Co-Design as Enabling Factor for Patient-Centred Healthcare: A Bibliometric Literature Review

Service design and in particular co-design are approaches able to align with the need of healthcare contexts of value-based and patient-centered processing through a participatory design of services. The purpose of this study is to identify the characteristics of co-design and its applicability to the reengineering of healthcare services, as well as to detect the peculiarities of the application of this approach in different geographical contexts. The methodology applied for the review, Systematic Literature Network Analysis (SLNA), combines qualitative and quantitative perspectives. In detail, the analysis applied the paper citation networks and the co-word network analysis to detect the main research trends over time and to identify the most relevant publications. The results of the analysis highlight the backbone of literature on the application of co-design in healthcare as well as the advantages and the critical factors of the approach. Three main literature streams emerged concerning the integration of the approach at meso and micro level, the implementation of co-design at mega and macro level, and the impacts on non-clinical related outcomes. Moreover, the findings underline differences in co-design in terms of impacts and success factors in developed countries and economies in transition or developing countries. The analysis shows the potentially added value of the application of a participatory approach to the design and redesign of healthcare services both at different levels of the healthcare organization and in the contexts of developed countries and economies in transition or developing countries. The evidence also highlights potentialities and critical success factors of the application of co-design in healthcare services redesign.

Cost of illness of Primary Biliary Cholangitis - a population-based study

BACKGROUND

The economic burden of Primary Biliary Cholangitis (PBC) has not been investigated at population-level. Aim of this study was to estimate the cost of illness of PBC in Lombardy, Italy.

METHODS

Individuals with PBC were identified through ICD-9-CM code 571.6 and/or medical exemption code 008.571.6, from the Banca Dati Assistito of Lombardy. Only health services (outpatient, inpatient activities and drugs) related to PBC were considered to estimate direct medical costs in 2017.

RESULTS

We identified 970 adult patients (83.5% females) with a mean age of 61 years. Global annual costs were equal to € 913,763 (€ 942 per patient), with € 459,506 (50.3%, € 474 per patient) deriving from hospitalizations (mostly due to liver transplantation, 30.5%, and cirrhosis complications, 20.6%). Costs from outpatient activities were € 109,090 (11.9%, € 112 per patient).

CONCLUSIONS

This study provides an overview of the costs attributed to PBC care and management, mainly related to hospitalizations for cirrhosis complications, which is necessary for assuring cost-effective introduction of novel therapies. Additional studies focused on indirect cost, e.g. overall loss of productivity, are warranted.

Highly integrated workflows for exploring cardiovascular conditions: Exemplars of precision medicine in Alzheimer's disease and aortic dissection

For precision medicine to be implemented through the lens of in silico technology, it is imperative that biophysical research workflows offer insight into treatments that are specific to a particular illness and to a particular subject. The boundaries of precision medicine can be extended using multiscale, biophysics-centred workflows that consider the fundamental underpinnings of the constituents of cells and tissues and their dynamic environments. Utilising numerical techniques that can capture the broad spectrum of biological flows within complex, deformable and permeable organs and tissues is of paramount importance when considering the core prerequisites of any state-of-the-art precision medicine pipeline. In this work, a succinct breakdown of two precision medicine pipelines developed within two Virtual Physiological Human (VPH) projects are given. The first workflow is targeted on the trajectory of Alzheimer's Disease, and caters for novel hypothesis testing through a multicompartmental poroelastic model which is integrated with a high throughput imaging workflow and subject-specific blood flow variability model. The second workflow gives rise to the patient specific exploration of Aortic Dissections via a multi-scale and compliant model, harnessing imaging, computational fluid-dynamics (CFD) and dynamic boundary conditions. Results relating to the first workflow include some core outputs of the multiporoelastic modelling framework, and the representation of peri-arterial swelling and peri-venous drainage solution fields. The latter solution fields were statistically analysed for a cohort of thirty-five subjects (stratified with respect to disease status, gender and activity level). The second workflow allowed for a better understanding of complex aortic dissection cases utilising both a rigid-wall model informed by minimal and clinically common datasets as well as a moving-wall model informed by rich datasets.

Organisational and financial consequences of the early discharge of patients treated for acute bacterial skin and skin structure infection and osteomyelitis in infectious disease departments in Greece, Italy and Spain: a scenario analysis

OBJECTIVE

The aim of the analysis is to assess the organisational and economic consequences of adopting an early discharge strategy for the treatment of acute bacterial skin and skin structure infection (ABSSSI) and osteomyelitis within infectious disease departments.

SETTING

Infectious disease departments in Greece, Italy and Spain.

PARTICIPANTS

No patients were involved in the analysis performed.

INTERVENTIONS

An analytic framework was developed to consider two alternative scenarios: standard hospitalisation care or an early discharge strategy for patients hospitalised due to ABSSSI and osteomyelitis, from the perspective of the National Health Services of Greece, Italy and Spain. The variables considered were: the number of annual hospitalisations eligible for early discharge, the antibiotic treatments considered (ie, oral antibiotics and intravenous long-acting antibiotics), diagnosis-related group (DRG) reimbursements, number of days of hospitalisation, incidence and costs of hospital-acquired infections, additional follow-up visits and intravenous administrations. Data were based on published literature and expert opinions.

PRIMARY AND SECONDARY OUTCOME MEASURES

Number of days of hospitalisation avoided and direct medical costs avoided.

RESULTS

The total number of days of hospitalisation avoided on a yearly basis would be between 2216 and 5595 in Greece (-8/-21 hospital beds), between 15 848 and 38 444 in Italy (-57/-135 hospital beds) and between 7529 and 23 520 in Spain (-27/-85 hospital beds). From an economic perspective, the impact of the early discharge scenario is a reduction between €45 036 and €149 552 in Greece, a reduction between €182 132 and €437 990 in Italy and a reduction between €292 284 and €884 035 in Spain.

CONCLUSIONS

The early discharge strategy presented would have a positive organisational impact on National Health Services, leading to potential savings in beds, and to a reduction of hospital-acquired infections and costs.

A NOVEL TEPC FOR MICRODOSIMETRY AT NANOMETRIC LEVEL: RESPONSE AGAINST DIFFERENT NEUTRON FIELDS

Tissue equivalent proportional counter (TEPC) is the most accurate device for measuring the microdosimetric properties of a particle beam, nevertheless no detailed information on the track structure of the impinging particles can be obtained, since the lower operation limit of common TEPCs is ~0.3 μm. On the other hand, the pattern of particle interactions at the nanometer level is measured by only three different nanodosimeters worldwide: practical instruments are not yet available. In order to partially fill the gap between microdosimetry and track-nanodosimetry, a low-pressure avalanche-confinement TEPC was recently designed and constructed for simulating tissue-equivalent sites down to the nanometric region. The present article aims at describing the response of this newly developed TEPC in the range 0.3 μm-25 nm against a fast neutron field from a 241Am-Be source and a quasi-monoenergetic neutron beam. The experimental results are in good agreement with Monte Carlo simulations carried out with the FLUKA code.

Cost-effectiveness analysis of the use of daclatasvir + sofosbuvir + ribavirin (16 weeks and 12 weeks) vs sofosbuvir + ribavirin (16 weeks and 24 weeks) for the treatment of cirrhotic patients affected with hepatitis C virus genotype 3 in Italy

The WHO estimates that more than 185 million people are infected with hepatitis C virus (HCV) worldwide. The aim of the study is to assess the incremental cost-effectiveness ratio (ICER) of the use of daclatasvir (DCV) + sofosbuvir (SOF) + ribavirin (RBV) for 12 and 16 weeks vs SOF + RBV for 16 and 24 weeks for the treatment of genotype 3 HCV infected cirrhotic patients from the Italian National Health Service (NHS) perspective. A published cohort-based Markov model was used to perform the analysis estimating the lifetime direct medical costs associated with the management of the pathology and the quality adjusted life years gained by patients. Deterministic and probabilistic sensitivity analyses were performed to test the robustness of the results. SOF + RBV for 16 weeks was excluded from the analysis due to the significant lower effectiveness, compared with SOF + RBV for 24 weeks (51% vs 79%). DCV + SOF + RBV would increase QALYs and costs in all the comparisons: the ICERs obtained comparing DCV + SOF + RBV for 12 and 16 weeks with SOF + RBV for 24 weeks (reference scenario) are 38,572 €/QALY and 16,436 €/QALY, respectively, both below the 40,000 €/QALY threshold identified by the Italian Health Economics Association. Sensitivity analyses confirmed the robustness of the results. The use of DCV + SOF + RBV is likely to be cost-effective compared with SOF + RBV (for 24 weeks) for the treatment of cirrhotic patients infected with genotype 3 HCV considering a threshold value of 40,000 €/QALY.

Cost-effectiveness analysis of dolutegravir plus backbone compared with raltegravir plus backbone, darunavir+ritonavir plus backbone and efavirenz/tenofovir/emtricitabine in treatment naïve and experienced HIV-positive patients

Background

In January 2014, the European Medicines Agency issued a marketing authorization for dolutegravir (DTG), a second-generation integrase strand transfer inhibitor for HIV treatment. The study aimed at determining the incremental cost-effectiveness ratio (ICER) of the use of DTG+backbone compared with raltegravir (RAL)+backbone, darunavir (DRV)+ritonavir(r)+backbone and efavirenz/tenofovir/emtricitabine (EFV/TDF/FTC) in HIV-positive treatment-naïve patients and compared with RAL+backbone in treatment-experienced patients, from the Italian National Health Service’s point of view.

Materials and methods

A published Monte Carlo Individual Simulation Model (ARAMIS-DTG model) was used to perform the analysis. Patients pass through mutually exclusive health states (defined in terms of diagnosis of HIV with or without opportunistic infections [OIs] and cardiovascular disease [CVD]) and successive lines of therapy. The model considers costs (2014) and quality of life per monthly cycle in a lifetime horizon. Costs and quality-adjusted life years (QALYs) are dependent on OI, CVD, AIDS events, adverse events and antiretroviral therapies.

Results

In treatment-naïve patients, DTG dominates RAL; compared with DRV/r, the ICER obtained is of 38,586 €/QALY (6,170 €/QALY in patients with high viral load) and over EFV/TDF/FTC, DTG generates an ICER of 33,664 €/QALY. In treatment-experienced patients, DTG compared to RAL leads to an ICER of 12,074 €/QALY.

Conclusion

The use of DTG+backbone may be cost effective in treatment-naïve and treatment-experienced patients compared with RAL+backbone and in treatment-naïve patients compared with DRV/r+backbone and EFV/TDF/FTC considering a threshold of 40,000 €/QALY.

Financial and feasibility implications of the treatment of hepatitis C virus in Italy: scenarios and perspectives

Background

Hepatitis C virus (HCV) affects an estimated number of people between 130 million and 210 million worldwide. In the next few years, the Italian National Health Service will face a growing trend of patients requiring HCV antiviral treatments. The aim of the analysis was to estimate the time horizon in which it would be possible to treat HCV-infected patients and the related direct medical costs (antiviral treatment and monitoring activities) from the Italian National Health Service point of view.

Methodology

In order to estimate the number of HCV-infected patients in Italy, we considered a top-down (considering published data) and a bottom-up approach. The number of years needed for treatment and related direct costs were estimated through the development of a static deterministic model.

Results

The estimated number of HCV-infected patients in Italy varies from 2.7 (estimated through a top-down approach) to 0.6 million (estimated through a bottom-up approach) and 0.3 million (measured through a bottom-up approach). Considering the last two scenarios and the use of interferon-free therapies for 50,000 patients per year, treatment for HCV-infected patients could be at a cost of €13.7 billion and €7.0 billion by 2030 and 2023, respectively.

Conclusion

The treatment for HCV-infected patients in Italy is a challenging target for the financial implications of patient care. HCV infection could be controlled or eliminated in a 10- to 15-year time horizon. The cost of treatment can hardly be dealt with using the traditional economic tools but should be faced through multiyear investments, as health benefits are expected in the long period. National Health Service stakeholders (industry, government, insurance, and also patients) will have to identify suitable financial instruments to face the new expenditure required.

Budget impact analysis of antiretroviral less drug regimen simplification in HIV-positive patients on the Italian National Health Service

Background

Deintensification and less drug regimen (LDR) antiretroviral therapy (ART) strategies have proved to be effective in terms of maintaining viral suppression in human immunodeficiency virus (HIV)-positive patients, increasing tolerability, and reducing toxicity of antiretroviral drugs administered to patients. However, the economic impact of these strategies have not been widely investigated. The aim of the study is to evaluate the economic impact that ART LDR could have on the Italian National Health Service (INHS) budget.

Methods

A budget impact model was structured to assess the potential savings for the INHS by the use of ART LDR for HIV-positive patients with a 3 year perspective. Data concerning ART cost, patient distribution within different ARTs, and probabilities for patients to change ART on a yearly basis were collected within four Italian infectious diseases departments, providing ART to 13.7% of the total number of patients receiving ART in Italy.

Results

The LDR investigated (protease inhibitor-based dual and monotherapies) led to savings for the hospitals involved when compared to the “do nothing” scenario on a 3 year basis, between 6.7% (23.11 million €) and 12.8% (44.32 million €) of the total ART expenditures. The mean yearly cost per patient is reduced from 9,875 € in the do nothing scenario to a range between 9,218 € and 8,615 €. The use of these strategies within the four departments involved would have led to a reduction of ART expenditures for the INHS of between 1.1% and 2.1% in 3 years.

Conclusion

ART LDR simplification would have a significant impact in the reduction of ART-related costs within the hospitals involved in the study. These strategies could therefore be addressed as a sustainable answer to the public financing reduction observed within the INHS in the last year, allowing therapies to be dispensed without affecting the quality of the services provided.

Health technology assessment in the HIV setting: the case of monotherapy

Despite the success of multiple-drug therapy regimens, the idea of treating human immunodeficiency virus (HIV) infection with fewer drugs is captivating due to issues of convenience, long-term toxicities and costs. This study investigated the impact on a local health budget of the introduction of a protease inhibitor (PI)-based antiretroviral monotherapy. An analysis of 23,721 administrative records of HIV-infected patients and a health technology assessment (HTA) were performed to assess cost-effectiveness, budget, organizational, ethics, and equity impact. Data showed that monotherapy had a annual cost of € 7,076 (patient with undetectable viral load) and € 7,860 (patient with detectable viral load), and that its implementation would realise economic savings of between 12 and 24 million euro (between 4.80% and 9.72% of the 2010 total regional budget expenditure for HIV management) in the first year, with cumulated savings of between 48 and 145 million euro over the following five years. Organizational, ethical and equity impact did not indicate any significant differences. The study suggests that for specific categories of patients monotherapy may be an alternative to existing therapies. Its implementation would not result in higher operating costs, and would lead to a reduction in total expenditure.

Intraprocedural contrast-enhanced ultrasound (CEUS) in liver percutaneous radiofrequency ablation: clinical impact and health technology assessment

OBJECTIVES

To assess the clinical and the economic impacts of intraprocedural use of contrast-enhanced ultrasound (CEUS) in patients undergoing percutaneous radiofrequency ablation for small (<2.5 cm) hepatocellular carcinomas.

METHODS

One hundred and forty-eight hepatocellular carcinomas in 93 patients were treated by percutaneous radiofrequency ablation and immediate assessment by intraprocedural CEUS. Clinical impact, cost effectiveness, and budget, organisational and equity impacts were evaluated and compared with standard treatment without intraprocedural CEUS using the health technology assessment approach.

RESULTS

Intraprocedural CEUS detected incomplete ablation in 34/93 (36.5 %) patients, who underwent additional treatment during the same session. At 24-h, complete ablation was found in 88/93 (94.6 %) patients. Thus, a second session of treatment was spared in 29/93 (31.1 %) patients. Cost-effectiveness analysis revealed an advantage for the use of intraprocedural CEUS in comparison with standard treatment (4,639 vs 6,592) with a 21.9 % reduction of the costs to treat the whole sample. Cost per patient for complete treatment was <euro> 4,609 versus <euro> 5,872 respectively. The introduction of intraprocedural CEUS resulted in a low organisational impact, and in a positive impact on equity

CONCLUSIONS

Intraprocedural use of CEUS has a relevant clinical impact, reducing the number of re-treatments and the related costs per patient.

TEACHING POINTS

• CEUS allows to immediately asses the result of ablation. • Intraprocedural CEUS decreases the number of second ablative sessions. • Intraprocedural CEUS may reduce cost per patient for complete treatment. • Use of intraprocedural CEUS may reduce hospital budget. • Its introduction has low organisational impact, and relevant impact on equity.

Real-world economic burden of venous thromboembolism and antithrombotic prophylaxis in medical inpatients

INTRODUCTION

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in medical patients, and the economic burden of this disease is plausibly relevant as well. However, few data from real-world observations are available on this topic. Aim of our study was to assess the costs of VTE management and antithrombotic prophylaxis in patients hospitalized in Internal Medicine (IM) departments.

MATERIALS AND METHODS

The in-hospital paths of 160 patients with VTE (VTE group) and 160 patients receiving prophylaxis and without VTE (NO-VTE group) were retrospectively evaluated within 26IM units in Italy. The economic analysis was undertaken by applying a process analysis, the initial phase of the more comprehensive Activity Based Costing technique. Accordingly to this approach, only information closely linked to VTE or its prevention was registered.

RESULTS

The total median costs for VTE management were around four-times higher than those for prophylaxis (€ 1,348.68 vs € 373.03). Human resources were the most important cost-driver (55.5% and 65.7% in the VTE and NO-VTE groups), followed by instrumental (24.6% in VTE and 15.5% in NO-VTE) and haematologic tests (12.6% in VTE patients and 13.3% in controls). In the NO-VTE group the direct costs for prophylaxis accounted for 4.5% of total.

CONCLUSIONS

The real-world data of this study confirm the economic burden of in-hospital treatment of VTE, and the relatively low costs of thromboprophylaxis. A greater adherence to evidence-based protocols for VTE prevention could probably reduce the current financial burden of VTE on healthcare systems.

Pressure ulcers management: an economic evaluation

INTRODUCTION

Pressure ulcer management represents a growing problem for medical and social health care systems all over the world, particularly in European Union countries where the incidence of pressure ulcers in older persons (> 60 years of age) is predicted to rise.

OBJECTIVES

The aim of this study was to provide evidence for the lower impact on economic resources of using advanced dressings for the treatment of pressure ulcers with respect to conventional simple dressings.

METHODS

Two different models of analysis, derived from Activity Based Costing and Health Technology Assessment, were used to measure, over a 30-day period, the direct costs incurred by pressure ulcer treatment for community-residing patients receiving integrated home care.

RESULTS

Although the mean cost per home care visit was higher in the advanced dressings patient group than in the simple dressings patient one (E 22.31 versus E 16.03), analysis of the data revealed that the cost of using advanced dressings was lower due to fewer home care visits (22 versus 11).

CONCLUSION

The results underline the fact that decision-makers need to improve their understanding of the advantages of taking a long-term view with regards to the purchase and use of materials. This could produce considerable savings of resources in addition to improving treatment efficacy for the benefit of patients and the health care system.

A few simple rules governing hydrogenation of graphene dots

We investigated binding of hydrogen atoms to small polycyclic aromatic hydrocarbons (PAHs)--i.e., graphene dots with hydrogen-terminated edges--using density functional theory and correlated wavefunction techniques. We considered a number of PAHs with three to seven hexagonal rings and computed binding energies for most of the symmetry unique sites, along with the minimum energy paths for significant cases. The chosen PAHs are small enough to not present radical character at their edges, yet show a clear preference for adsorption at the edge sites which can be attributed to electronic effects. We show how the results, as obtained at different levels of theory, can be rationalized in detail with the help of a few simple concepts derivable from a tight-binding model of the π electrons.

[Effectiveness of the project "I don't smoke, and you?" against smoking in a secondary school in Italy]

"I don't smoke, and you?" is a project aimed at secondary school students and is part of a wider project called "Free from Smoke", implemented by the Lombardia Region and involving elementary and secondary school students. The project is a controlled non randomized study whose aim is to direct students toward a healthy and smoke-free way of living, by also involving parents and teachers. A total of 11,610 12 year-olds of both sexes were evaluated, 6392 of whom were enrolled in the program and 5218 of whom served as controls and only completed the questionnaire. Three years after the start of the program, a greater increase in the prevalence of smokers was found amongst the group of controls than amongst the enrolled group (108,3% vs +93.8%, p>0.001). The percentage of students who believe that smoking even a small number of cigarettes is harmful, increased in the enrolled group (+0.6%) while it diminished in controls (-2.1%). In addition, a strong association was found between receiving a weekly allowance and smoking habits. In conclusion, positive results were obtained as regards the prevalence of smokers and the perceived risk of smoking; however parents' attitude towards smoking and the availability of a weekly allowance were found to have a strong influence in students' smoking habits.

Heterotopic gastric mucosa in the upper esophagus: report of a case with a fistula

We report the case of a 36-year-old man with a patch of heterotopic gastric mucosa in the upper esophagus complicated by an esophageal fistula.

[Experimental model of infection of Helicobacter pylori in the mouse. A study of gastric damage caused by indomethacin]

INTRODUCTION

The action of non-steroidal anti-inflammatory drugs (NSAIDs) on the Helicobacter Pylori (Hp) infected mucosa is a matter of debate. Some authors consider them to cause additive iatrogeny whilst others attribute a purportedly protective action to them. The development of on experimental animal model could help clarify this phenomenon.

OBJECTIVES

1--To develop an animal model of Hp gastric infection. 2--To evaluate the aggressiveness of NSAIDs in this model.

MATERIALS AND METHODS

Male 6 month old BALC/C mice weighing 38 g were studied. Pylori Hp infection was ruled out. On three occasions, in the same week, 18 mice were inoculated intra-gastrically with 0.6 ml of Hp culture broth (brain-heart infusion) containing 1 x 10 8-1 x 10 9 CFU/ml. Another group of mice were inoculated with sterile saline. After two months the mice were killed and their stomachs studied. They were divided into groups: a) 6 Hp negative control mice. b) 8 Hp negative mice with prior intra-peritoneal injection of 25 mg/Kg indomethacin (24 hs.) c) 8 mice inoculated with Hp with indomethacin. d) 8 mice inoculated with Hp, without indomethacin. The stomachs were opened along the greater curvature and photographed macroscopically in order to map the necrotic area. The antrums were biopsied to test for urease and separate antrum and body specimens were send for staining with Warthin-Starry H & B and histopathology.

RESULTS

All the mice inoculated with Hp acquired the infection. The necrotic area was larger in Group B: 55.5 +/- 7.87 mm than in Group C: 15 +/- 1.82 mm P < 0.00019.

HISTOLOGY

Group A: normal mucosa. Group B: extensive coagulation necrosis and focal erosions. Group C: ulcers with inflammatory infiltrate and smaller necrotic area, presence of Hp on the surface epithelium. Group D: no ulcers, Hp present.

CONCLUSION

An animal model of Hp infection was successfully developed Hp infection could play a potentially protective role against indomethacin aggression in the mouse.

Sequential administration of temozolomide and fotemustine: depletion of O6-alkyl guanine-DNA transferase in blood lymphocytes and in tumours

BACKGROUND

The DNA repair protein O6-alkylguanine-DNA alkyl transferase (AT) mediates resistance to chloroethylnitrosoureas. Agents depleting AT such as DTIC and its new analogue temozolomide (TMZ) can reverse resistance to chloroethylnitrosoureas. We report the results of a dose finding study of TMZ in association with fotemustine.

PATIENTS AND METHODS

Twenty-four patients with metastatic melanoma or recurrent glioma were treated with escalating dose of oral or intravenous TMZ ranging from 300 to 700 mg/m2, divided over two days. Fotemustine 100 mg/m2 was given intravenously on day 2, 4 hours after TMZ. AT depletion was measured in peripheral blood mononuclear cells (PBMCs) and in selected cases in melanoma metastases and was compared to TMZ pharmacokinetics.

RESULTS

The maximum tolerated dose (MTD) of TMZ was 400 mg/m2 (200 mg/m2/d) when associated with fotemustine the 2nd day with myelosuppression as dose limiting toxicity. The decrease of AT level in PBMCs was progressive and reached 34% of pretreatment values on day 2. There was however wide interindividual variability. AT reduction was neither dose nor route dependent and did not appear to be related to TMZ systemic exposure (AUC). In the same patients, AT depletion in tumour did not correlate with the decrease of AT observed in PBMCs.

CONCLUSIONS

PBMCs may not be used as a surrogate of tumour for AT depletion. Further study should concentrate on the pharmacokinetic pharmacodynamic relationship in tumour to provide the basis for individually tailored therapy.

Mode of action of thiocoraline, a natural marine compound with anti-tumour activity

Thiocoraline, a new anticancer agent derived from the marine actinomycete Micromonospora marina, was found to induce profound perturbations of the cell cycle. On both LoVo and SW620 human colon cancer cell lines, thiocoraline caused an arrest in G1 phase of the cell cycle and a decrease in the rate of S phase progression towards G2/M phases, as assessed by using bromodeoxyuridine/DNA biparametric flow cytometric analysis. Thiocoraline does not inhibit DNA-topoisomerase II enzymes in vitro, nor does it induce DNA breakage in cells exposed to effective drug concentrations. The cell cycle effects observed after exposure to thiocoraline appear related to the inhibition of DNA replication. By using a primer extension assay it was found that thiocoraline inhibited DNA elongation by DNA polymerase alpha at concentrations that inhibited cell cycle progression and clonogenicity. These studies indicate that the new anticancer drug thiocoraline probably acts by inhibiting DNA polymerase alpha activity.

Effect of ecteinascidin-743 on the interaction between DNA binding proteins and DNA

Ecteinascidin-743 (ET-743) is a tetrahydroisoquinoline alkaloid isolated from Ecteinascidia turbinata, a tunicate growing in mangrove roots in Caribbean. It has been shown to bind in the minor groove of DNA forming covalent adducts by reaction of the N2 of guanine with the carbinolamine moiety. We investigated ET-743 ability to inhibit the binding of different transcription factors to their consensus sequences by using gel shift assays. We have selected three types of factors: (i) oncogene products such as MYC, c-MYB and Maf; (ii) transcriptional activators regulated during the cell cycle as E2F and SRF; and (iii) general transcription factors such as TATA binding protein (TBP), Sp1 and NF-Y. We observed no inhibition of the binding of Sp1, Maf, MYB and MYC. Inhibition of DNA binding was observed for TBP, E2F, SRF at ET-743 concentrations ranging from 50 to 300 microM. The inhibition of binding of NF-Y occurs at even lower concentrations (i.e. 10-30 microM) when the recombinant subunits of NF-Y are preincubated with the drug, indicating that the inhibition of NF-Y binding does not require previous ET-743 DNA binding. Since NF-Y is a trimer containing two subunits with high resemblance to histones H2B and H2A, we have investigated the effect of ET-743 on nucleosome reconstitution. ET-743 caused a decrease of the nucleosomal band at 100 nM, with the complete disappearance of the band at 3-10 microM. These data suggest that the mode of action of this novel anticancer drug is related to its ability to modify the interaction between some DNA binding proteins and DNA.

The antitumour activity of alkylating agents is not correlated with the levels of glutathione, glutathione transferase and O6-alkylguanine-DNA-alkyltransferase of human tumour xenografts. EORTC SPG and PAMM Groups

Twenty-three human xenografts, including five colon, five gastric, nine lung (three small cell lung cancer) and four breast carcinomas, were investigated for their sensitivity to nitrosoureas, dacarbazine (DTIC), cyclophosphamide (CTX) and cisplatin (DDP). In 12 cases, at least one of the drugs produced complete or partial remission, in 2, a minor regression was observed and in the other 9, treatment was ineffective. The level of sensitivity to each drug, using a score from 1 to 5, was correlated to three biochemical parameters reported to be involved in resistance to alkylating agents: glutathione (GSH), glutathione transferase (GST) and O6-alkylguanine-DNA-alkyltransferase (AGT). A wide variability was found in these parameters in the xenografts investigated. No correlation was found between any of the three parameters and sensitivity to the drugs used or between sensitivity to one drug and to any of the other drugs tested. These results illustrate the complexity of the question of resistance to alkylating agents and indicate that, at least in xenografts, the biochemical parameters examined are not predictive of response to alkylating agents.

Prevalence and etiology of gastroduodenal ulcer in HIV-positive patients: a comparative study of 497 symptomatic subjects evaluated by endoscopy

OBJECTIVE

In 497 HIV-positive (+) patients with upper digestive tract symptoms, 23 (5%) had gastroduodenal ulcers (GDU) at upper endoscopy.

METHODS

To establish the causes of GDU in this setting, 16 of these patients who had had comprehensive histological evaluation (group I) were compared with 20 HIV+ subjects with upper gastrointestinal symptoms but without ulcer (group II), and with 16 seronegative patients with GDU (group III). Eighty-one percent of group I subjects and 90% of group II patients had C3 AIDS. The presence of gastritis and Helicobacter pylori, fungi, mycobacteria, viruses (especially cytomegalovirus [CMV] and herpes simplex [HSV]), and parasites was determined in all three groups by histopathological and microbiological studies.

RESULTS

The prevalence of chronic active gastritis was 13/16 (81%) in group I, 12/20 (60%) in group II, and 15/16 (94%) in group III. It was associated with H. pylori in group III, and with opportunistic pathogens in groups I and II and with none in group III. H. pylori was detected in 5/16 patients (31%) in group I, in 12/20 (60%) in group II, and 11/16 (69%) in group III. Cytomegalovirus was histologically diagnosed in 8/16 patients (50%) in group I and in 1/20 (5%) in group II. This virus was the only factor shown to be significantly associated with GDU in these cases (p = 0.0046). Cryptosporidium was found in 2/16 (12.5%) patients in group I, in 1/20 (5%) in group II, and in none in group III. Differences between groups I and II were not statistically significant. No other organisms were observed in the three groups.

CONCLUSIONS

Gastroduodenal ulcers were infrequent in HIV+ subjects with upper digestive tract symptoms and CMV was the only organism significantly associated with GDU in HIV+ patients. Among HIV+ patients, H. pylori was an uncommon cause of ulcer. Among HIV+ subjects with ulcer, chronic active gastritis was more common than H. pylori and it was associated with other pathogens. Finally, HIV+ patients with GDU should have endoscopic biopsies to detect opportunistic infections, especially CMV, because H. pylori infection is uncommon.

[Acute low digestive hemorrhage in testicular choriocarcinoma]

We report a case in which acute intestinal hemorrhage was the initial manifestation in the evolution of choriocarcinoma of the testis. The diagnosis of bleeding was difficult and required laparotomy. Metastatic lesion of the small bowel should be considered a possible cause of intestinal bleeding in patients with testicular choriocarcinoma.

Effect of G:C-->A:T transition, potentially arising from O6-guanine alkylation, in the transcription regulation of c-fos serum response element

O6-meGs, if not repaired before cell undergo DNA synthesis, can cause erroneous pairing of thymine resulting in a G:C-->A:T transition, after the next DNA replication. It is known that the presence of O6-meG in promoter sequences inhibits the specific binding of transcription factors. Little is known on the effect of G:C-->A:T transitions on this binding. c-fos SRE was used as a model to study the effect of different G:C-->A:T transitions (at the positions -305, -306, -316, -319 and -320) in terms of SRE specific DNA-binding and functional ability to activate transcription of a reporter gene. The electromobility shift assay and a transient transfection assay were used. The G:C-->A:T transition at -320 caused 92% inhibition, while mutations at the positions -305, -306, -316 and -319 caused respectively 55, 43, 19 and 44% inhibition. The findings indicate that some G:C-->A:T transitions, potentially arising from O6-guanine methylation, can impair the regulation of c-fos transcription.

p21WAF1-derived peptides linked to an internalization peptide inhibit human cancer cell growth

We tested the ability of synthetic peptides derived from p21(WAF1), fused to the internalization peptide sequence derived from Antennapedia, to inhibit the growth of cancer cells in two human ovarian cancer cell lines expressing wild-type p53 or not. Two fused peptides corresponding to p21(WAF1) regions 17-33 and 63-77 inhibited cell growth in both cell lines while the same peptides without the internalization sequence were inactive. The fused peptides prevented growth at concentrations which inhibited cyclin-dependent kinase 2 and cdc2 activity, thus demonstrating that the peptides act by mimicking the action of p21(WAF1) on kinases. This study illustrates the potential pharmacological use of small peptides fused with the Antennapedia internalization sequence in proliferative disorders. The approach may be extended to other diseases in which cell penetration of a peptide may be of therapeutic benefit. More stable drug-like molecules with better pharmacological properties could be designed based on the results obtained with peptides.

Characterization of a protein recognizing minor groove binders-damaged DNA

By using electromobility shift assay (EMSA), we have identified a protein able to recognize the DNA only if it was previously reacted with minor groove binders. This protein binds with very high affinity AT containing DNA treated with minor groove binders such as distamycin A, Hoechst 33258 and 33342, CC-1065 and ethidium bromide minor groove intercalator, but not with major groove binders such as quinacrine mustard, cisplatin or melphalan, or with topoisomerase I inhibitor camptothecin or topoisomerase II inhibitor doxorubicin. This protein was found to be present in different extracts of human, murine and hamster cells, with the human protein which appears to have a molecular weight slightly lower than that of the other species. This protein was found to be expressed both in cancer and normal tissues. By using molecular ultrafiltration techniques as well as southwestern analysis it was estimated that the apparent molecular weight is close to 100 kDa. We can exclude an identity between this protein and other proteins, with a similar molecular weight previously reported to be involved in DNA damage recognition/repair, such as topoisomerase I, mismatch repair activities such as the prokaryotic MutS protein and its human homologue hMSH2 or proteins of the nucleotide excision repair system such as ERCC1, -2, -3 and -4.

Simultaneous immunoaffinity purification of O6-methyl, O6-ethyl-, O6-propyl- and O6-butylguanine and their analysis by gas chromatography/mass spectrometry

A sensitive and specific method has been developed for the simultaneous analysis of different O6-alkylguanines. The cross-reactivity of two different antibodies raised against O6-methylguanosine and O6-butylguanosine for a series of O6-alkylguanines was exploited for the immunoaffinity purification of biological samples before quantitative analysis by gas chromatography/mass spectrometry. The method can be applied to the detection of O6-alkylguanines in DNA and appears to be useful for studying chemical carcinogen mechanisms in animals and possibly for the detection of human exposure to alkylating agents.

Detection of O6-butyl- and O6-(4-hydroxybutyl)guanine in urothelial and hepatic DNA of rats given the bladder carcinogen N-nitrosobutyl(4-hydroxybutyl)amine

N-Nitrosobutyl(4-hydroxybutyl)amine (BBN) is a selective bladder carcinogen in rats. Its organ specificity may depend on several factors, including metabolic activation, DNA alkylation and repair within the target organ. Metabolic activation of BBN, which is asymmetrical, may result in butylating and 4-hydroxybutylating species. To test this view, BBN was administered as a single oral dose of 20 or 120 mg/rat or six doses of 20 mg/rat over 2 weeks. The animals given the single 120 mg dose were killed 3, 6 and 24 h after treatment. Rats given 20 mg or 6 x 20 mg BBN were killed 24 h after the last dose. DNA from liver and urothelial cells was hydrolyzed and analyzed for O6-butylguanine (O6-BuG) and O6-(4-hydroxybutyl)guanine [O6-(4-OH-Bu)G] as their pentafluorobenzyl-trimethylsilyl derivatives by high-resolution gas chromatography--negative ion chemical ionization mass spectrometry with selective ion recording after immunoaffinity extraction. Polyclonal antibodies raised against O6-(4-hydroxybutyl)-guanosine [O6-(4-OH-Bu)GR] were coupled to CNBr-activated Sepharose 4B. This was mixed with a gel coupled to antibodies raised against O6-BuG, already available in the laboratory, and the mixed gel was used for the one-step sample clean-up, enrichment and extraction of O6-(4-OH-Bu)G and O6-BuG from hydrolyzed DNA. O6-BuG in urothelial DNA of rats given a single dose of 120 mg BBN increased from 0.44 +/- 0.12 mumol/mol guanine (mean +/- SE) 3 h after treatment, to 17.9 +/- 7.23 mumol/mol guanine at 24 h. O6-(4-OH-Bu)G in the same tissue was 7.7 +/- 3.19 mumol/mol guanine 3 h after treatment and 12.2 +/- 7.01 mumol/mol guanine at 24 h. O6-BuG and O6-(4-OH-Bu)G were always lower in the liver than in urothelial cells. Twenty-four hours after a single dose of 20 mg BBN, urothelial O6-BuG was 5.41 +/- 1.73 mumol/mol guanine and did not accumulate after six doses of 20 mg/rat BBN, since it was 2.59 +/- 1.23 mumol/mol guanine 24 h after the last dose. O6-BuG in liver DNA was detectable after the single dose of 20 mg, but not after 6 x 20 mg/rat BBN. O6-(4-OH-Bu)G was not detected in either the bladder or the liver after 20 mg or after the six doses of BBN.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of O6-methylguanine on DNA damage and cytotoxicity of temozolomide in L1210 mouse leukemia sensitive and resistant to chloroethylnitrosoureas

Temozolomide is a new anticancer agent which in the early clinical investigation has shown promising antitumor activity. It decomposes spontaneously to the active metabolite of DTIC (MTIC). Temozolomide is more cytotoxic against L1210 than against a subline L1210/BCNU, resistant to chloroethylnitrosoureas. Using [methyl-3H] temozolomide we found that after 1 h exposure the amount of O6-methylguanine (O6mGua) was twice as high in L1210 than in L1210/BCNU whereas the amount of N7 mGua was approximately the same in the two cell lines. O6-alkylguanine DNA alkyltransferase (AT) levels were higher in L1210/BCNU than in L1210, supporting the view that the resistance to methyltriazenes is probably related to the efficient repair of O6mGua in L1210/BCNU. Exposure of L1210/BCNU cells to 0.4 mM O6mGua for 24 h resulted in a depletion of AT and in a higher temozolomide-induced cytotoxicity. In the sensitive cell line L1210, temozolomide activity was not potentiated by O6mGua pretreatment. Moreover, in L1210/BCNU, O6mGua increased DNA single-strand breaks caused by temozolomide, suggesting that O6-guanine alkylation induces an excision repair mechanism in cells depleted in AT.

DNA damage induced by alachlor after in vitro activation by rat hepatocytes

We investigated the ability of alachlor to cause DNA damage by measuring single-strand breaks (SSB) in DNA, after metabolic activation by freshly isolated rat hepatocytes. Incubation of different concentrations of alachlor with rat hepatocytes led to numerous metabolites. The majority, isolated and identified by GC-MS analysis, were products arising from reactions catalyzed by the P-450 monooxygenase system, arylamidase and flavin mixed-function oxidase/cytochrome P-450 monooxygenase. The results, using freshly isolated rat hepatocytes, showed that in these conditions several potentially DNA damaging metabolites were produced; this experimental condition was used to assess DNA damage induced by the mixture of alachlor and its metabolites. The alkaline elution technique showed that at 200 microM and more clearly at 400 microM there were some small fragments that eluted in the first fraction. This fragmentation was probably due to alachlor cytotoxicity. In addition to the small DNA fragments eluting in the first fraction there were other larger DNA fragments. These DNA-SSB were most evident at the alachlor concentration of 400 microM, but also at 200 microM and 100 microM, whereas at 10 microM the DNA elution rate appeared comparable to that of controls. The results suggest that some unstable and DNA-reactive metabolites might interact with DNA causing SSB and such interaction might be important in relation to the mechanism of alachlor-induced DNA damage. However, it may not be possible to clarify whether SSB are the result of direct DNA interaction of the compound or of secondary cellular processes after chemical treatment.

O6-methylguanine inhibits the binding of transcription factors to DNA

To study the effect of methylation of O6-guanine on the binding of cellular factors to different DNA sequences, modified oligonucleotides were constructed, in which O6-Methylguanine (O6-MeG) replaced some guanines. The DNA sequences utilized were: the region of the c-fos promoter containing the binding site for serum response factor (SRF); the region of the HIV LTR containing two binding sites for the transcription factor NF kappa B; the region of the HIV LTR containing three binding sites for the cellular factor sp1. After incubation of labeled oligonucleotides, either unmodified or containing O6-MeG, with nuclear extracts obtained from different cell lines, gel retardation assays indicated that the presence of O6-MeG resulted in inhibition of binding of cellular factors to DNA sequences located in the promoter regions of genes. This inhibition was not the same for all modified oligonucleotides but dependent on the position in which O6-MeG was located. The results obtained indicate that alkylation of O6-guanine affects the binding of transcription factors and thereby possibly the regulation of genes expression.

Determination of O6-butylguanine in DNA by immunoaffinity extraction/gas chromatography-mass spectrometry

A sensitive, specific, and rapid method for quantitating the minor adduct O6-butylguanine (O6BuG) in hydrolyzed DNA has been developed by combining immunoaffinity chromatography and high resolution gas chromatography-negative ion chemical ionization-mass spectrometry. Polyclonal antibodies raised against O6BuG were coupled to CNBr-activated Sepharose 4B and used for sample clean-up and extraction of the specific O6-alkylguanine. After addition of O6BuG and its deuterium labeled analogue (O6BuG-D7), used as internal standard, hydrolyzed DNA was applied on the immunoaffinity column and washed with water, and the immunoadsorbed butylated guanines were eluted with acetone/water cetome/water (95/5) before gas chromatographic derivatization. O6BuG and O6BuG-D7 were analyzed and quantitated by high resolution gas chromatography-negative ion chemical ionization-mass spectrometry as their pentafluorobenzyl-trimethylsilyl derivatives. Immunoaffinity column capacity and O6BuG recovery from this column were 1.53 nmol O6BuG/column and 62 +/- 5%, respectively. The method was applied to evaluate O6BuG levels in DNA butylated in vitro with 10 mM N-nitroso-Nr-butylurea or isolated from rats given an i.p. dose of 185 mg/kg N-nitroso-N-butylurea or N-nitrosodibutylamine. In the first case the level of modifications present in calf thymus DNA was 104 mumol O6BuG/mol guanine, and in the second case O6BuG in liver DNA was about 6 times higher after N-nitroso-N-butylurea (2.11 mumol O6BuG/mol guanine) than after N-nitrosodibutylamine (0.34 mumol O6BuG/mol guanine) treatment. These results indicate that O6BuG formed in vivo can be isolated and quantitated by this method, which may also be useful for studying DNA damage and repair mechanisms.

Alpha-oxidative metabolism of the bladder carcinogens N-nitrosobutyl(4-hydroxybutyl)amine and N-nitrosobutyl(3-carboxypropyl)amine within the rat isolated bladder

The most widely accepted metabolic pathway leading to the formation of reactive intermediates from nitrosamines involves enzymatic hydroxylation at the carbon atom alpha to the nitroso moiety. All subsequent steps are non-enzymatic reactions and the final result is the stoichiometric formation of a cationic product and molecular nitrogen. Thus the amount of molecular nitrogen evolved can be used as an indicator of alpha-hydroxylation. The use of doubly 15N-labelled nitrosamines and the detection of 15N2 by MS makes it simpler to measure the extent of alpha-hydroxylation. We have studied the alpha-oxidation of doubly 15N-labelled N-nitrosobutyl(4-hydroxybutyl)amine (BBN) and its metabolite N-nitrosobutyl(3-carboxypropyl)amine (BCPN), two potent urinary bladder carcinogens in animals, within the target organ. Various amounts of 15N-labelled BBN ranging from 0.1 to 5 mumol were incubated at 37 degrees C for 4 h in the isolated rat bladder and the formation of 15N2 was measured by GC-MS. 15N2 production was linear up to 1 mumol and represented approximately 0.1% of the substrate incubated. Time-course experiments showed that 15N2 production was linear over a 6 h incubation period, ranging from 2.16 +/- 0.05 to 4.55 +/- 0.33 nmol/mg urothelial cell protein. 15N-labelled BCPN (1-5 mumol) was also incubated within the rat isolated bladder. 15N2 production from BCPN was approximately 10 times less than that from BBN. The results indicate that, though to a lower extent, the target organ activates 15N-labelled BBN and BCPN through the alpha-hydroxylation pathway.

Pharmacokinetic profile and metabolism of N-nitrosobutyl-(4-hydroxybutyl)amine in rats

N-Nitrosodibutylamine and its omega-hydroxylated metabolite N-nitrosobutyl(4-hydroxybutyl)amine (NB4HBA) induce tumors in the urine bladder of different animal species through their common urinary metabolite N-nitrosobutyl(3-carboxypropyl)amine (NB3CPA), resulting from the oxidation of the alcoholic group of NB4HBA to a carboxylic group. NB4HBA disappearance from blood, the formation of its main metabolites, NB3CPA and NB4HBA-glucuronide (NB4HBA-G), and their urinary excretion, were investigated in rats after an i.v. dose of 1 mg/kg (5.7 mumol/kg). NB3CPA and NB4HBA-G formation was readily detectable 2 min after treatment and levels were still measurable at 120 and 30 min, respectively. The parent compound disappeared from blood 90 min after injection. The NB4HBA blood concentration-time profile was adequately described by a one-compartmental linear model. NB4HBA half-life was 8 min, total body clearance and renal clearance were 86.1 and 0.22 ml/min/kg, respectively. The 0-96-h urinary excretion of NB4HBA was 0.3% of the administered dose. NB3CPA half-life was 15 min; NB3CPA and NB4HBA-G urinary excretion were 36 and 11.7%, respectively, urinary excretion of known compounds accounting for less than 50%. After i.v. injection of NB3CPA equimolar to the NB4HBA dose, only 50% of unchanged compound was recovered in the urine and after NB4HBA-G, 41% of the administered dose was excreted unchanged, NB3CPA accounting for 10%. Thus NB3CPA and NB4HBA-G might undergo further biotransformation, suggesting that NB3CPA may not be the ultimate carcinogen responsible for urinary bladder tumor induction.

Development of an experimental model for studying bladder carcinogen metabolism using the isolated rat urinary bladder

The isolated rat urinary bladder was used to study this organ's capacity to metabolize chemical carcinogens. In our experimental conditions, the urinary bladder carcinogen N-nitrosobutyl(4-hydroxybutyl)amine was oxidized to N-nitrosobutyl(3-carboxypropyl)amine. A time-dependent increase was observed in the amount of N-nitrosobutyl(3-carboxypropyl)amine formed and simultaneous disappearance of N-nitrosobutyl(4-hydroxybutyl)amine added, indicating that the bladder can metabolize N-nitrosobutyl(4-hydroxybutyl)amine to the metabolite considered responsible for tumor induction in the urinary bladder of laboratory animals. At 15, 30, 60, and 120 min the percentages of N-nitrosobutyl(3-carboxypropyl)amine formed were 11, 22, 36, and 64%, respectively, and 62, 48, 37, and 26% of N-nitrosobutyl(4-hydroxybutyl)amine remained unchanged. When N-nitrosodibutylamine was introduced into the isolated urinary bladder and incubated for 120 min, its oxidized metabolites N-nitrosobutyl(4-hydroxybutyl)amine and N-nitrosobutyl(3-carboxypropyl)amine were formed, amounting to, respectively, 0.13 and 0.06% of the substrate added. The glucuronide of N-nitrosobutyl(4-hydroxybutyl)amine was incubated in the isolated rat urinary bladder both as a buffer and as a urine solution in order to detect cellular and urinary beta-glucuronidase activity. In both systems N-nitrosobutyl(4-hydroxybutyl)amine released was about 1% at 4 h and this percentage did not increase at 6 h. N-Nitrosobutyl(3-carboxypropyl)amine was detectable at 2 h and reached 0.2% of the substrate incubated at 6 h. The results indicate that the urinary bladder may play a role in activating bladder carcinogens.

Effect of butylated hydroxyanisole on in vitro and in vivo nitrosation of dibutylamine

The effect of the food additive butylated hydroxyanisole on the nitrosation of dibutylamine was studied in vitro and in vivo, in rats. At the highest concentration tested, butylated hydroxyanisole significantly inhibited the in vitro formation of N-nitrosodi-n-butylamine from dibutylamine and nitrite by 35%. This effect was not observed in animals given dibutylamine, NaNO2 and butylated hydroxyanisole by gavage in the same ratio that produced an effect in vitro. The oral administration of butylated hydroxyanisole to rats given 0.5% nitrate in the drinking water and dibutylamine (0.38 mmol/kg 3 times/day p.o.) was also with no effect, although the experimental model used proved suitable for studying the modulating effect on endogenous nitrosation of different chemicals such as ascorbic acid or potassium thiocyanate. The discrepancy between in vitro and in vivo results is discussed.