Aquatic connectivity: challenges and solutions in a changing climate

The challenge of managing aquatic connectivity in a changing climate is exacerbated in the presence of additional anthropogenic stressors, social factors, and economic drivers. Here we discuss these issues in the context of structural and functional connectivity for aquatic biodiversity, specifically fish, in both the freshwater and marine realms. We posit that adaptive management strategies that consider shifting baselines and the socio-ecological implications of climate change will be required to achieve management objectives. The role of renewable energy expansion, particularly hydropower, is critically examined for its impact on connectivity. We advocate for strategic spatial planning that incorporates nature-positive solutions, ensuring climate mitigation efforts are harmonized with biodiversity conservation. We underscore the urgency of integrating robust scientific modelling with stakeholder values to define clear, adaptive management objectives. Finally, we call for innovative monitoring and predictive decision-making tools to navigate the uncertainties inherent in a changing climate, with the goal of ensuring the resilience and sustainability of aquatic ecosystems.

Effects of preservation by ethanol on δ13 C and δ15 N of three tissues of the critically endangered European eel Anguilla anguilla

The temporal effects of ethanol preservation on the δ¹³ C and δ¹⁵ N values of tissues excised from European eel Anguilla anguilla were assessed. Preservation significantly enriched ¹³ C values of fin and mucus but not dorsal muscle. The ¹³ C enrichment occurred in the initial 15 days of preservation and was independent of initial eel mass. Tissue preservation effects on δ¹⁵ N values were negligible. These tissue-specific isotopic shifts should be considered when ethanol-preserved eel samples are used.

Non-lethal sampling for the stable isotope analysis of the critically endangered European eel Anguilla anguilla: how fin and mucus compare to dorsal muscle

Ecological studies on the critically endangered European eel Anguilla anguilla often incorporate stable isotope analysis that typically uses dorsal muscle sampled from euthanised eels. To minimise the lethal sampling of imperilled populations, fin tissue and/or epidermal mucus can provide non-lethal alternatives to muscle. The results here indicate that δ¹³ C and δ¹⁵ N values of both eel fin and mucus are not significantly different from those of muscle and can be applied directly in comparative SI studies.

First report of root-knot nematodes (Meloidogyne species) infecting Chinese Elm (Ulmus parvifolia) in Florida, USA

Samples of galled roots, resembling those induced by root-knot nematodes, and rhizosphere soil were collected from potted plants of Ulmus parvifolia cvs. Allee and Drake in Lake County, Florida. Nematode species were identified using both molecular analysis and morphology of perineal patterns. Meloidogyne enterolobii and M. javanica were identified from U. parvifolia cv. Allee. Meloidogyne arenaria and M. javanica were identified from U. parvifolia cv. Drake. This is a first report of these nematode species infecting Chinese Elm in Florida.

First report of Meloidogyne enterolobii infecting Japanese blue berry tree (Elaeocarpus decipiens) in Florida, USA

In October 2019, samples of galled roots with rhizosphere soil were collected from declining Elaeocarpus decipiens in Hernando County, Florida. Extracted root-knot nematodes were identified by both molecular and morphological methods as Meloidogyne enterolobii. This is a first report of this regulated root-knot nematode on Elaeocarpus decipiens in Florida.

The interplay between total mercury, methylmercury and dissolved organic matter in fluvial systems: A latitudinal study across Europe

Large-scale studies are needed to identify the drivers of total mercury (THg) and monomethyl-mercury (MeHg) concentrations in aquatic ecosystems. Studies attempting to link dissolved organic matter (DOM) to levels of THg or MeHg are few and geographically constrained. Additionally, stream and river systems have been understudied as compared to lakes. Hence, the aim of this study was to examine the influence of DOM concentration and composition, morphological descriptors, land uses and water chemistry on THg and MeHg concentrations and the percentage of THg as MeHg (%MeHg) in 29 streams across Europe spanning from 41°N to 64 °N. THg concentrations (0.06-2.78 ng L^-1) were highest in streams characterized by DOM with a high terrestrial soil signature and low nutrient content. MeHg concentrations (7.8-159 pg L^-1) varied non-systematically across systems. Relationships between DOM bulk characteristics and THg and MeHg suggest that while soil derived DOM inputs control THg concentrations, autochthonous DOM (aquatically produced) and the availability of electron acceptors for Hg methylating microorganisms (e.g. sulfate) drive %MeHg and potentially MeHg concentration. Overall, these results highlight the large spatial variability in THg and MeHg concentrations at the European scale, and underscore the importance of DOM composition on mercury cycling in fluvial systems.

Role of endoplasmic reticulum stress induction by the plant toxin, persin, in overcoming resistance to the apoptotic effects of tamoxifen in human breast cancer cells

Background:

Persin is a plant toxin that displays synergistic cytotoxicity with tamoxifen in human breast cancer cell lines. Here, we examined the ability of persin to circumvent tamoxifen resistance and delineated the intracellular signalling pathways involved.

Methods:

The induction of apoptosis in tamoxifen-resistant and -sensitive breast cancer cells was measured by flow cytometry following treatment with persin±tamoxifen. Markers of endoplasmic reticulum stress (ERS) were analysed following treatment, and their causal role in mediating persin-induced apoptosis was determined using chemical inhibitors and RNA interference.

Results:

Cells that were resistant to an apoptotic concentration of tamoxifen maintained an apoptotic response to persin. Persin-induced apoptosis was associated with an increase in markers of ERS, that is, CHOP expression and XBP-1 splicing and was decreased by CHOP siRNA. The CASP-4 inhibitor Z-YVAD-FMK markedly inhibited persin-induced apoptosis in both tamoxifen-sensitive and -resistant cells.

Conclusion:

The cytotoxic effects of persin are CASP-4 dependent and mediated by CHOP-dependent and -independent ERS signalling cascades. Increased ERS signalling contributes to persin-induced reversal of tamoxifen resistance.

Identification of subdominant cytotoxic T lymphocyte epitopes encoded by autologous HIV type 1 sequences, using dendritic cell stimulation and computer-driven algorithm

Conventional analysis of the cytotoxic T lymphocyte (CTL) response to HIV-1 may underestimate the true breadth of CTL epitopes recognized. This underestimation could be due to several reasons, including (1) the use of laboratory-adapted stains of HIV or consensus sequences, which would lead to the identification of only highly conserved epitopes, (2) the use of EBV-transformed B cells (B-LCLs) and vaccinia virus constructs in standard assays that may obscure low level CTL responses due to high EBV or vaccinia reactivity, and (3) relatively insensitive assays wherein PBMCs instead of professional APCs are used to stimulate CTL responses. To address these problems, we first identified an immunodominant HLA-B7-restricted CTL epitope, by standard cloning methods, in a long-term nonprogressor (LTNP). To determine whether the patient had CTLs specific for autologous viral sequences other than the dominant epitope, proviral DNA was cloned and sequenced. A matrix-based epitope algorithm (EpiMatrix) was used to identify the top 2% of peptides from the viral sequences with the highest likelihood of binding to HLA-B7. These 55 peptides were synthesized and tested for HLA-B7 binding in a T2/B7 cell line; 10 peptides were able to stabilize HLA-B7 on the cell surface. By using peptide-pulsed autologous dendritic cells as a more sensitive method of CTL stimulation, we found three additional subdominant CTL epitopes.

Longitudinal and cross-sectional analysis of cytotoxic T lymphocyte responses and their relationship to vertical human immunodeficiency virus transmission. ARIEL Project Investigators

The ARIEL Project for the Prevention of HIV Transmission from Mother to Infant was established to evaluate virologic and immunologic parameters during vertical transmission. To determine the strength and breadth of the cytotoxic T lymphocyte (CTL) response and its correlation with human immunodeficiency virus (HIV) transmission, a cross-sectional study was done of 31 HIV-infected pregnant women, of whom 15 transmitted and 16 did not transmit HIV to their infants. The precursor frequencies of CTL specific for HIV-1 gag, pol, nef, and env from 5 different isolates of the clade B of HIV-1 were determined by limiting dilution analysis. Results showed that variable levels of HIV-specific CTL response were present in HIV-infected pregnant women during and after pregnancy. In addition, CTL precursor frequencies specific for pol and nef were higher during pregnancy in nontransmitters than in transmitters. Thus, CTL responding to different HIV antigens may not be contributing equally to the prevention of vertical transmission.

The effect of overnight storage of leukapheresis stem cell products on cell viability, recovery, and cost

The cost of harvesting, processing, and freezing multiple peripheral blood stem cell (PBSC) products could easily exceed that of bone marrow harvest. To reduce costs while maintaining product viability, we examined the effect of overnight storage on PBSC products. Sixteen consecutive leukapheresis samples from 12 patients were examined prospectively. Each initial leukapheresis product was stored overnight on ice (median temperature 15 degrees C) after adding an equal amount of M199 culture medium containing heparin. After overnight storage, the product was combined with the next day PBSC harvest if required and processed/frozen per protocols. Parameters measured before and after storage include cell count and differential, viability, bacterial cultures, and colony-forming unit (CFU) assays. The results show that the median cell concentration during storage was 7.12 x 10(7)/ml and the median length of storage was 20 h. After storage, the median viability and nucleated cell recovery were 100% and 99.5%, respectively. In addition, 98% recovery of CFU-GM was achieved. No clotting or bacterial contamination was detected. All 12 patients studied engrafted promptly. In addition, 124 similarly treated patients were retrospectively analyzed. Of these, 48% required > or = 2 large-volume leukaphereses to achieve the target cell dose. As a result of overnight storage, 150 final products, instead of 224, were processed and cryopreserved. This difference is equivalent to 33% cost savings. Again, all patients were transplanted and engrafted successfully. In conclusion, overnight storage and pooling of two consecutive PBSC products are safe, reduce cost, and allow for optimum laboratory staffing.

Measurement of absolute concentration and viability of CD34+ cells in cord blood and cord blood products using fluorescent beads and cyanine nucleic acid dyes

Conventional flow cytometric methods for CD34+ cell counting may be affected by the high number of nucleated red blood cells or nonviable cells in cord blood and its products. We developed a simple flow cytometric no-wash procedure that avoids these shortcomings because it provides absolute CD34+ cell counts and assesses cell viability. Samples were incubated with phycoerythrin (PE)-labeled anti-CD34 (Becton Dickinson Immunocytometry Systems [BD], San Jose, CA) and peridinin chlorophyll protein (PerCP)-labeled anti-CD45 (BD) in bead-containing TRUCOUNT tubes (BD). After red cell lysis with a fixative-free reagent, the impermeant nucleic acid dye YO-PRO-1 (Molecular Probes, Eugene, OR) was added and samples were analyzed on a single-laser FACSCalibur (BD). A comparison with the ProCOUNT progenitor cell assay (BD) in 57 samples revealed excellent correlation of results (r = 0.98, intercept -0.2 cells/microl, slope 1.01). Precision studies conveyed coefficients of variation of 6.4 and 8.9% at concentrations of 35 and 16 CD34+ cells/microl, respectively. In untreated and leukocyte-enriched cord blood 4.5+/-3.8% of CD34+ cells were stained by YO-PRO-1, representing apoptotic or necrotic cells. In post-thawing cryopreserved samples this number increased to 10.4+/-5.5%. Isotype controls showed very low blank values of viable cells (0.1+/-0.4 cells/microl, maximum 2.4) and seemed unnecessary. We found no washing-related alteration of results in 35 samples, indicating that the method may also be performed with cell washing. Replacing YO-PRO-1 with TO-PRO-3 facilitated four-color analysis of subpopulations of viable CD34+ cells on a FACSCalibur equipped with a second (diode) laser. We found the proposed method to be a rapid, efficient, and flexible procedure that improved validity of CD34+ cell counts.

Prediction of HIV peptide epitopes by a novel algorithm

Identification of promiscuous or multideterminant T cell epitopes is essential for HIV vaccine development, however, current methods for T cell epitope identification are both cost intensive and labor intensive. We have developed a computer-driven algorithm, named EpiMer, which searches protein amino acid sequences for putative MHC class I- and/or class II-restricted T cell epitopes. This algorithm identifies peptides that contain multiple MHC-binding motifs from protein sequences. To evaluate the predictive power of EpiMer, the amino acid sequences of the HIV-1 proteins nef, gp160, gag p55, and tat were searched for regions of MHC-binding motif clustering. We assessed the algorithm's predictive power by comparing the EpiMer-predicted peptide epitopes to T cell epitopes that have been published in the literature. The EpiMer method of T cell epitope identification was compared to the standard method of synthesizing short, overlapping peptides and testing them for immunogenicity (overlapping peptide method), and to an alternate algorithm that has been used to identify putative T cell epitopes from primary structure (AMPHI). For the four HIV-1 proteins analyzed, the in vitro testing of EpiMer peptides for immunogenicity would have required the synthesis of fewer total peptides than either AMPHI or the overlapping peptide method. The EpiMer algorithm proved to be more efficient and more sensitive per amino acid than both the overlapping peptide method and AMPHI. The EpiMer predictions for these four HIV proteins are described. Since EpiMer-predicted peptides have the potential to bind to multiple MHC alleles, they are strong candidates for inclusion in a synthetic HIV vaccine.

Increase in the rate of diploidy with maternal age in unfertilized in-vitro fertilization oocytes

Human oocytes which failed to fertilize in vitro were fixed for cytogenetic analysis. Metaphase II chromosomes were identified in 286 oocytes, of which 233 were suitable for cytogenetic analysis. In all, 181 oocytes had a normal haploid karyotype (77.7%), while the remaining 52 were abnormal (28 aneuploid, 14 diploid and 10 tetraploid). The rate of aneuploidy did not increase with maternal age. However, the proportion of diploid oocytes increased significantly with advancing maternal age (P < 0.01), being particularly obvious in women aged > 35 years.

Two novel T cell epitope prediction algorithms based on MHC-binding motifs; comparison of predicted and published epitopes from Mycobacterium tuberculosis and HIV protein sequences

We have designed two computer-based algorithms for T cell epitope prediction, OptiMer and EpiMer, which incorporate current knowledge of MHC-binding motifs. OptiMer locates amphipathic segments of protein antigens with a high density of MHC-binding motifs. EpiMer identifies peptides with a high density of MHC-binding motifs alone. These algorithms exploit the striking tendency for MHC-binding motifs to cluster within short segments of each protein. Putative epitopes predicted by these algorithms contain motifs corresponding to many different MHC alleles, and may contain both class I and class II motifs, features thought to be ideal for the peptide components of synthetic subunit vaccines. In this study, we describe the use of OptiMer and EpiMer for the prediction of putative T cell epitopes from Mycobacterium tuberculosis and human immunodeficiency virus protein antigens, and demonstrate that these two algorithms may provide sensitive and efficient means for the prediction of promiscuous T cell epitopes that may be critical to the development of vaccines against these and other pathogens.

Premature ovarian failure and ovarian dysgenesis associated with balanced and unbalanced X-6 translocations, respectively: implications for the investigation of ovarian failure

This study reports the effect of an inherited (X;6) translocation which has not previously been described. The proband was intellectually delayed and had ovarian dysgenesis. Karyotyping revealed an unbalanced karyotype: 46,X,der(X)t(X;6)(q22; p11.2)*. Her mother was shown to be a carrier of an apparently balanced translocation between the X chromosome and chromosome 6: 46,X,t(X;6)(q22;p11.2). This finding in the mother raises to 7 the number of cases reported which involve a break within the X chromosome 'critical region', at band Xq22, without causing ovarian dysgenesis, although it was associated with premature ovarian failure. These cases aim to highlight to clinical specialists the range of gonadal and other phenotypic anomalies (apart from those associated with Turner syndrome) which can occur due to partial deletions of the X chromosome. These findings have implications for the investigation of both ovarian dysgenesis and premature ovarian failure.

Use of pulsed electromagnetic fields in treatment of loosened cemented hip prostheses. A double-blind trial

A double-blind trial of pulsed electromagnetic fields (PEMFs) for loosened cemented hip prostheses was conducted at two centers. Of the 40 patients who enrolled, 37 met entry criteria and were available for analysis. All patients completed six months of treatment (either active or control units). Success was determined clinically by a Harris hip score greater than or equal to 80 points (or an increase of ten points if initially greater than or equal to 70 points). Ten of the 19 active units were successes (53%), whereas two of the 18 controls (11%) exhibited a placebo effect, a statistically significant and clinically relevant result. A 60% relapse rate among the active successes was seen at 14 months poststimulation, and despite maintenance therapy of one hour per day, the relapse rate increased to 90% at three years. These data suggest that for loosened cemented hip prostheses, use of PEMFs is a treatment option only to delay revision hip surgery.

Sterilization of a small caliber vascular graft with a polyexpoxy compound

Sterilization of tissue based medical devices via cold sterilization processes has been limited to formaldehyde, glutaraldehyde, and mixtures of the same with alcohols and surfactants. The authors report the sterilization of a small caliber vascular graft with a combination of diglycidyl ether and ethanol. The sterilant contains 1-4% diglycidyl ether and 10-20% ethanol as an aqueous solution. Sterilization is achieved after exposure of the graft to the sterilant solution for a period of 7 days at an elevated temperature (30 degrees - 40 degrees C). The biologic indicator selected for efficacy studies was Bacillus subtilis niger ATCC 9372 (endospores). The grafts were inoculated with a concentrated endospore suspension and immersed in the sterilant solution for increasing time periods. After extensive rinsing over membrane filters to remove any residual sterilant, the grafts and filters were cultured in tryptic soy broth. D10 values were calculated using a fraction-negative, most probable number technique. Additionally, many representative bacteria and fungi were tested and found to be susceptible to the new sterilant developed. The diglycidyl ether/alcohol sterilant developed was found to be efficacious for sterilization of the tissue based vascular grafts tested.

Metabolic and developmental responses of preimplantation embryos to platelet activating factor (PAF)

Platelet activating factor (PAF) is an ether phospholipid produced by preimplantation embryos of a number of species. Production of PAF by embryos has been measured by detecting thrombocytopenia in a splenectomized mouse bioassay, platelet aggregation bioassays in vitro and a specific radioimmunoassay. Production is highly variable and is adversely affected by culture in vitro. It has, however, been correlated with morphology, development rates in vitro and the pregnancy potential of embryos following transfer. Investigations using PAF-antagonists have established an essential role for PAF in early pregnancy. Together with studies that have shown PAF to have direct effects on embryonic metabolism during culture in vitro, these observations suggest that PAF acts as an embryonic autocoid. Hence, a major site of action for embryo-derived PAF in vivo is the embryo itself. Supplementation of embryo culture media with PAF had no effect on the rate of development in vitro of 2-cell mouse embryos through to the blastocyst stage. However, PAF increased cell numbers of blastocysts cultured from the 2-cell stage and the mitotic index of embryos at both the 8-cell and blastocyst stages. Supplementation of culture media with PAF has also been shown to increase the implantation potential of both mouse and human embryos cultured in vitro. In the mouse, the effect of PAF in enhancing implantation rates was most evident when the developmental potential of untreated embryos was suboptimal. These observations suggest that the production of embryo-derived PAF is one limiting factor in maintaining the viability of embryos cultured in vitro.

Cytogenetic study of solid ovarian tumors

With the use of a short-term tissue culture method, 27 solid ovarian tumor specimens (from 22 patients) were successfully karyotyped. The majority of the specimens were from serous carcinoma (18 specimens, 2 of which were not invasive). Adenocarcinomas (two specimens), two endometrioid carcinomas, and one each of clear cell, mucinous, sarcoma, squamous carcinoma, and an unclassified sex cord carcinoma were also analyzed. The specimens showed marked cytogenetic heterogeneity, ranging from a normal karyotype (46,XX) to very grossly aneuploid, with multiple rearrangements. All chromosomes, excepting 13, 15, 19, 20, and 21 were positively identified in at least one rearrangement. Chromosomes 1, 6, and 7 were most commonly involved. Identified rearrangements were not limited to one carcinoma type. The most common deletions of 1p and 6q were identified in both serous carcinoma and adenocarcinoma. Deletion of 7q,(del(7)(q32)), was observed only in serous carcinoma but was limited to three patients. Correlations of modal chromosome count and number of marker chromosomes appeared to be associated with good prognosis for patients with serous carcinoma.

Analysis of inferred cytogenetic clonal evolution in a metastatic human ovarian carcinoma

Cytogenetic analyses of solid tumors are hampered both by the difficulties in preparing high-quality banded metaphases and the high degree of karyotypic heterogeneity. Three specimens were obtained from a single patient with serous carcinoma for karyotyping and compared to determine whether the tumor was multifocal or metastatic. All three specimens were hypodiploid, sharing marker chromosomes, thus indicating metastasis. To simplify comparison between the specimens, a diagram of the inferred cytogenetic evolution of the cells analysed was developed. This method afforded a simple means of comparing the different tumor sites in a single patient and might also be applied to sequential samples from patients.

A simplified method for fixation of human and mouse preimplantation embryos which facilitates G-banding and karyotypic analysis

A reliable method for the fixation of large numbers of preimplantation embryos was developed to allow application of routine G-banding methods to preimplantation stage embryos. The technique resulted in minimal loss of embryos and was suitable for both 1-cell mouse embryos and multi-pronuclear human embryos. Application of this method will increase the information gained from chromosome studies of embryonic development.

High quality metaphases from solid ovarian tumors

Cytogenetic studies of human solid tumor tissue are hampered by poor quality preparations. Using a method of short-term tissue culture developed for ovarian carcinoma specimens, we have obtained large numbers of high quality metaphases suitable for analysis from 19 of 28 ovarian tumors studied.

Contribution of reciprocal translocations to an understanding of chromosome displacement: inferences for studies of spatial order at metaphase

Chromosome displacement was analysed in three different translocations. Two alternative hypotheses were examined: (1) Displacement is determined by the spatial ordering of chromosomes on the metaphase plate. (2) Displacement is a function of the gross physical property of chromosome size and does not reflect ordering. Predicted numbers of displacements were calculated for each chromosome for each of the two hypotheses and these were compared with the observed numbers of displacements using a chi 2 analysis. In the analysis for two of the three translocations, the first hypothesis was rejected whilst the alternative hypothesis was supported by all three analyses. It is concluded that chromosome displacement is a function of chromosome size and does not reflect spatial ordering at metaphase. Furthermore, it is suggested that many studies of apparent ordering at metaphase may merely reflect chromosome displacement. The analysis of displacement rates in all other chromosomes of the complement was undertaken in one of the translocation carriers. This showed no alteration of relative displacement rates.

Interactions between C-bands of chromosomes 1 and 9 in recurrent reproductive loss

The size of the heterochromatic regions of chromosomes 1 and 16 was measured in a Test group of women with histories of recurrent spontaneous abortion and a Control group of fertile women. Measurements were made on Giemsa banded preparations and the euchromatic regions of 1q and 16q were used to correct for between-cell contraction. For each chromosome pair, the larger and smaller chromosome was identified and populations of each were compared between the two subject groups. For chromosome 1, the smaller chromosome of the Test group was significantly smaller than that of the Control group (P less than 0.001) and the size of the pair difference was larger in the Test than in the Control group (P less than 0.01). For chromosome 16, the smaller chromosome of the Test group was smaller than that of the Control group (5% level). The interaction of chromosome 1 and chromosome 9 heterochromatin in each individual has been analyzed. The combined score for the smaller chromosome 1 and the larger chromosome 9 shows a bimodal distribution and allows discrimination between the two subject groups. Various possible ways in which this interaction might affect reproductive outcome are discussed.

Within pair differences of human chromosome 9 C-bands associated with reproductive loss

The size and position of the heterochromatic regions of chromosome 9 were examined in a group of women with histories of recurrent miscarriage and a control group of fertile women. Measurements were made on whole chromosomes (variability between chromosomes was taken to reflect differences in heterochromatin), and corrections for between-cell contraction were made by comparison with chromosome 7. Chromosomes were analysed in pairs and the following results were obtained: (1) The larger of the pairs of chromosomes of the test group were significantly larger than those of the control group: (2) The smaller of the pairs of chromosomes were the same in each group: (3) The differences between the chromosome pairs were significantly greater in the test than the control group: and (4) The sums of the homologous chromosomes were significantly greater in the test than in the control group. Independent assessment also showed that a significantly higher frequency of complete pericentric inversions of chromosome 9 was present in the test than the control group. These results are discussed in the light of two hypotheses: (1) The difference in the size of the homologous chromosomes is critical, and (2) the total heterochromatic content of a chromosome and/or cell is critical. Some evidence is presented to support each hypothesis, but the former is the more favoured by the data.