Conservation genomics of an endangered montane amphibian reveals low population structure, low genomic diversity and selection pressure from disease.

Wildlife diseases are a major global threat to biodiversity. Boreal toads (Anaxyrus [Bufo] boreas) are a state-endangered species in the southern Rocky Mountains of Colorado and New Mexico, and a species of concern in Wyoming, largely due to lethal skin infections caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). We performed conservation and landscape genomic analyses using single nucleotide polymorphisms from double-digest, restriction site-associated DNA sequencing in combination with the development of the first boreal toad (and first North American toad) reference genome to investigate population structure, genomic diversity, landscape connectivity and adaptive divergence. Genomic diversity (π = 0.00034-0.00040) and effective population sizes (Ne = 8.9-38.4) were low, likely due to post-Pleistocene founder effects and Bd-related population crashes over the last three decades. Population structure was also low, likely due to formerly high connectivity among a higher density of geographically proximate populations. Boreal toad gene flow was facilitated by low precipitation, cold minimum temperatures, less tree canopy, low heat load and less urbanization. We found >8X more putatively adaptive loci related to Bd intensity than to all other environmental factors combined, and evidence for genes under selection related to immune response, heart development and regulation and skin function. These data suggest boreal toads in habitats with Bd have experienced stronger selection pressure from disease than from other, broad-scale environmental variations. These findings can be used by managers to conserve and recover the species through actions including reintroduction and supplementation of populations that have declined due to Bd.

Overnight variation in tidal expiratory flow limitation in COPD patients and its correction: an observational study.

BACKGROUND: Tidal expiratory flow limitation (EFLT) is common among COPD patients. Whether EFLT changes during sleep and can be abolished during home ventilation is not known. METHODS: COPD patients considered for noninvasive ventilation used a ventilator which measured within-breath reactance change at 5 Hz (∆Xrs) and adjusted EPAP settings to abolish EFLT. Participants flow limited (∆Xrs > 2.8) when supine underwent polysomnography (PSG) and were offered home ventilation for 2 weeks. The EPAP pressure that abolished EFLT was measured and compared to that during supine wakefulness. Ventilator adherence and subjective patient perceptions were obtained after home use. RESULTS: Of 26 patients with supine EFLT, 15 completed overnight PSG and 10 the home study. In single night and 2-week home studies, EFLT within and between participants was highly variable. This was unrelated to sleep stage or body position with only 14.6% of sleep time spent within 1 cmH2O of the awake screening pressure. Over 2 weeks, mean EPAP was almost half the mean maximum EPAP (11.7 vs 6.4 cmH2O respectively). Group mean ∆Xrs was ≤ 2.8 for 77.3% of their home use with a mean time to abolish new EFLT of 5.91 min. Adherence to the ventilator varied between 71 and 100% in prior NIV users and 36-100% for naïve users with most users rating therapy as comfortable. CONCLUSIONS: Tidal expiratory flow limitation varies significant during sleep in COPD patients. This can be controlled by auto-titrating the amount of EPAP delivered. This approach appears to be practical and well tolerated by patients. TRIAL REGISTRATION: The trial was retrospectively registered at CT.gov NCT04725500.

Reamed locked intramedullary nailing for studying femur fracture and its complications.

Morbidity associated with femur fractures in polytrauma patients is known to be high. The many unsolved clinical questions include the immunological effect of the fracture and its fixation, timing of fracture fixation, management of fracture non-union, effect of infection and critical size of bone defects. The aim of this study was to establish a clinically-relevant and reproducible animal model with regards to histological, biomechanical and radiological changes during bone healing. A custom-designed intramedullary nail with interlocking system (RabbitNail, RISystem AG, Davos Platz, Switzerland) was used for fixation, following femur fracture. New Zealand White rabbits were assigned to two groups: 1. closed fracture model (CF; non-survival model: n = 6, survival model: n = 3) with unilateral mid-shaft femur fracture created by blunt force; 2. osteotomy model (OT; survival model: n = 14) with unilateral transverse osteotomy creating femur fracture. There were no intraoperative complications and full-weight bearing was achieved in all survival rabbits. Significant periosteal reaction and callus formation were confirmed from 2 weeks postoperatively, with a significant volume formation (739.59 ± 62.14 mm3) at 8 weeks confirmed by micro-computed tomography (µ-CT). 2 months after fixation, there was no difference between the osteotomised and contralateral control femora in respect to the maximum torque (3.47 ± 0.35 N m vs. 3.26 ± 0.37 N m) and total energy (21.11 ± 3.09 N m × degree vs. 20.89 ± 2.63 N m × degree) required to break the femur. The data confirmed that a standardised internal fixation technique with an intramedullary nail for closed fracture or osteotomy produced satisfactory bone healing. It was concluded that important clinically-relevant studies can be conducted using this rabbit model.

Peter Joseph Zanetti.

Initially a small animal vet, he worked for the PDSA before becoming a meat inspector.

Compact, single-frequency, doubly resonant optical parametric oscillator pumped in an achromatic phase-adapted double-pass geometry.

We report on a nested-cavity, doubly resonant optical parametric oscillator (NesCOPO) architecture for widely tunable, mid-IR, single-frequency generation. By use of an achromatic phase-adapted double-pass pumping scheme, this new, low-threshold, semimonolithic architecture only requires two free-standing cavity mirrors and a nonlinear crystal with a mirror coating deposited on its input facet while the other facet is antireflection coated. It is thus as simple and compact as any basic linear optical parametric oscillator cavity, is easily tunable, and displays low sensitivity to mechanical vibrations. Using a high-repetition-rate (4.8 kHz) microlaser as the pump source of the NesCOPO, we demonstrate a compact source that provides pulsed, stable single-frequency output over a wide spectral range (3.8-4.3 µm) with a high peak power (up to 50 W), which are properties well suited for practical gas sensing applications.

Angiogenic peptides improve blood flow and promote capillary growth in a diabetic and ischaemic mouse model.

OBJECTIVES: It is a common clinical observation that collateral vessel development is impaired in diabetic patients with ischaemic vascular diseases. Consequently, alternative revascularisation strategies in diabetic patients are needed. This study presents the effect and mechanism of new peptide therapeutic angiogenesis in an ischaemic and diabetic mouse model. DESIGN: Streptozocin-injected mice that had undergone hind-limb ischaemia were treated with angiogenic peptides. Blood flow restoration was calculated by laser Doppler imager and corroborated by histological section. For the mechanism study, endothelial cells were exposed to hypoxia and high glucose concentrations to study the effect of the peptides on proliferation and anti-apoptosis. RESULTS: The peptides significantly restored blood perfusion 21 days after surgery in the diabetic mice (p < 0.01) by neo-vascularisation, corroborated by an increase in capillary density. In addition, the peptides induced the proliferation of hypoxic endothelial cells (p < 0.01) and protected the cells from apoptosis in high glucose cultures. CONCLUSIONS: This is the first approach for treatment of ischaemic vascular disease with peptides in a diabetic mouse model.

Author Correction: Direct evidence of Neanderthal fibre technology and its cognitive and behavioral implications.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Direct evidence of Neanderthal fibre technology and its cognitive and behavioral implications.

Neanderthals are often considered as less technologically advanced than modern humans. However, we typically only find faunal remains or stone tools at Paleolithic sites. Perishable materials, comprising the vast majority of material culture items, are typically missing. Individual twisted fibres on stone tools from the Abri du Maras led to the hypothesis of Neanderthal string production in the past, but conclusive evidence was lacking. Here we show direct evidence of fibre technology in the form of a 3-ply cord fragment made from inner bark fibres on a stone tool recovered in situ from the same site. Twisted fibres provide the basis for clothing, rope, bags, nets, mats, boats, etc. which, once discovered, would have become an indispensable part of daily life. Understanding and use of twisted fibres implies the use of complex multi-component technology as well as a mathematical understanding of pairs, sets, and numbers. Added to recent evidence of birch bark tar, art, and shell beads, the idea that Neanderthals were cognitively inferior to modern humans is becoming increasingly untenable.

Virtual conferences.

An interview with Barry Hardy, conducted in May and June 1996 by e-mail and on 12 June 1996 at a MOO site. The development of the Internet has provided the opportunity o f conducting meetings and conferences electronically. In this interview, Barry Hardy outlines the main principles involved in staging and attending a 'virtual meeting', and issues an invitation to the readers o f trends in CELL BIOLOGY to become involved in organizing the first international electronic cell-biology conference.

Spectrin rearrangement early in erythrocyte ghost endocytosis.

The endocytic vacuoles induced in white ghosts were found to be depleted of spectrin and therefore it was proposed that they arose from spectrin-free areas in the erythrocyte membrane. To follow changes in spectrin distribution during endocytosis, affinity-purified rabbit antispectrin antibodies were produced. Quantitative techniques were developed for the use of a highly specific 125I-F(ab')2 antispectrin, and these showed that before the appearance of vacuoles, as assessed by phase microscopy, there was a reproducible decrease in immunoreactive spectrin. To determine whether this spectrin decrease represented a local or diffuse spectrin loss or a spectrin rearrangement, morphologic studies were undertaken using transmission electron microscopy on samples treated with rabbit antispectrin and ferritin-conjugated goat anti-rabbit immunoglobulin. These studies showed that endocytosis was preceded by the creation of extensive spectrin-free areas separated by discrete spectrin-containing zones. Pretreatment of ghosts with alkaline phosphatase blocked all forms of endocytosis and prevented the creation of spectrin-free areas. Therefore, it is proposed that under the impetus of endocytosis inducers, phosphorylated spectrin is redistributed so that spectrin-free zones are created, and that endocytic vacuoles form and fuse in spectrin-free areas.

Molecular dynamics simulations of a lipid bilayer and of hexadecane: an investigation of membrane fluidity.

Molecular dynamics simulations of a fluid-phase dipalmitoyl phosphatidylcholine lipid bilayer in water and of neat hexadecane are reported and compared with nuclear magnetic resonance spin-lattice relaxation and quasi-elastic neutron scattering data. On the 100-picosecond time scale of the present simulations, there is effectively no difference in the reorientational dynamics of the carbons in the membrane interior and in pure hexadecane. Given that the calculated fast reorientational correlation times and the "microscopic" lateral diffusion of the lipids show excellent agreement with the experimental results, it is concluded that the apparently high viscosity of the membrane is more closely related to molecular interactions on the surface rather than in the interior.

The effect of haemorrhagic shock and resuscitation on fracture healing in a rabbit model: an animal study.

Aims: Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship. Materials and Methods: A total of 18 male New Zealand white rabbits underwent femoral osteotomy with intramedullary fixation with 'shock' (n = 9) and control (n = 9) groups. Shock was induced in the study group by removal of 35% of the total blood volume 45 minutes before resuscitation with blood and crystalloid. Fracture healing was monitored for eight weeks using serum markers of healing and radiographs. Results: Four animals were excluded due to postoperative complications. The serum concentration of osteocalcin was significantly elevated in the shock group postoperatively (p < 0.0001). There were otherwise no differences with regard to serum markers of bone healing. The callus index was consistently increased in the shock group on anteroposterior (p = 0.0069) and lateral (p = 0.0165) radiographs from three weeks postoperatively. The control group showed an earlier decrease of callus index. Radiographic scores were significantly greater in the control group (p = 0.0025). Conclusion: In a rabbit femoral osteotomy model with intramedullary fixation, haemorrhagic shock and resuscitation produced larger callus but with evidence of delayed remodelling. Cite this article: Bone Joint J 2018;100-B:1234-40.

A monoclonal antibody against a human B lymphoblastoid cell line induces tumor regression in mice.

We have developed a monoclonal antibody (BAT) to Daudi B lymphoblastoid cell line membranes. The antibody was selected for its ability to stimulate lymphocyte proliferation. Splenocytes of BALB/c or C57BL mice given i.v. injections of 10 micrograms/mouse of BAT exhibited increased proliferation and cytotoxic activity. A single i.v. administration of BAT monoclonal antibody 2 weeks after B16 melanoma cell inoculation resulted in a striking antitumor effect as manifested by the elimination of lung metastases and prolonged survival of the treated mice. BAT monoclonal antibody was also effective in the regression of tumors in mice bearing 3LL (Lewis lung carcinoma) and MCA-105 (fibrosarcoma). Transfer of 10(7)-10(8) splenocytes from mice that had been given injections of BAT to B16- or 3LL-inoculated recipients led to a reduction of lung metastases. Splenocytes from B16-inoculated mice that were cured by BAT were more effective than those from mice treated with BAT alone against recipients bearing either B16 or 3LL tumors. The antitumor activity of BAT is related to its immunostimulatory properties.

Peptide Binding Glucose Regulated Protein 78 Improves Type 1 Diabetes by Preventing Pancreatic ß Cell Apoptosis.

BACKGROUND AND OBJECTIVES: Diabetes Type 1 is characterized by hyperglycemia due to reduced insulin secretion that results from the death of pancreatic ß cells. It was suggested that endoplasmic reticulum (ER) stress is associated with the autoimmune-mediated ß cell destruction. Glucose regulated protein 78 (GRP78) functions as a key regulator to maintain the ER function. Under stress conditions GRP78 is up-regulated and expressed on the cell surface serving as a signaling receptor. Our first objective was to examine the effects of peptide binding cell surface GRP78 to reduce the deleterious effects of diabetes induced by streptozotocin. The second objective was to demonstrate the ability of the peptide to protect the pancreatic ß cells from apoptosis. METHODS: The effect of ADoPep on weight loss, HbA1c levels and anti GRP78 antibody titers was evaluated in a diabetes mouse model. The effect of ADoPep on the pancreatic ß Ins1E cell apoptosis was determined by FACS analysis. RESULTS: The administration of ADoPep to diabetic mice retained the weight loss and reduced HbA1c significantly in 60% of mice. Titers of anti GRP78 antibodies increased in 70% of the treated mice. Apoptosis was significantly inhibited in stressed pancreatic ß Ins 1E cells. CONCLUSIONS: We demonstrate that administration of the peptide ADoPep to diabetic mice improved type 1 diabetes by preventing pancreatic ß cell apoptosis.

A population-based prospective evaluation of risk of sudden cardiac death after operation for common congenital heart defects.

OBJECTIVES: This study sought to define 1) the risk of sudden death after operation for common congenital heart defects; and 2) factors associated with an increased risk of sudden death. BACKGROUND: Although the prognosis for patients with congenital heart defects is improved by surgical treatment, they remain at a well recognized but poorly defined risk of late sudden death. METHODS: This population-based study evaluated all patients < 19 years old undergoing surgical treatment of common forms of congenital heart disease in the state of Oregon between 1958 and 1996. Patients were identified retrospectively through 1958, with prospective biannual follow-up beginning in 1982. The incidence and cause of late sudden death were evaluated for 3,589 patients surviving operation for the following defects: atrial, ventricular and atrioventricular septal defects; patent ductus arteriosus; pulmonary stenosis; aortic stenosis; coarctation of the aorta; tetralogy of Fallot; and D-transposition of the great arteries. RESULTS: There were 41 unexpected late sudden deaths during 45,857 patient-years of follow-up, an overall event rate of 1/1,118 patient-years. Thirty-seven of the 41 late sudden deaths occurred in patients with aortic stenosis, coarctation, transposition of the great arteries or tetralogy of Fallot, an event rate of 1/454 patients-years. In contrast, only four sudden deaths occurred among the other defects, an event rate of 1/7,154 patient-years (p < 0.01). The risk of late sudden death increased incrementally 20 years after operation for tetralogy of Fallot, aortic stenosis and coarctation. However, risk was not dependent on patient age at operation or surgical era. The causes of sudden death were arrhythmia in 30 patients, circulatory (embolic or aneurysm rupture) in 7 and acute heart failure in 4. CONCLUSIONS: The risk of late sudden death for patients surviving operation for common congenital heart defects is 25 to 100 times greater than an age-matched control population. This increased risk is primarily represented by patients with cyanotic or left heart obstructive lesions. The risk of sudden death appears to be time dependent, increasing primarily after the second postoperative decade.

Treatment of ionized hypercalcemia in 12 cats (2006-2008) using PO-administered alendronate.

BACKGROUND: Long-term treatment of cats with ionized hypercalcemia using alendronate has not been evaluated. HYPOTHESIS/OBJECTIVES: Alendronate is well tolerated in treatment of ionized hypercalcemia in cats. ANIMALS: A total of 12 cats with ionized hypercalcemia. METHODS: Prospective study of 12 cats with ionized hypercalcemia of idiopathic origin was identified by telephone and email communication with a convenience sample of consulting veterinarians. Cats were treated with alendronate at a dose of 5-20 mg per feline PO q7d. Serum ionized calcium concentration (iCa) was measured before beginning treatment with alendronate, and after 1, 3, and 6 months of treatment. Alendronate dosage was adjusted according to iCa. Evaluation included physical examination, CBC, biochemistry profile, and diagnostic imaging. The owners and referring veterinarians were questioned about any observed adverse effects. The Wilcoxon matched-pairs signed rank test was used to compare baseline iCa to iCa at different time periods. RESULTS: Alendronate treatment resulted in a decrease in iCa in all 12 cats. The median percentage change in iCa was -13.2%, -15.9%, and -18.1% (range, -29.6 to +7.6; -30.5 to -1.9; -45.8 to +1.5%) at the 1, 3, and 6 month time points, respectively. Baseline iCa was significantly different from 1 month (P = .0042), 3 months (P = .0005), and 6 months (P = .0015). No adverse effects were reported for any of the cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Alendronate was well tolerated and decreased iCa in most cats for the 6-month period of observation.

Interindividual and intraindividual variability in acetylation: characterization with caffeine.

The degree of interindividual and intraindividual variability in acetylator activity was investigated with caffeine used as a probe of enzyme activity. Acetylator phenotype and relative N-acetyltransferase activity were estimated in 46 subjects by measuring the urinary ratio of two metabolites, AFMU/1-MX, after a single 300 mg oral dose of caffeine on five separate occasions. Thirty homozygous slow (rr) and 15 heterozygous rapid (Rr) acetylators were identified. The degree of interindividual variability in acetylator activity was observed to be a mean of 32% (range 27% to 36%) and 20% (range 11% to 29%) in the rr and Rr groups, respectively. The mean intraindividual variation on repetitive measurement was 19% (range 6% to 49%) in the rr and 14% (range 7% to 24%) in the Rr acetylator group. Four subjects had apparent changes in acetylator activity with time such that they were unable to be assigned to any one acetylator group. Two of these four subjects exhibited apparent homozygous rapid acetylator activity intermittently during the 5-week trial. This variability may explain, in part, some of the high degree of patient variability observed in the toxicity, efficacy, and drug-related disease associated with acetylated drugs and environmental toxins.

Pharmacokinetics of high-dose pentobarbital in severe head trauma.

High-dose pentobarbital infusion has been advocated as an effective adjunct in controlling persistent intracranial hypertension after severe head trauma in patients refractory to conventional therapy. Pentobarbital disposition was assessed in 10 adults with severe nonpenetrating head injury after an intravenous loading dose of sodium pentobarbital, 10 mg/kg, infused over 1 hour, followed by a continuous infusion at 0.5 to 3.0 mg/kg/hr provided the cerebral perfusion pressure remained greater than 50 torr. Pharmacokinetic parameters of volume of distribution at steady state (Vss), total body clearance (CL), and t1/2 for the patients with trauma were statistically compared with similar estimates reported for seven adult subjects without head injury. On discontinuation of the pentobarbital infusion, serum concentrations in the patients followed a monoexponential decline with a mean (+/- SD) t1/2 and Vss that were significantly less than values reported for the control subjects (15.6 +/- 3.9 vs. 22.3 +/- 4.0 hours and 44.0 +/- 11.7 vs. 63.4 +/- 15.2 L, respectively). However, there was no significant difference between the mean pentobarbital CL of the patients (2.0 +/- 0.7 L/hr) and the subjects (2.0 +/- 0.4 L/hr). To our knowledge this is the first report on the disposition, elimination, and intrasubject variability of high-dose pentobarbital infusion in adult patients with head trauma.

Eating behavior and plasma beta-endorphin in bulimia.

To study the possible role of plasma beta-endorphin in bulimia, we measured plasma beta-endorphin immunoreactivity in 34 female patients with normal-weight bulimia and 34 normal female controls matched for weight as percent of ideal. Plasma beta-endorphin immunoreactivity in bulimics (mean 59.6 pg/ml; SEM 5.6) was significantly lower (p less than 0.05) than in controls (mean 79.5 pg/ml; SEM 8.5). Within the bulimic group, plasma beta-endorphin immunoreactivity correlated inversely with severity of bulimic symptomatology as measured by the Eating Attitudes Test Bulimia Subscale (p less than 0.05). Endorphin level did not correlate with severity of depression or with percent ideal body weight. Abnormalities in opioid metabolism may be implicated in eating disorders and account for the addictive properties of these disorders.

Activation of lymphocytes by BAT and anti CTLA-4: comparison of binding to T and B cells.

In this study we compare the binding and immune stimulatory properties of BAT and anti CTLA-4 monoclonal antibodies (mAbs). Both antibodies were previously shown to manifest effective immune responses against tumor cells. We have described that BAT antibody, produced against Daudi, a B lymphoblastoid cell line, binds and activates T cells. In this paper we demonstrate that anti CTLA-4, produced against the T-cell activation determinant CTLA-4, binds also to B lymphoblastoid cell lines like Daudi and Raji. Both antibodies do not bind resting B cells. BAT binds resting T lymphocytes as well as activated T lymphocytes, whereas anti CTLA-4 binds only activated T cells. Competitive binding experiments indicate that the binding sites of BAT and anti CTLA-4 on activated T cells are distinct. We have studied the in vitro stimulatory effect of BAT and anti CTLA-4 on lymphocytes cultured with or without tumor cells. In contrast to BAT that increased the proliferation of lymphocytes that have been cultured with tumor cells, anti CTLA-4 did not synergize with tumor cells to enhance lymphocyte proliferation.