Nutritional ecology and diachronic trends in Paleolithic diet and health

Modern nutritional studies have found that diverse diets are linked to lower infant mortality rates and longer life expectancies in humans. This is primarily because humans require more than fifty essential nutrients for growth and cell maintenance and repair; most of these essential nutrients must come from outside food sources rather than being manufactured by the body itself; and a diversity of food types is required to consume the full suite of essential nutrients necessary for optimal human health. These principles and their related affects on human adaptations and demography are the hallmarks of a theoretical paradigm defined as nutritional ecology. This essay applies concepts derived from nutritional ecology to the study of human evolution. Principles of nutritional ecology are applied to the study of the Middle‐to‐Upper Paleolithic transition in order to broadly illustrate the interpretive ramifications of this approach. At any stage in human evolution, those hominid populations that chose to diversify their subsistence base may have had a selective advantage over competitors who restricted their diet principally to one food type, such as terrestrial mammals.     

Soil management legacy alters weed-crop competition through biotic and abiotic pathways

Plant and Soil - Agricultural practices often have persistent effects on soil physicochemical properties and soil biota, which can feedback to influence plant performance. We investigated...     

Immunofluorescent staining of human metaphase chromosomes with monoclonal antibody to histone H2B

A mouse monoclonal IgM antibody against the core histone H2B has been shown, by indirect immunofluorescence, to stain metaphase chromosomes from a variety of cultured cell types. Experiments carried out with human HeLa cells showed that the intensity of staining varied along the length of chromosome arms giving in some cases a rudimentary banded staining pattern. Considerable variation in staining intensity was noted between individual chromosomes and between different metaphase spreads. It was noted that chromosomes having a more swollen appearance stained more intensely than those with a more compact structure, which were often unstained. Preincubation of unfixed metaphase chromosomes in buffered salt solutions virtually eliminated the cell to cell and chromosome to chromosome variation in staining, even when no visible effect on chromosome morphology was caused by such treatment. It is concluded that the determinant recognised by antibody HBC-7 is ubiquitous but is inaccessible in some chromosomes or chromosome regions. Digestion of purified chromatin (primarily interphase) with DNAase 1 or micrococcal nuclease resulted in a several-fold increase in the binding of antibody HBC-7 measured by solid-phase radioimmunoassay. This increase was abolished by subsequent treatment with trypsin, which suggests that the antigenic determinant recognised by antibody HBC-7 lies in the trypsin-sensitive N-terminal region of nucleosomal H2B. As the cationic N-terminal regions of the core histones are involved in DNA binding, it is likely that the accessibility of the determinant recognised by antibody HBC-7 is influenced by the relationship between the core histones and their associated DNA.     

Addition of Cryoprotectant Significantly Alters the Epididymal Sperm Proteome

Although cryopreservation has been developed and optimized over the past decades, it causes various stresses, including cold shock, osmotic stress, and ice crystal formation, thereby reducing fertility. During cryopreservation, addition of cryoprotective agent (CPA) is crucial for protecting spermatozoa from freezing damage. However, the intrinsic toxicity and osmotic stress induced by CPA cause damage to spermatozoa. To identify the effects of CPA addition during cryopreservation, we assessed the motility (%), motion kinematics, capacitation status, and viability of epididymal spermatozoa using computer-assisted sperm analysis and Hoechst 33258/chlortetracycline fluorescence staining. Moreover, the effects of CPA addition were also demonstrated at the proteome level using two-dimensional electrophoresis. Our results demonstrated that CPA addition significantly reduced sperm motility (%), curvilinear velocity, viability (%), and non-capacitated spermatozoa, whereas straightness and acrosome-reacted spermatozoa increased significantly (p < 0.05). Ten proteins were differentially expressed (two decreased and eight increased) (>3 fold, p < 0.05) after CPA, whereas NADH dehydrogenase flavoprotein 2, f-actin-capping protein subunit beta, superoxide dismutase 2, and outer dense fiber protein 2 were associated with several important signaling pathways (p < 0.05). The present study provides a mechanistic basis for specific cryostresses and potential markers of CPA-induced stress. Therefore, these might provide information about the development of safe biomaterials for cryopreservation and basic ground for sperm cryopreservation.     

Cell culture and in vitro studies of fresh and cryopreserved human insulinoma

Summary Dispersed cells from both fresh and cryopreserved human insulinoma have been maintained in cell culture. Initial yield of viable cells was 50% for fresh and 25% for cryopreserved tissue. Viability of cells in culture was documented by increasing numbers of cells (doubling time approximately 5 d initially and 2 d at the sixth subculture for both fresh and cryopreserved tissue) and continued release of insulin over time (approximately 100 ng/ml per 10⁵ cells at 10 d and 175 ng/ml per 10⁵ cells at 30 d of culture for both fresh and cryopreserved tissue). Evidence that cells growing in culture were beta cells was provided by: (a) recovery of intracellular and extracellular immunoreactive insulin (IRI), (b) electron microscopic morphology, and (c) immunohistochemical staining. Cells from fresh insulinoma incubated with increasing concentrations of extracellular glucose released increasing amounts of IRI up to approximately 15 mM glucose, which paralleled changes in plasma insulin obtained during a preoperative glucose tolerance test. Under an Intergovernmental Personnel Act Exchange from the Department of Surgery, University of California, Davis, Sacramento Medical Center.     

Glycosyl conjugates of biotinylated diaminopyridine applied for study of carbohydrate-to-carbohydrate interaction

Previous studies by us and others established that cell-cell adhesion is mediated by specific carbohydrate-to-carbohydrate interaction (CCI). Those previous studies were based on various biochemical and biophysical approaches, including the use of labeled glycosyl epitopes with fluorescent tag. However, these methods ideally require that the glycosyl epitope must be fixed to a solid phase molecule, preferably with multivalency. The purpose of the present study is to establish a CCI process using specific glycosyl residues conjugated to biotinylated diaminopyridine (BAP), and to observe: (i) clear occurrence of homotypic CCI between “Os Fr.B” having 5–6 GlcNAc termini, vs. absence of such homotypic CCI between “Os Fr.1” having 2 GlcNAc termini; (ii) occurrence of heterotypic CCI between GM3 ganglioside and Os Fr.B, vs. absence of such heterotypic CCI between GM3 and Os Fr.1. Interaction between Os Fr.B-BAP conjugate and Os Fr.B-ceramide mimetic (Os Fr.B-mCer) was demonstrated based on two experiments: (i) dose-dependent binding of Os Fr.B-BAP conjugate to polystyrene plates coated with Os Fr.B-mCer was observed in the presence of bivalent cation, a prerequisite for all CCI processes, and such binding was abolished by EDTA; (ii) binding between equal nanomolar Os Fr.B-BAP and Os Fr.B-mCer was inhibited by mM concentration Os Fr.B without conjugate, in dose-dependent manner. Thus, cell adhesion processes based on homotypic CCI between N-linked glycans having multiple GlcNAc termini, and heterotypic CCI between GM3 and such glycans, were clearly observed using BAP conjugates of glycosyl epitopes.     

Optimization of 2-piperidin-4-yl-acetamides as melanin-concentrating hormone receptor 1 (MCH-R1) antagonists: Designing out hERG inhibition

Herein, we disclose the discovery and optimization of 2-piperidin-4-yl-acetamide derivatives as MCH-R1 antagonists. Structural investigation of piperidin-4-yl-amide and piperidin-4-yl-ureas identified 2-piperidin-4-yl-acetamide-based MCH-R1 antagonists with outstanding in vivo efficacy but flawed with high affinity towards the hERG potassium channel. While existing hERG SAR information was employed to discover highly potent MCH-R1 antagonists with minimized hERG inhibition, additional hurdles prevented their subsequent clinical exploration.