Enhanced fluorescence emitted by microdroplets containing organic dye emulsions.

In this paper, laser beam resonant interaction with pendant microdroplets that are seeded with a laser dye (Rhodamine 6G (Rh6G)) water solution or oily Vitamin A emulsion with Rhodamine 6G solution in water is investigated through fluorescence spectra analysis. The excitation is made with the second harmonic generated beam emitted by a pulsed Nd:YAG laser system at 532 nm. The pendant microdroplets containing emulsion exhibit an enhanced fluorescence signal. This effect can be explained as being due to the scattering of light by the sub-micrometric drops of oily Vitamin A in emulsion and by the spherical geometry of the pendant droplet. The droplet acts as an optical resonator amplifying the fluorescence signal with the possibility of producing lasing effect. Here, we also investigate how Rhodamine 6G concentration, pumping laser beam energies and number of pumping laser pulses influence the fluorescence behavior. The results can be useful in optical imaging, since they can lead to the use of smaller quantities of fluorescent dyes to obtain results with the same quality.

Properties of polidocanol foam in view of its use in sclerotherapy.

Foam sclerotherapy is a widely used method to treat varicose veins disease. It is easy to use and apply, affordable, and has high efficiency that depends on foam stability upon injection. Since sclerotherapy is usually applied in a medical doctor's office, one of the most employed methods to generate foam is based on the Tessari technique which uses pumping cycles of liquid and air in-and-out of a double syringe system. Finally, the produced foam exits through a small orifice (∼2mm) at the output of a three-way valve. The present work shows results regarding the factors that may influence foam stability (liquid to air ratio, type of connector, syringe diameter, number of pumping cycles, etc.) of a commonly used sclerosing agent (polidocanol). Furthermore, an effort is made to evaluate the effect of adding different substances on the stability of polidocanol foams (0.5% w/w) by altering the surface tension or/and the bulk and interfacial rheological properties of the fluids. It is shown that adding small concentrations of nonionic surfactants can increase foam stability with just a very small variation of the mean bubbles size.

Rapid, laser-induced conversion of 20-hydroxyecdysone and its diacetonide -- experimental set-up of a system for photochemical transformation of bioactive substances.

BACKGROUND: Photochemical transformation of certain bioactive compounds for the purpose of obtaining derivatives with increased bioactivity is a prospective area of synthetic chemistry. Ecdysteroids, analogs of the insect molting hormone, which can also exert several beneficial effects in mammals including humans, contain an enone moiety in their B ring, and, as such, are good candidates for photochemical transformations. MATERIALS AND METHODS: 20-hydroxyecdysone (20E), the most common ecdysteroid in Nature, and the easily obtained derivative 20-hydroxyecdysone 2,3;20,22-diacetonide (20ED), at different concentrations, were exposed to a 266 nm laser beam at an energy level of 6.5 mJ for different periods of time and evaluated for fluorescence emission during the process of irradiation. The products of irradiation were scanned from 200 to 1500 nm and then subjected to one-dimensional and two-dimensional thin layer chromatography. RESULTS: During irradiation, progressive significant changes in the fluorescence emission spectra were noted for both compounds with time that were accompanied by changes in their UV-Vis spectra. Full conversion of both compounds was reached within 14 minutes, and both compounds yielded several major products and several minor ones representing a wide polarity range. CONCLUSION: The photo-transformation system described here was proven to be a useful and flexibly adjustable tool for the laser-catalyzed conversion of bioactive compounds. Due to the multi-drug resistance reversal activity of the less polar ecdysteroids, several new products are promising for being tested against various cancer cell lines. Fractionation, isolation and characterization of the irradiated products are currently in process.

Medico-legal implications of sleep apnoea syndrome: driving license regulations in Europe.

BACKGROUND: Sleep apnoea syndrome (SAS), one of the main medical causes of excessive daytime sleepiness, has been shown to be a risk factor for traffic accidents. Treating SAS results in a normalized rate of traffic accidents. As part of the COST Action B-26, we looked at driving license regulations, and especially at its medical aspects in the European region. METHODS: We obtained data from Transport Authorities in 25 countries (Austria, AT; Belgium, BE; Czech Republic, CZ; Denmark, DK; Estonia, EE; Finland, FI; France, FR; Germany, DE; Greece, GR; Hungary, HU; Ireland, IE; Italy, IT; Lithuania, LT; Luxembourg, LU; Malta, MT; Netherlands, NL; Norway, EC; Poland, PL; Portugal, PT; Slovakia, SK; Slovenia, SI; Spain, ES; Sweden, SE; Switzerland, CH; United Kingdom, UK). RESULTS: Driving license regulations date from 1997 onwards. Excessive daytime sleepiness is mentioned in nine, whereas sleep apnoea syndrome is mentioned in 10 countries. A patient with untreated sleep apnoea is always considered unfit to drive. To recover the driving capacity, seven countries rely on a physician's medical certificate based on symptom control and compliance with therapy, whereas in two countries it is up to the patient to decide (on his doctor's advice) to drive again. Only FR requires a normalized electroencephalography (EEG)-based Maintenance of Wakefulness Test for professional drivers. Rare conditions (e.g., narcolepsy) are considered a driving safety risk more frequently than sleep apnoea syndrome. CONCLUSION: Despite the available scientific evidence, most countries in Europe do not include sleep apnoea syndrome or excessive daytime sleepiness among the specific medical conditions to be considered when judging whether or not a person is fit to drive. A unified European Directive seems desirable.

Clinical relevance of transabdominal ultrasonography and magnetic resonance imaging in patients with inflammatory bowel disease of the terminal ileum and large bowel.

BACKGROUND: Ileocolonoscopy represents the diagnostic standard in the work-up of patients with inflammatory bowel diseases (IBD). Patients are often reluctant to be colonoscoped because of the invasiveness and pain sensation during colonoscopy. AIMS: To compare the usefulness oftransabdominal ultrasound (US) and magnetic resonance imaging (MRI) in assessing disease extension and activity in patients with IBD restricted to the terminal ileum and large bowel. PATIENTS AND METHODS: 61 patients with IBD [37 Crohn's disease (CD) and 24 ulcerative colitis (UC)] were prospectively studied. All patients underwent clinical and laboratory assessment, ileocolonoscopy, transabdominal sonography, and MRI within 5 days. Involved bowel segments were defined as those with bowel wall thickness >3 mm and increased Doppler signal on US or contrast enhancement of the bowel wall on MRI. To compare disease activity endoscopic, MRI and US findings were graded with newly developed scores. RESULTS: The segment-by-segment analysis revealed an overall accuracy of 89% for US and 73% for MRI in identifying active IBD. The accuracy was better in patients with UC than in patients with CD for both US and MRI. The endoscopic activity index (EAI) correlated stronger with the US activity index (r = 0.884) than with the MRI activity index (r = 0.344). The correlation of US and MRI activity indices with EAI was better in patients with UC compared with patients with CD. All three imaging methods showed a significant correlation with clinical disease activity in patients with UC but not in patients with CD. CONCLUSION: This study provides strong evidence that US should be considered as a first-choice method for follow-up of patients with IBD of the terminal ileum and large bowel.

Clinical aspects of photodynamic therapy--Romanian experience.

Photodynamic therapy is an emerging method for local destruction of tissue by generating toxic oxygen species using light absorbed by an administered or an endogenously generated photosensitiser. It is a promising treatment for patients with cancer. More recently it has found increasing use as a method of therapy for non-cancerous illnesses. Following administration of a photosensitiser occurs an accumulation or retention in areas of cancer and disease relative to adjacent normal tissue. The photosensitiser is inactive until irradiated by light, following which cellular destruction occurs. This explanation is a good reason for the scientific and clinical interest in photodynamic therapy.

Sustained virological response in hepatitis C virus type 1b infected patients is predicted by the number of mutations within the NS5A-ISDR: a meta-analysis focused on geographical differences.

BACKGROUND AND AIMS: There is growing evidence that the response of hepatitis C virus (HCV) genotype 1b infected patients towards interferon (IFN) therapy is influenced by the number of mutations within the carboxy terminal region of the NS5A gene, the interferon sensitivity determining region (ISDR). PATIENTS AND METHODS: In order to attain better insight into this correlation, a file comprising published data on ISDR strains from 1230 HCV genotype 1b infected patients, mainly from Japan and Europe, was constructed and analysed by logistic regression. Sustained virological response (SVR) was defined as negative HCV RNA six months after treatment. RESULTS: The distribution of wild-, intermediate-, and mutant-type ISDR sequences differed significantly between Japanese (n = 655) (44.1%, 37.6%, and 18.3%) and European patients (n = 525) (24.8%, 63.4%, and 11.8%; p<0.001). There was a significant positive correlation between the number of ISDR mutations and SVR rate, irrespective of geographical region. The likelihood of SVR with each additional mutation within the ISDR was considerably more pronounced in Japanese compared with European patients (odds ratios 1.82 v 1.39; p<0.001). Pretreatment viraemia of <6.6 log copies/ml and ISDR mutant-type infection was associated with an SVR rate of 97.1% in Japanese patients but only 52.5% in European patients. Pretreatment viraemia was a stronger predictor of SVR than ISDR mutation number in Japanese patients whereas in European patients both parameters had similar predictive power. CONCLUSION: These data support the concept that mutant-type ISDR strains may represent a subtype within genotype 1b with a more favourable response towards IFN therapy.

Randomized, controlled trial with IFN-alpha combined with ribavirin with and without amantadine sulphate in non-responders with chronic hepatitis C.

BACKGROUND/AIMS: Efficacy and safety of interferon-alpha (IFN-alpha)/ribavirin retreatment with or without amantadine sulphate were evaluated in non-responders with chronic hepatitis C. METHODS: Two hundred twenty five consecutive non-responders to previous antiviral treatment(s) with IFN-alpha alone or in combination with ribavirin or amantadine were treated with IFN-alpha 2b 5 MU daily for 4 weeks, 5 MU tiw for 20 weeks, followed by 3 MU tiw for additional 24 weeks combined with ribavirin 1000-1200 mg/d. One hundred fifteen of 225 patients were randomized to receive amantadine sulphate 100 mg bid for 48 weeks. Treatment was discontinued in patients with detectable serum hepatitis C virus (HCV)-RNA at treatment week 24. RESULTS: An overall sustained virologic response with undectable serum HCV-RNA levels was observed in 49/225 patients (22%). Patients infected with HCV-genotype non-1 (P<0.001), low viremia (P=0.011) and only one previous antiviral treatment (P=0.032) were more likely to respond to antiviral retreatment. There was a trend towards higher sustained virologic response rates in patients receiving triple retreatment compared with those treated with IFN-alpha/ribavirin alone (25 versus 18%, P=0.172). CONCLUSIONS: The addition of amantadine was well tolerated and led to an improvement of sustained virologic responses compared with retreatment with IFN-alpha/ribavirin alone, in particular in patients with low baseline viremia.

Spectroscopic characteristics of metalloporphyrins used in photodynamic therapy.

The photodynamic therapy (PDT) became more and more widely used in the treatment of different malignant tumors. For present studies, porphyrins and haematoporphyrin derivatives, in the conditions of N2 laser radiation, were chosen because their strong absorption along a large spectral range; this makes possible the excitation of their fluorescence at 337.1 nm, which is the wavelength of the N2 pulsed laser radiation. The photophysical and photochemical properties depend on the central metal and the peripheral substituents. Trying to find an optimal sensitizer to be used with N2 laser in photodynamic therapy (PDT), a spectroscopic study of these dyes was performed. The obtained data show that the UV radiation emitted by a N2 pulsed laser may be used for PDT application; among other dyes having interesting characteristics, Zn-TSPP and Zn-TNP in DMSO at 0.5% concentration seem to be more relevant.

Regional anaesthesia in vascular surgery: a multidisciplinary approach to accelerate recovery and postoperative discharge.

A multimodal, rehabilitative, fast discharge approach to abdominal aortic surgery is analyzed. The approach was developed in two phases during the years 1997-2000: in the first phase (1997) patients had thoracic epidural anesthesia plus TIVA and analgesia. They had improvement of the classical surrogate outcomes and analgesia: pain relief, nasogastric tube withdrawal, mobilization, ileus, hospital length of stay were significantly (p< 0,01) improved when compared to a historical, standard management group (1996: general anesthesia or lumbar epidural anesthesia plus general anesthesia with gas). In the second phase we started a more aggressive perioperative approach based on thoracic epidural anesthesia plus general anesthesia with gas and spontaneous breathing and postoperative epidural analgesia, left subcostal minilaparotomy incisions, aggressive postoperative nursing and pain relief on the ward. Preliminary results on 44 patients show no mortality, low postoperative morbility (cardiac complications 2,2%, peripheral embolization 2,2%, no pulmonary complications), no ICU stay and fast hospital discharge (median: 3,5 days, range: 2-8 days) without complications. We conclude that preliminary data support the safety and the need for further improvement of a multimodal, aggressive rehabilitative approach in abdominal vascular surgery.

Dynamic and thermodynamic effects of glycerol on bovine serum albumin in aqueous solution: a tryptophan phosphorescence study.

The phosphorescence decay of bovine serum albumin in water-glycerol solutions at room temperature is analysed by the maximum entropy method. While in pure water the decay was found to be quasi-monoexponential, in water-glycerol mixtures it is associated with more complex lifetime distributions. This is a direct proof for the existence of multiple protein conformers. It was also found that the increase of the glycerol concentration induces a continuous shift of the lifetime pattern to longer lifetimes. This effect is analysed in connection with the coupling between the solvent viscosity and the internal protein mobility.

Risk of asymptomatic and symptomatic gallstones in moderately obese women: a longitudinal follow-up study.

Obesity is a rather documented risk factor for the formation of gallstones (GS) in women. The magnitude of the increased risk and the rates of GS occurrence, however, have not been well quantified, except for two studies on the risk of symptomatic stones in obese women. We analyzed the incidence of GS in 157 moderately obese women (body mass index, 31.4 +/- 3.6 kg/ m2) followed up prospectively by ultrasound for 2-6 yr (mean 3.95 yr). Women with morbid obesity (body mass index > 40 kg/m2) were excluded from the study, as well as patients having diseases with lithogenic risk. All the enrolled women had normal cholecystosonogram results at the beginning of the study. Age, family history of GS or obesity, parity, age of obesity onset, hyperlipoproteinemia type, plasma cholesterol (total, HDL, LDL), and triglycerides were assessed. The Student's t, the Mann-Whitney rank sum and the Fisher's exact tests were used, as well as the multiple logistic regression for the multivariate analysis. During the survey, 16 of 157 women (10.2%) developed GS. GS were asymptomatic in 11 persons (68.8%). The cumulative incidence of both asymptomatic and symptomatic GS was 2.6 cases/100 obese women.year. During the follow-up, most of the detected GS were asymptomatic, and this explains the higher GS incidence rate found compared with that previously calculated for symptomatic GS. The following risk factors were associated with GS formation: age (p = 0.002), family history of GS (p = 0.011), early obesity onset (p = 0.003), and hyperlipoproteinemia type IV (p = 0.011). A high risk class might be thus identified among obese women, offering a more realistic approach for the primary prophylaxis of GS.

Emergency Health Care Information System for Bucharest-Romania.

The Emergency Health Care Information System (EHCIS) in Bucharest provides information about the whole activity of Dispatch Emergency Ambulance Service and Emergency Receiving Room of the 7 Hospitals, providing emergency health care in Bucharest over a MAN (Metropolitan Area Network). In each of these places a local network is located, containing a database server ORACLE. The link among LANs is made via switched lines. The Hospitals collect information only about emergency cases. The microstation represents station for emergency teams of Emergency Ambulance Service of Bucharest (EASB), distributed in all 6 districts of Bucharest. The system is structured accordingly with the working-groups existing in Dispatch, microstations and hospitals: registration operators (phone-operators) for administer the emergency requests/calls; a location for the medical coordinator which must to choose, in few seconds, the emergency team, accordingly with the case emergency degree; radio-operators which communicate with the teams in the field; a location for the manager of Dispatch, in order to provide a full-set of real-time medical and resources information; a registration operator at each microstation; a registration operator at each hospital. The data are registered in the ORACLE database on the central server. The client/server architecture assures the real time communication among all these locations. The system works 7 days/week, 24 hours/day.

Time trends in the incidence of hepatocellular carcinoma in liver cirrhosis. A retrospective necropsy study in a large Romanian town (1973-1992).

The present study retrospectively analyses all the necropsies (5, 112) performed in the two departments of pathology of a large Romanian town (Cluj-Napoca) during a ten-year interval (1983-1992) in order to estimate the prevalence of hepatocellular carcinoma (HCC). To evaluate the time trends of the association of HCC with liver cirrhosis, all cirrhotic subjects necropsied during two consecutive ten years intervals in one of the departments of pathology (Third Medical Clinic) were analysed. The prevalence of HCC was 8/100,000, with a derived incidence of 1.6/100,000 population/year. HCC was more frequent in males, and it occurred more frequently in cirrhotics (13.8%) than in noncirrhotics (0.6%) (p < 0.0001). The trends in the incidence of HCC in liver cirrhosis were evaluated for the 258 cirrhotic subjects necropsied during two ten year periods (1973-1982 and 1983-1992) in the Third Medical Clinic. HCC was found in cirrhotics older than 40 years, in proportions between 14 and 25% for the different age groups. There was an increasing tendency of HCC incidence in cirrhotic subjects over the last 20 years, significant for the 70-79 years age group. These data indicate a low incidence of HCC in our geographic area and suggest an increasing trend of the HCC association to liver cirrhosis over the last 20 years, more obvious in the advanced ages.

Increasing gallstone prevalence and cholecystectomy rate in a large Romanian town. A necropsy study.

To study whether the increasing prevalence of gallstone disease noted in a 100-year interval in a large Romanian town has continued in recent years, we analyzed all necropsies (5234) performed during 10 years (1983-1992) in Cluj-Napoca. Gallstone disease (GD) was defined as the presence of stones or the absence of the gallbladder due to cholecystectomy. The results obtained were compared to those of the previous 10-year period (1973-1982). We found a significant increase of GD both in men (6.9% to 9.8%) (P < 0.001) and women (17.1% to 21.7%) (P < 0.001). The ratio of women to men with GD decreased as compared to the first time period (1.4/1 vs 1.8/1). The actual age-standardized prevalence of GD was higher than that calculated for the first time period: 7.6% in men (5.0% in 1973-1982) and 16.9% in women (8.4% in 1973-1982) (P < 0.001). The necropsy cholecystectomy rate rose markedly; 42.1% of the GD men and 43.0% of the GD women had undergone operation during their life. The present study indicates a higher prevalence of GD in the Romanian town than previously found. The actual prevalence is comparable with that of other central European countries, but it is less than that found in England, Scotland, or Sweden.

[The value of various ultrasound criteria in objective assessment of acute reactive cholecystitis. A prospective follow-up study of ventilated intensive care patients]. / Stellenwert verschiedener Ultraschallkriterien zur Objektivierung einer reaktiven akuten Cholezystitis. Eine prospektive Verlaufsstudie bei intensivtherapiepflichtigen Beatmungspatienten.

Ultrasound of the abdomen was performed in 30 artificially respirated patients under intensive care conditions for 7 days per patient over a time period of 6 months to elucidate the therapeutic value of different ultrasonographic findings with respect to the diagnosis "reactive acute cholecystitis". Our results show, that neither the detection of concrements or sludge within the gallbladder, nor the transient dilatation of the bile duct, nor a transient wall-thickening or the occurrence of a three-layered wall of the gallbladder can be interpreted as reliable sonographic criteria for the occurrence of an acute reactive cholecystitis. From this we conclude, that reactive acute cholecystitis leading to the indication for cholecystectomy can only be diagnosed from the combination of clinical and sonographic findings. However, reactive acute cholecystitis can almost certainly be excluded, even in obscure upper abdominal symptoms, when the sonogram of the gallbladder is normal.

[Sonographic aspects of clinically suspected acute appendicitis]. / Sonographische Aspekte bei klinischem Verdacht auf akute Appendizitis.

Revealing a sensitivity of 97.5% and a specificity of 95.12% this study emphasizes the excellent diagnostic value of sonography in the elucidation of patients with clinical signs of "acute appendicitis". Evaluation of morphology on the one hand and maximal diameter of the organ and the organ wall on the other, in conjunction with the clinical presentation, allows a restrictive management of the surgical treatment and thus decreases the rate of negative laparotomy.