Excitation with effective subcycle laser pulses.

We have used laser pulses with a temporally shaped polarization to demonstrate the multiphoton excitation of the xenon 5g state within a subcycle of a laser pulse. Our polarization gated laser pulses are composed of circularly polarized sections at the leading and trailing edges of the pulse and of an experimentally defined linearly polarized central part. Only the linear part (the gate) of the pulse can excite neutral xenon in the 5g state. The transition cannot be driven with circularly polarized light because the number of photons needed would cause a violation of selection rules for the change of the magnetic quantum number. We show that the linearly polarized central part can be reduced to a subcycle pulse. This allows us to study excitation with an effective pulse as short as 2.3 fs at 800 nm. Electron imaging spectroscopy has been used to visualize the presence of excited states as a function of the pulse duration of the gate.

Ceramide mediates nanovesicle shedding and cell death in response to phosphatidylinositol ether lipid analogs and perifosine.

Anticancer phospholipids that inhibit Akt such as the alkylphospholipid perifosine (Per) and phosphatidylinositol ether lipid analogs (PIAs) promote cellular detachment and apoptosis and have a similar cytotoxicity profile against cancer cell lines in the NCI60 panel. While investigating the mechanism of Akt inhibition, we found that short-term incubation with these compounds induced rapid shedding of cellular nanovesicles containing EGFR, IGFR and p-Akt that occurred in vitro and in vivo, while prolonged incubation led to cell detachment and death that depended on sphingomyelinase-mediated generation of ceramide. Pretreatment with sphingomyelinase inhibitors blocked ceramide generation, decreases in phospho-Akt, nanovesicle release and cell detachment in response to alkylphospholipids and PIAs in non-small cell lung cancer cell lines. Similarly, exogenous ceramide also decreased active Akt and induced nanovesicle release. Knockdown of neutral sphingomyelinase decreased, whereas overexpression of neutral or acid sphingomyelinase increased cell detachment and death in response to the compounds. When transferred in vitro, PIA or Per-induced nanovesicles increased ceramide levels and death in recipient cells. These results indicate ceramide generation underlies the Akt inhibition and cytotoxicity of this group of agents, and suggests nanovesicle shedding and uptake might potentially propagate their cytotoxicity in vivo.

Non-radially polarized THz pulse emitted from femtosecond laser filament in air.

Femtosecond laser filament could produce THz wave in forward direction. In our experiment, THz pulse emitted from a femtosecond laser filament has been investigated. It was found that the polarization of the studied THz pulse mainly appears as elliptical. This observation supplements the previous conclusion obtained by C. D'Amico et al. that THz wave emitted by a filament is radially polarized. The mechanism of generating elliptically polarized THz wave has been interpreted by either four-wave optical rectification or second order optical rectification inside the filament zone where centro-symmetry of the air is broken by the femtosecond laser pulse.

Factors that predict conversion in 69 consecutive patients undergoing laparoscopic ileocecal resection for Crohn's disease: a prospective study.

PURPOSE: This prospective study was designed to identify factors that could predict conversion in patients undergoing first laparoscopic ileocecal resection for Crohn's disease. METHODS: Between 1998 and 2004, 69 consecutive patients (32 males; mean age, 32 +/- 9 years) who had undergone a first laparoscopic ileocecal resection for Crohn's disease were included in a prospective study. Twenty-one patients (30 percent) were converted into laparotomy. Possible factors for conversion were analyzed by both univariate and multivariate analyses. RESULTS: No patient died. Four patients (9 percent; 2 in each group) required five reoperations because of intraperitoneal hemorrhage (n = 1), anastomotic fistula (n = 3), and small-bowel obstruction (n = 1). Mean hospital stay was significantly increased in converted compared with laparoscopic patients (9 +/- 4 vs. 7 +/- 3 days; P < 0.05). On univariate analysis, more than three episodes of acute flare of Crohn's disease (P = 0.02), male gender (P = 0.03), preoperative immunosuppressive drugs (P = 0.04), intra-abdominal abscess or fistula at the time of laparoscopy (P = 0.02), and resection of other intestinal segment (P = 0.02) were factors that predicted conversion. On multivariate analysis, recurrent medical episodes of Crohn's disease (odds ratio, 2; 95 percent confidence interval, 1-4), and intra-abdominal abscess or fistula at the time of laparoscopy (odds ratio, 15; 95 percent confidence interval, 4-78) were the two independent risk factors for conversion. CONCLUSIONS: This prospective study demonstrated that the severity of the disease increased significantly the conversion rate of the first laparoscopic ileocecal resection. Knowledge of these risk factors for conversion could be helpful in preoperative preparation and counseling of patients.

Complete rectal prolapse in young patients: psychiatric disease a risk factor of poor outcome.

OBJECTIVE: Complete rectal prolapse is rare before the age of 50. The aim of our study was to identify the risk factors of total rectal prolapse before this age and to determine the surgical outcome in this specific group of patients. PATIENTS AND METHODS: The charts of all patients, younger than 50 years old, treated for total rectal prolapse between June 1995 and December 2001 were reviewed. Associated conditions were noted and pre and postoperative functions were compared in regards of constipation and evacuations problems, anal continence (Wexner score), recurrent prolapse and overall satisfaction. All patients underwent an abdominal rectopexy according to the Orr-Loygue procedure. RESULTS: During the study period, 28 patients (21 females) with a mean age of 34 +/- 9 years were treated for a total rectal prolapse in our institution. Five patient (17.8%) had minor complications. After a mean follow up of 25 months, the global continence improved significantly (Wexner score: 4.9 vs 2; P = 0.014): 8 patients suffering from liquid stools incontinence before surgery were continent after rectopexy, while 2 continent patients became incontinent to liquid stools after surgery. Fourteen patients had chronic psychiatric disease requiring permanent treatment. These patients suffered more frequently from constipation (12/14 vs 5/14; P =0.006) and required more often a digital evacuation before surgery (6/14 vs 1/14; P = 0.07) than non psychiatric patients. They also suffered from more severe constipation and required more enemas after surgery (1/14 vs 6/12; P = 0.03) compared to patients without psychiatric disease. The only two patients, who had recurrence also had psychiatric disease. CONCLUSION: Chronic psychiatric disease requiring long-term medication is observed in 50% of patients with total rectal prolapse under the age of 50 years. Moreover, the medically induced constipation in these patients could represent a cause of poorer functional outcome. Therefore, we recommend the identification of this preoperative risk factor to assess the results of total rectal prolapse treatment in patients younger than 50 years of age.

Use of alternative medicines in diabetes mellitus.

AIMS: Enormous advances have been made in medical care but more people are still using herbal or alternative remedies. In chronic conditions such as diabetes patients may turn to alternative remedies that have been purported to improve glycaemic control. This study surveyed diabetic and control subjects about their use of all prescribed medication, over-the-counter supplements, and alternative medications. METHODS: Subjects were prospectively contacted in person or by telephone. Five hundred and two diabetic subjects and 201 control subjects were asked to provide details about themselves, their diabetes (for the diabetic subjects) and their use of prescribed medication, over-the-counter supplements and alternative medications. Subjects were asked to rank their assessment of the effectiveness of each medication. Costs were calculated on a per month basis from average prices obtained from five alternative health stores and five chemist shops. RESULTS: Of the diabetic subjects, 78% were taking prescribed medication for their diabetes, 44% were taking over-the-counter supplements and 31% were taking alternative medications. Of the control subjects, 63% were taking prescribed medication, 51% were taking over-the-counter supplements, and 37% were taking alternative medications. Multivitamins, vitamin E, vitamin C, calcium and aspirin were the most commonly used over the counter supplements. Garlic, echinacea, herbal mixtures, glucosamine were the most commonly used alternative medications. Chromium was used only by diabetic subjects and then only rarely. Subjects rated the effectiveness of the alternative medications significantly lower than for prescribed medications but still thought them efficacious. Alternative medications purported to have some hypoglycaemic effect were little used by diabetic subjects. Diabetic subjects spent almost as much money on over-the-counter supplements and alternative medications together as they did on their diabetic medications. CONCLUSIONS: One-third of diabetic patients are taking alternative medications that they consider efficacious but this is no more than in the control group. The money spent on alternative and non-prescription supplements nearly equals that spent on prescription medications. In view of the money spent in this area the time is past due to evaluate these remedies and to establish what merit they have.

Toward a better prescription of the prone back extension exercise to strengthen the back muscles.

This study investigated the level of resistance and the level of muscle activation of the prone back exercise. Fifteen male subjects with no previous history of low back injury performed two repetitions of seven exercises. These consisted of four maximal isometric voluntary contractions (MVC) and three prone back extension (PBE) exercises. The subject was lying prone on a table, the upper body was suspended off the end of the table and the legs and thighs were secured to the table with straps. Three starting positions from the horizontal were investigated, 0 degree, 30 degrees and 60 degrees, and were compared with MVC to quantify the level of effort needed to perform the task. The results showed that the three PBE exercises require a level of resistance and a level of muscle activation generally under 40% of the maximum capacity of healthy subjects. Muscle activity of the erector spinae (ES) was slightly greater when the exercise started at 60 degrees, compared to 0 degree and 30 degrees. During the static phase of the PBE exercises, the level of resistance remained at 40% relative to the peak reaction moment of the MVC, but muscular activity of ES tended to work at a lower activity level. In conclusion, since for healthy subjects PBE exercises are low resistance exercises, they seem to be more specifically designed to develop muscular endurance of the back muscles.

[Treatment of peritonitis in continuous ambulatory peritoneal dialysis with intraperitoneal ceftriaxone]. / Traitement des péritonites en dialyse péritonéale continue ambulatoire par la ceftriaxone intrapéritonéale.

In 16 patients under CAPD, 29 cases of bacterial peritonitis were observed, with clinical manifestations in 23. The mean cell count in peritoneal dialysis fluid was 5608/mm3 with 4991/mm3 polymorphonuclear, Leukocytes Causative pathogens were Staphylococcus in 14 cases, Streptococcus in 6, Bacillus in one, Enterobacteria in 5, Pseudomonas aeruginosa in 1 and Moraxella in 1. Three cultures were negative. First choice treatment was a daily intraperitoneal injection of 1 g of ceftriaxone. 79.3% of patients recovered within 5 days. Failure were due to a Methicillin-resistant Staphylococcus epidermidis in one case, a Streptococcus faecalis in two cases, and a Staphylococcus aureus in three observations, which two were responsible of abscess round catheter peritoneal. Mean ceftriaxone concentrations 24 hours after the intraperitoneal injection were 50.6 mg/l (range: 3.3-141 mg/l) in serum and 58.1 mg/l (range: 4.3-180 mg/l) in dialysate. These concentrations are greater than most of ceftriaxone's MICs for susceptible bacteria, a finding that confirm the value of treatment with a single daily intraperitoneal injection of ceftriaxone.

[Treatment of peritonitis due to continuous ambulatory peritoneal dialysis using a single daily intraperitoneal dose of 1g cefotiam]. / Traitement des péritonites en dialyse péritonéale continue ambulatoire par une dose unique quotidienne de 1g de céfotiam par voie intrapéritonéale.

Peritonitis remains the main complication of CAPD. This study demonstrates that most cases can be successfully treated with cefotiam. In 17 patients under CAPD, 33 cases of bacterial peritonitis were observed, with clinical manifestations in 28. The mean cell count in peritoneal dialysis fluid was 2 820/mm3, with 2 200/mm3 polymorphonuclear leukocytes. Causative pathogens were Staphylococcus in 18 cases, Streptococcus in 4, Stomatococcus mucilaginous in 1, Corynebacterium J.K. in 1, Enterobacter in 3, Acinetobacter in 3 and Pseudomonas in 2. Two cultures were negative. First choice treatment was a daily intraperitoneal injection of 1 g cefotiam. 68.80% of patients recovered within 6 days. Failures were due to a methicillin-resistant Staphylococcus epidermidis in 3 cases, a relapsing Stomatococcus mucilaginous infection in 1, a Streptococcus faecalis in 1, an Acinetobacter in 3 and a Pseudomonas in 2. Mean cefotiam concentrations 24 hours after the intraperitoneal injection were 9.4 +/- 7.0 micrograms/ml (range 1.3-26.4 micrograms/ml) in serum and 3.4 +/- 3.3 micrograms/ml (range 0.4-12.2 micrograms/ml) in dialysate. These concentrations are greater than most of cefotiam's MICs for susceptible bacteria, a finding that confirms the value of treatment with a single daily intraperitoneal injection of cefotiam.

[Epidemiology of filariasis (onchocerciasis and bancroftosis) in the Tala-Mokolo region (Mandara Mountains of North Cameroon)]. / Epidémiologie des filarioses (onchocercose et bancroftose) dans la région de Tala-Mokolo (Monts Mandara-Nord Cameroun).

The effect of the bancroftian filariasis on the health of the inhabitants are minimal in the study area, where the prevalence of the disease (nocturnal microfilaremia) is 0.4% only. But skin snips harboring Onchocerca microfilariae are seen in 12.1% of the sample studied. Onchocerciasis skin lesions, low visual acuity and blindness are often seen in the villages where the prevalence is high, among inhabitants more than 40 years of age. Simulium damnosum is seldom seen in the area, except in the large streams and rivers like the mayo Tsanaga and the mayo Djingliya. Larvae and nymphae of this species hardly succeed in developing on the overspelling of the small dams, this being due more to a discontinuous run of the water in the overspilling than to a to high speed of the water.