Banning Fisheries Discards Abruptly Has a Negative Impact on the Population Dynamics of Charismatic Marine Megafauna

Food subsidies have the potential to modify ecosystems and affect the provision of goods and services. Predictable Anthropogenic Food Subsidies (PAFS) modify ecosystems by altering ecological processes and food webs. The global concern over the effects of PAFS in ecosystems has led to development of environmental policies aimed at curbing the production or ultimately banning of PAFS. However, the effects of reducing or banning PAFS are not known. We explore the consequences of PAFS removal in a marine ecosystem under two scenarios: 1) gradual reduction, or 2) an abrupt ban, using a mass balance model to test these hypotheses–The reduction or loss of PAFS will: i) modify trophic levels and food webs through effects on foraging by opportunistic species, ii) increase the resilience of opportunistic species to food shortages, and iii) modify predator–prey interactions through shifts in prey consumption. We found that PAFS lower the trophic levels of opportunistic scavengers and increase their food pathways. Scavengers are able to switch prey when PAFS are reduced gradually but they decline when PAFS are abruptly banned. PAFS reduction to a certain minimal level causes a drop in the ecosystem’s stability. We recommend gradual reduction of PAFS to a minimal level that would maintain the ecosystem’s stability and allow species exploiting PAFS to habituate to the food subsidy reduction.     

Melanoma progression exhibits a significant impact on connexin expression patterns in the epidermal tumor microenvironment

Melanoma depends on, interacts with and reacts to the stroma in which it is embedded, including fibroblasts, extracellular matrix, endothelial cells and immune cells. However, the impact of melanoma on the epidermal tumor microenvironment—the multilayered epithelium of the skin—is poorly understood. Gap junctions are essential for intercellular communication and involved in proliferation, differentiation and homeostasis of keratinocytes. We have shown previously that the gap junction proteins connexin 26 and 30 (Cx26 and Cx30) are induced in the epidermal tumor microenvironment of skin cancers including melanoma. This study compares the extent of Cx26, Cx30 and Cx43 expression in the epidermal microenvironment of melanocytic nevi and melanomas and its association with melanoma thickness, proliferative index of the tumor and its microenvironment, and with 5-year metastasis and survival. We found that induction of Cx26 and Cx30 cell–cell border expression in the epidermal tumor microenvironment correlates to malignancy. Importantly, there was a significant correlation of tumor thickness with the vertical epidermal Cx26 and Cx30 expression pattern and the horizontal Cx26 dissemination. Furthermore, horizontal Cx26 expression correlated with metastasis. Vertical epidermal expression patterns of Cx26 and Cx30 significantly correlated with the proliferative index in the epidermal tumor microenvironment but not with the proliferative index in the tumor. In contrast, Cx43 did not correlate with malignancy, thickness or proliferative index. In summary, here we show for the first time a significant association between the progression of melanoma and alterations in its epithelial tumor microenvironment.     

Humoral factors released during trauma ofAplysia body wall

1. Preliminary, general chemical characteristics of substances in artificial sea water (ASW) washed through stimulated body wall (SBW) and in hemolymph taken from noxiously stimulated animals (SHL) were consistent with those of classical neurotransmitters, amino acids, and small- to medium-sized peptides. 2. 5-Hydroxytryptamine (5HT) and acetylcholine (ACh), unlike SBW and SHL, caused relaxation when perfused into isolated body wall. FMRFamide produced a biphasic response--brief contraction followed by prolonged relaxation. 3. Small cardioactive peptide (SCPB) caused body wall contractions similar to those produced by SBW and SHL, except that SCPB contractions displayed more desensitization and were completely blocked by 30 mM CoCl2. SCPB and SBW contractions were synergistic. 4. Dopamine caused persistent body wall contractions similar to those of SBW and SHL. Dopamine contractions were reduced but not blocked by 30 mM CoCl2. Unlike SBW activity, dopamine activity was reduced by alkalinization. 5. Glutamate and taurine produced strong but usually short-lasting body wall contractions. Adenosine, octopamine, arginine vasotocin, and cholecystokinin (CCK-8) caused weak or variable contractions. Met-enkephalin and somatostatin caused no obvious body wall responses. 6. When superfused over the fully sheathed abdominal ganglion, FMRFamide, met-enkephalin, glutamate, aspartate, and taurine reduced the magnitude of the gill-withdrawal reflex elicited by siphon nerve stimulation. 7. Taken together with earlier results, these data suggest a preliminary framework for trauma signal pathways. It is proposed that stress hormones (perhaps including FMRFamide, SCPs, 5HT, and dopamine) are released into hemolymph from neuroendocrine cells. Effective amounts of active intracellular solutes such as amino acids may also be released by extensive cellular rupture. Various humoral signals produce slow effects that contribute to hemostasis, balling up, increased cardiac output, and reflex suppression.     

A new species of land planarian preying on termites in Kenya (Platyhelminthes: Turbellaria: Tricladida: Terricola)

A new species of land planarian is described from Kenya. Microplana rermirophaga sp. nov. preys on termites by capturing them at the openings to their nest. The pharynx is unusually far forwards for a land planarian and this is probably related to the active nature of the prey. There is an anterior depression caused by the termination of parenchymal longitudinal muscle bundles which might act as a sucker. All specimens are immature which leads to some difficulty in assigning the species to a genus.     

Human mitochondrial DNA types in Finland

Summary Variation in mitochondrial DNA (mtDNA) in a sample of 110 Finns was analyzed with six restriction enzymes, AvaII, BamHI, HaeII, HinII, HpaI, and MspI, by using total blood cell DNA probed with mouse mtDNA. Two new enzyme morphs were observed, one for HaeII and one for HindII. Double-digestion experiments indicated that the BamHI morphs 2 and 3 result from base changes leading to AvaII morphs 3 and 9, respectively. Of the ten different mtDNA types observed, defined by restriction fragment patterns, seven have been previously described in Caucasoid populations. The three new Finnish mtDNA types can be derived from Caucasoid lineages by single restriction site changes. The results were used to reconstruct a phylogenetic tree for Caucasoid mtDNA types defined by the enzymes used. The frequencies of mtDNA types were used to compute genetic distances between Finns, Italians, and Israeli Jews. The frequencies of both enzyme morphs and mtDNA types show that the Finnish population is highly homogeneous.     

Antigen-presenting cell-T cell interaction in the chicken is MHC class II antigen restricted

The involvement of the MHC in the recognition of Ag by avian T lymphocytes was analyzed. PBL from chickens primed with keyhole limpet hemocyanin in vivo were induced to synthesize DNA in an in vitro response to specific Ag. Responding cells were T cells as judged by immunofluorescence staining. In vivo Ag-primed PBL were stimulated in vitro with specific Ag and further propagated in the presence of IL-2. Subsequent Ag-specific T cell proliferation required the presence of Ag-pulsed peripheral blood adherent cells (APC). T cell responses were restricted by the MHC of the APC; Ag presented by allogeneic APC did not support T cell proliferation. By using MHC-recombinant chicken lines, the gene products controlled by MHC class II loci were shown to restrict the T cell-APC interaction. This conclusion was substantiated by the inhibition of the Ag-specific T cell response by a mAb against chicken MHC class II gene products but not by a mAb against chicken MHC class I gene products.     

Flow cytometric DNA analysis combined with fine needle aspiration biopsy in the diagnosis of palpable metastases

To determine the diagnostic value of flow cytometric (FCM) DNA analysis in combination with fine needle aspiration (FNA) biopsy, the nuclear DNA content was analyzed in FNA specimens from 155 superficial metastases and 60 benign lymph nodes. The results of FCM DNA analysis were considered to be positive for malignancy if DNA aneuploidy was found or if more than 12% S+G2M cells were present in the aspirate in diploid cases. The diagnostic accuracy of FCM DNA analysis alone in detecting malignancy was 92%, with a sensitivity of 91% and a specificity of 95%. FCM suggested the correct diagnosis in 5 of the 7 cytologically false-negative cases and in 9 of the 12 cytologically indeterminate or suspicious cases.     

FGFR-4, a novel acidic fibroblast growth factor receptor with a distinct expression pattern.

We have previously identified two novel members of the fibroblast growth factor receptor (FGFR) gene family expressed in K562 erythroleukemia cells. Here we report cDNA cloning and analysis of one of these genes, named FGFR-4. The deduced amino acid sequence of FGFR-4 is 55% identical with both previously characterized FGFRs, flg and bek, and has the structural characteristics of a FGFR family member including three immunoglobulin-like domains in its extracellular part. Antibodies raised against the carboxy terminus of FGFR-4 detected 95 and 110 kd glycoproteins with a protein backbone of 88 kd in COS cells transfected with a FGFR-4 cDNA expression vector. The FGFR-4 protein expressed in COS cells could also be affinity-labeled with radioiodinated acidic FGF. Furthermore, ligand binding experiments demonstrated that FGFR-4 binds acidic FGF with high affinity but does not bind basic FGF. FGFR-4 is expressed as a 3.0 kb mRNA in the adrenal, lung, kidney, liver, pancreas, intestine, striated muscle and spleen tissues of human fetuses. The expression pattern of FGFR-4 is distinct from that of flg and bek and the yet additional member of the same gene family, FGFR-3, which we have also cloned from the K562 leukemia cells. Our results suggest that FGFR-4 along with other fibroblast growth factor receptors performs cell lineage and tissue-specific functions.