Electrophoretic protein and enzyme patterns and antigenic structure in Verticillium dahliae and V. albo-atrum

The acrylamide gel electrophoretic patterns of esterases and phosphatases are not helpful in the identification ofVerticillium dahliae andV. albo-atrum. Protein profiles of wild-type isolates of the two species show bands characteristic to each species. For the genus, nine characteristic bands were detected; these remained in natural variants, but in ultraviolet variants only six of them persisted. Of the three bands characteristic ofV. dahliae, only one persisted in natural and in ultraviolet variants.V. albo-atrum showed two characteristic bands. Immunoelectrophoretic analysis reveals the existence of greater intra-specific affinities than at the inter-specific level. Variants from one isolate have immunoelectrophoretic constituents similar to those of the parent and can be identified employing these criteria. Both acrylamide gel electrophoresis and immunoserology, however, affirm the close genetic relationship of the two form-species.     

Role of the Phagocyte in Host-Parasite Interactions VIII. Effect of Whole-Body X Irradiation on Nicotinamides, Lysosomal Enzymes, and Bactericidal Activities of Leukocytes During Phagocytosis

By studying the effects of whole-body X irradiation on phagocytosis, a correlation between the metabolic and bactericidal activities of leukocytes following X irradiation was demonstrated. The total nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) content of polymorphonuclear neutrolphils (PMN) isolated from irradiated guinea pigs increased significantly when compared to nonirradiated controls. The ratio of unreduced to reduced (NAD) generally increased in PMN isolated from irradiated animals. This occurred with both resting and phagocytizing cells. The ratio of unreduced to reduced NADP of resting PMN isolated from irradiated animals had a tendency to increase. However, in phagocytizing cells a significant decrease in the ratio was noted. The total acid and alkaline phosphatase and beta-glucuronidase increased up to about 10 days postirradiation. These lysosomal enzymes returned to approximately normal by the 17th day postirradiation. All three lysosomal enzymes (acid and alkaline phosphatases and beta-glucuronidase) were released from the granules at a significantly faster rate during phagocytosis after irradiation. The bactericidal activities of PMN isolated from irradiated animals gradually decreased, and in some cases increased growth of the organisms was observed. The uptake or association of bacteria with PMN isolated from irradiated animals varied with the postirradiation time. Generally, a correlation with bactericidal activities could be made. The data indicate that the bactericidal system in phagocytes consists of at least two agents, H(2)O(2) and myeloperoxidase.     

A dnaB analog function specified by bacteriophage P7 and its comparison to the similar function specified by bacteriophage P1

Summary Evidence is presented that bacteriophage P7 specifies an analog of the E. coli DNA replication protein, dnaB. As in the related bacteriophage P1 (D'Ari et al., 1975; Ogawa, 1975), in lysogens of P7, the production of the analog protein is repressed and constitutive mutants could be isolated. Such constitutive of several dnaB(ts) mutations and also rescue a strain carrying a dnaB amber mutation. While neither P7 nor the mutant P1bacban (defective in the structural gene ban) could suppress dnaB(ts) mutations efficiently, recombinants between these two phages could do so, indicating the presence of a functional dnaB analog gene (called sdb) on P7. In a dnaB amber strain suppressed by the presence of the constitutive mutant P7csb, bacteriophage failed to replicate which is a further similarity between P7 and P1. P7csb mutants or P7-P1bacban recombinants were found to be less thermoresistant than P1bac1 suggesting that the P7-specified dnaB analog protein or its production is relatively less tolerant of temperatures above 37°C.     

Effect of short-term treatment of eugenol on the seminal vesicles of adult albino rats

The structure and biochemical content of adult albino rat seminal vesicles, were studied, after administration of two different doses of eugenol for 10 days (0.2 and 0.3 mg/kg/day, i.m.). Marked decreases in the concentrations of nucleic acids, fructose and total protein as well as RNA/DNA ratio (61%) and protein/DNA ratio (27%) were observed. A remarkable increase in phospholipid concentration was noted with a corresponding decrease in neutral lipids. Histologically, eugenol treated animals showed degeneration of the secretory columnar cells and well developed myofibrillar connective tissues when compared to control animals.     

Molecular characterization of a gene encoding N-myristoyl transferase (NMT) from Triticum aestivum (bread wheat).

Myristoyl-CoA:protein N-myristoyl transferase (NMT; EC 2.3.1.97) acylates the Gly residue abutting the N-terminal Met with a myristic acid following the removal of the Met residue in certain eukaryotic proteins, and in some cases myristoylation is essential to cell growth and survival. We report the cloning of a full-length cDNA encoding NMT from Triticum aestivum (TaNMT). The cDNA included a predicted open reading frame of 1317 nucleotides, which encoded a predicted protein of 438 amino acids containing all of the residues that are important for NMT activity. The TaNMT amino acid and nucleotide sequences were compared with NMTs from 14 other species encompassing a wide array of taxonomic groups. Among the experimentally validated NMTs, TaNMT was most similar to that of Arabidopsis thaliana. Southern blot analysis of wheat genomic DNA showed that TaNMT is encoded by a single copy gene, with one copy per haploid genome. We expressed TaNMT in Escherichia coli cells and determined that the recombinant protein possessed NMT activity, catalyzing the N-myristoylation of peptides from known or putatively myristoylated proteins from plants and animals without a strong preference for the plant peptides. TaNMT is the second experimentally validated plant NMT sequence and the first from a monocotyledonous species.     

Scaffold-based spheroid models of glioblastoma multiforme and its use in drug screening

Among several types of brain cancers, glioblastoma multiforme (GBM) is a terminal and aggressive disease with a median survival of 15 months despite the most intensive surgery and chemotherapy. Preclinical models that accurately reproduce the tumor microenvironment are vital for developing new therapeutic alternatives. Understanding the complicated interactions between cells and their surroundings is essential to comprehend the tumor's microenvironment, however the monolayer cell culture approach falls short. Numerous approaches are used to develop GBM cells into tumor spheroids, while scaffold-based spheroids provides the opportunity to investigate the synergies between cells as well as cells and the matrix. This review summarizes the development of various scaffold-based GBM spheroid models and the prospective for their use as drug testing systems.     

High frequency plant regeneration via somatic embryogenesis in cell suspension cultures of cowpea, Vigna unguiculata (L.) Walp.

Summary Embryogenic callus was induced from primary leaves of Vigna unguiculata (L.) Walp. in MS medium (Murashige and Skoog, 1962) containing 2,4-dichlorophenoxyacetic acid (2,4-D). Greenish-white, friable embryogenic calluses were used to establish suspension cultures. A shaking speed of 90 rpm and 0.4 ml packed cell volume per 25 ml medium were found to be optimal for maintaining suspension cultures. Globular, heart-shaped and torpedo-shaped embryos were developed in suspension culture containing 4.52 μM 2,4-D. Maturation of cotyledonary-stage somatic embryos was achieved on 0.05 μM 2,4-D, 5 μM abscisic acid and 3% mannitol. Twenty-two percent of the embryos were converted into plants and survived; survival in the field was 8–10%.