Does improving indoor air quality lessen symptoms associated with chemical intolerance?

AIM: To determine whether environmental house calls that improved indoor air quality (IAQ) is effective in reducing symptoms of chemical intolerance (CI). BACKGROUND: Prevalence of CI is increasing worldwide. Those affected typically report symptoms such as headaches, fatigue, 'brain fog', and gastrointestinal problems - common primary care complaints. Substantial evidence suggests that improving IAQ may be helpful in reducing symptoms associated with CI. METHODS: Primary care clinic patients were invited to participate in a series of structured environmental house calls (EHCs). To qualify, participants were assessed for CI with the Quick Environmental Exposure and Sensitivity Inventory. Those with CI volunteered to allow the EHC team to visit their homes to collect air samples for volatile organic compounds (VOCs). Initial and post-intervention IAQ sampling was analyzed by an independent lab to determine VOC levels (ng/L). The team discussed indoor air exposures, their health effects, and provided guidance for reducing exposures. FINDINGS: Homes where recommendations were followed showed the greatest improvements in IAQ. The improvements were based upon decreased airborne VOCs associated with reduced use of cleaning chemicals, personal care products, and fragrances, and reduction in the index patients' symptoms. Symptom improvement generally was not reported among those whose homes showed no VOC improvement. CONCLUSION: Improvements in both IAQ and patients' symptoms occur when families implement an action plan developed and shared with them by a trained EHC team. Indoor air problems simply are not part of most doctors' differential diagnoses, despite relatively high prevalence rates of CI in primary care clinics. Our three-question screening questionnaire - the BREESI - can help physicians identify which patients should complete the QEESI. After identifying patients with CI, the practitioner can help by counseling them regarding their home exposures to VOCs. The future of clinical medicine could include environmental house calls as standard of practice for susceptible patients.

Validation of a Brief Screening Instrument for Chemical Intolerance in a Large U.S. National Sample.

BACKGROUND: Chemical intolerance (CI) is characterized by multisystem symptoms triggered by low levels of exposure to xenobiotics including chemicals, foods/food additives, and drugs/medications. Prior prevalence estimates vary from 8-33% worldwide. Clinicians and researchers need a brief, practical screening tool for identifying possible chemical intolerance. This large, population-based study describes the validation of a three-item screening questionnaire, the Brief Environmental Exposure and Sensitivity Inventory (BREESI), against the international reference standard used for assessing chemical intolerance, the Quick Environmental Exposure and Sensitivity Inventory (QEESI). METHODS: More than 10,000 people in the U.S. responded to the BREESI and the QEESI in a population-based survey. We calculated the overall prevalence of CI in this sample, as well as by gender, age, and income. Common statistical metrics were used to evaluate the BREESI as a screener for CI against the QEESI. RESULTS: The prevalence estimate for QEESI-defined chemical intolerance in the U.S. was 20.39% (95% CI 19.63-21.15%). The BREESI had 91.26% sensitivity (95% CI: 89.20-93.04%) and 92.89% specificity (95% CI: 91.77-93.90%). The positive likelihood ratio was 12.83 (95% CI: 11.07-14.88), and the negative likelihood ratio was 0.09 (95% CI: 0.08-0.12). Logistic regression demonstrates that the predicted probability of CI increased sharply with each increase in the number of BREESI items endorsed (Odds Ratio: 5.3, 95% CI: 4.90-5.75). CONCLUSIONS: Chemical intolerance may affect one in five people in the U.S. The BREESI is a new, practical instrument for researchers, clinicians, and epidemiologists. As a screening tool, the BREESI offers a high degree of confidence in case ascertainment. We recommend: screen with the BREESI, confirm with the QEESI.

Texas needs physicians trained in public health: a new 4-year integrated MD/MPH degree program.

Traditionally, medicine and public health have not worked as synergistic disciplines because they are based on fundamentally different models. However, a number of very recent imperatives emphasize the need for dual training in these fields to address major public health problems facing society as well as the documented and forecasted workforce shortages. In response to this need, two University of Texas institutions based in San Antonio, Texas, partnered in 2007 to offer a dual 4-year Doctor of Medicine/Master of Public health (MD/MPH) degree program, one of a handful in the nation. Approximately 65 students (or 10% of three consecutive medical school classes) are currently enrolled. The dual-degree program meets the requirements of both degree programs while giving shared MPH credit for relevant courses taken in the medical curriculum and medical school credit for some courses in the public health curriculum. However, 75% of the MPH coursework originates at the School of Public Health. Initial results from focus groups conducted after the first year showed a high degree of student satisfaction, with frequent comments that the program was broadening their perspective on medicine and influencing their career and life goals. A dual MD/MPH degree is an important option for all medical students as a means of addressing pressing health issues in our society through combined training in medicine and the broader areas of prevention and population health. The four-year MD/MPH program, while posing challenges for faculty and students, attracts community- and prevention-minded medical students, reduces training costs (housing/living costs and lost time and wages before entering residency), and allows students to progress with the rest of their class.

Explaining low rates of autism among Hispanic schoolchildren in Texas.

In data from the Texas Educational Agency and the Health Resources and Services Administration, we found fewer autism diagnoses in school districts with higher percentages of Hispanic children. Our results are consistent with previous reports of autism rates 2 to 3 times as high among non-Hispanic Whites as among Hispanics. Socioeconomic factors failed to explain lower autism prevalence among Hispanic schoolchildren in Texas. These findings raise questions: Is autism underdiagnosed among Hispanics? Are there protective factors associated with Hispanic ethnicity?

The alpha and beta subunits of the metalloprotease meprin are expressed in separate layers of human epidermis, revealing different functions in keratinocyte proliferation and differentiation.

The zinc endopeptidase meprin (EC 3.4.24.18) is expressed in brush border membranes of intestine and kidney tubules, intestinal leukocytes, and certain cancer cells, suggesting a role in epithelial differentiation and cell migration. Here we show by RT-PCR and immunoblotting that meprin is also expressed in human skin. As visualized by immunohistochemistry, the two meprin subunits are localized in separate cell layers of the human epidermis. Meprin alpha is expressed in the stratum basale, whereas meprin beta is found in cells of the stratum granulosum just beneath the stratum corneum. In hyperproliferative epidermis such as in psoriasis vulgaris, meprin alpha showed a marked shift of expression from the basal to the uppermost layers of the epidermis. The expression patterns suggest distinct functions for the two subunits in skin. This assumption is supported by diverse effects of recombinant meprin alpha and beta on human adult low-calcium high-temperature keratinocytes. Here, beta induced a dramatic change in cell morphology and reduced the cell number, indicating a function in terminal differentiation, whereas meprin alpha did not affect cell viability, and may play a role in basal keratinocyte proliferation.

Bathing suit ichthyosis is caused by transglutaminase-1 deficiency: evidence for a temperature-sensitive phenotype.

Bathing suit ichthyosis (BSI) is a striking and unique clinical form of autosomal recessive congenital ichthyosis characterized by pronounced scaling on the bathing suit areas but sparing of the extremities and the central face. Here we report on a series of 10 BSI patients. Our genetic, ultrastructural and biochemical investigations show that BSI is caused by transglutaminase-1 (TGase-1) deficiency. Altogether, we identified 13 mutations in TGM1-among them seven novel missense mutations and one novel nonsense mutation. Structural modeling for the Tyr276Asn mutation reveals that the residue is buried in the hydrophobic interior of the enzyme and that the hydroxyl side chain of Tyr276 is exposed to solvent in a cavity of the enzyme. Cryosections of healthy skin areas demonstrated an almost normal TGase activity, in contrast to the affected BSI skin, which only showed a cytoplasmic and clearly reduced TGase-1 activity. The distribution of TGase-1 substrates in the epidermis of affected skin corresponded to the situation in TGase-1 deficiency. Interestingly, the expression of TGase-3 and cathepsin D was reduced. Digital thermography validated a striking correlation between warmer body areas and presence of scaling in patients suggesting a decisive influence of the skin temperature. In situ TGase testing in skin of BSI patients demonstrated a marked decrease of enzyme activity when the temperature was increased from 25 to 37 degrees C. We conclude that BSI is caused by TGase-1 deficiency and suggest that it is a temperature-sensitive phenotype.