Historical stocking data and 19th century DNA reveal human-induced changes to native diversity and distribution of cutthroat trout.

Many species are threatened with extinction and efforts are underway worldwide to restore imperilled species to their native ranges. Restoration requires knowledge of species' historical diversity and distribution. For some species, many populations were extirpated or individuals moved beyond their native range before native diversity and distribution were documented, resulting in a lack of accurate information for establishing restoration goals. Moreover, traditional taxonomic assessments often failed to accurately capture phylogenetic diversity. We illustrate a general approach for estimating regional native diversity and distribution for cutthroat trout in the Southern Rocky Mountains. We assembled a large archive of historical records documenting human-mediated change in the distribution of cutthroat trout (Oncorhynchus clarkii) and combined these data with phylogenetic analysis of 19th century samples from museums collected prior to trout stocking activities and contemporary DNA samples. Our study of the trout in the Southern Rocky Mountains uncovered six divergent lineages, two of which went extinct, probably in the early 20th century. A third lineage, previously declared extinct, was discovered surviving in a single stream outside of its native range. Comparison of the historical and modern distributions with stocking records revealed that the current distribution of trout largely reflects intensive stocking early in the late 19th and early 20th century from two phylogenetically and geographically distinct sources. Our documentation of recent extinctions, undescribed lineages, errors in taxonomy and dramatic range changes induced by human movement of fish underscores the importance of the historical record when developing and implementing conservation plans for threatened and endangered species.

Evidence that chytrids dominate fungal communities in high-elevation soils.

Periglacial soils are one of the least studied ecosystems on Earth, yet they are widespread and are increasing in area due to retreat of glaciers worldwide. Soils in these environments are cold and during the brief summer are exposed to high levels of UV radiation and dramatic fluctuations in moisture and temperature. Recent research suggests that these environments harbor immense microbial diversity. Here we use sequencing of environmental DNA, culturing of isolates, and analysis of environmental variables to show that members of the Chytridiomycota (chytrids) dominate fungal biodiversity and perhaps decomposition processes in plant-free, high-elevation soils from the highest mountain ranges on Earth. The zoosporic reproduction of chytrids requires free water, yet we found that chytrids constituted over 70% of the ribosomal gene sequences of clone libraries from barren soils of the Himalayas and Rockies; by contrast, they are rare in other soil environments. Very few chytrids have been cultured, although we were successful at culturing chytrids from high-elevation sites throughout the world. In a more focused study of our sites in Colorado, we show that carbon sources that support chytrid growth (eolian deposited pollen and microbial phototrophs) are abundant and that soils are saturated with water for several months under the snow, thus creating ideal conditions for the development of a chytrid-dominated ecosystem. Our work broadens the known biodiversity of the Chytridomycota, and describes previously unsuspected links between aquatic and terrestrial ecosystems in alpine regions.

A bioavailable strontium (87Sr/86Sr) isoscape for Aotearoa New Zealand: Implications for food forensics and biosecurity.

As people, animals and materials are transported across increasingly large distances in a globalized world, threats to our biosecurity and food security are rising. Aotearoa New Zealand is an island nation with many endemic species, a strong local agricultural industry, and a need to protect these from pest threats, as well as the economy from fraudulent commodities. Mitigation of such threats is much more effective if their origins and pathways for entry are understood. We propose that this may be addressed in Aotearoa using strontium isotope analysis of both pests and products. Bioavailable radiogenic isotopes of strontium are ubiquitous markers of provenance that are increasingly used to trace the origin of animals and plants as well as products, but currently a baseline map across Aotearoa is lacking, preventing use of this technique. Here, we have improved an existing methodology to develop a regional bioavailable strontium isoscape using the best available geospatial datasets for Aotearoa. The isoscape explains 53% of the variation (R2 = 0.53 and RMSE = 0.00098) across the region, for which the primary drivers are the underlying geology, soil pH, and aerosol deposition (dust and sea salt). We tested the potential of this model to determine the origin of cow milk produced across Aotearoa. Predictions for cow milk (n = 33) highlighted all potential origin locations that share similar 87Sr/86Sr values, with the closest predictions averaging 7.05 km away from their true place of origin. These results demonstrate that this bioavailable strontium isoscape is effective for tracing locally produced agricultural products in Aotearoa. Accordingly, it could be used to certify the origin of Aotearoa's products, while also helping to determine if new pest detections were of locally breeding populations or not, or to raise awareness of imported illegal agricultural products.

Future intensification of extreme Aleutian low events and their climate impacts.

Extreme Aleutian Low (AL) events have been associated with major ecosystem reorganisations and unusual weather patterns in the Pacific region, with serious socio-economic consequences. Yet, their future evolution and impacts on atmosphere-ocean interactions remain uncertain. Here, a large ensemble of historical and future runs from the Community Earth System Model is used to investigate the evolution of AL extremes. The frequency and persistence of AL extremes are quantified and their connection with climatic variables is examined. AL extremes become more frequent and persistent under the RCP8.5 scenario, associated with changes in precipitation and air temperature patterns over North America. Future changes in AL extremes also increase the variability of the sea surface temperature and net heat fluxes in the Kuroshio Extension, the most significant heat and energy flux region of the basin. The increased frequency and persistence of future AL extremes may potentially cause substantial changes in fisheries and ecosystems of the entire Pacific region as a knock-on effect.

The influence of viral infection on a plankton ecosystem undergoing nutrient enrichment.

It is increasingly recognised that viruses are a significant active component of oceanic plankton ecosystems. They play an important role in biogeochemical cycles as well as being implicated in observed patterns of species abundance and diversity. The influence of viral infection in plankton ecosystems is not fully understood. Here we use a number of well-founded mathematical models to investigate the interplay of the ecological and epidemiological interactions of plankton and viruses in the sea. Of particular interest is the role of nutrient on the population dynamics. Nutrient forcing has been suggested as a means of absorbing excess anthropogenic atmospheric carbon dioxide by stimulating increased phytoplankton primary productivity. Here we show that enriching nutrient levels in the sea may decrease the amount of infected phytoplankton species thereby additionally enhancing the efficiency of the biological pump, a means by which carbon is transferred from the atmosphere to the deep ocean.

A hydrochemically guided landscape classification system for modelling spatial variation in multiple water quality indices: Process-attribute mapping.

Spatial variation in landscape attributes can account for much of the variability in water quality relative to land use on its own. Such variation results from the coupling between the dominant processes governing water quality, namely hydrological, redox, and weathering and gradients in key landscape attributes, such as topography, geology, and soil drainage. Despite the importance of 'process-attribute' gradients (PAG), few water quality models explicitly account for their influence. Here a processes-based water quality modelling framework is presented that more completely accounts for the role of landscape variability over water quality - Process-Attribute Mapping (PoAM). Critically, hydrochemical measures form the basis for the identification and mapping of effective landscape attributes, producing PAG maps that attempt to replicate the natural landscape gradients governing each dominant process. Application to the province of Southland (31,824 km2), New Zealand, utilised 12 existing geospatial datasets and a total of 28,626 surface water, groundwater, spring, soil water, and precipitation analyses to guide the identification and mapping of 11 individual PAG. The ability of PAGs to replicate regional hydrological, redox, and weathering gradients was assessed on the accuracy with which the hydrochemical indicators of each dominant process (e.g. hydrological tracers, redox indicators) were estimated across 93 long-term surface water monitoring sites (cross-validated R2 values of 0.75-0.95). Given hydrochemical evidence that PAGs replicate actual landscape gradients governing the dominant processes, they were combined with a land use intensity layer and used to estimate steady-state surface water quality. Cross-validated R2 values ranged between 0.81 and 0.92 for median total nitrogen, total oxidised nitrogen, total phosphorus and dissolved reactive phosphorus. Models of particulate species E. coli and total suspended sediment, although reasonable (R2 0.72-0.73), were less accurate, suggesting finer-grained land use, landscape attribute, and/or flow normalised measures are required to improve estimation.

Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution in adult liver transplantation.

BACKGROUND: A safe and effective preservation solution is a precondition for successful orthotopic liver transplantation (OLT). This study compared University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions in OLT. PATIENTS AND METHODS: We retrospectively reviewed the medical records of 137 primary cadaveric. OLT performed between January 2003 and December 2006 at our institution. Sixty-eight grafts were harvested using UW and 69 using HTK. Recipients were managed similarly in regard to operative techniques and immunosuppression. We collected donor data including serum transaminases, serum sodium, ICU stay and assessed macroscopic liver quality. Recipient serum transaminases were collected on postoperative days 1, 7, 14, and 30. We compared biliary and vascular complications, as well as patient and graft survivals. RESULTS: Mean serum bilirubin levels were slightly higher in the HTK group at 1,7,14, and 30 days after transplantation, whereas transaminases were higher in the UW group. Primary nonfunction occurred in 1 patient in each group. Retransplantation was performed in 5 patients in the UW and in 9 patients in the HTK group. Biliary complication rates were similar in the UW and HTK groups (22% and 17%, respectively). Six arterial complications occurred in the HTK (8.7%) and 2 in the UW group (2.9%; P < .05). Mean follow-up was 25 months. Graft survival at 1, 12, and 36 months was 90%, 78%, and 75% versus 90%, 71%, and 71% in the UW versus HTK groups, respectively. One-, 12-, and 36-month patient survival rates were 93%, 78%, and 75% versus 93%, 78%, and 78% in the UW versus HTK groups, respectively. CONCLUSIONS: There were no significant differences in graft and patient survivals between the 2 groups. Whereas the biliary complication rates were comparable in both groups, the arterial complications were clearly higher in the UW group (8.7% vs 2.9%; P < .05%). UW and HTK solutions seemed to be equally safe and effective in the preservation of liver grafts. The high incidence of arterial complications in the UW group requires further prospective studies.

Contact X-ray Brachytherapy as an Adjunct to a Watch and Wait Approach is an Affordable Alternative to Standard Surgical Management of Rectal Cancer for Patients with a Partial Clinical Response to Chemoradiotherapy.

AIMS: Emerging evidence suggests that contact X-ray brachytherapy (CXB) may increase the clinical complete response rate and durability when administered after standard chemoradiotherapy in patients with rectal cancer. The addition of CXB in partial responders is therefore probably cost-effective. The affordability of widening access to CXB in the UK, however, has not been evaluated. MATERIALS AND METHODS: Decision analytical modelling with Monte Carlo simulation was used to evaluate long-term costs for the management of patients with rectal cancers who were given a CXB boost when a clinical complete response was not initially achieved following chemoradiotherapy in order to facilitate a watch and wait approach. A third-party payer (National Health Service) perspective was adopted, probabilistic sensitivity analysis was carried out and a scenario analysis was performed to investigate the effect of the number of referral centres and number of patients treated with CXB. RESULTS: We estimate that 818 (95% confidence interval 628-1021) patients per year are eligible for CXB as an adjunct to a watch and wait approach in England and Wales. As this management is less costly than surgical management for each individual patient, the more patients treated, the more affordable the technology. Even if as few as 125 patients are treated nationally in 15 centres, the cost of implementing this technology would be less than £4 million. If the average number of patients treated in each centre is 30, this technology would be cost saving within 5 years. CONCLUSIONS: The cost of CXB is not prohibitive according to the National Institute for Health and Care Excellence threshold for implementation of new technology and may even be cost saving within 5 years compared with standard surgical management, depending on the uptake of the technology and the number of referral centres.

A Cost-Effectiveness Analysis of Contact X-ray Brachytherapy for the Treatment of Patients with Rectal Cancer Following a Partial Response to Chemoradiotherapy.

AIMS: Following chemoradiotherapy in patients with rectal cancer, the addition of contact X-ray brachytherapy (CXB) in partial responders might increase the proportion of patients with a clinical complete response (cCR) and who are thus suitable for watch and wait management. However, the long-term cost-effectiveness of this approach has not been evaluated. MATERIALS AND METHODS: Decision analytical modelling and a Markov simulation were used to compare long-term costs, quality-adjusted life years (QALYs) and cost-effectiveness from a third-party payer (National Health Service) perspective for treatment strategies after chemoradiotherapy; watch and wait with CXB when a cCR was not initially achieved after external beam radiotherapy (EBRT) (WWCXB), watch and wait with EBRT alone (WWEBRT) and radical surgery for all patients. The effect of uncertainty in model parameters and patient demographics was investigated. RESULTS: WWCXB had a higher QALY payoff than both radical surgery and WWEBRT and was less costly in most scenarios and demographic cohorts. In all plausible scenarios, WWCXB was the most cost-effective, at a threshold of £20 000/QALY. This finding was insensitive to uncertainty associated with model parameters. CONCLUSIONS: WWCXB is likely to be cost-effective compared with both WWEBRT alone and radical surgery. These findings support the use of CXB boost as an adjunct to a watch and wait strategy.

Overview of the MELD score and the UNOS adult liver allocation system.

On February 27, 2002, the United Network for Organ Sharing (UNOS) introduced a new allocation policy for cadaveric liver transplants, based on the Model for End-Stage Liver Disease (MELD) score. This new policy stratifies the patients based on their risk of death while on the waiting list. We analyzed the background and main features of this new allocation policy to evaluate the effects on waiting list dynamics as well as the accuracy of MELD as a predictor of pretransplantation mortality and posttransplantation outcome. MELD has proved to be accurate as a predictor of waiting list mortality, but seems to be less accurate to predict posttransplantation outcome. Immediate effects of the new policy were a reduction in the waiting list, while organs were primarily directed to sicker patients with reduced waiting times. There was a statistically but not significantly reduced number of patients removed from the list due to death or severity of sickness. The balance between medical urgency and transplant benefit is still to be defined as is the relationship between pretransplantation criteria and posttransplantation outcomes, and the way this relationship should be included in the allocation policy.

Successful staged kidney and liver transplantation for glycogen storage disease type Ib: A case report.

Glycogen storage disease type Ib is a rare metabolic disease caused by a defect of the G6P transporter. Patients suffer from hypoglycemic episodes; growth and developmental delay; osteoporosis; neutropenia; and tendency to infections, ovarian cysts, and liver adenomas. Terminal kidney disease is a rare complication. Liver transplantation has been performed to prevent malignant transformation of hepatic adenomas. We present the case of a female patient with glycogenosis type Ib who had severe hypoglycemic episodes and recurrent infections since early childhood. She became dialysis dependent at the age of 24 years. Kidney transplantation was performed at age 30, and liver transplantation 2 years later. The main indication for liver transplantation were the persistent, therapy-refractory hypoglycemic episodes. The transplanted kidney function is stable. The liver transplantation resulted in the disappearance of hypoglycemic episodes, with the patient leading a normal life and eating a normal diet. The neutropenia did not recover, but there were no more significant infectious episodes after liver transplantation. This is, to the best of our knowledge, the first communication of a dual kidney and liver transplant performed in a patient with glycogenosis type Ib. It confirmed the beneficial effect of liver transplantation on the quality of life of patients with severe hypoglycemia. The transplantation should be attempted earlier in the course of the disease to reduce complications and allow catch-up growth. Hepatocyte transplantation may be considered; however, long-term results seem to be rather poor in the few documented cases.

Influence of Ca2+ on the plasma membrane potential and electrogenic uptake of glycine by myeloma cells. Involvement of a Ca2+-activated K+ channel.

The involvement of Ca2+-activated K+ channels in the regulation of the plasma membrane potential and electrogenic uptake of glycine in SP 2/0-AG14 lymphocytes was investigated using the potentiometric indicator 3,3'-diethylthiodicarbocyanine iodide. The resting membrane potential was estimated to be -57 +/- 6 mV (n = 4), a value similar to that of normal lymphocytes. The magnitude of the membrane potential and the electrogenic uptake of glycine were dependent on the extracellular K+ concentration, [K+]o, and were significantly enhanced by exogenous calcium. The apparent Vmax of Na+-dependent glycine uptake was doubled in the presence of calcium, whereas the K0.5 was not affected. Ouabain had no influence on the membrane potential under the conditions employed. Additional criteria used to demonstrate the presence of Ca2+-activated K+ channels included the following: (1) addition of EGTA to calcium supplemented cells elicited a rapid depolarization of the membrane potential that was dependent on [K+]o; (2) the calmodulin antagonist, trifluoperazine, depolarized the membrane potential in a dose-dependent and saturable manner with an IC50 of 9.4 microM; and (3) cells treated with the Ca2+-activated K+ channel antagonist, quinine, demonstrated an elevated membrane potential and depressed electrogenic glycine uptake. Results from the present study provide evidence for Ca2+-activated K+ channels in SP 2/0-AG14 lymphocytes, and that their involvement regulates the plasma membrane potential and thereby the electrogenic uptake of Na+-dependent amino acids.

Sirolimus conversion after liver transplantation: improvement in measured glomerular filtration rate after 2 years.

METHODS: We reviewed our prospectively maintained database of 2005 liver transplantations. Therapy was either started de novo or converted from calcineurin inhibitors (CNIs) to sirolimus as the main immunosuppressive agent for nephrotoxicity or rejection. Glomerular filtration rate (GFR) was determined with iodine 125-labeled sodium isthalamate (Glofil-125), and serum creatinine concentration was obtained before and 3 months after transplantation, and yearly in both groups. Sirolimus levels were 10 to 15 ng/mL in patients at less than 3 months after transplantations and 5 to 10 ng/mL in the remaining patients. All patients received mycophenolate mofetil as maintenance therapy. RESULTS: Data for 29 patients in the de novo group and 35 in the conversion group were reviewed. Patients in the de novo group demonstrated an acute cellular rejection rate of 17.2%, 40% of which were steroid resistant. In this group, 48.2% discontinuation of sirolimus was necessary because of adverse effects. Patients in the conversion group demonstrated an acute cellular rejection rate of 2.8% and a 34.3% rate of sirolimus discontinuation. Seventeen (56.7%) patients at 1 year and 8 (44.4%) patients at 2 years demonstrated continued improvement in GFR. In the conversion group, case-control analysis did not demonstrate a significant difference in GFR and serum creatinine concentration (P > .05) at 1 and 2 years after conversion. At the time of review, no patients in the conversion group required hemodialysis. CONCLUSIONS: Conversion to sirolimus therapy is an effective strategy in improving renal function in patients with CNI-induced nephrotoxicity and can be done without increased rejection. Most of our patients (65.7%) tolerated sirolimus conversion. Of these, 56.7% and 44.4% demonstrated continued increase in GFR with the CNI-free regimen at 1 and 2 years, respectively. Long-term, large-population, prospective, randomized, controlled studies should further validate these results.

Effect of aging on the oxidative phosphorylation pathway.

The proposed study was undertaken to investigate the effect of aging on control of the oxidative phosphorylation pathway. Flux control coefficients for adenine nucleotide translocase and cytochrome c oxidase were determined using the procedure of Groen et al. [J. Biol. Chem., 257 (1982) 137-144]. Hepatic mitochondrial fractions from Fischer 344 rats were isolated from control (average age 6.5 months), and aged (average age 27.3 months) groups. No aging-related changes in the extent of control of respiration by the oxidase were obtained, however, differences were observed for the translocase. For the control group of animals, the greatest regulation occurred at 80-85% maximal respiratory rates, and declined at higher rates. For the aged group, a similar flux control coefficient was obtained at 80-85% respiration, but was maintained as respiration increased to maximal rates. It is proposed that changes in the flux control coefficients at maximal respiratory rates are associated with an aging-related decrease in translocase activity. Evaluation of translocase content revealed no significant differences between the two groups supporting the concept that the decreased activity was not due to decreased content. During the course of these experiments, it also became apparent that there was a significant aging-related decrease in the rate of succinate oxidation providing an adequate supply of ADP was present. No significant changes in respiratory rates, or RCR, were evident at suboptimal concentrations of ADP as reported previously from this laboratory [Vorbeck, M.L. et al., Arch. Biochem. Biophys., 214 (1982) 67-79]. Since similar decreases in respiration were obtained upon addition of an uncoupler, the aging-related changes in respiration are attributed to differences at the level of the electron transport system, including its associated reactions. The aging-related differences in respiratory rates, and extent of control of respiration, were both observed under conditions of maximal stimulation of respiration. This suggests an inability of mitochondria from aged animals to respond to the increased demands of oxidation. Basic to these differences may be the lipid-membrane associated changes seen during aging.

An ELISA for screening hybridoma cultures for monoclonal antibodies against a detergent solubilized integral membrane protein.

A method is described for the binding of a detergent solubilized integral membrane protein to polystyrene immunoassay plates. Addition of Bouin's fluid, a histochemical fixative, to wells of plates containing the detergent solubilized antigen, followed by low speed centrifugation, is sufficient to promote binding of antigen in the presence of Triton X-100 concentrations as high as 1.75%. The binding of antigen is rapid and the entire binding procedure, including removal of fixative and washing of the plates, can be accomplished in less than 15 min. Immunological specificity of the bound antigen is retained. This method has been used to effectively screen hybridoma cultures for specific antibodies.

Regional endemism and cryptic species revealed by molecular and morphological analysis of a widespread species of Neotropical catfish.

The lower Central American landscape was fully emergent approximately three million years ago, an event which marked the beginning of the Great American biotic interchange. Freshwater fishes participated in the biotic interchange. Because primary freshwater fishes are restricted to freshwater, they provide an excellent system for investigating the interplay of historical and recent processes on the assembly, structure and diversity of the regions' aquatic ecosystems. We focused on examining the history of diversification for a species of catfish (Pimelodella chagresi) whose distribution spans multiple, isolated drainage basins across the Isthmian landscape and into north-western South America. Analysis of mitochondrial DNA haplotypes and morphological traits indicated that P. chagresi, as currently recognized, comprises a species complex. In addition, along the Pacific slope of Panama, repeated dispersion, diversification, extinction and possibly hybridization are thought to underlie a complex distribution of haplotypes. Overall, the results underscore the tremendous importance of historical processes on regional biodiversity.

Metabolism of norethynodre, a 19-nor progestin: subcellular localization of enzyme activity.

PIP: The subcellular distribution of the enzymes involved in the metabolism of norethynodrel (17 alpha-ethynyl-17 beta-hydroxy-estr-5(10)-en-3-one) to the 3alpha and 3beta diols (17 alpha-ethynyl-3alpha (or 3beta-17 beta-dihydroxy-estr-5(10)-ene) and 17 alpha-ethinyl estradiol was studied. The purity of the male rat liver subcellular fractions was evaluated by the use of marker enzymes. Sample sections were viewed by electron microscopy. The data showed that the cytosol fraction contained the highest relative specific activity for the hydroxysteroid dehydrogenases required for the formation of the diols. The cytosol fraction also contained the highest total activity. The enzymes required for the formation of ethinyl estradiol were distributed equally among mitochondrial and microsomal fractions, however, the highest relative specific activity was associated with the heavy microsomal fraction (18,000 g).^ieng