Quinazolinone derivatives as orally available ghrelin receptor antagonists for the treatment of diabetes and obesity.

The peptide hormone ghrelin is the endogenous ligand for the type 1a growth hormone secretagogue receptor (GHS-R1a) and the only currently known circulating appetite stimulant. GHS-R1a antagonism has therefore been proposed as a potential approach for obesity treatment. More recently, ghrelin has been recognized to also play a role in controlling glucose-induced insulin secretion, which suggests another possible benefit for a GHS-R1a antagonist, namely, the role as an insulin secretagogue with potential value for diabetes treatment.

A High-throughput two-phase partition assay to measure the activity of lipid-metabolizing enzymes.

A new method to measure the activity of lipid-metabolizing enzymes is described. Subsequent to an enzymatic reaction, a two-phase system (organic/aqueous) is established by the addition of a phase partition scintillation fluid (PPSF). The PPSF serves as a scintillation fluid, a phase partition agent, and a carrier/separator of an organic-soluble radiolabeled reaction substrate or product.

HTS in the new millennium: the role of pharmacology and flexibility.

Over the past decade, high throughput screening (HTS) has become the focal point for discovery programs within the pharmaceutical industry. The role of this discipline has been and remains the rapid and efficient identification of lead chemical matter within chemical libraries for therapeutics development. Recent advances in molecular and computational biology, i.

Specific antigen binding by proteins secreted by an antigen-specific T cell hybrid.

Antigen-specific molecules secreted by a murine T cell hybrid specific for azobenzene arsonate (ABA) were purified from ascites fluid by ion exchange chromatography and affinity for antigen. The antigen-specific proteins were purified 250 fold and were resolved predominantly as Mr 110,000 polypeptides by reduction and SDS-polyacrylamide gel electrophoresis. The ability of these molecules to bind antigen was analyzed by an ELISA using antigen-coated microtiter trays.

T cell non-MHC-restricted antigen-binding molecules secreted or associated with the cell membrane are antigenically distinct.

Some T cells produce membrane-associated or soluble molecules which bind nominal antigen specifically (TABM) and effect immunoregulation or events similar to cell-mediated hypersensitivity. We have used polyclonal antisera raised against an azobenzene arsonate (ABA)-specific TABM secreted by an ABA-specific T cell hybrid or against TNP-specific polypeptides produced by immunoregulatory T cells to identify the expression of soluble (secreted) or membrane-associated TABM. Ascites fluid or culture medium containing a T cell hybrid or T cell lines, respectively, contain TABM recognized only by an antiserum specific for the secreted T cell hybrid (ABA-specific) derived TABM.

Pentoxifylline-induced modulation of human leukocyte function in vitro.

We previously demonstrated that pentoxifylline stimulated leukocyte migration in vitro and leukocyte accumulation in vivo and protects neonatal mice from experimentally induced Staphylococcus aureus infections. In the present studies we have investigated pentoxifylline's effect on human leukocyte function in vitro. In these studies we demonstrate that pentoxifylline at low concentrations (ie, 0.

Pentoxifylline enhancement of defective neutrophil function and host defense in neonatal mice.

Decreased neutrophil (PMN) chemotaxis is thought to contribute to the increased morbidity and mortality from infection in newborn infants. Pentoxifylline, a methylxanthine, has previously been shown to augment PMN chemotaxis in vitro. The authors therefore investigated the effects of pentoxifylline on 1) in vitro PMN chemotaxis, 2) in vivo leukocyte accumulation, and 3) protection against Staphylococcus aureus infection in newborn mice.

Polymorphonuclear leukocyte heterogeneity in neonates and adults.

We have used a mouse monoclonal antibody (31D8) to determine whether differences in neutrophil (PMN) subpopulations might help explain decreased PMN chemotaxis in neonates compared with that of adults. 31D8 has been shown to bind heterogeneously to adult PMNs. Approximately 80% of the PMNs that strongly bind 31D8 (31D8 "bright") are the same cells that depolarize and migrate chemotactically when stimulated with the chemoattractant N-formyl-methionylleucylphenylalanine, while the 20% that weakly bind 31D8 fail to similarly respond.

Proliferative and cytotoxic immune functions in ageing mice. I. Sequence of decline of reactivities measured under optimal and suboptimal sensitization conditions.

Individual young adult, middle-aged, and old C57BL/6J male mice were tested for in vitro generated proliferative and cytotoxic responses to H-2 alloantigens under a variety of sensitization conditions. Proliferation in mixed lymphocyte culture (MLC) had decreased by 14 months of age (middle-aged), whether measured by directly assaying cultures in microtitre plates (micro MLC) or by labelling aliquots taken from large culture tubes (macro MLC). Cytotoxicity did not decline until a later age if sensitization was done in large tubes (macro cell-mediated lympholysis, CML).

Aging increases expression of LPS-induced autoantibody-secreting B cells.

Escherichia coli lipopolysaccharide (LPS), a polyclonal B cell activator, has been employed to achieve in vitro stimulation of autoantibody-secreting B cells in young adult and aged mice of long-lived strains as assayed in a hemolytic plaque technique to syngeneic mouse erythrocytes. Aged 21- to 24-month-old C57BL/6J and (C57BL/10Sn x C3H/HeDiSn)F1 mice were found to express 3 to 4 times as many LPS-induced plaque-forming cells (PFC) to autologous erythrocytes than did younger 6-month-old animals. With the use of cyclophosphamide (CY), a significant enhancement of auto-PFC production in young mice occurred, approaching levels found in non-CY-treated old mice.

Influence of controlled dietary restriction on immunologic function and aging.

The underfeeding regimens tested in rodents for life span prolongation and/or immunologic effects result in a complex blend of protein and energy restriction while offering at least adequate amounts of all other essential nutrients. Underfeeding started at weaning and continued throughout life represents the only proved way of slowing the rate of aging in homeotherms. Mounting evidence indicates that underfeeding initiated later in life may also influence life span favorably.