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J Jäger

Publications and source records attributed to J Jäger.

At least 55 records · Page 3Linked to original sources
PubMed1983

Criteria for the standardization of Salmonella mutagenicity tests: results of a collaborative study. II. Studies to investigate the effect of bacterial liquid culture preparation conditions on Salmonella mutagenicity test results.

The influence of various parameters and growth conditions in the "overnight culture" of Salmonella typhimurium strains on mutagenicity test results was investigated. A number of factors were first suspected to be of some importance for the quantitative outcome of the mutagenicity test. None of them, however, was found to influence the results to such a marked extent as to be a major source of variability. Only the brand of nutrient broth used for the propagation of the bacteria proved finally to have a certain effect on the number of (spontaneous and induced) revertant colonies, although no precise and quantitative statements can be made with regard to a possible standardization of this experimental segment in the Salmonella mutagenicity test. The occurrence of such unpredictable but noticeable influences is, however, evidence for the importance of an intralaboratory optimization and standardization of all parts of the test procedure.

Animals↗
PubMed1982

[Cytologic picture of florid pulmonary tuberculosis in bronchial aspirates].

In 24 patients suffering from florid pulmonary tuberculosis we found a fairly characteristic cytologic pattern in smears from aspiration material yielded by bronchoscopy. Besides elements of specific granulation tissue, histiocytes, alveolar macrophages and squamous cells of metaplastic origin a high proportion of specimens exhibited a slightly detritic background rich in leucocytes, containing clusters of respiratory epithelial cells with reactive appearance. The significance of this pattern for suspicion of tuberculosis is emphasized. The diagnosis may be proved by evidence of acid fast bacilli in cytologic smears.

Bronchi↗
PubMed1981

Habituation of the vestibulo-ocular reflex (VOR) in the monkey during sinusoidal rotation in the dark.

In experimentally naive monkeys the horizontal vestibulo-ocular-reflex (VOR) has a time constant which is in the range of 40--60 s. It can be measured as the nystagmus decline after pulses of angular acceleration, or from the transfer functions obtained from sinusoidal rotation with different frequencies. When frequencies below 0.1 Hz are applied, sinusoidal rotation leads to a pronounced phase advance, a decrease in gain and a shortening of the pre- and post-rotatory nystagmus time constant. Even very low frequencies (e.g., 0.002 Hz) are effective where the phase advance of eye relative to head velocity is already 90 degrees in the naive animal. Exposing the animal to stimulation only at a single frequency shifts the whole frequency curve towards a greater phase advance. These results are consistent with habituation experiments in which steps of angular velocity have repeatedly been applied. In these experiments nystagmus duration is shortened, whereas the initial response at the end of acceleration does not change. This corresponds to a phase shift and a gain reduction in the low frequency range (below 0.1 Hz) which we have also observed during sinusoidal rotation.

Animals↗
PubMed1981

Vestibular habituation in man and monkey during sinusoidal rotation.

Habituation of the vestibular system by repeated steps of angular velocity leads to a shortening of nystagmus. These steps can be broken down into different frequency sinusoids. High-frequency sinusoidal rotation (above 0.1 Hz) generally was found to be ineffective, while low-frequency stimulation (0.0015-0.05 Hz) led to a dramatic shortening of time constants after only a few cycles of stimulation. In the alert monkey, time constants of vestibular nystagmus and single units, recorded from the vestibular nuclei, are always similar and covary together. Experiments in humans, with measurement of nystagmus and subjective velocity sensation, suggest similar processes for habituation.

Acceleration↗
PubMed1981

[Results of the morphological diagnosis of bronchial carcinoma by biopsy in a lung disease clinic].

An analysis of the morphological diagnosis is made in all 339 consecutive patients suffering from lung cancer and received in our clinic in 1979. Including the non-endoscopically examined cases the tumour has been proved morphologically in 88% of central carcinomas, in 81% of the intermediary type and in 47% of peripheral ones. As for the endoscopically examined patients 93% of the central tumours and 48% of the peripheral ones were morphologically assured. Coincidence between histological and cytological type was found in 83% out of 58 resected tumours. The diagnostic efficacy of the bronchial secretion and of the material obtained by catheterbiopsy is investigated in dependence on different tumour-localisations. Furthermore the value of transthoracic needle-biopsy in cases of peripheral carcinomas is assessed.

Biopsy↗
PubMed1980

Reaction of solid carrier-adsorbed polycyclic aromatic hydrocarbons with gaseous low-concentrated nitrogen dioxide.

The interaction of gaseous NO2 with solid carrier-adsorbed polycyclic aromatic hydrocarbons was studied under laboratory conditions with a specific attention to factors that might possibly influence this reaction, such as type of carrier lighting conditions, NO2 concentration, exposure time, and temperature. At the NO2 concentration of 1.33 ppm there were detected the following nitro derivatives: nitroanthracene, nitropyrene, nitrochrysene, two mononitro derivatives of benzo/a/pyrene, and dinitrobenzo/a/pyrene. The experimental data suggest that the formation of nitroaromates in atmospheric environment is to be expected, provided that there are present, besides polycyclic aromatic hydrocarbons and nitrogen oxides, also suitable types of sorbents, such as silica gel or fly ash.

Air Pollutants↗
PubMed1977

[The value of sputum cytodiagnosis as a screening method for lung cancer detection--results of a study (author's transl)].

In the course of a screening program for lung cancer detection which has been going on for several years, 2432 male risk persons, aged 42-67, were examined cytologically in 1974 and 1975. The annual rate of incidence of lung cancer in this population is unknown. We estimate it at 3-4%. From two sputa of each patient we screened one specimen. 24.7% of the sputa were unsatisfactory. In the remaining preparations there were neither tumor cells nor cells suspicious for cancer. This result is discussed in view of the experiences of other authors, that the sensitivity of cytological screening for lung cancer is 33-38%. Recommendations are given for increasing the number of detected cases.

Adult↗