Accelerated solvent extraction and gas chromatography/mass spectrometry for determination of polycyclic aromatic hydrocarbons in smoked food samples.

Accelerated solvent extraction (ASE) is a new sample extraction method offering a number of advantages such as low pe -extraction cost, reduced solvent and time consumption, and simplified extraction protocols. In this study, the ASE method was applied to the extraction of polycyclic aromatic hydrocarbons (PAHs) from biological samples. For recovery studies, fish tissues and ground pork were used as sample matrices. Sample aliquots fortified with 16 PAHs were extracted by ASE, and the extracts were treated with sulfuric acid and Florisil, followed by gas chromatography-mass spectrometry analysis. The PAH recoveries by the ASE method were found to be comparable with or better than those by Soxhlet extraction. The extraction and quantitation method was then applied to the determination of PAHs in several smoked meat samples obtained from a local market. Up to 12 PAHs were found to be present at concentrations ranging from 3 to 52 ng/g wet sample.

Treatment of acute bronchitis in adults. A national survey of family physicians.

BACKGROUND: The purpose of this study was to determine how family physicians in the United States treat acute bronchitis in an otherwise healthy adult. METHODS: A 33-item questionnaire on the diagnosis and treatment of acute bronchitis was mailed to a random sample of 500 physicians who are members of the American Board of Family Practice. RESULTS: Thirty-two of the 500 sampled physicians could not be located by mail; 265 of those who received the questionnaire responded. The response rate was 57% (265/468). Sixty-three percent of responding physicians indicated that antibiotics are their first choice of treatment for the otherwise healthy, nonsmoking adult with acute bronchitis. The decision to use antibiotics as the first choice of treatment did not vary by physician's sex, age, years in practice, practice location, practice type, or percentage of HMO patients. Only 6% of responding physicians reported using beta 2 agonist bronchodilators as their first choice of treatment. Physicians in this study stated that they prescribe an antibiotic 75% of the time in treating nonsmoking patients with acute bronchitis (first choice or otherwise). If the patient is a smoker, physicians reported that they prescribe antibiotics 90% of the time (F = 110.25; df = 1; P > .0001). Physicians reported that for patients who smoke it takes longer for coughs to totally resolve and longer for them to return to a normal activity level than for nonsmokers. CONCLUSIONS: Family physicians report that antibiotics are their most common treatment for acute bronchitis in the otherwise healthy adult. Previous clinical trials have shown only marginal improvement in symptoms when patients with this condition are treated with an antibiotic. With antibiotic resistance emerging as a major global health problem, it is essential that other methods of treatment be evaluated.

Diagnosis of acute bronchitis in adults: a national survey of family physicians.

BACKGROUND: The purpose of this study was to determine how family physicians in the United States diagnose acute bronchitis in otherwise healthy adults. METHODS: A 33-item questionnaire on the diagnosis and treatment of acute bronchitis was mailed to a random sample of 500 physicians who are members of the American Board of Family Practice. RESULTS: Two hundred sixty-five physicians responded. Of those who did not respond, 32 could not be located. Of those who did respond, 10 were either retired or were practicing in another specialty. The net response rate was 56% (255/458). Responding physicians stated that character of cough and sputum production are the most important items used in diagnosing acute bronchitis. Fifty-eight percent indicated that the cough should be productive, and 60% stated that the sputum should be purulent. Seventy-two percent of respondents did not feel that wheezing or rhonchi need to be present. Younger physicians and those who selected antibiotics as their first treatment choice were more likely to define acute bronchitis as the presence of a productive cough with purulent sputum (P < .05). Physicians from an academic setting were more likely to define acute bronchitis as a productive cough (P < .05). Thirty-six percent of physicians from practices serving populations with > or = 60% managed care patients included wheezing or rhonchi in the definition of acute bronchitis, compared with 26% of all others (P < .05). CONCLUSIONS: Variations in the diagnosis of acute bronchitis in otherwise healthy adults can be attributed to physician age, treatment choice, and practice setting. A significant number of family physicians did not require a productive cough as part of the diagnostic criteria for acute bronchitis. This finding needs to be considered in studies evaluating treatment. Additional qualitative studies are necessary to identify other factors involved in diagnosing acute bronchitis.

Haematology of conventionally-maintained Lac:P outbred Wistar rats during the 1st year of life.

Healthy Lac:P Wistar rats reached a plateau for red-cell parameters at about 18 weeks of age. For the next 9 months the values remained substantially constant. White-cell parameters varied in a more complex manner, and were largely unrelated to body-weight.

Variation in haematological parameters among inbred strains of rat.

Haematological determinations were carried out on 7 inbred strains of rats using a standardized procedure. Significant genetic variation was found for many of the parameters although none of the strains had values which could be termed pathological. Measurements also varied significantly from day to day. Factorial analysis of variance is shown to be a powerful method for the investigation of variation in haematological parameters.

A modified sedimentation method for counting platelets in blood.

A sedimentation method for counting human blood platelets is proposed which uses a fluid of sp.gr. i.057 at an osmolarity of 320 milliosmols. The fluid is a mixture of Lymphoprep and Isoton II. After centrifugation at about 200 platelets are counted on an electronic particle counter.

Suspension of non-viable fungal spores as a standard for platelet counting.

In the search among biological particles for a standard for counting human platelets, a strain of Absidia corymbifera was found to have spores that resembled platelets. After fixing in formalin and autoclaving the spores had a similar mean cell volume to that of human platelets. A suspension of these killed spores was tested in 100 laboratories and gave consistent results as a standard for human platelet counting. The Absidia corymbifera standard can be used in electronic counting methods but not in sedimentation methods, as the spores will be removed by centrifugation.

The cells of equine blood and their development.

Based on morphologie studies on bone marrow, lymphnode and blood preparations the cells of equine blood and their developmental stages are described and illustrated with 32 coloured photographs.