The role of nutrition on epigenetic modifications and their implications on health

Nutrition plays a key role in many aspects of health and dietary imbalances are major determinants of chronic diseases including cardiovascular disease, obesity, diabetes and cancer. Adequate nutrition is particularly essential during critical periods in early life (both pre- and postnatal). In this regard, there is extensive epidemiologic and experimental data showing that early sub-optimal nutrition can have health consequences several decades later.     

Resistance to the peptide-like antibiotic negamycin in Escherichia coli

An $\text{Escherichia coli}$ mutant resistant to the peptide-like antibiotic negamycin carries a mutation, NEG40, which maps at minute 65 on the bacterial genome. Termination of protein synthesis, which is normally blocked by negamycin in wild type cellular extracts, continues with cellular extracts from the mutant in the presence of the drug; indeed, release of complete peptides from the polysomes still proceeds over a wide range of drug concentrations. The data suggest that the NEG40 mutation affects one of the components of the termination complex (ribosome or release factor).     

Isolation and sequence of a tropomyosin-binding fragment of turkey gizzard calponin

Limited chymotryptic cleavage of turkey gizzard calponin yields a 13 kDa fragment which could be purified by its ability to bind to Sepharose-immobilized tropomyosin. This 13 kD polypeptide is shown to be derived from a 22 kDa fragment. Complete amino acid sequence analysis of the 13 kD and 22 kD fragments reveals high homology with the formerly characterized smooth muscle-specific protein SM22 alpha (Pearlstone, J.R., Weber, M., Lees-Miller, J.P., Carpenter, M.R. and Smillie L.B., 1987, J. Biol. Chem. 262, 5985-5991) and the product of gene mp20 of Drosophila (Ayme-Southqate, A., Lasko, P., French, C, and Pardue, M.L. [(1989) J. Cell Biol. 108, 521-531]. Futhermore we recognize sequence elements of a putative actin-binding domain of alpha-actinin, the calpactin I or p 36 sequence, and a consensus motif present in the repeats of the gene product of the candidate unc-87 gene of C. elegans (S.D. Goetinck and R.H. Waterston, personal communication).     

Long-term effects of dietary isoflavones on uterine gene expression profiles

Isoflavones (ISOs) are bioactive food ingredients of the traditional East Asian diet and currently discussed as alternatives to classical hormone replacement therapies and for reducing the prevalence of hormone-dependent cancers. Although there are many studies on ISOs, not much is known about their long-term effects.Therefore, we performed an animal experiment analyzing the effects of three different diets: a phytoestrogen-free diet, a diet supplemented with genistein (700 μg/g diet) and an ISO-high diet (232 μg daidzein and 240 μg genistein/g) at two distinct time points, juvenile (21 days) and adult (97 days). Exposure started prior to mating of the parents and throughout the life of the offspring.We observed a stronger increase of uterine wet weights in juvenile offspring with genistein exposure (1018 ± 350 mg/kg BW) than with ISO-high diet (497 ± 133 mg/kg BW). Whereas the expression of proliferation related genes (PCNA; Ki67; IGF-1; IGF-1R), analyzed by real-time-qPCR and Western blot, were significantly down-regulated in juvenile animals exposed to genistein. Additionally, genistein exposure led to estrogenic responses, observed upon increase of complement C3 and decrease of estrogen receptors gene expressions, while the exposure to ISO-high diet did not show these effects.In conclusion, both the time point on which phytoestrogen exposure starts together with the composition of the ingested phytoestrogen containing diet are of great importance for the biological response of the offspring.     

Ribosomal assembly deficiency in an Escherichia coli thermosensitive mutant having an altered L24 ribosomal protein.

Localized P1 mutagenesis was used to screen for conditionally lethal mutations in ribosomal protein genes. One such mutation, 2859mis, has been mapped inside the ribosomal protein gene cluster at 72 minutes on the Escherichia coli chromosome and cotransduces at 98% with rpsE (S5). The 2869mis mutation leads to thermosensitivity and impaired assembly in vivo of 50 S ribosomal particles at 42 °C. The strain carrying the mutation has an altered L24 ribosomal protein which at 42 °C shows weaker affinity for 23 S RNA than the wild-type protein. The mutational alteration involves a replacement of glycine by aspartic acid in protein L24 from the mutant. We conclude therefore that the 2859mis mutation affects the structural gene for protein L24 (rplX).     

Assessment of Optimal Selected Prognostic Factors

The identification and assessment of prognostic factors is one of the major tasks in clinical research. The assessment of one single prognostic factor can be done by recently established methods for using optimal cutpoints. Here, we suggest a method to consider an optimal selected prognostic factor from a set of prognostic factors of interest. This can be viewed as a variable selection method and is the underlying decision problem at each node of various tree building algorithms. We propose to use maximally selected statistics where the selection is defined over the set of prognostic factors and over all cutpoints in each prognostic factor. We demonstrate that it is feasible to compute the approximate null distribution. We illustrate the new variable selection test with data of the German Breast Cancer Study Group and of a small study on patients with diffuse large B‐cell lymphoma. Using the null distribution for a p‐value adjusted regression trees algorithm, we adjust for the number of variables analysed at each node as well. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Paternal inheritance of chloroplast DNA in Larix

Restriction enzyme analysis was used to determine the inheritance of chloroplast DNA in conifers. The plant material studied included five individual trees of European larch (Larix decidua Mill.) and Japanese larch (Larix leptolepis Sieb. & Zucc.) and six hybrids from controlled crosses between these species. The chloroplast DNA fragment patterns generated by Bam-HI and Bcl-I were species-specific. Paternal inheritance of chloroplast DNA patterns was found in most Larix crosses. One hybrid showed maternal chloroplast DNA patterns. In addition, two other hybrids had mixed Bam-HI patterns suggesting recombination between maternal and paternal chloroplast DNA. The mechanisms favoring paternal inheritance in conifers are not known. Paternal inheritance of chloroplast DNA is suggested it to be a general phenomenon in conifers.     

Volume estimation of biological objects by systematic sections

The absolute volume of biological objects is often estimated stereologically from an exhaustive set of systematic sections. The usual volume estimator is the sum of the section contents times the distance between sections. For systematic sectioning with a random start, it has been recently shown that is unbiased when m, the ratio between projected object length and section distance, is an integer number (Cruz-Orive 1985). As this quantity is no integer in the real world, we have explored the properties of in the general and realistic situation m . The unbiasedness of under appropriate sampling conditions is demonstrated for the arbitrary compact set in 3 dimensions by a rigorous proof. Exploration of further properties of for the general triaxial ellipsoid leads to a new class of non-elementary real functions with common formal structure which we denote as np-functions. The relative mean square error (CE ²) of in ellipsoids is an oscillating differentiable np-function, which reduces to the known result CE ²= 1/(5m ⁴) for integer m. As a biological example the absolute volumes of 10 left cardiac ventricles and their internal cavities were estimated from systematic sections. Monte Carlo simulation of replicated systematic sectioning is shown to be improved by using m instead of m . In agreement with the geometric model of ellipsoids with some added shape irregularities, mean empirical CE was proportional to m ^–1.36 and m^–1.73 in the cardiac ventricle and its cavity. The considerable variance reduction by systematic sectioning is shown to be a geometric realization of the principle of antithetic variates.     

Auto anti-A1 and auto anti-NA1 after bone marrow transplantation

The production of auto anti-A1 and auto anti-NA1 antibodies in patient with aplastic anemia has been described. The patient of group A1 received bone marrow from his brother of group A2. For immunosuppression cyclosporine A was administered.