Hexavalent chromium and isocyanate exposures during military aircraft painting under crossflow ventilation

Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers (“hosemen”). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 µg/m³, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m³, and 7 out of 12 exceeded the threshold limit value of 10 µg/m³, with means 38 µg/m³ for sprayers and 8.3 µg/m³ for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/m³ for hosemen. Total reactive isocyanate group—the total of monomer and oligomer as NCO group mass—showed 6 of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 µg/m³, with means 50.9 µg/m³ for sprayers and 7.29 µg/m³ for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m³/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m³/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re-circulations, turbulence, and fugitive emissions, while wasting energy. Smoke releases showing more effective ventilation here than in other aircraft painting facilities carries technical feasibility relevance.     

A study to assess the plaque inhibitory action of a newly formulated triclosan toothpaste

BACKGROUND/AIMS: Triclosan containing toothpastes have been noted for their potential to inhibit plaque and gingival inflammation. The aim of this study was to determine whether a toothpaste containing triclosan and an enhanced fluoride system would inhibit de novo plaque formation beyond that of a non-triclosan, conventional fluoride toothpaste. METHODS: This study used a 4-day plaque regrowth model in which 24 volunteers used toothpaste rinses as the only form of oral hygiene. Following a prophylaxis and a single brushing with the toothpastes, 2x daily rinsing with toothpaste slurries was used over the following 96 h. RESULTS: After 24 h, there was no difference in plaque area between the triclosan paste and its control paste. After 96 h, a reduction in plaque score of 5% was noted for the test toothpaste compared to the control paste which was statistically significant (p=0.028). For plaque area this reduction was increased to 16%, which was also significant (p=0.006). CONCLUSIONS: These findings would appear to warrant further investigation into the potential value of the paste in inhibiting both plaque and gingivitis.     

Influence of TNF-α and biomechanical stress on matrix metalloproteinases and lysyl oxidases expressions in human knee synovial fibroblasts

Purpose

It was reported that not only ACL but also the synovium may be the major regulator of matrix metalloproteinases (MMPs) in synovial fluids after ACL injury. In order to further confirm whether synovium is capable of regulating the microenvironment in the process of ACL injury, the complicated microenvironment of joint cavity after ACL injury was mimicked and the combined effects of mechanical injury and inflammatory factor [tumour necrosis factor-α (TNF-α)] on expressions of lysyl oxidases (LOXs) and MMPs in synovial fibroblasts derived from normal human synovium were studied.

Methods

Human normal knee joint synovial fibroblasts were stimulated for 1–6 h with mechanical stretch and inflammatory factor (TNF-α). Total RNA was harvested, reverse transcribed and assessed by real-time polymerase chain reaction for the expression of LOXs and MMP-1, 2, 3 messenger RNAs. MMP-2 activity was assayed from the collected culture media samples using zymography.

Results

Compared to control group, our results showed that 6 % physiological stretch increased MMP-2 and LOXs (except LOXL-3), decreased MMP-1 and MMP-3; injurious stretch (12 %) decreased LOXs (except LOXL-2)and increased MMP-1, 2 and 3; the combination of injurious stretch and TNF-α decreased LOXs and increased MMP-1, 2 and 3 in synovial fibroblasts in a synergistical manner.

Conclusion

This study demonstrated that combination of mechanical injury and inflammatory factors up-regulated the expressions of MMPs and down-regulated the expressions of LOXs in synovial fibroblasts, eventually alter the balance of tissue healing. Thus, synovium may be involved in regulating the microenvironment of joint cavity. Based on the mechanism, early interventions to inhibit the production of MMPs or promote the production of LOXs in the synovial fibroblasts should be performed to facilitate the healing of tissue.     

Screening for autism in extremely preterm infants: problems in interpretation

Aim The aim of this article was to report the prevalence of, and risk factors for, positive autism screens using the Modified Checklist for Autism in Toddlers (M‐CHAT) in children born extremely preterm in England. Method All children born at not more than 26 weeks' gestational age in England during 2006 were recruited to the EPICure‐2 study. At 2 years of age, postal questionnaires incorporating the M‐CHAT and additional developmental questions were sent to the parents of each survivor (n=1031; 499 male, 532 female), of which 523 (266 male, 257 female; 51%) were returned completed. Results The prevalence of positive M‐CHAT screens in this extremely preterm population was 41% (216/523; 130 male; 86 female). Severe bronchopulmonary dysplasia, administration of postnatal steroids, late‐onset bacteraemia, and being male were statistically significantly associated with a positive screen. Coexisting disabilities were present in 320 (62%) children. Of 200 children without disability, 16.5% screened positive. In contrast, 63 (95.5%) of those with severe motor impairment (odds ratio 42; 95% confidence interval [CI] 12.9–135) and 175 (55.9%) of those with cognitive impairment (odds ratio 5.3; CI 3.5–8) screened positive. All children with a significant vision or hearing impairment screened positive. Interpretation The prevalence of positive M‐CHAT screens in extremely preterm children is high, especially in children with neurodevelopmental impairment. Positive screens should be interpreted in the light of other neurodevelopmental sequelae in clinical practice to avoid false‐positive referrals.     

Characteristics of children with cerebral palsy in the ORACLE children study

Aims We have identified an excess of children with cerebral palsy (CP) born to women who received antibiotic treatment for spontaneous preterm labour (SPL). This nested study investigated the profile of impairment among children with CP in the ORACLE Children Study (OCS), and contrasted outcomes with those in 4Child, a population CP registry. Method The study group comprised 167 children aged from 7 to 10 years (100 males, 67 females) with CP from the OCS, who were subdivided into a preterm rupture of membranes (PROM) group (87 children) and an SPL group (80 children). The OCS sought follow‐up information regarding the health and behaviour of surviving children at 7 years of age in the UK using a parent‐report postal questionnaire. Families provided further information to define wider aspects of function and were offered a physiotherapy assessment. Results The prevalence of CP was higher among children in the OCS than among those in 4Child (standardized morbidity ratios: SPL group, 3.12 [95% confidence interval CI 2.47–3.87); PROM group: 1.56 (CI 1.24–1.92)]. The proportion of children with CP born after 32 weeks of gestation was higher in in the SPL group (73%) than in the PROM group (30%); the prevalence of CP was higher in the SPL group than in the PROM group or 4Child. Children with CP in the OCS tended to have similar distributions of neuroimpairment as children in 4Child, but motor impairment and associated vision and hearing problems were found to be less severe. Interpretation The pattern of CP in both the PROM and the SPL groups was similar, but functional outcomes were milder, compared with children with CP in the general population. However, in these groups the risk of CP was increased independently of gestational age. This is consistent with findings that ongoing inflammatory damage can cause CP.     

Differential BMP-1 expression in injured anterior cruciate ligament and medial collateral ligament fibroblasts induced by TGF-β1

目的 观察在转化生长因子-β1(transforming growth factor betal,TGF-β1)作用下,损伤的前交叉韧带(anterior cruciate ligament,ACL)和内侧副韧带(medial collateral ligament,MCL)中骨形态发生蛋白-1(bone morphogenetic protein-1,BMP-1)基因的表达,找出TGF-31、BMP-1之间的关系,揭示机械损伤后ACL和MCL细胞中BMP-1的表达差异.方法 采用反转录PCR(RT-PCR)和实时荧光定量PCR方法检测1、5、50 ng/ml TGF-β1处理后2h受损的ACL和MCL细胞中BMP-1的表达以及5 ng/ml TGF-β1作用2、6、12、24h受损的ACL和MCL细胞中BMP-1的表达;Western blot检测5 ng/mlTGF-β1处理48 h后受损的ACL和MCL细胞中BMP-1的表达.结果 受损的ACL和MCL细胞中BMP-1的基因表达比正常状态下偏高,并随着TGF-β1浓度的增大而增高,在MCL中的增高程度比在ACL中高出近1倍(P＜0.05);与正常组相比,在5 ng/ml TGF-β1处理24h后,ACL细胞中BMP-1的表达在24h达到最高比例(约为6.1倍),而在MCL中12h达到最高比例(约为9.84倍,P＜0.05).5 ng/ml TGF-β1处理48 h后BMP-1蛋白也明显上调,与无TGF-β1处理的对照组相比,ACL细胞中BMP-1上调2.32倍,MCL细胞中BMP-1上调3.84倍(P＜0.05).结论 TGF-β1刺激BMP-1的变化可能直接影响到细胞外基质中活性赖氨酰氧化酶的表达,对损伤ACL和MCL的修复有极其重要的参考价值和临床意义.     

European online postgraduate educational programme in neonatology—the way forward?

The provision of specialist postgraduate training is increasingly challenging for the acute medical specialties. There are often small numbers of trainees and tutors in any one centre, and service commitments may limit attendance at educational activities. Online learning can provide high-quality education to trainees from large geographical areas. We report the outcomes of an experimental educational project which provided an online postgraduate programme in neonatology. Ninety trainees from 14 countries, primarily European, participated. Six educational modules in neonatal topics were delivered over a 1-year period, within a “Virtual Learning Environment”. Trainees were divided into multi-national groups; two online tutors supported each group. Analysis of online activity demonstrated that active participation was high initially (100%) but gradually declined to 46% in the final module; tutor participation followed a similar pattern. Eighty-six trainees were contactable at the end of the programme, and 67 (78%) completed an evaluation questionnaire. Of these, 92% reported that participation had “added value” to their training, attributable to the high-quality curriculum, the educational resources, collaborative networking and the sharing of best practice. Eleven (79%) tutors completed the questionnaire, with all reporting that participation was of educational value. The main limiting factor for trainees and tutors was insufficient time. This project confirms that multi-national online education in neonatology is feasible and transferable, but for this approach to be viable formal accreditation and protected time for both trainees and tutors are required.     

Adolescents' beliefs about their parents' human papillomavirus vaccination decisions

A significant minority of parents are concerned that human papillomavirus vaccination will affect sexual behaviour. We explored this issue with 162 adolescent girls. Most (between 90 and 92%) did not perceive a connection between parental consent to vaccination and parental authorisation for sexual activity, but a small percentage believed that vaccination consent implied that they were old enough to have sex (8%), or that it was okay for them to be sexually active (10%). The findings are broadly reassuring, but highlight the need for vaccination information materials to clarify why the vaccine is administered before sexual debut.     

Minimally invasive technology in the management of breast disease

Minimally invasive surgery is gaining popularity around the world because it achieves the same or even superior results when compared to standard surgery but with less morbidity. Minimally invasive breast surgery is a broad concept encompassing new developments in the field of breast surgery that work on this minimally invasive principle. In this regard, breast-conserving surgery and sentinel lymph node biopsy are good illustrations of this concept. There are three major areas of progress in the minimally invasive management of breast disease. First, percutaneous excisional devices are now available that can replace the surgical excision of breast mass lesions. Second, various ablative treatments are capable of destroying breast cancers in situ instead of surgical excision. Third, mammary ductoscopy provides a new approach to the investigation of mammary duct pathology. Clinical experience and potential applications of these new technologies are reviewed.