White paper on the promotion of an integrated risk assessment concept in European regulatory frameworks for chemicals

The vision of a sustainable and safe use of chemicals to protect human health, preserve the environment and maintain the ecosystem requires innovative and more holistic approaches to risk assessment (RA) in order to better inform decision making. Integrated risk assessment (IRA) has been proposed as a solution to current scientific, societal and policy needs. It is defined as the mutual exploitation of environmental risk assessment (ERA) for human health risk assessment (HHRA) and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process. Extrapolating between species which are relevant for HHRA and ERA requires a detailed understanding of pathways of toxicity/modes of action (MoA) for the various toxicological endpoints. Significant scientific advances, changes in chemical legislation, and increasing environmental consciousness have created a favourable scientific and regulatory environment to develop and promote the concept and vision of IRA. An initial proof of concept is needed to foster the incorporation of IRA approaches into different chemical sectorial regulations and demonstrate their reliability for regulatory purposes. More familiarity and confidence with IRA will ultimately contribute to an overall reduction in in vivo toxicity testing requirements. However, significant progress will only be made if long-term support for MoA-related research is secured. In the short term, further exchange and harmonization of RA terminology, models and methodologies across chemical categories and regulatory agencies will support these efforts. Since societal values, public perceptions and cultural factors are of increasing importance for the acceptance of risk analysis and successful implementation of risk mitigation measures, the integration of socio-economic analysis and socio-behavioural considerations into the risk analysis process may help to produce a more effective risk evaluation and consideration of the risks and benefits associated with the use of chemicals.

Simple convergent-nozzle aerosol injector for single-particle diffractive imaging with X-ray free-electron lasers

A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam.

Mikrowellen-Relaxation von Decylalkohol in Mischung mit unpolaren Flüssigkeiten

An reinem n-Decylalkohol, sowie seinen konzentrierten und verdünnten Lösungen in vier unpolaren Flüssigkeiten wurde zwischen 20 und 60°C die komplexe DK bei 9,4,19,5 und 34,8 GHz gemessen. Wenn man die Anteile abtrennt, die das Hauptabsorptionsgebiet bei diesen Frequenzen noch beiträgt, erhält man ein Mikrowellengebiet anomaler Dispersion, das allein von Prozessen mit Kurzzeitrelaxation herrührt. Dazu gehört eine Verteilung von Relaxationszeiten, die in erster Näherung durch zwei diskrete Werte zu beschreiben ist. Die so erhaltenen charakteristischen Daten — Dispersionsstufe, Relaxationszeit und Aktivierungsenergie — werden von sehr verdünnter Lösung, die nur Einzelmoleküle enthält, bis zur reinen Dipolflüssigkeit verfolgt und geben bei der Diskussion Hinweise auf die zugrundeliegenden molekularen Vorgänge. Danach ist die kürzeste Zeitkonstante der Eigenbewegung von polaren Molekülgruppen zuzuordnen, in verdünnter Lösung allein der OH-Gruppe. Die Dipolorientierung mit längerer Relaxationszeit dagegen hat quantitativ alle Kennzeichen, die von der rotatorischen Bewegung ganzer, starrer oder flexibler Moleküle bekannt sind. Zu ihr müssen bei konzentrierten Mischungen aber noch andere Strukturen beitragen als allein Monomere, wie aus dem Relaxationszeitspektrum des Einzelmoleküls in verdünnter Heptanlösung folgt. Bei Benzol treten durch eine spezifische Wechselwirkung mit der OH-Gruppe erhebliche Verschiebungen in der Relaxationszeit-Verteilung auf, die sich noch bei höheren Alkoholkonzentrationen bemerkbar machen.

Distinct eosinophil cytokine expression patterns in skin diseases - the possible existence of functionally different eosinophil subpopulations

BACKGROUND

The function of eosinophils has been attributed to host defense, immunomodulation, and fibrosis. Although eosinophils are found among infiltrating cells in a broad spectrum of skin diseases, their pathogenic role remains uncertain. This study aimed to analyze the cytokine expression by eosinophils in different skin diseases.

METHODS

Skin specimens from different skin diseases [allergic/reactive, infectious, autoimmune, and tumors/lymphomas (LY)] were stained by antibodies directed to eosinophil cationic protein, cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-5, IL-6, IL-10, IL-11, IL-13, IL-17, IL-25, IL-33, interferon-γ, transforming growth factor (TGF)-β, and thymic stromal lymphopoietin], eotaxins (CCL11, CCL24, and CCL26), metalloproteinase (MMP)-9 as well as extracellular matrix proteins (tenascin-C and procollagen-3) and then analyzed by laser scanning microscopy.

RESULTS

The number of eosinophils varied considerably in and between disease groups and did not correlate with the numbers of accompanying inflammatory cells. The expression of IL-5, IL-6, IL-11, TGF-β, CCL24, and MMP-9 by eosinophils significantly differed between disease groups. Eosinophils in tumors/LY predominantly expressed IL-6, TGF-β, and CCL24, but not IL-11. On the other hand, in autoimmune diseases, eosinophils largely contributed to MMP-9 production. IL-5-generating eosinophils were particularly obvious in allergic and infectious diseases.

CONCLUSION

In skin diseases, eosinophil expresses a broad spectrum of cytokines. The different cytokine expression patterns suggest distinct functional roles of eosinophils in these diseases that might be related to host defense, immunomodulation, fibrosis, and/or tumor development.

Does the frequency of HIV and STI testing among men who have sex with men in primary care adhere with Australian guidelines?

OBJECTIVES

Australian guidelines recommend annual testing for HIV and sexually transmitted infections (STIs) for all men who have sex with men (MSM) and 3-6 monthly testing for those at higher risk as defined by behavioural criteria. We assessed HIV/STI re-testing rates among MSM attending primary care clinics.

METHODS

We conducted a retrospective follow-up of HIV negative MSM tested for HIV or STIs (chlamydia or syphilis) at four primary care clinics in the 9-month period: April to December 2006. Re-testing rates for these infections were calculated over 18 months. Logistic regression was undertaken to identify predictors of guideline adherence.

RESULTS

Of the MSM requiring annual HIV testing according to the guidelines, the re-testing rates at 1 y were 35% (762/2163). Among the higher risk MSM, 6-monthly HIV re-testing rates were 15% (283/1862). Within the subgroup who reported 11 or more male sexual partners within the past 6 months, HIV re-testing rates within 6 months were 19%. Independent predictors of HIV re-testing within 6 months in higher-risk MSM were reporting 11 or more male sexual partners in the last 6 months (AOR 3.1, 95% CI 1.8 to 4.8); being born overseas (AOR 2.0, 95% CI 1.2 to 3.4); and previous HIV testing more than 12 months earlier (AOR 3.3, 95% CI 1.9 to 5.5).

CONCLUSION

There is poor adherence to national guidelines that recommend regular re-testing of MSM for STIs, particularly among those at higher risk who require more frequent testing. Clinical strategies are urgently needed to encourage more frequent HIV/STI testing among MSM, especially in the higher risk subgroup.

A randomized pilot study on the effectiveness and side-effect profiles of two doses of digoxin as fetocide when administered intraamniotically or intrafetally prior to second-trimester surgical abortion

BACKGROUND

Digoxin is commonly used to facilitate second-trimester surgical abortion despite limited data regarding its safety and effectiveness for this indication. We conducted a pilot study to determine the incidence of side effects after digoxin administration and whether effectiveness can be improved with variations in dose and technique.

STUDY DESIGN

Fifty-two women presenting for elective termination of pregnancy between 18 and 24 weeks' gestation were randomized to one of four digoxin treatment groups: 1.0 mg intraamniotic (1.0 IA), 1.0 mg intrafetal (1.0 IF), 1.5 mg intraamniotic (1.5 IA) or 1.5 mg intrafetal (1.5 IF). Ultrasound was used to assess for the presence of fetal cardiac activity prior to the abortion procedure. Data on the presence and severity of pain, nausea and other potential side effects were collected before digoxin injection, immediately following digoxin injection and on the day after digoxin injection.

RESULTS

Digoxin effectively induced fetal death in 87% of women. The failure rate did not vary by route of administration (IA or IF) and was not lowered by increasing the dose from 1.0 to 1.5 mg. IF injections induced fetal death more rapidly than IA injections. Digoxin administration did not result in increased pain or nausea.

CONCLUSIONS

IA or IF injection of digoxin is safe and effective for inducing fetal death prior to second-trimester surgical abortion. Doses greater than 1.0 mg may not be necessary.

Polyunsaturated fatty acids and cardiovascular disease: implications for nutrigenetics

Cardiovascular disease (CVD) arises as a result of genetic predisposition in the context of a disease-promoting environment. While several risk factors have been identified for CVD, such as elevated serum lipid levels and hypertension, most of the genes identified thus far do not appear to involve such 'conventional' risk factors. Moreover, the interactions between genes and environment, such as a diet high in certain fats, adds another level of complexity to CVD and renders identification of the underlying genetic factors even more difficult. Polyunsaturated fatty acids (PUFAs), such as the omega-6 and omega-3 fatty acids, which have multiple roles in membrane structure, lipid metabolism, blood clotting, blood pressure, and, in particular, inflammation, have been linked to the reduction in CVD. Linoleic (omega-6) and alpha-linolenic acid (omega-3) are essential fatty acids that can be converted into long-chain PUFAs, such as arachidonic acid (AA) and eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA), respectively. These long-chain PUFAs are metabolized by enzymatically catalyzed systems via cyclooxygenases and lipoxygenases. The 5-lipoxygenase (5-LO)/leukotriene (LT) biosynthesis pathway has been biochemically and genetically associated with CVD traits in mice and humans, particularly in the context of dietary AA and EPA/DHA. In this review, we summarize the biochemical metabolism of omega-3 and omega-6 PUFAs, evaluate the evidence for genetic and nutrigenetic contributions of 5-LO pathway genes to CVD, and discuss the potential of future studies that could identify other gene-dietary interactions between PUFAs and CVD traits.

Serum total 8-iso-prostaglandin F2α: A new and independent predictor of peripheral arterial disease

OBJECTIVE

Circulating 8-iso-prostaglandin F 2alpha (8-iso-PGF 2alpha ) has been proposed as new indicator of oxidative stress, which is involved in the pathophysiologic changes of atherosclerosis. We proposed to test the hypothesis that 8-iso-PGF 2alpha is an independent predictor of symptomatic peripheral arterial disease (PAD).

METHODS

A case-control study in 100 patients with symptomatic PAD and 100 control subjects matched for age, sex, and diabetes mellitus was conducted. Smokers and subjects using lipid-lowering drugs were excluded. Serum total 8-iso-PGF 2alpha was quantified with an enzyme immunoassay.

RESULTS

Median 8-iso-PGF 2alpha was higher in patients with PAD than in control subjects (63 vs 42 pg/mL; P = .001). Logistic regression with hypertension, body mass index, and creatinine, low-density lipoprotein (LDL) cholesterol, triglyceride, high-sensitivity C-reactive protein (hs-CRP), 8-iso-PGF 2alpha , and total homocysteine concentrations as independent variables and case-control status as dependent variable revealed significant odds ratios (OR) for hypertension (OR, 3.74; 95% confidence interval [CI], 1.85-7.53), low-density lipoprotein cholesterol (OR, 1.16, for an increment of 10 mg/dL; 95% CI, 1.07-1.27), high-sensitivity C-reactive protein (OR, 1.02, for an increment of 1 mg/L; 95% CI, 1.00-1.03), and 8-iso-PGF 2alpha (OR, 1.11, for an increment of 10 pg/mL; 95% CI, 1.03-1.20).

CONCLUSIONS

Serum total 8-iso-PGF 2alpha was an independent predictor of PAD in the population studied. This finding supports the hypothesis that 8-iso-PGF 2alpha is a risk marker for PAD. Our results indicate increased systemic oxidative stress in patients with PAD.

A randomized trial of nelfinavir, ritonavir, or delavirdine in combination with saquinavir-SGC and stavudine in treatment-experienced HIV-1-infected patients

PURPOSE

To evaluate the 24-week impact of saquinavir-enhancing antiretroviral therapy on viral replication in patients previously treated with nucleoside analogues with or without prior saquinavir hard-gel capsules (HGC).

METHOD

Patients were randomized in three groups to receive the following: Group 1-nelfinavir (750 mg tid), saquinavir soft-gel capsule (SGC) (800 mg tid), and stavudine (40 mg bid); Group II-ritonavir (400 mg bid), saquinavir-SGC (400 mg bid), and stavudine (40 mg bid); or Group III-delavirdine (400 mg tid), saquinavir-SGC (800 mg tid), and stavudine (40 mg bid). Viral loads, CD4 count, and safety were assessed over a 24-week period with an additional 6-month follow-up.

RESULTS

73 patients received randomized therapy; 14 of whom were SQV naïve, with a median baseline viral load of 3.6 log(10) and a CD4 count of 370 cells/mm(3). By 6 months, the median decreases in plasma viral loads were 0.26, 0.71, and 0.29 log(10) copies/mL for groups I, II, and III, respectively. The median increases in CD4 counts, for groups I, II, and III, were 52, 40, and 69 cells/mm(3) at 6 months, respectively. Changes in viral load and CD4 counts at 6 months and 1 year were not significantly different between the treatment groups. More patients discontinued therapy in the ritonavir arm (35%) for drug intolerance or toxicity compared to either the nelfinavir or delavirdine arms (15% and 5%, respectively). In a multivariate analysis, baseline viral load, younger age, and baseline saquinavir resistance were significantly associated with detectable viral load at 24 weeks.

CONCLUSION

The use of antiretroviral agents that pharmacokinetically boost saquinavir levels has a modest benefit in saquinavir-experienced patients.

Photochemical decontamination of red blood cell concentrates with the silicon phthalocyanine PC 4 and red light

Various approaches are being developed for virus inactivation of red blood cell concentrates (RBCC) in order to increase the safety of the blood supply. We have been studying the silicon phthalocyanine Pc 4 for this purpose, a photosensitizer activated with red light. Pc 4 targets the envelope of pathogenic viruses such as HIV. To protect RBC during the process two main approaches are used: (i) inclusion of quenchers of reactive oxygen species produced during the treatment. Tocopherol succinate was found to be most effective for this purpose; (ii) formulation of Pc 4, a lipophilic compound, in liposomes that reduce its binding to RBC but not to viruses. As a light source we used a light emitting diode array emitting at 670-680 nm. An efficient mixing device ensures homogenous light exposure during treatment of intact RBCC. Treatment of 50 ml RBCC with 5 microM Pc 4 and 18 J/cm(2) light results in the inactivation of > or = 5.5 log(10) HIV, > or = 6.3 log(10), VSV and > or = 5 log(10) of PRV and BVDV. The relative sensitivities of these viruses based on the slope of virus kill versus light dose are 1.0, 1.25, 1.5 and 1.9 for HIV, VSV, PRV and BVDV, respectively. To achieve the same level of virus inactivation in 350 ml RBCC, the light dose needed is 40 J/cm(2). HIV actively replicating in CEM cells is as sensitive as cell-free and HIV in latently infected cells is 3-4 times more sensitive. Parasites that can be transmitted by blood transfusion (P. falciparum and T. cruzi) are even more sensitive than viruses. Following treatment, RBCC can be stored for 28 days at 4 degrees C with haemolysis below 1%. Previous studies under less favourable conditions showed that baboon RBC circulated with an acceptable 24 hr recovery and half-life. Genetic toxicological studies of Pc 4 with or without light exposure (mutagenicity in bacteria, mammalian cells in vitro and clastogenicity in vivo) were negative. We conclude that a process using Pc 4 and red light can potentially reduce the risk of transmitting pathogens in RBCC.

Capturing the paradigm shift in HIV treatment: changing attitudes in the choice of combination antiretroviral drugs by high HIV caseload Australian GPs (1996-1997)

The use of combination antiretroviral therapy for HIV infection is a rapidly changing field. To assess the impact of recent studies on prescribing patterns, two surveys of 21 high HIV caseload Australian GPs were undertaken in June 1996 and June 1997 to plot changes in the choice of combination antiviral therapy. Of the 17 GPs who responded to the survey in each year, the number of HIV-infected patients seen at their practices were estimated to be 5,061 in 1996 and 5,912 in 1997. In 1996, 40% of their patients were estimated to be on antiretroviral therapy compared to 60% in 1997 (p < 0.05). In 1996, most GPs preferred using dual combination therapy (59%); whereas in 1997, triple combination therapy was preferred (82%). Between 1996 and 1997, there was a significant change by high caseload Australian GPs in the choice of antiretroviral drugs with many combinations being preferred prior to presentation of efficacy data for those combinations, or recommendation through national guidelines.

Superior mesenteric artery syndrome after segmental instrumentation: a biomechanical analysis

Superior mesenteric artery (SMA) syndrome is a rare complication that occurs after correction of scoliosis. A review of the literature suggests that the incidence of this syndrome may be decreasing, as methods for the correction of scoliosis have improved. We present the first report of SMA syndrome that occurred after segmental 'derotational' instrumentation. Computerized axial tomography was helpful in suggesting the diagnosis of this condition. The risk factors and pathophysiology of SMA syndrome are reviewed with respect to the biomechanical effects of casting and Harrington and segmental instrumentation systems on the spine. Attention to the three-dimensional nature of the scoliotic deformity, particularly in the sagittal plane, may help to predict those at risk for the development of this potentially fatal syndrome.

Does cesarean section decrease the incidence of major birth trauma?

OBJECTIVE

To determine whether the increase in frequency of cesarean section is associated with a decreased incidence of major birth trauma.

STUDY DESIGN

A retrospective cohort study was performed evaluating all neonatal cases of major birth trauma from January 1989 to December 1994. Major birth trauma was defined as peripheral plexus or nerve injuries, fractures, or lacerations. The data were grouped into two mutually exclusive periods (January 1989 to December 1990 vs January 1991 to December 1994) in which a significant difference in the cesarean section rate was known.

RESULTS

Of 17,957 deliveries during the period, 141 cases of birth trauma occurred. One hundred thirty-seven of the 141 medical records were available for review, and 116 were classified as having had major birth trauma and were included in the study. The overall incidence of major birth trauma was 6.5/1000 deliveries. During the two-year period (January 1989 to December 1990), 18.3% of deliveries were by cesarean section and the major birth trauma rate was 8.4/1000 deliveries. During the following 4 years, the cesarean section rate was 22.3% and the major birth trauma rate was 5.3/1000 deliveries. Significant differences in the birth trauma chi(2) = 6.12, p = 0.013) and cesarean section (chi(2) = 40.80, p < 0.001) rates were observed. Controlling for the mode of delivery lessened the association between time period and birth trauma incidence (chi(2)MH = 3.28, p = 0.07). A significant decrease in the occurrence of major birth trauma in neonates delivered by cesarean section in the later period was discovered (relative risk = 0.46, 95% confidence interval 0.22 to 0.97). This decrease appeared to be mediated by a decrease in total lacerations between the periods (chi(2) = 11.76, p < 0.001), because the rates of other types of major birth trauma did not differ in neonates delivered by cesarean section or the vaginal route.

CONCLUSIONS

With a 4% increase in rate of cesarean section at our institution, a significant decrease in the occurrence of major birth trauma was observed. This finding cannot be explained by a decreased risk of neonatal trauma in patients delivering vaginally, but rather by a decreased risk of neonatal trauma at cesarean section during the latter period.

Particulate matter less than 10 microns (PM10) and fine particles less than 2.5 microns (PM2.5): relationships between indoor, outdoor and personal concentrations

Among 17 homes in Switzerland, the relationship between indoor and outdoor levels for particulate matter less than 10 microns (PM10), particulate matter less than 2.5 microns (PM2.5) and NO2 was investigated. In 10 homes, the inhabitants also participated in conducting personal measurements. All homes were naturally ventilated. In homes without any indoor sources and where human activity was low, PM10 I/O ratios amounted to approximately 0.7. Of the indoor sources, smoking had the highest influence on I/O ratios (> 1.8). In homes not containing any apparent source, 'human activity' was an important factor accounting for high indoor levels. However, this factor is difficult to quantify. Personal exposure was in most cases higher than the indoor and the corresponding home outdoor levels. For NO2, gas-cooking was found to have the strongest influence on elevated I/O ratios (> 1.2) whilst for other homes, the I/O ratio was less than 1.