The increasing importance of LNAA supplementation in phenylketonuria at higher plasma phenylalanine concentrations.

BACKGROUND: Large neutral amino acid (LNAA) treatment has been suggested as alternative to the burdensome severe phenylalanine-restricted diet. While its working mechanisms and optimal composition have recently been further elucidated, the question whether LNAA treatment requires the natural protein-restricted diet, has still remained. OBJECTIVE: Firstly, to determine whether an additional liberalized natural protein-restricted diet could further improve brain amino acid and monoamine concentrations in phenylketonuria mice on LNAA treatment. Secondly, to compare the effect between LNAA treatment (without natural protein) restriction and different levels of a phenylalanine-restricted diet (without LNAA treatment) on brain amino acid and monoamine concentrations in phenylketonuria mice. DESIGN: BTBR Pah-enu2 mice were divided into two experimental groups that received LNAA treatment with either an unrestricted or semi phenylalanine-restricted diet. Control groups included Pah-enu2 mice on the AIN-93 M diet, a severe or semi phenylalanine-restricted diet without LNAA treatment, and wild-type mice receiving the AIN-93 M diet. After ten weeks, brain and plasma samples were collected to measure amino acid profiles and brain monoaminergic neurotransmitter concentrations. RESULTS: Adding a semi phenylalanine-restricted diet to LNAA treatment resulted in lower plasma phenylalanine but comparable brain amino acid and monoamine concentrations as compared to LNAA treatment (without phenylalanine restriction). LNAA treatment (without phenylalanine restriction) resulted in comparable brain monoamine but higher brain phenylalanine concentrations compared to the severe phenylalanine-restricted diet, and significantly higher brain monoamine but comparable phenylalanine concentrations as compared to the semi phenylalanine-restricted diet. CONCLUSIONS: Present results in PKU mice suggest that LNAA treatment in PKU patients does not need the phenylalanine-restricted diet. In PKU mice, LNAA treatment (without phenylalanine restriction) was comparable to a severe phenylalanine-restricted diet with respect to brain monoamine concentrations, notwithstanding the higher plasma and brain phenylalanine concentrations, and resulted in comparable brain phenylalanine concentrations as on a semi phenylalanine-restricted diet.

[Investigation of the mite fauna content of dust samples collected from pig and poultry farms. Report of the first finding in Western Europe of the house-dust mite Dermatophagoides evansi in dust from poultry houses]. / Een oriënterend onderzoek naar de mijtenfauna in stofmonsters uit varkens- en pluimveestalen in Nederland. Eerste vondst van de huisstofmijt Dermatophagoides evansi in pluimvee-stalstof in West-Europa.

Mites can be important sources of airborne allergens, especially on farms. Two dust samples from pig farms and three dust samples from poultry farms were investigated for mites. House-dust mites were present in the poultry-dust samples, but not in the pig-dust samples. Furthermore, storage mites and predatory mites also were found in the poultry-dust samples. Specifically, the house-dust mite Dermatophagoides evansi was found in the dust samples from two poultry farms. Subsequently, a dust sample was collected from five other poultry farms. Again, D. evansi was present in dust from these farms. This is the first time that D. evansi is reported in dust from poultry farms in Western Europe outside Norway. If D. evansi cross-reacts with other Dermatophagoides spp., then poultry farmers and their families, but also other professionals working in the poultry industry, such as veterinarians, may be exposed to house-dust mites with potential clinical consequences, both domestic and occupational.

Veterinary practice and occupational health. An epidemiological study of several professional groups of Dutch veterinarians. I. General physical examination and prevalence of allergy, lung function disorders, and bronchial hyperreactivity.

The prevalence of allergy, lung function disorders, and bronchial hyperreactivity was studied in 102 Dutch veterinarians, subdivided into five professional groups (predominantly working with either swine, cattle, poultry, companion animals, or as a non-practitioner). The mean age of the participants was 43 years; 6 participants were females. Twenty-two per cent of the participants were overweight, and relatively more non-practitioners than practitioners were overweight. Approximately 23% of the vets reported complaints of prolonged fatigue. The data suggest a relationship between complaints of prolonged fatigue and a more than average number of daily working hours. Only a small proportion of vets were sensitized against several allergens. There were no significant differences in prevalence of distinct lung function disorders or bronchial hyperreactivity between professional groups. It is hypothesized that the respiratory complaints (chronic coughing, chronic phlegm production, stuffed nose, sneezing) reported by the vets predominantly working in swine and/or poultry practice could be caused by irritation and/or inflammation of the first part of the trachea-bronchial tree that has no measurable and permanent consequences for changes in lung function or increased bronchial hyperreactivity. The results of a skin test against allergens and determination of allergen-specific IgE in blood indicated that the respiratory complaints were probably not related to allergy against the panel of allergens tested.

Veterinary practice and occupational health. An epidemiological study of several professional groups of Dutch veterinarians. II. Peak expiratory flow variability, dust and endotoxin measurements, use of respiratory protection devices, and time distribution of professional activities.

Dust and endotoxin exposure was measured in the Spring and Autumn in 96 veterinary practitioners, subdivided in four professional groups ((predominantly working with either swine, cattle, poultry, or companion animals). Furthermore, peak expiratory flow (PEF) variability was measured four times a day over a week in Spring and Autumn in order to detect occupation-related respiratory disorders. The participants kept a log book in which they recorded their activities during these periods. Practitioners working with swine, cattle, or poultry had a significantly higher exposure to dust (+/- 5 times) and endotoxin (+/- 10 times) than companion animal practitioners. PEF variability measurements gave no indications for an increased prevalence of bronchial hyperreactivity related to occupational activities. Respiratory protective devices (RPD) were used selectively. Only a small proportion of the practitioners used them at any time when entering a animal confinement building. Swine and cattle practitioners worked for approximately 3.6 hours per day in animal buildings, whereas poultry practitioners worked in the environment of poultry buildings for approximately 2.8 hours per day.

The value of an in-hospital insect sting challenge as a criterion for application or omission of venom immunotherapy.

BACKGROUND: Venom immunotherapy is a generally accepted treatment for serious allergy to bee and yellow jacket venom. However, it is not precisely known to whom venom immunotherapy should be offered. OBJECTIVE: The purpose of this study was to determine whether an in-hospital insect sting challenge (IHC) can be used as a criterion for application or omission of venom immunotherapy. METHODS: An IHC was carried out in a group of 479 patients (136 sensitized to bee venom and 343 sensitized to yellow jacket venom). The patients with a negative IHC response were interviewed about their experience with subsequent stings under natural circumstances. RESULTS: A total of 76 of 136 bee-sensitized patients (56%) and 284 of 343 yellow jacket-sensitized patients (83%) had a negative IHC response. All of the patients who had a systemic reaction after the IHC were advised to receive venom immunotherapy. The success rate of this therapy was 96.4% for patients allergic to bee venom (54 of 56) and 91.4% for patients allergic to yellow jacket venom (53 of 58). Of a total of 76 bee-sensitized patients with negative IHC responses, 41 were subsequently stung in the field; six patients had a mild (Mueller grade I) systemic reaction (14.6%). Of a total of 284 yellow jacket-sensitized with negative IHC responses, 127 were subsequently stung in the field; nine patients had a mild (Mueller grades I and II) systemic reaction (7.1%), and four patients had a severe (Mueller grades III and IV) systemic reaction (3.1%). Without an IHC as a selection criterion for venom immunotherapy, the percentage of patients unnecessarily treated was calculated to be 48% for bee venom-sensitized patients and 74% for yellow jacket-sensitized patients. However, with a negative test IHC response as a selection criterion for the omission of venom immunotherapy, 14.6% of the bee venom-sensitized patients and 10.2% of the yellow jacket-sensitized patients were proven to be at risk for systemic reactions on subsequent field stings. CONCLUSION: Venom immunotherapy with bee or yellow jacket venom is justifiable only after a positive response to an IHC is observed.

Prevalence of self-reported respiratory disease symptoms among veterinarians in the Southern Netherlands.

In June 1991, 831 veterinarians registered in the Southern Netherlands were mailed a questionnaire to obtain details of work practice and health problems. One hundred fifty-two veterinarians were not eligible (retired or not working regularly), 497 practitioners returned a complete questionnaire (73% response rate). The purpose was to assess the prevalence of respiratory disease symptoms (RDS) and to compare the prevalence of RDS between occupational specialties and with a group of swine farmers. The professional specialty of each veterinarian was grouped as: small-animal practice (17%), large-animal practice (51%), mixed-animal practice (14%), and other practice (i.e., government, industry) (18%). Adjusted for age, gender, smoking, history of atopy, and use of respiratory protective devices, large-animal practitioners had a two times higher odds of chronic cough (OR = 1.8, 95% CI 1.1-2.8) or chronic phlegm production (OR = 2.1, 95% CI 1.1-3.7) and a three times higher odds of chest wheezing (OR = 2.8, 95% CI 1.3-6.3) than veterinarians with another specialty. Modelling the occurrence of RDS in veterinarians with exposure variables indicated that working more than 20 hr per week in swine confinement buildings increased the odds of occurrence of chronic cough and chronic phlegm production approximately three times, in addition to a significant effect of smoking. Besides a significant effect of smoking and history of atopy, no exposure variables other than occupation were associated with occurrence of asthmatic attacks in swine farmers and large-animal practitioners. Large-animal practitioners had a two times higher odds of asthmatic attacks (OR = 1.8, 95% CI 1.1-2.9) than swine farmers. Large-animal practitioners have a considerably higher proportion of symptoms like cough, phlegm production, a stuffed up nose, sneezing, and tearing eyes than small-animal practitioners during, and 4-8 hr after, working with animals.

[Professional practice and health status of veterinarians]. / Beroepsuitoefening en gezondheid van de dierenarts.

By carrying out an inquiry by mail to 925 veterinarians in the Southern Netherlands, there was looked after a relationship between the professional practice of the veterinarian and his health status. The inquiry was completed and returned by 453 veterinarians. The questions about the health status dealt with complaints about: the respiratory tract, the stand and motion apparatus and the hearing. Based on over 75% of the work package the veterinarians were divided into: veterinarians in the large animal practice, veterinarians in the small animal practice and veterinarians with an other job. The results are compared with the results of a comparable inquiry by pig farmers. Veterinarians, who do smoke, have twice as much respiratory complaints than no smoking veterinarians. Veterinarians in the large animal practice have more respiratory complaints, more complaints about elbows and wrists and more deafness. Veterinarians in the small animal practice have more complaints about allergies, and more complaints about the back and the knees and feet.

Emergency treatment of allergic reactions to Hymenoptera stings.

Allergic reactions to Hymenoptera stings are frequently observed all over Europe. Rarely they may induce long-standing morbidity or even be fatal. Several investigations have shown that the emergency treatment given to these patients is often inadequate. Cutaneous symptoms respond well to antihistamines and also to adrenaline. Adrenaline is the mainstay for outside hospital treatment of more severe reactions involving the respiratory tract (bronchial asthma, laryngeal oedema) and the cardiovascular system (anaphylactic shock). Inhaled adrenaline is especially useful in respiratory symptoms, while parenteral application of adrenaline is prefered for shock treatment. All patients with severe respiratory or cardiovascular reactions must be hospitalized, treated under intensive care conditions and observed for at least 24 hr. Emergency medications including adrenaline for inhalation or for self-injection must be given to all patients with a history of systemic allergic reactions to hymenoptera stings. These patients must also get instructions for safety measures to avoid further stings. They should be referred to an allergist in order to evaluate the indication for venom immunotherapy.

The evaluation of the common diagnostic methods of hypersensitivity for bee and yellow jacket venom by means of an in-hospital insect sting.

Between 1979 and 1983 230 patients visited our clinic in connection with allergic reactions after insect stings. One hundred six patients were subjected to a diagnostic provocation test with a live insect; 86 of these patients had a history of systemic reactions and a positive skin test and RAST with insect venom. Thirty-one of these patients, including one patient with a negative RAST and another with a negative skin test, demonstrated a generalized reaction and were subjected to immunotherapy with pure insect venom. Comparison of the diagnostic data from 31 patients with reactions with those of the 57 nonreacting patients from the 86 patients aforementioned reveals that at this time only a provocation test with a live insect can provide the evidence of an allergy to insect venom leading to such a severe generalized reaction that admission to probably lifelong immunotherapy is justified. The measurement of the venom-specific IgG, the ratio of IgG/IgE, and (for bee patients) the serum antibody titer against the bee venom components phospholipase A and hyaluronidase did not improve the diagnosis of a current hypersensitivity against insect venom.