Vitamin D and intestinal calcium absorption.

The principal function of vitamin D in calcium homeostasis is to increase calcium absorption from the intestine. Calcium is absorbed by both an active transcellular pathway, which is energy dependent, and by a passive paracellular pathway through tight junctions. 1,25Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) the hormonally active form of vitamin D, through its genomic actions, is the major stimulator of active intestinal calcium absorption which involves calcium influx, translocation of calcium through the interior of the enterocyte and basolateral extrusion of calcium by the intestinal plasma membrane pump.

Preferential development of Th17 cells in offspring of immunostimulated pregnant mice.

Pregnant mice were stimulated at day 12 of gestation with the nucleotide poly(I:C). At 24h after stimulation, serum levels of maternal cytokines were measured, and at postnatal ages 2 and 3 weeks, offspring were analyzed for T helper (Th) cell subsets. Lymphocytes from offspring of poly(I:C)-injected (vs.

Effects of nonsteroidal anti-inflammatory drugs on flexor tendon adhesion.

Purpose: Besides its anti-inflammatory effects, nonsteroidal anti-inflammatory drug therapy may affect tendon healing and the development of peritendinous adhesions. The purpose of this study was to compare the effect of nonselective (ibuprofen) and COX-2 selective (rofecoxib) nonsteroidal anti-inflammatory drugs on the adhesion formation after tendon repair.

Methods: We assigned 67 rabbits to one of 3 (placebo, ibuprofen, or rofecoxib) groups.

Recombinant human platelet-derived growth factor BB (rhPDGF-BB) and beta-tricalcium phosphate/collagen matrix enhance fracture healing in a diabetic rat model.

Diabetes mellitus is a common systemic disease that has been associated with poor fracture healing outcomes. The mechanism through which diabetes impairs bone regeneration is unknown. One possible mechanism may be related to either decreased or uncoordinated release of local growth factors at the fracture site.

Comparison of fracture healing among different inbred mouse strains.

Quantitative trait locus analysis can be used to identify genes critically involved in biological processes. No such analysis has been applied to identifying genes that control bone fracture healing. To determine the feasibility of such an approach, healing of femur fractures was measured between C57BL/6, DBA/2, and C3H inbred strains of mice.

CpG oligodeoxynucleotide-induced immunity prevents growth of germinal center-derived B lymphoma cells.

Therapeutic efficacy of CpG oligodeoxynucleotide (ODN) ISS 1018 was tested in a murine B cell lymphoma model. Previous studies showed that the B lymphoma cells of SJL mice stimulate vigorous proliferation of host CD4(+) TH cells that is unaccompanied by development of tumor-specific CTL. In the presence of ISS 1018, however, tumor cells stimulated high levels of CTL activity in vitro, and this cytotoxic activity was inhibited when anti-IL-12 mAb was added to the cultures.

Mefloquine selectively increases asynchronous acetylcholine release from motor nerve terminals.

Effectiveness against chloroquine-resistant Plasmodia makes mefloquine a widely used antimalarial drug. However, mefloquine's neurologic effects offset this therapeutic advantage. Cellular actions which might contribute to the neurologic effects of mefloquine are not understood.

Mefloquine inhibits cholinesterases at the mouse neuromuscular junction.

Mefloquine is effective against drug-resistant Plasmodium falciparum. This property, along with its unique pharmacokinetic profile, makes mefloquine a widely prescribed antimalarial drug. However, mefloquine has neurologic effects which offset its therapeutic advantages.

Determination of variations in gene expression during fracture healing.

The genetic make-up and physiological state of a cell or tissue in an organism interact to determine the level at which specific genes are expressed. Identifying genes differentially expressed between 2 genetic or physiological states often gives insight into the molecular mechanisms controlled by the process in question. Various methods have been devised to identify differentially expressed genes and to quantify the expression of differentially regulated genes at the RNA or protein level.

Termination of lifespan of SV40-transformed human fibroblasts in crisis is due to apoptosis.

Normal human fibroblasts in culture have a limited lifespan, ending in replicative senescence. Introduction of SV40 sequences encoding large T antigen and small t antigen into pre-senescent cells results in an extension of lifespan for an additional 20-30 population doublings. Rare clones of SV40-transformed cells are capable of indefinite growth and are described as immortal; however, the great majority of SV40-transformed cells terminate this extended lifespan in cell death, termed "crisis.

Requirement for reverse immune surveillance for the growth of germinal center-derived murine lymphomas.

The concept of reverse immune surveillance, first conceived over 12 years ago, described the relationship that existed between germinal center-derived B cell lymphoma cells and the host immune system in SjL/J mice. According to reverse immune surveillance, recognition of tumor cell antigens and a response by the host immune system is required for tumor growth. The phenomenon of reverse immune surveillance related to B cell lymphomas has recently also been characterized in another inbred mouse strain, C57L/J.

Isolation and characterization of pleurocidin, an antimicrobial peptide in the skin secretions of winter flounder.

Antimicrobial peptides are found in both myeloid cells and mucosal tissues of many vertebrates and invertebrates. These peptides are predicted to operate as a first-line host defense mechanism exerting broad-spectrum activity against pathogenic bacteria, fungi, parasites, and enveloped viruses. We report the characterization of a novel 25-residue linear antimicrobial peptide found in the skin mucous secretions of the winter flounder (Pleuronectes americanus).

GRSF-1: a poly(A)+ mRNA binding protein which interacts with a conserved G-rich element.

Computer predictions identified similarities to a 14-base G-rich element in numerous mRNAs at a variety of locations. A Northwestern screening strategy was used to obtain a cDNA clone from a HeLa cell library using the G-rich RNA element as a probe. A cellular protein (called GRSF-1), which was encoded by this cDNA, binds RNAs containing the G-rich element.

Somite Chondrogenesis in vitro: Differential Induction by Modified Matrix- a Biochemical and Morphological Study*: (induction/chondrogenesis/proteoglycans/SEM analysis).

The stimulation of somite chondrogenesis by extracellular matrix components was studied by monitering the synthesis of cartilage-specific large proteoglycan aggregates. Chick embryonic sternal proteoglycans were separated into various components: monomers, hyaluronic acid, link protein and glycosaminoglycan side chains. The effects of these components, either individually or in various combinations, on somite chondrogenesis was examined.