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Biomedical subjects

S Heidrich

Publications and source records attributed to S Heidrich.

9 recordsLinked to original sources
PubMed2003

Groundwater pollution and remediation options for multi-source contaminated aquifers (Bitterfeld/Wolfen, Germany).

Large-scale contaminated megasites like Bitterfeld/Wolfen in the eastern part of Germany are characterized by a regional pollution of soil, surface water and groundwater due to the long and varied history of the chemical industry on location. The pollutants in groundwater may spread to uncontaminated areas and endanger receptors like surface water and drinking water wells according to the site-specific hydrologic regime. In addition, the sheer extension of the contamination at megasites as well as the existence of large densely populated areas and land of high-reuse value prevent a simple risk management strategy of use restriction for the whole area. Since a complete clean-up of the groundwater on a megasite is neither economically feasible nor technically possible within a reasonable time-frame, a multi-approach remediation strategy is needed, taking into account the immediate risks for human health, ecosystem and so-called "protectable goods". Moreover, the contaminants at megasites typically represent a dangerous cocktail of multiple harmful substances stemming from a variety of sources, which may interact with each other and complicate the search for an appropriate remediation strategy. At the SAFIRA-project site in Bitterfeld approaches for in situ remediation of multiple contaminants in groundwater are being tested. Alternatives in local implementation strategies as well as consequences of long-term restrictions for megasites like Bitterfeld need an independent evaluation of the situation using a risk-based approach. For this reason, a GIS-based 3D model of the area including geology, contaminants, hydrogeology, land-use and protected areas has been built. The regional groundwater pollution is characterized by contamination profiles of all monitored substances. In the area of investigation, e.g. threefold and fourfold threshold levels of chlorinated methane, ethane and ethene as well as HCH-isomers, mono-, di- and tetrachlorobenzene, DDT-isomers and benzene are frequently detected in groundwater, that means in at least 60% of the wells that were sampled. High median values of more than 10 microg/l were calculated for cis/trans-1,2-dichloroethene, 1,2-dichloroethane, chloroethene and monochlorobenzene. In general, the regional distribution of contaminants reflect the different sources and pathways, and give first results from a regional point of view, depending on a land-use classification of specific areas.

Chemical Industry↗
PubMed1999

IFN-gamma is only partially restored by co-stimulation with IL-12, IL-2, IL-15, IL-18 or engagement of CD28.

BACKGROUND: Although it is well established that T cells derived from patients with atopic diseases produce low levels of interferon-gamma (IFN-gamma), the mechanisms responsible for this phenomenon are poorly understood. OBJECTIVES: To elucidate whether IFN-gamma production may be restored by co-stimulatory molecules known to increase IFN-gamma production in vitro. Further, to investigate whether deficient IFN-gamma production is associated with disease activity. METHODS: Purified peripheral T cells obtained from patients with severe atopic dermatitis (AD), individuals with a history but no symptoms of AD and healthy control subjects were activated with anti-CD3 MoAbs in the presence or absence of anti-CD28 MoAbs, interleukin (IL-) 12, IL-2, IL-15 or IL-18. IFN-gamma production was determined at the single cell level by flow cytometry, as well as by ELISA. RESULTS: Activated T cells from patients with severe AD produced less IFN-gamma than T cells from healthy control individuals. IL-12 or engagement of CD28 enhanced IFN-gamma production in both healthy and atopic T cells. However, absolute values of IFN-gamma were still different. IL-2, IL-15 and IL-18 did not restore IFN-gamma production. T cells from individuals with a history of AD produced more IFN-gamma than those from subjects with severe AD, but less than T cells from healthy individuals. Atopic T cells expressed regular levels of CD3, CD28 and Stat4, the main signal transducer and activator of transcription for IL-12. IL-4, IL-10 and TGF-beta production by T cells were not different between healthy and atopic individuals. CONCLUSION: IFN-gamma deficiency in atopic T cells is not due to a lack of responsiveness to CD28, IL-12, IL-2, IL-15 or IL-18. T cell-derived cytokines able to antagonize IFN-gamma do not contribute to decreased IFN-gamma production. The extent of IFN-gamma deficiency seems to be dependent on disease activity.

Adolescent↗
PubMed1999

Mechanisms of deficient interferon-gamma production in atopic diseases.

BACKGROUND: The mechanisms responsible for an imbalanced cytokine response in atopic diseases are still not understood. While impaired interferon-gamma (IFN-gamma) production may be the result of a pathological T-cell/antigen-presenting cell (APC) interaction, evidence was provided that the T cell itself may have an intrinsic defect to produce IFN-gamma. OBJECTIVE: To clarify whether impaired IFN-gamma production by T cells from patients with atopic dermatitis (AD) represents an intrinsic defect in producing IFN-gamma. METHODS: Effector T cells were generated from CD4+ CD45RA+-naive precursors from patients with AD and healthy control individuals by activation with anti-CD3+ anti-CD28 MoAbs. Following restimulation, IFN-gamma production was measured by ELISA and flow cytometry. RESULTS: IFN-gamma production by atopic T cells was decreased compared with healthy T cells. IL-12 present at priming or high doses of IL-2 during the culture period, even in the absence of IL-12, completely restored IFN-gamma production. Conversion of naive CD45RA+ to CD45R0+ effector cells did not differ between atopic and healthy donors' T cells. CONCLUSION: Impaired IFN-gamma production by T cells from atopic individuals is not the result of an intrinsic, genetically fixed, defect to produce sufficient amounts of IFN-gamma. The data provides evidence that correction of an impaired TH1 response in AD may be successful at the precursor T cell level.

Adolescent↗
PubMed1994

The self, health, and depression in elderly women.

A short-term, longitudinal, survey study was conducted to examine relationships among actual and ideal self conceptions, physical health, and depression in 149 community-dwelling elderly women. Two theoretical perspectives regarding the self were compared, women's self-development and lifespan developmental theory. As predicted by theories of women's development, relationships with other emerged as a salient aspect of the self in elderly women. Regression analyses indicated that actual and ideal self-conceptions were predicted by depression, but not generally by physical health status. Thus, physical health problems were not global in their effects on the various dimensions of the self in elderly women, but depression was.

Age Factors↗
PubMed1989

Factors women take into account when deciding upon type of surgery for breast cancer.

For women with stage I or II breast cancer, randomized trials have demonstrated no significant difference in survival rates between women receiving modified radical mastectomy (MRM) and women receiving breast conserving (BC) surgery. Therefore, many women are now in a position of having a choice between these two options. Twenty-two women who met the surgical criteria for having this choice were interviewed 1 to 2 weeks postsurgery to determine factors they had considered when deciding between MRM and BC, how much they wished to participate in decision-making, and the sources of information they used. The sample was purposefully limited to women attending one clinic in order to insure control over variables such as the information to which patients are exposed. When asked why they had chosen a given surgery, two factors, concerns about radiotherapy (p = 0.003) and body integrity (p = 0.04), emerged as significantly different for women choosing BC vs. MRM. Furthermore, women reported that participation in decision-making was important to them and that they had had sufficient participation in the decision-making process. Finally, they rated "people" sources of information as more important than written or visual materials, suggesting that nurses and other care providers are important in supporting women through the decision-making process.

Adult↗
PubMed1978

[Cryoprotective ability of glycerin and DMSO in the deep freezing of dog sperm].

The sperm-bearing fractions of 163 ejaculates collected from 6 Beagles aged two years were used to test the cryoprotective effect of DMSO and glycerol in deep freezing investigations. It could be shown that the cryoprotective capacity of glycerol was better than the one of DMSO. Glycerol should rather be added to the sperms at + 5 degrees C than at + 25 degrees C. The best preservation results were achieved by a combined addition of DMSO and glycerol under the following conditions: time of cooling down to +5 degrees C of the extended sperm fractions 50 minutes, final concentration of DMSO 1% (max.), final concentration of glycerol 8% (max.), glycerol equilibration time 30 minutes.

Animals↗
PubMed1978

[The spermatogenetic capacity of male beagles].

Daily, weekly and twice a week sperms were collected from 4 eighteen month aged Beagles for spermatologic and spermatogenetic examinations. The spermatologic results of 260 ejaculates showed in all parameters great differences. Sperm collection which were done twice a week showed a higher total amount of sperms than the daily and weekly collected ejaculates. Daily sperm collections taken over more than three weeks did not lead to a decreasing libido sexualis and were qualified for the evaluation of the daily sperm production ability of dogs.

Animals↗