Defining occupational and consumer exposure limits for enzyme protein respiratory allergens under REACH

A wide range of substances have been recognized as sensitizing, either to the skin and/or to the respiratory tract. Many of these are useful materials, so to ensure that they can be used safely it is necessary to characterize the hazards and establish appropriate exposure limits. Under new EU legislation (REACH), there is a requirement to define a derived no effect level (DNEL). Where a DNEL cannot be established, e.g. for sensitizing substances, then a derived minimal effect level (DMEL) is recommended. For the bacterial and fungal enzymes which are well recognized respiratory sensitizers and have widespread use industrially as well as in a range of consumer products, a DMEL can be established by thorough retrospective review of occupational and consumer experience. In particular, setting the validated employee medical surveillance data against exposure records generated over an extended period of time is vital in informing the occupational DMEL. This experience shows that a long established limit of 60 ng/m(3) for pure enzyme protein has been a successful starting point for the definition of occupational health limits for sensitization in the detergent industry. Application to this of adjustment factors has limited sensitization induction, avoided any meaningful risk of the elicitation of symptoms with known enzymes and provided an appropriate level of security for new enzymes whose potency has not been fully characterized. For example, in the detergent industry, this has led to general use of occupational exposure limits 3-10 times lower than the 60 ng/m(3) starting point. In contrast, consumer exposure limits vary because the types of exposure themselves cover a wide range. The highest levels shown to be safe in use, 15 ng/m(3), are associated with laundry trigger sprays, but very much lower levels (e.g. 0.01 ng/m(3)) are commonly associated with other types of safe exposure. Consumer limits typically will lie between these values and depend on the actual exposure associated with product use.

Clinicopathologic predictors of the 21-gene assay in a Hispanic cohort

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Background: The 21-gene recurrence score (RS) assay became commercially available (Oncotype DX) in January 2005. It is used to predict the likelihood of distant recurrence in women with estrogen-receptor (ER)-positive, lymph node-negative invasive breast cancer treated with adjuvant tamoxifen. We aimed to identify clinicopathologic predictors of an elevated recurrence score in a group of women with invasive breast cancer living in a predominantly Hispanic population on the Texas-Mexico border. Methods: A retrospective cohort study of 60 consecutive patients with primary ER-positive, lymph node-negative invasive breast cancer who had an Oncotype DX assay performed by Genomic Health, Inc. on paraffin-embedded tumor between March 2006 and November 2008. ER, PR and HER-2 was performed by immunohistochemistry. Patients were classified as low RS (<18), intermediate RS (18–30), or high RS (≥31). Ordinal logistic regression was used to calculate odds ratios (OR) for an increasing RS. Patient age and tumor pathological features were documented in each group. There was no selection bias in ordering the assay. Results: 95% of the cohort was Hispanic. Average age was 55.5 years. 29 patients (48%) had a low RS, 15 (25%) had an intermediate RS, while 16 (27%) had a high RS. HER-2 was amplified in 8 patients (13%). HER-2 positivity was strongly associated with a high RS (p<0.0001). Tumor grade and Ki-67 proliferative index were correlated with one another in a positive fashion (weighted kappa=0.46, p<0.05) and in univariate analyses both factors were significant predictors of a higher RS: tumor grade 3 vs. 1 OR=26.6 (p<0.0001) and Ki-67 proliferative index high vs. low OR=6.59 (p=0.0033). After adjustment, neither OR was significant. A negative progesterone receptor (PR) status was a strong risk factor for a higher RS (adjusted OR=21.64, p=0.0002). Univariate and multivariate ORs for higher RS for invasive ductal vs. invasive lobular carcinoma were, respectively, 4.3 (p=0.051) and 2.23 (p=0.4). Conclusions: Initially, a tumor grade of 3 and a high Ki-67 proliferative index were strong risk factors for a higher RS. However, after controlling for multiple factors, neither tumor grade nor Ki-67 proliferative index had an impact on RS in this predominantly Hispanic cohort.

No significant financial relationships to disclose.

Predictors of permanent menopause after chemotherapy for early-stage breast cancer in premenopausal women

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Background: Optimal choice of endocrine therapy for early-stage breast cancer differs with menopausal status. While amenorrhea is common during adjuvant chemotherapy, there is currently no available test to establish when menopause is permanent. The aim of this study was to determine the age cutoff after which resumption of menses is unlikely following chemotherapy and to assess what additional risk factors may predict for persistent menopause at 5 years after initiation of chemotherapy. Methods: One hundred patients treated with chemotherapy for early-stage premenopausal breast cancer and who remained alive and free of recurrence at least 5 years from the start of treatment were enrolled. Participants were evaluated for current menstrual status and for baseline potential risk factors for menopause: age at start of chemotherapy, race, BMI, smoking history, age at menarche, irregular menses prior to chemotherapy, presence of menses during chemotherapy, type of chemotherapy regimen, hormonal therapy, ovarian protection during chemotherapy, and number of doses of alkylating agent (cyclophosphamide). Recursive partitioning analysis (RPA) was used to identify the age cutoff that best predicts permanent menopause; additional risk factors were assessed using logistic regression analysis. Results: Median age at start of chemotherapy was 43 (range 26–49). RPA identified age >42 at the start of chemotherapy as a significant predictor of permanent menopause (p < 0.001). Cessation of menses during chemotherapy was also associated with permanent menopause (p < 0.001). Both variables remained significant in multivariate analysis (p < 0.001), with the combination of these factors being associated with a 95.4% chance of permanent menopause. Conclusions: In this series, fewer than 5% of premenopausal patients who were at least 42 years old and who experienced cessation of menses during chemotherapy experienced any return of menses over at least 5 years. Upfront use of aromatase inhibitors as adjuvant endocrine therapy for premenopausal hormone-receptor positive breast cancer warrants further investigation for those who are at least 42 years of age and who experience amenorrhea with chemotherapy.

No significant financial relationships to disclose.

Incidence of triple negative breast cancer phenotype in a predominantly Hispanic cohort

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Background: In daily oncology practice, triple-negative invasive breast cancer is defined by negative immunohistochemistry for ER, PR and HER-2. Patients with this phenotype experience poor prognosis due to limited treatment options and intrinsic tumor biology. In a population-based case-control study, the Carolina Breast Cancer Study (Carey et al, JCO, 2004: suppl; abstr 9510), the triple-negative phenotype in African-American women represented 33.9% of the tumors. We aimed to identify the incidence of triple-negative invasive breast cancer in a group of women living in a predominantly Hispanic population on the Texas- Mexico border. Methods: We collected retrospective data for all invasive breast cases diagnosed between January 2005 and December 2008 at our affiliated county hospital. Clinical and pathological features were summarized. ER, PR and HER-2 was performed by immunohistochemistry. Results: 309 patients with invasive breast cancer were identified. 23.9% (74 patients) of all breast cancer patients were triple-negative. 70 of the 74 subjects (94.6%) were Hispanic. There was equal distribution of patients over and under the age of 50. Histologically all cases were invasive ductal carcinoma. The vast majority had grade 3 tumors (82%) with a high Ki-67 proliferative index (97%). Lymphovascular invasion was present in 38 patients (51.4%). Distant metastases at diagnosis was found in 4 patients (5.4%). Conclusions: In our population-based study the proportion of triple-negative invasive breast cancer phenotype was not as high as in the Carolina Breast Cancer Study, but does reflect that a quarter of the patients with invasive breast cancer in this growing Hispanic population may carry this phenotype. The triple-negative phenotype was strongly associated with high tumor grade and proliferative index.

No significant financial relationships to disclose.

Self- perceived Health and Alzheimer Disease Incidence Risk. Data from a Population Based Cohort in Spain: NEDICES Study

Background:

Self-perceived health is a well-recognised predictor of later health outcomes and mortality, but its relationship to incident dementia has been scarcely explored.

Objective:

To analyze self- perceived health as a risk factor for dementia and Alzheimer disease (AD) in a population- based survey of the elderly (NEDICES) Study.

Methods:

Participants were evaluated at baseline (1994-1995) with a standardized questionnaire that included subjective and objective (chronic disorders) health status and screening questions for depression and neurologic disorders. At follow-up (a median of 3.2 years later in 1997-1998) an analogous protocol and neurological assessment were performed.

Results:

Of 5,278 participants evaluated at baseline there were 306 prevalent dementia cases, and 161 incident dementia cases were identified among 3,891 individuals assessed at follow-up (D: 115).

Cox hazard ratio analyses showed that age, stroke and illiteracy were independent risk factors for dementia and AD. Aggregation of vascular risk factors was related to a higher risk of both dementia and AD. Good (and very good) versus less than good (fair, bad and very bad) self-perceived health was an independent risk factor for dementia (CI 95% 1.13- 2.16; p= .006) and AD (CI 95% 1.02- 2.18; p= .038) after adjusting by age, sex education and vascular risk factors.

Discussion:

Self-perceived health increased the risk for incident dementia and AD in the NEDICES cohort as it was previously described in the United Kindom MRC- CFA Study of dementia incidence. Global health measurements (self-perceived health, quality of life) needs farther studies as risk for dementia and AD.

Increasing incidence of fluoroquinolone-resistant Mycobacterium tuberculosis in Mumbai, India

SETTING

Tertiary referral centre, private hospital, Mumbai, India.

OBJECTIVE

To analyse the incidence of fluoroquinolone (FQ) resistant Mycobacterium tuberculosis (TB) in our laboratory from 1995 to 2004.

DESIGN

Retrospective review and analysis of the drug susceptibility test records of all M. tuberculosis culture-positive samples from our Microbiology Department from 1995 to 2004.

RESULTS

FQ resistance has increased exponentially in our laboratory, from 3% in 1996 to 35% in 2004. The incidence of multidrug-resistant tuberculosis has also increased during the same period, from 33% in 1995 to 56% in 2004.

CONCLUSION

The incidence of FQ-resistant M. tuberculosis is gradually increasing to alarming levels. This may be due to widespread use of this vital group of drugs in the treatment of community-acquired infections. We urge that these broad spectrum antibiotics be used judiciously, and ideally be reserved for treatment of resistant TB in TB-endemic areas.

Novel evidences for a tumor suppressor role of Rev3, the catalytic subunit of Pol zeta

Cell cycle checkpoints and DNA repair act in concert to ensure DNA integrity during perturbation of normal replication or in response to genotoxic agents. Deficiencies in these protective mechanisms can lead to cellular transformation and ultimately tumorigenesis. Here we focused on Rev3, the catalytic subunit of the low-fidelity DNA repair polymerase zeta. Rev3 is believed to play a role in double-strand break (DSB)-induced DNA repair by homologous recombination. In line with this hypothesis, we show the accumulation of chromatin-bound Rev3 protein in late S-G2 of untreated cells and in response to clastogenic DNA damage as well as an gamma-H2AX accumulation in Rev3-depleted cells. Moreover, serine 995 of Rev3 is in vitro phosphorylated by the DSB-inducible checkpoint kinase, Chk2. Our data also disclose a significant reduction of rev3 gene expression in 74 colon carcinomas when compared to the normal adjacent tissues. This reduced expression is independent of the carcinoma stages, suggesting that the downregulation of rev3 might have occurred early during tumorigenesis.

The PCR-based detection of Trypanosoma cruzi in the faeces of Triatoma infestans fed on patients with chronic American trypanosomiasis gives higher sensitivity and a quicker result than routine xenodiagnosis

In the xenodiagnosis (XD) of American trypanosomiasis (Chagas disease), Trypanosoma cruzi in the triatomine bugs fed on the patient can now be detected using PCR (XD-PCR) as well as by microscopy (XD-M). In a study to compare XD-PCR with XD-M, triatomine bugs were fed on 50 cases of chronic American trypanosomiasis, of whom only 25 were ever found positive by XD-M. Overall, the bugs fed on 34 of the patients (all 25 cases found positive by XD-M and nine of the other patients) were found PCR-positive, giving a 330-bp fragment corresponding to part of the hyper variable region of the kinetoplast DNA of T. cruzi. Of the 25 patients who were ever found positive by XD-M, 20 gave bugs that were smear-positive on day 90 and a similar number (24; P=0.125) gave bugs that were PCR-positive at this time. On day 30, however, the bugs fed on only 11 of these 25 patients were found positive by microscopy, whereas 23 of these patients were found positive by XD-PCR (P=0.0016). Thus, not only was XD-PCR more sensitive than XD-M but it was also quicker, revealing more cases within 30 days than detected using XD-M over a period of 90 days.

Commercial versus home-made spacers in delivering bronchodilator therapy for acute therapy in children

BACKGROUND

Strong evidence supports the use of metered-dose inhalers combined with a spacer for delivering rapid-acting inhaled beta-2 agonists in the treatment of acute exacerbations of asthma in children. The high cost and lack of availability of commercially produced spacers however, have limited their use in developing countries.

OBJECTIVES

The aim of this review was to compare the response to inhaled beta-2 agonists delivered through metered-dose inhaler using home-made spacers, to the use of commercially produced spacers, in children with acute exacerbations of wheezing or asthma.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) The Cochrane Library Issue 3, 2007,(up to August 2007) MEDLINE , EMBASE, CINHAL, LILACS and reference lists of included studies. We contacted authors and known experts in the field, and approached pharmaceutical companies that manufacture inhalation spacers to identify additional published or unpublished data. No language restrictions were applied.

SELECTION CRITERIA

Trials comparing treatment with rapid acting beta 2-agonists delivered though MDI attached to home-made spacers, with the same bronchodilator therapy delivered with MDI and commercially produced spacers, in children under 18 years with acute exacerbations of wheezing or asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality. Missing data were obtained from the authors or estimated from information available in published reports.

MAIN RESULTS

Six trials with 658 participants met the inclusion criteria . At the time of this report, five trials were published in full text, and one study was available in abstract form only. No significant differences were demonstrated between the two delivery methods in terms of need for hospital admission (RR 1.00, 95% CI 0.63 to 1.59), change in oxygen saturation (SMD -0.03, 95% CI -0.39 to 0.33), PEFR (SMD 0.04, 95% CI -0.72 to 0.80), clinical score (WMD 0.00, 95% CI -0.37 to 0.37), in terms of need for additional treatment (RR 1.18, 95% CI 0.84 to 1.65), or regarding change in heart rate per minute (SMD 0.09, 95% CI -0.24 to 0.42).

AUTHORS' CONCLUSIONS

Overall, this review supports did not identify a difference between these two methods for delivering bronchodilator therapy to children with acute asthma or lower airways obstruction attacks. Care should be taken in the interpretation and applicability of our results because of the small number of RCTs along with few events available meeting the criteria for inclusion in the review, absence of the primary outcome of interest and other clinically important outcomes in the majority of included studies. The possible need for a face-mask in younger children using home-made spacers should also be considered in practice.

Consumer exposure scenarios: development, challenges and possible solutions

Exposure scenarios (ES) under REACH (Registration, Evaluation, and Authorisation of Chemicals; new EU legislation) aim to describe safe conditions of product and substance use. Both operational conditions and risk management measures (RMMs) are part of the ES. For consumer use of chemicals, one of the challenges will be to identify all of the consumer uses of a given chemical and then quantify the exposure derived from each of them. Product use categories can be established to identify in a systematic fashion how products are used. These product categories comprise products that are used similarly (e.g. paints, adhesives). They deliver information about product use characteristics, and provide an easy-to-handle tool for exchanging standardised information. For practical reasons, broad ES will have to be developed, which cover a wide range of products and use. The challenge will be to define them broadly, but not in a way that they provide such an overestimation of exposure that a next iteration or a more complex model is always needed. Tiered and targeted approaches for estimation of exposure at the right level of detail may offer the best solution. RMMs relevant for consumers include those inherent to product design (controllable) and those that are communicated to consumers as directions for use (non-controllable). Quantification of the effect of non-controllable RMMs on consumer exposure can prove to be difficult. REACH requires aggregation of exposure from all relevant identified sources. Development of appropriate methodology for realistic aggregation of exposure will be no small challenge and will likely require probabilistic approaches and comprehensive databases on populations' habits, practices and behaviours. REACH regulation aims at controlling the use of chemicals so that exposure to every chemical can be demonstrated to be safe for consumers, workers, and the environment when considered separately, but also when considered in an integrated way. This integration will be another substantial challenge for the future.