Comparison of distribution and activity of nanoparticles with short interfering DNA (Dbait) in various living systems

Introducing small DNA molecules (Dbait) impairs the repair of damaged chromosomes and provides a new method for enhancing the efficiency of radiotherapy in radio-resistant tumors. The radiosensitizing activity is dependent upon the efficient delivery of Dbait molecules into the tumor cells. Different strategies have been compared, to improve this key step. We developed a pipeline of assays to select the most efficient nanoparticles and administration protocols before preclinical assays: (i) molecular analyses of complexes formed with Dbait molecules, (ii) cellular tests for Dbait uptake and activity, (iii) live zebrafish embryo confocal microscopy monitoring for in vivo distribution and biological activity of the nanoparticles and (iv) tumor growth and survival measurement on mice with xenografted tumors. Two classes of nanoparticles were compared, polycationic polymers with linear or branched polyethylenimine (PEI) and covalently attached cholesterol (coDbait). The most efficient Dbait transfection was observed with linear PEI complexes, in vitro and in vivo. Doses of coDbait ten-fold higher than PEI/Dbait nanoparticles, and pretreatment with chloroquine, were required to obtain the same antitumoral effect on xenografted melanoma. However, with a 22-fold lower ‘efficacy dose/toxicity dose' ratio as compared with Dbait/PEI, coDbait was selected for clinical trials.

[Five year survival for lung cancer patients managed in general hospitals]

INTRODUCTION

In 2000 the College of Pulmonologists of General Hospitals undertook an epidemiological study (KBP-2000-CPHG) enrolling all new cases of histologically confirmed lung cancer managed in general hospitals. This paper reports the five year survival in these cases.

METHODS

Vital status was available for 5447 out of 5667 patients included in the original study. The effect of different prognostic factors on mortality was assessed.

RESULTS

At 5 years 567 patients (10.4%) were still alive. Median survival for the 4880 (89.6%) deceased patients was 7 months. Univariate analysis identified age, smoking history, performance status, histological type and disease stage (TMN classification) as determinants of survival. For non-small cell lung cancer (n=4885) multivariate analysis identified five predictive factors for mortality - age, gender histological type, performance status and stage.

CONCLUSIONS

Five year survival in lung cancer continues to be poor. As the risk factors for poor outcome at the time of diagnosis are not modifiable and pending the results of screening studies reduction in mortality must rest on primary prevention.

[Evaluation of antibiotic prophylaxis for hip and knee replacement: a multicentered study in Aquitaine public and private hospitals (SouthWestern France)]

OBJECTIVE

The aim of the study was to estimate the prescription and administration of antibioprophylaxis for hip and knee replacement in Aquitaine (SouthWestern France).

METHODS

In 2003, "Social Security" medical experts performed a descriptive and retrospective study on a sample of scheduled surgical operations in all the Aquitaine public and private hospitals. Antibioprophylaxis, protocols, and practice were assessed by studying the patients' medical files. The analysis was made on adjusted numbers to take into account the size of every institution.

RESULTS

In 51 hospitals, 58.8% of antibioprophylaxis protocols followed French guidelines. The sample corresponded to an adjusted number of 9,651 patients. Antibiopropylaxis was prescribed for 99.3% of patients, the course of antibioprophylaxis followed guidelines for 77.4% of the patients, the choice of the molecule and the dosage in 85.4% of the cases. Interval between antibiotic injection and surgical section was the main criterion of nonconformity (56.3%); it was under30 minutes for 43.7% of cephalosporin injections. In the post-operative period, administration complied with the medical prescription for 76.4% of the patients and dosage was adapted for 60.0% of the patients. According to the studied variables, 3 to 23.5% of data was missing in the medical files.

CONCLUSION

If the quality of care and practice must be improved, it is mandatory to implement written and confirmed antibioprophylaxis protocols, to better document medical files, to insure an improved coordination among professionals before, during, and after surgery.

Sequential two-line strategy for stage IV non-small-cell lung cancer: docetaxel-cisplatin versus vinorelbine-cisplatin followed by cross-over to single-agent docetaxel or vinorelbine at progression: final results of a randomised phase II study

BACKGROUND

This phase II trial compared docetaxel-cisplatin (DC) with vinorelbine-cisplatin (VC), both as first-line therapy followed by cross-over at progression to single-agent vinorelbine or docetaxel in advanced non-small-cell lung cancer (NSCLC).

METHODS

Overall, 115 patients received DC (docetaxel 75 mg/m(2) and cisplatin 100 mg/m(2) both on day 1, every 3 weeks, arm A1) and 118 VC (vinorelbine 30 mg/m(2)/week on days 1 and 8 and cisplatin 100 mg/m(2) on day 1, every 3 weeks, arm B1) for six cycles, and subsequently maintained by monotherapy with docetaxel (A1) or vinorelbine (B1) with cross-over on disease progression to vinorelbine 30 mg/m(2) days 1 and 8 (A2), or docetaxel 100 mg/m(2), day 1, both every 3 weeks (B2). The primary end point was overall response rate (ORR).

RESULTS

Patient characteristics were balanced; median follow-up was 8.8 months. First-line response rate was 33.9% with DC and 26.3% with VC (P=0.20). In arms A1 and B1, respectively: duration of response was similar (8.2 versus 8.4 months); median time to progression was 5 months in both; median survival was 8 versus 9 months (P=0.38); 1-, 2- and 3-year survival was 36% versus 35%, 17% versus 10% and 13% versus 6% (P not significant). However, with a low number of long-term survivors, statistical significance was not reached. Overall, almost half of the patients crossed over to second-line therapy; there were no response with vinorelbine and 6 (11.2%) partial responses with docetaxel. Considering the safety profile, the occurrence of febrile neutropenia was 9.6% with DC and 26.3% with VC. Treatment-related mortality was 2.5% with DC and 8.5% with VC.

CONCLUSIONS

The trend in favour of the DC arm in ORR, even though statistical significance was not reached, is consistent with previous reports. This study suggests an activity of first-line DC in advanced NSCLC, and that second-line vinorelbine does not provide additional clinical benefit. As already shown in other studies, the use of DC in first-line should provide a better percentage of long-term survivors, despite the absence of efficacy of the second-line in our study.

Concurrent sexual partnerships and HIV prevalence in five urban communities of sub-Saharan Africa

OBJECTIVE

To estimate parameters of concurrent sexual partnerships in five urban populations in sub-Saharan Africa and to assess their association with levels of HIV infection and other sexually transmitted infections (STI).

METHODS

Data were obtained from a multicentre study of factors which determine the differences in rate of spread of HIV in five African cities. Consenting participants were interviewed on sexual behaviour and at four of the five sites also provided a blood and a urine sample for testing for HIV and other STI. Data on sexual behaviour included the number of partnerships in the 12 months preceding the interview as well as the dates of the start and end of each partnership. Summary indices of concurrent sexual partnerships -- some of which were taken from the literature, while others were newly developed -- were computed for each city and compared to HIV and STI prevalence rates.

RESULTS

A total of 1819 adults aged 15--49 years were interviewed in Dakar (Senegal), 2116 in Cotonou (Benin), 2089 in Yaoundé (Cameroon), 1889 in Kisumu (Kenya) and 1730 in Ndola (Zambia). Prevalence rates of HIV infection were 3.4% for Cotonou, 5.9% for Yaoundé, 25.9% for Kisumu and 28.4% for Ndola, and around 1% for Dakar. The estimated fraction of sexual partnerships that were concurrent at the time of interview (index k) was relatively high in Yaoundé (0.98), intermediate in Kisumu (0.44) and Cotonou (0.33) and low in Ndola (0.26) and in Dakar (0.18). An individual indicator of concurrency (iic) was developed which depends neither on the number of partners nor on the length of the partnerships and estimates the individual propensity to keep (positive values) or to dissolve (negative values) on-going partnership before engaging in another one. This measure iic did not discriminate between cities with high HIV infection levels and cities with low HIV infection levels. In addition, iic did not differ significantly between HIV-infected and uninfected people in the four cities where data on HIV status were collected.

CONCLUSION

We could not find evidence that concurrent sexual partnerships were a major determinant of the rate of spread of HIV in five cities in sub-Saharan Africa. HIV epidemics are the result of many factors, behavioural as well as biological, of which concurrent sexual partnerships are only one.

Using aggregate geographic data to proxy individual socioeconomic status: does size matter?

OBJECTIVES

This study assessed whether aggregate-level measures of socioeconomic status (SES) are less biased as proxies for individual-level measures if the unit of geographic aggregation is small in size and population.

METHODS

National Health Interview Survey and census data were used to replicate analyses that identified the degree to which aggregate proxies of individual SES bias interpretations of the effects of SES on health.

RESULTS

Ordinary least squares regressions on self-perceived health showed that the coefficients for income and education measured at the tract and block group levels were larger than those at the individual level but smaller than those estimated by Geronimus et al. at the zip code level.

CONCLUSIONS

Researchers should be cautious about use of proxy measurement of individual SES even if proxies are calculated from small geographic units.

[Small cell carcinoma of the esophagus. Report of five cases with review of the literature]

Small-cell carcinomas of the esophagus are a rare and aggressive tumors with early widespread dissemination. Despite the use of different therapeutic modalities, the prognosis remains poor. Between 1993 and 1995, 5 patients with small-cell carcinoma of the esophagus were treated at René-Gauducheau Center, representing 2.8% of all esophageal malignancies diagnosed during this period. Three patients presented with limited disease while 2 patients had distant metastases at the time of diagnosis. Primary treatment consisted of polychemotherapy in all patients and a complete response was observed in three cases. These 3 patients had received subsequent radiotherapy, and endoesophageal brachytherapy in 2 cases. In this article, we report our experience of patients with this tumor and attempt to make comparisons with the cases published in the literature, regarding location, symptomatology, histopathologic diagnosis and treatment of this tumor. We conclude that the optimum treatment seems to be the same as for small-cell carcinoma of the lung, a multidrug combination chemotherapy regimen used alone or with sequential radiation.