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Biomedical subjects

M Senger

Publications and source records attributed to M Senger.

4 recordsLinked to original sources

[Effect of silver and copper ions on survival of Legionella pneumophila in tap water].

In vitro studies were performed to give information about the required metal concentrations in decontaminating Legionella-loaded warm water systems with the electrochemical generation of Ag+ and Cu2+ ions. The influence of Ag and Cu ions, as single compounds and in combination, on the survival of Legionella pneumophila (serogroup 6) was determined in tap water at 45 degrees C. Marked differences were detected in the action of these metals. Ag produced a much stronger inhibition than Cu. No additive effect was demonstrated when using Ag/Cu-combinations in the ratio of 1:10. In this case only the Ag-induced inhibition was detected. After 1 h of incubation at 45 degrees C a concentration of 80 + 800 micrograms/L Ag + Cu was needed to produce the maximal inhibitory effect (a 5 log decrease). An identical effect was seen after exposure to 20 + 200 micrograms/L Ag + Cu in the long-term action (24 h of incubation). The minimum inhibitory concentration after long-term incubation was 5 + 50 micrograms/L Ag + Cu. These metal concentrations produced a 1 log reduction. The in vitro results are discussed under consideration of earlier investigations after metering Ag and Cu into a Legionella-loaded water system and generated the following conclusions: In the beginning highly contaminated water systems at 45 degrees C need concentrations between 40 and 80 micrograms/L Ag + 400 to 800 micrograms/L Cu to kill Legionellas. After effective reduction of Legionella concentration of at least some logarithmic powers a slow constant maintenance concentration of 5 to 20 micrograms/L Ag + 50 to 200 micrograms/L Cu could be applied. At 22 degrees C the in vitro inactivation response is much lower. On the other hand in warm water systems with temperatures of 50 to 60 degrees C lower metal concentrations are sufficient.

Bacteriological Techniques

X-HUSAR, an X-based graphical interface for the analysis of genomic sequences.

Management and analysis of nucleotide and protein sequence and structure data constitute a traditional area of bioinformatics. Since the analytical programs are frequently developed by researchers, rather than software engineers, they tend to suffer from idiosyncratic and non-ergonomic man-machine interfaces. We report on HUSAR, our 140+ collection of third-party, as well as in-house developed or adapted, sequence manipulation and analysis tools, well integrated into the UNIX operating system environment and accessible via consistent menu-aware interface. Most of the HUSAR programs can be completely specified by UNIX command-line options; they can thus be run in batches or combined into pipes. Adding such a program into the HUSAR environment is almost a 'plug-and-play' exercise. HUSAR has been recently complemented with a graphical client interface, X-HUSAR, to support users on UNIX platforms with X11 windowing systems. The whole X-HUSAR interface is based on a single generic program, COMLIGEN, and a number of specific configuration files. COMLIGEN interprets those files and renders appropriate windows, menus, and other interactive elements, which help the end user in selecting application programs and specifying their options. Efforts of extending both HUSAR and X-HUSAR are roughly linear to the size of the collection.

Animals

Thyrotropin and prolactin responses to thyrotropin-releasing hormone in young men at high or low risk for alcoholism.

A reduced thyrotropin (TSH) response to TSH-releasing hormone (TRH) has been reported in a portion of abstinent alcoholic men without evidence of cirrhosis of the liver. It is not known whether this neuroendocrine change is a precursor of alcoholism or a sequelae of heavy alcohol consumption. Three of four published studies have found evidence for differences in TRH-induced TSH response in subjects at high risk for alcoholism, based on family history, compared with subjects at low risk for alcoholism. To test further the hypothesis that the TRH-induced TSH response is a vulnerability marker for alcoholism, we tested 25 young men with an alcoholic father [family history-positive (FHP)] and matched them, on alcohol consumption, to 25 young men with no identified first- or second-degree relatives with alcoholism [family history-negative (FHN)]. FHP subjects were further categorized based on whether their father had shown signs of alcohol problems before age 25 years (FHP-Early, n = 10) or after age 24 years (FHP-Late, n = 12). FHP subjects did not differ from FHN subjects in their baseline levels of thyroid hormones, glucose, cortisol, or TSH. However, the distribution of TSH responses in the FHP subjects was skewed toward lower values, compared with FHN subjects (p = 0.12). Furthermore, FHP-Late subjects had lower TSH responses than FHN subjects (p = 0.02), whereas the TSH response of FHP-Early subjects was not different from FHN subjects. Prolactin responses to TRH were similar across all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Prototype implementation of the integrated genomic database.

We aim to develop an open software system to handle human genome data. The system, called Integrated Genomic Database (IGD), will integrate information from many genomic databases and experimental resources into a comprehensive target-end database (IGD TED). Users will access front-end client systems (IGD FRED) to download data of interest to their computers and merge them with their own local data. FREDs will provide persistent storage of, and instant access to, retrieved data; a friendly graphical interface; tools for querying, browsing, analyzing, and editing local data; interface to external analysis; and tools for communicating with the outside world. The TED will be accessible over the network (online and offline) as a read-only resource for multiple clients. It collects data from major databases for nucleotide and protein sequences and structures, genome maps, experimental reagents, phenotypes, and bibliographic data, and sets of raw data produced at genome centers and laboratories. Beside character-based access via Gopher, WAIS, FTP, and several query language interfaces to the TED, we will develop a specialized front-end client, IGD FRED, with its own database manager, based on the ACEDB program. The FRED will support graphical display methods for sequence feature maps, chromosomal genetic and physical maps, and experimental objects like clone grids, etc. FRED will also provide an interface to important analysis software packages and tools for submitting data to external databases in their own format.

Computer Communication Networks