Luminescence properties of Ce-doped ZrO2 phosphors synthesized by combustion method.

Zr1-x Cex O2 with x = 0.005, 0.01, 0.02, and 0.03 samples were synthesized using a combustion technique. The X-ray diffraction results revealed that Ce-doped ZrO2 nanoparticles were in a monoclinic structure up to 1 mol% Ce concentration. The increase in the Ce concentration caused more distortion in the monoclinic structure of zirconia. The samples showed a mixed phase (monoclinic + tetragonal) beyond 1 mol% Ce content. The crystallite size (D) and strain (ε) were calculated from the Williamson-Hall equation. The D decreased from 25 ± 1 to 20 ± 1 nm and ε increased from 0.03 to 0.28% with an increase in Ce concentration. Photoluminescence (PL) spectra of Zr1-x Cex O2 showed emission in the blue region under an excitation wavelength of 290 nm. Zr0.995 Ce0.005 O2 showed the highest PL intensity with an average lifetime of 0.93 µs, and the PL intensity decreased with the increase in the Ce concentration. Thermoluminescence (TL) glow curves of Zr1-x Cex O2 were measured after gamma irradiation (500 Gy) with a heating rate of 5 K s-1 . The TL curve of Zr0.995 Ce0.005 O2 showed two prominent peaks at 412 K (peak 1) and 600 K (peak 2). The first TL glow peak was shifted towards a higher temperature at 440 K above 1 mol% Ce concentration. Repetitive TL measurements on the same aliquot exhibited excellent repeatability. Kinetic parameters associated with the TL peaks were calculated using the curve fitting method. Peak 1 followed non-first-order kinetics. The value of the activation energy of the 440 K peak was found to be 0.95 ± 0.01 eV for Zr0.99 Ce0.01 O2 . These findings showed that Zr1-x Cex O2 might be used in lighting and radiation dosimeter applications.

Rethinking vulnerability in city-systems: A methodological proposal to assess "urban entropy".

This paper aims at proposing a possible alternative point of view to investigate the vulnerability of urban systems. The basic ideal refers to the possibility of thinking about vulnerability as deriving by the interactions of several risks that can affect the urban system and by the interactions among them. In this sense, it is possible to refer to an "integrated territorial risk". Considering the city as a complex and dynamic system that while evolving produce entropy is the main theoretical reference supporting this study. The loss of energy during the evolution of the system corresponds to some conditions of inefficiency that involve the whole system and, as such, this lost energy can be assumed as a "systemic entropy". Is it possible to measure the levels of this vulnerability of the urban system when it stays in ordinary conditions, namely not during stress states that modify the state of equilibrium of the system itself? It is possible to assess the production of this "internal entropy"? In order to answer to these questions in mind, this study aims at analyzing dyscrasias that can occur within the main components of the urban system in order to individuate possible strategies able both to mitigate the fragility of the urban system and to improve its resilience.

[Adherence to recommendations to reduce the risk of Sudden infant Death Syndrome]. / Evaluación de la adherencia a las recomendaciones para disminuir el riesgo de Síndrome de Muerte Súbita del lactante.

INTRODUCTION: Recommendations for Sudden Infant Death Syndrome (SIDS) are available, although it is uncertain the degree of adherence to these measures. The aim of the study is to assess the adherence to recommendations to reduce the risk of SIDS, seeking factors associated to the noncompliance with these recommendations. PATIENTS AND METHOD: 468 infants were enrolled in two maternity hospitals, one public and one private. Postpartum and 4-month assessments were performed. A questionnaire was used adapting a model validated by the International Child Care Practices Study. RESULTS: Adherence to obstetric recommendations was higher (75.4%) than to pediatric recommendations (53.3%). Regarding pediatric recommendations, a compliance decrease was detected after 4 months. Follow-ups showed decrease in breastfeeding (p < 0.001 84.9% vs 48.6%) and supine position (61.2% vs 21.2%, p < 0.001). CONCLUSIONS: The decreased adherence to recommendations for SIDS prevention was mainly observed in younger and less educated women, who were not in a relationship and living in poor housing quality and crowded environments.

General and sex profile of women with partner affected by premature ejaculation: results of a large observational, non-interventional, cross-sectional, epidemiological study (IPER-F).

BACKGROUND: Couple distress is a crucial point in premature ejaculation (PE). PE has been associated with significant bother, interpersonal problems, and dissatisfaction with sexual intercourse for both men and their partners. OBJECTIVES: The primary objective of this study was to assess the effect of PE on female sexuality in female partners of men affected from PE. Secondary objectives were to assess the impact of PE on female sexual quality of life, to assess the presence of sexual problems of the male partner, and to evaluate the prevalence and characteristics of comorbidities. MATERIALS AND METHODS: Adult women aged 18 to 80 years old, sexually active, were randomly sampled from the patient lists of General Practitioners in Italy and were included in this observational, non-interventional, cross-sectional epidemiological study. Subjects were asked to fill: a general questionnaire regarding anthropometric data, lifestyle, marital status, education, occupation, economic conditions, general health status, comorbidities, and sexual habits; the Sexual Quality of Life Questionnaire-Female (SQoL-F); the Female Sexual Distress Scale (FSDS-R-PE); the Self-rating Depression Scale (SDS); and Self-rating Anxiety Scale (SAS). In addition, females reported about their partner's ejaculation time and the presence of sexual dysfunctions. RESULTS: A total of 3,104 women were included. Mean age was 45.1 years. Woman with PE partners presented a higher percentage of sexual dysfunction and reported more anxiety compared with female partners of men not affected from PE (42.69% vs. 20.56% and 30.95% vs. 15,34%, respectively). In addition, they referred more sexual dysfunction in their partners. Hypertension, hypercholesterolemia, arthritis, heart diseases, thyroid disease, a history of menopause, or hysterectomy resulted in significantly more prevalence in women with PE partners. DISCUSSION AND CONCLUSIONS: Female partners of PE patients present an increased prevalence of sexual distress, a reduced quality of sexual life, and an increased anxiety score when compared to women whose partners are not affected from PE.

Endoscopic ultrasound-fine needle aspiration (EUS-FNA) for pancreatic lesions: effectiveness in clinical practice.

BACKGROUND: Diagnosis of pancreatic masses is often difficult. Endoscopic ultrasound-fine needle aspiration has been proposed as the best single-step strategy. AIMS: To prospectively evaluate feasibility, effectiveness and safety of endoscopic ultrasound-fine needle aspiration of pancreatic masses in a consecutive study of unselected patients. METHODS: Two hundred ninety-three patients were enrolled in two referral Hospitals in Northern Italy. All patients were referred either due to the presence of imaging test abnormalities (suspected or evident masses, or features indirectly suggesting the presence of a mass) or due to clinical or biochemical findings suggesting pancreatic cancer in the absence of positive imaging. All patients underwent linear array endoscopic ultrasound and, when indicated, fine needle aspiration. All procedures were recorded prospectively. The final diagnosis was established at the end of follow-up or when the patients underwent surgery or died. RESULTS: Fine needle aspiration was indicated in 246 of 293 cases (84%), considered technically feasible in 232 of 246 cases (94%) and gave adequate samples for histopathological diagnosis in 204 of 232 cases (88%). Endoscopic ultrasound sensitivity, specificity and accuracy were 79, 60 and 72%, respectively; the corresponding figures for endoscopic ultrasound-fine needle aspiration were 80, 86 and 82%. There was good agreement with final diagnosis for endoscopic ultrasound-fine needle aspiration (kappa 0.673, 95%CI 0.592-0.753), greater than that for endoscopic ultrasound alone (kappa 0.515, 95%CI 0.425-0.605). There was one case of intracystic haemorrhage and one case of transient hyperthermia (0.3%). CONCLUSIONS: Endoscopic ultrasound-fine needle aspiration of pancreatic masses seems to be feasible, effective and safe in this consecutive study of patients.

[Endoscopic ultrasound-fine needle aspiration (EUS-FNA) for pancreatic lesions: effectiveness in clinical practice]. / Agoaspirato con ago sottile sotto guida ecoendoscopica nelle lesioni pancreatiche: efficacia nella pratica clinica.

UNLABELLED: Endoscopic ultrasound-fine needle aspiration (EUS-FNA) was shown to be a highly reliable and a very effective diagnostic technique, both based on data from clinical trials and from large clinical practice studies. EUS-FNA results are reported to be in good-to-very good agreement with the final diagnosis, and the agreement significantly exceeded the chance agreement. The overall sensitivity and specificity of EUS and of EUS-FNA are very good. EUS-FNA is an effective diagnostic technique for the evaluation of pancreatic lesions, either reported with other imaging tests or suspected on the basis of clinical and biochemical features. EUS-FNA may be performed in most cases, and the results of EUS-FNA are particularly important for their excellent positive predictive value. Nonetheless, in a few cases EUS-FNA can not be feasible, or can give false negative or inconclusive RESULTS: The main practical consequence is that before referring patients to surgeons or oncologists, EUS-FNA should be considered as the best diagnostic strategy, since tissue is still the issue' . In a prospective two-centers consecutive series from Italy, FNA did not give any false positive diagnoses of malignancy, and reduced the number of indeterminate diagnoses; moreover, FNA significantly increased the specificity of diagnosis, while sensitivity was unchanged.

Role of endoscopic ultrasound in biliary and unexplained pancreatitis.

In the Western world, gallstone disease accounts for approximately half of the cases of acute pancreatitis. The benefit of therapeutic endoscopic retrograde cholangiopancreatography (ERCP) has been clearly proven for this disease. On the basis of history, laboratory, and noninvasive imaging studies, about 10-30% of patients with acute pancreatitis have no apparent aetiology. This is critical because it limits the optimal therapeutic management and the prevention of recurrence. Endoscopic ultrasound (EUS) has emerged as an important procedure to clarify the aetiology of acute pancreatitis. After extensive investigation that included EUS, 8-20% of episodes remained idiopathic. Moreover, EUS carried minimal risk when compared to ERCP. The present short review attempts to update on the indications for the employment of EUS in the diagnosis of biliary stones as well as in the clarification of aetiology in the case of unexplained pancreatitis.

Extensive study on physicochemical properties of polychlorinated biphenyls in a commercial ion trap mass spectrometer, relevance in analytical and environmental chemistry.

Polychlorinated biphenyls (PCBs) exist as 209 congeners, consisting of biphenyl molecules, where the number and substitution positions of halogen atoms are known to affect industrial uses, environmental transport mechanisms, distribution, fate, and toxicity. The complexity of the problem requires accurate physicochemical studies of an increasing number of congeners in order to understand the environmental and biological processes at play. This work presents a systematic study on the thermodynamic and kinetic properties of PCBs by quadrupole ion trap mass spectrometry. A clear relationship between structure and behavior of PCBs in mass spectrometry experiments has been observed. Overall data demonstrate that di-ortho congeners show lower thermodynamic stability and higher fragmentation rate than non/mono-ortho. Congeners follow different fragmentation mechanisms according to the number of chlorine atoms in ortho position of the biphenyl system. Experimental kinetic curves of mono/non-ortho and di-ortho congeners show a strong similarity with classical first-order kinetics curves; in particular, di-ortho congeners follow a first-order consecutive reaction, while mono/non-ortho follow a first-order parallel reaction. For each studied congener, the kinetic constant of reaction (fragmentation) has been determined. Data support environmental levels and biochemical transformations described in literature. The general picture of the PCB behavior inside a quadrupole ion trap provides the basis for the development of reliable and cost-effective analytical methods to the determination of ultra-low level trace of PCB congeners.

Patient re-training in peritoneal dialysis: why and when it is needed.

The aim of this multicenter, quantitative, observational study was to analyze compliance and re-training needs of patients on peritoneal dialysis (PD) through the assessment of patient knowledge (with a Patient Questionnaire; phase 1) and patient behavior (home visit with a Score Card; phase 2). A total of 353 patients from 11 Italian centers participated in the first phase and 191 patients from nine centers in the second phase. Overall, 66% of questions on the Patient Questionnaire were answered correctly. Correct answers were more frequent in females than males, in patients under 55 years of age, and in those with higher education. The lowest rate of correct answers involved questions related to diet and physical activity (67% and 51%, respectively). Data collected during the home visit showed that 25% of patients were partially compliant with their drug therapy. Twenty-three percent of patients were non-compliant with the exchange protocol procedures, with a significant association between compliance and the incidence of peritonitis, and 11% were non-compliant with the exit-site protocol procedures without a statistically significant correlation to peritonitis. By combining the two evaluations, we found that approximately one-third (29%) of patients needed reinforcement of knowledge and ability to correctly perform PD as related to infection control and 27% for the correct use of drugs. Looking at the combined evaluation of infection control and drug use, results showed that 47% of patients needed re-training. This need for re-training was greater for younger patients (less than 55 years old), patients with lower education degree and patients in the early or late phase of PD therapy (less than 18 months or more than 36 months). Gender and degree of autonomy had no effect on the need for re-training.

The hazardous burden of Herpesviridae in inflammatory bowel disease: the case of refractory severe ulcerative colitis.

BACKGROUND: Herpesviridae infection or spread may be a hazard in immunodepressed patients. In the field of inflammatory bowel disease, refractory severe ulcerative colitis is a challenging condition, closely associated to immunosuppression both for inanition due to the disease activity and for immunosuppressive treatments. Cytomegalovirus (CMV) has been proposed as a major cause of refractoriness, while other Herpesviridae may be a risk factor in the long-term follow-up. AIM OF THE STUDY: To evaluate the positivity rates of CMV, Epstein-Barr (EBV) and Human herpes virus-8 (HHV8) in a consecutive group of ulcerative colitis patients who underwent colectomy for refractoriness to medical treatment compared to a control group, using state of the art methods. PATIENTS AND METHODS: Colonic specimens from 24 consecutive patients with ulcerative colitis submitted to colectomy for refractoriness and from 20 controls (submitted to colectomy for colorectal cancer) were studied. Standard histology and immunohistochemistry (IHC) for CMV and specific polymerase chain-reaction (PCR) for CMV, EBV and HHV8 were carried out. RESULTS: Regarding CMV, 1 case (4%) was positive at histology and IHC, whereas 3 cases (13%) were positive at PCR, compared to none in the control group (p=0.239). For EBV 2 cases (8%) and 2 controls (10%) were positive at PCR. None of the cases or of controls was positive for HHV8. The only clinical characteristic independently associated to CMV positivity was the white blood cell count at admission, higher among CMV positive patients (p<0.001). At the end of the post-surgery follow-up (median 7.3 years) none of the CMV positive cases experienced pouchitis, compared to 3/21 (14%) of the CMV negative cases (p=1.000). DISCUSSION: Our data suggest that CMV is uncommon (13%), even though PCR techniques, considered to be the most sensitive tools, were used for virus detection and the study population is made by highly selected patients with definite refractoriness. EBV and HHV8 may represent a theoretical risk of immunosuppressive therapy because of their potential role as cancer triggers; however in our study, results seem to be reassuring that UC patients undergoing immunosuppressive therapy are not exposed to an excessive risk of viral infection.

Multicentre retrospective study on endoscopic ultrasound complications.

BACKGROUND: Endoscopic ultrasonography, both conventional and interventional, has been used increasingly during the past 20 years and is deemed a safe technique. Its complication rate, however, has been studied to only a limited extent. This multicentre investigation sought to establish the complication rate for a large number of endoscopic ultrasonography procedures. METHODS: By means of a questionnaire, we collected data from six centres on the number of endoscopic ultrasonography examinations performed and divided them into conventional and interventional examinations of the upper and lower gastrointestinal tract. Information was obtained on technical modalities such as instruments and sedation and, for interventional endoscopic ultrasonography, indications, pre-procedural exams and technical details (needle calibre, number of passes) had to be specified. Complications were classified as mild, moderate, severe or fatal and their onset as immediate, early or late. Variables that entered into the analysis of complication rate included type of endoscopic ultrasonography instrument used, type and site of lesion biopsied, number of needle passes and operator experience. RESULTS: Eleven thousand five hundred thirty nine endoscopic ultrasonographic procedures were reported, of which 10,731 were conventional and 808 interventional. No deaths occurred; there were 14 (0.12%) complications, 5 (0.046%) of them following conventional endoscopic ultrasonography and 9 (1.11%) after interventional endoscopic ultrasonography. Seven complications were mild, four moderate and three severe. CONCLUSIONS: Both conventional and interventional endoscopic ultrasonography were confirmed to be acceptably safe techniques.

Establishment and characterization of a human adrenocortical carcinoma cell line that expresses multiple pathways of steroid biosynthesis.

We established a continuous cell line, NCI-H295, from an invasive primary adrenocortical carcinoma. The cell line was established in a fully defined medium (HITES) and later could be adapted for growth in a simple medium supplemented only with selenium, insulin, and transferrin and devoid of serum, steroids, fibroblast growth factor, and a source of exogenous cholesterol. NCI-H295 cells had a relatively long population doubling time and were tumorigenic when inoculated s.c. into athymic nude mice. The cultured cells had ultrastructural features of steroid-secreting cells and contained complex cytogenetic abnormalities including the presence of multiple marker chromosomes. Steroid analyses (radioimmunoassays and mass spectrometry), performed 7 to 9 years after culture initiation, demonstrated secretion of more than 30 steroids characteristic of adrenocortical cells. Total unconjugated steroid secretion in serum-supplemented medium was 2.83 micrograms/10(6) cells/24 h and about 4-fold less in serum-free medium. The major pathway of pregnenolone metabolism in NCI-H295 cells is androgen synthesis, with formation of dehydroepiandrosterone, androstenedione, testotesterone, and at least three sulfated androgens, as well as estrogens. In addition, formation of cortisol, corticosterone, aldosterone, and 11 beta-hydroxyandrostenidione indicated the presence of 11 beta-hydroxylase. Thus, multiple pathways of steroidogenesis are expressed by NCI-H295 cells, including formation of corticosteroids, mineralocorticoids, androgens, and estrogens. Our findings indicate the presence in NCI-H295 cells of all of the major adrenocortical enzyme systems, including 11 beta-hydroxylase, desmolase, 21 alpha-hydroxylase, 17 alpha-hydroxylase, 18-hydroxylase, lyase, sulfokinase, and aromatase. The NCI-H295 cell line should prove of value in studying the regulation, metabolic pathways, and enzymes involved in steroid formation and secretion. In addition, it may provide insights into the biology and treatment of adrenocortical carcinoma.

Effects of alpha1-blockers on urodynamic parameters of bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic enlargement: a review.

α1-adrenergic receptors blockers (ABs) are recommended as first-line medical therapy in men with Lower Urinary Tract Symptoms suggestive of Benign Prostatic Enlargement (LUTS/BPE). Available ABs include: terazosin, doxazosin, tamsulosin, naftopidil, alfuzosin and silodosin. These agents have different profiles of selectivity for α1-adrenergic receptors subtypes. All these agents are efficacious in improving both storage and voiding LUTS. In recent years the efficacy of ABs in improving urodynamic parameters of bladder outlet obstruction (BOO) has been questioned. We reviewed literature evidences about the effects of available ABs on invasive urodynamic parameters of BOO in men with LUTS/BPE. The impact of ABs therapy on urodynamic parameters indicative of BOO has been evaluated for all currently approved drugs. Available data demonstrate improvements in terms of both free uroflowmetry and pressure-flow parameters. While the impact of ABs on maximum urinary flow is clinically modest, the improvement of detrusor pressure at maximum urinary flow is more robust. Only few studies exist that directly compare the urodynamic effects of a small number of ABs. According to these studies there are no differences among ABs in terms of urodynamic efficacy. Indirect comparison of ABs suggests greater effectiveness of silodosin in terms of detrusor pressure at maximum urinary flow reduction. Studies that stratified populations based upon the degree of obstruction at baseline demonstrated greater urodynamic changes in patients with baseline BOO with respect to the unobstructed patients. Globally, the quality of studies available is low and there is considerable heterogeneity among studies.

Therapeutic ERCP in paediatric patients.

BACKGROUND: Major limitations of endoscopic retrograde cholangiopancreatography in paediatric populations are a low incidence of biliopancreatic disease among children, the equipment dimensions (size of endoscopes and devices) and the increasing role of MR-cholangiopancreatography in the field of diagnostic indications. Aim of this study was to evaluate the diagnostic and therapeutic yields of endoscopic retrograde cholangiopancreatography for biliopancreatic diseases in a paediatric population. METHODS: Between 1996 and 2002, 48 endoscopic retrograde cholangiopancreatographies were performed in 38 children aged 4 weeks to 17 years as part of the diagnostic evaluation for suspected pancreatic or biliary tract disease. Endoscopic retrograde cholangiopancreatography was carried out under general anaesthesia, using prototype paediatric duodenoscopes or standard duodenoscopes in children younger or older than 18 months, respectively. RESULTS: The indications to perform endoscopic retrograde cholangiopancreatography were common bile duct stones (14 children), biliopancreatic abnormalities (8), primary sclerosing cholangitis (2), Wirsung disruption (1), biliary leakage (1), cholestasis (4) and pancreatitis (8). Cannulation was successful in all patients but one. Sphincterotomy together with stone extraction or stent insertion was performed in 30/38 patients. Immediate complications were mild and treated conservatively. CONCLUSIONS: Diagnostic and therapeutic endoscopic retrograde cholangiopancreatography can be used safely and effectively in the management of biliopancreatic diseases in childhood as well. Indications, endoscopic techniques and complications are similar to those reported for adult patients.

Suramin in adrenal cancer: modulation of steroid hormone production, cytotoxicity in vitro, and clinical antitumor effect.

Suramin, a drug known to have antiparasitic effects, has been previously shown to have adrenocorticolytic activity in primates. We now confirm preferential accumulation of this compound in the normal adrenal gland, evaluate its in vitro effect against two human adrenocortical carcinoma cell lines (SW-13 and NCI-H295), and report the clinical activity of suramin in 17 patients with metastatic adrenocortical carcinoma. Inhibition of colony formation occurred in both adrenal cell lines in vitro at concentrations that are clinically achievable in humans. In addition, suramin concentrations as low as 100 micrograms/mL were able to inhibit glucocorticoid, mineralocorticoid, and androgen production by the NCI-H295 cell line. Of 16 patients with adrenocortical carcinoma now evaluable for tumor response, 2 achieved a partial response, 2 had a minor response, and 5 remained with stable disease for periods ranging from 3-10 months; the remainder progressed. One of 7 patients with excessive steroid hormone production achieved a partial normalization of her steroid levels for the duration of suramin therapy in the setting of radiographic disease stabilization. An additional patient treated off-study for lack of radiographically measurable disease, achieved complete normalization of plasma aldosterone levels. We conclude that suramin preferentially accumulates in adrenal cells, induces cytotoxicity and significant down-regulation of steroid hormone production in vitro, and has some therapeutic efficacy as a single agent in patients with metastatic adrenocortical carcinoma.

Clinical and experimental evidence of inhibition of testosterone production by suramin.

The effect of suramin on testosterone production was evaluated in cancer patients, adult male rats, rat Leydig cells, and NCI-H295 human adrenal cancer cells. Testosterone plasma levels markedly decreased in 14 patients receiving suramin as a therapy for refractory cancer, and in 8 of them, the plasma LH and/or FSH levels increased beyond the normal range. The hCG stimulation test (5000 IU, im) was performed in 8 patients and induced an average 2.1-fold increase in testosterone levels over baseline values. Testicular histology after suramin treatment was available in 1 patient who died of progressive disease; this revealed atrophy of seminiferous tubules and reduced Leydig cells in the interstitium. A significant reduction in plasma testosterone was also observed in rats given 18 mg/kg suramin, ip, twice weekly for 8 weeks, whereas plasma LH and FSH levels did not change significantly. Cytohistochemistry of testes from suramin-treated rats showed a reduced number of 3 beta-hydroxysteroid dehydrogenase-positive cells within the interstitium compared to controls, and light microscopy revealed severe impairment of spermatogenesis. Suramin inhibited the production of testosterone by isolated rat Leydig cells as well as the conversion of pregnenolone to progesterone by the 3 beta-hydroxysteroid dehydrogenase enzyme extracted from rat testes, with 50% inhibitory concentrations (IC50 values) of 108.2 and 87.5 micrograms/mL, respectively. Furthermore, suramin reduced the release of testosterone into the culture medium of NCI-H295 adrenal cancer cells with IC50 values of 91.2 and 83.9 micrograms/mL after 6 and 12 days, respectively. These data provide the first evidence in patients that suramin treatment produces a marked reduction in the circulating levels of testosterone, a result that was also obtained in experimental models.

Adaptive control with feedback strategies for suramin dosing.

Suramin, a drug used in the treatment of parasitic diseases, is currently being evaluated in clinical trials as an antineoplastic agent. The use of therapeutic drug monitoring and adaptive control with feedback in clinical trials of suramin was initially motivated by an association between acute neurologic toxicity and plasma suramin concentrations in excess of 350 micrograms/ml. We have prospectively examined the performance of both two- and three-compartment population pharmacokinetic models in controlling plasma suramin concentrations and have found that a three-compartment model best describes this drug. No correlation was found between the clearance of suramin and creatinine clearance, as had been previously hypothesized. The low systemic clearance of suramin and the number of parameters required to describe the three-compartment model suggest the need for a bayesian approach to the estimation of individual pharmacokinetics.

Suramin-induced polyneuropathy.

We report the development of a severe polyneuropathy in 4 of 38 patients who were receiving parenteral suramin therapy for the treatment of various underlying malignancies. In 2 of these patients, the neuropathy progressed to generalized flaccid paralysis with bulbar and respiratory involvement, requiring endotracheal intubation and ICU monitoring. EMG and nerve conduction studies showed evidence of conduction block, suggestive of a demyelinating polyneuropathy. After several weeks, both patients improved clinically. The other 2 patients developed a reversible neuropathy with flaccid paresis of the limbs but without bulbar or respiratory compromise. No immediate response to plasmapheresis was noted. All 4 patients demonstrated an elevated CSF protein in the acute phase of their neuropathy, which declined or returned to normal during recovery. The development of polyneuropathy correlated with the maximum plasma suramin level, with an estimated 40% risk of developing neurotoxicity in those patients whose maximum level was 350 micrograms/ml or greater. No correlation could be made with the total dose of suramin administered or with the duration of therapy. Two of these 4 patients manifested tumor shrinkage while receiving suramin therapy. We conclude that suramin, a promising antineoplastic agent, is capable of inducing a severe sensorimotor polyneuropathy which appears to be related to the plasma concentration of suramin. Serial measurement of the plasma concentration during suramin therapy is recommended.

Review article: Crohn's disease: monitoring disease activity.

A global measurement of Crohn's disease activity, comprising clinical, endoscopic, biochemical and pathological features is not available yet and perhaps is unobtainable. In this review we analyse the most used and validated clinical indices (Crohn's Disease Activity Index [CDAI], Perianal Disease Activity Index [PDAI], fistula drainage assessment), quality of life scores (Inflammatory Bowel Disease Questionnaire [IBDQ]), sub-clinical markers (C-reactive protein, faecal calprotectin, intestinal permeability) and endoscopic indices (Crohn's Disease Endoscopic Index of Severity [CDEIS]/Simple Endoscopic Score for Crohn's Disease [SES-CD], Rutgeeerts' score for postsurgical recurrence). We also review the main advantages and disadvantages of each of these scoring systems. All these indices are rather complex and time-consuming, therefore their use is limited to clinical trials. In everyday clinical practice most gastroenterologists rely on their global clinical judgement, which is less reproducible, but simpler for decision-making.

Review article: medical treatment of severe ulcerative colitis.

Approximately 15% of patients with ulcerative colitis have a severe attack requiring hospitalization at some time during their illness. This treatment leads to a remission in 60-80% of patients and non-responders may require a total colectomy. Mortality in severe episodes of ulcerative colitis decreased from 31-61% in the 1950s to 5-9% in the 1960s thanks to the introduction of steroids and to a policy of early colectomy. Recently, some new drugs have been shown to be effective in the treatment of severe steroid-refractory ulcerative colitis. This review concentrates on the clinical evaluation, prognostic factors and new developments in medical therapy in severe ulcerative colitis. A retrospective evaluation of a consecutive series of patients with severe ulcerative colitis admitted to a Gastroenterology Department in Torino, Italy, is also reported.