PubMed Health⌕ Search

Biomedical subjects

T Thiele

Publications and source records attributed to T Thiele.

7 recordsLinked to original sources
PubMed2002

Deltamethrin differentially affects neuronal subtypes in hippocampal primary culture.

The effects of deltamethrin on neuronal development and survival were studied using primary mouse hippocampal neurons in culture. Repeated applications of deltamethrin (between 2 nM and 2000 nM) decreased the number of neurons by 16-40%, respectively. Neuronal death was accompanied by an overall decrease of synaptic proteins. Deltamethrin treatment increased the K(+)-stimulated release of amino acid transmitters, GABA and glutamate. The release of the latter might also contribute to neuronal damage. A considerable number of neurons survived treatment with high concentrations of deltamethrin (200-2000 nM) and still displayed characteristics of mature neurons such as synaptic contacts or the expression of members of the Kv1 channel family. When analyzing subtypes of neurons calbindin- as well as somatostatin-positive neurons decreased by 50% after repeated treatment with 2 nM deltamethrin. Under the same conditions neuropeptide Y-positive neurons were up-regulated by 250%.Taken together these data show that deltamethrin at concentrations relevant in human toxicology differentially affects survival of neuronal subtypes by exerting either deleterious or supportive effects. We conclude that deltamethrin disturbs fine-tuning of neuronal efficiency in neuronal networks and might also interfere with the correct wiring during development.

Animals↗
PubMed1996

[Perioperative conjunctival flora].

BACKGROUND: The conjunctival flora is of great interest for each case of intraocular operation preventing postoperative infections. Despite of negative cultures before the operation we investigated in a prospective randomized study perioperatively the bacterial situation of the conjunctiva in 105 patients. MATERIAL AND METHODS: We took conjunctival swabs for microbiological examination from patient's eye operated on cataract or glaucoma, on the day of admission to the eye clinic and in the morning of the operating day. In addition, specimens were taken by nurses with Transwab MW-172 P before the local anaesthesia, disinfection of the conjunctiva and lids and application of eye drops, after these procedures by a research worker, at the end of the operation by the surgeon and two to three days after the operation by nurses with Transwab MW-172 P again. In 53 patients we collected lacrimal fluid to measure the lysozyme concentration. RESULTS: Out of 686 conjunctival swabs we have found 126 (18.4%) positive cultures. Staphylococcus epidermidis had the highest incidence (109 = 86.5%) followed by Staphylococcus aureus (7 = 5.5%). Only in 28 eyes all conjunctival swabs, taken at different times, were negative. There was an increase of positive cultures from routine swabs on the day of admission from 13 (12.4%), to 33 (31.7%) in the swabs taken on the day of the operation in the morning. On the other side the positive cultures decreased then continuously before and after the preparation of the operation, at the end of the operation and during two to three days postoperatively. There was'nt any statistical correlation between the concentration of the lacrimal lysozyme and the rate of positive cultures. CONCLUSION: The preoperative bacteriological diagnostic of the conjunctiva is important mainly for the prevention of postoperative endophthalmitis despite the transience and fluctuation of the conjunctival flora but also in case of endophthalmitis for rapid specific antibiotical therapy.

Adult↗
PubMed1990

Evidence for leukotrienes in animal venoms.

To elucidate further the pathomechanisms of cutaneous whealing in response to insect or sea-animal stings, commercial sources of bee and wasp venoms and of sea nettle nematocyst extracts, as well as crude bee and wasp venoms, were examined for the presence of histamine, leukotrienes (LT) C4, LTB4 (radioimmunoassay and reverse-phase high-pressure liquid chromatography), and neutrophil chemotactic activity (NCA). Histamine was present in all samples with the highest levels in the crude insect venoms. The same held for LTC4 with highest quantities in a liquid commercial bee venom extract and in the crude venoms. Relatively large amounts of LTB4 were recovered from the sea nettles with a correspondingly high NCA. Although small levels of LTB4 were found in the other samples, there was no clear correlation to the NCA on a quantitative basis. The demonstration of these mediators offers an explanation for the occurrence of local immediate and persistent wheals at sites of bee, wasp, and sea nettle stings in nonsensitized individuals.

Animals↗
PubMed1990

Immunoreactive leukotrienes in nettle plants (Urtica urens).

In order to clarify the mechanisms of urtication after contact with stinging plants, nettle (Urtica urens) hair and whole-plant extracts were examined for the presence of leukotriene (LT) B4 and LTC4 by reverse phase high-pressure liquid chromatography (RP-HPLC) and radioimmunoassay (RIA) and for in vitro neutrophil chemotactic activity and histamine contents. Both hair and plant extracts contained high levels of LTB4 and LTC4 by RIA as well as histamine. The presence of LTB4 was supported by RP-HPLC elution profiles and by in vitro chemotaxis. Nettle hairs therefore resemble insect venoms and cutaneous mast cells with regard to their spectrum of mediators.

Allergens↗
PubMedDate not supplied

Antecedent control of sleep-awakening disruption.

The sleep-awakening disruption of an adolescent with developmental disabilities was treated using an antecedent control intervention that identified his consistent time of wake-up, provided the presence of a preferred staff in his bedroom, and prompted social interaction from staff before challenging behaviors occurred. Positive findings were documented using a combined reversal and multiple baseline across settings design, with results maintained through a 9-month follow-up. A partial component analysis of the intervention plan suggested that the presence of preferred staff was the influential antecedent variable.

Adolescent↗