PubMed Health⌕ Search

Biomedical subjects

M Hoffmeister

Publications and source records attributed to M Hoffmeister.

6 recordsLinked to original sources
PubMed2006

Does a negative screening colonoscopy ever need to be repeated?

BACKGROUND AND AIMS: Screening colonoscopy is thought to be a powerful and cost-effective tool to reduce colorectal cancer incidence and mortality. Whether and when colonoscopy with negative findings has to be repeated is not well defined. The aim of this study was to assess the long term risk of clinically manifest colorectal cancer among subjects with negative findings at colonoscopy. PATIENTS: 380 cases and 485 controls participating in a population based case-control study in Germany. METHODS: Detailed history and results of previous colonoscopies were obtained by interview and from medical records. Adjusted relative risks of colorectal cancer among subjects with a previous negative colonoscopy compared with those without previous colonoscopy were estimated according to time since colonoscopy. RESULTS: Subjects with previous negative colonoscopy had a 74% lower risk of colorectal cancer than those without previous colonoscopy (adjusted odds ratio (aOR) = 0.26 (95% confidence interval, 0.16 to 0.40)). This low risk was seen even if the colonoscopy had been done up to 20 or more years previously. Particularly low risks were seen for sigma cancer (aOR = 0.13 (0.04 to 0.43)) and for rectal cancer (aOR = 0.19 (0.09 to 0.39)), and after a negative screening colonoscopy at ages 55 to 64 (aOR = 0.17 (0.08 to 0.39)) and older (aOR = 0.21 (0.10 to 0.41)). CONCLUSIONS: Subjects with negative findings at colonoscopy are at very low risk of colorectal cancer and might not need to undergo repeat colonoscopy for 20 years or more, if at all. The possibility of extending screening intervals to 20 years or more might reduce complications and increase the feasibility and cost-effectiveness of colonoscopy based screening programmes.

Adult↗
PubMed2002

Biochemistry and biotechnological applications of Gluconobacter strains.

The genus Gluconobacter belongs to the group of acetic acid bacteria, which are characterized by their ability to incompletely oxidize a wide range of carbohydrates and alcohols. The corresponding products (aldehydes, ketones and organic acids) are excreted almost completely into the medium. In most cases, the reactions are catalyzed by dehydrogenases connected to the respiratory chain. Since the reactive centers of the enzymes are oriented towards the periplasmic space, transport of substrates and products into, and out of, the cell is not necessary. Thus, rapid accumulation of incompletely oxidized products in the medium is facilitated. These organisms are able to grow in highly concentrated sugar solutions and at low pH-values. High oxidation rates correlate with low biomass production, which makes Gluconobacter strains interesting organisms for industrial applications. Modern fermentation processes, such as the production of L-sorbose (vitamin C synthesis) and 6-amino- L-sorbose (synthesis of the antidiabetic drug miglitol) are carried out with members of this genus. Other important products are dihydroxyacetone, gluconate and ketogluconates. The bacteria belonging to the genus Gluconobacter exhibit extraordinary uniqueness not only in their biochemistry but also in their growth behavior and response to extreme culture conditions. This uniqueness makes them ideal organisms for microbial process development.

1-Deoxynojirimycin↗
PubMed2001

An overview of endosymbiotic models for the origins of eukaryotes, their ATP-producing organelles (mitochondria and hydrogenosomes), and their heterotrophic lifestyle.

The evolutionary processes underlying the differentness of prokaryotic and eukaryotic cells and the origin of the latter's organelles are still poorly understood. For about 100 years, the principle of endosymbiosis has figured into thoughts as to how these processes might have occurred. A number of models that have been discussed in the literature and that are designed to explain this difference are summarized. The evolutionary histories of the enzymes of anaerobic energy metabolism (oxygen-independent ATP synthesis) in the three basic types of heterotrophic eukaryotes those that lack organelles of ATP synthesis, those that possess mitochondria and those that possess hydrogenosomes--play an important role in this issue. Traditional endosymbiotic models generally do not address the origin of the heterotrophic lifestyle and anaerobic energy metabolism in eukaryotes. Rather they take it as a given, a direct inheritance from the host that acquired mitochondria. Traditional models are contrasted to an alternative endosymbiotic model (the hydrogen hypothesis), which addresses the origin of heterotrophy and the origin of compartmentalized energy metabolism in eukaryotes.

Adenosine Triphosphate↗
PubMed1984

[Psychosocial consequences of cancer in a child for its parents and siblings].

Cancer in children leads to extreme situations not only for the child but for all members of the family. Fear of death quite often over years has severe psychosocial consequences for the sick child, its parents and siblings. Without sufficient help from the therapeutic team the family is usually not able, to cope with these problems.

Adolescent↗