Plasma channels produced by a laser-triggered high-voltage discharge

A plasma waveguide scheme for high-intensity laser guiding with densities and lengths suitable for laser-plasma particle accelerators is presented. This scheme uses a laser-triggered high-voltage discharge, presents negligible jitter, allows full access to the plasma, and can be scaled to large distances. Experimental results showing the feasibility of this scheme are presented.

Identification of antibodies to Leishmania silent information regulatory 2 (SIR2) protein homologue during canine natural infections: pathological implications

Dogs are the domestic reservoir of zoonotic visceral Leishmaniasis caused by Leishmania infantum in the Mediterranean basin and thus constitute an important health problem in both human and veterinary medicine. Until vaccines become available, conventional measures such as epidemiological surveillance including reservoir control will be among the practical options for prevention and containment of the disease. We have recently characterised novel Leishmania sp. genes encoding parasite proteins named (LmS3a: homologous to mammalian ribosomal protein S3a; LmSIR2: homologous to the silent information regulatory 2 protein family; LimTXNPx: homologous to the peroxiredoxin family with N-terminal mitochondrial leader sequence) that may contribute to the host immune dysfunction in murine experimental Leishmaniasis. In the present study we have investigated the humoral responses against the parasite antigens in groups of L. infantum-infected dogs with different clinical status: symptomatic and asymptomatic with DTH positive or negative test. The determination of immunoglobulin (Ig) isotypes revealed high levels of total IgG in both symptomatic and asymptomatic animals when compared to IgM. Furthermore, the IgG2 appeared to be the predominant subclass of Ig present in the sera of infected animals particularly in the case of symptomatic dogs. The IgG subclass reactivity analysis revealed a broad specific recognition range of parasite recombinant antigens. Interestingly, differential profiles of IgG1 and IgG2 antibody reactivity were observed in asymptomatic and symptomatic dogs. The LmSIR2 protein was found to be a highly reactive molecule with IgG2 from most of the asymptomatic and symptomatic animals. Considering the fact that LmSIR2 secreted by the parasites can be bound and taken up by neighbouring cells, the latter could be a target for anti-LmSIR2 antibodies and this may contribute to the immunopathological alterations and host tissue damage. The implications of these observations in the pathogenesis of Leishmaniasis are discussed.

Evaluation of behavioral states among morning and evening active healthy individuals

The Horne-Ostberg questionnaire partly covers some factors that may be important determinants of peak time and characterize patterns of behavior. We conducted a study for the evaluation of self-reported behavioral states (hunger sensation, availability for study, physical exercise, solving daily problems, and time preferences) as expressions of underlying cyclic activity. Three hundred and eighteen community subjects without history of medical, psychiatric, or sleep disorders were evaluated in a cross-sectional design. A self-report about daily highest level of activity was used to categorize individuals into morning, evening, and indifferently active. Time-related behavioral states were evaluated with 23 visual analog questions. The responses to most analogic questions were significantly different between morning and evening active subjects. Logistic regression analysis identified a group of behaviors more strongly associated with the self-reported activity pattern (common wake up time, highest subjective fatigue, as well as wake up, bedtime, exercise and study preferences). These findings suggested that the patterns of activity presented by normal adults were related to specific common behavioral characteristics that may contribute to peak time.

Leishmania infantum MON-98: infection in a dog from Alto Douro, Portugal

We report the isolation of Leishmania infantum zymodeme MON-98 in Portugal, its first known occurrence outside the focus of El Agamy, Egypt. One dog found to be infected with Acanthocheilonema dracunculoides during a survey of canine filariosis in the Alto Douro region, north-east Portugal, was also discovered to have Leishmania in bone marrow. The isolated strain was identified by isoenzyme analysis. A search for other possible cases of L. infantum MON-98 infection in dogs, vectors and particularly humans is necessary to establish the real epidemiological importance of this zymodeme in the endemic region of Alto Douro.

Mitral valve repair. Quadrangular resection of the posterior leaflet in patients with myxomatous degeneration

OBJECTIVE

To analyze the immediate and late results of mitral valve repair with quadrangular resection of the posterior leaflet without the use of a prosthetic ring annuloplasty.

METHODS

Using this technique, 118 patients with mitral valve prolapse who underwent mitral repair from January '84 through December '96 were studied. Age ranged from 30 to 86 (mean = 59.1 +/- 11.8) years and 62.7% were males. An associated surgery was performed in 22% of the patients, and coronary artery bypass graft was the most frequently performed surgery (15 patients--12.7%). In 20 (16.9%) patients other associated techniques of mitral valve repair were used and shortening of elongated chordae tendineae was the most frequent one (6 patients).

RESULTS

Immediate mortality was 0.9% (one patient). Long-term rates for thromboembolism, endocarditis, reoperation and death in the late postoperative period were 0.4%, 0.4%, 1.7% and 2.2% patients/year, respectively. The actuarial curve of survival was 83.8 +/- 8.6% over 12 years; survival free from re-operation was 91.8 +/- 4.3%, free from endocarditis was 99.2 +/- 0.8% and free from thromboembolism was 99.2 +/- 0.8%. In the late postoperative period, 93.8% of the patients were in functional class 1 (NYHA), with a complete follow-up in 89.7% of the patients.

CONCLUSION

Patients with mitral valve prolapse who undergo mitral valve repair using this technique have a satisfactory prognosis over 12 years.

Use of a leishmanin skin test in the detection of canine Leishmania-specific cellular immunity

The leishmanin skin test was used to detect Leishmania-specific cellular immunity in asymptomatic dogs from an endemic region of visceral leishmaniosis. The test was safe since no clinical signs of intolerance to leishmanin were detected during 1 month, in 14 dogs after inoculations of 3 x 10(8) promastigotes/ml. In another group of four dogs no cross reactivity was found after inoculations of a PPD which demonstrated the specificity of the test. In the same group of animals, repeatability was assessed by repeated inoculations of leishmanin at 1-5-month intervals and the threshold of sensitivity was the concentration of 3 x 10(6) promastigotes/ml. Secondly, we applied the test in a dog population that live in an endemic region of visceral leishmaniosis and found a significant increase in Leishmania-infected dogs after the application of this test in the field.

[Intestinal obstruction after child abdominal surgery (author's transl)]

From 1957 to 1978, 211 intestinal obstructions were treated at Hôpital des Enfants malades, Paris: 103 coming from our own surgery, 108 from other surgical centers. 24,6% cases are observed in children less than one year old, after neo-natal surgery. 41% are observed between 5 and 9 years of age, at the "appendicitis period". 61% obstructions follow an appendicectomy. 74% of obstructions happen in the first year after surgery, of which 32% in the first month (the early mechanical intestinal obstruction between 8 days and 7 years after the first obstruction: 72% in the first year, of which 30,5% within the first month. Some precisions are given about clinical symptoms, site and intestinal lesions. The study of the preventive surgical procedures (Noble's, or Child-Philip's technics) are not included in this paper.