Self-amplified spontaneous emission free-electron laser with an energy-chirped electron beam and undulator tapering

We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a self-amplified spontaneous emission mode free-electron laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. An increase of more than 1 order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.

[Cardio-renal syndrome: the challenge in heart failure treatment]

Heart failure is a chronic and progressive disease that is estimated to affect approximately 20 million people worldwide and is one of the major public health problems. Its prevalence is reaching epidemic levels with about 550,000 new cases diagnosed annually, partly due to increased life expectancy in developed countries. And as it is a systemic disease, it can cause dysfunction in various organs, but especially in the kidney. The renal failure is often associated with heart failure and, when present together, make the treatment more complex and the prognosis is worse. This is the cardio-renal syndrome. The definition of cardio-renal syndrome varies according to the working groups, and there isn't a consensus. The exact cause of deterioration of renal function and the mechanism behind this interaction are complex, multifactorial in nature and not fully known at present. The treatment available is the one used for the treatment of heart failure. It is necessary to maintain the normal function of filtration, secretion and reabsorption in kidney to have a real improvement of the clinical condition of the patient. Patients with higher risk of developing nephropathy and those who have diagnosed renal failure should have prescribed drugs that are handled very carefully. But as in many other clinical situations, there aren't perfect drugs available to treat cardio-renal syndrome and the existing ones may have serious side effects in medium/long term causing the deterioration of renal function and possibly an increased mortality. The treatment is truly challenging in patients with severe fluid overload that is refractory to diuretics. This article aims to present the existing definitions of cardio-renal syndrome, its epidemiology, describe the current knowledge about the pathophysiology and its relationship to therapeutic interventions, some actual strategies and future technologies in an attempt to preserve the kidney, mainly during the decompensation of chronic heart failure.

Seasonal and spatial variability of water quality parameters in the Port of Genoa, Italy, from 2000 to 2007

This paper presents the results of the statistical analysis of a set of physico-chemical and biological water quality parameters, monthly collected from 2000 to 2007 in the Genoa Harbour area (Ligurian Sea). We applied multivariate methods, such as principal component analysis (PCA) and dynamic factor analysis (DFA) for investigating the spatial and temporal variability and for providing important background information on pollution problems in the region. PCA evidenced the role of the sewage and river discharges and of the exchanges with the open sea in determining the harbour water quality. DFA was used to estimate underlying common trends in the time series. The DFA results partly show a general improvement of water quality over the 8-years period. However, in other areas, we found inter-annual variations but no significant multi-annual trend. Furthermore, we included meteorological variables in our statistical analyses because of their potential influence on the water quality parameters. These natural forcings explain part of the variability in water quality parameters that are superimposed on the dominating anthropogenic pollution factors.

Prevalence of double pituitary adenomas in a surgical series: Clinical, histological and genetic features

BACKGROUND

The term double pituitary adenomas (DPA) is usually referred to those rare lesions showing two distinct cellular components. Genetic background may sustain the proliferation of more than one cell at the same time but no information is available on the presence of aip mutations in these patients.

AIM

We report the prevalence and the endocrinological, neuroradiological, histopathological and genetic features of DPA detected in a large surgical series. The contribution of pituitary transcription factor immunostains in DPA was also evaluated.

SUBJECTS AND METHODS

One-hundred-forty-four patients undergoing surgery for tumors of the sellar region were evaluated. Histopathology, immunohistochemistry and the mutational analysis for the entire coding region of the AIP and MEN1 genes were performed.

RESULTS

One-hundred-seventeen patients out of 144 had a pituitary adenoma. DPA was found in 3 (2.6%) out of 117 patients with pituitary adenoma. Immunohistochemistry and transcription factors analysis demonstrated two not yet described histotype associations in DPA. The coexistence of somatotroph-lactotroph and silent mammosomatotroph histotype in 1 case and the coexistence of sparsely granulated lactotroph and null cell adenomas in the remaining two cases were first identified. Sequencing data for the coding region of the aip and the menin gene resulted in wild type sequences in all patients with DPA.

CONCLUSIONS

The prevalence of DPA observed in our unselected surgical series is not negligible (2.6%). Furthermore, the evaluation of the treatment outcome would suggest that the clinical management of DPAs requires a careful diagnostic approach and follow- up.

Experimental demonstration of emittance compensation with velocity bunching

In this Letter we report the first experiments aimed at the simultaneous demonstration of the emittance compensation process and velocity bunching in a high brightness electron source, the SPARC photoinjector in INFN-LNF. While a maximum compression ratio up to a factor 14 has been observed, in a particular case of interest a compression factor of 3, yielding a slice current of 120 A with less than 2 microm slice emittance, has been measured. This technique may be crucial in achieving high brightness beams in photoinjectors aiming at optimized performance of short wavelength single-pass free electron lasers or other advanced applications in laser-plasma accelerators.

Prevalence of parathyroid cysts by neck ultrasound scan in unselected patients

BACKGROUND

Parathyroid cysts (PC) are a rare entity, representing only 0.5-1% of all parathyroid lesions and <1% of neck masses. Since its first description, in the second half of the 19th century, fewer than 300 cases have been reported. By reviewing the literature, it appears that the data available arose from surgical series, and the precise incidence of PC as detected by ultrasound (US) has not been described. The aim of this study was to review 5 yr of routine neck US, mainly performed for thyroid diseases, in order to estimate the prevalence of PC in a large series of patients.

METHODS

We reviewed our database of neck US investigations performed from 2003 to 2007: all data regarding patient's clinical history, US images, and fine needle aspiration cytology were retrospectively collected.

RESULTS

Among 6621 patients submitted to neck US investigation, a PC (mean diameter 36.4+/-14.2 mm; range 25-61 mm) was diagnosed in 5 cases. Serum PTH levels were high in all the patients (221+/-140.7 pg/ml; range 111-456 pg/ml), whereas serum calcium levels only in 3 subjects (10.8+/-1.4 mg/dl; range 9.2-12.9 mg/ml).

CONCLUSION

This is the first study evaluating the prevalence of PC in a large series of unselected patients by US. Our results demonstrate a much lower incidence (0.075%) of incidentally detected PC than previously reported.

Selection of variables for on-line monitoring, diagnosis, and control of anaerobic digestion processes

This work aims to systematize the study of indicators for two types of wastewaters: carbohydrate-based and protein-based synthetic wastewaters. Characterization of steady states and dynamic response analysis against disturbances were carried out using both a factorial discriminant analysis (FDA) and a phenomenological analysis, respectively. This research seeks reconciling both sets of indicators in order to optimize resources and provide a minimal cost in instrumentation for its implementation at industrial scale. According to the results of this research, the best indicators for the two types of wastewaters, considering both process steady states and organic load perturbations are: Biogas flow rate or Methane flow rate, and Hydrogen concentration in the biogas; Volatile fatty acids and Partial alkalinity in the liquid phase.

Modified percutaneous ethanol injection of parathyroid adenoma in primary hyperparathyroidism

Surgery is the treatment of choice for symptomatic primary hyperparathyroidism; unlikely few patients do not meet established surgical criteria or have comorbid conditions that prohibit surgery. In these subjects, medical therapy alone offers little hope for a sustained long normocalcemic period. However percutaneous ethanol injection (PEI) may represent an alternative therapeutic procedure. It is currently in use for the treatment of secondary or tertiary hyperparathyroidism, however, few studies or case reports suggest it for the treatment of primary hyperparathyroidism. Moreover, little information is available about the long-term follow-up, where incomplete necrosis or the spreading of ethanol in the surrounding tissues is often reported. We believe that many of the side effects could be correlated to procedure itself. Taking these experiences into account, we have reasoned that in order to limit these side effects, we had to modify the standard PEI procedure. We reported this preliminary experience describing our modified PEI procedure.

The role of imaging in Graves’ disease: A cost-effectiveness analysis

According to many guidelines, scintigraphy remains the first suggested diagnostic procedure in hyperthyroid patients in spite of the widespread availability of ultrasounds. The aim of this study was to evaluate the cost-effectiveness of sonography versus scintigraphy in the management of Graves's disease, and to assess ultrasound features suggesting cancer in detecting thyroid nodules. Among 1470 hyperthyroid patients evaluated in our department from 2002 to 2005, 426 (29%) had Graves' disease: echographic and scintigraphic features were not suggestive of GD in 20/426 (4.8%) and 11/426 (2.6%) patients, respectively (p=0.763), even if one of the two procedures was almost always diagnostic. Ultrasound identified 68/426 (16%) patients with a concomitant solid lesion, while scintigraphy detected only 9/426 (2.1%) "cold" nodules (p<0.001). Thyroid cancer was diagnosed in 30/68 (47.7%) patients. Malignancy presented at ultrasound investigation blurred margins (26.7% versus 15.8%), microcalcifications (33.3% versus 28.9%) and an anteroposterior and transverse diameter ratio>or=1 (73.3% versus 71.1%); more frequently than benign nodules, but this was not statistically significant. The total cost to obtain a diagnosis by ultrasound was euro14645.34 (euro13312.5 for echography+euro1332.84 for scintigraphy in the 29 patients "negative" at echographic evaluation for GD) versus euro19922.71 by scintigraphy (euro19578.96 for scan+euro343.75 for ultrasounds in the 11 patients "negative" at scintigraphy). Our data show no difference in terms of diagnosis between sonography and scintigraphy. Indeed, scintigraphy was less sensitive in detecting nodules (often of malignant nature) than ultrasound, and, moreover, with a consequent increase of the direct cost of nodule management when scintigraphy is the first line procedure. In conclusion, according to our results, we suggest that ultrasounds with color-Doppler evaluation should be performed as first step in all hyperthyroid patients, and that scintigraphic examination should be limited only to the uncommon cases, where physician's observation, laboratory assays and/or ultrasounds are not diagnostic.

Spinal needle improves diagnostic cytological specimens of thyroid nodules

Ultrasound fine needle aspiration cytology (US-FNAC) represents the most effective test available to distinguish between benign and malignant thyroid nodules, with an accuracy approaching 95%. The major limit of this procedure it is the rate of inadequate specimens which is reported to be from 10% to 31%. Also because cost considerations have always been important and have recently become even more relevant for clinical guidelines in many countries, it is desirable to limit the number of inadequate samples. Recently, we have shown that the use of stylet needles greatly reduces inadequate cytological specimens in thyroid nodules with an intranodular vascular pattern. With the aim to improve our previous results, we have extended our procedure to all thyroid solid nodules. Between February 2004 and March 2006, 312 consecutive patients with thyroid nodule without intranodular vascular pattern at color-Doppler evaluation were enrolled in this prospective study. US-FNAC was performed by two different 25 gauge needles (Neolus [Ns] and Yale Spinal [YS]), and the two procedures were performed in alternate sequence on consecutive patients. Adequate specimens were observed in 145 (92.9%) and 153 (98%) nodules respectively investigated by Ns and in YS (p<0.005). The total cost to obtain a cytological diagnosis by Ns was of euro 12210.2 (156+12 repeated US-FNAC), whereas it was of euro 12449.7 by YS (156+3 repeated US-FNAC). Our data suggest that spinal needles are associated with a low proportion of inadequate FNAC, without increase of total direct cost, considering also the number of FNAC repetitions needed; therefore, their routine use could be taken into account.

Direct measurement of the double emittance minimum in the beam dynamics of the sparc high-brightness photoinjector

In this Letter we report the first experimental observation of the double emittance minimum effect in the beam dynamics of high-brightness electron beam generation by photoinjectors; this effect, as predicted by the theory, is crucial in achieving minimum emittance in photoinjectors aiming at producing electron beams for short wavelength single-pass free electron lasers. The experiment described in this Letter was performed at the SPARC photoinjector site, during the first stage of commissioning of the SPARC project. The experiment was made possible by a newly conceived device, called an emittance meter, which allows a detailed and unprecedented study of the emittance compensation process as the beam propagates along the beam pipe.

Fine needle cytology of complex thyroid nodules

OBJECTIVE

To evaluate whether a preliminary aspiration (ASP) of the cystic component and/or using spinal needles in complex thyroid nodules (CTN) could improve the adequacy of cytological sampling.

METHODS

Between January 2004 and December 2006, 386 consecutive patients with CTN were enrolled in this prospective investigation. Ultrasound (US) fine needle aspiration cytology (FNAC) of the solid component of the nodule (one nodule per patient) was performed using two different 25 gauge needles, with (Yale Spinal, YS) or without (Neolus, NS) a stylet, in alternate sequence on consecutive patients. In addition, a subgroup of patients presenting larger cystic component (approximately 50%) was submitted to total aspiration of the cystic component (ASP+) or not submitted (ASP-) before US-FNAC, in alternate sequence within each needle type group. All the samplings were performed by a single endocrinologist.

RESULTS

Adequate specimens were observed in 163 (84.5%) and 183 (94.8%) nodules investigated by NS and YS respectively. Sampling with the stylet needle was associated with an overall significant reduction of non-diagnostic specimens (15.5% vs 5.2% by NS and YS respectively, P < 0.001). The favourable result obtained with YS was independent from preliminary aspiration of the cystic component (ASP+: 14.8% vs 5.7% by NS and YS; ASP-: 16.2% vs 4.8%, not significant). A logistic regression analysis, taking into account nodule size and presence of intranodal vascularity at eco-colour evaluation of the solid component, confirmed that needle type was the only significant predictor of successful sampling (odds ratio 3.6 (95% confidence interval 1.7-7.6), P < 0.001).

CONCLUSIONS

Our data show that adopting stylet needles to perform FNAC in CTN may significantly improve the percentage of adequate sampling. On the other hand, preliminary aspiration of CTN with large cystic component does not add any advantage.

Selection of variables using factorial discriminant analysis for the state identification of an anaerobic UASB-UAF hybrid pilot plant, fed with winery effluents

Anaerobic wastewater treatment has become a widely used method for wastewater depuration, and has been applied in a wide range of situations, from urban wastewater to highly toxic industrial wastewater. Particularly it has been successfully applied to the treatment of the beverage industries effluents. To avoid the destabilization of the system a monitoring diagnosis and control system of the depuration processes is necessary. The cost of this system is an important issue, that depends on the number of parameters that must be controlled for an adequate performance of a wastewater plant control system. This work shows how the classic statistical classification techniques can be applied to determine the number variables that must be monitored to achieve an adequate performance of anaerobic UASB-UAF hybrid Pilot Plant monitoring and control system. The obtained results had not been unique, so different combinations of variables can be selected for a good wastewater treatment process control. Economic or technical criteria may be considered to determine the final variables set in each particular situation.

Aggressiveness and outcome of papillary thyroid carcinoma (PTC) versus microcarcinoma (PMC): A mono-institutional experience

BACKGROUND

Papillary thyroid carcinoma (PTC) represents 70%-75% of well-differentiated thyroid cancers. Although most reports have shown that papillary thyroid microcarcinomas (PMC) follow an indolent course, a few series have demonstrated that a significant number of them are associated with extrathyroidal extension and nodal or distant metastases.

METHODS

Four hundred eighty-four patients with papillary thyroid cancer (102, PMC; 382, PTC) were enrolled in this study. The median follow-up was 102 months.

RESULTS

No difference between PTC and PMC patients was observed for age, gender, multifocality, extrathyroidal extension, and lymph nodes metastasis. The prevalence of nodal involvement developing during the follow-up period was significantly higher in PMC than PTC (58.8% vs. 38.5%, P = 0.002). An unfavorable clinical course occurred in 96 subjects (21.8%). Logistic analysis showed that the strongest association with the worst prognosis was found for age and TNM stage III (P < 0.001). Analysis also confirmed that the presence of intranodular vascularity is a predictor of unfavorable outcome (P = 0.044).

CONCLUSIONS

We suggest always performing a total thyroidectomy followed by radiometabolic therapy in papillary carcinomas independent of their size. If the choice in PMCs should be more conservative (hemithyroidectomy), we purpose to limit this procedure to the cancers without Doppler features suggesting intranodular vascular pattern.

The predictive value of ultrasound findings in the management of thyroid nodules

BACKGROUND

Thyroid nodules are a common medical problem, but whether fine-needle aspiration cytology (FNAC) is mandated for smaller non-palpable nodules, is controversial.

AIM

To evaluate whether ultrasonographic features of thyroid nodules are associated with histological malignancy, and to identify useful criteria for clinical decision-making.

DESIGN

Prospective observational study.

METHODS

From January 1991 to September 2004, 5198 patients were referred to our hospital for ultrasound evaluation of thyroid nodules. Overall, 7455 nodules (diameters from 6 to 100 mm) were examined; 2865 (38.4%) were <10 mm in diameter. All patients with suspicious or malignant cytology underwent surgery.

RESULTS

Of the 349 nodules undergoing surgery, 284 were malignant. The prevalence of cancer was slightly higher in nodules>or=10 mm in diameter vs. those<10 mm (5.5% vs. 3.0%, p<0.01). However, histological type and local aggressiveness were largely independent of nodule size. Microcalcifications (72.2% vs. 28.7%; p<0.001; OR 6.4, 95%CI 4.9-8.4), blurred margins (52.8% vs. 18.8%; p<0.001; OR 4.8, 95%CI 3.8-6.1), solid hypoechoic appearance (80.6% vs. 52.4%; p<0.001; OR 3.8, 95%CI 2.8-5.1), size>or=10 mm (77.4% vs. 64.9%; p<0.001; OR 1.9, 95%CI 1.4-2.5) and intranodular vascular pattern type 2 (61.6% vs. 49.7%; p<0.001; OR 1.6, 95%CI 1.2-2.0) were all significantly more frequent in malignant than in benign nodules. These associations were similar when large and small nodules were analysed separately.

DISCUSSION

No single parameter, including nodule size, satisfactorily identifies a subset of patients to be electively investigated by FNAC, although several may be useful in this regard.

Genetic mutation screening in an italian cohort of nonsyndromic pheochromocytoma/paraganglioma patients

To assess the prevalence of genetic mutations in nonsyndromic pheochromocytoma/paraganglioma (PHEO/PGL) patients we have performed a systematic search for mutations in the succinate dehydrogenase (SDH) B, C, and D subunits, von Hippel-Lindau (VHL), and RET genes by direct bidirectional sequencing. Patients were selected from the medical records of hypertension centers. After exclusion of syndromic patients, 45 patients with familial (F+, n=3) and sporadic (F-, n=42) cases of isolated PHEO/PGL were considered. They included 35 patients with PHEO, 7 with PGL, and 3 with head/neck PGL (hnPGL). Three patients with PHEO (2F-, 1F+) presented VHL mutations (P86A, G93C, and R167W), six with PGL (4F-, 2F+) were positive for SDH or VHL mutations (SDHB R230G in two patients, SDHB S8F, R46Q, R90Q, and VHL P81L in one subject each), and one with hnPGL carried the SDHD 348-351delGACT mutation. We have also detected missense (SDHB S163P, SDHD H50R and G12S), synonymous (SDHB A6A, SDHD S68S), and intronic mutations that have been considered nonpathological polymorphic variants. No mutation was found in SDHC or RET genes. Our data indicate that germline mutations of VHL and SDH subunits are not infrequent in familial as well as in sporadic cases of nonsyndromic PHEO/PGL (overall, 12 of 45 probands, 22%). Accordingly, screening for such mutations seems to be justified. However, a more precise characterization of the functional relevance of any observed sequence variant and of other genetic and environmental determinants of neoplastic transformation is essential in order to plan appropriate protocols for family screening and follow-up.

A completely automated CAD system for mass detection in a large mammographic database

Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing second-order spatial statistics information on the pixel gray level intensity. As the images under study were recorded in different centers and with different machine settings, eight GTSDM features were selected so as to be invariant under monotonic transformation. In this way, the images do not need to be normalized, as the adopted features depend on the texture only, rather than on the gray tone levels, too. (c) ROI classification by means of a neural network, with supervision provided by the radiologist's diagnosis. The CAD system was evaluated on a large database of 3369 mammographic images [2307 negative, 1062 pathological (or positive), containing at least one confirmed mass, as diagnosed by an expert radiologist]. To assess the performance of the system, receiver operating characteristic (ROC) and free-response ROC analysis were employed. The area under the ROC curve was found to be Az = 0.783 +/- 0.008 for the ROI-based classification. When evaluating the accuracy of the CAD against the radiologist-drawn boundaries, 4.23 false positives per image are found at 80% of mass sensitivity.

Ectopic lingual thyroid tissue and acquired hypothyroidism: case report

Ectopic thyroid tissue with thyroid gland in its normal location is an extremely rare phenomenon. We present a case of a 38-year-old woman who was referred to our hospital with symptoms of hypothyroidism. Thyroid hormone measurement revealed clinical hypothyroidism with elevated anti-thyroid antibodies, neck ultrasonography showed a small tissue with the characteristic of Hashimoto thyroiditis, while the scintigraphy demonstrated only a lingual thyroid. Treatment consisted in L-thyroxine replacement to the euthyroid state. We reviewed the literature with respect to the embryological background and the clinical management of such cases.

Cost-effectiveness of fine-needle-aspiration cytology of thyroid nodules with intranodular vascular pattern using two different needle types

OBJECTIVE

To compare the cytological findings of hypoechoic thyroid nodules with intranodular vascular pattern (pattern II) obtained by two different needles (Neolus 25 gauge, Chemil, Wenzhou, China vs Yale Spinal 25 gauge, Becton Dickinson, Madrid, Spain) in euthyroid patients and to evaluate their cost-effectiveness.

METHODS

From January 2001 to December 2003, 480 euthyroid patients with a hypoechoic thyroid nodule pattern II were referred for US-FNAC. The nodules were alternatively evaluated by Neolus or by Yale Spinal with the stylet (YS+) or without the stylet (YS-), in order to evaluate if the cytological results could be due to the presence of the stylet or to the different length of the two needles. For each nodule two passes were performed and the material was obtained by capillary action. Material was smeared on slides, fixed, and stained by Papanicolaou techniques. Cytological specimens were evaluated in blind by the same experienced cytopathologist.

RESULTS

Inadequate cytological specimens because of blood contamination were present in 30 (18.7%) samples by Neolus needle and in 22 (13.8%) by YS- compared to only 5 (3.1%) by YS+. In 6 (20%) cases of the 30 repeated US-FNAC by Neolus and in 4 (18%) of the 22 US-FNAC by YS-, material remained inadequate for diagnosis because of blood contamination. All the five repeated samples obtained by YS+ became adequate for diagnosis and resulted benign nodules. Direct costs of US-FNAC procedure are currently 72.30 Euro including cytological examination. The cost of Neolus and Yale needles is 0.19 Euro and 3.0 Euro, respectively. The estimated total cost to obtain a cytological diagnosis by a Neolus needle (160 + 30 repeated US-FNAC) was 13809.2 Euro vs 12919.5 Euro by Yale Spinal needle (160 + 5 repeated US-FNAC).

CONCLUSION

This study demonstrates that the use of Yale Spinal needles greatly reduces inadequate cytological specimens, and therefore limits both direct and indirect costs.

Treatment of severe chronic venous insufficiency using the subfascial endoscopic perforator vein procedure

BACKGROUND

Before 1985, corrective surgical procedures for patients with chronic venous insufficiency and venous ulcers were performed using long incisions through diseased skin and subcutaneous tissues. The procedure, involving ligation of incompetent perforator veins, known as "the Linton operation," often was complicated by wound infections and poor healing. This changed in 1985 when G. Hauer demonstrated a new surgical technique for direct visual identification of the incompetent perforator veins using an endoscope in the subfascial space. This seminal contribution marked the advent of subfascial endoscopic perforator vein surgery (SEPS).

METHODS

From 1996 to 2004, the authors group prospectively collected data on 110 patients with chronic venous insufficiency who underwent a SEPS procedure. Preoperative assessment of the limb's vascular status consisted of color-flow duplex ultrasound imaging and ascending and descending phlebography to locate vein valve incompetence, along with venous mapping. The ages of the patients ranged from 42 to 82 years (mean, 60 years). A total of 128 limbs underwent the SEPS procedure in the cohort of 110 patients. According to CEAP classification for venous limb disease, 60 limbs belonged to group C5 (skin changes, pigmentation, venous eczema, lipodermatosclerosis, healed ulcer) and 68limbs to group C6 (skin changes and active ulceration).

RESULTS

The 110 patients underwent 128 SEPS procedures without significant morbidity. Of the 68 limbs in class C6, 54 showed ulcer healing within the follow-up period of 12 weeks. The remaining 14 limbs in class C6 achieved ulcer healing within 24 weeks. In this latter group, 10 patients had venous ulcers larger than 4 cm in diameter. These patients underwent a split-thickness skin graft at the time the SEPS procedure was performed. The grafts remained healed during a 2-year follow-up period.

CONCLUSIONS

This study demonstrated the effectiveness of the SEPS procedure when incorporated into the overall treatment strategy for patients with chronic venous insufficiency. Minimal postoperative complications accompanied by ulcer healing and relief of lower extremity symptoms were achieved for all the patients, underscoring the important role of incompetent perforator veins in the formation of chronic venous insufficiency.

Modification of cellulose fibres with organosilanes: Under what conditions does coupling occur?

Different cellulose substrates and organosolv lignin were treated heterogeneously with organic solutions of trialkoxysilanes bearing variable function on the forth substituent. It was shown unambiguously for the first time that Si-OR does not react with the hydroxy groups of cellulose even at high temperature, whereas it condenses with the phenolic OH of lignin. The addition of moisture to these systems induces the partial hydrolysis of the siloxane moieties and the ensuing silanol groups can then react with the cellulose OH, but only at high temperature. Using the latter systems and a siloxane bearing a polymerizable function, it was possible to attach poly(methylmethacrylate) chains to the surface of cellulose fibres through a two-step procedure.

A Morphometric Investigation by TEM/AIA on Elastomer-Based Compounds Filled with an Untreated Precipitated Silica

An accurate morphological investigation has been carried out on vulcanized compounds based on different matrices, butadiene rubber, natural rubber and styrene-butadiene rubber, filled with 35phr of a precipitated silica. The analysis has been performed by using transmission electron microscopy (TEM) and automated image analysis (AIA) to achieve quantitative information on the filler dispersion. Significant differences in the aggregate size and shape distribution of silica within the different matrices which, in principle, can be related to the polymer-filler interactions, have been found. The results are in a very satisfactory agreement with thermodynamic predictions obtained by inverse gas chromatography. The use of two complementary techniques, TEM/AIA, allows attainment, in a reasonably short time, quantitative information on the filler dispersion and, consequently, on the performances of these elastomers-based composite materials.

Circulating adhesion molecules and carotid artery structural changes in patients with noninsulin-dependent diabetes mellitus

Hypertension and non insulin-dependent diabetes mellitus (NIDDM) are well-known risk factors for atherosclerotic disease. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may exert a relevant role in the pathogenesis of atherosclerosis; their prognostic relevance has been recently demonstrated. The aim of the study was to investigate possible inter-relation between circulating adhesion molecule levels, carotid artery structure and endothelial function in 15 patients with NIDDM, as well as in 15 patients with both NIDDM and essential hypertension (NIDDM+EH) compared with 15 normal subjects (NS) and 15 euglycaemic patients with EH, matched for age, sex and body weight. All subjects were submitted to a biopsy of the gluteal subcutaneous fat. Small arteries were dissected and mounted on a micromyograph, and the media-to-lumen (M/L) ratio was then calculated. Carotid artery structure was investigated by Doppler ultrasound. Endothelial function was evaluated by investigation of the flow-mediated dilatation (FMD) of the brachial artery. ICAM-1 and VCAM-1 plasma levels were measured by ELISA. ICAM-1 and VCAM-1 plasma levels were significantly greater and FMD smaller in EH, NIDDM and NIDDM+EH than in NS, but no difference was observed among the three pathological groups. Carotid artery structural changes were more pronounced in NIDDM+EH. No significant difference was observed among NIDDM, EH and NS. The M/L ratio of subcutaneous small resistance arteries was significantly greater in NIDDM+EH than in NIDDM or EH. NS had a smaller M/L ratio than the other groups. Significant correlations were observed between ICAM-1 plasma levels and indices of carotid artery structure in diabetic patients. However, the relations were close only in NIDDM+EH. In conclusion, our data suggest that NIDDM+EH may present more pronounced vascular structural alterations than NIDDM, and that adhesion molecules plasma levels are closely inter-related with carotid artery structural alterations, at least in NIDDM+EH, but not with M/L ratio of small resistance arteries.

Search for the prewave zone effect in transition radiation

Results of the first experimental search for the effect of the prewave zone in near-infrared transition radiation are presented. A substantial difference in the spatial distribution of transition relation for two different wavelengths (450 nm and 1600 nm) was observed. Experimental data are in a good, though not complete, agreement with the theory.

Loss of p16 expression is associated with histological features of melanoma invasion

While mutations of CDKN2A are associated with melanoma predisposition, the precise role of its gene product p16 in the development of sporadic melanoma is less clearly understood. We sought to determine the prevalence of p16 expression using immunohistochemical analysis in a population-based sample of melanoma tumours, and also to identify histological, phenotypic and environmental factors associated with the presence or absence of p16 expression. We conducted face-to-face interviews with 108 patients newly diagnosed with melanoma to ascertain their history of sun exposure, and recorded various phenotypic parameters. Paraffin sections of tumours from these patients were stained with an anti-p16 monoclonal antibody following antigen retrieval. Overall, 52 (48%) tumours expressed p16; nodular melanomas had significantly lower levels of p16 immunoreactivity than superficial spreading melanomas (P = 0.015). While no association was found between p16 expression and host phenotype, loss of p16 staining was associated with thicker lesions (p = 0.084) and a high mitotic index (P = 0.013). Taken together, these findings are consistent with loss of p16 being a late event in the progression of sporadic primary melanomas, being associated with tumours of a more aggressive nature.

Generation of GW radiation pulses from a VUV free-electron laser operating in the femtosecond regime

Experimental results are presented from vacuum-ultraviolet free-electron laser (FEL) operating in the self-amplified spontaneous emission (SASE) mode. The generation of ultrashort radiation pulses became possible due to specific tailoring of the bunch charge distribution. A complete characterization of the linear and nonlinear modes of the SASE FEL operation was performed. At saturation the FEL produces ultrashort pulses (30-100 fs FWHM) with a peak radiation power in the GW level and with full transverse coherence. The wavelength was tuned in the range of 95-105 nm.

Contrasting effects of verapamil and amlodipine on cardiovascular stress responses in hypertension

AIMS

To compare the effects of two long-acting calcium antagonists of different types on cardiovascular stress responses in hypertension.

METHODS

One-hundred and forty-five patients with mild to moderate hypertension and a mean (+/- s.e.mean) age of 51 +/- 0.9 years received for 8 weeks the phenylalkylamine verapamil sustained release (240 mg) and the dihydropyridine amlodipine (5 mg) in a double-blind cross-over design, both after 4 weeks of placebo. Blood pressure, heart rate and plasma noradrenaline were monitored during 3 min of sustained isometric handgrip and 2 min of cold pressor.

RESULTS

Blood pressure was equally reduced by both drugs. After 3 min handgrip, systolic blood pressure, heart rate and rate-pressure product were lower with verapamil compared with amlodipine. Verapamil attenuated the increases in systolic blood pressure (25 +/- 2 vs 30 +/- 2 mmHg, difference 4.6, 95% CI (1.0, 8.1), P < 0.01) and rate-pressure product (3.1 +/- 0.2 vs 3.6 +/- 0.3 x 10(3) mmHg x beats min(-1), difference 0.5, 95% CI (0.1, 0.9), P < 0.01) during handgrip compared with amlodipine. Similar results were observed during cold pressor. Plasma noradrenaline levels were lower with verapamil compared with amlodipine at rest and after both tests, but the increases in plasma noradrenaline were not significantly different.

CONCLUSIONS

Verapamil is more effective in reducing blood pressure and rate-pressure product responses to stress compared with amlodipine. Although plasma noradrenaline is lower with verapamil at rest and after stress, the increase during stress is not different.

The effects of dihydropyridine and phenylalkylamine calcium antagonist classes on autonomic function in hypertension: the VAMPHYRE study

The aim of the present study was to compare the effects of a long-acting dihydropyridine (amlodipine) and a nondihydropyridine (verapamil) on autonomic function in patients with mild to moderate hypertension. A total of 145 patients with a diastolic blood pressure (BP) between 95 and 110 mm Hg received 8 weeks of verapamil sustained release (240 mg) and amlodipine (5 mg) in a prospective randomized, double blind, cross-over study, both after 4 weeks of placebo. The 24-h autonomic balance was measured by analysis of 24-h heart rate variability and short-term autonomic control of BP by baroreflex sensitivity measurements. Plasma norepinephrine was sampled at rest. Blood pressure was equally reduced from 153/100 mm Hg to 139/91 mm Hg with verapamil and 138/91 mm Hg with amlodipine, P = .50/.59. The low- to high-frequency ratio (LF/HF), reflecting sympathovagal balance, was higher with amlodipine than with verapamil (4.66 v 4.10; P = .001). Baroreflex function was improved by both treatments; however, baroreflex sensitivity (BRS) was significantly higher with verapamil than with amlodipine (8.47 v 8.06 msec/mm Hg; P = .01). Plasma norepinephrine (NE) level was higher with amlodipine than with verapamil (1.59 v 1.32 nmol/L; P < .0001). Amlodipine induces a shift in sympathovagal balance, as measured by heart rate variability indices and plasma NE, toward sympathetic predominance compared with vagal predominance with verapamil. Short-term autonomic control of BP, as assessed by BRS, is more effectively improved by verapamil than by amlodipine. These contrasting effects on autonomic function suggest that the nondihydropyridine calcium antagonist verapamil may have additional beneficial effects beyond lowering BP compared with the dihydropyridine amlodipine.

[Heroin prescribing: Is there scientific evidence of its efficacy for the treatment of its dependence?]

It is in the United Kingdom where medical prescription of opiates has been more widely used. Although these practice had been increasing until the sixties, several factors caused a decreased since then, so that it is currently 1.6% of all maintenance programmes, becoming methadone prescription more important. Mainly through studies conducted in Switzerland, the debate over the appropriateness of this practice. In such studies, it appears that heroin prescription supports important improvements in the patients outcome, as it is associated with better retention rates, a reduction in abuse of illicit substances, and improvements in patients health and social aspects. However, methodological limitations of these studies and ambiguous results of studies carried out in other countries, make it difficult to determine the effectiveness or efficacy of this pharmacotherapy, so that more studies are needed to scientifically justify this practice.

Measurements of coherent diffraction radiation and its application for bunch length diagnostics in particle accelerators

Measurements of coherent diffraction radiation from a slit of variable width generated by short electron bunches were performed in millimeter and submillimeter ranges. Experimental data are compared with the transition radiation case and theoretical predictions. A more realistic description than the conventional theory is necessary to account for the data correctly. No noticeable difference in the estimated bunch length was observed using diffraction radiation in a wide range of slit widths and transition radiation.

The smoothness index, but not the trough-to-peak ratio predicts changes in carotid artery wall thickness during antihypertensive treatment

BACKGROUND

It has recently been demonstrated that the smoothness index (SI) (the ratio between the average of the blood pressure changes computed for each hour of the recording and its standard deviation), a new and reproducible measure of the homogeneity of blood pressure reduction by antihypertensive treatment, has evident advantages over trough-to-peak ratio (T/P) in the prediction of the regression of left ventricular hypertrophy. Therefore we considered it to be worthwhile to compare the ability of SI and T/P to predict changes of the carotid artery intima-media thickness (IMT) during pharmacological treatment in patients with essential hypertension.

METHODS

In 100 patients with essential hypertension, 24 h ambulatory blood pressure and carotid artery IMT were measured after 3 weeks of therapeutic wash-out and after 12 months of antihypertensive treatment (calcium antagonists, diuretics, angiotensin converting enzyme (ACE) inhibitors or beta-blockers). The homogeneity of the effect of treatment over blood pressure was evaluated by computing T/P and SI.

RESULTS

Twenty-four hour blood pressure was significantly reduced by therapy, while, on average, a small but significant increase in indices of carotid artery wall thickness was observed. However, IMT was clearly reduced in patients with high SI. Statistically significant correlations were observed between changes in indices of carotid artery IMT during therapy and SI. No significant correlation was observed between indices of carotid artery morphology and T/P, basal 24 h blood pressure or changes in blood pressure during therapy.

CONCLUSIONS

SI, but not T/P is the predictor of changes in carotid artery wall thickness. The information provided by SI is independent from basal blood pressure values. For carotid artery morphology, the smoothness of blood pressure reduction is even more important than its absolute change.