Analysis of the clinical state of patients with occupational asthma following cessation of exposure to allergens.
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The purpose of this study was to evaluate the health state of patients with occupational asthma after cessation of occupational exposure to bakery allergens. A follow-up study of 56 subjects with occupational asthma was carried out. Subjects were examined twice: 1-6 months after removal from occupational exposure and 36 or 48 months later. Clinical state analysis both at diagnosis and re-examination was performed with the use of a questionnaire. Functional spirometric tests and skin prick tests and/or specific serum IgE were carried out during both examinations at points of time at which the subjects regarded their asthma symptoms as least severe. According to the subjective evaluation of the patients' clinical state, some improvement could be noticed 36 or 48 months after removal from work. Forced expiratory volume in one second (FEV1) and peak respiratory flow (PEF) did not change significantly. Total serum IgE concentration decreased in only two subjects, but the mean value of total IgE level did not significantly differ at the first and second examination after the cessation of occupational exposure. There was no significant difference in the number of positive skin prick tests to common and occupational allergens between the first and second examination. The majority of patients with occupational asthma reporting subjectively on their symptoms indicated an improvement in their clinical state 2-3 years after removal from occupational exposure. The intensity of skin prick tests was not reduced in the studied group. Non-specific bronchial hyper-responsiveness was not reduced in the majority of subjects with occupational asthma at least 2 years after cessation of occupational exposure. (+info)
The elasticity and failure of fluid-filled cellular solids: theory and experiment.
(42/1384)
We extend and apply theories of filled foam elasticity and failure to recently available data on foods. The predictions of elastic modulus and failure mode dependence on internal pressure and on wall integrity are borne out by photographic evidence of distortion and failure under compressive loading and under the localized stress applied by a knife blade, and by mechanical data on vegetables differing only in their turgor pressure. We calculate the dry modulus of plate-like cellular solids and the cross over between dry-like and fully fluid-filled elastic response. The bulk elastic properties of limp and aging cellular solids are calculated for model systems and compared with our mechanical data, which also show two regimes of response. The mechanics of an aged, limp beam is calculated, thus offering a practical procedure for comparing experiment and theory. This investigation also thereby offers explanations of the connection between turgor pressure and crispness and limpness of cellular materials. (+info)
An outbreak of cryptosporidiosis linked to a foodhandler.
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In September and October 1998, a cryptosporidiosis outbreak occurred on a Washington, DC, university campus. In a case-control study of 88 case patients and 67 control subjects, eating in 1 of 2 cafeterias was associated with diarrheal illness (P<.001). Morbidity was associated with eating dinner on 22 September (odds ratio, 8.1; 95% confidence interval, 3.4-19.5); weaker associations were found for 6 other meals. Cryptosporidium parvum was detected in stool specimens of 16 (70%) of 23 ill students and 2 of 4 ill employees. One ill foodhandler with laboratory-confirmed C. parvum prepared raw produce on 20-22 September. All 25 Cryptosporidium isolates submitted for DNA analysis, including 3 from the ill foodhandler, were genotype 1. This outbreak illustrates the potential for cryptosporidiosis to cause foodborne illness. Epidemiologic and molecular evidence indicate that an ill foodhandler was the likely outbreak source. (+info)
Transmission of calicivirus by a foodhandler in the pre-symptomatic phase of illness.
(44/1384)
After a Christmas party in a restaurant, 48 (68%) of the 82 guests contracted calicivirus gastroenteritis. The epidemiological investigation showed that salad was strongly associated with the disease episode (RR = 2.43, P = 0.0005). Similar symptoms occurred among other customers who had had a meal at the same restaurant on the same evening. A foodhandler who had only prepared salad and appetizers became sick about 30 min after the end of his shift. He had been free of symptoms while preparing food. Few outbreak investigations have shown calicivirus transmission by foodhandlers some hours before becoming symptomatic. (+info)
Healthy adults demonstrate less skin reactivity to commercial extracts of commonly ingested food than to D. farinae.
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The aim of this study is to determine the skin reactivity of healthy Oriental adults to commercial extracts of commonly ingested food and the house dust mite D. farinae, a common local aeroallergen. D. farinae and 18 food extracts were skin prick tested on adults without any personal history of atopic diseases and food allergy. The extracts of food not consumed by any subject on religious or personal grounds were not tested for that individual. A total of 103 healthy adults who fulfilled the selection criteria were skin prick tested. There were 35 males and 68 females. Their mean age was 29 years (SD +/- 7.5) with a range of 19 to 49 years. Sixty-eight percent were Chinese, 12.6% Malay, 12.6% Indian and 6.8% other Oriental races. Fifty-four (52.4%) were positive for D. farinae while only 12 (11.7%) were positive for at least one food extract The food extract that gave the most number of positive reactions was shellfish mix (5/102, 4.9%). A family history of atopy did not have any significant correlation with the results of skin test. It was concluded that healthy adults demonstrate less skin reactivity to extracts of commonly ingested food than to D. farinae. (+info)
Dietary factors that affect the bioavailability of carotenoids.
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Carotenoids are thought to contribute to the beneficial effects of increased vegetable consumption. Various dietary factors have an effect on the bioavailability of carotenoids. The type of food matrix in which carotenoids are located is a major factor. The bioavailability of beta-carotene from vegetables in particular has been shown to be low (14% from mixed vegetables) compared with that of purified beta-carotene added to a simple matrix (e.g., salad dressing), whereas for lutein, the difference is much smaller (relative bioavailability of 67% from mixed vegetables). Processing, such as mechanical homogenization or heat treatment, has the potential to enhance the bioavailability of carotenoids from vegetables (from 18% to a sixfold increase). The amount of dietary fat required to ensure carotenoid absorption seems low (approximately 3-5 g per meal), although it depends on the physicochemical characteristics of the carotenoids ingested. Unabsorbable, fat-soluble compounds reduce carotenoid absorption, and interaction among carotenoids may also result in a reduced carotenoid bioavailability. Research into the functional benefits of carotenoids should consider the fact that the bioavailability of beta-carotene in particular is one order of magnitude higher when provided as a pure compound added to foods than when it is present naturally in foods. (+info)
Effects of pelleting and storage of a complex nursery pig diet on lysine bioavailability.
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The effects of pelleting and storage of a complex nursery pig diet (28% lactose and 1.4% lysine) on lysine bioavailability were assessed in a chick bioassay. The nursery diet was steam-conditioned at 60 degrees C for 45 s and then pelleted through a 5-mm die with a depth of 38 mm. Samples of meal and pelleted diet were placed in metallic feeders in an occupied nursery facility for 1 wk (warm) or were stored at 4 degrees C (cool). For the standard-curve bioassay, a total of 144 8-d-old chicks were offered the following dietary treatments: 1 to 3) a basal diet (lysine deficient) and two levels (.08 and .16%) of added lysine (from L-lysine-HCl); 4 and 5) two positive controls (.7% added lysine with or without 10% of the nursery diet); and 6 to 9) basal diet plus 10% of one of the four nursery diet samples (meal or pellet stored cool or warm for 1 wk). Pelleting had no effect (P>.10) on lysine bioavailability, probably because pelleting conditions (temperature, humidity, and pellet size) were not aggressive enough to result in detectable effects on lysine utilization. However, storage in the nursery facility for 1 wk reduced (P<.03) lysine bioavailability by an average of 10%. No significant (P>.10) interactions were observed. Furthermore, true digestibility of lysine in the four pig diet samples was estimated in a cecectomized cockerel digestibility assay using 15 adult Single-Comb White Leghorn cockerels. Lysine digestibility in all samples was high (average of 94%) and was not affected (P>.10) by treatment. We conclude that the pelleting conditions used in our experiments did not decrease lysine utilization. More research is needed to define thermal processing conditions that might cause protein quality deterioration. However, typical warm and humid environmental conditions encountered in modern nursery facilities have a negative effect on protein quality of diets rich in reducing sugars and lysine. (+info)
Prospective study of work related respiratory symptoms in trainee bakers.
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OBJECTIVES: To investigate the occurrence of work related respiratory symptoms and to assess the effect of atopy in a group of trainee bakers. METHODS: A prospective study of work related respiratory symptoms among 125 trainee bakers who were investigated with a questionnaire plus skin prick test with wheat flour and alpha-amylase allergens at baseline and then after 6, 18, and 30 months. RESULTS: At the baseline examination, four students (3.2%) complained of respiratory symptoms (cough and rhinitis) when working with flours and four were skin positive to wheat flour or alpha-amylase. The incidence of work related respiratory symptoms was 3.4% at 6 months, and the cumulative incidence was 4.8% and 9.0% at 18 and 30 months, respectively. The incidence of skin sensitisation to occupational allergens was 4.6% at 6 months and the cumulative incidence was 4.6% at 18 months and 10.1% at 30 months. The generalised estimating equation approach to longitudinal data showed that work related respiratory symptoms in the study population was significantly associated with a personal history of allergic disease (odds ratio (OR) 5.8, 95% confidence interval (95% CI) 1.8 to 18.2) and skin sensitisation to wheat flour or alpha-amylase (OR 4.3, 95% CI 1.2 to 14.9). Atopy based on prick test was not related to the occurrence of work related respiratory symptoms over time (OR 1.1, 95% CI 0.3 to 3.8). CONCLUSIONS: Personal history of allergic disease is a predisposing factor for the development of symptoms caused by exposure to wheat flour and may be a criterion of unsuitability for starting a career as a baker. Atopy based on the skin prick test is useful for identifying subjects with allergic disease, but should not be used to exclude non-symptomatic atopic people from bakery work. (+info)