First Evidence of Purely Extreme-Ultraviolet Four-Wave Mixing.

The extension of nonlinear optical techniques to the extreme-ultraviolet (EUV), soft and hard x-ray regime represents one of the open challenges of modern science since it would combine chemical specificity with background-free detection and ultrafast time resolution. We report on the first observation of a four-wave-mixing (FWM) response from solid-state samples stimulated exclusively by EUV pulses. The all-EUV FWM signal was generated by the diffraction of high-order harmonics of the FERMI free-electron laser (FEL) from the standing wave resulting from the interference of two crossed FEL pulses at the fundamental wavelength. From the intensity of the FWM signal, we are able to extract the first-ever estimate of an effective value of ∼6×10^{-24} m^{2} V^{-2} for the third-order nonlinear susceptibility in the EUV regime. This proof of principle experiment represents a significant advance in the field of nonlinear optics and sets the starting point for a manifold of techniques, including frequency and phase-resolved FWM methods, that are unprecedented in this photon-energy regime.

Four-wave-mixing experiments with seeded free electron lasers.

The development of free electron laser (FEL) sources has provided an unprecedented bridge between the scientific communities working with ultrafast lasers and extreme ultraviolet (XUV) and X-ray radiation. Indeed, in recent years an increasing number of FEL-based applications have exploited methods and concepts typical of advanced optical approaches. In this context, we recently used a seeded FEL to demonstrate a four-wave-mixing (FWM) process stimulated by coherent XUV radiation, namely the XUV transient grating (X-TG). We hereby report on X-TG measurements carried out on a sample of silicon nitride (Si3N4). The recorded data bears evidence for two distinct signal decay mechanisms: one occurring on a sub-ps timescale and one following slower dynamics extending throughout and beyond the probed timescale range (100 ps). The latter is compatible with a slower relaxation (time decay > ns), that may be interpreted as the signature of thermal diffusion modes. From the peak intensity of the X-TG signal we could estimate a value of the effective third-order susceptibility which is substantially larger than that found in SiO2, so far the only sample with available X-TG data. Furthermore, the intensity of the time-coincidence peak shows a linear dependence on the intensity of the three input beams, indicating that the measurements were performed in the weak field regime. However, the timescale of the ultrafast relaxation exhibits a dependence on the intensity of the XUV radiation. We interpreted the observed behaviour as the generation of a population grating of free-electrons and holes that, on the sub-ps timescale, relaxes to generate lattice excitations. The background free detection inherent to the X-TG approach allowed the determination of FEL-induced electron dynamics with a sensitivity largely exceeding that of transient reflectivity and transmissivity measurements, usually employed for this purpose.

A driving simulator study of driver performance on deceleration lanes.

Deceleration lanes are important because they help drivers transition from high-speed lanes to low-speed ramps. Although they are designed to allow vehicles to depart the freeway safely and efficiently, many studies report high accident rates on exit ramps with the highest percentage of crashes taking place in deceleration lanes. This paper describes the results of a driving simulator study that focused on driving performance while approaching a divergence area and decelerating during the exiting maneuver. Three different traffic scenarios were simulated to analyze the influence of traffic volume on driving performance. Thirty drivers drove in the simulator in these scenarios while data on their lateral position, speed and deceleration were collected. Our results indicate there are considerable differences between the main assumptions of models generally used to design deceleration lanes and actual driving performance. In particular, diverging drivers begin to decelerate before arriving at the deceleration lane, causing interference with the main flow. Moreover, speeds recorded at the end of the deceleration lane exceed those for which the ramp's curves are designed; this creates risky driving conditions that could explain the high crash rates found in studies of exit ramps. Finally, statistical analyses demonstrate significant influences of traffic volume on some aspects of exiting drivers' performance: lower traffic volume results in elevated exiting speed and deceleration, and diverging drivers begin to decelerate earlier along the main lane when traffic volume is low. However, speeds at the end of the deceleration lane and the site of lane changing are not significantly influenced by traffic volume.

The use of ciclosporin in paediatric inflammatory bowel disease: an Italian experience.

AIM: To asses the efficacy and safety of ciclosporin in a paediatric population with inflammatory bowel disease. PATIENTS AND METHODS: Twenty-three Italian children treated with ciclosporin were studied retrospectively. The indications for treatment were severe unresponsive colitis, chronic active colitis or severe fistulizing Crohn's disease. The treatment duration, follow-up and causes of drug discontinuation were assessed. RESULTS: Sixteen patients were treated intravenously for a mean time of 10 +/- 7 days (1-24 days) and 19 orally for a mean time of 133 days (17-660 days). The mean follow-up of all patients was 13.2 months. Ciclosporin was totally ineffective, being discontinued for surgery, in nine of 23 patients (39%); it was discontinued for partial response in three patients (13%). During treatment, clinical remission was achieved in eight children (35%) and maintained after drug withdrawal in four (17%). In severe unresponsive colitis, urgent colectomy was avoided in 12 (85%) of 14 patients who tolerated the drug. Side-effects appeared in six of 23 patients (26%), and three (13%) required ciclosporin to be discontinued due to neurotoxicity. CONCLUSIONS: Ciclosporin shows disappointing long-term results in the treatment of refractory inflammatory bowel disease, but can play an important role in preventing urgent surgery in unresponsive severe colitis. Severe side-effects can occur.

Bloodstream infections can develop late (after day 100) and/or in the absence of neutropenia in children receiving allogeneic bone marrow transplantation.

We retrospectively evaluated the incidence and time from transplantation of bloodstream infections occurring in children receiving bone marrow transplant (BMT) at G Gaslini Children's Hospital between September 1984 and December 1997. During this period the incidence was 35% after allogeneic and 26% after autologous BMT (P=0.08). Among these episodes, 38% after allogeneic BMT and 90% after autologous BMT were detected in the presence of neutropenia within the first 30 days from reinfusion (P < 0.001). Incidence of catheter-related bloodstream infections was 40% after allogeneic and 8% after autologous BMT (P < 0.001). Bloodstream infections in the absence of neutropenia were 55% after allogeneic BMT vs 10% after autologous BMT (P < 0.001) and occurred later after reinfusion (mean 199 vs 41 days, P <0.001). Among the episodes occurring after allogeneic BMT and in the absence of neutropenia, 61% were related to the presence of a central venous catheter, 15% were related to the presence of GVHD, but 23% were not associated with any of major risk factors for infection. Finally, 38% of episodes following allogeneic BMT were detected after day 100 vs 1% after autologous BMT. We concluded that patients receiving allogeneic BMT experience a high incidence of bloodstream infections in the absence of neutropenia and that a significant proportion of these episodes is not clearly associated with well known risk factors such as GVHD or central venous catheters. Moreover, many episodes develop a long time after the transplantation procedure. Therefore, any febrile episode following allogeneic BMT even late and/or in the absence of neutropenia should be intensively managed.

[Sepsis related to a permanent central venous catheter in children with neoplastic disease: practical implications of a continuous surveillance of the etiology]. / Sepsi correlate a catetere venoso centrale a permanenza in bambini affetti da malattia neoplastica: implicazioni pratiche di una sorveglianza continua dell'eziologia.

Indwelling central venous catheter-related bacteremias are an important complication in patients with cancer. In general they are due to Staphylococcus aureus and Candida, while bacteremias caused by Gram-negatives are less common and often related to infusate contaminans. We describe a survey of etiological surveillance of Broviac catheter-related infections at G. Gaslini Children's Hospital of Genoa, Italy. In the period 1989-1992 an increase of Broviac catheter-related bacteremias due to Gram-negatives was demonstrated as compared with previous years (1985-1988). At home parental management was suspected as an important risk factor, since this complication was frequently due to infusate contaminants and no epidemic cluster or positive surveillance culture was observed in the Hospital. Therefore at home management was changed, especially regarding heparin storage. The subsequent, prospective follow-up from July 1993 to December 1995 showed a significant decrease in catheter-related bacteremias due to Gram-negatives (P = 0.003, chi-square test). In conclusion, a strict control on at home catheter management procedures must be maintained in order to reduce the risk of indwelling central venous catheter-related infections in children with cancer.

[Incidence and treatment of local recurrences after conservative surgical treatment for cancer of the breast]. / Incidence et traitement des récidives locales après traitement chirurgical conservateur pour cancer du sein.

Long-term survival is comparable after total mastectomy or conservative surgery for early breast cancer. Our purpose was to evaluate the rate and therapy of breast relapse at the Regional Hospital of Varese (Italy) in a 10 years period. From 1/1/1980 to 31/12/1990 a total of 606 patients with early breast cancer (Stage I or II early) were evaluated. They all were submitted to quadrantectomy, axillary dissection and radiotherapy. In case of metastases to the axillary lymph nodes, hormono or chiotherapy were performed. 425 patients were regularly followed for a period of 2.5-13 years. In 15 patients (3.2%) a local recurrence was discovered. They were treated as follows, 8 patients: mastectomy, 4 patients: conservative surgery, 4 patients: no therapy. The surgical approach of the local recurrence, mastectomy or conservative surgery, does not influence long-term survival of patients treated with conservative surgery and radiotherapy for early stage breast cancer. Conservative surgery is often possible in treating local recurrence without interfering with complete removal of the tumor and long-term survival.

Factors related to drug consumption during pregnancy.

A survey on drug intake during pregnancy was carried out in a sample of 3268 women who delivered live-born infants in 11 hospitals located throughout Italy. A large questionnaire on drug use and other aspects of maternal life-style was administered within five days of delivery to 3112 women who consented to the interview. An overall mean consumption of 2.17 drugs per woman was reported. Apart from dietary supplements, the most used drugs were tocolytics, analgesics, and antibiotics. The proportion of women who did not use any drug was 17.3%. The role of some non-medical determinants of drug intake was evaluated as well. Geographic and socio-economic factors were seen to increase drug intake up to 44%, while the presence of anxiety provoked a 60% higher consumption of drugs other than dietary supplements. Other factors influencing drug use during pregnancy were rural vs. urban residence and smoking habits. The need for the recording of these socio-economic factors in surveys on drug use during pregnancy is emphasized.

Moderate maternal drinking and outcome of pregnancy.

The adverse effect of light or moderate maternal drinking during pregnancy on the well being of the newborn has been investigated. The study group included 2145 live births in the obstetric units of 11 Italian cities between February 1989 and July 1990. A detailed life style questionnaire was administered to the mothers. Information on the newborn was collected from clinical records as well as from a clinical examination. Both univariate and multivariate analyses were suggestive of a decrease in mean birth weight associated with maternal drinking pregnancy, especially in women who also smoked during pregnancy. This effect was higher in male newborns. The occurrence of low birth weight (< 2500 g.) was more frequent in women drinking during pregnancy in both smokers and non-smokers (for this latter group an effect is suggested only for a daily consumption of more than 10 grams of absolute alcohol). Maternal alcohol drinking of more than 20 grams of absolute alcohol per day also increased the risk of preterm delivery (OR = 2.35; 95% CI: .98-5.59). Finally, an increase in the rate of early jaundice was found, also associated with maternal drinking (OR = 3.30; 95% CI: 1.03-10.54).

[The pediatric emergency department: assessment of clinical activity and interaction with local health authorities]. / Il pronto soccorso pediatrico: valutazione dell'attività e interazione con i servizi territoriali.

A perspective study was carried out at the Emergency Department of the Gaslini Institute on a sample of the children admitted from May to September 1990. The study aimed to describe types and modalities of admission. "G. Gaslini" Institute is a multidisciplinary children's hospital: 45% of patients admitted in the hospital come from the southern regions of Italy, while the admission at the Emergency Department were local in 82%. Among all children considered, 2080 (71.9% were admitted on request of their parents, who did not ask previously any physician; of those cases, 356 (17%) were hospitalized, 474 (25%) were either examined by specialist or treated and then discharged. In the remaining cases, no intervention was necessary. As a consequence, 58% of children were admitted without any clinically plausible reason. Parents' anxiety clearly played an important role in most cases. 840 children were addressed to the Emergency Department by a physician, 652 (22.3%) by the doctor in charge, 213 (32.7%) of which were sent back home by the doctor on duty, who did not think it necessary any treatment. Of the 120 (4.1%) children sent by different Emergency Departments, 95 (79.1%) were hospitalized. The reason why physicians addressed quite a large number of children to the Emergency Department, when they didn't need any intervention remain nucleo. Their diagnosis, in fact, agreed with those of the doctor on duty in 83% of cases. In conclusion, it is difficult to imagine a diagnostic or therapeutic problem which needs specific structures. Cooperative programs with physicians working in our region will be carried out in order to control, where possible, admission to Emergency Departments.

Bilateral breast involvement in a 71-year-old white man with lambda light chain disease. Regression after a new chemotherapy combination. A case report.

A rare case of lambda light chain disease with bilateral breast involvement is described. A complete regression after a new chemotherapy combination (peptichemio + teniposide + dexamethasone) was obtained. A previous treatment with prednisone + melphalan was ineffective.

[Cerebral arteriovenous malformations (CAVM)]. / Le malformazioni artero-venose endocerebrali (MAV).

Two infants with endocranic A-V malformations and irreversible picture of congestive cardiac failure are presented: the first is a newborn with a very large angioma, the second is a newborn with a large aneurysm of the vein of Galen. A review of the literature is presented: the salient age-related features required to make a diagnosis are discussed.

Effect of passive smoking during pregnancy on selected perinatal parameters.

A prospective study of 1004 consecutive deliveries was carried out to investigate the effect of passive smoking during pregnancy on a set of perinatal parameters. The data set was a cooperative study involving 11 Italian cities, distributed nationally. The study group was divided in three categories according to the mother's cigarette smoke exposure during pregnancy, ie, not smokers, passive smokers, direct smokers. Potential confounders, including paternal characteristics, were adjusted for by multiple linear regression analysis. A mean reduction of 16 g (p less than 0.07) in birthweight and a decrease in birth length of 0.05 cm (p less than 0.08) were found for each hour of antenatal passive smoke exposure. No or slight effects were reported for the other perinatal parameters considered.

Control de la infección hospitalaria en un servicio de terapia intensiva / Nosocomial infection control in an Intensive Care

El presente trabajo prospectivo ha tenido como objetivo la disminución de la incidencia de infección intrahospitalaria en un área de Terapia Intensiva de la M.C.B.A., a través del estudio de la cadena epidemiológica, la identificación de los factores de riesgo, la elaboración de normas de control y la formación de recursos humanos. Se efectuó el seguimiento longitudinal durante ocho meses y posteriormente en forma inmediata se pasó a desarrollar el programa de Control de Infecciones. Los resultados obtenidos a los ocho meses de aplicación han sido altamente satisfactorios y nos impulsaron a darlos a conocer, aunque para una programación de éste tipo la evaluación pueda ser considerada prematura

Control de la infección hospitalaria en un servicio de terapia intensiva / Nosocomial infection control in an Intensive Care

El presente trabajo prospectivo ha tenido como objetivo la disminución de la incidencia de infección intrahospitalaria en un área de Terapia Intensiva de la M.C.B.A., a través del estudio de la cadena epidemiológica, la identificación de los factores de riesgo, la elaboración de normas de control y la formación de recursos humanos. Se efectuó el seguimiento longitudinal durante ocho meses y posteriormente en forma inmediata se pasó a desarrollar el programa de Control de Infecciones. Los resultados obtenidos a los ocho meses de aplicación han sido altamente satisfactorios y nos impulsaron a darlos a conocer, aunque para una programación de éste tipo la evaluación pueda ser considerada prematura (AU)

[5-Fluorouracil in the treatment of acute pancreatitis. Our experience]. / Il 5-fluorouracile nel trattamento della pancreatite acuta. Nostra esperienza.

A report is presented on 24 cases of acute pancreatitis treated with infusion of 5-fluorouracil. Though the action mechanism of the drug is still uncertain, fairly satisfactory results were obtained in terms of both clinical symptoms and laboratory findings, while the effect of the drug on the pain symptom could even be called spectacular. It is therefore considered that the treatment of acute pancreatitis with 5FU deserves serious consideration.

[Hypothalamo-hypophyseal metastasis: a rare initial manifestation of adenocarcinoma of the jejunum. Description of a clinical case]. / Metastasi ipotalamo-ipofisaria: rara manifestazione iniziale di adenocarcinoma del digiuno. Descrizione di un caso clinico.

A rare case of jejunal adenocarcinoma is described in which the initial clinical sign was diabetes insipidus and hypopituitarism linked to hypothalamohypophyseal metastasis. The rarity of the intestinal neoplasm and the unusual site of the metastatic lesions are underlined.