Membrane-bound LERK2 ligand can signal through three different Eph-related receptor tyrosine kinases.

The Eph-related family of receptor tyrosine kinases consists of at least 13 members, several of which display distinctive expression patterns in the developing and adult nervous system. Recently, a small family of ligands, structurally related to the B61 protein, was identified. Binding of these ligands to Eph-related receptors did not, however, elicit measurable biological signals in cultured cells. In order to study functional interactions between B61-related ligands and Eph-related receptors, we constructed chimeric receptors, containing an Eph-related ectodomain and the cytoplasmic domain of the TrkB neurotrophin receptor. Expression and activation of such chimeric receptors in NIH 3T3 cells induced transformation in focus formation assays. Membrane-bound LERK2 ligand is shown to signal through three different Eph-related receptors, namely Cek5, Cek10 and Elk. LERK2, however, fails to interact functionally with the Cek9 receptor. Quantitative analysis including binding assays indicates that Cek10 is the preferred LERK2 receptor. Preliminary mutagenesis of the LERK2 protein suggests a negative regulatory role for its cytoplasmic domain in LERK2 signaling.     

Reactivity of sulphydryl groups of cytosolic and mitochondrial bovine aspartate aminotransferases

Summary Reactivity of sulphydryl groups of cytosolic and mitochondrial aspartate aminotransferases from ox heart has been studied. A total of 5 and 7 cysteine residues per monomer are present in cAATo and mAATo, respectively. In native conditions only a single sulphydryl group can be titrated by Nbs₂ while the catalytic activity remains unchanged, however in the mitochondrial isozyme the reactivity depends on the functional state of the enzyme. Reactivity toward NEM reveals the existence of a syncatalytic sulphydryl group in the cytosolic isozyme. Titration of cAATo with pMB at pH 8 and pH 5 confirms the existence of two exposed sulphydryl groups with a different reactivity. The results compared with those reported on the corresponding isozymes from pig and chicken heart show that syncatalytic sulphydryl groups are of general occurrence in these enzymes.     

The Yale Affiliated Hospital Program in Internal Medicine

In July, 1975, the Departments of Internal Medicine at the Yale University School of Medicine and eight community hospitals in southern and western Connecticut formed the Yale Affiliated Hospital Program (YAHP) in Internal Medicine. The YAHP provides a planned and focused program of continuing education for medical staff and housestaff at the affiliated hospitals. Six formats for the over 1,000 rounds, lectures, and conferences given annually are used. The members of the YAHP also cooperate in housestaff and faculty recruiting, evaluation of quality of care and evaluation of the process of continuing medical education itself. This report summarizes the organization, goals and future plans of the YAHP.     

Complex expression of the genes coding for plasminogen activators and their inhibitors in HeLa-smooth muscle cell hybrids.

As cells progress through the multistep process of neoplastic transformation, they eventually acquire the property of invasive behavior. Although both plasminogen activators (PA) and their inhibitors (PAI) contribute to this process, their regulation in normal and transformed cells remains poorly defined. Because somatic cell hybrids provide useful tools for examining the transformation pathway, tumorigenic and invasive HeLa cells were fused with human normal vascular smooth muscle cells and tested for invasion-related parameters, including the expression of PA and PAI genes, and matrix degradation. Both parental cell lines produced large amounts of PAI activities with no detectable PA in either cellular or secreted form. Opposite findings were obtained with the hybrid cell lines, which demonstrated the presence of receptor-bound and secreted PA but absence of enzymatically measurable PAI activities. Both urokinase-type and tissue-type PA were found in cell-associated and secreted form in the hybrid cells. In addition, expression of the urokinase-type PA receptor gene was found in the three hybrid cells and the vascular smooth muscle cells but not in the HeLa cells. Expression of active, receptor-bound and secreted PA provided the nontumorigenic hybrid cells with the enzymatic tools to degrade extracellular proteins in a plasminogen-dependent manner. Thus, the hybrid cells lost tumorigenicity while retaining the tissue-degrading capability of HeLa cells. These hybrid cell lines should prove to be important reagents for investigating the complex regulatory control of PA and PAI gene expression.     

Combined control of Lasioderma serricorne (F.) and Ephestia elutella (Hbn.) in a tobacco processing facility by attracticide method

Results on application of attracticide method in the combined control of cigarette beetle, Lasioderma serricorne and tobacco moth, Ephestia elutella, infesting a tobacco processing facility are reported. Experimental devices with cross-panel stripes treated with microencapsulated permethrin at 6% (a.i.) and baited at same time with (4,6-dimethyl-7-hydroxynonan-3-one) serricornin and (Z,E)-9,12-tetradecadien-1 ol acetate (TDA) were used for 2 years (2017 and 2018) in an Italian tobacco processing facility. The experiment demonstrated that the presence of both serricornin and TDA dispensers on cross-panel striped devices had no affect on the numbers of L. serricorne and E. elutella male adults caught. After 2 years, the densities of adult males were clearly suppressed in room treated with attracticide compared to control room. Thus, the 2017–2018 experiment suggests that attracticide devices with two pheromone lures and microencapsulated permethrin at 6% (a.i.) can be effective suppression tools for managing combined pest populations of L. serricorne and E. elutella in tobacco facilities. The reduction of male infestation by L. serricorne ranged from 36% to 87%, and in E. elutella, the reduction of infestation ranged from 63% to 91%.     

A potential role of alkaloid extracts from Salsola species (Chenopodiaceae) in the treatment of Alzheimer's disease

From the aerial parts of Salsola oppositofolia, S. soda and S. tragus an alkaloid extract was obtained and tested to evaluate antioxidant and anti-cholinesterase activities. The in vitro study of the antioxidant activity by the DPPH method revealed a significant activity of Salsola alkaloid extracts with IC₅₀ values ranging from 16.30 μg/mL for S. oppositifolia to 26.17 μg/mL for S. tragus. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. S. tragus alkaloid extract exerted the highest inhibitory activity against AChE (IC₅₀ of 30.2 μg/mL) and BChE (IC₅₀ of 26.5 μg/mL). Interestingly, S. soda and S. oppositifolia exhibited a selective inhibitory activity against BChE with IC₅₀ values of 34.3 μg/mL and 32.7 μg/mL, respectively. Tetrahydroisoquinoline alkaloids were identified and quantified by GC/MS analysis.