Attitudes Toward Weight Gain in Pregnancy

Recently, there has been increased interest in the influence of maternal prenatal nutrition on the course and outcome of pregnancy. Evidence has accumulated that a woman''s weight before pregnancy and the weight gained during pregnancy directly affect infant birth weight, incidence of neonatal mortality, and growth and development of the infant during the first year of life. Although recent recommendations for weight gain in pregnancy have been liberalized, a survey of 195 pregnant women who had prenatal visits in both clinic and private offices showed deficiencies in their understanding of the subject. Some 37 percent of women believed they should gain 20 pounds (9 kg) or less during pregnancy. Eight percent admitted to dieting before at least one antenatal visit and 54 percent thought their doctor would not be concerned about too little weight gained during pregnancy. This suggests that many women and some doctors are still ignorant of current concepts of proper nutrition during pregnancy. Apparently, increased lay and professional educational efforts are needed.     

Pathomorphological reactions and noradrenalin content of the heart after administration of depot angiotensin in trained and untrained rats

A 14-days' training of rats designed to adapt the animals to the procedure of blood-pressure measurement caused in the myocardium a decrease, in serum an increase in noradrenaline ( NA) content. The latter remained unchanged following 3 days of treatment with 2.5 mg depot angiotensin II (AII) but decreased by more than one-half in the myocardium of untreated animals, and increased in serum. Despite the considerable difference in myocardial NA content and blood-pressure behaviour, both trained and untrained rats showed the same morphological reactions following administration of A II. These myocardial alterations which largely correspond to the so-called epinephrine myocarditis should not therefore be due solely to NA action; rather, the involvement of A II should be considered also.     

Transnational Migration in Rural Oaxaca, Mexico: Dependency, Development, and the Household

Contradictory models of dependency and development have dominated the discussion of migration between Mexico and the United States. Transnational models of migration resolve these contradictions by defining a series of interdependencies (economy and society, for example). Using data collected in a rural Zapotec community in Oaxaca, Mexico, this article focuses on three areas: the stage-specific development of transnational movement; the domestic cycle, household decision making, and migration/remittance outcomes; and the changing nature of community participation. Rooting the discussion in household decision making captures the important role local social variability and economic dynamism play in understanding transnational processes and advancing migration studies. [ households, migration, transnationalism, dependency and development, Oaxaca, Mexico ]     

Food sharing: a model of manipulation by harassment

Most analyses of food-sharing behavior invoke complex explanationssuch as indirect and delayed benefits for sharing via kin selectionand reciprocal altruism. However, food sharing can be a moregeneral phenomenon accounted for by more parsimonious, mutualisticexplanations. We propose a game theoretical model of a generalsharing situation in which food owners share because it is in their own self-interest—they avoid high costs associatedwith beggar harassment. When beggars harass, owners may benefitfrom sharing part of the food if their consumption rate islow relative to the rate of cost accrual. Our model predictsthat harassment can be a profitable strategy for beggars if they reap some direct benefits from harassing other than sharedfood (such as picking up scraps). Therefore, beggars may manipulatethe owner's fitness payoffs in such a way as to make sharingmutualistic.     

Cytokeratin provides a specific marker for human arachnoid cells grown in vitro

Cells from cranial and spinal arachnoid membranes of humans were grown in culture. Their growth characteristics, morphology and details of their cytoskeletal composition are described. Arachnoid membranes, obtained at autopsy, were finely minced and incubated in tissue culture medium. Monolayers of cells of homogeneous morphology grew from these tissue fragments. The cells were flat and polygonal. They divided slowly to form non-overlapping monolayers of low cell density. Electron microscopic examination of cultured arachnoid cells revealed numerous desmosome-like tight junctions and abundant intermediate filaments (tonofilaments). Both morphological features are characteristic of arachnoid cells in situ, but not of cells in the fibroblast-rich dura mater. Immunofluorescence microscopy with monoclonal antibodies demonstrated cytokeratin in the cytoplasm of primary cultures of arachnoid cells. Thus we demonstrated that these cultured cells retained certain of the specific differentiated properties of arachnoid cells in situ and that they are not fibroblasts (which lack tight junctions and cytokeratins). To our knowledge, there have been no previous reports of in vitro growth of arachnoid cells. This in vitro model should be useful in studying the response of arachnoid cells to a variety of substances thought to be involved in the chronic inflammatory condition of the meninges known as arachnoiditis.     

Synthesis of thiol-functionalized N-acetylmuramyl peptide congeners suitable for their conjugation to target molecules

N-Acetylmuramyl-dipeptide and tripeptide derivatives containing at the C-terminus a masked thiol function, i.e. the S-tert-butylthiocysteamine residue, were synthesized via direct condensation of N-acetylmuramic acid with the peptide moiety using the dicyclohexylcarbodiimide/N-hydroxysuccinimide procedure. Reduction with tributylphosphine in aqueous organic media generates the free thiol function for a selective conjugation of these immunomodulants with target molecules via unsymmetrical disulfide bridging with a second thiol group by the sulfenohydrazide procedure or via thio-ether linkage by the addition to maleimido--or aziridine-derivatives.     

Membrane dynamics of lymphocyte interaction with antigen and tolerogen.

The principle of hapten-specific carrier-dependent immunologic tolerance was used to study the in vivo and in vitro interaction of lymphocyte membrane receptors with antigen (DNP-KLH) and tolerogen (DNP-MGG). Direct fluorescent techniques were employed to illustrate the binding of tolerogeu and antigen to the same population of lymphoid cells and the subsequent in vivo and in vitro events related to capping and regeneration of membrane receptors.     

Extensive variation in synonymous substitution rates in mitochondrial genes of seed plants

Background  

It has long been known that rates of synonymous substitutions are unusually low in mitochondrial genes of flowering and other land plants. Although two dramatic exceptions to this pattern have recently been reported, it is unclear how often major increases in substitution rates occur during plant mitochondrial evolution and what the overall magnitude of substitution rate variation is across plants.