Characterization of midgut proteinase activities of white grubs: Lepidiota noxia,Lepidiota negatoria,and Antitrogus consanguineus (scarabaeidae,melolonthini)

The proteinases in the midguts of three scarab white grub species, Lepidiota noxia, L. negatoria, and Antitrogus consanguineus, were investigated to classify the proteinases present and to determine the most effective proteinase inhibitor for potential use as an insect control agent. pH activity profiles indicated the presence of serine proteinases and the absence of cysteine proteinases. This was confirmed by the lack of inhibition by specific cysteine proteinase inhibitors. Trypsin, chymotrypsin, elastase, and leucine aminopeptidase activities were detected by using specific synthetic substrates. A screen of 32 proteinase inhibitors produced 9 inhibitors of trypsin, chymotrypsin, and elastase which reduced proteolytic activity by greater than 75%. © 1995 Wiley-Liss, Inc.     

An in situ assay for induced diphtheria-toxin-resistant mutants of diploid human fibroblasts

The sensitivity of diploid human fibroblasts to the cytotoxic effects of diphtheria toxin (DT) depended on the cell growth status. Exponentially growing cells treated with 10^?3-1 lethal flocculating units (LF) of DT/ml for 4 days survived with a frequency of 4 × 10^?4. However, the DT-resistant phenotype of colonies isolated under these conditions was not stable. When the growth of the cells had been arrested by confluence or deprivation of serum growth factors prior to treatment with DT (4 days, 10^?3-0.6 LF/ml), the survival decreased to 2 × 10^?6 and the resistance of isolated colonies was stable. An in situ assay for induced DT-resistant mutants was developed in order to avoid problems associated with the possible reduced viability of the mutants relative to that of wild-type cells. A reproducible and linear dose response was obtained for the induction of DT-resistant mutants by ethylnitrosourea. The mutants were induced with high frequency by this compound (e.g., 10^?3 mutants/viable cell at a 37% survival dose); complete expression of the mutant phenotype occurred after 6 generations of growth under nonselective conditions. Isolated mutant colonies showed stable resistance to DT and were cross-resistant to Pseudomonas aeruginosa exotoxin A.     

Comparative Study of Wastewater Lagoon with and without Water Hyacinth

A 3-year study was conducted on an existing, one-cell, facultative sewage lagoon having a total surface area of 3.6 ha and receiving a BOD₅ loading rate of 44 kglhald (40 Iblald). The comparative experimental periods ran from July through November for 3 consecutive years. During the first period, water hyacinths completely covered the lagoon. The water hyacinth coverage was reduced to 33% of the total surface area the second year. The lagoon, free of all vascular aquatic plants the third year, was monitored for comparative purposes. The most significant improvement overall in the effluent quality occurred when water hyacinths covered the entire lagoon. During this period the effluent BOD₅ and TSS were 23 and 6 mgll, respectively. Without water hyacinths, the effluent BOD₅ and TSS were 52 and 77 mgll, respectively. The effluent total organic carbon concentration with water hyacinths averaged 40 mgll, and without water hyacinths, 72 mgll. A discussion of the results from this 3-year study is presented in this paper along with associated problems that were observed when water hyacinths were introduced into the lagoon and altered its behavior from that of a normal facultative lagoon.     

The Chicago variant of clinical galactosemia

Summary A new variant of clinical galactosemia with two hitherto unidentified alleles on the transferase locus in one family is described. This new clinical variant of transferase has 25% of normal control activity in blood and in skin fibroblasts, and the patient accumulates galactose-1-phosphate in blood on an unrestricted galactose diet. Using starch gel electrophoresis on the hemolysate of the family members, a fast-moving transferase with mobility in between those of the normal control and of the Duarte variant is identified. This new allele is designated as (fast-moving Chicago variant). In addition, a second new allele was documented in this family by studying the instability of the transferase enzyme in hemolysates of family members at 50°C for various time intervals. This new allele is designated as (heat-labile Chicago variant). On the basis of the studies, the transferase genotype of this patients is thought to be a double heterozygote compound, /GALT^G.     

Mitogenic property of the apical ectodermal ridge

While the apical ectodermal ridge (AER) is well known for its required role in the development of distal parts of the limb and for its ability to stimulate limb duplications, the mechanism of its action is unknown. In this study we use a culture system previously developed by M. Globus and S. Vethamany-Globus (1976, Differentiation6, 91–96) in which an AER grafted onto a high-density cell culture of limb mesenchyme stimulates the formation of an outgrowth. Time-lapse movies taken during the outgrowth period demonstrated no cellular activities other than cell division. Both the mitotic index and labeling index in the mesenchyme were significantly elevated under the AER as compared to that without AER, indicating that the AER provides a growth-promoting stimulus which increases the proportion of dividing cells. On the other hand, nonridge ectoderm had no detectable effect on the mitotic index. Treatment of cultures with cytosine arabinoside both inhibited DNA synthesis and prevented AER-induced outgrowth. These results demonstrate a mitogenic capacity of AER tissue and suggest that mesenchymal outgrowth requires this activity. The mitogenic property of the AER is considered in relation to limb outgrowth in situ.     

The Friesner Herbarium (BUT) of Butler University

The Friesner Herbarium (BUT) of Butler University is a collection of over 100,000 specimens built from the personal herbarium of Ray C. Friesner. He and other botanists at Butler amassed one of the largest and most complete collections of Indiana plants. Active exchange from the 1920’s through the 1940’s increased the holdings of plants from other states. Although the collection does not contain many type specimens, it is rich in vouchers from floristic and ecological studies conducted in the first half of the 20th century and published in the scientific journal,Butler University Botanical Studies.     

Endopeptidase-24.11, a Cell-Surface Peptidace of Central Nervous System Neurons, Is Expressed by Schwann Cells in the Pig Peripheral Nervous System

Endopeptidase-24.11 is a 90-kDa surface glycoprotein with the ability to hydrolyze a variety of biologically active peptides. Interest in this enzyme is based on the consensus that it may play a role in the termination of peptide signals in the central nervous system. In the present study, we have investigated the distribution of endopeptidase-24.11 in two nerves of the peripheral nervous system of newborn pigs: the sciatic, composed of a mixture of myelinated and nonmyelinated axons, and cervical sympathetic trunk in which greater than 99% of the axons are nonmyelinated. The endopeptidase was monitored enzymatically, as well as by immunoblotting and immunocytochemistry using mono- and polyclonal anti-endopeptidase antibodies. Endopeptidase-24.11 was detected in both the sciatic nerve and the cervical sympathetic trunk. Membrane preparations from sciatic nerve hydrolyzed 125I-insulin B-chain, and more than 50% of the activity was inhibited by phosphoramidon with an IC50 concentration of 3.2 nM. Moreover, a 90-kDa polypeptide was detected by immunoblotting of sciatic nerve membranes. The type of cells expressing the endopeptidase was determined by immunohistochemistry. In teased nerve preparations, these cells were identified morphologically as myelin- and non-myelin-forming Schwann cells. Endopeptidase-24.11 was also expressed by cultured Schwann cells from sciatic nerve and cervical sympathetic trunk maintained for 3 h in vitro. The presence of endopeptidase-24.11 on the Schwann cell surface raises the possibility of a potential role for the enzyme in nerve development and/or regeneration.     

Epithelial differentiation in the absence of extracellular matrix

Summary To investigate the regulation of epithelial differentiation, normal human epidermal keratinocytes were cultured floating on the surface of culture medium without attachment to a solid substrate. Keratinocytes spread out on the surface of the medium, proliferated and differentiated either into several flat lacy sheets 1 to 3 cells thick (on medium containing 0.15 mM calcium) or formed one single aggregate of cells from 5 to 15 cells in thickness on medium containing 1.15 mM calcium. The cell aggregates demonstrated a pattern of ordered epithelial differentiation. Levels of progressive differentiation resembling the structure of normal human epidermis were identified by light microscopy, immunohistochemistry, and electron microscopy. Differentiation proceeded from cells at the air side toward cells at the medium side with basal appearing cells on the air side and keratinocytes expressing filaggrin and involucrin on the side toward the medium. These results demonstrate that organized epithelial differentiation can occur in the absence of extracellular matrix. In contrast with other air-liquid interface cultures, epithelial differentiation in the absence of extracellular matrix progresses from air towards medium.     

Analysis of neonatally induced tolerance of H-2 alloantigens

There is a considerable amount of evidence, confirmed and extended by our studies, in favor of clonal deletion of alloantigen-reactive cells in neonatally induced transplantation tolerance. We have demonstrated in adult mice bearing long-standing skin allografts that lymphocytes specifically reactive with the tolerated H-2 alloantigens are undetectable by mixed lymphocyte and graftversus-host reactions, and in cell-mediated lympholysis. In addition, lymphoid cells capable of suppressing the reactivity of syngeneic normal lymphocytes in these assays similarly escape detection. Moreover, putative precursors of T cells specific for the tolerated antigens cannot be activated polyclonally with concanavalin A (Con A), nor can they be identified among thymocytes ofH-2-tolerant mice. Since the tolerant state can be adoptively transferred with lymphohematopoietic cells to adult, syngeneic mice, we infer that transplantation tolerance is maintained by an active process that achieves specific clonal deletion at an early stage in the ontogeny of alloreactive T lymphocytes.