Dermal uptake of nicotine from air and clothing: Experimental verification.

This study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine-exposed clothes, which was demonstrated recently in a preliminary study. Six non-smoking participants were exposed to gaseous nicotine (between 236 and 304 µg/m3 ) over 5 hours while breathing clean air through a hood. Four of the participants wore only shorts and 2 wore a set of clean clothes. One week later, 2 of the bare-skinned participants were again exposed in the chamber, but they showered immediately after exposure instead of the following morning. The 2 participants who wore clean clothes on week 1 were now exposed wearing a set of clothes that had been exposed to nicotine. All urine was collected for 84 hours after exposure and analyzed for nicotine and its metabolites, cotinine and 3OH-cotinine. All participants except those wearing fresh clothes excreted substantial amounts of biomarkers, comparable to levels expected from inhalation intake. Uptake for 1 participant wearing exposed clothes exceeded estimated intake via inhalation by >50%. Biomarker excretion continued during the entire urine collection period, indicating that nicotine accumulates in the skin and is released over several days. Absorbed nicotine was significantly lower after showering in 1 subject but not the other. Differences in the normalized uptakes and in the excretion patterns were observed among the participants. The observed cotinine half-lives suggest that non-smokers exposed to airborne nicotine may receive a substantial fraction through the dermal pathway. Washing skin and clothes exposed to nicotine may meaningfully decrease exposure.

Potentially harmful secondary metabolites produced by indoor Chaetomium species on artificially and naturally contaminated building materials.

The presence of the fungal genus Chaetomium and its secondary metabolites in indoor environments is suspected to have a negative impact on human health and well-being. About 200 metabolites have been currently described from Chaetomium spp., but only the bioactive compound group, chaetoglobosins, have been screened for and thus detected in buildings. In this study, we used a liquid chromatography high-resolution mass spectrometry approach to screen both artificially and naturally infected building materials for all the Chaetomium metabolites described in the literature. Pure agar cultures were also investigated to establish differences between metabolite production in vitro and on building materials as well as in comparison with non-indoor reference strains. On building materials, six different chaetoglobosins were detected in total concentrations of up to 950 mg/m2 from Chaetomium globosum along with three different chaetoviridins/chaetomugilins in concentrations up to 200 mg/m2 . Indoor Chaetomium spp. preferred wood-based materials over gypsum, both in terms of growth rate and metabolite production. Cochliodones were detected for the first time on all building materials infected by both C. globosum and Chaetomium elatum and are thus candidates as Chaetomium biomarkers. No sterigmatocystin was produced by Chaetomium spp. from indoor environment.

Measurements of dermal uptake of nicotine directly from air and clothing.

In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically "smoking" cigarettes, for three hours in a chamber while breathing clean air from head-enveloping hoods. The average nicotine concentration (420 µg/m3 ) was comparable to the highest levels reported for smoking sections of pubs. Urine samples were collected immediately before exposure and 60 hour post-exposure for bare-skinned participants. For the clothed participant, post-exposure urine samples were collected for 24 hour. This participant then entered the chamber for another three-hour exposure wearing a hood and clothes, including a shirt that had been exposed for five days to elevated nicotine levels. The urine samples were analyzed for nicotine and two metabolites-cotinine and 3OH-cotinine. Peak urinary cotinine and 3OH-cotinine concentrations for the bare-skinned participants were comparable to levels measured among non-smokers in hospitality environments before smoking bans. The amount of dermally absorbed nicotine for each bare-skinned participant was conservatively estimated at 570 µg, but may have been larger. For the participant wearing clean clothes, uptake was ~20 µg, and while wearing a shirt previously exposed to nicotine, uptake was ~80 µg. This study demonstrates meaningful dermal uptake of nicotine directly from air or from nicotine-exposed clothes. The findings are especially relevant for children in homes with smoking or vaping.

Associations between selected allergens, phthalates, nicotine, polycyclic aromatic hydrocarbons, and bedroom ventilation and clinically confirmed asthma, rhinoconjunctivitis, and atopic dermatitis in preschool children.

Previous studies, often using data from questionnaires, have reported associations between various characteristics of indoor environments and allergic disease. The aim of this study has been to investigate possible associations between objectively assessed indoor environmental factors and clinically confirmed asthma, rhinoconjunctivitis, and atopic dermatitis. The study is a cross-sectional case-control study of 500 children aged 3-5 years from Odense, Denmark. The 200 cases had at least two parentally reported allergic diseases, while the 300 controls were randomly selected from 2835 participating families. A single physician conducted clinical examinations of all 500 children. Children from the initially random control group with clinically confirmed allergic disease were subsequently excluded from the control group and admitted in the case group, leaving 242 in the healthy control group. For most children, specific IgE's against various allergens were determined. In parallel, dust samples were collected and air change rates were measured in the children's bedrooms. The dust samples were analyzed for phthalate esters, polycyclic aromatic hydrocarbons (PAH), nicotine, and various allergens. Among children diagnosed with asthma, concentrations of nicotine were higher (P < 0.05) and cat allergens were lower (P < 0.05) compared with the healthy controls; air change rates were lower for those sensitized (specific IgE+) compared with those not sensitized (specific IgE-, P < 0.05); and dust mite allergens were higher for specific IgE+ cases compared with healthy controls (P < 0.05). When disease status was based solely on questionnaire responses (as opposed to physician diagnosis), significant associations were found between di(2-ethylhexyl) phthalate (DEHP) and dog allergens in dust and current wheeze.

Children's health and its association with indoor environments in Danish homes and daycare centres - methods.

UNLABELLED: The principle objective of the Danish research program 'Indoor Environment and Children's Health' (IECH) was to explore associations between various exposures that children experience in their indoor environments (specifically their homes and daycare centers) and their well-being and health. The targeted health endpoints were allergy, asthma, and certain respiratory symptoms. The study was designed with two stages. In the first stage, a questionnaire survey was distributed to more than 17,000 families with children between the ages of 1 and 5. The questionnaire focused on the children's health and the environments within the homes they inhabited and daycare facilities they attended. More than 11,000 questionnaires were returned. In the second stage, a subsample of 500 children was selected for more detailed studies, including an extensive set of measurements in their homes and daycare centers and a clinical examination; all clinical examinations were carried out by the same physician. In this study, the methods used for data collection within the IECH research program are presented and discussed. Furthermore, initial findings are presented regarding descriptors of the study population and selected characteristics of the children's dwellings and daycare centers. PRACTICAL IMPLICATIONS: This study outlines methods that might be followed by future investigators conducting large-scale field studies of potential connections between various indoor environmental factors and selected health endpoints. Of particular note are (i) the two-stage design - a broad questionnaire-based survey followed by a more intensive set of measurements among a subset of participants who have been selected based on their responses to the questionnaire; (ii) the case-base approach utilized in the stage 2 in contrast to the more commonly used case-control approach; (iii) the inclusion of the children's daycare environment when conducting intensive sampling to more fully capture the children's total indoor exposure; and (iv) all clinical examinations conducted by the same physician. We recognize that future investigators are unlikely to fully duplicate the methods outlined in this study, but we hope that it provides a useful starting point in terms of factors that might be considered when designing such a study.

Reflections on the state of research: indoor environmental quality.

UNLABELLED: More than 30 years after the First International Indoor Climate Symposium, ten researchers from the USA, Slovakia, Sweden, and Denmark gathered to review the current status of indoor environmental research. We initiated our review with discussions during the 1-day meeting and followed that with parallel research and writing efforts culminating with internal review and revision cycles. In this paper, we present our choices for the most important research findings on indoor environmental quality from the past three decades followed by a discussion of the most important research questions in our field today. We then continue with a discussion on whether there are research areas for which we can 'close the book' and say that we already know what is needed. Finally, we discuss whether we can maintain our identity in the future or it is time to team up with new partners. PRACTICAL IMPLICATIONS: In the early years of this field, the accumulated knowledge was small and it was possible for any researcher to acquire a complete understanding. To do so has become impossible today as what we know has grown to exceed the learning capacity of any person. These circumstances challenge us to work collectively to synthesize what we do know and to define clearly what remains to be learned. If we fail to do these things well, we risk repeating research without memory, an inefficiency that we cannot afford.

Computed tomography of tympanic bullae in pre-weaned dairy calves diagnosed with clinical respiratory disease.

Clinical disease from otitis media in calves is a significant problem in the dairy industry and evaluation of disease severity, chronicity, and imaging remains a challenge. Our objectives were to compare imaging findings in calves with an early diagnosis of respiratory disease to calves with treatment failure. This was a prospective study of 30 Jersey heifer calves, 26-95 days of age, with elevated clinical respiratory scores. Ten clinically healthy calves served as controls for clinical scoring. Three groups of calves were selected based on elevated scores using the McGuirk respiratory scoring system and treatment history. Group A included new cases, group B included primary treatment failures, and group C included multiple treatment failures. Calves underwent a skull CT, four view radiography, post-mortem photography of the tympanic bulla and bacteriological diagnostics. Imaging and post-mortem results were evaluated using normalized scoring schemes. Computed tomography imaging of the tympanic bulla differentiated calves early in the course of disease (group A) from calves that had not responded to treatment (groups B and C). Radiographs differentiated only group C from groups A and B. Use of a 35 degree angle dorsal-right or dorsal-left ventral oblique projection for radiography allowed effective evaluation of the tympanic bulla. Clinical respiratory scores were similar among all three groups. Computed tomography imaging can differentiate early from advanced otitis media. Radiographs, which can be performed in the field, also have utility to identify advanced otitis media to aid management decisions.

Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

BACKGROUND: Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. METHODS: A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. RESULTS: Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). CONCLUSIONS: Anterior RBB with described tooth preparation designs demonstrate a high survival rate.

The double-priming paradigm: a tool for analyzing the functional significance of endogenous event-related brain potentials.

A new paradigm to study the functional significance of 'P300' is presented. Its advantages are: The precise definition and manipulation of cognitive operations which are triggered by the very same events as used for ERP extraction; and a systematic control over the probability of events known to affect endogenous event-related potential components (probabilities of single events, event categories, and event sequences). By employing the paradigm in two experiments with visual stimuli, three subcomponents of 'P300' were identified: P3a; P3b; and positive Slow Wave (pSW). Experimental manipulations revealed that P3b is related to the information processing resources required to alter a perceptual set and pSW to the resources required when abstract information permanently stored in memory must be retrieved. The data further revealed that the same-different disparity in response latency for matching letters has at least two ERP correlates: A difference in P3b latency; and a difference in the amplitude of a negative recess between P3a and P3b.

Auxiliary transplantation of the fetal liver. I. Development of a sheep model.

Current methods of orthotopic liver transplantation are expensive, entail high morbidity and mortality, and are limited by a serious shortage of donor organs for the pediatric recipient. Auxiliary transplantation of livers from anencephalics is a potential solution to the problems of size discrepancy and organ availability for the pediatric patient. To investigate the feasibility of auxiliary fetal liver transplantation, we have developed a sheep model of auxiliary transplantation of the fetal liver into the adult neck. We report here the results of the transplantation of 32 fetal lamb livers ranging in age from 100 to 140 days gestation (term 145 days). We conclude that (1) fetal organ harvest can be effectively accomplished by surface cooling followed by umbilical cold perfusion; (2) auxiliary transplantation of the fetal lamb liver is technically feasible; (3) the fetal liver can survive on umbilical inflow alone but function is improved by hepatic arterial inflow; and (4) the fetal liver is sensitive to excessive flow or pressure and is best transplanted in a parallel vascular arrangement. Auxiliary transplantation of the fetal liver is a promising alternative to current methods of liver transplantation.

Immediate restoration of an immediate single-tooth implant.

Traditional implant protocol specifies an unloaded healing period prior to restoration. Shorter healing times may be appropriate in some circumstances, and examples of early loading have been reported in the dental literature. This case report involves immediate implant placement at the time of tooth extraction, combined with construction of a restoration, inserted directly after implant surgery. The clinical procedures are described, and the specific indications which may permit this approach are presented.

Stability of tobacco smoke odor in enclosed spaces.

During each of five experiments, four sedentary subjects smoked a total of 8 cigarettes during one hour while occupying an odor test chamber. The air temperature was 20-22 degrees C and the relative humidity was 35-50%. During the entire test period (6 h) the odor intensity in the chamber was evaluated by judges. After smoking ceased, the odor intensity continued to rise for one or two hours and then remained constant in a way that is characteristic of unreactive contaminants.

[Asthma caused by methylene-diphenyl-diisocyanate cast in a nurse]. / Asthma forårsaget af methylen-diphenyl-diisocyanat-gips hos en sygeplejerske.

A case of a 35 year-old female nurse without atopic disposition is presented. For one year (1990-1991), she worked in an emergency room, applying synthetic casts containing MDI 0-3 times daily. She developed rhinitis, itchy eyes and nightly wheezing, during employment in the emergency room, with subsequent serious asthma attacks in 1992 and 1996. Just before the last attack, the patient's husband had used insulation foam containing MDI. A specific bronchial provocation test was performed with MDI-based synthetic cast material. The patient developed an asthma attack after seven hours, with a 48% drop in FEV1, suggesting that MDI is the causative agent.

Sensory pollution from bag filters, carbon filters and combinations.

UNLABELLED: Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel of 32 subjects assessed different sets of used filters and identical sets consisting of new filters. Additionally, filter weights and pressure drops were measured at the beginning and end of the operation period. The filter sets included single EU5 and EU7 fiberglass filters, an EU7 filter protected by an upstream pre-filter (changed monthly), an EU7 filter protected by an upstream activated carbon (AC) filter, and EU7 filters with an AC filter either downstream or both upstream and downstream. In addition, two types of stand-alone combination filters were evaluated: a bag-type fiberglass filter that contained AC and a synthetic fiber cartridge filter that contained AC. Air that had passed through used filters was most acceptable for those sets in which an AC filter was used downstream of the particle filter. Comparable air quality was achieved with the stand-alone bag filter that contained AC. Furthermore, its pressure drop changed very little during the 5 months of service, and it had the added benefit of removing a large fraction of ozone from the airstream. If similar results are obtained over a wider variety of soiling conditions, such filters may be a viable solution to a long recognized problem. PRACTICAL IMPLICATIONS: The present study was designed to address the emission of sensory offending pollutants from loaded ventilation filters. The goal was to find a low-polluting solution from commercially available products. The results indicate that the use of activated carbon (AC) filters downstream of fiberglass bag filters can reduce the degradation of air quality that occurs with increasing particle loading. A more practical solution, yet comparably effective, is a stand-alone particle filter that incorporates AC. In either case, further testing under a variety of conditions is recommended before making design decisions regarding the type of filters best suited to efficient building operation.

Initial studies of oxidation processes on filter surfaces and their impact on perceived air quality.

Used filters can be a strong sensory pollutant source. Oxidation processes, especially those initiated by ozone, may contribute to the pollutants emitted from such filters. In the present study, ozone was added to the airstream passing through used ventilation filters. Two flow rates were examined. While the upstream ozone concentration was approximately 75 ppb, the concentrations downstream of the filter were initially 35-50% lower. However, within an hour downstream concentrations were only 5-10% lower than those upstream. These filter samples were then placed for 48 h in nitrogen, ambient air containing less than 5 ppb ozone, or ambient air at an elevated temperature. This resulted in partial regeneration of the ozone removal capability of the filter. In analogous experiments, lower ozone removal occurred when the filter samples were first ventilated for 24 h with ozone-free air before making the measurements. Samples from a new filter removed <10% of the ozone in the airstream, and removal remained relatively constant over time. In companion studies, human subjects assessed the air passing through various used filter samples. In the initial evaluation each of the four filter samples, taken from the same filter and ventilated for 24 h, were assessed to be equivalent. The next evaluation was immediately after the samples had been kept for 24 h in either nitrogen, air, air at an elevated temperature or ozone. The nitrogen-treated filter was assessed to be best, while the ozone-treated filter was assessed to be the worst. The final evaluation occurred after ambient air had passed through the 'treated' filters for 2 h. All such ventilated filters were assessed to be more acceptable than immediately after the 24-h treatments; the ozonized and air-treated filters were the most polluting of the four. Practical Implications The present paper supports previous findings that loaded ventilation filters can be significant sources of sensory pollution. Replacing a loaded filter with a new filter temporarily removes this source of pollution. However, the present study does not provide an answer to how frequently changes are needed under different conditions. The results indicate that in cases of intermittent operation of ventilation systems, the airflow through the polluted filters should be restarted in sufficient time prior to occupancy to purge odorous pollutants that have accumulated on the filter surface. Removal of ozone upstream of the particle filters may further improve perceived air quality in the space downstream of the filter bank. Future efforts related to the development and application of low-polluting filtration systems are warranted.

[Patient satisfaction and geriatric care - an empirical study]. / Patientenzufriedenheit in der Geriatrie - Eine empirische Untersuchung.

Patients' satisfaction has become a central concept in quality assurance. Despite progress in research in this area is still a lack of data for geriatric patients. Referring to the consumer model, satisfaction can be described as a difference between expectations and assessed performance. The aim of this study is to analyze satisfaction among geriatric patients in an in-patient setting. A personal interview was performed 1-2 days before discharge. Patients suffering for dementia or with problems to communicate were excluded. 124 of 268 geriatric patients who were discharged in 2003 were included (inclusion rate 46.3%). 119 were willing to participate (response rate 96.0%). Respondents were between 61 and 96 years old, 39% were male and 42% had serious functional limitations at time of admission. Multiple linear regression analysis revealed three significant predictors of a combined index of satisfaction and expectations: a) quality of hotel services; b) experience of neglect; c) provision of medical information and skills. In summary, standardized personal questionnaires can provide valid and reliable data of geriatric patients. Satisfaction of elderly patients is negatively affected by neglect and positively influenced by provision of medical information and a good hotel services.

Ventilation filters and indoor air quality: a review of research from the International Centre for Indoor Environment and Energy.

UNLABELLED: The presence of a used filter in a ventilation system can have an adverse impact on perceived air quality, SBS symptoms, and performance of office work. The present paper reviews the studies leading to this conclusion and discusses recent work that has been performed in a search for the mechanisms involved. One promising hypothesis involves chemical reactions on the surface of the collected particles in the formation of noxious compounds. Finally, a discussion on engineering solutions is presented. PRACTICAL IMPLICATIONS: Loaded particle filters provide a significant source of air pollution. To counteract this, filters should be changed frequently or an alternative method of removing particles from the air should be applied.

The lingual locking screw for implant-retained restorations--aesthetics and retrievability.

The ability to retrieve a restoration is often cited as an advantage of implant-borne prostheses. Cemented prostheses, particularly in single-tooth cases, have been promoted for aesthetic reasons, and to allow increased positional flexibility in fixture placement. However, this approach may compromise restoration retrieval. This paper discusses the concept of a secondary locking screw, which allows latitude in fixture position, good aesthetics, and retrievability.