Biomedical subjects

A Laine

Publications and source records attributed to A Laine.

96 records · Page 6Linked to original sources

PubMedDate not supplied

Electroencephalographic findings during experimental human exposure to m-xylene.

Aromatic hydrocarbon solvents, used widely in industry, cause central nervous system symptoms in exposed workers. Acute effects of m-xylene were studied in nine voluntary subjects exposed experimentally to stable or varying concentrations of m-xylene at rest or while exercising. Each subject participated in four exposure and two control sessions in a single-blind fashion. The time-weighted average (TWA) m-xylene concentration was always 200 parts per million (ppm) (8.2 mumol/l) during the 4-h exposure period, complying to a TWA of 4.1 mumol/l.8 h, which is equivalent to the hygienic limit allowed in work situations. The short-term peak concentrations were 400 ppm or less. Electroencephalography was recorded at the beginning of exposure, during exposure, and after exposure was stopped. Eighteen 60-s EEG samples for each subject on each experimental day were analyzed automatically. Exercise increased theta percentage and delta power and percentage; these changes were more prominent in the control session without exposure. Exposure increased the dominant alpha frequency and alpha percentage during the early phase of exposure and also counteracted the effects of exercise. The effects of short-term m-xylene exposure on EEG were minor, and no deleterious effects were noted. Perhaps alpha activation is indicative of stimulating and excitatory effects induced by m-xylene exposure, which has been noted heretofore in the absorption phase of alcohol intake.

Adult↗

PubMedDate not supplied

Validation of the microbiological methods hygicult dipslide, contact plate, and swabbing in surface hygiene control: a Nordic collaborative study.

A collaborative study on total aerobic bacterial count was conducted to validate the Hygicult TPC dipslide against contact plates and swabbing, using stainless-steel surfaces artificially contaminated with different microbes at various levels. Twelve laboratories took part in the validation procedure. The total number of collaborative samples was 108. The microbial level in each sample was assessed in triplicate using the 3 above-mentioned methods under 3 different incubation conditions (at 25 +/- 1 degrees C for 48 and 72 h and at 30 +/- 1 degrees C for 48 h). Surface sampling methods detached 25-30% at the lowest (theoretical yield, 1.4 cfu/cm2), 18-20% at the middle (theoretical yield, 10.7 cfu/cm2), and 16-21% at the highest (theoretical yield, 43.6 cfu/cm2) levels of microbes from the test surfaces. The percentage of acceptable results after removing outliers was 89%. Repeatability standard deviations ranged from 27.2 to 74.6% and reproducibility standard deviations ranged from 42.1 to 97.5%. There were no significant differences between results obtained at different incubation temperatures (25 and 30 degrees C) or incubation times (48 and 72 h) for all 3 methods. The Hygicult TPC dipslide, contact plate, and swabbing methods gave similar results at all 3 microbial levels tested: 0.35-0.43 cfu/cm2 at the lowest level, 1.9-2.2 cfu/cm2 at the middle level, and 7.1-9.1 cfu/cm2 at the highest level.

Algorithms↗

PubMedDate not supplied

Effect of conjugation on the biodistribution of 111In-labelled anti-PAP and anti-PSA monoclonal antibodies examined in nude mice with PC-82 human tumor xenografts.

The effect of conjugation on the biodistribution of 111In-labelled antibodies was studied in nude mice carrying human prostatic cancer xenografts (PC-82). Two monoclonal antibodies and their fragments raised against human prostate-specific acid phosphatase (PAP) and prostate-specific antigen (PSA) were used. We used the cyclic anhydride of DTPA (CA-DTPA) as a chelating agent, or, alternatively, 1-(p-aminobenzyl)diethylenetriaminepentaacetic acid (NH2-Bz-DTPA) was attached as a linker to the carbohydrate components of the parent molecules. The conjugation method, the amount of circulating antigen and the size of the antibody component affected the blood clearance of the labelled derivatives. F(ab')2 fragments displayed a faster blood clearance than the corresponding derivatives of intact IgG1s. Aminobenzyl derivatives of anti-PAP-IgG1 showed a faster blood clearance than the corresponding CA-DTPA derivatives, but, in the case of derivatives of anti-PSA-IgG1, this was less clear, possibly due to the high PSA concentrations in the mouse sera. All the derivatives studied accumulated in the liver independently of the size of the antibody derivative, most probably due to the formation of antigen-antibody complexes. All CA-DTPA derivatives showed a higher kidney accumulation than the corresponding aminobenzyl derivatives. CA-DTPA-anti-PAP-F(ab')2 fragments showed a higher kidney uptake than the corresponding anti-PSA-F(ab')2 derivatives, since a large fraction of the latter are complexed with circulating antigen, thereby slowing down its reabsorption by the kidney. In addition, the lower kidney accumulation for anti-PSA-F(ab')2 fragments might be, at least partly, due to the electronegative charge of the molecule.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗

PubMedDate not supplied

[The protein constituents of human bronchial washings. Their relationship to the defenses of the respiratory tract (author's transl)].

In an attempt to define the composition of normal bronchial secretions, bronchial washings were obtained from normal areas of the lung in six patients. An analysis of proteins in the washings was carried out by crossed immunoelectrophoresis. The proteins detected were derived mainly from plasma and a very low content of secretory proteins was found. The composition of bronchial secretions and bronchial washings from a bronchitic patient was established and compared by crossed immunoelectrophoresis and gel filtration. The most important components were IgA, alpha1-antichymotrypsin and alpha1-antitrypsin, all of which are defense factors for the respiratory tract.

Blood Proteins↗

PubMedDate not supplied

[Proteins and enzymes in normal human bronchial washing fluids (author's transl)].

Six normal subjects, two of whom were heavy smokers, underwent broncho-alveolar and bronchial washings. The aim of our work was to compare the biochemical composition of these fluids. Quantitative measurements of total protein, IgG AND IgA were made, the percentage of IgA 7S among the IgA population was established, an immunoelectrophoretic study was carried out, and glycosidase and protease activities were determined. In a given subject, the bronchial washing always showed more IgA, 11S and more concentrated glycosidase activities than the broncho-alveolar washing; the latter had higher values for IgG and protease activities, the most important being chymotrypsin-like activity. In both fluids, IgA 11S represented the main part of IgA population.

Adult↗

PubMedDate not supplied

Comparison of three methods for protein measurement: application to bronchoalveolar lavage fluids.

The protein contents of bronchoalveolar lavage fluids from normal subjects and patients were estimated by three methods: LOWRY's assay, Coomassie blue method and the automatic laser nephelometric assay. The assays were carried out with native fluids and human serumalbumin as the standard. The lowest values were usually obtained with the dye-binding method. The best correlation coefficients between the assays were obtained from the pulmonary lavage of patients.

Bronchi↗