This plasty, proposed secondarily to correct a defect of continence, can be performed without colostomy, with satisfactory results.

[Esophagogastroduodenal localizations of Crohn's disease are frequent]. / Les localisations oesogastroduodénales de la maladie de Crohn sont fréquentes.

The purpose of this study was to determine the endoscopic features, actual frequency and consequences of upper digestive involvement in Crohn's disease (CD). Between April 1973 and April 1985, one or several upper digestive tract endoscopies with biopsies were performed in 129 of 195 patients admitted for ileal and/or colorectal CD. Endoscopic lesions were small and superficial: aphtous and superficial ulcerations, or erythematous areas. The diagnosis of upper digestive involvement was probable in 36 of the 129 patients who underwent upper endoscopies (28 p. 100), certain (microscopic evidence of granuloma) in 21 patients (16 p. 100). Lesions were isolated or multifocal but their preferential sites were the antrum and proximal duodenum. Histologic study of biopsies showed that granuloma were as frequent in upper as in lower intestinal lesions of CD. A frequency of 20 p. 100 seems to us to be more correct than the 5 p. 100 usually admitted. In our experience, upper digestive involvement in CD could not be regarded as a pejorative prognostic factor. It was sometimes possible to identify colitis or a peptic ulcer disease as a lower or upper digestive manifestation of CD, respectively.

[Specific gastric localization of Wegener's disease]. / Localisation gastrique spécifique de la maladie de Wegener.

We report an unusual gastric ulcer disease in a 52 year old white man which relapsed despite antacids and anti-H2 treatment. During the course of the disease, fever, weight loss, and ocular, oropharyngeal as well as systemic manifestations occurred. Gastric biopsies were normal until macrobiopsy was performed 5 months later demonstrating necrotizing granulomatous vasculitis. Further identical oropharyngeal mucosal lesions and a pulmonary infiltrate occurred supporting the diagnosis of Wegener's disease. The subsequent course was complicated by a massive hemorrhage which required total gastrectomy. Despite specific treatment with cyclophosphamide and steroids, the patient died. Most of the gastrointestinal lesions consistent with Wegener's disease are usually found at necropsy. Clinical gastrointestinal manifestations are scarce and rarely due to the underlying disease. Prognosis depends upon the renal lesions. However, as well, involvement of the digestive tract seems to be a factor of poor evolution of the disease.

[Congenital cystic dilatation of the common bile duct, anomaly of the biliopancreatic junction and cancer of the bile ducts]. / Dilatation kystique congénitale du cholédoque, anomalie de la jonction bilio-pancréatique et cancer des voies biliaires.

The choledochus and pancreatic duct ordinarily enter the duodenum either separately or via a common channel located in the duodenal wall. The usual maximal length of the common channel is approximately 0.5 cm. An anomalous junction of the pancreaticobiliary tract is defined by the presence of an unusually long common channel whose length is 1 cm or longer. During the last 8 years, we studied 9 cases of congenital dilatation of the bile duct. Besides the choledochal cyst, all patients had a common channel which measured 1.5 cm or longer. The mean age of patients (6 females, 3 males) was 36.5 years. Three patients had extrahepatic bile tract carcinoma. One patient, a 51-year old man, had gallbladder carcinoma without stones while the two other patients, a 43-year old woman and a 32-year old man, had carcinoma arising from the wall of the cystic dilatation. These two patients had undergone a simple internal drainage procedure 16 and 8 years before, respectively. Our study suggests that the anomalous junction of the pancreaticobiliary tract, an embryonic anomaly which allows the reflux of pancreatic juice into the bile duct and gallbladder, may be responsible for congenital bile duct dilatation and biliary tract carcinoma. Total excision of the cystic dilatation and the gallbladder with hepaticojejunostomy is the appropriate surgical treatment.

[Socioprofessional consequences of Crohn disease]. / Répercussions socio-professionnelles de la maladie de Crohn.

To evaluate evolutivity and social repercussions of Crohn's disease, the same gastroenterologist interviewed 151 out of 197 patients with Crohn's disease (77.5 percent) who had been hospitalized from 1964 to 1986 in our unit. The other 46 could not be traced or refused to participate. There was no difference regarding age, sex, duration of illness, pattern of lesions and operations between the two groups. At the time of observation, mean follow-up was 7.8 years and two thirds of the patients had inactive disease. During the previous year, the course of the disease was quiescent in 50 percent of all patients; this rate increased with duration of follow-up and time from surgery. A constant rate of stable course was observed (20 percent) irrespective of duration of disease and time of surgery. The interviews were compared with those obtained from an age and sex-matched group of 70 previously healthy subjects admitted to the hospital for less than one month. The education and socioeconomic levels were higher in patients with Crohn's disease than in controls, in spite of the fact that 25 percent of patients whose disease begun during scholarship complained of difficulties at school, and nearly 20 percent of all patients were partially or totally unable to work. Sports and cultural activities were the same in Crohn's disease and in the control group. Tobacco intake was slightly higher at time of diagnosis but it was equal in both groups at the time of the interview. Non allopathic advice or treatment were sought by 48 percent of Crohn's disease patients (7 percent in controls).(ABSTRACT TRUNCATED AT 250 WORDS)

[Anorectal manometry and ileo-anal anastomosis]. / Manométrie ano-rectale et anastomose iléo-anale.

Seventeen patients (12 ulcerative colitis, 5 familial adenomatous polyposis) underwent proctocolectomy and ileal J pouch anastomosis. Anal manometry with determination of maximum tolerable volume and a liquid continence test were perform before ileo-anal anastomosis, before closure of the loop ileostomy and 12 months after closure of the loop ileostomy. All patients were continent during the daytime less 12 months after proctocolectomy. The mean stool frequency was 5 stools per day in our 17 patients. A significant increase in maximum tolerable volume and in the liquid continence test was observed during the first year after closure of the ileostomy. Anal manometry is unnecessary after ileoanal anastomosis, but preoperatively, this test is able to exclude some patients with low anal pressure.

[Corneoscleral involvement in Crohn's disease. Discussion of a case]. / Atteintes cornéo-sclérales au cours de la maladie de Crohn. Discussion d'une observation.

The authors are reporting an unusual case of scleral involvement in a case of Crohn's disease. A distinctive subepithelial keratopathy developed which though uncommon, should be regarded as a distinct clinical sign of Crohn's disease. The exact situation of ocular lesions among extra-intestinal complications of Crohn's disease, their incidence and aspects are discussed. The possible immunological basis of these manifestations, still unconvincing, is exposed and related to local deposition of antigen-antibody complexes.

[Determination of acceptability of 2 cutaneous estradiol gels, in a dose of 1.5 mg daily]. / Appréciation de l'acceptabilité de deux gels d'estradiol cutané, à la dose d'1,5 mg par jour.

OBJECTIVE: The aim was to compare acceptability of a percutaneous 0. 1% estradiol gel (Gel A, Estreva(R) Gel, Laboratoire Théramex, Monaco) to that of an 0.06% estradiol gel (Gel B, Oestrodose(R), Laboratoires Besins-Iscovesco) in its new formulation and packaging. MATERIAL AND METHODS: This randomized, crossed, simple-blind study was carried out in 48 volunteer healthy postmenopausal women. The volunteers applied on one forearm 1.5 mg/day of cutaneous estradiol in the form of either gel, according to randomized allocation, for four days without free period between the two therapeutic periods. The application and drying times of the two gels were measured during the first application; gel subjective women assessment was collected at the beginning and at the end of the study. RESULTS: Mean application and drying times with Gel A are significantly reduced, compared to Gel B (p=0.0259 and p=0.0001, respectively) with drying time 61% shorter; these data are confirmed by subjective women evaluation. The two gels are not significantly different regarding several criteria as consistency, ease of application and sensation of lasting stickiness. However, a significant difference is found in favour of Gel A on the following items: practicality of application (p=0.007), ease of penetration (p<0.001), quantity of gel to apply (p<0.001) after the first application. After four days of administration, a same significant difference is observed concerning practicality of the gel (p=0.0078), duration of use (p<0. 001), packaging, women opinion on the gel (p=0.022) and the product, gel and packaging (p<0.001). At the end of the study, gel A utilization is considered by women more practical (p=0.001) with an easier application (p<0.001) and less restricting while applying (p=0.001), compared to Gel B; 72.9% of women prefer the Gel A and 12. 5% of women prefer the Gel B. CONCLUSION: A better acceptability of the 0.1% estradiol gel and of its packaging compared to that of the 0.06% estradiol gel in this new formulation and packaging is observed in this study.

[Gastroesophageal reflux in asthmatic and chronic bronchitis patients]. / Reflux gastro-oesphagien chez les asthmatiques et les bronchitiques chroniques.

To determine the relationship between gastroesophageal (GE) reflux and pulmonary disease, we studied 21 asthmatics, 30 chronic bronchitics, 6 patients with GE reflux and no pulmonary symptoms, and 10 control subjects; GE reflux was diagnosed by pH monitoring and GE scintiscanning. Frequency of GE reflux in the asthmatics was 57%; in chronic bronchitis it was 56%. Pulmonary function tests did not show any differences between patients with or without reflux. The GE reflux episodes were more numerous but shorter in asthmatics than in chronic bronchitis. Patients with digestive symptoms alone were no different from chronic bronchitis with respect to reflux. The mechanism whereby reflux triggers pulmonary problems was investigated using the following 2 tests: scintiscan for pulmonary aspiration, and esophageal acid infusion (0.1N HCI). Six pulmonary aspirations were detected. Only asthmatics, with or without reflux, showed any significant variations in maximal expiratory flow at 50% and 25% of VC after HCI infusion. Thus, our results show that asthmatics differ from bronchitis patients by the characteristics of their reflux.

Immunogenic properties of Klebsiella pneumoniae type 2 capsular polysaccharide.

The immunoprotective activity of Klebsiella pneumoniae K2 cell surface preparations and purified capsular polysaccharide was tested in mice. The 50% protective dose (PD50), expressed as capsular polysaccharide content, was 2 ng for cell surface preparations and 50 ng for purified capsular polysaccharide. Both preparations lost their immunoprotective activity after alkali treatment. Immune sera were raised in rabbits immunized with cell surface preparations. The precipitating and hemagglutinating capacity of these antisera was tested against either purified capsular polysaccharide or alkali-treated capsular polysaccharide. No difference was observed between the reactivity of the antisera against each antigen. The protective activity of these sera was tested on mice in passive transfer experiments, before and after absorption with either purified capsular polysaccharide or alkali-treated capsular polysaccharide. The sera lost their protective activity after absorption with purified capsular polysaccharide and after absorption with alkali-treated capsular polysaccharide. These experiments show that the difference in immunoprotective activity of cell surface preparations, purified capsular polysaccharide, and alkali-treated capsular polysaccharide is not due to a difference in their antigenic determinants. Cell surface preparations and purified capsular polysaccharide were fractionated by gel filtration on Sepharose 4B and by ultracentrifugation on cesium chloride density gradients. Three forms of capsular polysaccharide have been characterized. (i) A form of capsular polysaccharide with a very high protective activity (PD50 = 2 ng) that copurified with protein and lipopolysaccharide and was characterized by a low coefficient of distribution (Kd = 0.20) and a low density (1.5 to 1.6 g/cm3). (ii) A form of capsular polysaccharide with an intermediate protective activity (PD50 = 50 ng), contamined by less than 3% protein and 1% lipopolysaccharide, with a Kd of 0.35, and a density of 1.7 to 1.8 g/cm3. (iii) A nonimmunoprotective capsular polysaccharide obtained after alkali treatment of either cell surface preparations or purified capsular polysaccharide. The Kd of these fractions varied from 0.20 to 0.90 and their density from 1.7 to 1.8 g/cm3.