Effects of gonadal steroids on agonistic behavior of female Peromyscus leucopus

The role of gonadal hormones in modifying agonistic behavior of female P. leucopus was examined by means of ovariectomy and treatment with estradiol benzoate (EB), progesterone (P), or testosterone propionate (TP). Aggression was lower in diestrous females than in proestrous females, and was eliminated by ovariectomy. Submissive behavior increased following ovariectomy; surgery had no effect on investigative behavior. Administration of EB had no effect on aggressive or submissive behavior, but higher dosages caused an increase in investigative and sexual behavior. Higher dosages of P increased aggression; P had no effect on submissive or investigative behavior. An increase in aggression also resulted from administration of high levels of TP. TP also caused an increase in investigative behavior, and had no effect on submissive behavior. These results may be due to direct effects of the administered hormones on behavior or to indirect effects such as a stimulation of prolactin secretion or alteration of adrenal function.     

Fluidized bed adsorption for whole broth extraction.

Fluidized bed adsorption using a high-density synthetic resin has proven to be an invaluable technique for separating novel compounds from unfiltered fermentation broths during the very early stages of fermentation development, where product concentrations are typically in the parts per million range. Previous initial downstream processing strategies consisted of cell separation from whole broth or direct extraction with water-immiscible solvents, both of which resulted in lengthy time cycles, conflicts with existing operations requiring the use of high-cost centrifugal separators, and environmental/solvent recovery concerns. Laboratory and subsequent pilot plant process development work along with concomitant improvements in yield, quality, and time cycles are presented for one of several fluidized bed processes piloted in Merck's Natural Product Isolation facility.     

The effects of antifungal substances on some zoosporic fungi (Kingdom Fungi)

Zoosporic fungi constitute a large group of true fungi which inhabit freshwater, brackish, marine and soil ecosystems. In general, very little is known about the effects of antifungal substances on the growth and survival of most species. This review focuses on experimental research with those isolates which have been studied, especially in some species of Synchytrium, Olpidium, Batrachochytrium, Allomyces, Blastocladiella, Neocallimastix. These genera represent genetically diverse groups. Although the research discussed here is restricted to a small sample, some general conclusions can be reached about zoosporic fungi as a whole. Like many other eukaryotic microorganisms, zoosporic fungi are sensitive to a large number of antibiotics, fungicides, surfactants, bacterial metabolites, metabolic poisons, proteins, heavy metals and other antifungal substances. These include substances commonly released into the environment for the control of plant and animal diseases, for increasing production of domestic animals and in the form of waste products from industry. It is possible that the release of antifungal substances into the environment might cause significant changes in the community structure of zoosporic fungi as well as of other groups of microorganisms which play significant roles in food web dynamics and ecosystem complexity. However, this needs documentation by quantitative studies. For these reasons, extensive research on the effects of antifungal substances is much needed.     

Mitigation of reactive metabolite formation for a series of 3-amino-2-pyridone inhibitors of Bruton’s tyrosine kinase (BTK)

Reactive metabolites have been putatively linked to many adverse drug reactions including idiosyncratic toxicities for a number of drugs with black box warnings or withdrawn from the market. Therefore, it is desirable to minimize the risk of reactive metabolite formation for lead molecules in optimization, in particular for non-life threatening chronic disease, to maximize benefit to risk ratio. This article describes our effort in addressing reactive metabolite issues for a series of 3-amino-2-pyridone inhibitors of BTK, e.g. compound 1 has a value of 459 pmol/mg protein in the microsomal covalent binding assay. Parallel approaches were taken to successfully resolve the issues: establishment of a predictive screening assay with correlation association of covalent binding assay, identification of the origin of reactive metabolite formation using MS/MS analysis of HLM as well as isolation and characterization of GSH adducts. This ultimately led to the discovery of compound 7 (RN941) with significantly reduced covalent binding of 26 pmol/mg protein.     

Immunohistochemical detection of the beta4 integrin subunit in pancreatic adenocarcinoma.

The expression of the beta4 integrin subunit protein in pancreatic cancer was investigated using routine immunohistochemical methods on paraffin-embedded archival material. Forty-eight cases of pancreatic ductal adenocarcinoma were immunostained with a monoclonal antibody to the beta4 integrin subunit, and the extent of staining was compared with that seen in non-cancerous pancreatic tissues, including 15 separate cases of chronic pancreatitis and 6 sections from normal pancreas. We found that the beta4 integrin subunit protein was overexpressed in the majority of pancreatic carcinoma cases tested, whereas chronic pancreatitis and normal pancreas did not display substantial levels of expression.     

Protection of sensors for biological applications by photoinitiated chemical vapor deposition of hydrogel thin films

We report photoinitiated chemical vapor deposition (piCVD), a gentle synthetic method for the preparation of ultrathin films (approximately 100 nm) of the hydrogel poly(hydroxyethyl methacrylate) (pHEMA). piCVD occurs near room temperature and requires only mild vacuum conditions. The deposited films swell rapidly and reversibly in buffer solution, and the swelling properties can be controlled via the deposition conditions. Analysis of the swelling data indicates that the mesh size of the hydrogel creates a selectively permeable coating. The mesh is large enough to allow small molecule analytes to permeate the film but small enough to prevent the transport of large biomolecules such as proteins. X-ray photoelectron spectroscopy (XPS) shows that the films decrease nonspecific adhesion of the protein albumin by nearly 8-fold over bare silicon. A dry process, piCVD is suitable for coating particles with diameters as small as 5 microm. The absence of solvents and plasmas in piCVD allows films to be directly synthesized on optode sensors without degradation of sensitivity or response time.