Biological monitoring of occupational exposure to polycyclic aromatic hydrocarbons in prebake smelting

In 1984, the International Agency for Research on Cancer determined that working in the primary aluminium production process was associated with exposure to certain polycyclic aromatic hydrocarbons (PAHs) that are probably carcinogenic to humans. Key sources of PAH exposure within the occupational environment of a prebake aluminium smelter are processes associated with use of coal-tar pitch. Despite the potential for exposure via inhalation, ingestion and dermal adsorption, to date occupational exposure limits exist only for airborne contaminants. This study, based at a prebake aluminium smelter in Queensland, Australia, compares exposures of workers who came in contact with PAHs from coal-tar pitch in the smelter’s anode plant (n = 69) and cell-reconstruction area (n = 28), and a non-production control group (n = 17). Literature relevant to PAH exposures in industry and methods of monitoring and assessing occupational hazards associated with these compounds are reviewed, and methods relevant to PAH exposure are discussed in the context of the study site. The study utilises air monitoring of PAHs to quantify exposure via the inhalation route and biological monitoring of 1-hydroxypyrene (1-OHP) in urine of workers to assess total body burden from all routes of entry. Exposures determined for similar exposure groups, sampled over three years, are compared with published occupational PAH exposure limits and/or guidelines. Results of paired personal air monitoring samples and samples collected for 1-OHP in urine monitoring do not correlate. Predictive ability of the benzene-soluble fraction (BSF) in personal air monitoring in relation to the 1-OHP levels in urine is poor (adjusted R2 < 1%) even after adjustment for potential confounders of smoking status and use of personal protective equipment. For static air BSF levels in the anode plant, the median was 0.023 mg/m3 (range 0.002–0.250), almost twice as high as in the cell-reconstruction area (median = 0.013 mg/m3, range 0.003–0.154). In contrast, median BSF personal exposure in the anode plant was 0.036 mg/m3 (range 0.003–0.563), significantly lower than the median measured in the reconstruction area (0.054 mg/m3, range 0.003–0.371) (p = 0.041). The observation that median 1-OHP levels in urine were significantly higher in the anode plant than in the reconstruction area (6.62 µmol/mol creatinine, range 0.09–33.44 and 0.17 µmol/mol creatinine, range 0.001–2.47, respectively) parallels the static air measurements of BSF rather than the personal air monitoring results (p < 0.001). Results of air measurements and biological monitoring show that tasks associated with paste mixing and anode forming in the forming area of the anode plant resulted in higher PAH exposure than tasks in the non-forming areas; median 1-OHP levels in urine from workers in the forming area (14.20 µmol/mol creatinine, range 2.02–33.44) were almost four times higher than those obtained from workers in the non-forming area (4.11 µmol/mol creatinine, range 0.09–26.99; p < 0.001). Results justify use of biological monitoring as an important adjunct to existing measures of PAH exposure in the aluminium industry. Although monitoring of 1-OHP in urine may not be an accurate measure of biological effect on an individual, it is a better indicator of total PAH exposure than BSF in air. In January 2005, interim study results prompted a plant management decision to modify control measures to reduce skin exposure. Comparison of 1-OHP in urine from workers pre- and post-modifications showed substantial downward trends. Exposure via the dermal route was identified as a contributor to overall dose. Reduction in 1-OHP urine concentrations achieved by reducing skin exposure demonstrate the importance of exposure via this alternative pathway. Finally, control measures are recommended to ameliorate risk associated with PAH exposure in the primary aluminium production process, and suggestions for future research include development of methods capable of more specifically monitoring carcinogenic constituents of PAH mixtures, such as benzo[a]pyrene.

Vitamin D intake needed to maintain target serum 25-Hydroxyvitamin D concentrations in participants with low sun exposure and dark skin pigmentation is substantially higher than current recommendations

Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake. Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7-8 wk in the fall, winter, spring, and summer in Davis, CA [38.5° N, 121.7° W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R^sup 2^ = 0.55; P < 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, ~20 min/d, ~18% body surface area (BSA) exposed] and high (80th percentile, ~90 min/d, ~35% BSA exposed) sun exposure, assuming an intake of 200 IU/d (5 ug/d). Predicted serum 25(OH)D concentrations for AA individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D ≥75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 IU/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 IU/d year-round.

Workers’ UV exposure and the subsequent impact on skin

Introduction: Excessive exposure to ultraviolet (UV) radiation from sunlight is a causative factor in the development of skin damage and skin cancer. Little research has been undertaken into assessing the sun exposure linking to skin damage inside buildings or behind window glass. This project directly addressed this issue by aiming to assess the role that UV exposure has on skin damage for indoor workers and drivers. Methods: Measurements of personal UV exposure using UV sensitive polymer dosimeters were undertaken of 41 indoor workers and 3 professional drivers. Physical measurements of skin characteristics including skin pigmentation and UV induced skin photoaging were also determined. In addition, demographic information along with phenotypic characteristics, sun exposure and sun protection practice history, and history of skin damage were assessed through a questionnaire. Results: Indoor workers typically received low doses of UV radiation. However, one driver received a high dose (13J/cm2 UVA and 4.99 MED UVB on the arm). Age and years residing in Australia had a positive correlation with UV induced skin pigmentation. The number of major sunburns before 18 years was a risk factor for skin damage in adults. Those participants with fair skin, non-black hair and blue/green /blue-grey eye were more likely to have skin damage related to sun exposure. Conclusions: A person’s age, years residing in Australia, numbers of major sunburn, skin colour, hair colour and eye colour are important factors associated with the development of sun-related skin damage in workers. ‘Real World’ implications: 1. The number of major sunburns before 18 years was a risk factor for skin damage in adults. This clearly confirms the importance of early prevention. To protect the skin from extensive sun exposure for your generation should have significance for further prevention of skin damage. 2. It is unsurprising that age and years residing in Australia were associated with skin damage related UV radiation. Therefore, the general public should reinforce their sun protective measures and check skin regularly. 3. Drivers should take sun protective measures during their working hours between sunrise and sunset.

Pre-clinical evaluation of amphiphilic silicone oligomers for scar remediation

The formation of hypertrophic scars is a frequent outcome of wound repair and often requires further therapy with treatments such as silicone gel sheets (SGS; Perkins et al., 1983). Although widely used, knowledge regarding SGS and their mechanism of action on hypertrophic scars is limited. Furthermore, SGS require consistent application for at least twelve hours a day for up to twelve consecutive months, beginning as soon as wound reepithelialisation has occurred. Preliminary research at QUT has shown that some species of silicone present in SGS have the ability to permeate into collagen gel skin mimetics upon exposure. An analogue of these species, GP226, was found to decrease both collagen synthesis and the total amount of collagen present following exposure to cultures of cells derived from hypertrophic scars. This silicone of interest was a crude mixture of silicone species, which resolved into five fractions of different molecular weight. These five fractions were found to have differing effects on collagen synthesis and cell viability following exposure to fibroblasts derived from hypertrophic scars (HSF), keloid scars (KF) and normal skin (nHSF and nKF). The research performed herein continues to further assess the potential of GP226 and its fractions for scar remediation by determining in more detail its effects on HSF, KF, nHSF, nKF and human keratinocytes (HK) in terms of cell viability and proliferation at various time points. Through these studies it was revealed that Fraction IV was the most active fraction as it induced a reduction in cell viability and proliferation most similar to that observed with GP226. Cells undergoing apoptosis were also detected in HSF cultures exposed to GP226 and Fraction IV using the Tunel assay (Roche). These investigations were difficult to pursue further as the fractionation process used for GP226 was labour-intensive and time inefficient. Therefore a number of silicones with similar structure to Fraction IV were synthesised and screened for their effect following application to HSF and nHSF. PDMS7-g-PEG7, a silicone-PEG copolymer of low molecular weight and low hydrophilic-lipophilic balance factor, was found to be the most effective at reducing cell proliferation and inducing apoptosis in cultures of HSF, nHSF and HK. Further studies investigated gene expression through microarray and superarray techniques and demonstrated that many genes are differentially expressed in HSF following treatment with GP226, Fraction IV and PDMS7-g-PEG7. In brief, it was demonstrated that genes for TGFβ1 and TNF are not differentially regulated while genes for AIFM2, IL8, NSMAF, SMAD7, TRAF3 and IGF2R show increased expression (>1.8 fold change) following treatment with PDMS7-g-PEG7. In addition, genes for αSMA, TRAF2, COL1A1 and COL3A1 have decreased expression (>-1.8 fold change) following treatment with GP226, Fraction IV and PDMS7-g-PEG7. The data obtained suggest that many different pathways related to apoptosis and collagen synthesis are affected in HSF following exposure to PDMS7-g-PEG7. The significance is that silicone-PEG copolymers, such as GP226, Fraction IV and PDMS7-g-PEG7, could potentially be a non-invasive substitute to apoptosis-inducing chemical agents that are currently used as scar treatments. It is anticipated that these findings will ultimately contribute to the development of a novel scar therapy with faster action and improved outcomes for patients suffering from hypertrophic scars.

Utility of an alternative bicycle commute route of lower proximity to motorised traffic in decreasing exposure to ultra-fine particles, respiratory symptoms and airway inflammation - a structured exposure experiment

Background: Bicycle commuting in an urban environment of high air pollution is known as a potential health risk, especially for susceptible individuals. While risk management strategies aimed to reduce motorised traffic emissions exposure have been suggested, limited studies have assessed the utility of such strategies in real-world circumstances. Objectives: The potential of reducing exposure to ultrafine particles (UFP; < 0.1 µm) during bicycle commuting by lowering interaction with motorised traffic was investigated with real-time air pollution and acute inflammatory measurements in healthy individuals using their typical, and an alternative to their typical, bicycle commute route. Methods: Thirty-five healthy adults (mean ± SD: age = 39 ± 11 yr; 29% female) each completed two return trips of their typical route (HIGH) and a pre-determined altered route of lower interaction with motorised traffic (LOW; determined by the proportion of on-road cycle paths). Particle number concentration (PNC) and diameter (PD) were monitored in real-time in-commute. Acute inflammatory indices of respiratory symptom incidence, lung function and spontaneous sputum (for inflammatory cell analyses) were collected immediately pre-commute, and one and three hours post-commute. Results: LOW resulted in a significant reduction in mean PNC (1.91 x e4 ± 0.93 x e4 ppcc vs. 2.95 x e4 ± 1.50 x e4 ppcc; p ≤ 0.001). Besides incidence of in-commute offensive odour detection (42 vs. 56 %; p = 0.019), incidence of dust and soot observation (33 vs. 47 %; p = 0.038) and nasopharyngeal irritation (31 vs. 41 %; p = 0.007), acute inflammatory indices were not significantly associated to in-commute PNC, nor were these indices reduced with LOW compared to HIGH. Conclusions: Exposure to PNC, and the incidence of offensive odour and nasopharyngeal irritation, can be significantly reduced when utilising a strategy of lowering interaction with motorised traffic whilst bicycle commuting, which may bring important benefits for both healthy and susceptible individuals.

Effects of air pollution exposure on adult bicycle commuters : an investigation of respiratory health, motorised traffic proximity and the utility of commute re-routing

Bicycle commuting has the potential to be an effective contributing solution to address some of modern society’s biggest issues, including cardiovascular disease, anthropogenic climate change and urban traffic congestion. However, individuals shifting from a passive to an active commute mode may be increasing their potential for air pollution exposure and the associated health risk. This project, consisting of three studies, was designed to investigate the health effects of bicycle commuters in relation to air pollution exposure, in a major city in Australia (Brisbane). The aims of the three studies were to: 1) examine the relationship of in-commute air pollution exposure perception, symptoms and risk management; 2) assess the efficacy of commute re-routing as a risk management strategy by determining the exposure potential profile of ultrafine particles along commute route alternatives of low and high proximity to motorised traffic; and, 3) evaluate the feasibility of implementing commute re-routing as a risk management strategy by monitoring ultrafine particle exposure and consequential physiological response from using commute route alternatives based on real-world circumstances; 3) investigate the potential of reducing exposure to ultrafine particles (UFP; < 0.1 µm) during bicycle commuting by lowering proximity to motorised traffic with real-time air pollution and acute inflammatory measurements in healthy individuals using their typical, and an alternative to their typical, bicycle commute route. The methods of the three studies included: 1) a questionnaire-based investigation with regular bicycle commuters in Brisbane, Australia. Participants (n = 153; age = 41 ± 11 yr; 28% female) reported the characteristics of their typical bicycle commute, along with exposure perception and acute respiratory symptoms, and amenability for using a respirator or re-routing their commute as risk management strategies; 2) inhaled particle counts measured along popular pre-identified bicycle commute route alterations of low (LOW) and high (HIGH) motorised traffic to the same inner-city destination at peak commute traffic times. During commute, real-time particle number concentration (PNC; mostly in the UFP range) and particle diameter (PD), heart and respiratory rate, geographical location, and meteorological variables were measured. To determine inhaled particle counts, ventilation rate was calculated from heart-rate-ventilation associations, produced from periodic exercise testing; 3) thirty-five healthy adults (mean ± SD: age = 39 ± 11 yr; 29% female) completed two return trips of their typical route (HIGH) and a pre-determined altered route of lower proximity to motorised traffic (LOW; determined by the proportion of on-road cycle paths). Particle number concentration (PNC) and diameter (PD) were monitored in real-time in-commute. Acute inflammatory indices of respiratory symptom incidence, lung function and spontaneous sputum (for inflammatory cell analyses) were collected immediately pre-commute, and one and three hours post-commute. The main results of the three studies are that: 1) healthy individuals reported a higher incidence of specific acute respiratory symptoms in- and post- (compared to pre-) commute (p < 0.05). The incidence of specific acute respiratory symptoms was significantly higher for participants with respiratory disorder history compared to healthy participants (p < 0.05). The incidence of in-commute offensive odour detection, and the perception of in-commute air pollution exposure, was significantly lower for participants with smoking history compared to healthy participants (p < 0.05). Females reported significantly higher incidence of in-commute air pollution exposure perception and other specific acute respiratory symptoms, and were more amenable to commute re-routing, compared to males (p < 0.05). Healthy individuals have indicated a higher incidence of acute respiratory symptoms in- and post- (compared to pre-) bicycle commuting, with female gender and respiratory disorder history indicating a comparably-higher susceptibility; 2) total mean PNC of LOW (compared to HIGH) was reduced (1.56 x e4 ± 0.38 x e4 versus 3.06 x e4 ± 0.53 x e4 ppcc; p = 0.012). Total estimated ventilation rate did not vary significantly between LOW and HIGH (43 ± 5 versus 46 ± 9 L•min; p = 0.136); however, due to total mean PNC, accumulated inhaled particle counts were 48% lower in LOW, compared to HIGH (7.6 x e8 ± 1.5 x e8 versus 14.6 x e8 ± 1.8 x e8; p = 0.003); 3) LOW resulted in a significant reduction in mean PNC (1.91 x e4 ± 0.93 x e4 ppcc vs. 2.95 x e4 ± 1.50 x e4 ppcc; p ≤ 0.001). Commute distance and duration were not significantly different between LOW and HIGH (12.8 ± 7.1 vs. 12.0 ± 6.9 km and 44 ± 17 vs. 42 ± 17 mins, respectively). Besides incidence of in-commute offensive odour detection (42 vs. 56 %; p = 0.019), incidence of dust and soot observation (33 vs. 47 %; p = 0.038) and nasopharyngeal irritation (31 vs. 41 %; p = 0.007), acute inflammatory indices were not significantly associated to in-commute PNC, nor were these indices reduced with LOW compared to HIGH. The main conclusions of the three studies are that: 1) the perception of air pollution exposure levels and the amenability to adopt exposure risk management strategies where applicable will aid the general population in shifting from passive, motorised transport modes to bicycle commuting; 2) for bicycle commuting at peak morning commute times, inhaled particle counts and therefore cardiopulmonary health risk may be substantially reduced by decreasing exposure to motorised traffic, which should be considered by both bicycle commuters and urban planners; 3) exposure to PNC, and the incidence of offensive odour and nasopharyngeal irritation, can be significantly reduced when utilising a strategy of lowering proximity to motorised traffic whilst bicycle commuting, without significantly increasing commute distance or duration, which may bring important benefits for both healthy and susceptible individuals. In summary, the findings from this project suggests that bicycle commuters can significantly lower their exposure to ultrafine particle emissions by varying their commute route to reduce proximity to motorised traffic and associated combustion emissions without necessarily affecting their time of commute. While the health endpoints assessed with healthy individuals were not indicative of acute health detriment, individuals with pre-disposing physiological-susceptibility may benefit considerably from this risk management strategy – a necessary research focus with the contemporary increased popularity of both promotion and participation in bicycle commuting.

Modelling risk at low exposure railway level crossings : supporting an argument for low-cost level crossing warning devices with lower levels of safety integrity

This paper describes a risk model for estimating the likelihood of collisions at low-exposure railway level crossings, demonstrating the effect that differences in safety integrity can have on the likelihood of a collision. The model facilitates the comparison of safety benefits between level crossings with passive controls (stop or give-way signs) and level crossings that have been hypothetically upgraded with conventional or low-cost warning devices. The scenario presented illustrates how treatment of a cross-section of level crossings with low cost devices can provide a greater safety benefit compared to treatment with conventional warning devices for the same budget.

Treatment plan complexity metrics for predicting IMRT pre-treatment quality assurance results

The planning of IMRT treatments requires a compromise between dose conformity (complexity) and deliverability. This study investigates established and novel treatment complexity metrics for 122 IMRT beams from prostate treatment plans. The Treatment and Dose Assessor software was used to extract the necessary data from exported treatment plan files and calculate the metrics. For most of the metrics, there was strong overlap between the calculated values for plans that passed and failed their quality assurance (QA) tests. However, statistically significant variation between plans that passed and failed QA measurements was found for the established modulation index and for a novel metric describing the proportion of small apertures in each beam. The ‘small aperture score’ provided threshold values which successfully distinguished deliverable treatment plans from plans that did not pass QA, with a low false negative rate.

Ultrafine particle emission of waste incinerators and comparison to the exposure of urban citizens

On the basis of the growing interest on the impact of airborne particles on human exposure as well as the strong debate in Western countries on the emissions of waste incinerators, this work reviewed existing literature to: (i) show the emission factors of ultrafine particles (particles with a diameter less than 100 nm) of waste incinerators, and; (ii) assess the contribution of waste incinerators in terms of ultrafine particles to exposure and dose of people living in the surrounding areas of the plants in order to estimate eventual risks. The review identified only a limited number of studies measuring ultrafine particle emissions, and in general they report low particle number concentrations at the stack (the median value was equal to 5.5×103 part cm-3), in most cases higher than the outdoor background value. The lowest emissions were achieved by utilization of the bag-house filter which has an overall number-based filtration efficiency higher than 99%. Referring to reference case, the corresponding emission factor is equal to 9.1×1012 part min-1, that is lower than one single high-duty vehicle. Since the higher particle number concentrations found in the most contributing microenvironments to the exposure (indoor home, transportation, urban outdoor), the contribution of the waste incinerators to the daily dose can be considered as negligible.

Low temperature exposure of root system and inflorescence affected flowering and fruit set in 'Chardonnay' grapevines (Vitis vinifera)

The mechanisms by which low temperature affects flowering and fruit set of grapevines are poorly understood, as is the specific response of the grapevine root system and inflorescence to low temperature effects that reduce fruit set. This study aimed to determine the responses of the root system and inflorescence of the grapevine 'Chardonnay' to low temperature (10 degrees C) during flowering, and considered the possible mechanisms of low temperature effects on those parts. Temperature treatments of 10 degrees C or 20 degrees C were imposed to potted 'Chardonnay' grapevines in a glasshouse for up to two weeks during the early stages of flowering. When the root system alone was exposed to 10 degrees C (with the rest of the plant at 20 degrees C) during flowering, the number of attached berries and percentage fruit set were significantly reduced by 50 % than when the root system alone was exposed to 20 degrees C. Whereas, exposure of the inflorescence alone to 10 degrees C (with the rest of the plant at 20 degrees C) delayed flowering, allowed rachis to grow longer, and increased both the number of attached berries (from 22 to 62 per vine) and fruit set (from 8 % to, 20 %), than when the inflorescence alone was exposed to 20 degrees C. This study will enhance our understanding of the possible mechanisms of low temperature effects on grapevine fruit set and productivity.

Individualized immunosuppression after renal transplantation in childhood

Pediatric renal transplantation (TX) has evolved greatly during the past few decades, and today TX is considered the standard care for children with end-stage renal disease. In Finland, 191 children had received renal transplants by October 2007, and 42% of them have already reached adulthood. Improvements in treatment of end-stage renal disease, surgical techniques, intensive care medicine, and in immunosuppressive therapy have paved the way to the current highly successful outcomes of pediatric transplantation. In children, the transplanted graft should last for decades, and normal growth and development should be guaranteed. These objectives set considerable requirements in optimizing and fine-tuning the post-operative therapy. Careful optimization of immunosuppressive therapy is crucial in protecting the graft against rejection, but also in protecting the patient against adverse effects of the medication. In the present study, the results of a retrospective investigation into individualized dosing of immunosuppresive medication, based on pharmacokinetic profiles, therapeutic drug monitoring, graft function and histology studies, and glucocorticoid biological activity determinations, are reported. Subgroups of a total of 178 patients, who received renal transplants in 1988 2006 were included in the study. The mean age at TX was 6.5 years, and approximately 26% of the patients were <2 years of age. The most common diagnosis leading to renal TX was congenital nephrosis of the Finnish type (NPHS1). Pediatric patients in Finland receive standard triple immunosuppression consisting of cyclosporine A (CsA), methylprednisolone (MP) and azathioprine (AZA) after renal TX. Optimal dosing of these agents is important to prevent rejections and preserve graft function in one hand, and to avoid the potentially serious adverse effects on the other hand. CsA has a narrow therapeutic window and individually variable pharmacokinetics. Therapeutic monitoring of CsA is, therefore, mandatory. Traditionally, CsA monitoring has been based on pre-dose trough levels (C0), but recent pharmacokinetic and clinical studies have revealed that the immunosuppressive effect may be related to diurnal CsA exposure and blood CsA concentration 0-4 hours after dosing. The two-hour post-dose concentration (C2) has proved a reliable surrogate marker of CsA exposure. Individual starting doses of CsA were analyzed in 65 patients. A recommended dose based on a pre-TX pharmacokinetic study was calculated for each patient by the pre-TX protocol. The predicted dose was clearly higher in the youngest children than in the older ones (22.9±10.4 and 10.5±5.1 mg/kg/d in patients <2 and >8 years of age, respectively). The actually administered oral doses of CsA were collected for three weeks after TX and compared to the pharmacokinetically predicted dose. After the TX, dosing of CsA was adjusted according to clinical parameters and blood CsA trough concentration. The pharmacokinetically predicted dose and patient age were the two significant parameters explaining post-TX doses of CsA. Accordingly, young children received significantly higher oral doses of CsA than the older ones. The correlation to the actually administered doses after TX was best in those patients, who had a predicted dose clearly higher or lower (> ±25%) than the average in their age-group. Due to the great individual variation in pharmacokinetics standardized dosing of CsA (based on body mass or surface area) may not be adequate. Pre-Tx profiles are helpful in determining suitable initial CsA doses. CsA monitoring based on trough and C2 concentrations was analyzed in 47 patients, who received renal transplants in 2001 2006. C0, C2 and experienced acute rejections were collected during the post-TX hospitalization, and also three months after TX when the first protocol core biopsy was obtained. The patients who remained rejection free had slightly higher C2 concentrations, especially very early after TX. However, after the first two weeks also the trough level was higher in the rejection-free patients than in those with acute rejections. Three months after TX the trough level was higher in patients with normal histology than in those with rejection changes in the routine biopsy. Monitoring of both the trough level and C2 may thus be warranted to guarantee sufficient peak concentration and baseline immunosuppression on one hand and to avoid over-exposure on the other hand. Controlling of rejection in the early months after transplantation is crucial as it may contribute to the development of long-term allograft nephropathy. Recently, it has become evident that immunoactivation fulfilling the histological criteria of acute rejection is possible in a well functioning graft with no clinical sings or laboratory perturbations. The influence of treatment of subclinical rejection, diagnosed in 3-month protocol biopsy, to graft function and histology 18 months after TX was analyzed in 22 patients and compared to 35 historical control patients. The incidence of subclinical rejection at three months was 43%, and the patients received a standard rejection treatment (a course of increased MP) and/or increased baseline immunosuppression, depending on the severity of rejection and graft function. Glomerular filtration rate (GFR) at 18 months was significantly better in the patients who were screened and treated for subclinical rejection in comparison to the historical patients (86.7±22.5 vs. 67.9±31.9 ml/min/1.73m2, respectively). The improvement was most remarkable in the youngest (<2 years) age group (94.1±11.0 vs. 67.9±26.8 ml/min/1.73m2). Histological findings of chronic allograft nephropathy were also more common in the historical patients in the 18-month protocol biopsy. All pediatric renal TX patients receive MP as a part of the baseline immunosuppression. Although the maintenance dose of MP is very low in the majority of the patients, the well-known steroid-related adverse affects are not uncommon. It has been shown in a previous study in Finnish pediatric TX patients that steroid exposure, measured as area under concentration-time curve (AUC), rather than the dose correlates with the adverse effects. In the present study, MP AUC was measured in sixteen stable maintenance patients, and a correlation with excess weight gain during 12 months after TX as well as with height deficit was found. A novel bioassay measuring the activation of glucocorticoid receptor dependent transcription cascade was also employed to assess the biological effect of MP. Glucocorticoid bioactivity was found to be related to the adverse effects, although the relationship was not as apparent as that with serum MP concentration. The findings in this study support individualized monitoring and adjustment of immunosuppression based on pharmacokinetics, graft function and histology. Pharmacokinetic profiles are helpful in estimating drug exposure and thus identifying the patients who might be at risk for excessive or insufficient immunosuppression. Individualized doses and monitoring of blood concentrations should definitely be employed with CsA, but possibly also with steroids. As an alternative to complete steroid withdrawal, individualized dosing based on drug exposure monitoring might help in avoiding the adverse effects. Early screening and treatment of subclinical immunoactivation is beneficial as it improves the prospects of good long-term graft function.

Pre-clinical toxicity & immunobiological evaluation of DNA rabies vaccine & combination rabies vaccine in rhesus monkeys (Macaca mulatta)

Background & objectives: Pre-clinical toxicology evaluation of biotechnology products is a challenge to the toxicologist. The present investigation is an attempt to evaluate the safety profile of the first indigenously developed recombinant DNA anti-rabies vaccine DRV (100 mu g)] and combination rabies vaccine CRV (100 mu g DRV and 1.25 IU of cell culture-derived inactivated rabies virus vaccine)], which are intended for clinical use by intramuscular route in Rhesus monkeys. Methods: As per the regulatory requirements, the study was designed for acute (single dose - 14 days), sub-chronic (repeat dose - 28 days) and chronic (intended clinical dose - 120 days) toxicity tests using three dose levels, viz. therapeutic, average (2x therapeutic dose) and highest dose (10 x therapeutic dose) exposure in monkeys. The selection of the model i.e. monkey was based on affinity and rapid higher antibody response during the efficacy studies. An attempt was made to evaluate all parameters which included physical, physiological, clinical, haematological and histopathological profiles of all target organs, as well as Tiers I, II, III immunotoxicity parameters. Results: In acute toxicity there was no mortality in spite of exposing the monkeys to 10XDRV. In sub chronic and chronic toxicity studies there were no abnormalities in physical, physiological, neurological, clinical parameters, after administration of test compound in intended and 10 times of clinical dosage schedule of DRV and CRV under the experimental conditions. Clinical chemistry, haematology, organ weights and histopathology studies were essentially unremarkable except the presence of residual DNA in femtogram level at site of injection in animal which received 10X DRV in chronic toxicity study. No Observational Adverse Effects Level (NOAEL) of DRV is 1000 ug/dose (10 times of therapeutic dose) if administered on 0, 4, 7, 14, 28th day. Interpretation & conclusions: The information generated by this study not only draws attention to the need for national and international regulatory agencies in formulating guidelines for pre-clinical safety evaluation of biotech products but also facilitates the development of biopharmaceuticals as safe potential therapeutic agents.

Cytotoxicity of TiO2 nanoparticles towards freshwater sediment microorganisms at low exposure concentrations

There is a persistent need to assess the effects of TiO2 nanoparticles on the aquatic ecosystem owing to their increasing usage in consumer products and risk of environmental release. The current study is focused on TiO2 nanoparticle-induced acute toxicity at sub-ppm level (<= 1 ppm) on the three different freshwater sediment bacterial isolates and their consortium under two different irradiation (visible light and dark) conditions. The consortium of the bacterial isolates was found to be less affected by the exposure to the nanoparticles compared to the individual cells. The oxidative stress contributed considerably towards the cytotoxicity under both light and dark conditions. A statistically significant increase in membrane permeability was noted under the dark conditions as compared to the light conditions. The optical and fluorescence microscopic images showed aggregation and chain formation of the bacterial cells, when exposed to the nanoparticles. The electron microscopic (SEM, TEM) observations suggested considerable damage of cells and bio-uptake of nanoparticles. The exopolysaccrides (EPS) production and biofilm formation were noted to increase in the presence of the nanoparticles, and expression of the key genes involved in biofilm formation was studied by RT-PCR. (C) 2014 Elsevier Inc. All rights reserved.